WITH PREDEFINED WAVEFORMS

CROSS REFERENCE

[0001] The present Application for Patent claims the benefit of Greek Provisional Patent Application No. 20200100356 by Huang et ak, entitled “BASE STATION ASSISTED UE- TO-UE SIDELINK POSITIONING AND RANGING WITH PREDEFINED WAVEFORMS,” filed June 23, 2020; which is assigned to the assignee hereof.

FIELD OF TECHNOLOGY

[0002] The following relates generally to wireless communications and more specifically to base station assisted user equipment (UE) to UE sidelink positioning and ranging with predefined waveforms.

BACKGROUND

[0003] Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple- access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE). SUMMARY

[0004] The described techniques relate to improved methods, systems, devices, and apparatuses that support base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms. Various described techniques provide for estimation of position information, ranging information, or combinations thereof, through one or more predefined waveforms that are exchanged between UEs in a sidelink communications system. In some cases, UEs may be configured (e.g., by a base station) with a set of periodic resources for transmission of the predefined waveforms. In some cases, a first UE may transmit a first predefined waveform, which may be received at a second UE. The second UE may, responsive to detection of the first predefined waveform, transmit a second predefined waveform, which may be received at the first UE. In some cases, the first UE may use a machine-learning algorithm to estimate a position of the first UE, ranging information between the first UE and the second UE, or combinations thereof. The position/ranging information may be estimated based at least in part on a timing between transmission of the first predefined waveform and receipt of the second predefined waveform. In some cases, the first predefined waveform, the second predefined waveform, or both, may provide information related to position, speed, and/or movement direction of the UE that transmits the predefined waveform.

[0005] The first UE may transmit an indication of the estimated position/ranging information to the base station, which may determine an update to the estimated position/ranging information, and provide the updated estimate to the first UE. The first UE may then provide the updated estimate to the machine learning algorithm for use in providing subsequent position/ranging estimates. In some cases, the base station may collect position/ranging information from a number of UEs and fuse the information to provide updates to the position/ranging information of each UE, which is transmitted to the UEs and used to update the machine-learning algorithms at the UEs. The predefined waveform may be selected to be identified at a UE with little or no digital processing. In some cases, the predefined waveform is an analog-domain waveform that is transmitted and detected using analog components in an RF front end of the UEs. In some cases, a set of predefined waveforms may be configured, with each waveform in the set mapped to a different combination of position and direction of travel of the transmitting UE, such that the transmitting UE can select the appropriate waveform for transmission and the receiving UE can use the identified waveform to identify the indicated position and direction of travel.

[0006] A method of wireless communication at a first UE is described. The method may include transmitting, to a second UE, a first waveform in a set of periodic wireless resources, detecting, responsive to the transmitting the first waveform, one or more instance of a second waveform from the second UE, where the first waveform and the second waveform are predetermined waveforms, determining one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE, transmitting an indication of one or more of the position of the first UE or the ranging information to a base station, and receiving, from the base station, one or more of an updated position of the first UE or updated ranging information associated with the second UE.

[0007] An apparatus for wireless communication at a first UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to transmit, to a second UE, a first waveform in a set of periodic wireless resources, detect, responsive to the transmitting the first waveform, one or more instance of a second waveform from the second UE, where the first waveform and the second waveform are predetermined waveforms, determine one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE, transmit an indication of one or more of the position of the first UE or the ranging information to a base station, and receive, from the base station, one or more of an updated position of the first UE or updated ranging information associated with the second UE.

[0008] Another apparatus for wireless communication at a first UE is described. The apparatus may include means for transmitting, to a second UE, a first waveform in a set of periodic wireless resources, detecting, responsive to the transmitting the first waveform, one or more instance of a second waveform from the second UE, where the first waveform and the second waveform are predetermined waveforms, determining one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE, transmitting an indication of one or more of the position of the first UE or the ranging information to a base station, and receiving, from the base station, one or more of an updated position of the first UE or updated ranging information associated with the second UE. [0009] A non-transitory computer-readable medium storing code for wireless communication at a first UE is described. The code may include instructions executable by a processor to transmit, to a second UE, a first waveform in a set of periodic wireless resources, detect, responsive to the transmitting the first waveform, one or more instance of a second waveform from the second UE, where the first waveform and the second waveform are predetermined waveforms, determine one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE, transmit an indication of one or more of the position of the first UE or the ranging information to a base station, and receive, from the base station, one or more of an updated position of the first UE or updated ranging information associated with the second UE.

[0010] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the determining may include operations, features, means, or instructions for generating, using a closed-loop machine-learning algorithm, an estimate of one or more of the position of the first UE or the ranging information based on one or more measurements associated with the one or more instance of the second waveform, and where one or more of the updated position or updated ranging information is provided to the closed- loop machine-learning algorithm responsive to the receiving.

[0011] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, from the base station, configuration information that indicates one or more of the first waveform or the second waveform and a periodicity of the set of periodic wireless resources. In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the periodicity of the set of periodic wireless resources corresponds to a periodicity of synchronization signal blocks transmitted by the base station. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the set of periodic wireless resources wireless includes wireless resources having a predetermined time offset from the synchronization signal blocks. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the predetermined time offset is derived based on a cell identification of the base station, a system bandwidth for communications with the base station, or any combinations thereof. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, two or more neighboring base stations have different predetermined time offsets for interference randomization among neighboring base stations.

[0012] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the set of periodic wireless resources has a same periodicity as the periodicity of the synchronization signal blocks, or has a periodicity that is a multiple or factor of the periodicity of the synchronization signal blocks.

[0013] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the configuration information may be received in radio resource control signaling from the base station that indicates a periodicity associated with the set of periodic wireless resources. In some examples of the method, apparatuses, and non- transitory computer-readable medium described herein, the radio resource control signaling includes an indication of one or more of a starting set of resources for the set of periodic wireless resources, a periodicity of the set of periodic wireless resources, an offset from the starting set of resources, or any combinations thereof.

[0014] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for communicating with one or more of the base station or the second UE using a first radio frequency (RF) sub-system that is compliant with a wireless communications standard for data communications between UEs, and where the first waveform is transmitted and the second waveform is received using a second RF sub-system that is noncompliant with the wireless communications standard.

[0015] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, responsive to detecting the second waveform, a third waveform for positioning or ranging procedures for use at the second UE. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the first waveform is transmitted at a first time, and the second waveform is received at the first UE at a second time that is after the first time, and where the third waveform is transmitted at a third time that is a predetermined offset from the second time, and where the second waveform is transmitted following a predetermined offset from a time of receipt of the first waveform at the second UE. In some examples of the method, apparatuses, and non- transitory computer-readable medium described herein, the position of the first UE or ranging information of the distance between the first UE and the second UE is estimated at the first UE based on a time difference between transmitting the first waveform and receiving the second waveform and a speed at which the first waveform propagates between the first UE and the second UE.

[0016] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the position of the first UE or ranging information of the distance between the first UE and the second UE is estimated based on information indicated by the second waveform. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, a set of waveforms is available for use in determining one or more of positioning or ranging information that are each mapped to a different combination of speed and direction of a transmitting UE, and where the information indicated by the first waveform includes a first combination of speed and direction associated with the second UE that is mapped to the first waveform.

[0017] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, each of the first waveform and the second waveform are analog domain waveforms that is processed in analog components of the first UE. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the indication of one or more of the position of the first UE or the ranging information, and the indication of the updated position or updated ranging information, is communicated in one or more of a medium access control (MAC) control element (CE), in control channel communications, in shared channel communications, or any combinations thereof.

[0018] A method of wireless communication at a first UE is described. The method may include detecting one or more instance of a second positioning signal from a second UE, determining, at a machine learning algorithm at the first UE, a first estimate of one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE based on the second positioning signal, transmitting the first estimate to a base station, receiving, from the base station, an updated estimate of one or more of the position of the first UE or ranging information associated with the second UE, and updating the machine learning algorithm based on the updated estimate. [0019] An apparatus for wireless communication at a first UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to detect one or more instance of a second positioning signal from a second UE, determine, at a machine learning algorithm at the first UE, a first estimate of one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE based on the second positioning signal, transmit the first estimate to a base station, receive, from the base station, an updated estimate of one or more of the position of the first UE or ranging information associated with the second UE, and update the machine learning algorithm based on the updated estimate.

[0020] Another apparatus for wireless communication at a first UE is described. The apparatus may include means for detecting one or more instance of a second positioning signal from a second UE, determining, at a machine learning algorithm at the first UE, a first estimate of one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE based on the second positioning signal, transmitting the first estimate to a base station, receiving, from the base station, an updated estimate of one or more of the position of the first UE or ranging information associated with the second UE, and updating the machine learning algorithm based on the updated estimate.

[0021] A non-transitory computer-readable medium storing code for wireless communication at a first UE is described. The code may include instructions executable by a processor to detect one or more instance of a second positioning signal from a second UE, determine, at a machine learning algorithm at the first UE, a first estimate of one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE based on the second positioning signal, transmit the first estimate to a base station, receive, from the base station, an updated estimate of one or more of the position of the first UE or ranging information associated with the second UE, and update the machine learning algorithm based on the updated estimate.

[0022] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the second positioning signal from the second UE includes a predetermined waveform transmitted in a set of periodic wireless resources. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, from the base station, configuration information that indicates one or more waveforms for the second positioning signal, a periodicity of positioning signal transmissions, or any combinations thereof.

[0023] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, prior to receiving the second positioning signal from the second UE, a first positioning signal to at least the second UE, and where the updated estimate received from the base station is based on a set of positioning estimates received from a set of UEs. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, responsive to receiving the second positioning signal from the second UE, a third positioning signal to at least the second UE, and where the updated estimate received from the base station is based on the first estimate transmitted by the first UE and a second estimate from the second UE that is based on the third positioning signal. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, responsive to detecting the second positioning signal, a third positioning signal for positioning or ranging procedures at the second UE, where the second positioning signal is transmitted at a first time and received at the first UE at a first time differential after the first time, and where the third positioning signal is transmitted at a second time that is a predetermined offset from the first time plus the first time differential. In some examples of the method, apparatuses, and non- transitory computer-readable medium described herein, the position of the first UE or ranging information of the distance between the first UE and the second UE is estimated at the first UE based on the first time differential and a speed at which the first positioning signal propagates between the first UE and the second UE, and where the predetermined offset is associated with a processing time for detecting the first positioning signal.

[0024] A method of wireless communication at a base station is described. The method may include configuring a set of periodic wireless resources for transmission of one or more predetermined waveforms between at least a first UE and a second UE, receiving, from the first UE, a first position estimate that is based on a first waveform of the one or more predetermined waveforms that is detected at the first UE and transmitted by the second UE, receiving, from the second UE, a second position estimate that is based on a second waveform of the one or more predetermined waveforms that is detected at the second UE and transmitted by the first UE or a third UE, determining a first updated position estimate for the first UE based on the first position estimate and the second position estimate, and transmitting the first updated position estimate to the first UE.

[0025] An apparatus for wireless communication at a base station is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to configure a set of periodic wireless resources for transmission of one or more predetermined waveforms between at least a first UE and a second UE, receive, from the first UE, a first position estimate that is based on a first waveform of the one or more predetermined waveforms that is detected at the first UE and transmitted by the second UE, receive, from the second UE, a second position estimate that is based on a second waveform of the one or more predetermined waveforms that is detected at the second UE and transmitted by the first UE or a third UE, determine a first updated position estimate for the first UE based on the first position estimate and the second position estimate, and transmit the first updated position estimate to the first UE.

[0026] Another apparatus for wireless communication at a base station is described. The apparatus may include means for configuring a set of periodic wireless resources for transmission of one or more predetermined waveforms between at least a first UE and a second UE, receiving, from the first UE, a first position estimate that is based on a first waveform of the one or more predetermined waveforms that is detected at the first UE and transmitted by the second UE, receiving, from the second UE, a second position estimate that is based on a second waveform of the one or more predetermined waveforms that is detected at the second UE and transmitted by the first UE or a third UE, determining a first updated position estimate for the first UE based on the first position estimate and the second position estimate, and transmitting the first updated position estimate to the first UE.

[0027] A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code may include instructions executable by a processor to configure a set of periodic wireless resources for transmission of one or more predetermined waveforms between at least a first UE and a second UE, receive, from the first UE, a first position estimate that is based on a first waveform of the one or more predetermined waveforms that is detected at the first UE and transmitted by the second UE, receive, from the second UE, a second position estimate that is based on a second waveform of the one or more predetermined waveforms that is detected at the second UE and transmitted by the first UE or a third UE, determine a first updated position estimate for the first UE based on the first position estimate and the second position estimate, and transmit the first updated position estimate to the first UE.

[0028] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the determining may include operations, features, means, or instructions for generating, using a closed-loop machine-learning algorithm, the first updated position estimate of the first UE based on the first position estimate and the second position estimate, where the closed-loop machine-learning algorithm is updated based on one or more subsequent position estimates from the first UE and the second UE. Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, to each of the first UE and the second UE, configuration information that indicates the one or more predetermined waveforms and a periodicity of the set of periodic wireless resources. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the periodicity of the set of periodic wireless resources corresponds to a periodicity of synchronization signal blocks transmitted by the base station.

[0029] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the set of periodic wireless resources wireless includes wireless resources having a predetermined time offset from the synchronization signal blocks. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the predetermined time offset is derived based on a cell identification of the base station, a system bandwidth for communications with the base station, or any combinations thereof. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, two or more neighboring base stations may have different predetermined time offsets for interference randomization among neighboring base stations. In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the set of periodic wireless resources has a same periodicity as the periodicity of the synchronization signal blocks, or has a periodicity that is a multiple or factor of the periodicity of the synchronization signal blocks.

[0030] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the configuration information is transmitted in radio resource control signaling that indicates the periodicity associated with the set of periodic wireless resources. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the radio resource control signaling includes an indication of one or more of a starting set of resources for the set of periodic wireless resources, the periodicity of the set of periodic wireless resources, an offset from the starting set of resources, or any combinations thereof.

[0031] In some examples of the method, apparatuses, and non-transitory computer- readable medium described herein, the second position estimate of the second UE is responsive to the first UE transmitting the second waveform, where the first waveform is transmitted at a first time and received at the first UE at a first time differential after the first time, and where the second waveform is transmitted at a second time that is a predetermined offset from the first time plus the first time differential.

[0032] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for configuring a set of predetermined waveforms for transmission by at least the first UE and the second UE using the set of periodic wireless resources, where each predetermined waveform of the set of predetermined waveforms indicates information usable for position estimation at a receiving UE. In some examples of the method, apparatuses, and non- transitory computer-readable medium described herein, each of the set of waveforms is mapped to a different combination of speed and direction of a transmitting UE, and where the information indicated by the first waveform includes a first combination of speed and direction associated with the second UE that is mapped to the first waveform.

[0033] A method of wireless communication at a base station is described. The method may include receiving, from a first UE, a first position estimate that is based on a first positioning signal that is transmitted by a second UE and is detected at the first UE, receiving, from the second UE, a second position estimate that is based on a second positioning signal that is transmitted by the first UE or a third UE and is detected at the second UE, determining, at a machine learning algorithm at the base station, a first updated position estimate for the first UE based on the first position estimate and the second position estimate, and a second updated position estimate for the second UE based on the first position estimate and the second position estimate, transmitting the first updated position estimate to the first UE and the second updated position estimate to the second UE, and updating the machine learning algorithm based on one or more subsequent position estimates received from the first UE or the second UE.

[0034] An apparatus for wireless communication at a base station is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive, from a first UE, a first position estimate that is based on a first positioning signal that is transmitted by a second UE and is detected at the first UE, receive, from the second UE, a second position estimate that is based on a second positioning signal that is transmitted by the first UE or a third UE and is detected at the second UE, determine, at a machine learning algorithm at the base station, a first updated position estimate for the first UE based on the first position estimate and the second position estimate, and a second updated position estimate for the second UE based on the first position estimate and the second position estimate, transmit the first updated position estimate to the first UE and the second updated position estimate to the second UE, and update the machine learning algorithm based on one or more subsequent position estimates received from the first UE or the second UE.

[0035] Another apparatus for wireless communication at a base station is described. The apparatus may include means for receiving, from a first UE, a first position estimate that is based on a first positioning signal that is transmitted by a second UE and is detected at the first UE, receiving, from the second UE, a second position estimate that is based on a second positioning signal that is transmitted by the first UE or a third UE and is detected at the second UE, determining, at a machine learning algorithm at the base station, a first updated position estimate for the first UE based on the first position estimate and the second position estimate, and a second updated position estimate for the second UE based on the first position estimate and the second position estimate, transmitting the first updated position estimate to the first UE and the second updated position estimate to the second UE, and updating the machine learning algorithm based on one or more subsequent position estimates received from the first UE or the second UE.

[0036] A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code may include instructions executable by a processor to receive, from a first UE, a first position estimate that is based on a first positioning signal that is transmitted by a second UE and is detected at the first UE, receive, from the second UE, a second position estimate that is based on a second positioning signal that is transmitted by the first UE or a third UE and is detected at the second UE, determine, at a machine learning algorithm at the base station, a first updated position estimate for the first UE based on the first position estimate and the second position estimate, and a second updated position estimate for the second UE based on the first position estimate and the second position estimate, transmit the first updated position estimate to the first UE and the second updated position estimate to the second UE, and update the machine learning algorithm based on one or more subsequent position estimates received from the first UE or the second UE.

[0037] Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for configuring a set of periodic wireless resources for transmission of positioning signals, where the positioning signals include one or more predetermined waveforms for transmission in the set of periodic wireless resources. Some examples of the method, apparatuses, and non- transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, to the first UE and the second UE, configuration information that indicates the one or more predetermined waveforms, a periodicity of positioning signal transmissions, or any combinations thereof. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the configuration information is transmitted in radio resource control signaling that indicates the periodicity associated with the set of periodic wireless resources. In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the radio resource control signaling includes an indication of one or more of a starting set of resources for the set of periodic wireless resources, the periodicity of the set of periodic wireless resources, an offset from the starting set of resources, or any combinations thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] FIG. 1 illustrates an example of a system for wireless communications that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. [0039] FIG. 2 illustrates an example of a portion of a wireless communications system that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure.

[0040] FIG. 3 illustrates an example of a periodic positioning signal resources that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure.

[0041] FIG. 4 illustrates an example of a periodic positioning signal resources that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure.

[0042] FIG. 5 illustrates an example of RF subsystems that support base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure.

[0043] FIG. 6 illustrates an example of a process flow that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. [0044] FIGs. 7 and 8 show block diagrams of devices that support base station assisted

UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure.

[0045] FIG. 9 shows a block diagram of a communications manager that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure.

[0046] FIG. 10 shows a diagram of a system including a device that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. [0047] FIGs. 11 and 12 show block diagrams of devices that support base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure.

[0048] FIG. 13 shows a block diagram of a communications manager that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure.

[0049] FIG. 14 shows a diagram of a system including a device that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure.

[0050] FIGs. 15 through 23 show flowcharts illustrating methods that support base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

[0051] Some wireless communications systems may support both access links and sidelinks. An access link is a communication link between a user equipment (UE) and a base station. In some examples, an access link may be referred to as a Uu interface. Specifically, the Uu interface may refer to an over-the-air interface for downlink transmissions, uplink transmissions, or both. A sidelink is a communication link between similar devices and in some cases may be referred to as a PC5 interface. For example, a sidelink may support communications between multiple UEs (e.g., in a vehicle-to-everything (V2X) system, a vehi cl e-to- vehicle (V2V) system, a device-to-device (D2D) system, among other examples) between multiple base stations (e.g., in an integrated access and backhaul (LAB) deployment), or between other types of wireless communications devices. It is noted that while various examples provided herein are discussed for UE sidelink devices, such sidelink techniques may be used for any type of wireless devices that use sidelink communications. For example, a sidelink may support one or more of device-to-device (D2D) communications, vehicle-to- everything (V2X) or vehicle-to-vehicle (V2V) communications, message relaying, discovery signaling, beacon signaling, or other signals transmitted over-the-air from one wireless device to one or more other similar wireless devices. [0052] In some examples, a sidelink device such as a UE may use positioning information (e.g., a physical location of the UE in a reference coordinate system such as the World Geodetic System 1984 (WGS84) or North American Datum of 1983 (NAD83) coordinate system), ranging information (e.g., a relative distance and direction of one or more other UEs), speed information (e.g., rate of travel of the UE, acceleration of the UE, etc.), or combinations thereof, for one or multiple aspects of UE operation. For example, UEs may use directional beamforming for sidelink communications with other UEs, and position/ranging information may be used to select one or more beams, antenna panels, wireless transmission power, and the like, that are to be used for sidelink communications. Additionally or alternatively, position/ranging information may be provided to one or more applications at a UE, which may use the information, alone or in conjunction with positioning/ranging information from one or more other systems (e.g., information from a global positioning system (GPS) module, from a RADAR and/or LIDAR associated with the UE, from one or more optical sensors associated with the UE, etc.). For example, sidelink communications between multiple autonomously or semi-autonomously controlled vehicles (e.g., self-driving cars, aerial drones, etc.) may use information from one or multiple systems to determining position/ranging information for use in control of the vehicle.

[0053] In some cases, multiple redundant systems that provide all or a portion of position information, ranging information, and the like, may be desirable in order to enhance reliability and efficiency of positioning/ranging information. For example, some types of positioning determination systems may be unreliable or unavailable in some situations, such as in darkness (e.g., in which camera-based ranging may have degraded performance), in rain/snow (e.g., in which LIDAR systems may have degraded performance), in areas with reflective clutter (e.g., in which radar systems may have degraded performance), and in tunnels/urban canyons (e.g., which may degrade GPS and radar performance). Further, in deployments with autonomous or semi-autonomous vehicles, some systems may not be able to provide a positive identification associated with the position/proximity/ranging information that may be used to track movements of vehicles relative to one another.

[0054] Various aspects discussed herein provide techniques for estimation of position information, ranging information, or combinations thereof at a UE through one or more predefined waveforms that are exchanged between UEs in a sidelink communications system. In some cases, UEs may be configured (e.g., by a base station) with a set of periodic resources for transmission of the predefined waveforms. In some cases, the set of periodic resources may be configured based on a starting time, offset, and periodicity, or in resources that are at defined offset from synchronization signal block (SSB) resources. In some cases, a first UE may transmit a first predefined waveform, which may be received at a second UE. The second UE may transmit, responsive to detection of the first predefined waveform, a second predefined waveform, which may be received at the first UE. In some cases, the first UE may use a machine-learning algorithm to estimate a position of the first UE, ranging information between the first UE and the second UE (e.g., ranging information that indicates one or more of a distance between the first and second UE, rate of change of the distance between the UEs, relative acceleration of the UEs, and the like), or combinations thereof. The position/ranging information may be estimated based at least in part on a timing between transmission of the first predefined waveform and receipt of the second predefined waveform. In some cases, the first predefined waveform, the second predefined waveform, or both, may provide information related to position, speed, and/or movement direction of the UE that transmits the predefined waveform. In some examples, a pool of predefined waveforms may be provided in which each predefined waveform of the pool is mapped to a different combination of speed and movement direction, and the transmitted waveform may be selected based at least in part on the mapping.

[0055] In some cases, the first UE may transmit an indication of the estimated position/ranging information to the base station, and the base station may determine an update to the estimated position/ranging information. The base station may provide the updated estimate to the first UE. The first UE may then provide the updated estimate to the machine learning algorithm for use in providing subsequent position/ranging estimates, thus providing feedback for continued learning at the machine learning algorithm. In some cases, the base station may collect position/ranging information from a number of UEs and fuse the information to provide updates to the position/ranging information of each UE, which is transmitted to the UEs and used to update the machine-learning algorithms at the UEs. The predefined waveform may be selected to be identified at a UE with little or no digital processing. In some cases, the predefined waveform is an analog-domain waveform that is transmitted and detected using analog components in an RF front end of the UEs.

[0056] Various aspects of the subject matter described herein may be implemented to realize one or more of the following potential advantages. The techniques employed by the described UEs may provide benefits and enhancements to the operation of the UEs. For example, operations performed by the UEs may provide improvements to reliability and efficiency in position determination and ranging of a UE. Such improvements may enhance efficiency of wireless communications at a UE by allowing for adjustments to transmission/reception parameters based on an estimated location of one or more other UEs. In some examples, such improvements may support autonomous or semi-autonomous decision making at the UE based on positioning information, ranging information, or combinations thereof. The described techniques may thus include features for improvements to reliability in communications, enhanced communications efficiency position/ranging information, and, in some examples, may promote enhanced reliability for applications that may use positioning and ranging information, among other benefits.

[0057] Aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are further illustrated by and described with reference to wireless resources for transmission of positioning signals, apparatus diagrams, system diagrams, and flowcharts that relate to base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms.

[0058] FIG. 1 illustrates an example of a wireless communications system 100 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. The wireless communications system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communications system 100 may be a Long Term Evolution (LTE) network, an LTE- Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communications system 100 may support enhanced broadband communications, ultra reliable (e.g., mission critical) communications, low latency communications, communications with low-cost and low-complexity devices, or any combination thereof.

[0059] The base stations 105 may be dispersed throughout a geographic area to form the wireless communications system 100 and may be devices in different forms or having different capabilities. The base stations 105 and the UEs 115 may wirelessly communicate via one or more communication links 125. Each base station 105 may provide a coverage area 110 over which the UEs 115 and the base station 105 may establish one or more communication links 125. The coverage area 110 may be an example of a geographic area over which a base station 105 and a UE 115 may support the communication of signals according to one or more radio access technologies.

[0060] The UEs 115 may be dispersed throughout a coverage area 110 of the wireless communications system 100, and each UE 115 may be stationary, or mobile, or both at different times. The UEs 115 may be devices in different forms or having different capabilities. Some example UEs 115 are illustrated in FIG. 1. The UEs 115 described herein may be able to communicate with various types of devices, such as other UEs 115, the base stations 105, or network equipment (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network equipment), as shown in FIG. 1.

[0061] The base stations 105 may communicate with the core network 130, or with one another, or both. For example, the base stations 105 may interface with the core network 130 through one or more backhaul links 120 (e.g., via an SI, N2, N3, or other interface). The base stations 105 may communicate with one another over the backhaul links 120 (e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations 105), or indirectly (e.g., via core network 130), or both. In some examples, the backhaul links 120 may be or include one or more wireless links.

[0062] One or more of the base stations 105 described herein may include or may be referred to by a person having ordinary skill in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next- generation NodeB or a giga-NodeB (either of which may be referred to as a gNB), a Home NodeB, a Home eNodeB, or other suitable terminology.

[0063] A UE 115 may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client, among other examples. A UE 115 may also include or may be referred to as a personal electronic device such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, a UE 115 may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communications (MTC) device, among other examples, which may be implemented in various objects such as appliances, or vehicles, meters, among other examples.

[0064] The UEs 115 described herein may be able to communicate with various types of devices, such as other UEs 115 that may sometimes act as relays as well as the base stations 105 and the network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, as shown in FIG. 1.

[0065] The UEs 115 and the base stations 105 may wirelessly communicate with one another via one or more communication links 125 over one or more carriers. The term “carrier” may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting the communication links 125. For example, a carrier used for a communication link 125 may include a portion of a radio frequency spectrum band (e.g., a bandwidth part (BWP)) that is operated according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling that coordinates operation for the carrier, user data, or other signaling. The wireless communications system 100 may support communication with a UE 115 using carrier aggregation or multi-carrier operation. A UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used with both frequency division duplexing (FDD) and time division duplexing (TDD) component carriers.

[0066] Signal waveforms transmitted over a carrier may be made up of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT- S-OFDM)). In a system employing MCM techniques, a resource element may consist of one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both). Thus, the more resource elements that a UE 115 receives and the higher the order of the modulation scheme, the higher the data rate may be for the UE 115. A wireless communications resource may refer to a combination of a radio frequency spectrum resource, a time resource, and a spatial resource (e.g., spatial layers or beams), and the use of multiple spatial layers may further increase the data rate or data integrity for communications with a UE 115.

[0067] The time intervals for the base stations 105 or the UEs 115 may be expressed in multiples of a basic time unit which may, for example, refer to a sampling period of T _s =

1 /{ f _{max '} Nf) seconds, where A/ _ma may represent the maximum supported subcarrier spacing, and JV- may represent the maximum supported discrete Fourier transform (DFT) size. Time intervals of a communications resource may be organized according to radio frames each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023).

[0068] Each frame may include multiple consecutively numbered subframes or slots, and each subframe or slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a number of slots. Alternatively, each frame may include a variable number of slots, and the number of slots may depend on subcarrier spacing. Each slot may include a number of symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period). In some wireless communications systems 100, a slot may further be divided into multiple mini-slots containing one or more symbols. Excluding the cyclic prefix, each symbol period may contain one or more (e.g., Nf) sampling periods. The duration of a symbol period may depend on the subcarrier spacing or frequency band of operation.

[0069] A subframe, a slot, a mini-slot, or a symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communications system 100 and may be referred to as a transmission time interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communications system 100 may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)).

[0070] Physical channels may be multiplexed on a carrier according to various techniques. A physical control channel and a physical data channel may be multiplexed on a downlink carrier, for example, using one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET)) for a physical control channel may be defined by a number of symbol periods and may extend across the system bandwidth or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESETs) may be configured for a set of the UEs 115. For example, one or more of the UEs 115 may monitor or search control regions for control information according to one or more search space sets, and each search space set may include one or multiple control channel candidates in one or more aggregation levels arranged in a cascaded manner. An aggregation level for a control channel candidate may refer to a number of control channel resources (e.g., control channel elements (CCEs)) associated with encoded information for a control information format having a given payload size. Search space sets may include common search space sets configured for sending control information to multiple UEs 115 and UE-specific search space sets for sending control information to a specific UE 115.

[0071] Each base station 105 may provide communication coverage via one or more cells, for example a macro cell, a small cell, a hot spot, or other types of cells, or any combination thereof. The term “cell” may refer to a logical communication entity used for communication with a base station 105 (e.g., over a carrier) and may be associated with an identifier for distinguishing neighboring cells (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID), or others). In some examples, a cell may also refer to a geographic coverage area 110 or a portion of a geographic coverage area 110 (e.g., a sector) over which the logical communication entity operates. Such cells may range from smaller areas (e.g., a structure, a subset of structure) to larger areas depending on various factors such as the capabilities of the base station 105. For example, a cell may be or include a building, a subset of a building, or exterior spaces between or overlapping with geographic coverage areas 110, among other examples.

[0072] A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by the UEs 115 with service subscriptions with the network provider supporting the macro cell. A small cell may be associated with a lower-powered base station 105, as compared with a macro cell, and a small cell may operate in the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells may provide unrestricted access to the UEs 115 with service subscriptions with the network provider or may provide restricted access to the UEs 115 having an association with the small cell (e.g., the UEs 115 in a closed subscriber group (CSG), the UEs 115 associated with users in a home or office). A base station 105 may support one or multiple cells and may also support communications over the one or more cells using one or multiple component carriers.

[0073] In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., MTC, narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB)) that may provide access for different types of devices.

[0074] In some examples, a base station 105 may be movable and therefore provide communication coverage for a moving geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, but the different geographic coverage areas 110 may be supported by the same base station 105. In other examples, the overlapping geographic coverage areas 110 associated with different technologies may be supported by different base stations 105. The wireless communications system 100 may include, for example, a heterogeneous network in which different types of the base stations 105 provide coverage for various geographic coverage areas 110 using the same or different radio access technologies.

[0075] Some UEs 115, such as MTC or IoT devices, may be low cost or low complexity devices and may provide for automated communication between machines (e.g., via Machine-to-Machine (M2M) communication). M2M communication or MTC may refer to data communication technologies that allow devices to communicate with one another or a base station 105 without human intervention. In some examples, M2M communication or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay such information to a central server or application program that makes use of the information or presents the information to humans interacting with the application program. Some UEs 115 may be designed to collect information or enable automated behavior of machines or other devices. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction- based business charging.

[0076] Some UEs 115 may be configured to employ operating modes that reduce power consumption, such as half-duplex communications (e.g., a mode that supports one-way communication via transmission or reception, but not transmission and reception simultaneously). In some examples, half-duplex communications may be performed at a reduced peak rate. Other power conservation techniques for the UEs 115 include entering a power saving deep sleep mode when not engaging in active communications, operating over a limited bandwidth (e.g., according to narrowband communications), or a combination of these techniques. For example, some UEs 115 may be configured for operation using a narrowband protocol type that is associated with a defined portion or range (e.g., set of subcarriers or resource blocks (RBs)) within a carrier, within a guard-band of a carrier, or outside of a carrier.

[0077] The wireless communications system 100 may be configured to support ultra reliable communications or low-latency communications, or various combinations thereof. For example, the wireless communications system 100 may be configured to support ultra reliable low-latency communications (URLLC) or mission critical communications. The UEs 115 may be designed to support ultra-reliable, low-latency, or critical functions (e.g., mission critical functions). Ultra-reliable communications may include private communication or group communication and may be supported by one or more mission critical services such as mission critical push-to-talk (MCPTT), mission critical video (MCVideo), or mission critical data (MCData). Support for mission critical functions may include prioritization of services, and mission critical services may be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission critical, and ultra-reliable low- latency may be used interchangeably herein.

[0078] In some examples, a UE 115 may also be able to communicate directly with other UEs 115 over a device-to-device (D2D) communication link 135 (e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UEs 115 utilizing D2D communications may be within the geographic coverage area 110 of a base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of a base station 105 or be otherwise unable to receive transmissions from a base station 105. In some examples, groups of the UEs 115 communicating via D2D communications may utilize a one-to-many (1 :M) system in which each UE 115 transmits to every other UE 115 in the group. In some examples, a base station 105 facilitates the scheduling of resources for D2D communications. In other cases, D2D communications are carried out between the UEs 115 without the involvement of a base station 105. [0079] In some systems, the D2D communication link 135 may be an example of a communication channel, such as a sidelink communication channel, between vehicles (e.g., UEs 115). In some examples, vehicles may communicate using vehicle-to-everything (V2X) communications, vehicle-to-vehicle (V2V) communications, or some combination of these. A vehicle may signal information related to traffic conditions, signal scheduling, weather, safety, emergencies, or any other information relevant to a V2X system. In some examples, vehicles in a V2X system may communicate with roadside infrastructure, such as roadside units, or with the network via one or more network nodes (e.g., base stations 105) using vehicle-to-network (V2N) communications, or with both.

[0080] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) or 5G core (5GC), which may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW), a Packet Data Network (PDN) gateway (P-GW), or a user plane function (UPF)). The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for the UEs 115 served by the base stations 105 associated with the core network 130. User IP packets may be transferred through the user plane entity, which may provide IP address allocation as well as other functions. The user plane entity may be connected to the network operators IP services 150. The operators IP services 150 may include access to the Internet, Intranet(s), an IP Multimedia Subsystem (IMS), or a Packet- Switched Streaming Service.

[0081] Some of the network devices, such as a base station 105, may include subcomponents such as an access network entity 140, which may be an example of an access node controller (ANC). Each access network entity 140 may communicate with the UEs 115 through one or more other access network transmission entities 145, which may be referred to as radio heads, smart radio heads, or transmission/reception points (TRPs). Each access network transmission entity 145 may include one or more antenna panels. In some configurations, various functions of each access network entity 140 or base station 105 may be distributed across various network devices (e.g., radio heads and ANCs) or consolidated into a single network device (e.g., a base station 105). [0082] The wireless communications system 100 may operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from approximately one decimeter to one meter in length. The UHF waves may be blocked or redirected by buildings and environmental features, but the waves may penetrate structures sufficiently for a macro cell to provide service to the UEs 115 located indoors. The transmission of UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.

[0083] The wireless communications system 100 may also operate in a super high frequency (SHF) region using frequency bands from 3 GHz to 30 GHz, also known as the centimeter band, or in an extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz), also known as the millimeter band. In some examples, the wireless communications system 100 may support millimeter wave (mmW) communications between the UEs 115 and the base stations 105, and EHF antennas of the respective devices may be smaller and more closely spaced than UHF antennas. In some examples, this may facilitate use of antenna arrays within a device. The propagation of EHF transmissions, however, may be subject to even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions that use one or more different frequency regions, and designated use of bands across these frequency regions may differ by country or regulating body.

[0084] The wireless communications system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communications system 100 may employ License Assisted Access (LAA), LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz industrial, scientific, and medical (ISM) band. When operating in unlicensed radio frequency spectrum bands, devices such as the base stations 105 and the UEs 115 may employ carrier sensing for collision detection and avoidance. In some examples, operations in unlicensed bands may be based on a carrier aggregation configuration in conjunction with component carriers operating in a licensed band (e.g., LAA). Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among other examples.

[0085] A base station 105 or a UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of a base station 105 or a UE 115 may be located within one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, antennas or antenna arrays associated with a base station 105 may be located in diverse geographic locations. A base station 105 may have an antenna array with a number of rows and columns of antenna ports that the base station 105 may use to support beamforming of communications with a UE 115. Likewise, a UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations. Additionally or alternatively, an antenna panel may support radio frequency beamforming for a signal transmitted via an antenna port.

[0086] The base stations 105 or the UEs 115 may use MIMO communications to exploit multipath signal propagation and increase the spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such techniques may be referred to as spatial multiplexing. The multiple signals may, for example, be transmitted by the transmitting device via different antennas or different combinations of antennas. Likewise, the multiple signals may be received by the receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers may be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO), where multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO), where multiple spatial layers are transmitted to multiple devices.

[0087] Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station 105, a UE 115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that some signals propagating at particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying amplitude offsets, phase offsets, or both to signals carried via the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation).

[0088] A base station 105 or a UE 115 may use beam sweeping techniques as part of beam forming operations. For example, a base station 105 may use multiple antennas or antenna arrays (e.g., antenna panels) to conduct beamforming operations for directional communications with aUE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station 105 multiple times in different directions. For example, the base station 105 may transmit a signal according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used to identify (e.g., by a transmitting device, such as a base station 105, or by a receiving device, such as a UE 115) a beam direction for later transmission or reception by the base station 105.

[0089] Some signals, such as data signals associated with a particular receiving device, may be transmitted by a base station 105 in a single beam direction (e.g., a direction associated with the receiving device, such as a UE 115). In some examples, the beam direction associated with transmissions along a single beam direction may be determined based on a signal that was transmitted in one or more beam directions. For example, a UE 115 may receive one or more of the signals transmitted by the base station 105 in different directions and may report to the base station 105 an indication of the signal that the UE 115 received with a highest signal quality or an otherwise acceptable signal quality.

[0090] In some examples, transmissions by a device (e.g., by a base station 105 or a UE 115) may be performed using multiple beam directions, and the device may use a combination of digital precoding or radio frequency beamforming to generate a combined beam for transmission (e.g., from a base station 105 to a UE 115). The UE 115 may report feedback that indicates precoding weights for one or more beam directions, and the feedback may correspond to a configured number of beams across a system bandwidth or one or more sub-bands. The base station 105 may transmit a reference signal (e.g., a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS)), which may be precoded or unprecoded. The UE 115 may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., a multi-panel type codebook, a linear combination type codebook, a port selection type codebook). Although these techniques are described with reference to signals transmitted in one or more directions by a base station 105, a UE 115 may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE 115) or for transmitting a signal in a single direction (e.g., for transmitting data to a receiving device).

[0091] A receiving device (e.g., a UE 115) may try multiple receive configurations (e.g., directional listening) when receiving various signals from the base station 105, such as synchronization signals, reference signals, beam selection signals, or other control signals.

For example, a receiving device may try multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets (e.g., different directional listening weight sets) applied to signals received at multiple antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as “listening” according to different receive configurations or receive directions. In some examples, a receiving device may use a single receive configuration to receive along a single beam direction (e.g., when receiving a data signal). The single receive configuration may be aligned in a beam direction determined based on listening according to different receive configuration directions (e.g., a beam direction determined to have a highest signal strength, highest signal-to-noise ratio (SNR), or otherwise acceptable signal quality based on listening according to multiple beam directions).

[0092] The wireless communications system 100 may be a packet-based network that operates according to a layered protocol stack. In the user plane, communications at the bearer or Packet Data Convergence Protocol (PDCP) layer may be IP -based. A Radio Link Control (RLC) layer may perform packet segmentation and reassembly to communicate over logical channels. A Medium Access Control (MAC) layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may also use error detection techniques, error correction techniques, or both to support retransmissions at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer may provide establishment, configuration, and maintenance of an RRC connection between a UE 115 and a base station 105 or a core network 130 supporting radio bearers for user plane data. At the physical layer, transport channels may be mapped to physical channels.

[0093] In some cases, multiple UEs 115 may implement sidelink communications for direct UE-to-UE exchange of information. Such UEs 115, in accordance with various described techniques, may determine estimations of position information, ranging information, or combinations thereof, through one or more predefined waveforms that are exchanged between UEs 115 in sidelink communications. In some cases, UEs 115 may be configured (e.g., by a base station 105) with a set of periodic resources for transmission of the predefined waveforms. In some cases, a first UE 115 may transmit a first predefined waveform, which may be received at a second UE 115. The second UE 115 may, responsive to detection of the first predefined waveform, transmit a second predefined waveform, which may be received at the first UE 115. In some cases, the first UE 115 may use a machine learning algorithm to estimate a position of the first UE 115, ranging information between the first UE 115 and the second UE 115, or combinations thereof. The position/ranging information may be estimated based at least in part on a timing between transmission of the first predefined waveform and receipt of the second predefined waveform. In some cases, the first predefined waveform, the second predefined waveform, or both, may provide information related to position, speed, and/or movement direction of the UE that transmits the predefined waveform.

[0094] In some cases, the base station 105 may receive position estimates of multiple UEs 115 and determine updates to the estimated position/ranging information, and provide the updated estimate to the corresponding UEs. The UEs 115 may then provide the updated estimate to the machine learning algorithm for use in providing subsequent position/ranging estimates. In some cases, the base station 105 may collect position/ranging information from a number of UEs 115 and fuse the information to provide updates to the position/ranging information of each UE 115. The predefined waveform may be selected to be identified at a UE 115 with little or no digital processing. In some cases, the predefined waveform is an analog-domain waveform that is transmitted and detected using analog components in an RF front end of the UEs 115. In some cases, a set of predefined waveforms may be configured, with each waveform in the set mapped to a different combination of position and direction of travel of the transmitting UE 115, such that the transmitting UE 115 can select the appropriate waveform for transmission and the receiving UE 115 can use the identified waveform to identify the indicated position and direction of travel.

[0095] FIG. 2 illustrates an example of a wireless communications system 200 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. In some examples, wireless communications system 200 may implement aspects of wireless communications system 100. Wireless communications system 200 may include a base station 105-a, a first UE 115-a and a second UE 115-b, which may be examples of a base station 105 and UEs 115, respectively, described with reference to FIG. 1. In some cases, the group of UEs 115 may communicate with each other (e.g., within a V2X system, a D2D system, and the like) via sidelink communications.

[0096] In this example, each of the UEs 115 may be in a coverage area 110-a (e.g., a coverage area 110 with reference to FIG. 1) of the base station 105. In other examples, one or more UEs 115 may be outside of the coverage area 110-a. The first UE 115-a and the second UE 115-b may communicate with the base station 105-a via an access link (e.g., a Uu link) that may be used to provide downlink communications 205 and uplink communications 210. Further, UEs 115 may establish a sidelink 215 (e.g., a PC5 link) that may be used for direct communications between the first UE 115-a and the second UE 115-b.

[0097] In some cases, the base station 105-a may provide configuration information 220 to the UEs 115 (e.g., in RRC signaling during establishment of sidelink communications) that may configure positioning and ranging information determination at the UEs. In some cases, UEs 115 may be configured with a set of periodic resources for transmission of predefined waveforms 235. In some cases, as discussed in more detail with reference to FIG. 3, the set of periodic resources may be configured in resources that are at a defined offset from synchronization signal block (SSB) resources. In such cases, for each SSB, associated resources for communication of predefined waveform 235 may occur at a configured offset (e.g., a configured number of symbols) from a starting or ending symbol of the SSB resources. In other cases, as will be discussed in more detail with reference to FIG. 4, the set of periodic resources may be configured (e.g., via RRC signaling) based on a starting time, an offset, and a periodicity.

[0098] In some cases, the first UE 115 -a may transmit a first predefined waveform 235 -a, which may be received at a second UE 115-b. The second UE 115-b may transmit, responsive to detection of the first predefined waveform 235-a, a second predefined waveform 235-b, which may be received at the first UE 115-a. In some cases, the first UE may use a machine-learning algorithm to estimate a position of the first UE 115-a, ranging information between the first UE 115-a and the second UE 115-b (e.g., ranging information that indicates one or more of a distance between the first UE 115-a and second UE 115-b, rate of change of the distance between the UEs 115, relative acceleration of the UEs 115, and the like), or combinations thereof. The position/ranging information may be estimated based at least in part on a timing between transmission of the first predefined waveform 235-a and receipt of the second predefined waveform 235-b. For example, such timing may be associated with a propagation time of the over-the-air signal from the first UE 115-a to the second UE 115-b and back, and an amount of processing time associated with the second UE 115-b detecting the first predefined waveform 235-a and starting the transmission of the second predefined waveform 235-b. In some cases, the processing time may be a configured delay value or time offset that is provided to allow for consistent and more accurate calculation of the propagation time. In some cases, the first UE 115-a, responsive to detecting the second predefined waveform 235-b, may transmit a third predefined waveform to the second UE 115-b that may be used at the second UE 115-b for determination of position/ranging information at the second UE 115-b.

[0099] In some cases, the first predefined waveform 235-a, the second predefined waveform 235-b, other predefined waveforms, or combinations thereof, may provide information related to position, speed, and/or movement direction of the UE 115 that transmits the predefined waveform. In some examples, a pool of predefined waveforms may be provided in which each predefined waveform of the pool is mapped to a different combination of speed and movement direction, and the transmitted waveform may be selected based at least in part on the mapping.

[0100] In some cases, the first UE 115-a may transmit an indication of the estimated position/ranging information 225 to the base station 105-a (e.g., in uplink control information, in a MAC-CE, in a PUSCH transmission, etc.), and the base station 105-a may determine an update to the estimated position/ranging information. The base station 105-a may provide updated position/ranging information 230 to each of the first UE 115-a and the second UE 115-b (e.g., in downlink control information, in a MAC-CE, in a PDSCH transmission, etc.). The UEs 115 may then provide the updated estimate to their respective machine learning algorithm for use in providing subsequent position/ranging estimates, thus providing feedback for continued learning at the machine learning algorithm. In some cases, the base station 105-a may collect position/ranging information from a number of UEs 115 and fuse the information using a machine learning algorithm to provide the updated position/ranging information 230 of each UE, which is transmitted to the UEs 115 and used to update the machine-learning algorithms at the UEs 115. The predefined waveform may be selected to be identified at a UE 115 with little or no digital processing. In some cases, the predefined waveform is an analog-domain waveform that is transmitted and detected using analog components in an RF front end of the UEs.

[0101] In some cases, UEs 115 may include one or more components or sub-systems, which may include a first sub-system with positioning/ranging functionality, and a second sub-system with machine-learning functionality. In some cases, positioning/ranging may be determined, as discussed herein, based on transmission and detection of positioning signals at the UEs 115. As discussed herein, in some cases positioning signals transmitted between UEs may be predefined waveforms 235 (which may also be referred to in some instances as a ‘canned’ waveform) that are readily detectable at a UE 115 with no or relatively little digital processing, which may allow a UE 115 that detects the waveform to transmit a responsive predefined waveform relatively quickly within a set of periodic resources that are configured for positioning signals.

[0102] In the example of FIG. 2, the first UE 115-a may be a requestor, and may transmit first predefined waveform 235-a to the second UE 115-b at time tO. The second UE 115-b may be a responder, and may receive the first predefined waveform 235-a (e.g., based on a single match filter with the predefined waveform set) at time tO + dt , where dt is the amount of time it takes the positioning signal to propagate over the air between the first UE 115-a and the second UE 115-b (i.e., propagation delay). The second UE 115-b may respond by transmitting the second predefined waveform 235-b to the first UE 115-a at time tO + dt + V . In this example, V is the amount of time it takes for the second UE 115-b to transmit the second predefined waveform 235-b upon detection of the first predefined waveform 235-a (which may be referred to as a processing time). In some cases, a value of V is defined or configured as a predetermined offset that is used to determine when to transit a triggered predefined (or predetermined) waveform. The first UE 115-a may receive the second predefined waveform 235-b (e.g., based on a single match filter with the predefined waveform set) at time /7, which corresponds to tO + dt + t’ + dt. The first UE 115-a may then calculate the distance/range between the first UE 115-a and the second UE 115-b by identifying dt (e.g., by calculating ( tl t0 t’) * 0.5) and determining a distance that corresponds with dt (e.g., by calculating dt * the speed of the electrical waveform). In some cases, the value of t’ may be considered to be negligible (e.g., due to a relatively fast turn around by detection and transmission of predefined waveforms 235 in analog RF components at the UEs 115). In other cases, the value of t’ may be a configured or specified constant that is known to each UE 115.

[0103] In some cases, the predefined waveforms 235 may be selected from a set of available predefined waveforms based on one or more characteristics of the UE 115 that is to transmit the waveform. For example, each predefined waveform in the set of predefined waveforms may be mapped to one or more UE 115 characteristics, such as one or more of speed (e.g., speed in meters/second), direction of travel (e.g., angle of movement of the UE 115 relative to a reference angle such as 0° North in a geomagnetic field), rate of change of speed (e.g., acceleration in m/s ² ), and/or the like. Thus, the size the set of available predefined waveforms set depends on the additional information conveyed by the waveform selection. In some cases, a set of 256 available predefined waveforms may be configured or specified that are mapped to provide four bits of angle information (i.e., one of 16 ranges of angles of travel can be indicated by the waveform selection) and four bits of speed information (i.e., one of 16 ranges of speed can be indicated by the waveform selection). In some cases, each predefined waveform may include different portions that are mapped to different characteristics (e.g., a first half of the predefined waveform may be mapped to a set of speed ranges, and a second half of the predefined waveform may be mapped to angle ranges).

[0104] In some cases, the UEs 115 may use a machine-learning algorithm to determine positioning/ranging information. As discussed, each UE 115 may transmit an estimate of positioning/ranging information 225 to the base station 105-a. The base station 105-a may fuse positioning/ranging information 225 received from multiple UEs 115 and determine updates to received positioning/ranging information 225, and transmit updated positioning/ranging information 230 to each of the UEs 115. This updated positioning/ranging information 230 may be used at each UE 115 to update its machine learning algorithm, thus providing for closed-loop machine learning. In some cases, the machine learning algorithm at the UEs 115 may be seeded based on a training set of information for measured timings as discussed above and associated positioning/ranging outputs. In some cases, where the transmitted waveform is selected based on UE characteristics (e.g., speed, angle of travel), such additional information may also be included in the training set of information. Initial estimates of positioning/ranging information may be determined based on the training set of information to provide a coarse estimation, and the updated positioning/ranging information 230 may be fed back into the machine learning algorithm to further tune the output to provide more accurate estimations. In some cases, the machine learning algorithm may be based on a fingerprint of multiple received waveforms from multiple different UEs and associated timings. Additionally, the base station 105-a may also use machine learning to refine positioning/ranging updates that are provided to UEs 115. The machine learning algorithms used at the UEs 115 and base station 105-a may include any of a number of available machine learning algorithms, such as decision tree algorithms, support vector machines, regression analysis-based machine learning, Bayesian network- based machine learning, artificial neural network-based machine learning, and/or the like. Further, in some deployments, one or more stationary transmitters with known locations optionally may be deployed (e.g., base stations or beacons in an area were sidelink communications are heavily used) that transmit certain predefined waveforms in response to detection of a predefined waveform (e.g., in response to detection of the first predefined waveform 235-a). Such transmitters may provide additional inputs to the machine learning algorithms for use in positioning/ranging estimations. [0105] FIG. 3 illustrates an example of a periodic positioning signal resources 300 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. In some examples, periodic positioning signal resources 300 may implement aspects of wireless communications system 100 or 200. In this example, a UE (such as a UE 115 of FIGs. 1 or 2) may be configured to monitor for periodic synchronization signal blocks (SSBs) 305 from one or more base stations (such as base stations 105 of FIGs. 1 or 2), which may be used to identify base stations and associated system information.

[0106] In some cases, UEs may be configured for sidelink communications, and the sidelink configuration may identify that UE positioning/ranging is to be estimated based on measurements associated with transmission and reception of one or more predefined waveforms in accordance with techniques as discussed herein. In some cases, a set of periodic resources for predefined waveforms 310 is provided at part of the sidelink configuration. In the example of FIG. 3, SSB 305 periodicity 320 may be reused as a clock to set up cycles for UE-to-UE range/positioning. In such cases, if the UE successfully reads a SSB 305 at time /, the UE may identify an offset & 315, and the time of t+k slots or symbols may be reserved for UE-to-UE positioning or ranging. In some cases, the sidelink configuration may indicate an explicit value of the offset & 315. In other cases, there is no need for network signaling of the offset & 315, and the offset value may be derived by the UE based on one or more specified parameters, such as cell ID, system bandwidth, etc. Thus, the value of the offset k 315 may be different for adjacent base stations, which may provide for interference randomization among base stations. In other cases, such as illustrated in FIG. 4, a starting time and periodicity may be configured as part of sidelink configuration.

[0107] FIG. 4 illustrates an example of a periodic positioning signal resources 400 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. In some examples, periodic positioning signal resources 400 may implement aspects of wireless communications system 100 or 200. In this example, a UE (such as a UE 115 of FIGs. 1 or 2) may be configured with an explicit periodic starting time 405 and periodicity 420 for UE positioning/ranging.

[0108] In some cases, UEs may be configured with such information as part of sidelink communications configuration, and the sidelink configuration may identify that UE positioning/ranging is to be estimated based on measurements associated with transmission and reception of one or more predefined waveforms in accordance with techniques as discussed herein. In some cases, a set of periodic resources for predefined waveforms 410 is provided at part of the sidelink configuration, where the periodic resources for predefined waveforms 410 occur at an offset k 415 relative to the periodic starting time 405. In some cases, the sidelink configuration may indicate an explicit value of the offset & 415. In other cases, there is no need for network signaling of the offset k 415, and the offset value may be derived by the UE based on one or more specified parameters, such as cell ID, system bandwidth, etc. Thus, the value of the offset k 415 may be different for adjacent base stations, which may provide for interference randomization among base stations.

[0109] FIG. 5 illustrates an example of a RF subsystems 500 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. In some examples, RF subsystems 500 may implement aspects of wireless communications system 100 or 200. As discussed, in some cases UEs (e.g., UEs 115 of FIGs. 1 or 2) may use an RF front end (e.g., analog components of an RF module) to perform fast detection of one or more predefined waveforms for use in positioning/ranging estimations at the UE.

[0110] In this example, a UE transmission/reception controller 505 may include a set of predefined waveforms 510, which may be used for positioning/ranging estimations in accordance with techniques as discussed herein. In some cases, the set of predefined waveforms 510 may include a number of different waveforms that are mapped to different combinations of UE conditions (e.g., combinations of speed and angle of travel). In some cases, a UE may include a standards-compliant RF front end 515, and a non-standards- compliant RF front end 520, each of which may be coupled with one or more antennas 525 (or antenna panels) at the UE. In some cases, the non-standards-compliant RF front end 520 may include analog and/or digital components with an RF matching filter that is set to readily identify a matched RF waveform that is to be used for positioning/ranging. In some cases, the standards-compliant RF front end 515 may be used for communications between the UE and one or more base stations, as well as for sidelink communications between UEs, and the non- standards-compliant RF front end 520 may be used for transmission/reception of predefined waveforms for positioning/ranging. In some cases, even when a UE is not within a coverage area of a base station, the non-standards-compliant RF front end 520 may continue to be used to transmit and receive predefined waveforms that are used for positioning/ranging at the UE. Additionally, portions of a UE RF front end that are standards-compliant and that are non- standards-compliant may be dependent upon the deployment in which the UE is operating, such that in some countries or areas where different frequencies are used for standardized communications and different frequencies may be unlicensed or shared frequencies.

[0111] FIG. 6 illustrates an example of a process flow 600 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. In some examples, process flow 600 may implement aspects of wireless communications system 100 or 200. Process flow 600 may be implemented by a first UE 115-c, a second UE 115-d, and a serving base station 105-b, which may be examples of UEs 115 and base stations 105 as described herein. Alternative examples of the following may be implemented, where some steps are performed in a different order than described or are not performed at all. In some cases, steps may include additional features not mentioned below, or further steps may be added.

[0112] At 605, the first UE 115-c, second UE 115-d, and base station 105-b may establish a sidelink communications connection between the first UE 115-c and second UE 115-d. In some cases, sidelink communications may be configured by the base station 105-b as part of a sidelink connection establishment, and the configuration may include a configuration for UE-to-UE positioning and ranging estimations and closed-loop feedback. In some cases, the configuration information may be provided in RRC signaling as part of configuration information. In some cases, the configuration information may provide information related to a set of periodic resources that are to be used for UE-to-UE positioning signal transmissions, such as transmissions of predefined waveforms in accordance with techniques provided herein. In some cases, the configuration information may also indicate a set of waveforms and a mapping of the different waveforms in the set of waveforms to different UE conditions or parameters (e.g., different combinations of UE speed and angle or direction of travel). In some cases, the configuration information may provide a complete mapping of such a set of waveforms, may provide an index into a predefined codebook for such mapping, or may enable a predefined mapping at the UEs 115.

[0113] At 610, the first UE 115-c may identify periodic resources for predefined waveform transmission and reception. Similarly, at 615 the second UE 115-d may identify the periodic resources for predefined waveform transmission and reception. In some cases, the periodic resources may reuse a periodicity of SSB resources that are configured by the base station 105-b, with an offset (e.g., an offset of k symbols or slots) where the offset may be configured by the base station 105-b or derived based on one or more of a cell ID of the base station or a communications bandwidth (e.g., based on an index value of a combination of cell ID ranges and channel bandwidth for sidelink or access link communications).

[0114] At 620, the first UE 115-c may transmit a first waveform to the second UE 115-d (and/or any other sidelink UEs that may detect the first waveform). In some cases, the first waveform may be selected from the set of configured waveforms based on conditions of the first UE 115-c, such as a speed and direction of travel of the first UE 115-c. At 625, the second UE 115-d may detect the first waveform and trigger transmission of a second waveform. In some cases, the detection of the first waveform may be made at an analog RF front end of the second UE 115-d based on a matching filter that identifies and matches the first waveform. At 630, the second UE 115-d may transmit the second waveform to the first UE 115-c. In some cases, the second waveform may be selected from the set of configured waveforms based on conditions of the second UE 115-d, such as a speed and direction of travel of the second UE 115-d.

[0115] At 635, the first UE 115-c may determine positioning/ranging estimation based on the first and second waveforms. In some cases, the positioning/ranging estimation may be determined using a machine learning algorithm at the first UE 115-c that provides a position estimate of the first UE 115-c (e.g., a UE position in a reference coordinate system, such as WGS 84 or NAD 83) based on a number of current and/or previously received waveforms from other UEs. In some cases, additionally or alternatively to the position estimate, a ranging estimate of a relative location between the first UE 115-c and the second UE 115-d may be determined using the machine learning algorithm at the first UE 115-c. For example, a distance between the UEs may be determined, a relative differential in UE speed may be determined, or combinations thereof. At 640, the first UE 115-c may provide the estimate of the position/ranging information to the base station 105-c (e.g., in uplink control information, in a medium access control (MAC) control element (CE), in uplink shared channel information, or combinations thereof). [0116] Optionally, at 635, the first UE 115-c may also trigger a third waveform transmission. In such cases, at 645, the first UE 115-c may transmit the third waveform to the second UE 115-d. Optionally, at 650, the second UE 115-d may determine a positioning/ranging estimate based on the second and third waveforms. Such a positioning/ranging estimate may be performed in a similar manner as at the first UE 115-c, using a machine learning algorithm at the second UE 115-d. Optionally, at 655, the second UE 115-d may provide its estimate of the position/ranging information to the base station 105-c (e.g., in uplink control information, in a MAC-CE, in uplink shared channel information, or combinations thereof).

[0117] At 660, the base station 105-b may determine positioning/ranging updates for the first UE (and optionally the second UE) based on received UE positioning/ranging estimates. In some cases, a machine learning algorithm may be used at the base station 105-b to update the received estimates from the UE(s) 115, such as by fusing received estimates from multiple UEs together to obtain additional data points for use in determining position/ranging information. In some cases, the base station 105-b may also measure characteristics associated with received signals from the first UE 115-c, such as signal strength and the like, and use such information along with a known location of the base station 105-b to provide an update to the estimated positioning/ranging. At 665, the base station 105-b may transmit first UE updated information to the first UE 115-c (e.g., in downlink control information, in a MAC-CE, in a downlink shared channel transmission, etc.).

[0118] At 670, the first UE 115-c may update the estimated positioning/ranging information based on the updated information from the base station 105-b. In such a manner, a closed-loop machine learning algorithm at the first UE 115-c may perform iterations to provide more accurate estimates for subsequent receptions of predefined waveforms.

[0119] Optionally, at 675, if the base station 105-b received position/ranging information from the second UE 115-d, the base station 105-b may determine an update to the second UE 115-d positioning and ranging. Such an update may be performed in a similar manner as for the first UE 115-c. In such cases, at 680, the base station 105-b may transmit second UE updated information to the second UE 115-d (e.g., in downlink control information, in a MAC-CE, in a downlink shared channel transmission, etc.). At 685, the second UE 115-d may update the estimated positioning/ranging information based on the updated information from the base station 105-b. In such a manner, a closed-loop machine learning algorithm at the second UE 115-d may perform iterations to provide more accurate estimates for subsequent receptions of predefined waveforms.

[0120] At 690, the first UE 115-c and the second UE 115-d may perform sidelink communications. In some cases, one or more communications parameters may be determined based on the position information, ranging information, or combinations thereof. For example, one or more of a beam, antennas, antenna panel, transmission power, or any combinations thereof that are used for transmitting or receiving communications may be determined based on the positioning and/or ranging information.

[0121] FIG. 7 shows a block diagram 700 of a device 705 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. The device 705 may be an example of aspects of a UE 115 as described herein. The device 705 may include a receiver 710, a communications manager 715, and a transmitter 720. The device 705 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

[0122] The receiver 710 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms, etc.). Information may be passed on to other components of the device 705. The receiver 710 may be an example of aspects of the transceiver 1020 described with reference to FIG. 10. The receiver 710 may utilize a single antenna or a set of antennas.

[0123] The communications manager 715 may transmit, to a second UE, a first waveform in a set of periodic wireless resources, detect, responsive to the transmitting the first waveform, one or more instance of a second waveform from the second UE, where the first waveform and the second waveform are predetermined (or predefined) waveforms, determine one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE, receive, from the base station, one or more of an updated position of the first UE or updated ranging information associated with the second UE, and transmit an indication of one or more of the position of the first UE or the ranging information to a base station.

[0124] The communications manager 715 may also detect one or more instance of a second positioning signal from a second UE, determine, at a machine learning algorithm at the first UE, a first estimate of one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE based on the second positioning signal, update the machine learning algorithm based on the updated estimate, transmit the first estimate to a base station, and receive, from the base station, an updated estimate of one or more of the position of the first UE or ranging information associated with the second UE. The communications manager 715 may be an example of aspects of the communications manager 1010 described herein.

[0125] The communications manager 715, or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 715, or its sub-components may be executed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC), a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

[0126] The communications manager 715, or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager 715, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager 715, or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

[0127] The transmitter 720 may transmit signals generated by other components of the device 705. In some examples, the transmitter 720 may be collocated with a receiver 710 in a transceiver module. For example, the transmitter 720 may be an example of aspects of the transceiver 1020 described with reference to FIG. 10. The transmitter 720 may utilize a single antenna or a set of antennas.

[0128] FIG. 8 shows a block diagram 800 of a device 805 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. The device 805 may be an example of aspects of a device 705, or a UE 115 as described herein. The device 805 may include a receiver 810, a communications manager 815, and a transmitter 845. The device 805 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

[0129] The receiver 810 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms, etc.). Information may be passed on to other components of the device 805. The receiver 810 may be an example of aspects of the transceiver 1020 described with reference to FIG. 10. The receiver 810 may utilize a single antenna or a set of antennas.

[0130] The communications manager 815 may be an example of aspects of the communications manager 715 as described herein. The communications manager 815 may include a waveform communication manager 820, a waveform detection manager 825, a position determination manager 830, an uplink communications manager 835, and a machine learning module 840. The communications manager 815 may be an example of aspects of the communications manager 1010 described herein.

[0131] In some cases, the waveform communication manager 820 may transmit, to a second UE, a first waveform in a set of periodic wireless resources. The waveform detection manager 825 may detect, responsive to the transmitting the first waveform, one or more instance of a second waveform from the second UE, where the first waveform and the second waveform are predetermined waveforms. The position determination manager 830 may determine one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE and receive, from the base station, one or more of an updated position of the first UE or updated ranging information associated with the second UE. The uplink communications manager 835 may transmit an indication of one or more of the position of the first UE or the ranging information to a base station.

[0132] In some cases, the waveform communication manager 820 may detect one or more instance of a second positioning signal from a second UE. The machine learning module 840 may determine, at a machine learning algorithm at the first UE, a first estimate of one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE based on the second positioning signal and update the machine learning algorithm based on the updated estimate. The uplink communications manager 835 may transmit the first estimate to a base station. The position determination manager 830 may receive, from the base station, an updated estimate of one or more of the position of the first UE or ranging information associated with the second UE.

[0133] The transmitter 845 may transmit signals generated by other components of the device 805. In some examples, the transmitter 845 may be collocated with a receiver 810 in a transceiver module. For example, the transmitter 845 may be an example of aspects of the transceiver 1020 described with reference to FIG. 10. The transmitter 845 may utilize a single antenna or a set of antennas.

[0134] FIG. 9 shows a block diagram 900 of a communications manager 905 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. The communications manager 905 may be an example of aspects of a communications manager 715, a communications manager 815, or a communications manager 1010 described herein. The communications manager 905 may include a waveform communication manager 910, a waveform detection manager 915, a position determination manager 920, an uplink communications manager 925, a machine learning module 930, a configuration manager 935, and a RRC manager 940. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

[0135] The waveform communication manager 910 may transmit, to a second UE, a first waveform in a set of periodic wireless resources. In some examples, the waveform communication manager 910 may detect one or more instance of a second positioning signal from a second UE. In some examples, the waveform communication manager 910 may transmit, responsive to detecting the second waveform, a third waveform for positioning or ranging procedures for use at the second UE.

[0136] In some examples, the waveform communication manager 910 may communicate with one or more of the base station or the second UE using a first radio frequency (RF) sub system that is compliant with a wireless communications standard for data communications between UEs, and where the first waveform is transmitted and the second waveform is received using a second RF sub-system that is noncompliant with the wireless communications standard.

[0137] In some examples, the waveform communication manager 910 may transmit, responsive to receiving the second positioning signal from the second UE, a third positioning signal to at least the second UE, and where an updated estimate received from the base station is based on the first estimate transmitted by the first UE and a second estimate from the second UE that is based on the third positioning signal.

[0138] In some examples, the waveform communication manager 910 may transmit, responsive to detecting the second positioning signal, a third positioning signal for positioning or ranging procedures at the second UE, where the second positioning signal is transmitted at a first time and received at the first UE at a first time differential after the first time, and where the third positioning signal is transmitted at a second time that is a predetermined offset (e.g., based on a processing time or configured time delay for transmitting the third positioning signal) from the first time plus the first time differential.

[0139] In some cases, the first waveform is transmitted at a first time, and the second waveform is received at the first UE at a second time that is after the first time, and where the third waveform is transmitted at a third time that is a predetermined offset (e.g., based on a processing time or configured time delay for transmitting the third positioning signal) from the second time, and where the second waveform is transmitted following a predetermined offset from a time of receipt of the first waveform at the second UE. In some cases, each of the first waveform and the second waveform are analog domain waveforms that are processed in analog components of the first UE.

[0140] The waveform detection manager 915 may detect, responsive to the transmitting the first waveform, one or more instance of a second waveform from the second UE, where the first waveform and the second waveform are predetermined waveforms. [0141] The position determination manager 920 may determine one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE. In some examples, the position determination manager 920 may receive, from the base station, one or more of an updated position of the first UE or updated ranging information associated with the second UE.

[0142] In some cases, the position of the first UE or ranging information of the distance between the first UE and the second UE is estimated at the first UE based on a time difference between transmitting the first waveform and receiving the second waveform and a speed at which the first waveform propagates between the first UE and the second UE. In some cases, the position of the first UE or ranging information of the distance between the first UE and the second UE is estimated based on information indicated by the second waveform. In some cases, a set of waveforms are available for use in determining one or more of positioning or ranging information that are each mapped to a different combination of speed and direction of a transmitting UE, and where the information indicated by the first waveform includes a first combination of speed and direction associated with the second UE that is mapped to the first waveform.

[0143] In some cases, the position of the first UE or ranging information of the distance between the first UE and the second UE is estimated at the first UE based on the first time differential and a speed at which the first positioning signal propagates between the first UE and the second UE, and where the predetermined offset is associated with a processing time for detecting the first positioning signal.

[0144] The uplink communications manager 925 may transmit an indication of one or more of the position of the first UE or the ranging information to a base station. In some examples, the uplink communications manager 925 may transmit the first estimate to a base station. In some cases, the indication of one or more of the position of the first UE or the ranging information, and the indication of the updated position or updated ranging information, are communicated in one or more of a medium access control (MAC) control element (CE), in control channel communications, in shared channel communications, or any combinations thereof.

[0145] The machine learning module 930 may determine, using a machine learning algorithm at the first UE, a first estimate of one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE based on the second positioning signal. In some examples, the machine learning module 930 may update the machine learning algorithm based on the updated estimate. In some examples, the machine learning module 930 may generate, using a closed-loop machine-learning algorithm, an estimate of one or more of the position of the first UE or the ranging information based on one or more measurements associated with the one or more instance of the second waveform, and where one or more of the updated position or updated ranging information is provided to the closed-loop machine-learning algorithm responsive to the receiving.

[0146] The configuration manager 935 may receive, from the base station, configuration information that indicates one or more of the first waveform or the second waveform and a periodicity of the set of periodic wireless resources. In some examples, two or more neighboring base stations have different predetermined time offsets for interference randomization among neighboring base stations.

[0147] In some examples, the configuration manager 935 may receive, from the base station, configuration information that indicates one or more waveforms for the second positioning signal, a periodicity of positioning signal transmissions, or any combinations thereof. In some cases, the periodicity of the set of periodic wireless resources corresponds to a periodicity of synchronization signal blocks transmitted by the base station. In some cases, the set of periodic wireless resources includes wireless resources having a predetermined time offset from the synchronization signal blocks. In some cases, the predetermined time offset is derived based on a cell identification of the base station, a system bandwidth for communications with the base station, or any combinations thereof. In some cases, the set of periodic wireless resources has a same periodicity as the periodicity of the synchronization signal blocks, or has a periodicity that is a multiple or factor of the periodicity of the synchronization signal blocks.

[0148] The RRC manager 940 may receive and transmit RRC signaling from and to a base station. In some cases, the configuration information is received in radio resource control signaling from the base station that indicates a periodicity associated with the set of periodic wireless resources. In some cases, the radio resource control signaling includes an indication of one or more of a starting set of resources for the set of periodic wireless resources, a periodicity of the set of periodic wireless resources, an offset from the starting set of resources, or any combinations thereof.

[0149] FIG. 10 shows a diagram of a system 1000 including a device 1005 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. The device 1005 may be an example of or include the components of device 705, device 805, or a UE 115 as described herein. The device 1005 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 1010, an I/O controller 1015, a transceiver 1020, an antenna 1025, memory 1030, and a processor 1040. These components may be in electronic communication via one or more buses (e.g., bus 1045).

[0150] The communications manager 1010 may transmit, to a second UE, a first waveform in a set of periodic wireless resources, detect, responsive to the transmitting the first waveform, one or more instance of a second waveform from the second UE, where the first waveform and the second waveform are predetermined waveforms, determine one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE, receive, from the base station, one or more of an updated position of the first UE or updated ranging information associated with the second UE, and transmit an indication of one or more of the position of the first UE or the ranging information to a base station.

[0151] The communications manager 1010 may also detect one or more instance of a second positioning signal from a second UE, determine, at a machine learning algorithm at the first UE, a first estimate of one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE based on the second positioning signal, update the machine learning algorithm based on the updated estimate, transmit the first estimate to a base station, and receive, from the base station, an updated estimate of one or more of the position of the first UE or ranging information associated with the second UE.

[0152] The I/O controller 1015 may manage input and output signals for the device 1005. The I/O controller 1015 may also manage peripherals not integrated into the device 1005. In some cases, the I/O controller 1015 may represent a physical connection or port to an external peripheral. In some cases, the I/O controller 1015 may utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operating system. In other cases, the I/O controller 1015 may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller 1015 may be implemented as part of a processor. In some cases, a user may interact with the device 1005 via the I/O controller 1015 or via hardware components controlled by the I/O controller 1015.

[0153] The transceiver 1020 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 1020 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1020 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

[0154] In some cases, the wireless device may include a single antenna 1025. However, in some cases the device may have more than one antenna 1025, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

[0155] The memory 1030 may include RAM and ROM. The memory 1030 may store computer-readable, computer-executable code 1035 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 1030 may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

[0156] The processor 1040 may include an intelligent hardware device, (e.g., a general- purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor 1040 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into the processor 1040. The processor 1040 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1030) to cause the device 1005 to perform various functions (e.g., functions or tasks supporting base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms). [0157] The code 1035 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 1035 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 1035 may not be directly executable by the processor 1040 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

[0158] FIG. 11 shows a block diagram 1100 of a device 1105 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. The device 1105 may be an example of aspects of a base station 105 as described herein. The device 1105 may include a receiver 1110, a communications manager 1115, and a transmitter 1120. The device 1105 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

[0159] The receiver 1110 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms, etc.). Information may be passed on to other components of the device 1105. The receiver 1110 may be an example of aspects of the transceiver 1420 described with reference to FIG. 14. The receiver 1110 may utilize a single antenna or a set of antennas.

[0160] The communications manager 1115 may configure a set of periodic wireless resources for transmission of one or more predetermined waveforms between at least a first UE and a second UE, receive, from the first UE, a first position estimate that is based on a first waveform of the one or more predetermined waveforms that is detected at the first UE and transmitted by the second UE, receive, from the second UE, a second position estimate that is based on a second waveform of the one or more predetermined waveforms that is detected at the second UE and transmitted by the first UE or a third UE, determine a first updated position estimate for the first UE based on the first position estimate and the second position estimate, and transmit the first updated position estimate to the first UE.

[0161] The communications manager 1115 may also receive, from a first UE, a first position estimate that is based on a first positioning signal that is transmitted by a second UE and is detected at the first UE, receive, from the second UE, a second position estimate that is based on a second positioning signal that is transmitted by the first UE or a third UE and is detected at the second UE, determine, at a machine learning algorithm at the base station, a first updated position estimate for the first UE based on the first position estimate and the second position estimate, and a second updated position estimate for the second UE based on the first position estimate and the second position estimate, update the machine learning algorithm based on one or more subsequent position estimates received from the first UE or the second UE, and transmit the first updated position estimate to the first UE and the second updated position estimate to the second UE. The communications manager 1115 may be an example of aspects of the communications manager 1410 described herein.

[0162] The communications manager 1115, or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 1115, or its sub-components may be executed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC), a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

[0163] The communications manager 1115, or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager 1115, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager 1115, or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

[0164] The transmitter 1120 may transmit signals generated by other components of the device 1105. In some examples, the transmitter 1120 may be collocated with a receiver 1110 in a transceiver module. For example, the transmitter 1120 may be an example of aspects of the transceiver 1420 described with reference to FIG. 14. The transmitter 1120 may utilize a single antenna or a set of antennas.

[0165] FIG. 12 shows a block diagram 1200 of a device 1205 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. The device 1205 may be an example of aspects of a device 1105, or a base station 105 as described herein. The device 1205 may include a receiver 1210, a communications manager 1215, and a transmitter 1240. The device 1205 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

[0166] The receiver 1210 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms, etc.). Information may be passed on to other components of the device 1205. The receiver 1210 may be an example of aspects of the transceiver 1420 described with reference to FIG. 14. The receiver 1210 may utilize a single antenna or a set of antennas.

[0167] The communications manager 1215 may be an example of aspects of the communications manager 1115 as described herein. The communications manager 1215 may include a configuration manager 1220, a position determination manager 1225, a machine learning module 1230, and a downlink communications manager 1235. The communications manager 1215 may be an example of aspects of the communications manager 1410 described herein.

[0168] In some cases, the configuration manager 1220 may configure a set of periodic wireless resources for transmission of one or more predetermined waveforms between at least a first UE and a second UE. The position determination manager 1225 may receive, from the first UE, a first position estimate that is based on a first waveform of the one or more predetermined waveforms that is detected at the first UE and transmitted by the second UE and receive, from the second UE, a second position estimate that is based on a second waveform of the one or more predetermined waveforms that is detected at the second UE and transmitted by the first UE or a third UE. The machine learning module 1230 may determine a first updated position estimate for the first UE based on the first position estimate and the second position estimate. The downlink communications manager 1235 may transmit the first updated position estimate to the first UE.

[0169] In some cases, the position determination manager 1225 may receive, from a first UE, a first position estimate that is based on a first positioning signal that is transmitted by a second UE and is detected at the first UE and receive, from the second UE, a second position estimate that is based on a second positioning signal that is transmitted by the first UE or a third UE and is detected at the second UE. The machine learning module 1230 may determine, at a machine learning algorithm at the base station, a first updated position estimate for the first UE based on the first position estimate and the second position estimate, and a second updated position estimate for the second UE based on the first position estimate and the second position estimate and update the machine learning algorithm based on one or more subsequent position estimates received from the first UE or the second UE. The downlink communications manager 1235 may transmit the first updated position estimate to the first UE and the second updated position estimate to the second UE.

[0170] The transmitter 1240 may transmit signals generated by other components of the device 1205. In some examples, the transmitter 1240 may be collocated with a receiver 1210 in a transceiver module. For example, the transmitter 1240 may be an example of aspects of the transceiver 1420 described with reference to FIG. 14. The transmitter 1240 may utilize a single antenna or a set of antennas.

[0171] FIG. 13 shows a block diagram 1300 of a communications manager 1305 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. The communications manager 1305 may be an example of aspects of a communications manager 1115, a communications manager 1215, or a communications manager 1410 described herein. The communications manager 1305 may include a configuration manager 1310, a position determination manager 1315, a machine learning module 1320, a downlink communications manager 1325, and a RRC manager 1330. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

[0172] The configuration manager 1310 may configure a set of periodic wireless resources for transmission of one or more predetermined waveforms between at least a first UE and a second UE. In some examples, the configuration manager 1310 may transmit, to each of the first UE and the second UE, configuration information that indicates the one or more predetermined waveforms and a periodicity of the set of periodic wireless resources. In some examples, two or more neighboring base stations have different predetermined time offsets for interference randomization among neighboring base stations.

[0173] In some examples, the configuration manager 1310 may configure a set of predetermined waveforms for transmission by at least the first UE and the second UE using the set of periodic wireless resources, where each predetermined waveform of the set of predetermined waveforms indicates information usable for position estimation at a receiving UE.

[0174] In some examples, the configuration manager 1310 may transmit, to the first UE and the second UE, configuration information that indicates the one or more predetermined waveforms, a periodicity of positioning signal transmissions, or any combinations thereof. In some cases, the periodicity of the set of periodic wireless resources corresponds to a periodicity of synchronization signal blocks transmitted by the base station. In some cases, the set of periodic wireless resources includes wireless resources having a predetermined time offset from the synchronization signal blocks. In some cases, the predetermined time offset is derived based on a cell identification of the base station, a system bandwidth for communications with the base station, or any combinations thereof. In some cases, the set of periodic wireless resources has a same periodicity as the periodicity of the synchronization signal blocks, or has a periodicity that is a multiple or factor of the periodicity of the synchronization signal blocks. In some cases, each of the set of waveforms are mapped to a different combination of speed and direction of a transmitting UE, and where the information indicated by the first waveform includes a first combination of speed and direction associated with the second UE that is mapped to the first waveform.

[0175] The position determination manager 1315 may receive, from the first UE, a first position estimate that is based on a first waveform of the one or more predetermined waveforms that is detected at the first UE and transmitted by the second UE. In some examples, the position determination manager 1315 may receive, from the second UE, a second position estimate that is based on a second waveform of the one or more predetermined waveforms that is detected at the second UE and transmitted by the first UE or a third UE. In some examples, the position determination manager 1315 may receive, from a first UE, a first position estimate that is based on a first positioning signal that is transmitted by a second UE and is detected at the first UE.

[0176] In some examples, the position determination manager 1315 may receive, from the second UE, a second position estimate that is based on a second positioning signal that is transmitted by the first UE or a third UE and is detected at the second UE. In some cases, the second position estimate of the second UE is responsive to the first UE transmitting the second waveform, where the first waveform is transmitted at a first time and received at the first UE at a first time differential after the first time, and where the second waveform is transmitted at a second time that is a predetermined offset from the first time plus the first time differential.

[0177] The machine learning module 1320 may determine a first updated position estimate for the first UE based on the first position estimate and the second position estimate. In some examples, the machine learning module 1320 may determine, at a machine learning algorithm at the base station, a first updated position estimate for the first UE based on the first position estimate and the second position estimate, and a second updated position estimate for the second UE based on the first position estimate and the second position estimate. In some examples, the machine learning module 1320 may update the machine learning algorithm based on one or more subsequent position estimates received from the first UE or the second UE. In some examples, the machine learning module 1320 may generate, using a closed-loop machine-learning algorithm, the first updated position estimate of the first UE based on the first position estimate and the second position estimate, where the closed-loop machine-learning algorithm is updated based on one or more subsequent position estimates from the first UE and the second UE.

[0178] The downlink communications manager 1325 may transmit the first updated position estimate to the first UE. In some examples, the downlink communications manager 1325 may transmit the first updated position estimate to the first UE and the second updated position estimate to the second UE.

[0179] The RRC manager 1330 may transmit and receive radio resource control signaling to and from one or more UEs. In some cases, the configuration information is transmitted in radio resource control signaling that indicates the periodicity associated with the set of periodic wireless resources. In some cases, the radio resource control signaling includes an indication of one or more of a starting set of resources for the set of periodic wireless resources, the periodicity of the set of periodic wireless resources, an offset from the starting set of resources, or any combinations thereof.

[0180] FIG. 14 shows a diagram of a system 1400 including a device 1405 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. The device 1405 may be an example of or include the components of device 1105, device 1205, or a base station 105 as described herein. The device 1405 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 1410, a network communications manager 1415, a transceiver 1420, an antenna 1425, memory 1430, a processor 1440, and an inter-station communications manager 1445. These components may be in electronic communication via one or more buses (e.g., bus 1450).

[0181] The communications manager 1410 may configure a set of periodic wireless resources for transmission of one or more predetermined waveforms between at least a first UE and a second UE, receive, from the first UE, a first position estimate that is based on a first waveform of the one or more predetermined waveforms that is detected at the first UE and transmitted by the second UE, receive, from the second UE, a second position estimate that is based on a second waveform of the one or more predetermined waveforms that is detected at the second UE and transmitted by the first UE or a third UE, determine a first updated position estimate for the first UE based on the first position estimate and the second position estimate, and transmit the first updated position estimate to the first UE.

[0182] The communications manager 1410 may also receive, from a first UE, a first position estimate that is based on a first positioning signal that is transmitted by a second UE and is detected at the first UE, receive, from the second UE, a second position estimate that is based on a second positioning signal that is transmitted by the first UE or a third UE and is detected at the second UE, determine, at a machine learning algorithm at the base station, a first updated position estimate for the first UE based on the first position estimate and the second position estimate, and a second updated position estimate for the second UE based on the first position estimate and the second position estimate, update the machine learning algorithm based on one or more subsequent position estimates received from the first UE or the second UE, and transmit the first updated position estimate to the first UE and the second updated position estimate to the second UE.

[0183] The network communications manager 1415 may manage communications with the core network (e.g., via one or more wired backhaul links). For example, the network communications manager 1415 may manage the transfer of data communications for client devices, such as one or more UEs 115.

[0184] The transceiver 1420 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 1420 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1420 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

[0185] In some cases, the wireless device may include a single antenna 1425. However, in some cases the device may have more than one antenna 1425, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

[0186] The memory 1430 may include RAM, ROM, or a combination thereof. The memory 1430 may store computer-readable code 1435 including instructions that, when executed by a processor (e.g., the processor 1440) cause the device to perform various functions described herein. In some cases, the memory 1430 may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

[0187] The processor 1440 may include an intelligent hardware device, (e.g., a general- purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor 1440 may be configured to operate a memory array using a memory controller. In some cases, a memory controller may be integrated into processor 1440. The processor 1440 may be configured to execute computer- readable instructions stored in a memory (e.g., the memory 1430) to cause the device 1405 to perform various functions (e.g., functions or tasks supporting base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms). [0188] The inter-station communications manager 1445 may manage communications with other base station 105, and may include a controller or scheduler for controlling communications with UEs 115 in cooperation with other base stations 105. For example, the inter-station communications manager 1445 may coordinate scheduling for transmissions to UEs 115 for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-station communications manager 1445 may provide an X2 interface within an LTE/LTE-A wireless communication network technology to provide communication between base stations 105.

[0189] The code 1435 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 1435 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 1435 may not be directly executable by the processor 1440 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

[0190] FIG. 15 shows a flowchart illustrating a method 1500 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. The operations of method 1500 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1500 may be performed by a communications manager as described with reference to FIGs. 7 through 10. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special- purpose hardware.

[0191] Optionally, at 1505, the UE may receive, from a base station, configuration information for positioning/ranging. The operations of 1505 may be performed according to the methods described herein. In some examples, aspects of the operations of 1505 may be performed by a configuration manager as described with reference to FIGs. 7 through 10. In some cases, the configuration information may be provided by the base station as part of a sidelink configuration of the UE. In some cases, the configuration information may be received in RRC signaling and indicates one or more of a first waveform or a second waveform and a periodicity of a set of periodic wireless resources. [0192] At 1510, the UE may transmit, to a second UE, a first waveform in a set of periodic wireless resources. The operations of 1510 may be performed according to the methods described herein. In some examples, aspects of the operations of 1510 may be performed by a waveform communication manager as described with reference to FIGs. 7 through 10.

[0193] At 1515, the UE may detect, responsive to the transmitting the first waveform, one or more instance of a second waveform from the second UE, where the first waveform and the second waveform are predetermined waveforms. The operations of 1515 may be performed according to the methods described herein. In some examples, aspects of the operations of 1515 may be performed by a waveform detection manager as described with reference to FIGs. 7 through 10.

[0194] At 1520, the UE may determine one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE. The operations of 1520 may be performed according to the methods described herein. In some examples, aspects of the operations of 1520 may be performed by a position determination manager as described with reference to FIGs. 7 through 10.

[0195] At 1525, the UE may transmit an indication of one or more of the position of the first UE or the ranging information to a base station. The operations of 1525 may be performed according to the methods described herein. In some examples, aspects of the operations of 1525 may be performed by an uplink communications manager as described with reference to FIGs. 7 through 10.

[0196] At 1530, the UE may receive, from the base station, one or more of an updated position of the first UE or updated ranging information associated with the second UE. The operations of 1530 may be performed according to the methods described herein. In some examples, aspects of the operations of 1530 may be performed by a position determination manager as described with reference to FIGs. 7 through 10.

[0197] FIG. 16 shows a flowchart illustrating a method 1600 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. The operations of method 1600 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1600 may be performed by a communications manager as described with reference to FIGs. 7 through 10. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special- purpose hardware.

[0198] At 1605, the UE may receive, from the base station, configuration information that indicates one or more of the first waveform or the second waveform and a periodicity of the set of periodic wireless resources. The operations of 1605 may be performed according to the methods described herein. In some examples, aspects of the operations of 1605 may be performed by a configuration manager as described with reference to FIGs. 7 through 10.

[0199] At 1610, the UE may transmit, to a second UE, a first waveform in a set of periodic wireless resources. The operations of 1610 may be performed according to the methods described herein. In some examples, aspects of the operations of 1610 may be performed by a waveform communication manager as described with reference to FIGs. 7 through 10.

[0200] At 1615, the UE may detect, responsive to the transmitting the first waveform, one or more instance of a second waveform from the second UE, where the first waveform and the second waveform are predetermined waveforms. The operations of 1615 may be performed according to the methods described herein. In some examples, aspects of the operations of 1615 may be performed by a waveform detection manager as described with reference to FIGs. 7 through 10.

[0201] At 1620, the UE may generate, using a closed-loop machine-learning algorithm, an estimate of one or more of the position of the first UE or the ranging information based on one or more measurements associated with the one or more instance of the second waveform, and where one or more of the updated position or updated ranging information is provided to the closed-loop machine-learning algorithm responsive to the receiving. The operations of 1620 may be performed according to the methods described herein. In some examples, aspects of the operations of 1620 may be performed by a machine learning module as described with reference to FIGs. 7 through 10.

[0202] At 1625, the UE may transmit an indication of one or more of the position of the first UE or the ranging information to a base station. The operations of 1625 may be performed according to the methods described herein. In some examples, aspects of the operations of 1625 may be performed by an uplink communications manager as described with reference to FIGs. 7 through 10.

[0203] At 1630, the UE may receive, from the base station, one or more of an updated position of the first UE or updated ranging information associated with the second UE. The operations of 1630 may be performed according to the methods described herein. In some examples, aspects of the operations of 1630 may be performed by a position determination manager as described with reference to FIGs. 7 through 10.

[0204] FIG. 17 shows a flowchart illustrating a method 1700 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. The operations of method 1700 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1700 may be performed by a communications manager as described with reference to FIGs. 7 through 10. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special- purpose hardware.

[0205] At 1705, the UE may transmit, to a second UE, a first waveform in a set of periodic wireless resources. The operations of 1705 may be performed according to the methods described herein. In some examples, aspects of the operations of 1705 may be performed by a waveform communication manager as described with reference to FIGs. 7 through 10.

[0206] At 1710, the UE may detect, responsive to the transmitting the first waveform, one or more instance of a second waveform from the second UE, where the first waveform and the second waveform are predetermined waveforms. The operations of 1710 may be performed according to the methods described herein. In some examples, aspects of the operations of 1710 may be performed by a waveform detection manager as described with reference to FIGs. 7 through 10.

[0207] At 1715, the UE may transmit, responsive to detecting the second waveform, a third waveform for positioning or ranging procedures for use at the second UE. The operations of 1715 may be performed according to the methods described herein. In some examples, aspects of the operations of 1715 may be performed by a waveform communication manager as described with reference to FIGs. 7 through 10.

[0208] At 1720, the UE may determine one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE. The operations of 1720 may be performed according to the methods described herein. In some examples, aspects of the operations of 1720 may be performed by a position determination manager as described with reference to FIGs. 7 through 10.

[0209] At 1725, the UE may transmit an indication of one or more of the position of the first UE or the ranging information to a base station. The operations of 1725 may be performed according to the methods described herein. In some examples, aspects of the operations of 1725 may be performed by an uplink communications manager as described with reference to FIGs. 7 through 10.

[0210] At 1730, the UE may receive, from the base station, one or more of an updated position of the first UE or updated ranging information associated with the second UE. The operations of 1730 may be performed according to the methods described herein. In some examples, aspects of the operations of 1730 may be performed by a position determination manager as described with reference to FIGs. 7 through 10.

[0211] FIG. 18 shows a flowchart illustrating a method 1800 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. The operations of method 1800 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1800 may be performed by a communications manager as described with reference to FIGs. 7 through 10. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special- purpose hardware.

[0212] At 1805, the UE may detect one or more instance of a second positioning signal from a second UE. The operations of 1805 may be performed according to the methods described herein. In some examples, aspects of the operations of 1805 may be performed by a waveform communication manager as described with reference to FIGs. 7 through 10. [0213] At 1810, the UE may determine, at a machine learning algorithm at the first UE, a first estimate of one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE based on the second positioning signal. The operations of 1810 may be performed according to the methods described herein. In some examples, aspects of the operations of 1810 may be performed by a machine learning module as described with reference to FIGs. 7 through 10.

[0214] At 1815, the UE may transmit the first estimate to a base station. The operations of 1815 may be performed according to the methods described herein. In some examples, aspects of the operations of 1815 may be performed by an uplink communications manager as described with reference to FIGs. 7 through 10.

[0215] At 1820, the UE may receive, from the base station, an updated estimate of one or more of the position of the first UE or ranging information associated with the second UE. The operations of 1820 may be performed according to the methods described herein. In some examples, aspects of the operations of 1820 may be performed by a position determination manager as described with reference to FIGs. 7 through 10.

[0216] At 1825, the UE may update the machine learning algorithm based on the updated estimate. The operations of 1825 may be performed according to the methods described herein. In some examples, aspects of the operations of 1825 may be performed by a machine learning module as described with reference to FIGs. 7 through 10.

[0217] FIG. 19 shows a flowchart illustrating a method 1900 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. The operations of method 1900 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1900 may be performed by a communications manager as described with reference to FIGs. 7 through 10. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special- purpose hardware.

[0218] At 1905, the UE may receive, from the base station, configuration information that indicates one or more waveforms for the second positioning signal, a periodicity of positioning signal transmissions, or any combinations thereof. The operations of 1905 may be performed according to the methods described herein. In some examples, aspects of the operations of 1905 may be performed by a configuration manager as described with reference to FIGs. 7 through 10.

[0219] At 1910, the UE may transmit a first positioning signal to at least the second UE. The operations of 1910 may be performed according to the methods described herein. In some examples, aspects of the operations of 1910 may be performed by a waveform communication manager as described with reference to FIGs. 7 through 10. In some cases, the first positioning signal is transmitted prior to receiving a second positioning signal from the second UE, and the second positioning signal is triggered by the first positioning signal.

[0220] At 1915, the UE may detect one or more instance of the second positioning signal from the second UE. The operations of 1915 may be performed according to the methods described herein. In some examples, aspects of the operations of 1915 may be performed by a waveform communication manager as described with reference to FIGs. 7 through 10.

[0221] At 1920, the UE may transmit, responsive to receiving the second positioning signal from the second UE, a third positioning signal to at least the second UE. The operations of 1920 may be performed according to the methods described herein. In some examples, aspects of the operations of 1920 may be performed by a waveform communication manager as described with reference to FIGs. 7 through 10.

[0222] At 1925, the UE may determine, at a machine learning algorithm at the first UE, a first estimate of one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE based on the second positioning signal. The operations of 1925 may be performed according to the methods described herein. In some examples, aspects of the operations of 1925 may be performed by a machine learning module as described with reference to FIGs. 7 through 10.

[0223] At 1930, the UE may transmit the first estimate to a base station. The operations of 1930 may be performed according to the methods described herein. In some examples, aspects of the operations of 1930 may be performed by an uplink communications manager as described with reference to FIGs. 7 through 10.

[0224] At 1935, the UE may receive, from the base station, an updated estimate of one or more of the position of the first UE or ranging information associated with the second UE. The operations of 1935 may be performed according to the methods described herein. In some examples, aspects of the operations of 1935 may be performed by a position determination manager as described with reference to FIGs. 7 through 10. In some cases, the updated estimate received from the base station is based on the first estimate transmitted by the first UE and a second estimate from the second UE that is based on the third positioning signal.

[0225] At 1940, the UE may update the machine learning algorithm based on the updated estimate. The operations of 1940 may be performed according to the methods described herein. In some examples, aspects of the operations of 1940 may be performed by a machine learning module as described with reference to FIGs. 7 through 10.

[0226] FIG. 20 shows a flowchart illustrating a method 2000 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. The operations of method 2000 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 2000 may be performed by a communications manager as described with reference to FIGs. 11 through 14. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

[0227] At 2005, the base station may configure a set of periodic wireless resources for transmission of one or more predetermined waveforms between at least a first UE and a second UE. The operations of 2005 may be performed according to the methods described herein. In some examples, aspects of the operations of 2005 may be performed by a configuration manager as described with reference to FIGs. 11 through 14.

[0228] At 2010, the base station may receive, from the first UE, a first position estimate that is based on a first waveform of the one or more predetermined waveforms that is detected at the first UE and transmitted by the second UE. The operations of 2010 may be performed according to the methods described herein. In some examples, aspects of the operations of 2010 may be performed by a position determination manager as described with reference to FIGs. 11 through 14. [0229] At 2015, the base station may receive, from the second UE, a second position estimate that is based on a second waveform of the one or more predetermined waveforms that is detected at the second UE and transmitted by the first UE or a third UE. The operations of 2015 may be performed according to the methods described herein. In some examples, aspects of the operations of 2015 may be performed by a position determination manager as described with reference to FIGs. 11 through 14.

[0230] At 2020, the base station may determine a first updated position estimate for the first UE based on the first position estimate and the second position estimate. The operations of 2020 may be performed according to the methods described herein. In some examples, aspects of the operations of 2020 may be performed by a machine learning module as described with reference to FIGs. 11 through 14.

[0231] At 2025, the base station may transmit the first updated position estimate to the first UE. The operations of 2025 may be performed according to the methods described herein. In some examples, aspects of the operations of 2025 may be performed by a downlink communications manager as described with reference to FIGs. 11 through 14.

[0232] FIG. 21 shows a flowchart illustrating a method 2100 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. The operations of method 2100 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 2100 may be performed by a communications manager as described with reference to FIGs. 11 through 14. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

[0233] At 2105, the base station may transmit, to each of a first UE and a second UE, configuration information that indicates one or more predetermined waveforms and a periodicity of a set of periodic wireless resources for transmission of the one or more predetermined waveforms. The operations of 2105 may be performed according to the methods described herein. In some examples, aspects of the operations of 2105 may be performed by a configuration manager as described with reference to FIGs. 11 through 14. [0234] At 2110, the base station may receive, from the first UE, a first position estimate that is based on a first waveform of the one or more predetermined waveforms that is detected at the first UE and transmitted by the second UE. The operations of 2110 may be performed according to the methods described herein. In some examples, aspects of the operations of 2110 may be performed by a position determination manager as described with reference to FIGs. 11 through 14.

[0235] At 2115, the base station may receive, from the second UE, a second position estimate that is based on a second waveform of the one or more predetermined waveforms that is detected at the second UE and transmitted by the first UE or a third UE. The operations of 2115 may be performed according to the methods described herein. In some examples, aspects of the operations of 2115 may be performed by a position determination manager as described with reference to FIGs. 11 through 14.

[0236] At 2120, the base station may generate, using a closed-loop machine-learning algorithm, the first updated position estimate of the first UE based on the first position estimate and the second position estimate, where the closed-loop machine-learning algorithm is updated based on one or more subsequent position estimates from the first UE and the second UE. The operations of 2120 may be performed according to the methods described herein. In some examples, aspects of the operations of 2120 may be performed by a machine learning module as described with reference to FIGs. 11 through 14.

[0237] At 2125, the base station may determine a first updated position estimate for the first UE based on the first position estimate and the second position estimate. The operations of 2125 may be performed according to the methods described herein. In some examples, aspects of the operations of 2125 may be performed by a machine learning module as described with reference to FIGs. 11 through 14.

[0238] At 2130, the base station may transmit the first updated position estimate to the first UE. The operations of 2130 may be performed according to the methods described herein. In some examples, aspects of the operations of 2130 may be performed by a downlink communications manager as described with reference to FIGs. 11 through 14.

[0239] FIG. 22 shows a flowchart illustrating a method 2200 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. The operations of method 2200 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 2200 may be performed by a communications manager as described with reference to FIGs. 11 through 14. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

[0240] At 2205, the base station may receive, from a first UE, a first position estimate that is based on a first positioning signal that is transmitted by a second UE and is detected at the first UE. The operations of 2205 may be performed according to the methods described herein. In some examples, aspects of the operations of 2205 may be performed by a position determination manager as described with reference to FIGs. 11 through 14.

[0241] At 2210, the base station may receive, from the second UE, a second position estimate that is based on a second positioning signal that is transmitted by the first UE or a third UE and is detected at the second UE. The operations of 2210 may be performed according to the methods described herein. In some examples, aspects of the operations of 2210 may be performed by a position determination manager as described with reference to FIGs. 11 through 14.

[0242] At 2215, the base station may determine, at a machine learning algorithm at the base station, a first updated position estimate for the first UE based on the first position estimate and the second position estimate, and a second updated position estimate for the second UE based on the first position estimate and the second position estimate. The operations of 2215 may be performed according to the methods described herein. In some examples, aspects of the operations of 2215 may be performed by a machine learning module as described with reference to FIGs. 11 through 14.

[0243] At 2220, the base station may transmit the first updated position estimate to the first UE and the second updated position estimate to the second UE. The operations of 2220 may be performed according to the methods described herein. In some examples, aspects of the operations of 2220 may be performed by a downlink communications manager as described with reference to FIGs. 11 through 14.

[0244] At 2225, the base station may update the machine learning algorithm based on one or more subsequent position estimates received from the first UE or the second UE. The operations of 2225 may be performed according to the methods described herein. In some examples, aspects of the operations of 2225 may be performed by a machine learning module as described with reference to FIGs. 11 through 14.

[0245] FIG. 23 shows a flowchart illustrating a method 2300 that supports base station assisted UE-to-UE sidelink positioning and ranging with predefined waveforms in accordance with aspects of the present disclosure. The operations of method 2300 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 2300 may be performed by a communications manager as described with reference to FIGs. 11 through 14. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

[0246] At 2305, the base station may configure a set of periodic wireless resources for transmission of positioning signals, where the positioning signals include one or more predetermined waveforms for transmission in the set of periodic wireless resources. The operations of 2305 may be performed according to the methods described herein. In some examples, aspects of the operations of 2305 may be performed by a configuration manager as described with reference to FIGs. 11 through 14.

[0247] At 2310, the base station may transmit, to a first UE and a second UE, configuration information that indicates the one or more predetermined waveforms, a periodicity of positioning signal transmissions, or any combinations thereof. The operations of 2310 may be performed according to the methods described herein. In some examples, aspects of the operations of 2310 may be performed by a configuration manager as described with reference to FIGs. 11 through 14.

[0248] At 2315, the base station may receive, from the first UE, a first position estimate that is based on a first positioning signal that is transmitted by the second UE and is detected at the first UE. The operations of 2315 may be performed according to the methods described herein. In some examples, aspects of the operations of 2315 may be performed by a position determination manager as described with reference to FIGs. 11 through 14.

[0249] At 2320, the base station may receive, from the second UE, a second position estimate that is based on a second positioning signal that is transmitted by the first UE or a third UE and is detected at the second UE. The operations of 2320 may be performed according to the methods described herein. In some examples, aspects of the operations of 2320 may be performed by a position determination manager as described with reference to FIGs. 11 through 14.

[0250] At 2325, the base station may determine, at a machine learning algorithm at the base station, a first updated position estimate for the first UE based on the first position estimate and the second position estimate, and a second updated position estimate for the second UE based on the first position estimate and the second position estimate. The operations of 2325 may be performed according to the methods described herein. In some examples, aspects of the operations of 2325 may be performed by a machine learning module as described with reference to FIGs. 11 through 14.

[0251] At 2330, the base station may transmit the first updated position estimate to the first UE and the second updated position estimate to the second UE. The operations of 2330 may be performed according to the methods described herein. In some examples, aspects of the operations of 2330 may be performed by a downlink communications manager as described with reference to FIGs. 11 through 14.

[0252] At 2335, the base station may update the machine learning algorithm based on one or more subsequent position estimates received from the first UE or the second UE. The operations of 2335 may be performed according to the methods described herein. In some examples, aspects of the operations of 2335 may be performed by a machine learning module as described with reference to FIGs. 11 through 14.

[0253] It should be noted that the methods described herein describe possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined.

[0254] The following provides an overview of aspects of the present disclosure:

[0255] Aspect 1 : A method for wireless communication at a first UE, comprising: transmitting, to a second UE, a first waveform in a set of periodic wireless resources; detecting, responsive to the transmitting the first waveform, one or more instance of a second waveform from the second UE, wherein the first waveform and the second waveform are predetermined waveforms; determining one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE; transmitting an indication of one or more of the position of the first UE or the ranging information to a base station; and receiving, from the base station, one or more of an updated position of the first UE or updated ranging information associated with the second UE.

[0256] Aspect 2: The method of aspect 1, wherein the determining comprises: generating, using a closed-loop machine-learning algorithm, an estimate of one or more of the position of the first UE or the ranging information based at least in part on one or more measurements associated with the one or more instance of the second waveform, and wherein one or more of the updated position or updated ranging information is provided to the closed-loop machine-learning algorithm responsive to the receiving.

[0257] Aspect 3: The method of any of aspects 1 through 2, further comprising: receiving, from the base station, configuration information that indicates one or more of the first waveform or the second waveform and a periodicity of the set of periodic wireless resources.

[0258] Aspect 4: The method of aspect 3, wherein the periodicity of the set of periodic wireless resources corresponds to a periodicity of synchronization signal blocks transmitted by the base station.

[0259] Aspect 5: The method of aspect 4, wherein the set of periodic wireless resources includes wireless resources having a predetermined time offset from the synchronization signal blocks.

[0260] Aspect 6: The method of aspect 5, wherein the predetermined time offset is derived based at least in part on a cell identification of the base station, a system bandwidth for communications with the base station, or any combinations thereof.

[0261] Aspect 7: The method of any of aspects 5 through 6, wherein two or more neighboring base stations have different predetermined time offsets for interference randomization among neighboring base stations.

[0262] Aspect 8: The method of any of aspects 4 through 7, wherein the set of periodic wireless resources has a same periodicity as the periodicity of the synchronization signal blocks, or has a periodicity that is a multiple or factor of the periodicity of the synchronization signal blocks.

[0263] Aspect 9: The method of any of aspects 3 through 8, wherein the configuration information is received in radio resource control signaling from the base station that indicates a periodicity associated with the set of periodic wireless resources.

[0264] Aspect 10: The method of aspect 9, wherein the radio resource control signaling includes an indication of one or more of a starting set of resources for the set of periodic wireless resources, a periodicity of the set of periodic wireless resources, an offset from the starting set of resources, or any combinations thereof.

[0265] Aspect 11 : The method of any of aspects 1 through 10, further comprising: communicating with one or more of the base station or the second UE using a first radio frequency (RF) sub-system that is compliant with a wireless communications standard for data communications between UEs, and wherein the first waveform is transmitted and the second waveform is received using a second RF sub-system that is noncompliant with the wireless communications standard.

[0266] Aspect 12: The method of any of aspects 1 through 11, further comprising: transmitting, responsive to detecting the second waveform, a third waveform for positioning or ranging procedures for use at the second UE.

[0267] Aspect 13: The method of aspect 12, wherein the first waveform is transmitted at a first time, and the second waveform is received at the first UE at a second time that is after the first time, and the third waveform is transmitted at a third time that is a predetermined offset from the second time, and the second waveform is transmitted following a predetermined offset from a time of receipt of the first waveform at the second UE.

[0268] Aspect 14: The method of any of aspects 12 through 13, wherein the position of the first UE or ranging information of the distance between the first UE and the second UE is estimated at the first UE based at least in part on a time difference between transmitting the first waveform and receiving the second waveform and a speed at which the first waveform propagates between the first UE and the second UE. [0269] Aspect 15: The method of any of aspects 1 through 14, wherein the position of the first UE or ranging information of the distance between the first UE and the second UE is estimated based at least in part on information indicated by the second waveform.

[0270] Aspect 16: The method of aspect 15, wherein a plurality of waveforms are available for use in determining one or more of positioning or ranging information that are each mapped to a different combination of speed and direction of a transmitting UE, and the information indicated by the first waveform includes a first combination of speed and direction associated with the second UE that is mapped to the first waveform.

[0271] Aspect 17: The method of any of aspects 1 through 16, wherein each of the first waveform and the second waveform are analog domain waveforms that are processed in analog components of the first UE.

[0272] Aspect 18: The method of any of aspects 1 through 17, wherein the indication of one or more of the position of the first UE or the ranging information, and the indication of the updated position or updated ranging information, are communicated in one or more of a medium access control (MAC) control element (CE), in control channel communications, in shared channel communications, or any combinations thereof.

[0273] Aspect 19: A method for wireless communication at a first UE, comprising: detecting one or more instance of a second positioning signal from a second UE; determining, at a machine learning algorithm at the first UE, a first estimate of one or more of a position of the first UE or ranging information of a distance between the first UE and the second UE based at least in part on the second positioning signal; transmitting the first estimate to a base station; receiving, from the base station, an updated estimate of one or more of the position of the first UE or ranging information associated with the second UE; and updating the machine learning algorithm based at least in part on the updated estimate.

[0274] Aspect 20: The method of aspect 19, wherein the second positioning signal from the second UE comprises a predetermined waveform transmitted in a set of periodic wireless resources.

[0275] Aspect 21 : The method of any of aspects 19 through 20, further comprising: receiving, from the base station, configuration information that indicates one or more waveforms for the second positioning signal, a periodicity of positioning signal transmissions, or any combinations thereof.

[0276] Aspect 22: The method of any of aspects 19 through 21, further comprising: transmitting, prior to receiving the second positioning signal from the second UE, a first positioning signal to at least the second UE, and wherein the updated estimate received from the base station is based on a plurality of positioning estimates received from a plurality of UEs.

[0277] Aspect 23: The method of any of aspects 19 through 22, further comprising: transmitting, responsive to receiving the second positioning signal from the second UE, a third positioning signal to at least the second UE, and wherein the updated estimate received from the base station is based at least in part on the first estimate transmitted by the first UE and a second estimate from the second UE that is based at least in part on the third positioning signal.

[0278] Aspect 24: The method of any of aspects 19 through 23, further comprising: transmitting, responsive to detecting the second positioning signal, a third positioning signal for positioning or ranging procedures at the second UE, wherein the second positioning signal is transmitted at a first time and received at the first UE at a first time differential after the first time, and wherein the third positioning signal is transmitted at a second time that is a predetermined offset from the first time plus the first time differential.

[0279] Aspect 25: The method of aspect 24, wherein the position of the first UE or ranging information of the distance between the first UE and the second UE is estimated at the first UE based at least in part on the first time differential and a speed at which the second positioning signal propagates between the first UE and the second UE, and the predetermined offset is associated with a processing time for detecting a first positioning signal transmitted by the first UE.

[0280] Aspect 26: A method for wireless communication at a base station, comprising: configuring a set of periodic wireless resources for transmission of one or more predetermined waveforms between at least a first UE and a second UE; receiving, from the first UE, a first position estimate that is based at least in part on a first waveform of the one or more predetermined waveforms that is detected at the first UE and transmitted by the second UE; receiving, from the second UE, a second position estimate that is based at least in part on a second waveform of the one or more predetermined waveforms that is detected at the second UE and transmitted by the first UE or a third UE; determining a first updated position estimate for the first UE based at least in part on the first position estimate and the second position estimate; and transmitting the first updated position estimate to the first UE.

[0281] Aspect 27: The method of aspect 26, wherein the determining comprises: generating, using a closed-loop machine-learning algorithm, the first updated position estimate of the first UE based at least in part on the first position estimate and the second position estimate, wherein the closed-loop machine-learning algorithm is updated based on one or more subsequent position estimates from the first UE and the second UE.

[0282] Aspect 28: The method of any of aspects 26 through 27, further comprising: transmitting, to each of the first UE and the second UE, configuration information that indicates the one or more predetermined waveforms and a periodicity of the set of periodic wireless resources.

[0283] Aspect 29: The method of aspect 28, wherein the periodicity of the set of periodic wireless resources corresponds to a periodicity of synchronization signal blocks transmitted by the base station.

[0284] Aspect 30: The method of aspect 29, wherein the set of periodic wireless resources includes wireless resources having a predetermined time offset from the synchronization signal blocks.

[0285] Aspect 31 : The method of aspect 30, wherein the predetermined time offset is derived based at least in part on a cell identification of the base station, a system bandwidth for communications with the base station, or any combinations thereof.

[0286] Aspect 32: The method of any of aspects 30 through 31, wherein two or more neighboring base stations have different predetermined time offsets for interference randomization among neighboring base stations.

[0287] Aspect 33: The method of any of aspects 29 through 32, wherein the set of periodic wireless resources has a same periodicity as the periodicity of the synchronization signal blocks, or has a periodicity that is a multiple or factor of the periodicity of the synchronization signal blocks. [0288] Aspect 34: The method of any of aspects 28 through 33, wherein the configuration information is transmitted in radio resource control signaling that indicates the periodicity associated with the set of periodic wireless resources.

[0289] Aspect 35: The method of aspect 34, wherein the radio resource control signaling includes an indication of one or more of a starting set of resources for the set of periodic wireless resources, the periodicity of the set of periodic wireless resources, an offset from the starting set of resources, or any combinations thereof.

[0290] Aspect 36: The method of any of aspects 26 through 35, wherein the second position estimate of the second UE is responsive to the first UE transmitting the second waveform, the first waveform is transmitted at a first time and received at the first UE at a first time differential after the first time, and the second waveform is transmitted at a second time that is a predetermined offset from the first time plus the first time differential.

[0291] Aspect 37: The method of any of aspects 26 through 36, further comprising: configuring a plurality of predetermined waveforms for transmission by at least the first UE and the second UE using the set of periodic wireless resources, wherein each predetermined waveform of the plurality of predetermined waveforms indicates information usable for position estimation at a receiving UE.

[0292] Aspect 38: The method of aspect 37, wherein each of the plurality of predetermined waveforms are mapped to a different combination of speed and direction of a transmitting UE, and the information indicated by the first waveform includes a first combination of speed and direction associated with the second UE that is mapped to the first waveform.

[0293] Aspect 39: A method for wireless communication at a base station, comprising: receiving, from a first UE, a first position estimate that is based at least in part on a first positioning signal that is transmitted by a second UE and is detected at the first UE; receiving, from the second UE, a second position estimate that is based at least in part on a second positioning signal that is transmitted by the first UE or a third UE and is detected at the second UE; determining, at a machine learning algorithm at the base station, a first updated position estimate for the first UE based at least in part on the first position estimate and the second position estimate, and a second updated position estimate for the second UE based at least in part on the first position estimate and the second position estimate; transmitting the first updated position estimate to the first UE and the second updated position estimate to the second UE; and updating the machine learning algorithm based at least in part on one or more subsequent position estimates received from the first UE or the second UE.

[0294] Aspect 40: The method of aspect 39, further comprising: configuring a set of periodic wireless resources for transmission of positioning signals, wherein the positioning signals comprise one or more predetermined waveforms for transmission in the set of periodic wireless resources.

[0295] Aspect 41 : The method of aspect 40, further comprising: transmitting, to the first UE and the second UE, configuration information that indicates the one or more predetermined waveforms, a periodicity of positioning signal transmissions, or any combinations thereof.

[0296] Aspect 42: The method of aspect 41, wherein the configuration information is transmitted in radio resource control signaling that indicates the periodicity associated with the set of periodic wireless resources.

[0297] Aspect 43 : The method of aspect 42, wherein the radio resource control signaling includes an indication of one or more of a starting set of resources for the set of periodic wireless resources, the periodicity of the set of periodic wireless resources, an offset from the starting set of resources, or any combinations thereof.

[0298] Aspect 44: An apparatus for wireless communication at a first UE, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of aspects 1 through 18.

[0299] Aspect 45: An apparatus for wireless communication at a first UE, comprising at least one means for performing a method of any of aspects 1 through 18.

[0300] Aspect 46: A non-transitory computer-readable medium storing code for wireless communication at a first UE, the code comprising instructions executable by a processor to perform a method of any of aspects 1 through 18.

[0301] Aspect 47: An apparatus for wireless communication at a first UE, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of aspects 19 through 25.

[0302] Aspect 48: An apparatus for wireless communication at a first UE, comprising at least one means for performing a method of any of aspects 19 through 25. [0303] Aspect 49: A non-transitory computer-readable medium storing code for wireless communication at a first UE, the code comprising instructions executable by a processor to perform a method of any of aspects 19 through 25.

[0304] Aspect 50: An apparatus for wireless communication at a base station, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of aspects 26 through 38.

[0305] Aspect 51 : An apparatus for wireless communication at a base station, comprising at least one means for performing a method of any of aspects 26 through 38.

[0306] Aspect 52: A non-transitory computer-readable medium storing code for wireless communication at a base station, the code comprising instructions executable by a processor to perform a method of any of aspects 26 through 38.

[0307] Aspect 53 : An apparatus for wireless communication at a base station, comprising a processor; memory coupled with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of aspects 39 through 43.

[0308] Aspect 54: An apparatus for wireless communication at a base station, comprising at least one means for performing a method of any of aspects 39 through 43.

[0309] Aspect 55: A non-transitory computer-readable medium storing code for wireless communication at a base station, the code comprising instructions executable by a processor to perform a method of any of aspects 39 through 43.

[0310] Although aspects of an LTE, LTE-A, LTE-A Pro, or NR system may be described for purposes of example, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applicable to various other wireless communications systems such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, as well as other systems and radio technologies not explicitly mentioned herein.

[0311] Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0312] The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0313] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.

[0314] Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include random- access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

[0315] As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of’ or “one or more of’) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on.”

[0316] In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label, or other subsequent reference label. [0317] The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “example” used herein means “serving as an example, instance, or illustration,” and not “preferred” or “advantageous over other examples.” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples. [0318] The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein, but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.