BACKGROUND

[0001] Wireless systems typically include multiple User Equipment (UE) devices communicatively coupled to one or more Base Stations (BS). The one or more BSs may be Long Term Evolved (LTE) evolved NodeBs (eNB) or new radio (NR) NodeBs (gNB) or next generation node Bs (gNB) that can be communicatively coupled to one or more UEs by a Third-Generation Partnership Project (3GPP) network.

[0002] Next generation wireless communication systems are expected to be a unified network/system that is targeted to meet vastly different and sometimes conflicting performance dimensions and services. New Radio Access Technology (RAT) is expected to support a broad range of use cases including Enhanced Mobile Broadband (eMBB), Massive Machine Type Communication (mMTC), Mission Critical Machine Type Communication (uMTC), and similar service types operating in frequency ranges up to 100 GHz. In a TDD new radio (NR) system, a next generation node B (gNB) can dynamically determine whether a selected subframe is a downlink (DL) subframe or an uplink (UL) subframe. In such a system, the neighboring cells can have DL and UL subframes that are time-aligned. This can result in cross-link interference between DL and UL transmissions.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Features and advantages of the disclosure will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the disclosure; and, wherein:

[0004] FIG. 1 illustrates crosslink interference in a dynamic time division duplex (TDD) new radio (NR) system in accordance with an example;

[0005] FIG. 2 illustrates interference measurement reference signal (IM-RS) time aligned in downlink and uplink and resource aligned with the corresponding data in accordance with an example; [0006] FIG. 3 illustrates an example of the comb structure in accordance with an example;

[0007] FIG. 4 depicts functionality of a next generation node B (gNB) operable to measure crosslink signal-to-interference ratio (SINR) in a dynamic time division duplex (TDD) new radio (NR) system in accordance with an example;

[0008] FIG. 5 depicts functionality of a user equipment (UE) operable to measure crosslink signal-to-interference ratio (SINR) in a dynamic time division duplex (TDD) new radio (NR) system in accordance with an example;

[0009] FIG. 6 depicts a flowchart of a machine readable storage medium having instructions embodied thereon for measuring crosslink signal-to-interference ratio (SINR) in a dynamic time division duplex (TDD) new radio (NR) system in accordance with an example;

[0010] FIG. 7 illustrates an architecture of a wireless network in accordance with an example;

[0011] FIG. 8 illustrates a diagram of a wireless device (e.g., UE) in accordance with an example;

[0012] FIG. 9 illustrates interfaces of baseband circuitry in accordance with an example; and

[0013] FIG. 10 illustrates a diagram of a wireless device (e.g., UE) in accordance with an example.

[0014] Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the technology is thereby intended. DETAILED DESCRIPTION

[0015] Before the present technology is disclosed and described, it is to be understood that this technology is not limited to the particular structures, process actions, or materials disclosed herein, but is extended to equivalents thereof as would be recognized by those ordinarily skilled in the relevant arts. It should also be understood that terminology employed herein is used for the purpose of describing particular examples only and is not intended to be limiting. The same reference numerals in different drawings represent the same element. Numbers provided in flow charts and processes are provided for clarity in illustrating actions and operations and do not necessarily indicate a particular order or sequence.

EXAMPLE EMBODIMENTS

[0016] An initial overview of technology embodiments is provided below and then specific technology embodiments are described in further detail later. This initial summary is intended to aid readers in understanding the technology more quickly but is not intended to identify key features or essential features of the technology nor is it intended to limit the scope of the claimed subject matter.

[0017] In a wireless cellular communication system that is configured to transmit using frequency division duplex (FDD), base stations operating in two adjacent cells can transmit at the same frequency. For example, a user equipment (UE) that is receiving a DL from a cell can also receive interference from a DL signal transmitted by a base station in an adjacent cell. In another example, a base station (BS) that is receiving an UL signal from a UE can also receive interference from a UE transmitting an UL signal in an adjacent cell. These two types of interference can be predicted; therefore, the BS can manage this interference and predict it based on past observations.

[0018] In a wireless cellular communication system configured to operate using time division duplex (TDD), a base station, such as a next generation node B (gNB), can dynamically determine whether a selected subframe is a downlink (DL) subframe or an uplink (UL) subframe. In such a system, the neighboring cells can have DL and UL subframes that are time-aligned. This can result in cross-link interference between DL and UL transmissions.

[0019] In one example, as illustrated in FIG. 1, crosslink interference can result from two types of crosslink interference. In one type of crosslink interference, a gNB 110 can transmit DL data to a UE 130. This can cause crosslink interference from the gNB 110 to gNB 120. This crosslink interference can interfere with the ability of the gNB 120 to receive UL data from a UE 140. This crosslink interference can result from neighboring cells having a different transmission direction in a time slot. In the preceding example, gNB 110 transmits in a DL time slot and gNB 120 receives in an UL time slot. This crosslink interference from gNB 110 to gNB 120 can occur when the slots for gNB 110 and gNB 120 are substantially time aligned such that there it causes interference.

[0020] In another type of crosslink interference, a UE 140 can transmit UL data to a gNB 120. This can cause crosslink interference from the UE 140 to a UE 130. This crosslink interference can interfere with the ability of the UE 130 to receive DL data from a gNB 110. This crosslink interference can result from neighboring cells having a different transmission direction in a time slot. In the preceding example, UE 140 transmits in an UL time slot and UE 130 receives in a DL time slot. The crosslink interference from UE 140 to UE 130 can occur when the slots for gNB 140 and UE 130 are substantially time aligned such that it causes interference.

[0021] These two types of crosslink interference in a dynamic TDD system can be difficult to predict based on past observations. To mitigate the crosslink interference, it is useful to be able to accurately measure the amount of interference received at a gNB from another gNB transmitting in an adjacent cell and the amount of interference received at a UE from another UE transmitting in an adjacent cell. Accurate measurements of these two types of interference can be important in determining appropriate link adaptation in both the DL and UL directions for data transmission.

[0022] A channel state information reference signal (CSI-RS) is a reference signal that is transmitted by a base station in the DL direction and received at a UE. The CSI-RS can be used by the UE to estimate the channel quality and report channel quality information (CQI) to the base station. A sounding reference signal (SRS) is a reference signal that can be transmitted by a UE in the UL direction and can be used by the base station, such as a gNB, to estimate the uplink channel quality. In one example, these two reference signals, the CSI-RS and the SRS, can be time-aligned to enable accurate measurement of crosslink interference in both the UL and DL directions in a dynamic TDD new radio (NR) system. Time-aligning the CSI-RS and the SRS can reduce signaling overhead because each cell may not be configured to determine whether the adjacent cell is transmitting or receiving. This can result in a unified design. The dynamic TDD NR system is not limited to the CSI-RS and the SRS. Other types of references signals can also be used, including interference measurement reference signals (IM-RS), which is a reference signal that can be used to measure interference.

[0023] In one example, the reference signals can be aligned by time aligning the CSI-RS from gNB 110 and the SRS UE 140. For example, an interleaved frequency division multiple access (IFDMA) comb structure can be used for both the CSI-RS and SRS to measure the cross-link interference. A frequency domain decimation factor used to define the comb structure for the CSI-RS can be an integer multiple of the decimation factor used to define the comb structure for the SRS. For example, if the SRS supports 2 combs with a frequency decimation factor of 2, the CSI-RS can support 12 combs with a frequency decimation factor of 12. In this example, the frequency domain decimation factor of 12 for the CSI-RS is an integer multiple of the frequency domain decimation factor of 2 for the SRS.

[0024] In another example, the transmission of the CSI-RS and the SRS can be precoded or non-precoded. When the CSI-RS is precoded, the CSI-RS can undergo spatial processing. For example, the same signal can be transmitted from each of the transmit antennas of a single node and weighted with a specific phase and gain so that the signal power can be maximized at the receiver output. When the CSI-RS is non-precoded, the signal might not undergo spatial processing. When the SRS is precoded, the SRS can undergo spatial processing. For example, the same signal can be transmitted from each of the transmitter antennas and weighted with a specific phase and gain so that the signal power can be maximized at the receiver output. When the SRS is non-precoded, the SRS might not undergo spatial processing. When the receiver measures the crosslink interference, the receiver can measure the interference level and the precoding metrics.

[0025] In one example, to be able to measure the crosslink interference, the gNB 110 can configure a zero power CSI-RS resource for UE 130 on a comb of the configured CSI-RS resource. This resource can be an interference measurement resource for the crosslink interference on the DL of gNB 110 from the UL transmission from UE 140. This configuration of the zero power CSI-RS resource can be done dynamically using physical downlink control channel (PDCCH) or via higher layer signaling, such as radio resource control (RRC) signaling.

[0026] In another example, gNB 120 can configure a zero power SRS resource for UE 140 on a comb of the configured SRS resource. This resource can be an interference measurement resource for the crosslink interference on the UL of UE 140 and from the DL transmission from gNB 110. This configuration of the zero power CSI-RS resource can be done dynamically using physical downlink control channel (PDCCH) or via higher layer signaling, such as radio resource control (RRC) signaling.

[0027] In another example, multiple UEs performing UL transmission in adjacent cells can cause crosslink interference on the gNB 110 transmitting on the DL to the UE 130. The crosslink interference from the multiple UEs performing UL transmission in adjacent cells can be measured by using the orthogonal separation in the SRS transmissions of the multiple UEs using either frequency division multiplexing (FDM) or time-domain cyclic shifts.

[0028] In another example, FIG. 2 illustrates a basic subframe structure of a dynamic TDD NR system. In this example, cell 1 and cell 2 can be time aligned and resource aligned. The box 202 for cell 1 and the box 212 for cell 2 can identify a channel that is transmitted from the gNB and can include resource scheduling by the BS or gNB. The direction of transmission for box 202 and box 212 is DL and can include resource blocks (RB) ranging from n to n+k, in which n is the index of an RB, k is the number of RBs that are transmitted, and n and k are positive integers.

[0029] Box 204 and box 214 can identify a channel that is transmitted from a transmitter side of a corresponding data transmission and can include a measurement signal transmission by the transmitter side. The direction of transmission for box 204 and box 214 is DL or UL and can include resource blocks (RB) ranging from n to n+k in which k is the number of RBs that are transmitted.

[0030] Box 206 and 216 can identify a channel that is transmitted from a receiver side of a corresponding data transmission and includes measurement report by the receiver side. The direction of transmission for box 206 and box 216 is UL or DL and can include resource blocks (RB) ranging from n to n+k in which k is the number of RBs that are transmitted.

[0031] Box 208 and 218 can identify traffic data transmission by the transmitter. The direction of transmission for box 208 and box 218 is DL or UL and can include resource blocks (RB) ranging from n to n+k in which k is the number of RBs that are transmitted. [0032] Limiting interference measurement within the scheduled resource blocks can ensure accurate interference measurement because the interference measurement setup can emulate the same interference environment as the corresponding data transmission.

[0033] By time aligning and resource aligning the interference measurement reference signals (IM-RS), accurate cross-interference measurement can be achieved. The IM-RS can include CSI-RS, SRS reference signals, and other related reference signals that can be used for interference measurement. The IM-RS for the DL and the UL can be jointly optimized to achieve good cross-link interference measurement accuracy. To obtain low cross-correlation on the IM-RS among cells and to contain peak-to-average power ratio (PAPR) in the UL, a comb structure IM-RS can be used for cross-link interference measurement.

[0034] In one example, as illustrated in FIG. 3, the carrier bandwidth can be divided into several combs as in IFDMA. The frequency domain decimation factor can be an integer greater than 1, and, as illustrated in FIG. 3, can be 2. With two interleaved combs 300, cells 1 and 2 can use one comb for IM-RS and cells 3 and 4 can use the other comb for IM-RS. In this example, cells 1 and 2 can use the shaded boxes for IM-RS and cells 3 and 4 can use the remaining boxes for IM-RS. The IM-RS can be non-zero power (NZP) CSI-RS in the DL and NZP SRS in the UL. Alternatively, the IM-RS can be a reference signal of the same type in both the DL and the UL. Each comb can comprise a plurality of subcarriers that are interleaved with subcarriers of other combs in the number of combs.

[0035] Same or different sequences can be used for NZP CSI-RS and NZP SRS.

Examples of the sequences for reference signals that can be used include pseudo-noise (PN) sequences, Zadoff-Chu (ZC) sequences, and Golay sequences. A pseudo-noise sequence or pseudo-random noise sequence can be a sequence that is similar to a random sequence of bits but is deterministically generated. A Zadoff-Chu sequence can be a sequence that can give rise to a signal of constant amplitude, wherein cyclically shifted versions of the sequence on a signal result in zero correlation with one another at the receiver. This can result in the useful property that the cyclically shifted versions of the sequence are orthogonal to each other. A Golay sequence can be two binary sequences with the property that their out-of-phase aperiodic autocorrelation coefficients sum to zero. Each cell can be assigned one base sequence or multiple base sequences. Different base sequences can be used by different cells.

[0036] The downlink IM-RS can be non-precoded or precoded. The uplink IM-RS can be non-precoded or precoded. When the IM-RS is precoded, the IM-RS can undergo spatial processing. For example, the same signal can be transmitted from each of the transmit antennas and weighted with a specific phase and gain so that the signal power can be maximized at the receiver output. When the IM-RS is non-precoded, the signal might not undergo spatial processing. When the receiver measures the crosslink interference, it can measure the interference level and the precoding metrics.

[0037] The downlink IM-RS can be encoded via physical layer signaling, such as the physical downlink control channel (PDCCH), or via higher layer signaling, such as RRC signaling. The uplink IM-RS can be encoded via physical layer signaling, such as the physical downlink control channel (PDCCH), or via higher layer signaling, such as RRC signaling.

[0038] Time-domain cyclic shift can be applied across different antenna ports in the DL and the UL. For example, when ZC sequences are utilized, the cyclically shifted versions of the sequence can be applied across different antenna ports in the DL and the UL. This can result in the property that each of the antenna ports can transmit or receive orthogonally from each other.

[0039] The IM-RS among cells can be multiplexed by FDM or by code-division multiplexing (CDM). When the IM-RS among cells is multiplexed by FDM, different combs can be used for each cell. When the IM-RS among cells is multiplexed by CDM, different base sequences and different time domain cyclic shifts of a sequence can be used for each cell.

[0040] When measuring crosslink interference, the terminal (BS or UE) can measure the interference level from its selected comb and other combs. The overall interference level can be calculated from the measurement of the interference level of the selected comb and the other combs. For example, if the number of combs is 4, then the terminal can measure the interference level of its own comb, which can be comb A, and the interference level of the other combs, which can be combs B, C, and D. In this example, the crosslink interference can be the sum of the interference levels of combs A, B, C, and D.

[0041] In another example, the interference measurement resources (IMR) can be configured at the UE using one or more of the following parameters. The number of combs can be set as n combs in which the interference measurement resources are located every n subcarriers in a selected orthogonal frequency division multiplexing (OFDM) symbol. For example, n can be a positive integer greater than 1 and a multiple of 2, such as 2, 4, 8, 12, and so forth. For example, if n is equal to 2, then the number of combs can be set to be 2 and the interference measurement resources can be located every 2 subcarriers in a selected OFDM symbol.

[0042] In another example, the comb frequency offset can also be configured at the UE. This can identify the initial resource element (RE) in the physical resource blocks (PRB) for the IMR. This can be a positive integer that is greater than or equal to 0 and less than n, the number of combs. For example, if the number of combs is 4, the comb frequency offset can be configured to be 3. In this example, the initial RE in the PRB for the IMR would be 3.

[0043] In another example, the resource allocation in the frequency domain for IMR transmission can also be configured at the UE. This can identify the indices of valid PRBs for interference measurements. A valid PRB, in this example, can be the PRB that is used for interference measurements.

[0044] The subframe indices for IMR transmission can also be configured at the UE. This can identify the subframe where the UE can transmit the IM-RS. The IM-RS sequence can also be the subframe specified.

[0045] When the IMR parameters have been configured at the UE, the UE can perform interference measurements for the indicated IMR resource elements and use the measured interference for channel state information (CSI). The IMR resource elements can collide with other reference signals configured at the UE, such as NZP CSI-RS. In this example, the IMR or the corresponding colliding reference signal configuration can include an additional parameter. This additional parameter can indicate whether the contribution from the reference signal should be excluded or compensated prior to interference measurement. [0046] In another example, the zero-power (ZP) CSI-RS can also include a comb structure that indicates physical downlink or uplink resource element mapping. This ZP CSI-RS can be configured by the following parameters. The number of combs can be set as n combs in which the interference measurement resources are located every n subcarriers in a selected orthogonal frequency division multiplexing (OFDM) symbol. For example, n can be a positive integer greater than 1 and a multiple of 2, such as 2, 4, 8, 12, and so forth. For example, if n is equal to 2, then the number of combs can be set to be 2 and the interference measurement resources can be located every 2 subcarriers in a selected OFDM symbol.

[0047] In another example, the comb frequency offset can also be configured at the UE. This can identify the initial resource element (RE) in the physical resource blocks (PRB) for the IMR. This can be a positive integer that is greater than or equal to 0 and less than n, the number of combs. For example, if the number of combs is 4, the comb frequency offset can be configured to be 3. In this example, the initial RE in the PRB for the IMR will be 3.

[0048] The subframe indices for IMR transmission can also be configured at the UE. This can identify the subframe where the UE can transmit the IM-RS. The IM-RS sequence can also be the subframe specified.

[0049] When the ZP CSI-RS parameters have been configured at the UE, the UE can perform physical data channel resource element mapping around the ZP CSI-RS resource elements. Different configurations of ZP CSI-RS can be used for DL and UL.

[0050] There are at least three different ways in which crosslink interference can be measured. First, the signals can be time-aligned and all of the interference can be measured. Second, the signals can be differentiated as long as the UE knows the resource and signals used by the source are orthogonal. Third, zero power can be used in some of the interfering cells. In other words, the cells can be muted to measure the interference without the contributions from those cells. Crosslink interference can be measured by measuring the crosslink signal-to-interference ratio (SINR).

[0051] Another example provides functionality 400 of a first next generation node B (gNB) operable to measure crosslink signal-to-interference ratio (SINR) in a dynamic time division duplex (TDD) new radio (NR) system relative to a second gNB, as shown in FIG. 4. The gNB can comprise one or more processors. The one or more processors can be configured to encode, at the first gNB, a downlink interference measurement reference signal (IM-RS), for transmission to a first user equipment (UE), in a selected comb of an IFDMA comb structure having n combs, wherein n is a positive integer, as in block 410. The one or more processors can be configured to decode, at the first gNB, an uplink IM- RS from a second UE received in one of the n combs in the IFDMA comb structure, wherein the uplink IM-RS is time aligned with the downlink IM-RS, as in block 420. The one or more processors can be configured to determine, at the first gNB, the crosslink interference in the IFDMA comb structure, caused by one or more of the second gNB and the second UE, based on the downlink IM-RS and the uplink IM-RS, as in block 430. In addition, the gNB can comprise a memory interface configured to receive from a memory the downlink IM-RS.

[0052] Another example provides functionality 500 of a first user equipment (UE) operable to measure crosslink signal-to-interference ratio (SINR) in a dynamic time division duplex (TDD) new radio (NR) system relative to a second UE, as shown in FIG. 5. The gNB can comprise one or more processors. The one or more processors can be configured to encode, at the first UE, an uplink interference measurement reference signal (IM-RS), for transmission to a first next generation node B (gNB), in a selected comb of an IFDMA comb structure having n combs, wherein n is a positive integer, as in block 510. The one or more processors can be configured to decode, at the first UE, a downlink IM-RS from a second gNB received in one of the n combs in the IFDMA comb structure, wherein the downlink IM-RS is time aligned with the uplink IM-RS, as in block 520. The one or more processors can be configured to determine, at the first UE, the crosslink interference in the IFDMA comb structure, caused by one or more of the second UE and the second gNB, based on the downlink IM-RS and the uplink IM-RS, as in block 530. In addition, the gNB can comprise a memory interface configured to receive from a memory the uplink IM-RS.

[0053] Another example provides at least one machine readable storage medium having instructions 600 embodied thereon for measuring crosslink signal-to-interference ratio (SINR) in a dynamic time division duplex (TDD) new radio (NR) system, as shown in FIG. 6. The instructions can be executed on a machine, where the instructions are included on at least one computer readable medium or one non-transitory machine readable storage medium. The instructions when executed perform: encoding, at the first gNB, a downlink interference measurement reference signal (IM-RS), for transmission to a first user equipment (UE), in a selected comb of an IFDMA comb structure having n combs, wherein n is a positive integer, as in block 610. The instructions when executed perform: decoding, at the first gNB, an uplink IM-RS from a second UE received in one of the n combs in the IFDMA comb structure, wherein the uplink IM-RS is time aligned with the downlink IM-RS, as in block 620. The instructions when executed perform: determining, at the first gNB, the crosslink interference in the IFDMA comb structure, caused by one or more of the second gNB and the second UE, based on the downlink IM- RS and the uplink IM-RS, as in block 630.

[0054] While examples have been provided in which an eNodeB has been specified, they are not intended to be limiting. A fifth generation gNB can be used in place of the eNodeB. Accordingly, unless otherwise stated, any example herein in which an eNodeB has been disclosed, can similarly be disclosed with the use of a gNB (Next Generation node B).

[0055] FIG. 7 illustrates an architecture of a system 700 of a network in accordance with some embodiments. The system 700 is shown to include a user equipment (UE) 701 and a UE 702. The UEs 701 and 702 are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks), but may also comprise any mobile or non-mobile computing device, such as Personal Data Assistants (PDAs), pagers, laptop computers, desktop computers, wireless handsets, or any computing device including a wireless communications interface.

[0056] In some embodiments, any of the UEs 701 and 702 can comprise an Internet of Things (IoT) UE, which can comprise a network access layer designed for low-power IoT applications utilizing short-lived UE connections. An IoT UE can utilize technologies such as machine-to-machine (M2M) or machine-type communications (MTC) for exchanging data with an MTC server or device via a public land mobile network

(PLMN), Proximity-Based Service (ProSe) or device-to-device (D2D) communication, sensor networks, or IoT networks. The M2M or MTC exchange of data may be a machine-initiated exchange of data. An IoT network describes interconnecting IoT UEs, which may include uniquely identifiable embedded computing devices (within the Internet infrastructure), with short-lived connections. The IoT UEs may execute background applications (e.g., keep-alive messages, status updates, etc.) to facilitate the connections of the IoT network.

[0057] The UEs 701 and 702 may be configured to connect, e.g., communicatively couple, with a radio access network (RAN) 710— the RAN 710 may be, for example, an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), a NextGen RAN (NG RAN), or some other type of RAN. The UEs 701 and 702 utilize connections 703 and 704, respectively, each of which comprises a physical communications interface or layer (discussed in further detail below); in this example, the connections 703 and 704 are illustrated as an air interface to enable communicative coupling, and can be consistent with cellular communications protocols, such as a Global System for Mobile Communications (GSM) protocol, a code-division multiple access (CDMA) network protocol, a Push-to-Talk (PTT) protocol, a PTT over Cellular (POC) protocol, a Universal Mobile Telecommunications System (UMTS) protocol, a 3GPP Long Term Evolution (LTE) protocol, a fifth generation (5G) protocol, a New Radio (NR) protocol, and the like.

[0058] In this embodiment, the UEs 701 and 702 may further directly exchange communication data via a ProSe interface 705. The ProSe interface 705 may alternatively be referred to as a sidelink interface comprising one or more logical channels, including but not limited to a Physical Sidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel (PSSCH), a Physical Sidelink Discovery Channel (PSDCH), and a Physical Sidelink Broadcast Channel (PSBCH).

[0059] The UE 702 is shown to be configured to access an access point (AP) 706 via connection 707. The connection 707 can comprise a local wireless connection, such as a connection consistent with any IEEE 802.15 protocol, wherein the AP 706 would comprise a wireless fidelity (WiFi®) router. In this example, the AP 706 is shown to be connected to the Internet without connecting to the core network of the wireless system (described in further detail below).

[0060] The RAN 710 can include one or more access nodes that enable the connections 703 and 704. These access nodes (ANs) can be referred to as base stations (BSs),

NodeBs, evolved NodeBs (eNBs), next Generation NodeBs (gNB), RAN nodes, and so forth, and can comprise ground stations (e.g., terrestrial access points) or satellite stations providing coverage within a geographic area (e.g., a cell). The RAN 710 may include one or more RAN nodes for providing macrocells, e.g., macro RAN node 711, and one or more RAN nodes for providing femtocells or picocells (e.g., cells having smaller coverage areas, smaller user capacity, or higher bandwidth compared to macrocells), e.g., low power (LP) RAN node 712.

[0061] Any of the RAN nodes 711 and 712 can terminate the air interface protocol and can be the first point of contact for the UEs 701 and 702. In some embodiments, any of the RAN nodes 711 and 712 can fulfill various logical functions for the RAN 710 including, but not limited to, radio network controller (RNC) functions such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management.

[0062] In accordance with some embodiments, the UEs 701 and 702 can be configured to communicate using Orthogonal Frequency -Division Multiplexing (OFDM)

communication signals with each other or with any of the RAN nodes 711 and 712 over a multicarrier communication channel in accordance various communication techniques, such as, but not limited to, an Orthogonal Frequency -Division Multiple Access (OFDMA) communication technique (e.g., for downlink communications) or a Single Carrier Frequency Division Multiple Access (SC-FDMA) communication technique (e.g., for uplink and ProSe or sidelink communications), although the scope of the embodiments is not limited in this respect. The OFDM signals can comprise a plurality of orthogonal subcarriers.

[0063] In some embodiments, a downlink resource grid can be used for downlink transmissions from any of the RAN nodes 711 and 712 to the UEs 701 and 702, while uplink transmissions can utilize similar techniques. The grid can be a time-frequency grid, called a resource grid or time-frequency resource grid, which is the physical resource in the downlink in each slot. Such a time-frequency plane representation is a common practice for OFDM systems, which makes it intuitive for radio resource allocation. Each column and each row of the resource grid corresponds to one OFDM symbol and one OFDM subcarrier, respectively. The duration of the resource grid in the time domain corresponds to one slot in a radio frame. The smallest time-frequency unit in a resource grid is denoted as a resource element. Each resource grid comprises a number of resource blocks, which describe the mapping of certain physical channels to resource elements. Each resource block comprises a collection of resource elements; in the frequency domain, this may represent the smallest quantity of resources that currently can be allocated. There are several different physical downlink channels that are conveyed using such resource blocks.

[0064] The physical downlink shared channel (PDSCH) may carry user data and higher- layer signaling to the UEs 701 and 702. The physical downlink control channel

(PDCCH) may carry information about the transport format and resource allocations related to the PDSCH channel, among other things. It may also inform the UEs 701 and 702 about the transport format, resource allocation, and H-ARQ (Hybrid Automatic Repeat Request) information related to the uplink shared channel. Typically, downlink scheduling (assigning control and shared channel resource blocks to the UE 702 within a cell) may be performed at any of the RAN nodes 711 and 712 based on channel quality information fed back from any of the UEs 701 and 702. The downlink resource assignment information may be sent on the PDCCH used for (e.g., assigned to) each of the UEs 701 and 702.

[0065] The PDCCH may use control channel elements (CCEs) to convey the control information. Before being mapped to resource elements, the PDCCH complex-valued symbols may first be organized into quadruplets, which may then be permuted using a sub-block interleaver for rate matching. Each PDCCH may be transmitted using one or more of these CCEs, where each CCE may correspond to nine sets of four physical resource elements known as resource element groups (REGs). Four Quadrature Phase Shift Keying (QPSK) symbols may be mapped to each REG. The PDCCH can be transmitted using one or more CCEs, depending on the size of the downlink control information (DCI) and the channel condition. There can be four or more different PDCCH formats defined in LTE with different numbers of CCEs (e.g., aggregation level, L=l, 2, 4, or 8).

[0066] Some embodiments may use concepts for resource allocation for control channel information that are an extension of the above-described concepts. For example, some embodiments may utilize an enhanced physical downlink control channel (EPDCCH) that uses PDSCH resources for control information transmission. The EPDCCH may be transmitted using one or more enhanced the control channel elements (ECCEs). Similar to above, each ECCE may correspond to nine sets of four physical resource elements known as an enhanced resource element groups (EREGs). An ECCE may have other numbers of EREGs in some situations.

[0067] The RAN 710 is shown to be communicatively coupled to a core network (CN) 720— via an SI interface 713. In embodiments, the CN 720 may be an evolved packet core (EPC) network, a NextGen Packet Core (NPC) network, or some other type of CN. In this embodiment the SI interface 713 is split into two parts: the SI -U interface 714, which carries traffic data between the RAN nodes 711 and 712 and the serving gateway (S-GW) 722, and the S I -mobility management entity (MME) interface 715, which is a signaling interface between the RAN nodes 711 and 712 and MMEs 721.

[0068] In this embodiment, the CN 720 comprises the MMEs 721, the S-GW 722, the Packet Data Network (PDN) Gateway (P-GW) 723, and a home subscriber server (HSS) 724. The MMEs 721 may be similar in function to the control plane of legacy Serving General Packet Radio Service (GPRS) Support Nodes (SGSN). The MMEs 721 may manage mobility aspects in access such as gateway selection and tracking area list management. The HSS 724 may comprise a database for network users, including subscription-related information to support the network entities' handling of

communication sessions. The CN 720 may comprise one or several HSSs 724, depending on the number of mobile subscribers, on the capacity of the equipment, on the organization of the network, etc. For example, the HSS 724 can provide support for routing/roaming, authentication, authorization, naming/addressing resolution, location dependencies, etc.

[0069] The S-GW 722 may terminate the SI interface 713 towards the RAN 710, and routes data packets between the RAN 710 and the CN 720. In addition, the S-GW 722 may be a local mobility anchor point for inter-RAN node handovers and also may provide an anchor for inter-3GPP mobility. Other responsibilities may include lawful intercept, charging, and some policy enforcement.

[0070] The P-GW 723 may terminate an SGi interface toward a PDN. The P-GW 723 may route data packets between the EPC network 723 and external networks such as a network including the application server 730 (alternatively referred to as application function (AF)) via an Internet Protocol (IP) interface 725. Generally, the application server 730 may be an element offering applications that use IP bearer resources with the core network (e.g., UMTS Packet Services (PS) domain, LTE PS data services, etc.). In this embodiment, the P-GW 723 is shown to be communicatively coupled to an application server 730 via an IP communications interface 725. The application server 730 can also be configured to support one or more communication services (e.g., Voice- over-Internet Protocol (VoIP) sessions, PTT sessions, group communication sessions, social networking services, etc.) for the UEs 701 and 702 via the CN 720.

[0071] The P-GW 723 may further be a node for policy enforcement and charging data collection. Policy and Charging Enforcement Function (PCRF) 726 is the policy and charging control element of the CN 720. In a non-roaming scenario, there may be a single PCRF in the Home Public Land Mobile Network (HPLMN) associated with a UE's Internet Protocol Connectivity Access Network (IP-CAN) session. In a roaming scenario with local breakout of traffic, there may be two PCRFs associated with a UE's IP-CAN session: a Home PCRF (H-PCRF) within a HPLMN and a Visited PCRF (V-PCRF) within a Visited Public Land Mobile Network (VPLMN). The PCRF 726 may be communicatively coupled to the application server 730 via the P-GW 723. The application server 730 may signal the PCRF 726 to indicate a new service flow and select the appropriate Quality of Service (QoS) and charging parameters. The PCRF 726 may provision this rule into a Policy and Charging Enforcement Function (PCEF) (not shown) with the appropriate traffic flow template (TFT) and QoS class of identifier (QCI), which commences the QoS and charging as specified by the application server 730.

[0072] FIG. 8 illustrates example components of a device 800 in accordance with some embodiments. In some embodiments, the device 800 may include application circuitry 802, baseband circuitry 804, Radio Frequency (RF) circuitry 806, front-end module (FEM) circuitry 808, one or more antennas 810, and power management circuitry (PMC) 812 coupled together at least as shown. The components of the illustrated device 800 may be included in a UE or a RAN node. In some embodiments, the device 800 may include less elements (e.g., a RAN node may not utilize application circuitry 802, and instead include a processor/controller to process IP data received from an EPC). In some embodiments, the device 800 may include additional elements such as, for example, memory /storage, display, camera, sensor, or input/output (I/O) interface. In other embodiments, the components described below may be included in more than one device (e.g., said circuitries may be separately included in more than one device for Cloud-RAN (C-RAN) implementations).

[0073] The application circuitry 802 may include one or more application processors. For example, the application circuitry 802 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors and dedicated processors (e.g., graphics processors, application processors, etc.). The processors may be coupled with or may include memory /storage and may be configured to execute instructions stored in the memory /storage to enable various applications or operating systems to run on the device 800. In some embodiments, processors of application circuitry 802 may process IP data packets received from an EPC.

[0074] The baseband circuitry 804 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The baseband circuitry 804 may include one or more baseband processors or control logic to process baseband signals received from a receive signal path of the RF circuitry 806 and to generate baseband signals for a transmit signal path of the RF circuitry 806. Baseband processing circuity 804 may interface with the application circuitry 802 for generation and processing of the baseband signals and for controlling operations of the RF circuitry 806. For example, in some embodiments, the baseband circuitry 804 may include a third generation (3G) baseband processor 804a, a fourth generation (4G) baseband processor 804b, a fifth generation (5G) baseband processor 804c, or other baseband processor(s) 804d for other existing generations, generations in development or to be developed in the future (e.g., second generation (2G), sixth generation (6G), etc.). The baseband circuitry 804 (e.g., one or more of baseband processors 804a-d) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry 806. In other embodiments, some or all of the functionality of baseband processors 804a-d may be included in modules stored in the memory 804g and executed via a Central Processing Unit (CPU) 804e. The radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some embodiments, modulation/demodulation circuitry of the baseband circuitry 804 may include Fast-Fourier Transform (FFT), precoding, or constellation mapping/demapping functionality. In some embodiments, encoding/decoding circuitry of the baseband circuitry 804 may include convolution, tail-biting convolution, turbo, Viterbi, or Low Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments.

[0075] In some embodiments, the baseband circuitry 804 may include one or more audio digital signal processor(s) (DSP) 804f. The audio DSP(s) 804f may be include elements for compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments. Components of the baseband circuitry may be suitably combined in a single chip, a single chipset, or disposed on a same circuit board in some embodiments. In some embodiments, some or all of the constituent components of the baseband circuitry 804 and the application circuitry 802 may be implemented together such as, for example, on a system on a chip (SOC).

[0076] In some embodiments, the baseband circuitry 804 may provide for

communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry 804 may support communication with an evolved universal terrestrial radio access network (EUTRAN) or other wireless metropolitan area networks (WMAN), a wireless local area network (WLAN), a wireless personal area network (WPAN). Embodiments in which the baseband circuitry 804 is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

[0077] RF circuitry 806 may enable communication with wireless networks

using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry 806 may include switches, filters, amplifiers, etc. to facilitate the communication with the wireless network. RF circuitry 806 may include a receive signal path which may include circuitry to down-convert RF signals received from the FEM circuitry 808 and provide baseband signals to the baseband circuitry 804. RF circuitry 806 may also include a transmit signal path which may include circuitry to up-convert baseband signals provided by the baseband circuitry 804 and provide RF output signals to the FEM circuitry 808 for transmission. [0078] In some embodiments, the receive signal path of the RF circuitry 806 may include mixer circuitry 806a, amplifier circuitry 806b and filter circuitry 806c. In some embodiments, the transmit signal path of the RF circuitry 806 may include filter circuitry 806c and mixer circuitry 806a. RF circuitry 806 may also include synthesizer circuitry 806d for synthesizing a frequency for use by the mixer circuitry 806a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 806a of the receive signal path may be configured to down-convert RF signals received from the FEM circuitry 808 based on the synthesized frequency provided by synthesizer circuitry 806d. The amplifier circuitry 806b may be configured to amplify the down-converted signals and the filter circuitry 806c may be a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry 804 for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although this is not a necessity. In some embodiments, mixer circuitry 806a of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect.

[0079] In some embodiments, the mixer circuitry 806a of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry 806d to generate RF output signals for the FEM circuitry 808. The baseband signals may be provided by the baseband circuitry 804 and may be filtered by filter circuitry 806c.

[0080] In some embodiments, the mixer circuitry 806a of the receive signal path and the mixer circuitry 806a of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and upconversion, respectively. In some embodiments, the mixer circuitry 806a of the receive signal path and the mixer circuitry 806a of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rej ection). In some embodiments, the mixer circuitry 806a of the receive signal path and the mixer circuitry 806a may be arranged for direct downconversion and direct upconversion, respectively. In some embodiments, the mixer circuitry 806a of the receive signal path and the mixer circuitry 806a of the transmit signal path may be configured for super-heterodyne operation. [0081] In some embodiments, the output baseband signals and the input baseband signals may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternate embodiments, the output baseband signals and the input baseband signals may be digital baseband signals. In these alternate embodiments, the RF circuitry 806 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry and the baseband circuitry 804 may include a digital baseband interface to communicate with the RF circuitry 806.

[0082] In some dual-mode embodiments, a separate radio IC circuitry may be provided for processing signals for each spectrum, although the scope of the embodiments is not limited in this respect.

[0083] In some embodiments, the synthesizer circuitry 806d may be a fractional-N synthesizer or a fractional N/N+l synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry 806d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider.

[0084] The synthesizer circuitry 806d may be configured to synthesize an output frequency for use by the mixer circuitry 806a of the RF circuitry 806 based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry 806d may be a fractional N/N+l synthesizer.

[0085] In some embodiments, frequency input may be provided by a voltage controlled oscillator (VCO), although that is not a necessity. Divider control input may be provided by either the baseband circuitry 804 or the applications processor 802 depending on the desired output frequency. In some embodiments, a divider control input (e.g., N) may be determined from a look-up table based on a channel indicated by the applications processor 802.

[0086] Synthesizer circuitry 806d of the RF circuitry 806 may include a divider, a delay- locked loop (DLL), a multiplexer and a phase accumulator. In some embodiments, the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by either N or N+l (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump and a D-type flip-flop. In these embodiments, the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

[0087] In some embodiments, synthesizer circuitry 806d may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a LO frequency (fLO). In some embodiments, the RF circuitry 806 may include an IQ/polar converter.

[0088] FEM circuitry 808 may include a receive signal path which may include circuitry configured to operate on RF signals received from one or more antennas 810, amplify the received signals and provide the amplified versions of the received signals to the RF circuitry 806 for further processing. FEM circuitry 808 may also include a transmit signal path which may include circuitry configured to amplify signals for transmission provided by the RF circuitry 806 for transmission by one or more of the one or more antennas 810. In various embodiments, the amplification through the transmit or receive signal paths may be done solely in the RF circuitry 806, solely in the FEM 808, or in both the RF circuitry 806 and the FEM 808.

[0089] In some embodiments, the FEM circuitry 808 may include a TX/RX switch to switch between transmit mode and receive mode operation. The FEM circuitry may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include an LNA to amplify received RF signals and provide the amplified received RF signals as an output (e.g., to the RF circuitry 806). The transmit signal path of the FEM circuitry 808 may include a power amplifier (PA) to amplify input RF signals (e.g., provided by RF circuitry 806), and one or more filters to generate RF signals for subsequent transmission (e.g., by one or more of the one or more antennas 810). [0090] In some embodiments, the PMC 812 may manage power provided to the baseband circuitry 804. In particular, the PMC 812 may control power-source selection, voltage scaling, battery charging, or DC-to-DC conversion. The PMC 812 may often be included when the device 800 is capable of being powered by a battery, for example, when the device is included in a UE. The PMC 812 may increase the power conversion efficiency while providing desirable implementation size and heat dissipation characteristics.

[0091] While FIG. 8 shows the PMC 812 coupled only with the baseband circuitry 804. However, in other embodiments, the PMC 812 may be additionally or alternatively coupled with, and perform similar power management operations for, other components such as, but not limited to, application circuitry 802, RF circuitry 806, or FEM 808.

[0092] In some embodiments, the PMC 812 may control, or otherwise be part of, various power saving mechanisms of the device 800. For example, if the device 800 is in an RRC_Connected state, where it is still connected to the RAN node as it expects to receive traffic shortly, then it may enter a state known as Discontinuous Reception Mode (DRX) after a period of inactivity. During this state, the device 800 may power down for brief intervals of time and thus save power.

[0093] If there is no data traffic activity for an extended period of time, then the device 800 may transition off to an RRC Idle state, where it disconnects from the network and does not perform operations such as channel quality feedback, handover, etc. The device 800 goes into a very low power state and it performs paging where again it periodically wakes up to listen to the network and then powers down again. The device 800 may not receive data in this state, in order to receive data, it can transition back to

RRC Connected state.

[0094] An additional power saving mode may allow a device to be unavailable to the network for periods longer than a paging interval (ranging from seconds to a few hours). During this time, the device is totally unreachable to the network and may power down completely. Any data sent during this time incurs a large delay and it is assumed the delay is acceptable.

[0095] Processors of the application circuitry 802 and processors of the baseband circuitry 804 may be used to execute elements of one or more instances of a protocol stack. For example, processors of the baseband circuitry 804, alone or in combination, may be used execute Layer 3, Layer 2, or Layer 1 functionality, while processors of the application circuitry 804 may utilize data (e.g., packet data) received from these layers and further execute Layer 4 functionality (e.g., transmission communication protocol (TCP) and user datagram protocol (UDP) layers). As referred to herein, Layer 3 may comprise a radio resource control (RRC) layer, described in further detail below. As referred to herein, Layer 2 may comprise a medium access control (MAC) layer, a radio link control (RLC) layer, and a packet data convergence protocol (PDCP) layer, described in further detail below. As referred to herein, Layer 1 may comprise a physical (PHY) layer of a UE/RAN node, described in further detail below.

[0096] FIG. 9 illustrates example interfaces of baseband circuitry in accordance with some embodiments. As discussed above, the baseband circuitry 804 of FIG. 8 may comprise processors 804a-804e and a memory 804g utilized by said processors. Each of the processors 804a-804e may include a memory interface, 904a-904e, respectively, to send/receive data to/from the memory 804g.

[0097] The baseband circuitry 804 may further include one or more interfaces to communicatively couple to other circuitries/devices, such as a memory interface 912 (e.g., an interface to send/receive data to/from memory external to the baseband circuitry 804), an application circuitry interface 914 (e.g., an interface to send/receive data to/from the application circuitry 802 of FIG. 8), an RF circuitry interface 916 (e.g., an interface to send/receive data to/from RF circuitry 806 of FIG. 8), a wireless hardware connectivity interface 918 (e.g., an interface to send/receive data to/from Near Field Communication (NFC) components, Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi® components, and other communication components), and a power management interface 920 (e.g., an interface to send/receive power or control signals to/from the PMC 812.

[0098] FIG. 10 provides an example illustration of the wireless device, such as a user equipment (UE), a mobile station (MS), a mobile wireless device, a mobile

communication device, a tablet, a handset, or other type of wireless device. The wireless device can include one or more antennas configured to communicate with a node, macro node, low power node (LPN), or, transmission station, such as a base station (BS), an evolved Node B (eNB), a baseband processing unit (BBU), a remote radio head (RRH), a remote radio equipment (RRE), a relay station (RS), a radio equipment (RE), or other type of wireless wide area network (WWAN) access point. The wireless device can be configured to communicate using at least one wireless communication standard such as, but not limited to, 3 GPP LTE, WiMAX, High Speed Packet Access (HSPA), Bluetooth, and WiFi. The wireless device can communicate using separate antennas for each wireless communication standard or shared antennas for multiple wireless communication standards. The wireless device can communicate in a wireless local area network

(WLAN), a wireless personal area network (WPAN), and/or a WWAN. The wireless device can also comprise a wireless modem. The wireless modem can comprise, for example, a wireless radio transceiver and baseband circuitry (e.g., a baseband processor). The wireless modem can, in one example, modulate signals that the wireless device transmits via the one or more antennas and demodulate signals that the wireless device receives via the one or more antennas.

[0099] FIG. 10 also provides an illustration of a microphone and one or more speakers that can be used for audio input and output from the wireless device. The display screen can be a liquid crystal display (LCD) screen, or other type of display screen such as an organic light emitting diode (OLED) display. The display screen can be configured as a touch screen. The touch screen can use capacitive, resistive, or another type of touch screen technology. An application processor and a graphics processor can be coupled to internal memory to provide processing and display capabilities. A non-volatile memory port can also be used to provide data input/output options to a user. The non-volatile memory port can also be used to expand the memory capabilities of the wireless device. A keyboard can be integrated with the wireless device or wirelessly connected to the wireless device to provide additional user input. A virtual keyboard can also be provided using the touch screen.

Examples

[00100] The following examples pertain to specific technology embodiments and point out specific features, elements, or actions that can be used or otherwise combined in achieving such embodiments.

[00101] Example 1 includes an apparatus of a first next generation node B (gNB) operable to measure crosslink signal-to-interference ratio (SINR) in a dynamic time division duplex (TDD) new radio (NR) system relative to a second gNB, the apparatus comprising: one or more processors configured to: encode, at the first gNB, a downlink interference measurement reference signal (IM-RS), for transmission to a first user equipment (UE), in a selected comb of an IFDMA comb structure having n combs, wherein n is a positive integer; decode, at the first gNB, an uplink IM-RS from a second UE received in one of the n combs in the IFDMA comb structure, wherein the uplink IM- RS is time aligned with the downlink IM-RS; and determine, at the first gNB, the crosslink interference in the IFDMA comb structure, caused by one or more of the second gNB and the second UE, based on the downlink IM-RS and the uplink IM-RS; and a memory interface configured to receive, from a memory, data associated with the downlink IM-RS.

[00102] Example 2 includes the apparatus of Example 1, wherein the one or more processors are further configured to: encode the downlink IM-RS as a non-zero power reference signal; or decode the uplink IM-RS as a non-zero power reference signal.

[00103] Example 3 includes the apparatus of Example 1, wherein the one or more processors are further configured to: encode the downlink IM-RS and decode the uplink IM-RS as a same sequence type or a different sequence type, wherein the sequence type includes one of: a pseudo-random noise (PN) sequence, a Zadoff Chu (ZC) sequence, or a Golay sequence.

[00104] Example 4 includes the apparatus of any of Examples 1 to 3, wherein the one or more processors are further configured to: encode the downlink IM-RS as non- precoded or precoded; or decode the uplink IM-RS as non-precoded or precoded.

[00105] Example 5 includes the apparatus of any of Examples 1 to 3, wherein the one or more processors are further configured to: encode the downlink IM-RS via physical layer signaling or higher layer signaling; or decode the uplink IM-RS via physical layer signaling or higher layer signaling.

[00106] Example 6 includes the apparatus of any of Examples 1 to 3, wherein the one or more processors are further configured to measure a crosslink interference from a plurality of uplink IM-RSs using one or more of: frequency division multiplexing (FDM) or cyclic time-domain shifts.

[00107] Example 7 includes the apparatus of Example 1, wherein each comb comprises a plurality of subcarriers that are interleaved with subcarriers of other combs in the n combs.

[00108] Example 8 includes the apparatus of any of Examples 1 to 3, wherein one or more interference measurement resource (IMR) parameters are configured including: IMR comb frequency offset; physical resource block (PRB) indices; or subframe indices.

[00109] Example 9 includes an apparatus of a first user equipment (UE) operable to measure crosslink signal-to-interference ratio (SINR) in a dynamic time division duplex (TDD) new radio (NR) system relative to a second UE, the apparatus comprising: one or more processors configured to: encode, at the first UE, an uplink interference measurement reference signal (IM-RS), for transmission to a first next generation node B (gNB), in a selected comb of an IFDMA comb structure having n combs, wherein n is a positive integer; decode, at the first UE, a downlink IM-RS from a second gNB received in one of the n combs in the IFDMA comb structure, wherein the downlink IM-RS is time aligned with the uplink IM-RS; and determine, at the first UE, the crosslink interference in the IFDMA comb structure, caused by one or more of the second UE and the second gNB, based on the downlink IM-RS and the uplink IM-RS; and a memory interface configured to receive, from a memory, data associated with the uplink IM-RS.

[00110] Example 10 includes the apparatus of Example 9, wherein the one or more processors are further configured to: encode the uplink IM-RS as a non-zero power reference signal; or decode the downlink IM-RS as a non-zero power reference signal.

[00111] Example 11 includes the apparatus of Example 9, wherein the one or more processors are further configured to encode the uplink IM-RS and decode the downlink IM-RS as a same sequence type or a different sequence type, wherein the sequence type includes one of: a pseudo-random noise (PN) sequence, a Zadoff Chu (ZC) sequence, or a Golay sequence.

[00112] Example 12 includes the apparatus of any of Examples 9 to 11, wherein the one or more processors are further configured to: encode the uplink IM-RS as non- precoded or precoded; or decode the downlink IM-RS as non-precoded or precoded.

[00113] Example 13 includes the apparatus of any of Examples 9 to 11, wherein the one or more processors are further configured to: encode the uplink IM-RS via physical layer signaling or higher layer signaling; or decode the downlink IM-RS via physical layer signaling or higher layer signaling.

[00114] Example 14 includes the apparatus of example 9, wherein each comb comprises a plurality of subcarriers that are interleaved with subcarriers of other combs in the n combs.

[00115] Example 15 includes the apparatus of any of Examples 9 to 11, wherein one or more interference measurement resource (IMR) parameters are configured including: IMR comb frequency offset; physical resource block (PRB) indices; or subframe indices.

[00116] Example 16 includes at least one machine readable storage medium having instructions embodied thereon for measuring crosslink signal-to-interference ratio (SINR) in a dynamic time division duplex (TDD) new radio (NR) system, the instructions when executed by one or more processors at a first next generation node B (gNB) perform the following: encoding, at the first gNB, a downlink interference measurement reference signal (IM-RS), for transmission to a first user equipment (UE), in a selected comb of an IFDMA comb structure having n combs, wherein n is a positive integer; decoding, at the first gNB, an uplink IM-RS from a second UE received in one of the n combs in the IFDMA comb structure, wherein the uplink IM-RS is time aligned with the downlink IM- RS; and determining, at the first gNB, the crosslink interference in the IFDMA comb structure, caused by one or more of the second gNB and the second UE, based on the downlink IM-RS and the uplink IM-RS.

[00117] Example 17 includes the at least one machine readable storage medium of Example 16, further comprising instructions, when executed, perform: encoding the downlink IM-RS as a non-zero power reference signal; or decoding the uplink IM-RS as a non-zero power reference signal.

[00118] Example 18 includes the at least one machine readable storage medium of Example 16, further comprising instructions, when executed, perform: encoding the downlink IM-RS and decode the uplink IM-RS as a same sequence type or a different sequence type, wherein the sequence type includes one of: a pseudo-random noise (PN) sequence, a Zadoff Chu (ZC) sequence, or a Golay sequence.

[00119] Example 19 includes The at least one machine readable storage medium of any of Examples 16 to 18, further comprising instructions, when executed, perform: encoding the downlink IM-RS as non-precoded or precoded; or decoding the uplink IM- RS as non-precoded or precoded.

[00120] Example 20 includes the at least one machine readable storage medium of any of Examples 16 to 18, further comprising instructions, when executed, perform: encoding the downlink IM-RS via physical layer signaling or higher layer signaling; or decoding the uplink IM-RS via physical layer signaling or higher layer signaling.

[00121] Example 21 includes the at least one machine readable storage medium of any of Examples 16 to 18, further comprising instructions, when executed, perform:

measuring a crosslink interference from a plurality of uplink IM-RSs using one or more of: frequency division multiplexing (FDM) or cyclic time-domain shifts.

[00122] Example 22 includes the at least one machine readable storage medium of Example 16, wherein each comb comprises a plurality of subcarriers that are interleaved with subcarriers of other combs in the n combs.

[00123] Example 23 includes the at least one machine readable storage medium of any of Examples 16 to 18, wherein one or more interference measurement resource (IMR) parameters are configured including: IMR comb frequency offset; physical resource block (PRB) indices; or subframe indices.

[00124] Example 24 includes a user equipment (UE) operable for measuring crosslink signal-to-interference ratio (SINR) in a dynamic time division duplex (TDD) new radio (NR) system, the UE comprising: means for encoding, at the first gNB, a downlink interference measurement reference signal (IM-RS), for transmission to a first user equipment (UE), in a selected comb of an IFDMA comb structure having n combs, wherein n is a positive integer; means for decoding, at the first gNB, an uplink IM-RS from a second UE received in one of the n combs in the IFDMA comb structure, wherein the uplink IM-RS is time aligned with the downlink IM-RS; and means for determining, at the first gNB, the crosslink interference in the IFDMA comb structure, caused by one or more of the second gNB and the second UE, based on the downlink IM-RS and the uplink IM-RS.

[00125] Example 25 includes the UE of Example 24, the UE further comprising: means for encoding the downlink IM-RS as a non-zero power reference signal; or means for decoding the uplink IM-RS as a non-zero power reference signal.

[00126] Example 26 includes the UE of Example 24, the UE further comprising: means for encoding the downlink IM-RS and decode the uplink IM-RS as a same sequence type or a different sequence type, wherein the sequence type includes one of: a pseudo-random noise (PN) sequence, a Zadoff Chu (ZC) sequence, or a Golay sequence.

[00127] Example 27 includes the UE of any of Examples 24 to 26, the UE further comprising: means for encoding the downlink IM-RS as non-precoded or precoded; or means for decoding the uplink IM-RS as non-precoded or precoded.

[00128] Example 28 includes the UE of any of Examples 24 to 26, the UE further comprising: means for encoding the downlink IM-RS via physical layer signaling or higher layer signaling; or means for decoding the uplink IM-RS via physical layer signaling or higher layer signaling.

[00129] Example 29 includes the UE of any of Examples 24 to 26, the UE further comprising: means for measuring a crosslink interference from a plurality of uplink IM- RSs using one or more of: frequency division multiplexing (FDM) or cyclic time-domain shifts.

[00130] Example 30 includes the UE of Example 24, wherein each comb comprises a plurality of subcarriers that are interleaved with subcarriers of other combs in the n combs.

[00131] Example 31 includes the UE of any of Examples 24 to 26, wherein one or more interference measurement resource (IMR) parameters are configured including: IMR comb frequency offset; physical resource block (PRB) indices; or subframe indices.

[00132] Example 32 includes an apparatus of a first next generation node B (gNB) operable to measure crosslink signal-to-interference ratio (SINR) in a dynamic time division duplex (TDD) new radio (NR) system relative to a second gNB, the apparatus comprising: one or more processors configured to: encode, at the first gNB, a downlink interference measurement reference signal (IM-RS), for transmission to a first user equipment (UE), in a selected comb of an IFDMA comb structure having n combs, wherein n is a positive integer; decode, at the first gNB, an uplink IM-RS from a second UE received in one of the n combs in the IFDMA comb structure, wherein the uplink IM- RS is time aligned with the downlink IM-RS; and determine, at the first gNB, the crosslink interference in the IFDMA comb structure, caused by one or more of the second gNB and the second UE, based on the downlink IM-RS and the uplink IM-RS; and a memory interface configured to receive, from a memory, data associated with the downlink IM-RS.

[00133] Example 33 includes the apparatus of Example 32, wherein the one or more processors are further configured to: encode the downlink IM-RS as a non-zero power reference signal; decode the uplink IM-RS as a non-zero power reference signal; encode the downlink IM-RS and decode the uplink IM-RS as a same sequence type or a different sequence type, wherein the sequence type includes one of: a pseudo-random noise (PN) sequence, a Zadoff Chu (ZC) sequence, or a Golay sequence; encode the downlink IM-RS as non-precoded or precoded; decode the uplink IM-RS as non-precoded or precoded; encode the downlink IM-RS via physical layer signaling or higher layer signaling; or decode the uplink IM-RS via physical layer signaling or higher layer signaling.

[00134] Example 34 includes the apparatus of any of Examples 32 to 33, wherein the one or more processors are further configured to measure a crosslink interference from a plurality of uplink IM-RSs using one or more of: frequency division multiplexing (FDM) or cyclic time-domain shifts.

[00135] Example 35 includes the apparatus of any of Examples 32 to 33, wherein each comb comprises a plurality of subcarriers that are interleaved with subcarriers of other combs in the n combs.

[00136] Example 36 includes the apparatus of any of Examples 32 to 33, wherein one or more interference measurement resource (IMR) parameters are configured including: IMR comb frequency offset; physical resource block (PRB) indices; or subframe indices.

[00137] Example 37 includes an apparatus of a first user equipment (UE) operable to measure crosslink signal-to-interference ratio (SINR) in a dynamic time division duplex (TDD) new radio (NR) system relative to a second UE, the apparatus comprising: one or more processors configured to: encode, at the first UE, an uplink interference

measurement reference signal (IM-RS), for transmission to a first next generation node B (gNB), in a selected comb of an IFDMA comb structure having n combs, wherein n is a positive integer; decode, at the first UE, a downlink IM-RS from a second gNB received in one of the n combs in the IFDMA comb structure, wherein the downlink IM-RS is time aligned with the uplink IM-RS; and determine, at the first UE, the crosslink interference in the IFDMA comb structure, caused by one or more of the second UE and the second gNB, based on the downlink IM-RS and the uplink IM-RS; and a memory interface configured to receive, from a memory, data associated with the uplink IM-RS.

[00138] Example 38 includes the apparatus of Example 37, wherein the one or more processors are further configured to: encode the uplink IM-RS as a non-zero power reference signal; decode the downlink IM-RS as a non-zero power reference signal; encode the uplink IM-RS and decode the downlink IM-RS as a same sequence type or a different sequence type, wherein the sequence type includes one of: a pseudo-random noise (PN) sequence, a Zadoff Chu (ZC) sequence, or a Golay sequence; encode the uplink IM-RS as non-precoded or precoded; decode the downlink IM-RS as non- precoded or precoded encode the uplink IM-RS via physical layer signaling or higher layer signaling; or decode the downlink IM-RS via physical layer signaling or higher layer signaling.

[00139] Example 39 includes the apparatus of any of Examples 37 to 38, wherein each comb comprises a plurality of subcarriers that are interleaved with subcarriers of other combs in the n combs.

[00140] Example 40 includes the apparatus of any of Examples 37 to 38, wherein one or more interference measurement resource (IMR) parameters are configured including: IMR comb frequency offset; physical resource block (PRB) indices; or subframe indices.

[00141] Example 41 includes at least one machine readable storage medium having instructions embodied thereon for measuring crosslink signal-to-interference ratio (SINR) in a dynamic time division duplex (TDD) new radio (NR) system, the instructions when executed by one or more processors at a first next generation node B (gNB) perform the following: encoding, at the first gNB, a downlink interference measurement reference signal (IM-RS), for transmission to a first user equipment (UE), in a selected comb of an IFDMA comb structure having n combs, wherein n is a positive integer; decoding, at the first gNB, an uplink IM-RS from a second UE received in one of the n combs in the

IFDMA comb structure, wherein the uplink IM-RS is time aligned with the downlink IM- RS; and determining, at the first gNB, the crosslink interference in the IFDMA comb structure, caused by one or more of the second gNB and the second UE, based on the downlink IM-RS and the uplink IM-RS.

[00142] Example 42 includes the at least one machine readable storage medium of Example 41, further comprising instructions, when executed, perform: encoding the downlink IM-RS as a non-zero power reference signal; decoding the uplink IM-RS as a non-zero power reference signal; encoding the downlink IM-RS and decode the uplink IM-RS as a same sequence type or a different sequence type, wherein the sequence type includes one of: a pseudo-random noise (PN) sequence, a Zadoff Chu (ZC) sequence, or a Golay sequence; encoding the downlink IM-RS as non-precoded or precoded; or decoding the uplink IM-RS as non-precoded or precoded.

[00143] Example 43 includes the at least one machine readable storage medium of any of Examples 41 to 42, further comprising instructions, when executed, perform: encoding the downlink IM-RS via physical layer signaling or higher layer signaling; or decoding the uplink IM-RS via physical layer signaling or higher layer signaling.

[00144] Example 44 includes the at least one machine readable storage medium of any of Examples 41 to 42, further comprising instructions, when executed, perform:

measuring a crosslink interference from a plurality of uplink IM-RSs using one or more of: frequency division multiplexing (FDM) or cyclic time-domain shifts.

[00145] Example 45 includes the at least one machine readable storage medium of any of Examples 41 to 42, wherein each comb comprises a plurality of subcarriers that are interleaved with subcarriers of other combs in the n combs.

[00146] Example 46 includes the at least one machine readable storage medium of any of Examples 41 to 42, wherein one or more interference measurement resource (IMR) parameters are configured including: IMR comb frequency offset; physical resource block (PRB) indices; or subframe indices.

[00147] Various techniques, or certain aspects or portions thereof, may take the form of program code (i.e., instructions) embodied in tangible media, such as floppy diskettes, compact disc-read-only memory (CD-ROMs), hard drives, non-transitory computer readable storage medium, or any other machine-readable storage medium wherein, when the program code is loaded into and executed by a machine, such as a computer, the machine becomes an apparatus for practicing the various techniques. In the case of program code execution on programmable computers, the computing device may include a processor, a storage medium readable by the processor (including volatile and non- volatile memory and/or storage elements), at least one input device, and at least one output device. The volatile and non-volatile memory and/or storage elements may be a random-access memory (RAM), erasable programmable read only memory (EPROM), flash drive, optical drive, magnetic hard drive, solid state drive, or other medium for storing electronic data. The node and wireless device may also include a transceiver module (i.e., transceiver), a counter module (i.e., counter), a processing module (i.e., processor), and/or a clock module (i.e., clock) or timer module (i.e., timer). In one example, selected components of the transceiver module can be located in a cloud radio access network (C-RAN). One or more programs that may implement or utilize the various techniques described herein may use an application programming interface (API), reusable controls, and the like. Such programs may be implemented in a high level procedural or object oriented programming language to communicate with a computer system. However, the program(s) may be implemented in assembly or machine language, if desired. In any case, the language may be a compiled or interpreted language, and combined with hardware implementations.

[00148] As used herein, the term "circuitry" may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group), and/or memory (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality. In some embodiments, the circuitry may be implemented in, or functions associated with the circuitry may be implemented by, one or more software or firmware modules. In some embodiments, circuitry may include logic, at least partially operable in hardware.

[00149] It should be understood that many of the functional units described in this specification have been labeled as modules, in order to more particularly emphasize their implementation independence. For example, a module may be implemented as a hardware circuit comprising custom very-large-scale integration (VLSI) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices or the like.

[00150] Modules may also be implemented in software for execution by various types of processors. An identified module of executable code may, for instance, comprise one or more physical or logical blocks of computer instructions, which may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module may not be physically located together, but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the module and achieve the stated purpose for the module.

[00151] Indeed, a module of executable code may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different storage devices, and may exist, at least partially, merely as electronic signals on a system or network. The modules may be passive or active, including agents operable to perform desired functions.

[00152] Reference throughout this specification to "an example" or "exemplary" means that a particular feature, structure, or characteristic described in connection with the example is included in at least one embodiment of the present technology. Thus, appearances of the phrases "in an example" or the word "exemplary" in various places throughout this specification are not necessarily all referring to the same embodiment.

[00153] As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary. In addition, various embodiments and example of the present technology may be referred to herein along with alternatives for the various components thereof. It is understood that such embodiments, examples, and alternatives are not to be construed as defacto equivalents of one another, but are to be considered as separate and autonomous representations of the present technology.

[00154] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of layouts, distances, network examples, etc., to provide a thorough understanding of embodiments of the technology. One skilled in the relevant art will recognize, however, that the technology can be practiced without one or more of the specific details, or with other methods, components, layouts, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the technology.

[00155] While the forgoing examples are illustrative of the principles of the present technology in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the technology. Accordingly, it is not intended that the technology be limited, except as by the claims set forth below.