CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to United States Provisional Patent Application Number 63/105,092 entitled “SL CSI ENHANCEMENTS” and fried on October 22, 2020 for Karthikeyan Ganesan, Joachim Loehr, Prateek Basu Mallick, and Ankit Bhamri, which application is incorporated herein by reference.

FIELD

[0002] The subject matter disclosed herein relates generally to wireless communications and more particularly relates to sidelink channel state information (“CSI”) enhancements.

BACKGROUND

[0003] In sidelink communication, a User Equipment (“UE”) is able to communicate directly with another UE and without relaying its messages via a wireless network.

BRIEF SUMMARY

[0004] Disclosed are procedures for sidelink CSI. Said procedures may be implemented by apparatus, systems, methods, or computer program products.

[0005] One method of a Transmitter User Equipment (“Tx UE”) for resource-specific CSI reporting includes transmitting a Channel State Information Reference Signal (“CSI-RS”) within a sidelink data region and transmitting a Channel State Information (“CSI”) request indicator in Sidelink Control Information (“SCI”), the CSI request associated with a first resource pool. The method includes transmitting an aperiodic CSI trigger corresponding to a second resource pool separate from the first resource pool and receiving a first CSI report in response to the CSI request, where the aperiodic CSI trigger corresponding to the second resource pool is sent prior to receipt of the first CSI report. The method includes receiving an aperiodic CSI report in response to the aperiodic CSI trigger.

[0006] One method of a Receiver User Equipment (“Rx UE”) for resource-specific CSI reporting includes receiving a CSI-RS within a sidelink data region and receiving a CSI request indicator in SCI, the CSI request associated with a first resource pool. The method includes receiving an aperiodic CSI trigger corresponding to a second resource pool and transmitting a first CSI report in response to the CSI request, where the aperiodic CSI trigger corresponding to the second resource pool is sent prior to receipt of the first CSI report. The method includes transmitting an aperiodic CSI report in response to the aperiodic CSI trigger, where a CSI report window of the first CSI report overlaps with a CSI report window of the aperiodic CSI report.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] A more particular description of the embodiments briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only some embodiments and are not therefore to be considered to be limiting of scope, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:

[0008] Figure 1 is a block diagram illustrating one embodiment of a wireless communication system for resource-specific CSI reporting;

[0009] Figure 2A is a diagram illustrating one association between CSI trigger and CSI report reception;

[0010] Figure 2B is a diagram illustrating one embodiment of a Sidelink CSI Reporting Medium Access Control (“MAC”) Control Element (“CE”);

[0011] Figure 3 is a diagram illustrating one embodiment of multiple CSI trigger and report considering resource pool;

[0012] Figure 4A is a diagram illustrating one embodiment of periodic CSI Reference Signal (“CSI-RS”) and aperiodic CSI trigger;

[0013] Figure 4B is a diagram illustrating another embodiment of periodic CSI-RS and aperiodic CSI trigger;

[0014] Figure 5 is a diagram illustrating one embodiment of Sidelink (“SL”) configured grant;

[0015] Figure 6 is a diagram illustrating one embodiment of periodic configuration of report;

[0016] Figure 7A is a diagram illustrating one embodiment of inter-UE coordination communication;

[0017] Figure 7B is a block diagram illustrating one embodiment of a PC5 protocol stack for a sidelink interface;

[0018] Figure 8 is a block diagram illustrating one embodiment of a user equipment apparatus that may be used for resource-specific CSI reporting;

[0019] Figure 9 is a block diagram illustrating one embodiment of a network apparatus that may be used for resource-specific CSI reporting; [0020] Figure 10 is a flowchart diagram illustrating one embodiment of a first method for resource-specific CSI reporting; and

[0021] Figure 11 is a flowchart diagram illustrating one embodiment of a second method for resource-specific CSI reporting.

DETAILED DESCRIPTION

[0022] As will be appreciated by one skilled in the art, aspects of the embodiments may be embodied as a system, apparatus, method, or program product. Accordingly, embodiments may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects.

[0023] For example, the disclosed embodiments 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. The disclosed embodiments may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices, or the like. As another example, the disclosed embodiments may include one or more physical or logical blocks of executable code which may, for instance, be organized as an object, procedure, or function.

[0024] Furthermore, embodiments may take the form of a program product embodied in one or more computer readable storage devices storing machine readable code, computer readable code, and/or program code, referred hereafter as code. The storage devices may be tangible, non- transitory, and/or non-transmission. The storage devices may not embody signals. In a certain embodiment, the storage devices only employ signals for accessing code.

[0025] Any combination of one or more computer readable medium may be utilized. The computer readable medium may be a computer readable storage medium. The computer readable storage medium may be a storage device storing the code. The storage device may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

[0026] More specific examples (a non-exhaustive list) of the storage device would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random-access memory (“RAM”), a read-only memory (“ROM”), an erasable programmable read-only memory (“EPROM” or Flash memory), a portable compact disc readonly memory (“CD-ROM”), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device.

[0027] Code for carrying out operations for embodiments may be any number of lines and may be written in any combination of one or more programming languages including an object- oriented programming language such as Python, Ruby, Java, Smalltalk, C++, or the like, and conventional procedural programming languages, such as the "C" programming language, or the like, and/or machine languages such as assembly languages. The code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (“LAN”), wireless LAN (“WLAN”), or a wide area network (“WAN”), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider (“ISP”)).

[0028] Furthermore, the described features, structures, or characteristics of the embodiments may be combined in any suitable manner. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that embodiments may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of an embodiment.

[0029] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to,” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise. [0030] As used herein, a list with a conjunction of “and/or” includes any single item in the list or a combination of items in the list. For example, a list of A, B and/or C includes only A, only B, only C, a combination of A and B, a combination of B and C, a combination of A and C or a combination of A, B and C. As used herein, a list using the terminology “one or more of’ includes any single item in the list or a combination of items in the list. For example, one or more of A, B and C includes only A, only B, only C, a combination of A and B, a combination of B and C, a combination of A and C or a combination of A, B and C. As used herein, a list using the terminology “one of’ includes one and only one of any single item in the list. For example, “one of A, B and C” includes only A, only B or only C and excludes combinations of A, B and C. As used herein, “a member selected from the group consisting of A, B, and C,” includes one and only one of A, B, or C, and excludes combinations of A, B, and C.” As used herein, “a member selected from the group consisting of A, B, and C and combinations thereof’ includes only A, only B, only C, a combination of A and B, a combination of B and C, a combination of A and C or a combination of A, B and C.

[0031] Aspects of the embodiments are described below with reference to schematic flowchart diagrams and/or schematic block diagrams of methods, apparatuses, systems, and program products according to embodiments. It will be understood that each block of the schematic flowchart diagrams and/or schematic block diagrams, and combinations of blocks in the schematic flowchart diagrams and/or schematic block diagrams, can be implemented by code. This code may be provided to a processor of a general-purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart diagrams and/or block diagrams.

[0032] The code may also be stored in a storage device that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the storage device produce an article of manufacture including instructions which implement the function/act specified in the flowchart diagrams and/or block diagrams.

[0033] The code may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the code which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart diagrams and/or block diagrams. [0034] The call-flow diagrams, flowchart diagrams and/or block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of apparatuses, systems, methods, and program products according to various embodiments. In this regard, each block in the flowchart diagrams and/or block diagrams may represent a module, segment, or portion of code, which includes one or more executable instructions of the code for implementing the specified logical function(s).

[0035] It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more blocks, or portions thereof, of the illustrated Figures.

[0036] Although various arrow types and line types may be employed in the call -flow, flowchart and/or block diagrams, they are understood not to limit the scope of the corresponding embodiments. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the depicted embodiment. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted embodiment. It will also be noted that each block of the block diagrams and/or flowchart diagrams, and combinations of blocks in the block diagrams and/or flowchart diagrams, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and code.

[0037] The description of elements in each figure may refer to elements of proceeding figures. Like numbers refer to like elements in all figures, including alternate embodiments of like elements.

[0038] Generally, the present disclosure describes systems, methods, and apparatus for resource-specific CSI reporting. In certain embodiments, the methods may be performed using computer code embedded on a computer-readable medium. In certain embodiments, an apparatus or system may include a computer-readable medium containing computer-readable code which, when executed by a processor, causes the apparatus or system to perform at least a portion of the below described solutions.

[0039] Sidelink CSI feature of transmitting the SL CSI-RS and aperiodic CSI report request trigger was introduced in New Radio (“NR”) Sidelink Release 16 (“Rel-16”). However, 3GPP Rel-16 specifications do not support multiple concurrent CSI reporting trigger by a UE, e.g., to keep the minimal specification impact, and hence a legacy UE is not allowed to trigger another aperiodic CSI report for the same UE before the last slot of the expected reception or completion of the ongoing aperiodic CSI report.

[0040] This restriction imposes problem for the Tx UE because only the instantaneous variation of the Signal-to-Interference-Plus-Noise Ratio (“SINR”) for the slot where the CSI-RS is transmitted is reported back in the CSI report within the configured latency bound but the SINR can be varying slot by slot basis and hence the instantaneous reporting of SL CSI report cannot map the accurate channel variation. Additionally, a Peer UE with established unicast session could transmit and receive in multiple resource pool and there is no linkage between unicast session and the resource pool in the current specification. Hence, the Tx UE may choose to transmit in multiple resource pool to Rx UE based on the CBR/CR (channel busy ratio/channel occupancy ratio) measurement report and priority of the data (currently the resource pool selection is based on the priority of the data).

[0041] To improve scheduling flexibility, the below solutions describe mechanisms to transmit multiple aperiodic CSI report triggering in parallel, e.g., with respect to different resource pools, different beam/panel/spatial-filter, etc.

[0042] In some embodiments, a transmitter UE (“Tx UE”) associates the CSI trigger and CSI report per Resource pool and Tx UE may transmit a trigger for aperiodic CSI reporting request and receive corresponding CSI report for each of the resource pool separately, unless an ongoing CSI report reception corresponding to that resource pool is already pending. In certain embodiments, there is configuration of multiple CSI report latency in PC5 Radio Resource Control (“RRC”), each configuration of latency bound is associated per resource pool or a priority value in SCI. Note that SCI may include 3 bits to indicate the priority (e.g., see SCI format 0-1). Note that PC5 is the name of the 3GPP reference point where one UE directly communicates with another UE and therefore refers to the D2D sidelink interface in 3GPP.

[0043] In certain embodiments, the maintenance of sl-CSI-ReportTimer and SL CSI event may be per CSI trigger per resource pool. The Logical Channel Prioritization (“LCP”) procedure at the Rx UE may consider prioritization rule for the transmission of plurality of CSI report.

[0044] In some embodiments, the association between aperiodic CSI trigger and CSI reporting may be based on one or more or a combination of the following: A) MAC CE may additionally report Resource Pool ID for which the measurement was performed; B) SCI indicates the Resource Pool ID to be used for the transmission of CSI report; C) SCI and MAC CE indicates the trigger index or sequence number; D) MAC CE includes the slot index of the received trigger.

[0045] In various embodiments, there is periodic CSI-RS transmission within Physical Sidelink Shared Channel (“PSSCH”) resource and the activation/deactivation periodic CSI-RS to the Rx UE/destination ID. In certain embodiments, the transmission of aperiodic CSI trigger occurs separately after the last CSI-RS occasion enabling the Rx UE to transmit a CSI report considering plurality of CSI-RS occasion. Alternatively, the transmission of aperiodic CSI trigger occurs together with the last CSI-RS occasion enabling the Rx UE to transmit a CSI report considering plurality of CSI-RS occasions.

[0046] In various embodiments, there is configuration and activation/deactivation of the periodic CSI-RS transmission within the configured grant (“CG”) resource period, CSI-RS can be configured to be transmitted in each of the CG resource or in one of the CG resources in a period. In certain embodiments, configuration, and activation/deactivation of the periodic CSI reporting at the end of each period or every second periods.

[0047] In various embodiments, association of the CSI trigger and CSI report per beam/ panel/spatial-filter and then the Tx UE may transmit a trigger for aperiodic CSI reporting request and receive corresponding CSI report for each of the beam/panel/spatial-filter separately unless an ongoing CSI report reception corresponding to that beam/panel/spatial-filter is already pending.

[0048] Figure 1 depicts a wireless communication system 100 for SL CSI for wireless devices communicating via Sidelink (“SL”) signaling 115, according to embodiments of the disclosure. In one embodiment, the wireless communication system 100 includes at least one remote unit 105, a radio access network (“RAN”) 120, and a mobile core network 140. The RAN 120 and the mobile core network 140 form a mobile communication network. The RAN 120 may be composed of a base unit 121 with which the remote unit 105 communicates using wireless communication links 123. Even though a specific number of remote units 105, base units 121, wireless communication links 123, RANs 120, and mobile core networks 140 are depicted in Figure 1, one of skill in the art will recognize that any number of remote units 105, base units 121, wireless communication links 123, RANs 120, and mobile core networks 140 may be included in the wireless communication system 100.

[0049] In one implementation, the RAN 120 is compliant with the Fifth Generation (“5G”) system specified in the Third Generation Partnership Project (“3GPP”) specifications. For example, the RAN 120 may be a Next Generation Radio Access Network (“NG-RAN”), implementing New Radio (“NR”) Radio Access Technology (“RAT”) and/or Long-Term Evolution (“LTE”) RAT. In another example, the RAN 120 may include non-3GPP RAT (e.g., Wi-Fi® or Institute of Electrical and Electronics Engineers (“IEEE”) 802.11-family compliant WLAN). In another implementation, the RAN 120 is compliant with the LTE system specified in the 3GPP specifications. More generally, however, the wireless communication system 100 may implement some other open or proprietary communication network, for example Worldwide Interoperability for Microwave Access (“WiMAX”) or IEEE 802.16-family standards, among other networks. The present disclosure is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol.

[0050] In one embodiment, the remote units 105 may include computing devices, such as desktop computers, laptop computers, personal digital assistants (“PDAs”), tablet computers, smart phones, smart televisions (e.g., televisions connected to the Internet), smart appliances (e.g., appliances connected to the Internet), set-top boxes, game consoles, security systems (including security cameras), vehicle on-board computers, network devices (e.g., routers, switches, modems), or the like. In some embodiments, the remote units 105 include wearable devices, such as smart watches, fitness bands, optical head-mounted displays, or the like. Moreover, the remote units 105 may be referred to as the UEs, subscriber units, mobiles, mobile stations, users, terminals, mobile terminals, fixed terminals, subscriber stations, user terminals, wireless transmit/receive unit (”WTRU”), a device, or by other terminology used in the art. In various embodiments, the remote unit 105 includes a subscriber identity and/or identification module (“SIM”) and the mobile equipment (“ME”) providing mobile termination functions (e.g., radio transmission, handover, speech encoding and decoding, error detection and correction, signaling and access to the SIM). In certain embodiments, the remote unit 105 may include a terminal equipment (“TE”) and/or be embedded in an appliance or device (e.g., a computing device, as described above).

[0051] The remote units 105 may communicate directly with one or more of the base units 121 in the RAN 120 via uplink (“UL”) and downlink (“DL”) communication signals. Furthermore, the UL and DL communication signals may be carried over the wireless communication links 123. Here, the RAN 120 is an intermediate network that provides the remote units 105 with access to the mobile core network 140.

[0052] In some embodiments, the remote units 105 communicate with an application server 151 via a network connection with the mobile core network 140. For example, an application 107 (e.g., web browser, media client, telephone and/or Voice-over-Intemet-Protocol (“VoIP”) application) in a remote unit 105 may trigger the remote unit 105 to establish a protocol data unit (“PDU”) session (or other data connection) with the mobile core network 140 via the RAN 120. The mobile core network 140 then relays traffic between the remote unit 105 and the application server 151 in the packet data network 150 using the PDU session. The PDU session represents a logical connection between the remote unit 105 and the User Plane Function (“UPF”) 141.

[0053] In order to establish the PDU session (or Packet Data Network (“PDN”) connection), the remote unit 105 must be registered with the mobile core network 140 (also referred to as “attached to the mobile core network” in the context of a Fourth Generation (“4G”) system). Note that the remote unit 105 may establish one or more PDU sessions (or other data connections) with the mobile core network 140. As such, the remote unit 105 may concurrently have at least one PDU session for communicating with the packet data network 150. The remote unit 105 may establish additional PDU sessions for communicating with other data networks and/or other communication peers.

[0054] In the context of a 5G system (“5GS”), the term “PDU Session” refers to a data connection that provides end-to-end (“E2E”) user plane (“UP”) connectivity between the remote unit 105 and a specific Data Network (“DN”) through the UPF 141. A PDU Session supports one or more Quality of Service (“QoS”) Flows. In certain embodiments, there may be a one-to-one mapping between a QoS Flow and a QoS profile, such that all packets belonging to a specific QoS Flow have the same 5G QoS Identifier (“5QI”).

[0055] In the context of a 4G/UTE system, such as the Evolved Packet System (“EPS”), a PDN connection (also referred to as EPS session) provides E2E UP connectivity between the remote unit and a PDN. The PDN connectivity procedure establishes an EPS Bearer, i.e., a tunnel between the remote unit 105 and a Packet Gateway (“PGW”, not shown) in the mobile core network 140. In certain embodiments, there is a one-to-one mapping between an EPS Bearer and a QoS profile, such that all packets belonging to a specific EPS Bearer have the same QoS Class Identifier (“QCI”).

[0056] The base units 121 may be distributed over a geographic region. In certain embodiments, a base unit 121 may also be referred to as an access terminal, an access point, a base, a base station, aNode-B (“NB”), an Evolved Node B (abbreviated as eNodeB or “eNB,” also known as Evolved Universal Terrestrial Radio Access Network (“E-UTRAN”) Node B), a 5G/NR Node B (“gNB”), a Home Node-B, a relay node, a RAN node, or by any other terminology used in the art. The base units 121 are generally part of a RAN, such as the RAN 120, that may include one or more controllers communicably coupled to one or more corresponding base units 121. These and other elements of radio access network are not illustrated but are well known generally by those having ordinary skill in the art. The base units 121 connect to the mobile core network 140 via the RAN 120.

[0057] The base units 121 may serve a number of remote units 105 within a serving area, for example, a cell or a cell sector, via a wireless communication link 123. The base units 121 may communicate directly with one or more of the remote units 105 via communication signals. Generally, the base units 121 transmit DE communication signals to serve the remote units 105 in the time, frequency, and/or spatial domain. Furthermore, the DL communication signals may be carried over the wireless communication links 123. The wireless communication links 123 may be any suitable carrier in licensed or unlicensed radio spectrum. The wireless communication links 123 facilitate communication between one or more of the remote units 105 and/or one or more of the base units 121. Note that during NR operation on unlicensed spectrum (referred to as “NR- U”), the base unit 121 and the remote unit 105 communicate over unlicensed (i.e., shared) radio spectrum.

[0058] In one embodiment, the mobile core network 140 is a 5G core (“5GC”) or an Evolved Packet Core (“EPC”), which may be coupled to a packet data network 150, like the Internet and private data networks, among other data networks. A remote unit 105 may have a subscription or other account with the mobile core network 140. In various embodiments, each mobile core network 140 belongs to a single mobile network operator (“MNO”) and/or Public Land Mobile Network (“PLMN”). The present disclosure is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol.

[0059] The mobile core network 140 includes several network functions (“NFs”). As depicted, the mobile core network 140 includes at least one UPF 141. The mobile core network 140 also includes multiple control plane (“CP”) functions including, but not limited to, an Access and Mobility Management Function (“AMF”) 143 that serves the RAN 120, a Session Management Function (“SMF”) 145, a Policy Control Function (“PCF”) 147, a Unified Data Management function (“UDM”) and a User Data Repository (“UDR”, also referred to as “Unified Data Repository”). Although specific numbers and types of network functions are depicted in Figure 1, one of skill in the art will recognize that any number and type of network functions may be included in the mobile core network 140.

[0060] The UPF(s) 141 is/are responsible for packet routing and forwarding, packet inspection, QoS handling, and external PDU session for interconnecting Data Network (“DN”), in the 5G architecture. The AMF 143 is responsible for termination of Non-Access Stratum (“NAS”) signaling, NAS ciphering & integrity protection, registration management, connection management, mobility management, access authentication and authorization, security context management. The SMF 145 is responsible for session management (i.e., session establishment, modification, release), remote unit (i.e., UE) Internet Protocol (“IP”) address allocation & management, DL data notification, and traffic steering configuration of the UPF 141 for proper traffic routing.

[0061] The PCF 147 is responsible for unified policy framework, providing policy rules to CP functions, access subscription information for policy decisions in UDR. The UDM is responsible for generation of Authentication and Key Agreement (“AKA”) credentials, user identification handling, access authorization, subscription management. The UDR is a repository of subscriber information and may be used to service a number of network functions. For example, the UDR may store subscription data, policy-related data, subscriber-related data that is permitted to be exposed to third party applications, and the like. In some embodiments, the UDM is colocated with the UDR, depicted as combined entity “UDM/UDR” 149.

[0062] In various embodiments, the mobile core network 140 may also include a Network Repository Function (“NRF”) (which provides Network Function (“NF”) service registration and discovery, enabling NFs to identify appropriate services in one another and communicate with each other over Application Programming Interfaces (“APIs”)), a Network Exposure Function (“NEF”) (which is responsible for making network data and resources easily accessible to customers and network partners), an Authentication Server Function (“AUSF”), or other NFs defined for the Fifth Generation Core network (“5GC”). When present, the AUSF may act as an authentication server and/or authentication proxy, thereby allowing the AMF 143 to authenticate a remote unit 105. In certain embodiments, the mobile core network 140 may include an authentication, authorization, and accounting (“AAA”) server.

[0063] In various embodiments, the mobile core network 140 supports different types of mobile data connections and different types of network slices, wherein each mobile data connection utilizes a specific network slice. Here, a “network slice” refers to a portion of the mobile core network 140 optimized for a certain traffic type or communication service. For example, one or more network slices may be optimized for enhanced mobile broadband (“eMBB”) service. As another example, one or more network slices may be optimized for ultra-reliable low- latency communication (“URLLC”) service. In other examples, a network slice may be optimized for machine-type communication (“MTC”) service, massive MTC (“mMTC”) service, Intemet- of-Things (“loT”) service. In yet other examples, a network slice may be deployed for a specific application service, a vertical service, a specific use case, etc.

[0064] A network slice instance may be identified by a single-network slice selection assistance information (“S-NSSAI”) while a set of network slices for which the remote unit 105 is authorized to use is identified by network slice selection assistance information (“NS SAI”). Here, “NSSAI” refers to a vector value including one or more S-NSSAI values. In certain embodiments, the various network slices may include separate instances of network functions, such as the SMF 145 and UPF 141. In some embodiments, the different network slices may share some common network functions, such as the AMF 143. The different network slices are not shown in Figure 1 for ease of illustration, but their support is assumed. [0065] While Figure 1 depicts components of a 5G RAN and a 5G core network, the described embodiments for resource-specific CSI reporting apply to other types of communication networks and RATs, including IEEE 802.11 variants, Global System for Mobile Communications (“GSM”, i.e., a 2G digital cellular network), General Packet Radio Service (“GPRS”), Universal Mobile Telecommunications System (“UMTS”), LTE variants, CDMA 2000, Bluetooth, ZigBee, Sigfox, and the like.

[0066] Moreover, in an LTE variant where the mobile core network 140 is an EPC, the depicted network functions may be replaced with appropriate EPC entities, such as a Mobility Management Entity (“MME”), a Serving Gateway (“SGW”), a PGW, a Home Subscriber Server (“HSS”), and the like. For example, the AMF 143 may be mapped to an MME, the SMF 145 may be mapped to a control plane portion of a PGW and/or to an MME, the UPF 141 may be mapped to an SGW and a user plane portion of the PGW, the UDM/UDR 149 may be mapped to an HSS, etc.

[0067] In various embodiments, the remote units 105 may communicate directly with each other (e.g., device-to-device communication) using sidelink communication signals 115. Here, sidelink transmissions may occur on sidelink resources. As discussed above, a remote unit 105 may be provided with different sidelink communication resources for different allocation modes. Mode-1 corresponds to a NR-based network-scheduled sidelink communication mode, wherein the in-coverage RAN 120 indicates resources for use in sidelink operation, including resources of one or more resource pools. Mode-2 corresponds to a NR-based UE-scheduled sidelink communication mode (i.e., UE-autonomous selection), where the remote unit 105 select a resource pools and resources therein from a set of candidate pools. Mode-3 corresponds to an LTE-based network-scheduled sidelink communication mode. Mode-4 corresponds to an LTE-based UE- scheduled sidelink communication mode (i.e., UE-autonomous selection). Note that 3GPP Rel- 16 specification does not allow remote units 105 to send multiple CSI triggers with overlapping CSI report windows in a given unicast session.

[0068] In the following descriptions, the term “RAN node” is used for the base station/ base unit, but it is replaceable by any other radio access node, e.g., gNB, ng-eNB, eNB, Base Station (“BS”), Access Point (“AP”), etc. Additionally, the term “UE” is used for the mobile station/ remote unit, but it is replaceable by any other remote device, e.g., remote unit, MS, ME, etc. Further, the operations are described mainly in the context of 5G NR. However, the below described solutions/methods are also equally applicable to other mobile communication systems for resource-specific CSI reporting. [0069] Figure 2A depicts an example timeline 200 showing association between a CSI trigger and corresponding CSI report reception. In this disclosure, the Tx UE 205 represents the UE triggering the CSI report and the Rx UE 210 represents the UE calculating/measuring and transmitting the CSI report. Note that the Tx UE 205 and Rx UE 210 may be embodiments of the remote unit 105 that perform sidelink communication.

[0070] As depicted, the Tx UE 205 is configured with separate resource pools for CSI reporting. At a first time, the Tx UE 205 uses the first Resource Pool (“Resource Pool #1”) to send a first CSI trigger 215 to the Rx UE 210. The Rx UE 210 generates a CSI report associated with the first resource pool, e.g., based on received SL CSI-RS (see block 220). After a first amount of time (i.e., CSI report latency), the Tx UE 205 receives a first CSI report 225 from the Rx UE 210. Between the time the first CSI trigger 215 is sent and the time the first CSI report 225 is received, there is pending reception of a CSI report for the first resource pool.

[0071] At a second time, the Tx UE 205 uses the second Resource Pool (“Resource Pool #2”) to send a second CSI trigger 230 to the Rx UE 210. The Rx UE 210 generates a CSI report associated with the second resource pool, e.g., based on received SL CSI-RS (see block 235). After a second amount of time (i.e., CSI report latency), the Tx UE 205 receives a second CSI report 240 from the Rx UE 210. Between the time the second CSI trigger 230 is sent and the time the second CSI report 240 is received, there is pending reception of a CSI report for the second resource pool.

[0072] In various embodiments, the Tx UE 205 uses Resource pool specific (“RP- specific”) CSI report triggering for the transmission and processing of multiple CSI triggers. In such embodiments, there is an association of the CSI trigger to a resource pool, separate CSI triggers may be transmitted for each resource pool when there is no pending reception of CSI report for that resource pool.

[0073] As used herein, a “resource pool” refers to a set of resources assigned for sidelink operation. A resource pool consists of a set of resource blocks (i.e., Physical Resource Blocks (“PRB”)) over one or more time units (e.g., subframe, slots, OFDM symbols). In some embodiments, the set of resource blocks comprises contiguous PRBs in the frequency domain. As used herein, a PRB refers to twelve consecutive subcarriers in the frequency domain. In certain embodiments, a UE may be configured with separate transmission resource pools (“Tx RPs”) and reception resource pools (“Rx RPs”), where the Tx RP of one UE is associated with an Rx RP of another UE to enable sidelink communication.

[0074] Figure 2B depicts one example of a Sidelink CSI Reporting MAC CE 250, according to embodiments of the disclosure. The Sidelink CSI Reporting MAC CE is identified by a MAC subheader with Logical Channel Identifier (“LCID”). In one embodiment, the MAC header and LCID are as specified in 3GPP Technical Specification (“TS”) 38.321. In one embodiment, the priority of the Sidelink CSI Reporting MAC CE is fixed to T. The Sidelink CSI Reporting MAC CE is defined as follows:

[0075] RI: This field indicates the derived value of the Rank Indicator (“RI”) for sidelink CSI reporting, e.g., as specified in clause 8.5 of 3GPP TS 38.214. The length of the field is 1 bit.

[0076] CQI: This field indicates the derived value of the Channel Quality Indicator (“CQI”) for sidelink CSI reporting, e.g., as specified in clause 8.5 of 3GPP TS 38.214. The length of the field is 4 bit.

[0077] R: Reserved bit, set to 0.

[0078] Described herein are procedures for transmission and processing of multiple CSI triggers using RP-specific CSI report triggers and the association of a CSI trigger to that of a resource pool, where each CSI trigger can be transmitted for a resource pool when there is no pending reception of a CSI report for that resource pool. Accordingly, the Tx UE may send a second CSI trigger associated with a second resource pool, while there is pending reception of a CSI report for a first resource pool, the first resource pool being separate from the second resource pool.

[0079] Described herein are procedures and signaling enhancements for the creation of association between transmitted aperiodic CSI trigger and the reported CSI values. In certain embodiments, the LCP procedure may be used for prioritizing the transmission of multiple CSI reports. Described herein are procedures and signaling enhancements for the transmission of periodic CSI-RS and aperiodic CSI trigger for the reporting averaged CQI values.

[0080] Described herein are procedures and signaling enhancements for activating/deactivating periodic CSI-RS transmission in a CG resource period and periodic CSI trigger at the end of the CG period. Described herein are procedures for the transmission of multiple CSI trigger and the association of the CSI trigger to that of a beam/panel, where each CSI trigger may be transmitted for a beam/panel when there is no pending reception of CSI report for that beam/panel.

[0081] According to embodiments of the first solutions, a Tx UE may use resource pool specific CSI report triggers for the transmission of multiple CSI trigger processing, where there is an association between a CSI trigger and corresponding CSI report to a resource pool. Accordingly, the Tx UE may transmit a plurality of trigger for aperiodic CSI reporting request and receive corresponding CSI report for each of the configured resource pools separately. As described above, unless an ongoing CSI report reception corresponding to a resource pool is already pending, the Tx UE may trigger an aperiodic CSI report for the resource pool.

[0082] Figure 3 depicts one association 300 between CSI trigger and CSI report reception. As depicted, the Tx UE 205 is configured with separate resource pools for CSI reporting. At a first time, the Tx UE 205 uses the first Resource Pool (“Resource Pool #1”) to send a first CSI trigger 305 to the Rx UE 210. The Rx UE 210 generates a CSI report associated with the first resource pool, e.g., based on received SL CSI-RS (see block 310).

[0083] As an example, if there is no pending CSI report reception for the second Resource Pool (“Resource Pool #2”), then the Tx UE 205 may also transmit a second CSI trigger 320 to request an aperiodic CSI report 330 for the second resource pool without waiting for the reception of CSI report 315 corresponding to the first aperiodic CSI request 305 triggered for the first resource pool. The Rx UE 210 generates the second CSI report 330 associated with the second resource pool, e.g., based on received SL CSI-RS (see block 325).

[0084] After a first amount of time (i.e., CSI report latency), the Tx UE 205 receives a first CSI report 315 from the Rx UE 210. Between the time the first CSI trigger 305 is sent and the time the first CSI report 315 is received, there is pending reception of a CSI report for the first resource pool. After a second amount of time (i.e., CSI report latency), the Tx UE 205 receives the second CSI report 330 from the Rx UE 210. Between the time the second CSI trigger 320 is sent and the time the second CSI report 330 is received, there is pending reception of a CSI report for the second resource pool.

[0085] In another related embodiment, each resource pool may map to a non-overlapping sub-channel (or set of non-overlapping sub-channels). Here, the Tx UE 205 may transmit a plurality of trigger for aperiodic CSI reporting request and receive corresponding CSI report for each of the non-overlapping sub-channel(s) separately for which an ongoing CSI report reception in a sub-channel is not pending. For example, the Tx UE 205 may transmit a second trigger for aperiodic CSI report for sub-channel #2 if there is no pending CSI report reception for sub-channel #2 without waiting for the reception of CSI report corresponding to a first aperiodic CSI request triggered for sub-channel # 1.

[0086] In one embodiment of the first solution, the Tx UE 205 may determine to transmit a second trigger 320 for aperiodic CSI reporting before the ongoing completion of the CSI report 315 for the first resource pool and/or sub-channel only when the associated priority level of the second CSI report trigger is higher than the first CSI report trigger.

[0087] In one implementation, the information element (“IE”) sl-LatencyBound-CSI- Report that configures (i.e., specifies) the CSI report latency in a PC5-RRC connection may additionally include fields to configure/indicate CSI latency bound per Resource Pool. Additionally, or alternatively, the sl-LatencyBound-CSI-Report may include fields to configure a SCI priority for the PC5 RRC connection.

[0088] In another implementation, the configuration of sl-LatencyBound-CSI-Report may specify a common CSI report latency that to be configured commonly across multiple Resource Pools. Additionally, or alternatively, the sl-LatencyBound-CSI-Report may specify a common SCI priority for a PC5 RRC connection.

[0089] In certain embodiments, the priority level of the CSI report trigger is associated with the CSI report quantities. For example, if a CSI report can be configured to report different combinations of quantities including Channel Quality Indicator (“CQI”), Rank Indicator (“RI”), Layer- 1 Reference Signal Received Power (“Ll-RSRP”), CSI-RS Resource ID (“CRT), then the priority may depend on what combinations of this quantities are to be reported. One combination may take precedence.

[0090] In some embodiments, the Rx UE 210 may be configured with plurality of sl-CSI- ReportTimer, where each sl-CSI-ReportTimer is maintained per resource pool. Here, the starting and stopping of the sl-CSI-ReportTimer are separately specified per CSI trigger per resource pool. As one example, a timer may be started when a Rx UE 210 receives a corresponding CSI trigger from Tx UE 205 for a particular Resource Pool and stopped after the successful transmission of CSI report to the Tx UE 205 corresponding to that trigger.

[0091] Similarly, the Tx UE 205 can be configured and maintained with a SL CSI report event per CSI trigger per resource pool. The Tx UE 205 can be configured with the maximum parallel CSI trigger considering all resource pool. Because there are multiple CSI triggers and CSI reports, indicating an association between aperiodic CSI request trigger and CSI reporting may be based on one or more of the following:

[0092] Option 1: The SL CSI Report MAC CE may additionally report Resource Pool Identifies (“ID”) and/or Sub-channel ID for which the CSI measurement was performed otherwise Resource Pool ID and/or Sub-channel ID for which CSI trigger and/or CSI-RS was received. As depicted in Figure 2B, the MAC CE contains a CSI report, i.e., CQI value (4 bit) and RI value (1 bit) and one of the reserved values in the MAC CE for CSI may be used for reporting Resource Pool ID and/or Sub-channel ID(s). In certain embodiments, the number of bits allocated for Resource Pool Index depends on the number of the resource pools supported and/or the number of bits allocated for Sub-channel Index depends on the maximum number of sub-channels supported.

[0093] Option 2: The Tx UE 205 may additionally indicate in the SCI along with the aperiodic CSI trigger, Resource Pool ID to be used for the transmission of CSI report by the Rx UE 210. Here, the Rx UE 210 performs Mode 1 resource allocation (i.e., network-scheduled mode) or Mode 2 resource allocation (i.e., UE-autonomous selection) on the indicated resource pool for the transmission of the CSI reports. In one embodiment, the number of bits allocated for Resource Pool Index depends on the number of the Resource Pools supported and may be signaled as part of a second SCI.

[0094] Option 3: The Tx UE 205 may indicate a trigger index or a sequence number in the SCI along with the aperiodic CSI trigger and then the Rx UE 210 may additionally include the trigger index or a sequence number along with the CSI report to associate the aperiodic CSI trigger with the CSI report. In one embodiment, the number of bits allocated fortrigger index or sequence depends on the number of multiple CSI trigger that can be ongoing before the completion of the earlier triggered CSI reports and the index or sequence number may be signaled as part of 2nd SCI.

[0095] Option 4: The Rx UE 210 may additionally include in the CSI report MAC CE, the sidelink slot index or slot offset of the received CSI trigger to associate the aperiodic CSI trigger with the transmission of CSI report. The sidelink slot index may represent physical sidelink slot or the logical sidelink slot related that of the resource pool configuration.

[0096] In some embodiments of the first solution, if the Rx UE 210 must transmit a plurality of CSI report (i.e., in response to multiple received CSI triggers from Tx UE 205), then Logical Channel (“LCH”) restriction at the Rx UE 210 may allow selection of a distinct resource pool for the transmission of CSI reports. Here, the Logical Channel Prioritization (“LCP”) procedure at the Rx UE 205 may prioritize the transmission of plurality of CSI report according to one of the following:

[0097] Option 1: The Rx UE 210 may prioritize the selection and transmission of CSI reports according to the configured latency bound so that lower latency is prioritized.

[0098] Option 2: The Rx UE 210 may prioritize the selection and transmission of CSI reports according to the indicated priority value in the SCI when the trigger was transmitted, in other words priority of the corresponding data channel.

[0099] Option 3: The Rx UE 210 may prioritize the selection and transmission of CSI reports according to the priority of the resource pool.

[0100] Option 4: A priority may also be configured for each CSI request/ report index.

[0101] In some embodiments, multiple CSI triggering may be enabled in a separate UE dedicated configuration.

[0102] According to embodiments of the second solution, the aperiodic CSI report triggering considers a plurality of CSI-RS occasions. In various embodiments, the Tx UE 205 indicates a start and stop of CSI-RS transmission to the Rx UE 210. The Rx UE 210 measures the transmited CSI-RS(s). When the Rx UE 210 receives an aperiodic trigger from the Tx UE 205, it averages the CSI measurements of the transmited CSI-RS(s).

[0103] In one implementation, the Tx UE 205 may transmit periodic CSI-RS within a PSSCH resource. Note that the activation of the transmission of periodic CSI-RS within the PSSCH may be indicated to the Rx UE/destination ID using a MAC CE. In this implementation, the Tx UE 205 may separately transmit an aperiodic CSI trigger, e.g., in a SCI, the Rx UE 210 to transmit a CSI report considering plurality of CSI-RS occasions.

[0104] Figure 4A depicts a first example timeline 400 for periodic CSI-RS and aperiodic CSI Trigger, according to embodiments of the disclosure. Upon activating the transmission of periodic CSI-RS (e.g., within the PSSCH), the Tx UE 205 transmits CSI-RS in a series of four CSI-RS occasions 405. As depicted, the Tx UE 205 separately transmits an aperiodic CSI Trigger 410 after the last CSI-RS occasion, enabling the Rx UE 210 to transmit a CSI report 415 considering the plurality of CSI-RS occasions 405. The Rx UE 210 averages the CSI measurements of the periodic CSI-RSs and transmits the CSI Report 415 to the Tx UE 205. The CSI Report latency refers to the interval between transmission of the CSI Trigger 410 and reception of the CSI Report 415.

[0105] Figure 4B depicts a second example timeline 420 for periodic CSI-RS and aperiodic CSI Trigger, according to embodiments of the disclosure. Upon activating the transmission of periodic CSI-RS (e.g., within the PSSCH), the Tx UE 205 transmits CSI-RS in a series of five CSI-RS occasions 425. As depicted, the Tx UE 205 separately transmits an aperiodic CSI Trigger 430 together with the last CSI-RS occasion, enabling the Rx UE 210 to transmit a CSI report 415 considering the plurality of CSI-RS occasions. The Rx UE 210 averages the CSI measurements of the periodic CSI-RSs and transmits the CSI Report 415 to the Tx UE 205. The CSI Report latency refers to the interval between transmission of the CSI Trigger 430 and reception of the CSI Report 415.

[0106] In one implementation of the second solution, a one-bit indicator in the MAC CE may activate the periodic CSI-RS configuration and the Rx UE 210 expects to receive a CSI-RS after a specific number of slots. For example, the Rx UE 210 may expect to receive CSI-RS N+K slots after the reception of the MAC CE activation indicator in slot N, where K represents the offset between the activating MAC CE and the first CSI-RS.

[0107] In one implementation, the Tx UE 205 may use a MAC CE to explicitly deactivate the transmission/reception of CSI-RS. In another implementation, the aperiodic SCI trigger implicitly deactivates the transmission/reception of CSI-RS. In this implementation, the Rx UE 210 does not expect to receive periodic CSI-RS after the reception of the aperiodic CSI trigger in the SCI unless it is activated again, e.g., using a MAC CE.

[0108] In another implementation, the CSI report contains an CQI/RI value that represents the average CQI/RI value that is calculated across multiple CSI-RS occasions. In one example, the Rx UE 210 may be configured that the CSI report is based on last M number of CSI-RS transmissions. In a further implementation, the CSI report includes different quantities, such as average value over last AT CSI-RS transmissions and/or the value of the latest CSI-RS transmission.

[0109] In another implementation, a one-bit indicator in the 2nd SCI may indicate the presence of CSI-RS in PSSCH, and this bit is configured such that the presence of CSI-RS in PSSCH may be indicated to the Rx UE 210 (e.g., destination ID) separately from that of the CSI report request bit.

[0110] In certain embodiments, the CSI report may contain an averaged CQURI value per sub-channel from the CSI-RS transmitted from multiple sub-channels. In one implementation, the CSI report may additionally indicate the sub-channel index for which the averaged CQURI is reported. In another implementation, the CSI trigger may implicitly (or explicitly) indicate the sub-channel index for which the CSI report is requested considering multiple transmitted CSI-RS. Here, the sub-channel index may be implicitly determined from the (lowest) sub-channel of SCI carrying the CSI trigger.

[0111] Figure 5 depicts one example 500 of SL Configured Grant (“CG”), according to embodiments of the disclosure. In various embodiments, the Tx UE 205 may be allocated SL resources semi-persistently by means of a SL configured grant. Similar to the NR Uu interface, on the SL interface there may be two types of configured grants, Type 1 and Type 2 Configured Grant. SL resources are allocated with a given configured periodicity, i.e., also referred to as period. Up to three CG resources can be allocated by the gNB within each period of SL configured grant. The Hybrid Automatic Repeat Request (“HARQ”) process ID (“HPID”) for each transmission in a SL resource corresponding to a SL configured grant is determined, e.g., based on the formula used for UL configured grants as described in 3GPP TS 38.321. As used herein, “HARQ-ACK” may represent collectively the Positive Acknowledge (“ACK”) and the Negative Acknowledge (“NACK”) and Discontinuous Transmission (“DTX”). ACK means that a Transport Block (“TB”) is correctly received while NACK (or NAK) means a TB is erroneously received and DTX means that no TB was detected.

[0112] As depicted, in the first SL CG period (“Period 1”) three CG resources are allocated for a first HARQ process, having HPID “HP1”. In the second SL CG period (“Period 2”) three CG resources are allocated for a second HARQ process, having HPID “HP2”. In the third SL CG period (“Period 3”) three CG resources are allocated for the first HARQ process (i.e., HP1). Each transmission of SL CG resources is associated with a Physical Sidelink Feedback Channel (“PSFCH”) transmission opportunity (i.e., for SL HARQ feedback). After each CG resource, the Rx UE 210 reports SL HARQ feedback to the Tx UE 205, e.g., indicating whether the transmission was successful or not. After the last CG resource within a SL CG period there is a Physical Uplink Control Channel (“PUCCH”) transmission opportunity for the Tx UE 205 to report sidelink HARQ to the network (i.e., gNB), e.g., indicating whether the transmission was successful or not.

[0113] Figure 6 shows an example of a timeline 600 for CSI-RS occasions and CSI reporting. According to embodiments of the third solution, the Tx UE 205 may configure and activate the periodic CSI-RS transmission within a SL Configured Grant (“CG”) resource period. In one embodiment, the CSI-RS may be configured to be transmitted in each of the SL CG resources. In another embodiment, the CSI-RS may be configured to be transmitted in one of the CG resources in a period, such as the last CG resource of a period. In other embodiments, the Tx UE 205 may be configured with a separate CG resource for the purpose of periodic CSI reporting. In one implementation, a fourth CG resource at the end of the period is defined for the purpose of periodic CSI reporting. In another implementation, the last CG resource of a period is defined for the CSI report transmission.

[0114] In one implementation, activation/deactivation of CSI-RS transmission and/or CSI report transmission for the next period is defined using a MAC CE or SCI in one of the previous period, where the activation/deactivation message may be transmitted one of the CG resources in a period or last CG resource of a period.

[0115] According to embodiments of the fourth solution, a Rx UE 210 may generate CSI reports for multiple antenna panels and/or beams and/or spatial filter. As used herein, the term “beam/panel/spatial-filter” (or similar notation) indicates that the description applies to an antenna panel and/or beam. In some embodiments, the Tx UE 205 may transmit a Beam-specific CSI trigger, wherein the association of the CSI trigger to the CSI report is per beam, or antenna panel, or spatial filter.

[0116] The Tx UE 205 may transmit plurality of trigger for aperiodic CSI reporting request and receive corresponding CSI reports for each of the beam/panel/spatial-filter separately. Similar to the separate resource pools described above in the first solution, the Tx UE 205 may independently transmit the plurality of trigger for aperiodic CSI reporting request and receive corresponding CSI report for each of the configured beam/panel/spatial-filter. As described above, unless an ongoing CSI report reception corresponding to a beam/panel/spatial-filter is already pending, the Tx UE 205 may trigger an aperiodic CSI report for the beam/panel/spatial-filter. The MAC CE containing the CSI report includes Ll-RSRP of the beam and the corresponding CSI-RS Resource ID (“CRT).

[0117] In one implementation, the beam/panel/spatial -filter may be associated with a resource pool and the Rx UE 210 may be configured to measure CSI-RS on the all the configured resource pools, but report only corresponding to best /V beams (i.e., resource pool) that have the highest Ll-RSRP. In one implementation CSI report trigger with Ll-RSRP is always prioritized over other CSI report trigger.

[0118] Regarding the measurement-and-reporting procedure, a CSI request may contain a request for CSI reporting for multiple Resource Pools, Sub-channel(s), Sub-channel Set(s). The Tx UE 205 may determine a need for CSI measurements, e.g., to better schedule the Rx UE 210, particularly for multiple resources (e.g., Resource Pools, Sub-channels, beam/panel/spatial-filter) and may according indicate this need in the CSI request. The Rx UE 210 then prepares to perform corresponding CSI measurements and send the report(s).

[0119] To this end, an RRC configuration may be used between the two concerned UEs (i.e., Tx UE 205 and Rx UE 210) to setup the latency of each report (corresponding to CSI request/ report index). Alternatively, the latency of each report may be associated to the Resource Pool (or Sub-channel(s)) used for requesting a CSI report. In such a scenario of prioritization of multiple CSI report may be implemented as described in the first solution. When prioritizing the multiple CSI reports, the Rx UE 210 considers the RRC Configured latency requirement of each report. For example, the CSI report that is closest in time in terms of latency (i.e., due soonest) will be reported first, then the next one, and so on.

[0120] If the latencies of two such reports are same, additional factors are considered. For example, in addition to the latency, a priority may also be configured for each CSI request/ report index or to a resource pool. Here, the configured priority may be used for conflict resolution between reports having the same latency or same deadline. Alternatively, the configured priority may be the primary factor for order of reporting, where the configured latency is used for conflict resolution between reports having the same priority.

[0121] In some embodiments, a new MAC CE is defined for the purpose for carrying multiple CSI reports and each MAC CE contains multiple CSI reports containing CSI reports from multiple RPs or beams or sub-channels, wherein each Resource Pool ID/Sub-Channel ID or a trigger index associates the CSI report to the CSI trigger is added after each CSI report. In certain embodiments, the new MAC CE may be defined for carrying N CSI reports where each CSI report can be defined as {CQI, RI, Ll-RSRP, CRI, Sub-channel ID, RP ID}. [0122] In another alternative options, a separate Scheduling Request (“SR”) may be configured for the purpose of requesting resource for the transmitting CSI reports. And in another option, a Buffer Status Report (“BSR”) or any control signaling (e.g., RRC, MAC CE, and/or Layer- 1 (“LI”) signaling) containing fields to report the size or number of the CSI reports to be transmitted.

[0123] In another alternative, the Rx UE 210 may multiplex multiple MAC CEs, wherein each MAC CE carries one CSI report. As another alternative, a truncated MAC CE and a full MAC CE can be used. Here, the truncated MAC CE only contains a limited number (i.e., less than maximum) of CSI reports. For example, the truncated MAC CE may contain just one CSI report. In contrast, the full MAC CE can carry up to a certain maximum number of CSI reports. In one embodiment, a truncated MAC CE carries up to one half of the maximum number of CSI reports, while the full MAC CE carries more than one half and up to the maximum number of CSI reports. In another embodiment, a truncated MAC CE carries less than one half of the maximum number of CSI reports, while the full MAC CE carries one half the maximum number of CSI reports or more.

[0124] When one or more CSI reports need to be sent, the Tx UE 205 will trigger a CSI report SR. Upon reception of the resulting grant, the UE may include a truncated MAC CE CSI Report if the grant is not sufficient to carry the full MAC CE CSI Report.

[0125] Another example, Multiple CSI reporting in a MAC CE may be enabled in a separate UE dedicated configuration or autonomously decided by the UE based on the pending of N CSI reports to a destination.

[0126] According to embodiments of the fifth solution, a set of sidelink UEs may perform inter-UE coordination of resources. When a set of resources determined at a first UE (i.e., UE-A ) is sent to UE-B in Resource Allocation mode 2 and UE-B takes this into account in the resource selection for its own transmission. For the definition of “a set of resources,” at least followings can be considered:

[0127] 1) Resource set which is preferred for UE-B’s transmission, e.g., Resource set which is preferred for UE-A’s reception or Resource set which is preferred for intended receiver(s) of UE-B’s transmission.

[0128] 2) Resource set which is preferred not to be used by UE-B’s transmission, e.g., Resource set which is not preferred for UE-A’s reception or Resource set with a problem for intended receiver(s) of UE-B’s transmission.

[0129] Figure 7A depicts an inter-UE coordination procedure 700, according to embodiments of the disclosure . Here, the UE-A 705 receives an explicit request 715 from the UE- B 710. Here, the explicit request message 715 triggers inter-UE coordination information transmission. The UE-A 705 generates an inter-UE coordination message 720 than contains a set of resources. The set of resources may be selected as described herein.

[0130] In one embodiment, the UE-B 710 can be a Tx UE 205 that triggers the request for the coordination message from the UE-A 705, where the UE-A 705 transmits the coordination message in response to the reception of the trigger message(i.e., request 715).

[0131] In various embodiments, a sidelink UE supporting inter-UE coordination (inter UE coordination message or UE assistance information) may be configured with a plurality of trigger and reporting options, where each of the trigger is specifically defined to request a report type from Rx UE(s) for a particular reason such as to solve half duplex, hidden node, periodic collision, etc.

[0132] In one implementation, a sidelink UE may be defined with a plurality of triggers and, as part of each trigger, the UE may request a specific information from the Peer UE such as requesting information on the Tx/Rx slots of the peer UEs (solve half duplex), Resource set which is preferred for UE-B’s transmission (hidden node), set of recommended resource set from a third UE to be used for the communication with UE-A/UE-B, Resource set which is preferred not to be used by UE-B’s transmission (hidden node), sub-band CQI measurements for plurality of subchannels in a resource pool.

[0133] Additional information may be transmitted along with the trigger indicating whether to report the past, future or both past/fiiture resources. Another additional information field, such as Minimum Communication Range (“MCR”), may be added to request the UEs within an indicated MCR to transmit the inter-UE coordination message considering groupcast/broadcast. Additionally, the Resource Pool ID, Beam ID, and/or CRI are reported as part of the set of resources.

[0134] In another implementation, each report type may be separately configured to be either periodic, aperiodic, and semi-persistent. Here, a UE is not expected to be configured with both aperiodic and periodic/semi-persistent reporting for the transmission of same type of report.

[0135] In another implementation, an aperiodic trigger may be transmitted using a MAC CE or a second SCI, and the Rx UE 210 may start a timer and an event for the after the reception of the aperiodic trigger. Here, the timer is stopped, and the event is cancelled after the transmission of the report. A latency is configured separately for transmission of each of the report and the latency value may be configured during PC5 RRC and specified in the SCI (or MAC CE) or defined according to the defined priority value or the priority value specified in SCI.

[0136] In one implementation, the triggering UE (i.e., Tx UE 205) is not allowed to trigger another aperiodic trigger for the same UE for the same report/information (as explained above) before the last slot of the expected reception or completion of the ongoing report associated with a received aperiodic trigger.

[0137] In another implementation, the triggering UE can trigger another aperiodic trigger for the same UE for the same report/information before the completion of the ongoing aperiodic trigger unless the trigger is for a different resource pools/beams (CRI)/sub-channels.

[0138] In another implementation, the triggering UE can trigger another (second) aperiodic trigger requesting for a report which is different from the ongoing trigger (first) for the same UE before the completion of the ongoing aperiodic trigger (first).

[0139] In one implementation, each of the report may be associated with a different MAC CE, and the priority and latency of each report may be individually configured in PC5 RRC, MAC CE, and/or SCI. The LCP may prioritize the transmission of plurality of reports considering the latency bound and/or priority values as described above. In various embodiments, each report may be transmitted in a distinct resource pool. In certain embodiments, multiple CSI reports are multiplexed into a single MAC CE. Alternatively, multiple MAC CEs may be transmitted, where each MAC CE contains one report.

[0140] After the reception of the trigger and/or additional information such as request for past and/or future resource, the Rx UE 210 may perform different behaviors. In one implementation, the Rx UE 210 may report a set of resources that was not previously decoded or for which a NACK was previously sent. Alternatively, the Rx UE 210 may report a set of resources that was previously decoded successful or for which an ACK was previously sent and does not expect transmission in those resource soon which can be for ‘X’ ms/slots. In another implementation, the trigger may explicitly or implicitly contain information whether the receiving user (i.e., Rx UE 210) may perform sensing, or candidate resource exclusion, or selection for the transmission of set of resources.

[0141] Referring again to Figure 6, the Rx UE 210 may be configured for the periodic transmission of the certain report type within the configured grant (“CG”) resource period. In some embodiments, the Rx UE 210 may be configured with a separate CG resource. For example, a fourth CG resource at the end of the period may be defined for the purpose of periodic reporting or last CG resource of a period is defined for the report transmission. After receiving the CSI report, the Tx UE 205 may decide to transmit the data in the next period to a certain UE/destination. In another implementation, above report may be multiplexed along with the CSI report in the same MAC CE or MAC CEs containing CSI report and coordination report may be multiplexed together in the same TB. [0142] In one implementation, activation/deactivation of report type for the next period is defined using a MAC CE or SCI or PC5 RRC (depending on the cast type) in one of the previous period, where the activation/deactivation message may be transmitted one of the CG resources in a period or last CG resource of a period.

[0143] In some embodiments, the Rx UE 210 may report sub-band CQI of reporting quantized SINR or Reference Signal Received Power (“RSRP”) or Received Signal Strength Indicator (“RSSI”) in each sub-channel or configured set of sub-channels. In certain embodiments, the UE may autonomously select the M sub-channels to be reported from N sub-channels based on the type of received trigger (preferred or not preferred resources) and the UE may autonomously select the resource pool for the transmission of the set of resource or sub-band CQI as explained above. In another implementation, the UE may be requested to inform the preferred or not preferred set of resources in an indicated resource pool/beam.

[0144] In one implementation, the Rx UE 210 may report different report type in each of the CG resource in a period. In another implementation, the Rx UE 210 is configured to report same report type in each period.

[0145] Figure 7B depicts a PC5 protocol stack 750, according to embodiments of the disclosure. While Figure 7B shows the UE-A 705 and the UE-B 710, these are representative of a set of UEs communicating peer-to-peer via PC5 and other embodiments may involve different UEs, such as the Tx UE 205 and the Rx UE 210. As depicted, the PC5 protocol stack includes a physical (“PHY”) layer 755, a Media Access Control (“MAC”) sublayer 760, a Radio Link Control (“RLC”) sublayer 765, a Packet Data Convergence Protocol (“PDCP”) sublayer 770, and Radio Resource Control (“RRC”) and Service Data Adaptation Protocol (“SDAP”) layers (depicted as combined element “RRC/SDAP” 775), for the control plane and user plane, respectively.

[0146] The AS protocol stack for the control plane in the PC5 interface consists of at least RRC, PDCP, RLC and MAC sublayers, and the physical layer. The AS protocol stack for the user plane in the PC5 interface consists of at least SDAP, PDCP, RLC and MAC sublayers, and the physical layer. The Layer- 1 (“LI”) comprises the PHY layer 755. The Layer-2 (“L2”) is split into the SDAP, PDCP, RLC and MAC sublayers. The Layer-3 (“L3”) includes the RRC sublayer and the NAS layer for the control plane and includes, e.g., an IP layer for the user plane. LI and L2 are referred to as “lower layers”, while L3 and above (e.g., transport layer, Vehicle-to-Everything (“V2X”) layer, application layer) are referred to as “higher layers” or “upper layers.”

[0147] Regarding triggering of SL CSI reports, according to Rel-16 the CSI-triggering UE is not allowed to trigger another aperiodic CSI report for the same UE before the last slot of the expected reception or completion of the ongoing aperiodic CSI report associated with the SCI format 2-A with the "CSI request" field set to 1. Here, the last slot of the expected reception of the ongoing aperiodic CSI report is given by 3GPP TS 38.321.

[0148] Regarding, SL Grant reception, if the MAC entity has selected to create a selected sidelink grant corresponding to transmission(s) of a single MAC PDU, and if SL data is available in a logical channel, or a Sidelink Channel State Information (“SL-CSI”) reporting is triggered. If a SL-CSI reporting is triggered, the Tx UE 205 selects any pool of resources among the pools of candidate resources (i.e., resource pools). In certain embodiments, the UE may perform the transmit resource (re-)selection check on the selected pool of resources, e.g., as specified in clause 5.22.1.2 of 3GPP TS 38.321.

[0149] Regarding CSI reporting, the SL-CSI reporting procedure is used to provide a peer UE with sidelink channel state information, e.g., as specified in clause 8.5 of 3GPP TS 38.214. The RRC layer may configure a sl-LatencyBound-CSI-Report parameter to control the SL-CSI reporting procedure. Here, the sl-LatencyBound-CSI-Report is maintained for each PC5-RRC connection.

[0150] Regarding CSI-RS transmission procedure a UE transmits sidelink CSI-RS within a unicast PSSCH transmission if the following conditions hold: A) CSI reporting is enabled by higher layer parameter sl-CSI-Acquisitiorr, and B) the "CSI request" field in the corresponding SCI format 0-2 is set to 1.

[0151] The following parameters for CSI-RS transmission are configured via the higher layer parameter for each CSI-RS configuration: A) nrofPortsCSIRS-SL indicates the number of ports for SL CSI-RS; B) firstSymbolInTimeDomainCSIRS-SL indicates the first Orthogonal Frequency Division Multiplexing (“OFDM”) symbol in a Physical Resource Block (“PRB”) used for SL CSI-RS; and C) frequDomainAllocationCSIRS-SL indicates the frequency domain allocation for SL CSI-RS.

[0152] Regarding Reporting configurations, the UE is to calculate CSI parameters (if reported) assuming the following dependencies between CSI parameters (if reported). CQI is to be calculated conditioned on the reported RI.

[0153] Regarding triggering of sidelink CSI reports, the CSI-triggering UE is not allowed to trigger another aperiodic CSI report for the same UE before the last slot of the expected reception or completion of the ongoing aperiodic CSI report associated with the SCI format 2-A with the "CSI request" field set to 1, where the last slot of the expected reception of the ongoing aperiodic CSI report is given by TS 38.321. An aperiodic CSI report is triggered by an SCI format 2-A with the "CSI request" field set to 1. [0154] Also regarding CSI reporting, the UE may be configured with one CSI reporting latency bound as indicated by the higher layer parameter sl-LatencyBound-CSI-Report . CSI reporting is aperiodic. Such parameter may be as described in 3GPP TS 38.321. As described above with reference to Figure 2B, the Rx UE 210 reports SL CSI via MAC CE (with one OCTET) identified by new LCID. Here it is assumed a 1 -bit RI and single 4-bits for CQI based on Uu. CSI reporting MAC CE report is triggered by indication from lower layer.

[0155] Figure 8 depicts a user equipment apparatus 800 that may be used for resourcespecific CSI reporting, according to embodiments of the disclosure. In various embodiments, the user equipment apparatus 800 is used to implement one or more of the solutions described above. The user equipment apparatus 800 may be one embodiment of the remote unit 105, the Tx UE 205, the Rx UE 210, the UE-A 705, and/or the UE-B 710, described above. Furthermore, the user equipment apparatus 800 may include a processor 805, a memory 810, an input device 815, an output device 820, and a transceiver 825.

[0156] In some embodiments, the input device 815 and the output device 820 are combined into a single device, such as a touchscreen. In certain embodiments, the user equipment apparatus 800 may not include any input device 815 and/or output device 820. In various embodiments, the user equipment apparatus 800 may include one or more of: the processor 805, the memory 810, and the transceiver 825, and may not include the input device 815 and/or the output device 820.

[0157] As depicted, the transceiver 825 includes at least one transmitter 830 and at least one receiver 835. In some embodiments, the transceiver 825 communicates with one or more cells (or wireless coverage areas) supported by one or more base units 121. In various embodiments, the transceiver 825 is operable on unlicensed spectrum. Moreover, the transceiver 825 may include multiple UE panels supporting one or more beams. Additionally, the transceiver 825 may support at least one network interface 840 and/or application interface 845. The application interface(s) 845 may support one or more APIs. The network interface(s) 840 may support 3GPP reference points, such as Uu, Nl, PC5, etc. Other network interfaces 840 may be supported, as understood by one of ordinary skill in the art.

[0158] The processor 805, in one embodiment, may include any known controller capable of executing computer-readable instructions and/or capable of performing logical operations. For example, the processor 805 may be a microcontroller, a microprocessor, a central processing unit (“CPU”), a graphics processing unit (“GPU”), an auxiliary processing unit, a field programmable gate array (“FPGA”), or similar programmable controller. In some embodiments, the processor 805 executes instructions stored in the memory 810 to perform the methods and routines described herein. The processor 805 is communicatively coupled to the memory 810, the input device 815, the output device 820, and the transceiver 825.

[0159] In various embodiments, the processor 805 controls the user equipment apparatus 800 to implement the above described UE behaviors. In certain embodiments, the processor 805 may include an application processor (also known as “main processor”) which manages application-domain and operating system (“OS”) functions and a baseband processor (also known as “baseband radio processor”) which manages radio functions.

[0160] In various embodiments, the processor 805 transmits (i.e., via the transceiver 825 implementing a sidelink interface) a CSI-RS within a sidelink data region (e.g., PSSCH) and transmits a CSI request indicator in SCI, where the CSI request is associated with a first resource pool. Note that SCI may include 1 bit to indicate the CSI request (e.g., see SCI format 0-2).

[0161] Additionally, the processor 805 transmits an aperiodic CSI trigger corresponding to a second resource pool separate from the first resource pool. Via the transceiver 825, the processor 805 receives a first CSI report (e.g., using a MAC CE) in response to the CSI request and receives an aperiodic CSI report (e.g., using a MAC CE) in response to the aperiodic CSI trigger, where the aperiodic CSI trigger corresponding to the second resource pool is sent prior to receipt of the first CSI report.

[0162] In some embodiments, the processor 805 indicates an association of a resource pool to a transmitted aperiodic CSI trigger and corresponding CSI report. In certain embodiments, each CSI report (e.g., MAC CE) indicates a resource pool identifier for which CSI measurements were performed. In certain embodiments, the SCI indicates a resource pool identifier of the first resource pool to be used for the transmission of CSI report.

[0163] In certain embodiments, the SCI and the aperiodic CSI report (e.g., MAC CE) indicate one of: a trigger index and a sequence number. In certain embodiments, the aperiodic CSI report (e.g., MAC CE) includes one of: a slot index of the corresponding CSI trigger and slot offset of the corresponding CSI trigger. In some embodiments, the processor 805 maintains a separate report timer (e.g., si CSI-ReportTime ) for each resource pool.

[0164] In some embodiments, transmitting the CSI-RS includes transmitting a plurality of CSI-RSs over a plurality of CSI-RS occasions, where the aperiodic CSI report contains an averaged value (e.g., CQI/RI value) that is calculated over multiple CSI-RS occasions. In certain embodiments, the aperiodic CSI trigger is transmitted together with the last CSI-RS. In other embodiments, the aperiodic CSI trigger is transmitted is a separate SCI after with the last CSI-RS.

[0165] In some embodiments, the processor 805 configures a plurality of CSI report latency requirements (e.g., sl-LatencyBound-CSI-Report), each latency requirement being associated with a particular resource pool. In some embodiments, the processor 805 configures a plurality of CSI report latency requirements (e.g., sl-LatencyBound-CSI-Report), each latency requirement being associated with a particular priority value in SCI.

[0166] In some embodiments, the first and second resource pools include non-overlapping sub-channels. In some embodiments, the first resource pool is associated with a first priority and the second resource pool is associated with a second priority. In certain embodiments, the CSI trigger is sent prior to receipt of the first CSI report in response to the second priority being higher than the first priority. In some embodiments, a CSI report window of the first CSI report overlaps with a CSI report window of the aperiodic CSI report.

[0167] In some embodiments, the apparatus is allocated semi-persistent sidelink resources (e.g., SL CG) having a configured grant periodicity, where transmitting the CSI-RS includes transmitting within a semi-persistent sidelink resource (e.g., CG resource). In certain embodiments, the semi-persistent sidelink resource used for CSI-RS transmission is a separate configured grant resource. In certain embodiments, the first CSI report is received at the end of a configured grant period.

[0168] In various embodiments, the processor 805 receives (i.e., via the transceiver 825 implementing a sidelink interface) a CSI-RS within a sidelink data region (e.g., PSSCH) and receives a CSI request indicator in SCI, the CSI request associated with a first resource pool. The processor 805 receives receiving an aperiodic CSI trigger corresponding to a second resource pool and transmitting a first CSI report (e.g., using a MAC CE) in response to the CSI request, where the aperiodic CSI trigger corresponding to the second resource pool is received prior to sending the first CSI report. Via the transceiver 825, the processor 805 transmits an aperiodic CSI report (e.g., using a MAC CE) in response to the aperiodic CSI trigger, where a CSI report window of the first CSI report overlaps with a CSI report window of the aperiodic CSI report.

[0169] In some embodiments, the processor 805 performs an LCP procedure to prioritize transmission of a plurality of CSI reports when there are multiple CSI triggers concurrently pending for separate resource pools. In certain embodiments, each resource pool has a priority level, where the LCP procedure operates on the priority levels of the separate resource pools. In certain embodiments, each resource pool is associated with a specific latency requirement (i.e., latency bound), where the LCP procedure operates on the latency requirements of the separate resource pools.

[0170] In some embodiments, the transceiver 825 receives an indication of an association of a resource pool to a transmitted aperiodic CSI trigger and corresponding CSI report. In certain embodiments, each CSI report (e.g., MAC CE) indicates a resource pool identifier for which CSI measurements were performed. In certain embodiments, the SCI indicates a resource pool identifier of the first resource pool to be used for the transmission of CSI report.

[0171] In certain embodiments, the SCI and the aperiodic CSI report (e.g., MAC CE) indicate one of: a trigger index and a sequence number. In certain embodiments, the aperiodic CSI report (e.g., MAC CE) includes one of: a slot index of the corresponding CSI trigger and slot offset of the corresponding CSI trigger.

[0172] In some embodiments, receiving the CSI-RS includes receiving a plurality of CSI- RSs over a plurality of CSI-RS occasions, where the aperiodic CSI report contains an averaged value (e.g., CGI/RI value) that is calculated over multiple CSI-RS occasions. In certain embodiments, the aperiodic CSI trigger is transmitted together with the last CSI-RS. In other embodiments, the aperiodic CSI trigger is transmitted is a separate SCI after with the last CSI-RS.

[0173] In some embodiments, the transceiver 825 receives a plurality of CSI report latency requirements (e.g., sl-LatencyBound-CSI-Report), each latency requirement being associated with a particular resource pool. In some embodiments, the transceiver 825 receives a plurality of CSI report latency requirements (e.g., sl-LatencyBound-CSI-Report), each latency requirement being associated with a particular priority value in SCI.

[0174] In some embodiments, the first and second resource pools include non-overlapping sub-channels. In some embodiments, the first resource pool is associated with a first priority and the second resource pool is associated with a second priority. In certain embodiments, the CSI trigger is sent prior to receipt of the first CSI report in response to the second priority being higher than the first priority.

[0175] In some embodiments, receiving the CSI-RS includes receiving within a semi- persistent sidelink resource (e.g., CG resource). In certain embodiments, the first CSI report is transmitted at the end of a configured grant period.

[0176] The memory 810, in one embodiment, is a computer readable storage medium. In some embodiments, the memory 810 includes volatile computer storage media. For example, the memory 810 may include a RAM, including dynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and/or static RAM (“SRAM”). In some embodiments, the memory 810 includes non-volatile computer storage media. For example, the memory 810 may include a hard disk drive, a flash memory, or any other suitable non-volatile computer storage device. In some embodiments, the memory 810 includes both volatile and non-volatile computer storage media.

[0177] In some embodiments, the memory 810 stores data related to resource-specific CSI reporting and/or mobile operation. For example, the memory 810 may store various parameters, panel/beam configurations, resource assignments, policies, and the like as described above. In certain embodiments, the memory 810 also stores program code and related data, such as an operating system or other controller algorithms operating on the apparatus 800.

[0178] The input device 815, in one embodiment, may include any known computer input device including a touch panel, a button, a keyboard, a stylus, a microphone, or the like. In some embodiments, the input device 815 may be integrated with the output device 820, for example, as a touchscreen or similar touch-sensitive display. In some embodiments, the input device 815 includes a touchscreen such that text may be input using a virtual keyboard displayed on the touchscreen and/or by handwriting on the touchscreen. In some embodiments, the input device 815 includes two or more different devices, such as a keyboard and a touch panel.

[0179] The output device 820, in one embodiment, is designed to output visual, audible, and/or haptic signals. In some embodiments, the output device 820 includes an electronically controllable display or display device capable of outputting visual data to a user. For example, the output device 820 may include, but is not limited to, a Liquid Crystal Display (“LCD”), a Light- Emitting Diode (“LED”) display, an Organic LED (“OLED”) display, a projector, or similar display device capable of outputting images, text, or the like to a user. As another, non-limiting, example, the output device 820 may include a wearable display separate from, but communicatively coupled to, the rest of the user equipment apparatus 800, such as a smart watch, smart glasses, a heads-up display, or the like. Further, the output device 820 may be a component of a smart phone, a personal digital assistant, a television, a table computer, a notebook (laptop) computer, a personal computer, a vehicle dashboard, or the like.

[0180] In certain embodiments, the output device 820 includes one or more speakers for producing sound. For example, the output device 820 may produce an audible alert or notification (e.g., a beep or chime). In some embodiments, the output device 820 includes one or more haptic devices for producing vibrations, motion, or other haptic feedback. In some embodiments, all or portions of the output device 820 may be integrated with the input device 815. For example, the input device 815 and output device 820 may form a touchscreen or similar touch-sensitive display. In other embodiments, the output device 820 may be located near the input device 815.

[0181] The transceiver 825 communicates with one or more network functions of a mobile communication network via one or more access networks. The transceiver 825 operates under the control of the processor 805 to transmit messages, data, and other signals and also to receive messages, data, and other signals. For example, the processor 805 may selectively activate the transceiver 825 (or portions thereof) at particular times in order to send and receive messages.

[0182] The transceiver 825 includes at least transmitter 830 and at least one receiver 835. One or more transmitters 830 may be used to provide UL communication signals to a base unit 121, such as the UL transmissions described herein. Similarly, one or more receivers 835 may be used to receive DL communication signals from the base unit 121, as described herein. Although only one transmitter 830 and one receiver 835 are illustrated, the user equipment apparatus 800 may have any suitable number of transmitters 830 and receivers 835. Further, the transmitter(s) 830 and the receiver(s) 835 may be any suitable type of transmitters and receivers. In one embodiment, the transceiver 825 includes a first transmitter/receiver pair used to communicate with a mobile communication network over licensed radio spectrum and a second transmitter/receiver pair used to communicate with a mobile communication network over unlicensed radio spectrum.

[0183] In certain embodiments, the first transmitter/receiver pair used to communicate with a mobile communication network over licensed radio spectrum and the second transmitter/receiver pair used to communicate with a mobile communication network over unlicensed radio spectrum may be combined into a single transceiver unit, for example a single chip performing functions for use with both licensed and unlicensed radio spectrum. In some embodiments, the first transmitter/receiver pair and the second transmitter/receiver pair may share one or more hardware components. For example, certain transceivers 825, transmitters 830, and receivers 835 may be implemented as physically separate components that access a shared hardware resource and/or software resource, such as for example, the network interface 840.

[0184] In various embodiments, one or more transmitters 830 and/or one or more receivers 835 may be implemented and/or integrated into a single hardware component, such as a multitransceiver chip, a system -on-a-chip, an Application-Specific Integrated Circuit (“ASIC”), or other type of hardware component. In certain embodiments, one or more transmitters 830 and/or one or more receivers 835 may be implemented and/or integrated into a multi-chip module. In some embodiments, other components such as the network interface 840 or other hardware components/circuits may be integrated with any number of transmitters 830 and/or receivers 835 into a single chip. In such embodiment, the transmitters 830 and receivers 835 may be logically configured as a transceiver 825 that uses one more common control signals or as modular transmitters 830 and receivers 835 implemented in the same hardware chip or in a multi-chip module.

[0185] Figure 9 depicts a network apparatus 900 that may be used for resource-specific CSI reporting, according to embodiments of the disclosure. In one embodiment, network apparatus 900 may be one implementation of a RAN entity, such as the base unit 121 and/or the gNB, as described above. Furthermore, the base network apparatus 900 may include a processor 905, a memory 910, an input device 915, an output device 920, and atransceiver 925. [0186] In some embodiments, the input device 915 and the output device 920 are combined into a single device, such as a touchscreen. In certain embodiments, the network apparatus 900 may not include any input device 915 and/or output device 920. In various embodiments, the network apparatus 900 may include one or more of: the processor 905, the memory 910, and the transceiver 925, and may not include the input device 915 and/or the output device 920.

[0187] As depicted, the transceiver 925 includes at least one transmitter 930 and at least one receiver 935. Here, the transceiver 925 communicates with one or more remote units 105. Additionally, the transceiver 925 may support at least one network interface 940 and/or application interface 945. The application interface(s) 945 may support one or more APIs. The network interface(s) 940 may support 3GPP reference points, such as Uu, Nl, N2 and N3. Other network interfaces 940 may be supported, as understood by one of ordinary skill in the art.

[0188] The processor 905, in one embodiment, may include any known controller capable of executing computer-readable instructions and/or capable of performing logical operations. For example, the processor 905 may be a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or similar programmable controller. In some embodiments, the processor 905 executes instructions stored in the memory 910 to perform the methods and routines described herein. The processor 905 is communicatively coupled to the memory 910, the input device 915, the output device 920, and the transceiver 925.

[0189] In various embodiments, the network apparatus 900 is a RAN node (e.g., gNB) that communicates with one or more UEs, as described herein. In such embodiments, the processor 905 controls the network apparatus 900 to perform the above described RAN behaviors. When operating as a RAN node, the processor 905 may include an application processor (also known as “main processor”) which manages application-domain and operating system (“OS”) functions and a baseband processor (also known as “baseband radio processor”) which manages radio functions.

[0190] The memory 910, in one embodiment, is a computer readable storage medium. In some embodiments, the memory 910 includes volatile computer storage media. For example, the memory 910 may include a RAM, including dynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and/or static RAM (“SRAM”). In some embodiments, the memory 910 includes non-volatile computer storage media. For example, the memory 910 may include a hard disk drive, a flash memory, or any other suitable non-volatile computer storage device. In some embodiments, the memory 910 includes both volatile and non-volatile computer storage media.

[0191] In some embodiments, the memory 910 stores data related to resource-specific CSI reporting and/or mobile operation. For example, the memory 910 may store parameters, configurations, resource assignments, policies, and the like, as described above. In certain embodiments, the memory 910 also stores program code and related data, such as an operating system or other controller algorithms operating on the apparatus 900.

[0192] The input device 915, in one embodiment, may include any known computer input device including a touch panel, a button, a keyboard, a stylus, a microphone, or the like. In some embodiments, the input device 915 may be integrated with the output device 920, for example, as a touchscreen or similar touch-sensitive display. In some embodiments, the input device 915 includes a touchscreen such that text may be input using a virtual keyboard displayed on the touchscreen and/or by handwriting on the touchscreen. In some embodiments, the input device 915 includes two or more different devices, such as a keyboard and a touch panel .

[0193] The output device 920, in one embodiment, is designed to output visual, audible, and/or haptic signals. In some embodiments, the output device 920 includes an electronically controllable display or display device capable of outputting visual data to a user. For example, the output device 920 may include, but is not limited to, an LCD display, an LED display, an OLED display, a projector, or similar display device capable of outputting images, text, or the like to a user. As another, non-limiting, example, the output device 920 may include a wearable display separate from, but communicatively coupled to, the rest of the network apparatus 900, such as a smart watch, smart glasses, a heads-up display, or the like. Further, the output device 920 may be a component of a smart phone, a personal digital assistant, a television, a table computer, a notebook (laptop) computer, a personal computer, a vehicle dashboard, or the like.

[0194] In certain embodiments, the output device 920 includes one or more speakers for producing sound. For example, the output device 920 may produce an audible alert or notification (e.g., a beep or chime). In some embodiments, the output device 920 includes one or more haptic devices for producing vibrations, motion, or other haptic feedback. In some embodiments, all or portions of the output device 920 may be integrated with the input device 915. For example, the input device 915 and output device 920 may form a touchscreen or similar touch-sensitive display. In other embodiments, the output device 920 may be located near the input device 915.

[0195] The transceiver 925 includes at least transmitter 930 and at least one receiver 935. One or more transmitters 930 may be used to communicate with the UE, as described herein. Similarly, one or more receivers 935 may be used to communicate with network functions in the PLMN and/or RAN, as described herein. Although only one transmitter 930 and one receiver 935 are illustrated, the network apparatus 900 may have any suitable number of transmitters 930 and receivers 935. Further, the transmitter(s) 930 and the receiver(s) 935 may be any suitable type of transmitters and receivers. [0196] Figure 10 depicts one embodiment of a method 1000 for resource-specific CSI reporting, according to embodiments of the disclosure. In various embodiments, the method 1000 is performed by a Tx UE device, such as the remote unit 105, and/or the user equipment apparatus 800, as described above. In some embodiments, the method 1000 is performed by a processor, such as a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

[0197] The method 1000 begins and transmits 1005 a CSI-RS within a sidelink data region (e.g., PSSCH). The method 1000 includes transmitting 1010 a CSI request indicator in SCI, the CSI request associated with a first resource pool. The method 1000 includes transmitting 1015 an aperiodic CSI trigger corresponding to a second resource pool separate from the first resource pool. The method 1000 includes receiving 1020 a first CSI report (e.g., using a MAC CE) in response to the CSI request, where the aperiodic CSI trigger corresponding to the second resource pool is sent prior to receipt of the first CSI report. The method 1000 includes receiving 1025 an aperiodic CSI report (e.g., using a MAC CE) in response to the aperiodic CSI trigger. The method 1000 ends.

[0198] Figure 11 depicts one embodiment of a method 1100 for resource-specific CSI reporting, according to embodiments of the disclosure. In various embodiments, the method 1100 is performed by a Rx UE device, such as the remote unit 105, and/or the user equipment apparatus 800, as described above. In some embodiments, the method 1100 is performed by a processor, such as a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

[0199] The method 1100 begins and receives 1105 a CSI-RS within a sidelink data region (e.g., PSSCH) . The method 1100 includes receiving 1110 a CSI request indicator in SCI, the CSI request associated with a first resource pool. The method 1100 includes receiving 1115 an aperiodic CSI trigger corresponding to a second resource pool. The method 1100 includes transmitting 1120 a first CSI report (e.g., using a MAC CE) in response to the CSI request, where the aperiodic CSI trigger corresponding to the second resource pool is sent prior to receipt of the first CSI report. The method 1100 includes transmitting 1125 an aperiodic CSI report in response to the aperiodic CSI trigger, where a CSI report window of the first CSI report overlaps with a CSI report window of the aperiodic CSI report. The method 1100 ends.

[0200] Disclosed herein is a first apparatus for resource-specific CSI reporting, according to embodiments of the disclosure. The first apparatus may be implemented by a Tx UE device, such as the remote unit 105, the Tx UE 205, and/or the user equipment apparatus 800, described above. The first apparatus includes a transceiver for communicating on a sidelink interface and a processor that transmits a CSI-RS within a sidelink data region (e.g., PSSCH) and transmits a CSI request indicator in SCI, where the CSI request is associated with a first resource pool. Additionally, the processor transmits an aperiodic CSI trigger corresponding to a second resource pool separate from the first resource pool. Via the transceiver, the processor receives a first CSI report (e.g., using a MAC CE) in response to the CSI request and receives an aperiodic CSI report (e.g., using a MAC CE) in response to the aperiodic CSI trigger, where the aperiodic CSI trigger corresponding to the second resource pool is sent prior to receipt of the first CSI report.

[0201] In some embodiments, the processor indicates an association of a resource pool to a transmitted aperiodic CSI trigger and corresponding CSI report. In certain embodiments, each CSI report (e.g., MAC CE) indicates a resource pool identifier for which CSI measurements were performed. In certain embodiments, the SCI indicates a resource pool identifier of the first resource pool to be used for the transmission of CSI report.

[0202] In certain embodiments, the SCI and the aperiodic CSI report (e.g., MAC CE) indicate one of: a trigger index and a sequence number. In certain embodiments, the aperiodic CSI report (e.g., MAC CE) includes one of: a slot index of the corresponding CSI trigger and slot offset of the corresponding CSI trigger. In some embodiments, the processor maintains a separate report timer (e.g., si CSI-ReportTime ) for each resource pool.

[0203] In some embodiments, transmitting the CSI-RS includes transmitting a plurality of CSI-RSs over a plurality of CSI-RS occasions, where the aperiodic CSI report contains an averaged value (e.g., CGI/RI value) that is calculated over multiple CSI-RS occasions. In certain embodiments, the aperiodic CSI trigger is transmitted together with the last CSI-RS. In other embodiments, the aperiodic CSI trigger is transmitted is a separate SCI after with the last CSI-RS.

[0204] In some embodiments, the processor configures a plurality of CSI report latency requirements (e.g., sl-LatencyBound-CSI-Report), each latency requirement being associated with a particular resource pool. In some embodiments, the processor configures a plurality of CSI report latency requirements (e.g., sl-LatencyBound-CSI-Report), each latency requirement being associated with a particular priority value in SCI.

[0205] In some embodiments, the first and second resource pools include non-overlapping sub-channels. In some embodiments, the first resource pool is associated with a first priority and the second resource pool is associated with a second priority. In certain embodiments, the CSI trigger is sent prior to receipt of the first CSI report in response to the second priority being higher than the first priority. In some embodiments, a CSI report window of the first CSI report overlaps with a CSI report window of the aperiodic CSI report. [0206] In some embodiments, the apparatus is allocated semi-persistent sidelink resources (e.g., SL CG) having a configured grant periodicity, where transmitting the CSI-RS includes transmitting within a semi-persistent sidelink resource (e.g., CG resource). In certain embodiments, the semi-persistent sidelink resource used for CSI-RS transmission is a separate configured grant resource. In certain embodiments, the first CSI report is received at the end of a configured grant period.

[0207] Disclosed herein is a first method for resource-specific CSI reporting, according to embodiments of the disclosure. The first method may be performed by a Tx UE device, such as the remote unit 105, the Tx UE 205, and/or the user equipment apparatus 800, described above. The first method includes transmitting a CSI-RS within a sidelink data region (e.g., PSSCH) and transmitting a CSI request indicator in SCI, the CSI request associated with a first resource pool. The first method includes transmitting an aperiodic CSI trigger corresponding to a second resource pool separate from the first resource pool and receiving a first CSI report (e.g., using a MAC CE) in response to the CSI request, where the aperiodic CSI trigger corresponding to the second resource pool is sent prior to receipt of the first CSI report. The first method includes receiving an aperiodic CSI report (e.g., using a MAC CE) in response to the aperiodic CSI trigger.

[0208] In some embodiments, the first method includes signaling an association of a resource pool to a transmitted aperiodic CSI trigger and corresponding CSI report. In certain embodiments, each CSI report (e.g., MAC CE) indicates a resource pool identifier for which CSI measurements were performed. In certain embodiments, the SCI indicates a resource pool identifier of the first resource pool to be used for the transmission of CSI report.

[0209] In certain embodiments, the SCI and the aperiodic CSI report (e.g., MAC CE) indicate one of: a trigger index and a sequence number. In certain embodiments, the aperiodic CSI report (e.g., MAC CE) includes one of: a slot index of the corresponding CSI trigger and slot offset of the corresponding CSI trigger. In some embodiments, the first method includes maintaining a separate report timer (e.g., si CSI-ReportTimer) for each resource pool.

[0210] In some embodiments, transmitting the CSI-RS includes transmitting a plurality of CSI-RSs over a plurality of CSI-RS occasions, where the aperiodic CSI report contains an averaged value (e.g., CGI/RI value) that is calculated over multiple CSI-RS occasions. In certain embodiments, the aperiodic CSI trigger is transmitted together with the last CSI-RS. In other embodiments, the aperiodic CSI trigger is transmitted is a separate SCI after with the last CSI-RS.

[0211] In some embodiments, the first method includes configuring a plurality of CSI report latency requirements (e.g., sl-LatencyBound-CSI-Report), each latency requirement being associated with a particular resource pool. In some embodiments, the first method includes configuring a plurality of CSI report latency requirements (e.g., sl-LatencyBound-CSI-Report), each latency requirement being associated with a particular priority value in SCI.

[0212] In some embodiments, the first and second resource pools include non-overlapping sub-channels. In some embodiments, the first resource pool is associated with a first priority and the second resource pool is associated with a second priority. In certain embodiments, the CSI trigger is sent prior to receipt of the first CSI report in response to the second priority being higher than the first priority. In some embodiments, a CSI report window of the first CSI report overlaps with a CSI report window of the aperiodic CSI report.

[0213] In some embodiments, the Tx UE is allocated semi -persistent sidelink resources (e.g., allocated a SL CG) having a configured grant periodicity, where transmitting the CSI-RS includes transmitting within a semi-persistent sidelink resource (e.g., CG resource). In certain embodiments, the semi-persistent sidelink resource used for CSI-RS transmission is a separate configured grant resource. In certain embodiments, the first CSI report is received at the end of a configured grant period.

[0214] Disclosed herein is a second apparatus for resource-specific CSI reporting, according to embodiments of the disclosure. The second apparatus may be implemented by a Rx UE device, such as the remote unit 105, the Rx UE 210, and/or the user equipment apparatus 800, described above. The second apparatus includes a transceiver for communicating on a sidelink interface and a processor that receives a CSI-RS within a sidelink data region (e.g., PSSCH) and receives a CSI request indicator in SCI, the CSI request associated with a first resource pool. The processor receives receiving an aperiodic CSI trigger corresponding to a second resource pool and transmitting a first CSI report (e.g., using a MAC CE) in response to the CSI request, where the aperiodic CSI trigger corresponding to the second resource pool is received prior to sending the first CSI report. Via the transceiver, the processor transmits an aperiodic CSI report (e.g., using a MAC CE) in response to the aperiodic CSI trigger, where a CSI report window of the first CSI report overlaps with a CSI report window of the aperiodic CSI report.

[0215] In some embodiments, the processor performs an LCP procedure to prioritize transmission of a plurality of CSI reports when there are multiple CSI triggers concurrently pending for separate resource pools. In certain embodiments, each resource pool has a priority level, where the LCP procedure operates on the priority levels of the separate resource pools. In certain embodiments, each resource pool is associated with a specific latency requirement (i.e., latency bound), where the LCP procedure operates on the latency requirements of the separate resource pools. [0216] In some embodiments, the transceiver receives an indication of an association of a resource pool to a transmitted aperiodic CSI trigger and corresponding CSI report. In certain embodiments, each CSI report (e.g., MAC CE) indicates a resource pool identifier for which CSI measurements were performed. In certain embodiments, the SCI indicates a resource pool identifier of the first resource pool to be used for the transmission of CSI report.

[0217] In certain embodiments, the SCI and the aperiodic CSI report (e.g., MAC CE) indicate one of: a trigger index and a sequence number. In certain embodiments, the aperiodic CSI report (e.g., MAC CE) includes one of: a slot index of the corresponding CSI trigger and slot offset of the corresponding CSI trigger.

[0218] In some embodiments, receiving the CSI-RS includes receiving a plurality of CSI- RSs over a plurality of CSI-RS occasions, where the aperiodic CSI report contains an averaged value (e.g., CGI/RI value) that is calculated over multiple CSI-RS occasions. In certain embodiments, the aperiodic CSI trigger is transmitted together with the last CSI-RS. In other embodiments, the aperiodic CSI trigger is transmitted is a separate SCI after with the last CSI-RS.

[0219] In some embodiments, the transceiver receives a plurality of CSI report latency requirements (e.g., sl-LatencyBound-CSI-Report), each latency requirement being associated with a particular resource pool . In some embodiments, the transceiver receives a plurality of CSI report latency requirements (e.g., sl-LatencyBound-CSI-Report), each latency requirement being associated with a particular priority value in SCI.

[0220] In some embodiments, the first and second resource pools include non-overlapping sub-channels. In some embodiments, the first resource pool is associated with a first priority and the second resource pool is associated with a second priority. In certain embodiments, the CSI trigger is sent prior to receipt of the first CSI report in response to the second priority being higher than the first priority.

[0221] In some embodiments, receiving the CSI-RS includes receiving within a semi- persistent sidelink resource (e.g., CG resource). In certain embodiments, the first CSI report is transmitted at the end of a configured grant period.

[0222] Disclosed herein is a second method for resource-specific CSI reporting, according to embodiments of the disclosure. The second method may be performed by a Rx UE device, such as the remote unit 105, the Rx UE 210, and/or the user equipment apparatus 800, described above. The second method includes receiving a CSI-RS within a sidelink data region (e.g., PSSCH) and receiving a CSI request indicator in SCI, the CSI request associated with a first resource pool. The second method includes receiving an aperiodic CSI trigger corresponding to a second resource pool and transmitting a first CSI report (e.g., using a MAC CE) in response to the CSI request, where the aperiodic CSI trigger corresponding to the second resource pool is sent prior to receipt of the first CSI report. The second method includes transmitting an aperiodic CSI report in response to the aperiodic CSI trigger, where a CSI report window of the first CSI report overlaps with a CSI report window of the aperiodic CSI report.

[0223] In some embodiments, the second method includes performing an LCP procedure to prioritize transmission of a plurality of CSI reports when multiple CSI triggers are concurrently pending for separate resource pools. In certain embodiments, each resource pool has a priority level, where the LCP procedure operates on the priority levels of the separate resource pools. In certain embodiments, each resource pool is associated with a specific latency requirement (i.e., latency bound), where the LCP procedure operates on the latency requirements of the separate resource pools.

[0224] In some embodiments, the second method includes receiving an indication of an association of a resource pool to a transmitted aperiodic CSI trigger and corresponding CSI report. In certain embodiments, each CSI report (e.g., MAC CE) indicates a resource pool identifier for which CSI measurements were performed. In certain embodiments, the SCI indicates a resource pool identifier of the first resource pool to be used for the transmission of CSI report.

[0225] In certain embodiments, the SCI and the aperiodic CSI report (e.g., MAC CE) indicate one of: a trigger index and a sequence number. In certain embodiments, the aperiodic CSI report (e.g., MAC CE) includes one of: a slot index of the corresponding CSI trigger and slot offset of the corresponding CSI trigger.

[0226] In some embodiments, receiving the CSI-RS includes receiving a plurality of CSI- RSs over a plurality of CSI-RS occasions, where the aperiodic CSI report contains an averaged value (e.g., CGI/RI value) that is calculated over multiple CSI-RS occasions. In certain embodiments, the aperiodic CSI trigger is transmitted together with the last CSI-RS. In other embodiments, the aperiodic CSI trigger is transmitted is a separate SCI after with the last CSI-RS.

[0227] In some embodiments, the second method includes receiving a plurality of CSI report latency requirements (e.g., sl-LatencyBound-CSI-Report), each latency requirement being associated with a particular resource pool. In some embodiments, the second method includes receiving a plurality of CSI report latency requirements (e.g., sl-LatencyBound-CSI-Report), each latency requirement being associated with a particular priority value in SCI.

[0228] In some embodiments, the first and second resource pools include non-overlapping sub-channels. In some embodiments, the first resource pool is associated with a first priority and the second resource pool is associated with a second priority. In certain embodiments, the CSI trigger is sent prior to receipt of the first CSI report in response to the second priority being higher than the first priority.

[0229] In some embodiments, receiving the CSI-RS includes receiving within a semi- persistent sidelink resource (e.g., CG resource). In certain embodiments, the first CSI report is transmitted at the end of a configured grant period.

[0230] Embodiments may be practiced in other specific forms. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.