Apparatus and method for reference anchor UE for sidelink positioning

Abstract

Aspects of the present disclosure relate to a reference anchor UE for sidelink positioning of a target UE. The reference anchor may be selected by the target UE or a positioning entity, such as a location management function (LMF) or a server UE. A target UE may receive an initial list of anchor UEs, select a set of active anchor UEs from the initial list of anchor UEs, select a reference anchor UE from the set of active anchor UEs using one or more selection criteria, perform one or more sidelink positioning measurements with respect to the reference anchor UE, and perform one or more sidelink positioning measurements with respect to the reference anchor UE. And transmitting the one or more sidelink positioning measurements and information of the reference anchor UE to a location computing entity.

Description

Technical Field

[0001] This disclosure relates to wireless communication, and more specifically to sidelink positioning of a UE using a reference anchor. Background Technology

[0002] A wireless communication system may include one or more network communication devices, such as base stations, which may also be referred to as eNodeB (eNB), next-generation NodeB (gNB), or other suitable terms. Each network communication device, such as a base station, may support wireless communication with one or more user communication devices, which may also be referred to as user equipment (UE), or other suitable terms. The wireless communication system may support wireless communication with one or more user communication devices by utilizing the resources of the wireless communication system (e.g., time resources (e.g., symbols, time slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers). In addition, the wireless communication system may support wireless communication across various radio access technologies, including third-generation (3G) radio access technology, fourth-generation (4G) radio access technology, fifth-generation (5G) radio access technology, and other suitable radio access technologies beyond 5G (e.g., sixth-generation (6G)).

[0003] Approval was granted for the introduction of a sidelink (SL) positioning framework to support diverse target positioning requirements across various use cases. SL positioning is intended for application in a wide range of use cases, such as vehicle-to-everything (V2X), public safety, industrial IoT (IIoT), and commercial use cases. The purpose of SL positioning is to determine the absolute or relative position of a UE, or the distance or direction between a pair of UEs, using various SL positioning methods, such as SL round-trip time (RTT) methods, including one-sided and two-sided RTT, SL angle of arrival (AoA), SL-TOA (SL time of arrival), and SL time difference of arrival (TDOA). SL positioning is implemented using a sidelink positioning reference signal (SL-PRS) transmitted via the PC5 (SL) interface and will be supported in multiple coverage scenarios (within coverage, partial coverage, and out of coverage). SL positioning is also supported for network-based, network-assisted, and UE-only operational positioning scenarios. The sidelink positioning protocol (SLPP) is also designed to support the transmission of all relevant SL positioning messages between the LMF and the UE, and between a pair of UEs.

[0004] TDoA is a mature positioning technology used to provide the absolute location of one or more UEs and is one of the key supported positioning technologies in sidelinks; it is also known as SL-TDoA. For good positioning performance, SL-TDoA requires at least three anchor nodes, tight synchronization between the anchor nodes (ideally with no synchronization errors), and a diverse geometric layout of the anchor nodes. In practice, it is difficult to guarantee these conditions using known technologies. Summary of the Invention

[0005] This disclosure relates to methods, apparatus, and systems for supporting the identification, selection, and configuration of a reference anchor UE to support an optimized SL-TDoA process. Embodiments of this disclosure provide more accurate and efficient sidelink positioning of the target UE.

[0006] Some embodiments of the methods and apparatus described herein may further include a user equipment (UE) for wireless communication, comprising: at least one memory; and at least one processor coupled to the at least one memory and configured to cause the UE to: select a reference anchor UE from a set of active anchor UEs using one or more selection criteria; perform sidelink measurements for positioning relative to the selected reference anchor UE; and transmit one or more of the following: a sidelink measurement report at least in part based on the performed sidelink measurements or information associated with the reference anchor UE.

[0007] In some embodiments of the methods and apparatus described herein, the at least one processor is further configured to cause the UE to: receive a list of anchor UEs; and select a set of active anchor UEs from the list of anchor UEs, wherein the list of anchor UEs is received from a server UE or a location management function (LMF), and wherein one or more of the sidelink measurement reports or information associated with the reference anchor UE are transmitted to the server UE or the LMF.

[0008] In some implementations of the methods and apparatus described herein, the anchor UE list is received in a message that serves as a container for carrying side-link positioning protocol (SLPP) messages, or the anchor UE list is received in the SLPP message.

[0009] In some embodiments of the methods and apparatus described herein, the selection criteria include at least one of the following: a threshold for a lateral link reference signal; a line-of-sight (LoS) state associated with the UE or one or more of each of at least one of the group of active anchor UEs; a coverage state associated with the UE or one or more of each of at least one of the group of active anchor UEs; whether a lateral link time difference of arrival (SL-TDoA) measurement is supported by the UE or one or more of each of at least one of the group of active anchor UEs; whether the location of each of at least one of the group of active anchor UEs is available in a multidimensional space; and public terrestrial mobile network (PLMN) information associated with each of the group of active anchor UEs.

[0010] In some embodiments of the methods and apparatus described herein, the at least one processor is further configured to cause the UE to: sort each active anchor UE in the active anchor UE list; and transmit an indication of the sorted active anchor UEs.

[0011] In some implementations of the methods and apparatus described herein, the information associated with the reference anchor UE includes an identifier of the reference anchor UE.

[0012] In some implementations of the methods and apparatus described herein, the information associated with the reference anchor UE includes one or more of the following: one or more sidelink reference signal time difference (SL-RSTD) measurements; application layer identifier; temporary mobile subscriber identity (TMSI); source identifier; destination identifier; anchor UE identifier; and temporary reference anchor UE identifier.

[0013] In some implementations of the methods and apparatus described herein, the selected reference anchor UE is a first reference anchor UE, and the at least one processor is further configured such that the UE: at least in part selects a second reference anchor UE for a Side Link Positioning Protocol (SLPP) session as the first reference anchor UE based on one or more selection criteria.

[0014] In some embodiments of the methods and apparatus described herein, the at least one processor is further configured to cause the UE to: perform one or more side link reference signal time difference (SL-RSTD) measurements using the first reference anchor UE and the second reference anchor UE; and transmit a report of the SL-RSTD measurements using the first reference UE and the second reference UE, wherein the transmitted report associates each SL-RSTD measurement with one or more of the first reference anchor UE or the second reference anchor UE.

[0015] Some embodiments of the methods and apparatus described herein may further include a processor for wireless communication, comprising: at least one memory; and a controller coupled to the at least one memory and configured to: select a reference anchor UE from a set of active anchor UEs using one or more selection criteria; perform sidelink measurements for positioning relative to the selected reference anchor UE; and transmit one or more of the following: a sidelink measurement report at least in part based on the performed sidelink measurements or information associated with the reference anchor UE.

[0016] Some embodiments of the methods and apparatus described herein may further include an apparatus for performing network functions, the apparatus comprising: at least one memory; and at least one processor coupled to the at least one memory and configured to enable the apparatus to: transmit an initial anchor UE list to a target UE; receive a set of active anchor UEs from the initial anchor UE list from the target UE; select a reference anchor UE from the set of active anchor UEs using one or more selection criteria; receive side-link location measurements from the target UE; and calculate the location of the target UE using the side-link location measurements.

[0017] In some implementations of the methods and devices described herein, the device receives a list of candidate UEs from the target UE and generates the initial anchor UE list from the list of candidate UEs.

[0018] In some implementations of the methods and devices described herein, the initial list of anchor UEs is transmitted in a Side Link Positioning Protocol (SLPP) message.

[0019] In some implementations of the methods and apparatus described herein, the selection criteria are pre-configured in the apparatus.

[0020] In some embodiments of the methods and apparatus described herein, the selection criteria include at least one of the following: a threshold of the lateral link reference signal received by the target UE; the line-of-sight status between the target UE and the corresponding anchor UE; coverage status; support for lateral link time difference of arrival (SL-TDoA) measurement; whether the location of the corresponding anchor UE is available in a two-dimensional or three-dimensional location; and the public land mobile network (PLMN) information of the corresponding anchor UE.

[0021] In some embodiments of the methods and apparatus described herein, the at least one processor is further configured to enable the apparatus to transmit auxiliary information to the selected reference anchor UE.

[0022] In some implementations of the methods and apparatus described herein, the auxiliary information includes at least one of the following: a sidelink positioning reference signal (SL-PRS) resource ID, comb size, SL-PRS periodicity, comb size offset, number of symbols, and dedicated SL-PRS or shared resource pool information, or relevant configurations required to transmit SL-PRS to another UE (e.g., a target UE).

[0023] In some embodiments of the methods and apparatus described herein, the location of the target UE is calculated based on a set of SL-RSTD measurements, each of which is based on a first time-of-arrival measurement between the target UE and the reference anchor UE and a second time-of-arrival measurement between the target UE and an anchor UE from the set of active anchor UEs. Attached Figure Description

[0025] Figure 1 This describes an example of a wireless communication system that uses a reference anchor UE for side-link positioning in support of aspects of this disclosure.

[0026] Figure 2 This describes an example of a processor that supports side-link localization using a reference anchor UE in accordance with aspects of this disclosure.

[0027] Figure 3 Illustrate an example of beam-based positioning in an NR network.

[0028] Figure 4 Illustrate examples of absolute and relative positioning in wireless cellular networks.

[0029] Figure 5 This section describes an example of configuring SL PRS resources in SL BWP.

[0030] Figure 6 An example illustrating the message flow of the sidelink mobile terminal location request (SL-MT-LR) process.

[0031] Figure 7 An example illustrating the message flow of the sidelink mobile originating location request (SL-MO-LR) process.

[0032] Figure 8 This describes an example of an apparatus for side-link positioning using a reference anchor UE, supported by aspects of this disclosure.

[0033] Figure 9 This document describes an example of signaling and processing operations performed using a reference anchor UE for sidelink positioning, in accordance with aspects of this disclosure.

[0034] Figure 10A and Figure 10B This document describes examples of measurements using different reference anchor UEs for side-link localization supported by aspects of this disclosure.

[0035] Figure 11 and 12 A flowchart illustrating a method for side-link localization using a reference anchor UE in support of aspects of this disclosure. Detailed Implementation

[0036] A key unresolved issue in lateral link localization (LLT) involves the derivation of the SL reference signal time difference (SL-RSTD) measurement for SL-TDoA. The LLT-RSTD is derived based on the time of arrival (TOA) difference between a LLT-PRS transmission originating from one anchor device and another SL-PRS transmission originating from another anchor device. Given the number of anchor UEs involved and the different combinations from which SL-RSTD measurements are derived, this SL-RSTD measurement derived from a pair of SL-PRS receivers can be difficult to track and manage. In some scenarios, the number of SL-RTSD measurements may be high, and the quality of some SL-RTSD measurements may be low, leading to inefficient and inaccurate location calculations. These problems can be addressed by establishing a reference anchor UE from which a configured set of SL-RSTD measurements is derived, and which measurements from the reference anchor UE are preferentially used when calculating the location of the target UE.

[0037] In the context of SL positioning, various SL positioning techniques can be used to achieve good SL positioning performance. This disclosure addresses the problem of managing one or more sidelink reference anchor UEs, which is important for SL-TDoA positioning because SL-RSTD measurements are derived from a pair of received SL-PRS transmissions using Time of Arrival (“TOA”) measurements originating from a pair of anchor UEs. Therefore, it is helpful to distinguish which of the anchor UEs is the active reference anchor UE in order to correlate the set of sidelink reference signal time difference (SL-RSTD) measurements performed by the UE.

[0038] One aspect of this disclosure describes a method and apparatus for supporting a reference anchor UE procedure in network-based positioning, including a location server involved in performing location management functions (LMF). Another aspect of this disclosure describes a method and apparatus for supporting a reference anchor UE procedure in a UE-only positioning scenario that does not directly involve LMF. Reference anchor UE selection criteria and reference anchor UE prioritization are described for both network-based and UE-only positioning scenarios. Furthermore, a method and apparatus for providing dedicated SL-PRS configuration information to the reference anchor UE are described, along with additional methods for distinguishing the reference anchor UE in both network-based and UE-only positioning scenarios.

[0039] Therefore, this disclosure proposes systems, apparatus, and methods for identifying, selecting, and configuring reference anchor UEs to support an optimized SL-TDoA process. In one embodiment, a process provides identification and selection of a reference UE for network-based positioning scenarios involving a location server associated with an LMF. In another embodiment, a process provides identification and selection of a reference UE for UE-only positioning scenarios that do not involve a location server, which is particularly relevant in out-of-coverage scenarios.

[0040] The embodiments of this disclosure provide more accurate and efficient processing for side-link time difference measurement and positioning of the target UE.

[0041] The aspects of this disclosure are described in the context of a wireless communication system. Reference is made to apparatus diagrams and flowcharts for further illustration and description of these aspects.

[0042] Figure 1 This description illustrates an example of a wireless communication system 100 that supports sidelink positioning using a reference anchor UE according to aspects of this disclosure. The wireless communication system 100 may include one or more network entities 102, one or more UEs 104, a core network 106, and a packet data network 108. The wireless communication system 100 may support various radio access technologies. In some embodiments, the wireless communication system 100 may be a 4G network, such as an LTE network or an LTE-A (LTE-Advanced) network. In some other embodiments, the wireless communication system 100 may be a 5G network, such as an NR network. In other embodiments, the wireless communication system 100 may be a combination of 4G and 5G networks, or other suitable radio access technologies, including IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), and IEEE 802.20. The wireless communication system 100 may support radio access technologies beyond 5G. In addition, the wireless communication system 100 can support technologies such as Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), or Code Division Multiple Access (CDMA).

[0043] One or more network entities 102 may be distributed throughout a geographic area to form a wireless communication system 100. One or more of the network entities 102 described herein may be, include, or be referred to as a network node, base station, network element, radio access network (RAN), base transceiver station, access point, NodeB, eNodeB (eNB), next-generation NodeB (gNB), or other suitable terms. Network entities 102 and UE 104 may communicate via communication link 110, which may be a wireless or wired connection. For example, network entities 102 and UE 104 may perform wireless communication (e.g., receive signaling, transmit signaling) via a Uu interface.

[0044] Network entity 102 can provide a geographic coverage area 112, for which network entity 102 can support services (e.g., voice, video, packet data, messaging, broadcasting, etc.) for one or more UEs 104 within the geographic coverage area 112. For example, network entity 102 and UE 104 can support wireless communication of signals associated with services (e.g., voice, video, packet data, messaging, broadcasting, etc.) according to one or more radio access technologies. In some embodiments, network entity 102 can be mobile, for example, a satellite associated with a non-terrestrial network. In some embodiments, different geographic coverage areas 112 associated with the same or different radio access technologies can overlap, but different geographic coverage areas 112 can be associated with different network entities 102. The information and signals described herein can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips referenced throughout this description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or optical particles, or any combination thereof.

[0045] One or more UEs 104 may be distributed throughout the geographic area of ​​the wireless communication system 100. UE 104 may include or be referred to as a mobile device, wireless device, remote device, remote unit, handheld device, or subscriber device, or some other suitable term. In some embodiments, UE 104 may be referred to as a unit, station, terminal, or client, and other instances. Alternatively, UE 104 may be referred to as an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a Machine-Type Communication (MTC) device, and other instances. In some embodiments, UE 104 may be stationary within the wireless communication system 100. In some other embodiments, UE 104 may be mobile within the wireless communication system 100.

[0046] One or more UEs 104 may be devices in different forms or with different capabilities. Figure 1 This section describes some examples of UE 104. UE 104 can communicate with various types of devices, such as network entity 102, other UEs 104, or network equipment (e.g., core network 106, packet data network 108, relay device, integrated access and backhaul (IAB) node, or another network device), such as... Figure 1 As shown in the diagram. Alternatively, UE 104 may support communication with other network entities 102 or UE 104, which may act as repeaters in the wireless communication system 100.

[0047] UE 104 may also support direct wireless communication with other UE 104s via communication link 114. For example, UE 104 may support direct wireless communication with another UE 104 via a device-to-device (D2D) communication link. In some implementations (e.g., vehicle-to-vehicle (V2V) deployment, vehicle-to-everything (V2X) deployment, or cellular V2X deployment), communication link 114 may be referred to as a sidelink. For example, UE 104 may support direct wireless communication with another UE 104 via a PC5 interface.

[0048] Network entity 102 may support communication with core network 106 or another network entity 102, or both. For example, network entity 102 may interface with core network 106 via one or more backhaul links 116 (e.g., via S1, N2, or another network interface). Network entities 102 may communicate with each other via backhaul links 116 (e.g., via X2, Xn, or another network interface). In some embodiments, network entities 102 may communicate directly with each other (e.g., between network entities 102). In some other embodiments, network entities 102 may communicate with each other or indirectly (e.g., via core network 106). In some embodiments, one or more network entities 102 may include sub-components, such as access network entities, which may be instances of access node controllers (ANCs). The ANC may communicate with one or more UEs 104 via one or more other access network transport entities, which may be referred to as wireless heads, smart wireless heads, or transmit-receive points (TRPs).

[0049] In some implementations, network entity 102 may be configured in a decomposed architecture that can utilize protocol stacks physically or logically distributed across two or more network entities 102, such as an integrated access backhaul (IAB) network, an open RAN (O-RAN) (e.g., a network configuration initiated by the O-RAN Alliance), or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN)). For example, network entity 102 may include one or more of a central unit (CU), a distributed unit (DU), a radio unit (RU), a RAN intelligent controller (RIC) (e.g., a near real-time RIC, a non-real-time RIC), a service management and orchestration (SMO) system, or any combination thereof.

[0050] The RU may also be referred to as a radio head, intelligent radio head, remote radio head (RRH), remote radio unit (RRU), or transmit-receive point (TRP). One or more components of network entity 102 in the decomposed RAN architecture may be co-located, or one or more components of network entity 102 may be located in distributed locations (e.g., separate physical locations). In some embodiments, one or more network entities 102 in the decomposed RAN architecture may be implemented as virtual units (e.g., virtual CU (VCU), virtual DU (VDU), virtual RU (VRU)).

[0051] The functional decomposition between CU, DU, and RU can be flexible and can support different functionalities depending on which functions (e.g., network layer functions, protocol layer functions, baseband functions, radio frequency functions, and any combination thereof) are performed at the CU, DU, or RU. For example, protocol stack functional decomposition can be used between the CU and DU, such that the CU can support one or more layers of the protocol stack and the DU can support one or more different layers of the protocol stack. In some implementations, the CU can host upper protocol layer (e.g., Layer 3 (L3), Layer 2 (L2)) functionalities and signaling (e.g., Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), Packet Data Convergence Protocol (PDCP)). The CU can connect to one or more DUs or RUs, and one or more DUs or RUs can host lower protocol layer functionalities, such as Layer 1 (L1) (e.g., Physical (PHY) layer) or L2 (e.g., Radio Link Control (RLC) layer, Media Access Control (MAC) layer) functionalities and signaling, and each can be at least partially controlled by the CU 160.

[0052] Alternatively, a functional split of the protocol stack can be employed between the DU and RU, allowing the DU to support one or more layers of the protocol stack and the RU to support one or more different layers of the protocol stack. The DU can support one or more different cells (e.g., via one or more RUs). In some implementations, the functional split between the CU and DU, or between the DU and RU, can be within the protocol layer (e.g., some functions of the protocol layer can be performed by one of the CU, DU, or RU, while other functions of the protocol layer are performed by different of the CU, DU, or RU).

[0053] The CU can be further functionally decomposed into CU control plane (CU-CP) and CU user plane (CU-UP) functions. The CU can be connected to one or more DUs via midhaul communication links (e.g., F1, F1-c, F1-u), and the DUs can be connected to one or more RUs via fronthaul communication links (e.g., open fronthaul (FH) interfaces). In some embodiments, the midhaul or fronthaul communication links can be implemented according to the interfaces (e.g., channels) between layers of a protocol stack supported by corresponding network entities 102 communicating via such communication links.

[0054] Core network 106 can support user authentication, access authorization, tracking, connectivity, and other access, routing, or mobility functions. Core network 106 can be an evolved packet core (EPC) or a 5G core (5GC), and may include control plane entities (e.g., Mobility Management Entity (MME), Access and Mobility Management Function (AMF)) that manage access and mobility, and user plane entities (e.g., Serving Gateway (S-GW), Packet Data Network (PDN) Gateway (P-GW), or User Plane Function (UPF)) or control and user plane entities, such as a Location Management Function (LMF) responsible for providing location services. In some embodiments, the control plane entity can manage one or more non-access stratum (NAS) functions of UE 104 served by one or more network entities 102 associated with core network 106, such as mobility, authentication, and bearer management (e.g., data bearers, signaling bearers, etc.).

[0055] Core network 106 can communicate with packet data network 108 via one or more backhaul links 116 (e.g., via S1, N2, or another network interface). Packet data network 108 may include application server 118. In some embodiments, one or more UEs 104 may communicate with application server 118. UE 104 may establish a session (e.g., Protocol Data Unit (PDU) session, etc.) with core network 106 via network entity 102. Core network 106 can use the established session (e.g., established PDU session) to route services (e.g., control information, data, etc.) between UE 104 and application server 118. A PDU session may be an instance of a logical connection between UE 104 and core network 106 (e.g., one or more network functions of core network 106).

[0056] In the wireless communication system 100, network entity 102 and UE 104 can use the resources of the wireless communication system 100 (e.g., time resources (e.g., symbols, time slots, subframes, frames, or the like) or frequency resources (e.g., subcarriers, carriers)) to perform various operations (e.g., wireless communication). In some embodiments, network entity 102 and UE 104 may support different resource structures. For example, network entity 102 and UE 104 may support different frame structures. In some embodiments, such as in 4G, network entity 102 and UE 104 may support a single frame structure. In some other embodiments, such as in 5G and other suitable radio access technologies, network entity 102 and UE 104 may support various frame structures (i.e., multiple frame structures). Network entity 102 and UE 104 may support various frame structures based on one or more parameter sets.

[0057] The wireless communication system 100 may support one or more parameter sets, and the parameter sets may include subcarrier spacing and cyclic prefixes. A first parameter set (e.g., μ=0) may be associated with a first subcarrier spacing (e.g., 15 kHz) and a regular cyclic prefix. In some embodiments, the first parameter set (e.g., μ=0) associated with the first subcarrier spacing (e.g., 15 kHz) may utilize one time slot per subframe. A second parameter set (e.g., μ=1) may be associated with a second subcarrier spacing (e.g., 30 kHz) and a regular cyclic prefix. A third parameter set (e.g., μ=2) may be associated with a third subcarrier spacing (e.g., 60 kHz) and a regular cyclic prefix or an extended cyclic prefix. A fourth parameter set (e.g., μ=3) may be associated with a fourth subcarrier spacing (e.g., 120 kHz) and a regular cyclic prefix. A fifth parameter set (e.g., μ=4) may be associated with a fifth subcarrier spacing (e.g., 240 kHz) and a regular cyclic prefix.

[0058] Time intervals for resources (e.g., communication resources) can be organized according to frames (also known as radio frames). Each frame may have a certain duration, for example, 10 milliseconds (ms). In some embodiments, each frame may contain multiple subframes. For example, each frame may contain 10 subframes, and each subframe may have a certain duration, for example, 1 ms. In some embodiments, each frame may have the same duration. In some embodiments, each subframe of a frame may have the same duration.

[0059] Alternatively, the time intervals of resources (e.g., communication resources) can be organized according to time slots. For example, a subframe may contain a certain number (e.g., quantity) of time slots. The number of time slots in each subframe may also depend on one or more parameter sets supported in the wireless communication system 100. For example, the first, second, third, fourth, and fifth parameter sets (i.e., μ=0, μ=1, μ=2, μ=3, μ=4) associated with corresponding subcarrier intervals of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz may utilize a single time slot per subframe, two time slots per subframe, four time slots per subframe, eight time slots per subframe, and 16 time slots per subframe, respectively. Each time slot may contain a certain number (e.g., quantity) of symbols (e.g., OFDM symbols). In some embodiments, the number (e.g., quantity) of time slots in a subframe may depend on the parameter set. For a conventional cyclic prefix, a time slot may contain 14 symbols. For an extended cyclic prefix (e.g., applicable to a 60 kHz subcarrier spacing), a time slot may contain 12 symbols. The relationship between the number of symbols per time slot for the regular cyclic prefix and the extended cyclic prefix, the number of time slots per subframe, and the number of time slots per frame may depend on the parameter set. It should be understood that references to the first parameter set (e.g., μ=0) associated with the first subcarrier spacing (e.g., 15 kHz) may be used interchangeably between subframes and time slots.

[0060] In the wireless communication system 100, the electromagnetic (EM) spectrum can be divided into various categories, frequency bands, channels, etc., based on frequency or wavelength. For example, the wireless communication system 100 may support one or more operating frequency bands, such as frequency range names FR1 (410 MHz to 7.125 GHz), FR2 (24.25 GHz to 52.6 GHz), FR3 (7.125 GHz to 24.25 GHz), FR4 (52.6 GHz to 114.25 GHz), FR4a or FR4-1 (52.6 GHz to 71 GHz), and FR5 (114.25 GHz to 300 GHz). In some embodiments, network entity 102 and UE 104 can perform wireless communication through one or more of the operating frequency bands. In some embodiments, FR1 can be used by network entity 102 and UE 104, as well as other equipment or devices, for cellular communication services (e.g., control information, data). In some implementations, FR2 can be used by network entity 102 and UE 104, as well as other equipment or devices, for short-range, high-data-rate capabilities.

[0061] FR1 may be associated with one or more parameter sets (e.g., at least three parameter sets). For example, FR1 may be associated with a first parameter set containing a 15 kHz subcarrier spacing (e.g., μ=0); a second parameter set containing a 30 kHz subcarrier spacing (e.g., μ=1); and a third parameter set containing a 60 kHz subcarrier spacing (e.g., μ=2). FR2 may be associated with one or more parameter sets (e.g., at least two parameter sets). For example, FR2 may be associated with a third parameter set containing a 60 kHz subcarrier spacing (e.g., μ=2); and a fourth parameter set containing a 120 kHz subcarrier spacing (e.g., μ=3).

[0062] Figure 2 This description illustrates an example of a processor 200 supporting sidelink positioning using a reference anchor UE according to aspects of this disclosure. Processor 200 may be an example of a processor configured to perform various operations according to the examples described herein. Processor 200 may include a controller 202 configured to perform various operations according to the examples described herein. Processor 200 may optionally include at least one memory 204, such as an L1 / L2 / L3 cache. Additionally or alternatively, processor 200 may optionally include one or more arithmetic logic units (ALUs) 200. One or more of these components may be electronically communicated or otherwise coupled (e.g., operational ground, communication ground, functional ground, electronic ground, electrical ground) via one or more interfaces (e.g., buses).

[0063] Processor 200 may be a processor chipset and includes a protocol stack (e.g., a software stack) executed by the processor chipset to perform various operations (e.g., receiving, obtaining, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, reading) according to the examples described herein. The processor chipset may include one or more cores, one or more caches (e.g., memory native to the processor chipset (e.g., processor 200) or contained within the processor chipset (e.g., processor 200) or other memory (e.g., random access memory (RAM), read-only memory (ROM), dynamic RAM (DRAM), synchronous dynamic RAM (SDRAM), static RAM (SRAM), ferroelectric RAM (FeRAM), magnetic RAM (MRAM), resistive RAM (RRAM), flash memory, phase-change memory (PCM), etc.).

[0064] Controller 202 can be configured to manage and coordinate various operations of processor 200 (e.g., signaling, receiving, acquiring, retrieving, transmitting, outputting, forwarding, storing, determining, identifying, accessing, writing, and reading) to enable processor 200 to support various operations according to examples described herein. For example, controller 202 can operate as a control unit of processor 200, thereby generating control signals that manage the operation of various components of processor 200. These control signals include enabling or disabling functional units, selecting data paths, initiating memory access, and coordinating the timing of operations.

[0065] Controller 202 may be configured to fetch (e.g., fetch, retrieve, receive) instructions from memory 204 and determine subsequent instructions to be executed to enable processor 200 to support various operations according to the examples described herein. Controller 202 may be configured to track the memory addresses of instructions associated with memory 204. Controller 202 may be configured to decode instructions to determine the operations to be performed and the operands involved. For example, controller 202 may be configured to interpret instructions and determine control signals to be output to other components of processor 200 to enable processor 200 to support various operations according to the examples described herein. Alternatively or additionally, controller 202 may be configured to manage data flow within processor 200. Controller 202 may be configured to control data transfers between registers, arithmetic logic unit (ALU), and other functional units of processor 200.

[0066] Memory 204 may include one or more caches (e.g., memory local to processor 200 or included in processor 200, or other memory such as RAM, ROM, DRAM, SDRAM, SRAM, MRAM, flash memory, etc.). In some embodiments, memory 204 may reside within or on the processor chipset (e.g., local to processor 200). In some other embodiments, memory 204 may reside outside the processor chipset (e.g., remote from processor 200).

[0067] Memory 204 may store computer-readable, computer-executable code containing instructions that, when executed by processor 200, cause processor 200 to perform the various functions described herein. The code may be stored in a non-transitory computer-readable medium, such as system memory or another type of memory. Controller 202 and / or processor 200 may be configured to execute the computer-readable instructions stored in memory 204 to cause processor 200 to perform various functions. For example, processor 200 and / or controller 202 may be coupled to or coupled to memory 204, and processor 200, controller 202, and memory 204 may be configured to perform the various functions described herein. In some instances, processor 200 may include multiple processors and memory 204 may include multiple memories. One or more of the multiple processors may be coupled to one or more of the multiple memories, which may be individually or collectively configured to perform the various functions described herein.

[0068] One or more ALUs 200 may be configured to support various operations according to the examples described herein. In some embodiments, one or more ALUs 200 may reside within or on a processor chipset (e.g., processor 200). In some other embodiments, one or more ALUs 200 may reside outside the processor chipset (e.g., processor 200). One or more ALUs 200 may perform one or more calculations on data, such as addition, subtraction, multiplication, and division. For example, one or more ALUs 200 may receive input operands and an opcode that determines the operation to be performed. One or more ALUs 200 may be configured with various logic and arithmetic circuitry, including adders, subtractors, shifters, and logic gates, to process and manipulate data according to the operation. Alternatively, one or more ALUs 200 may support logical operations such as AND, OR, XOR, NOR, and NAND, thereby enabling one or more ALUs 200 to handle conditional operations, comparisons, and bitwise operations.

[0069] Processor 200 may support wireless communication according to examples disclosed herein. Processor 200 may be configured or operable to support components for side-link positioning using a reference anchor UE.

[0070] Table 1 below lists examples of supported positioning technologies up to Rel-16 for RAT-related UL-based and DL-based positioning, as well as RAT-independent positioning.

[0071] [Table 1]

[0072]

[0073]

[0074] Based on the requirements of LMF and UE capabilities, different positioning technologies as indicated in Table 1 can currently be configured and executed. The transmission of Uu (uplink and downlink) positioning reference signals (PRS) enables the UE to perform UE positioning-related measurements to calculate the UE's absolute position estimate and is configured per transmit receiver point (TRP), where the TRP may contain one or more beams. Figure 3 The text provides a conceptual overview.

[0075] According to Rel-16, PRS can be transmitted using narrow beams within FR1 and FR2 by different base stations (serving and neighboring), such as Figure 3 As explained, this differs somewhat from LTE, where PRS is transmitted across the entire cell. PRS can be associated locally with the PRS resource ID and resource set ID of the base station (TRP). Similarly, UE positioning measurements (e.g., Reference Signal Time Difference (RSTD) and PRSRSRP measurements) are performed between beams (e.g., between different DL PRS resource pairs or DL ​​PRS resource sets), rather than between different cells as in LTE.

[0076] In addition, the network utilizes additional UL positioning methods to calculate the location of the target UE. Tables 2 and 3 show the mapping from reference signals to measurements at the UE and gNB for at least some supported RAT-related positioning technologies, respectively. RAT-related positioning technologies may involve 3GPP RATs and core network entities to perform UE location estimation, which differs from RAT-independent positioning technologies that rely on GNSS, IMU sensors, WLAN, and Bluetooth technologies to perform target device (UE) positioning.

[0077] Figure 4 This is an overview of absolute and relative positioning scenarios using three different coordinate systems: 1) absolute positioning, fixed coordinate system; 2) relative positioning, variable and moving coordinate system; and 3) relative positioning, variable coordinate system.

[0078] [Table 2]

[0079]

[0080]

[0081] [Table 3]

[0082]

[0083] RAT-related positioning measurements

[0084] Table 4 shows the different DL measurements, including downlink positioning reference signal-reference signal received power (DL PRS-RSRP), DL RSTD, and UE Rx-Tx time difference for supported RAT-related positioning technologies. The following measurement configurations are specified: 1) Four pairs of DL RSTD measurements can be performed per cell pair. Each measurement is performed between different pairs of DL PRS resources / resource sets with a single reference timing. 2) Eight DL PRS RSRP measurements can be performed on different DL PRS resources from the same cell.

[0085] [Table 4]

[0086]

[0087]

[0088]

[0089] SL PRS resource configuration and allocation

[0090] SL positioning is based on SL PRS transmitted via the PC5 interface. SL PRS resources are pseudo-random sequences that are mapped to time-frequency resources (OFDM symbol pairs, subcarriers) within the time slots of the radio frames used for SL PRS transmission. Multiple SL PRS resources can be configured within the SL BWP by a certain number of resource pools.

[0091] The resource pool can contain a certain number of consecutive PRBs and consecutive or non-consecutive time slots. In the frequency domain, the resource pool is further divided into a certain number of consecutive sub-channels, where each sub-channel consists of a group of N consecutive PRBs in a time slot. A sub-channel represents the smallest unit used for SL data transmission or reception. Furthermore, the SL PRS resource pool can be configured as a shared resource pool or a dedicated resource pool. A shared resource pool can be used to transmit both SL PRS and the Physical Side Link Shared Channel (PSSCH), while a dedicated resource pool can be used solely for transmitting SL PRS.

[0092] Figure 5 This describes the instance configuration of SL PRS resources within the SL BWP. Generally, three resource pools for SL PRS are configured within the SL BWP (RP1 to RP3), and the configuration of each resource pool repeats over a given periodicity. For resource pool RP1, 12 sub-channels are defined, and each sub-channel consists of a group of 10 consecutive PRBs in a time slot.

[0093] Regarding resource allocation for SL PRS, the following schemes are supported.

[0094] Scheme 1 / Mode 1 refers to network-controlled SL PRS resource allocation, in which the gNB manages and schedules the transmission of SL PRS resources. According to this scheme, the UE transmitting SL PRS sends a request to the gNB for specific SL PRS resource characteristics / SL-PRS resource configuration, and receives SL-PRS resource allocation signaling from the gNB via dynamic authorization (provided via DCI), configured authorization type 1 (provided via RRC), or configured authorization type 2 (provided via PDCCH). The request from the UE can be sent to the gNB via the L2 MAC control element (CE) or RRC messages.

[0095] Scheme 2 / Mode 2 refers to UE-autonomous SL PRS resource allocation, in which the UE autonomously selects SL PRS resources for transmission. According to this scheme, the UE first defines a selection window (a certain number of time slots) and identifies candidate SL PRS resources within the selection window. Then, during the defined sensing window (a certain number of time slots), the UE senses the identified candidate SL PRS resources to determine which SL PRS resources are available. Finally, the UE randomly selects an SL PRS resource from the set of available SL PRS resources. SLPRS transmission can be triggered by the UE itself, or UE-A can request UE-B to transmit SL-PRS via L1-side Link Control Information (SCI) or L2 MAC CE.

[0096] Option 1 is intended for scenarios with and within coverage area, while Option 2 is intended for scenarios outside coverage area. The UE can be configured via broadcast signaling (SIB12) or dedicated signaling (RRCReconfiguration message) to implement resource allocation option 1 and / or option 2 applicable to all resource pools (dedicated or shared resource pools).

[0097] Network-based SL positioning

[0098] Figure 6 This demonstrates an example message flow of a sidelink mobile terminal location request (SL-MT-LR) procedure, where the network is involved and the absolute location of UE1 is determined using an SL PRS transmitted from UE2 to UEn. UE1 is the target UE, and UE2 to UEn are anchor UEs. It is assumed that all involved UEs are within coverage area and served by the same gNB.

[0099] In step 0, AMF obtains data from an external LCS client ( Figure 6(Not shown) UE1 receives a request for its current absolute location. In step 1, based on the requested LCS QoS in the LCS service request, the AMF initiates SL positioning and sends an SL-MT-LR request to UE1. In step 2, based on the received SL-MT-LR request, UE1 initiates an SL discovery process and attempts to discover other UEs, such as UE2 to UEn. In step 3, upon discovering UE2 to UEn, UE1 obtains their SL positioning capabilities, such as supported SL positioning modes, positioning methods, UE roles (i.e., anchor UEs), and their (pre)configured (if any) SL PRS resource pools. In step 4, UE1 sends an SL-MT-LR response to the AMF, containing information about the discovered UE2 to UEn, their SL positioning capabilities, and (pre)configured (if any) SL PRS resource pools. The AMF forwards the SL-MT-LR response to the LMF.

[0100] In step 5, the LMF triggers an SL positioning procedure for UE1 and the discovered UE2 to UEn. Based on the received SL-MT-LR response, the LMF performs UE-assisted positioning to determine the location of UE1 according to the SL-TDoA and UE2 to UEn as anchor UEs. Furthermore, during this procedure, the LMF sends SL positioning assistance data to UE1 to UEn. The assistance data to UE1 contains information about SL PRS resources that can be requested from each UE2 to UEn. The assistance data to each UE2 to UEn contains information about SL PRS resources requested to be transmitted to UE1. Based on the received assistance data, UE1 to UEn performs SL positioning against the SL-TDoA. UE1 performs SL PRS measurements based on the SL PRS received from UE2 to UEn and sends the measurement results to the LMF. In step 6, the LMF then calculates the absolute position of UE1 based on the SL PRS measurements received from UE1 and sends a position estimate to the AMF.

[0101] SL positioning based on UE only

[0102] Figure 7 This demonstrates an example message flow of a sidelink mobile originating location request (SL-MO-LR) procedure, where the network is not involved and the absolute location of the target UE is determined using an SL PRS transmitted from anchor UE1 to UEn. It is assumed that all involved UEs are outside coverage and that the target UE does not have the SL location server functionality that would enable it to perform location calculations.

[0103] In step 0, the target UE receives a request for its current absolute location from an external LCS client. In step 1, the target UE initiates SL positioning based on the requested LCS QoS in the LCS service request and begins the SL discovery process to discover nearby anchor and serving UEs. Assume the target UE can discover anchor UEs 1 through UEn and a server UE. In step 2, the target UE, anchor UEs 1 through UEn, and the server UE perform an SL positioning capability exchange. This means the target UE acquires the SL positioning capabilities of anchor UEs 1 through UEn and the server UE, such as supported SL positioning modes, positioning methods, and their pre-configured (if any) SL PRS resource pools.

[0104] In step 3, based on the results of the SL positioning capability exchange in step 2, the target UE decides to perform UE-assisted positioning based on SL-TDOA and use the server UE to perform location calculation. The target UE then sends SL positioning assistance data to the anchor UEs. The assistance data to each anchor UE1 to UEn contains information about the SL PRS resources requested to be transmitted to the target UE.

[0105] In step 4, the anchor UE performs SL PRS measurement based on the received auxiliary data transmission SL PRS, and the target UE performs SL PRS measurement based on the SL PRS received from the anchor UE. In step 5, the target UE sends the measurement result to the server UE using the SL Provided Location Information Message. In step 6, based on the SL PRS measurement received from the target UE, the server UE then calculates the absolute position of the target UE and sends back a position estimate using the SL Provided Auxiliary Data Message.

[0106] Figure 8 This illustration provides an example of a block diagram of an apparatus 802 supporting sidelink positioning using a reference anchor UE according to aspects of this disclosure. Apparatus 802 may be an instance of an LMF server or UE 104 as described herein. An LMF server may be any physical entity associated with a location function (e.g., LMF) and may be network entity 102, core network server 106, etc. Apparatus 802 may support wireless communication with one or more network entities 102, UE 104, or any combination thereof. Apparatus 802 may include components for bidirectional communication, including components for transmitting and receiving communications, such as processor 804, memory 806, transceiver 808, and I / O controller 810. These components may communicate electronically or be otherwise coupled (e.g., operational ground, communication ground, functional ground, electronic ground, electrical ground) via one or more interfaces (e.g., buses).

[0107] Processor 804, memory 806, transceiver 808, or various combinations thereof, or various components thereof, may be instances of components for performing various aspects of the present disclosure as described herein. For example, processor 804, memory 806, transceiver 808, or various combinations thereof, or components thereof, may support methods for performing one or more of the operations described herein.

[0108] In some embodiments, processor 804, memory 806, transceiver 808, or various combinations or components thereof, may be implemented in hardware (e.g., as a communication management circuitry system). The hardware may include processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination thereof, configured to or otherwise support components for performing the functions described herein. In some embodiments, processor 804 and memory 806 coupled to processor 804 may be configured to perform one or more of the functions described herein (e.g., instructions stored in memory 806 are executed by processor 804).

[0109] For example, processor 804 may support wireless communication at device 802 according to examples disclosed herein. Processor 804 may be configured or otherwise support components for side-link positioning using a reference anchor UE.

[0110] Processor 804 may include intelligent hardware devices (e.g., general-purpose processors, DSPs, CPUs, microcontrollers, ASICs, FPGAs, programmable logic devices, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some embodiments, processor 804 may be configured to operate a memory array using a memory controller. In some other embodiments, the memory controller may be integrated into processor 804. Processor 804 may be configured to execute computer-readable instructions stored in memory (e.g., memory 806) to cause device 802 to perform various functions of this disclosure.

[0111] Memory 806 may include random access memory (RAM) and read-only memory (ROM). Memory 806 may store computer-readable, computer-executable code containing instructions that, when executed by processor 804, cause device 802 to perform the various functions described herein. The code may be stored in a non-transitory computer-readable medium, such as system memory or another type of memory. In some embodiments, the code may not be directly executable by processor 804, but may enable a computer (e.g., when compiled and executed) to perform the functions described herein. In some embodiments, memory 806 may, in particular, include a basic I / O system (BIOS) that controls basic hardware or software operation, such as interaction with peripheral components or devices.

[0112] I / O controller 810 manages the input and output signals of device 802. I / O controller 810 can also manage peripheral devices not integrated into device 802. In some embodiments, I / O controller 810 may represent a physical connection or port to an external peripheral device. In some embodiments, I / O controller 810 may utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS / 2®, UNIX®, LINUX®, or another known operating system. In some embodiments, I / O controller 810 may be implemented as part of a processor (e.g., processor 804). In some embodiments, a user may interact with device 802 via I / O controller 810 or via hardware components controlled by I / O controller 810.

[0113] In some embodiments, device 802 may include a single antenna 812. However, in other embodiments, device 802 may have more than one antenna 812 (i.e., multiple antennas), including multiple antenna panels or antenna arrays, which may be capable of transmitting or receiving multiple wireless transmissions simultaneously. Transceiver 808 may communicate bidirectionally via one or more antennas 812, wired or wireless links, as described herein. For example, transceiver 808 may represent a wireless transceiver and be capable of bidirectional communication with another wireless transceiver. Transceiver 808 may also include a modem to modulate packets, provide the modulated packets to one or more antennas 812 for transmission, and demodulate packets received from one or more antennas 812.

[0114] This disclosure details a solution for selecting and configuring a reference anchor UE to support SL-TDoA configuration. In various embodiments, the reference UE can be selected and managed, and its location can be calculated with or without an LMF. The calculation of the target UE's location and other functions that would normally be handled by the LMF can be handled by a server UE instead of the LMF. Therefore, a server UE is a UE assigned to provide functionality similar to that of an LMF used to perform the SL-TDoA procedure. The server UE can be co-located with either the target UE or the anchor UE.

[0115] The embodiments relate to various aspects of SL positioning measurements, including procedures for managing reference UE selection in network-based SL positioning scenarios involving a target UE, participating SL positioning UEs (e.g., anchor UEs, and location servers, e.g., LMFs); procedures for managing reference UE selection in UE-only SL positioning scenarios involving a target UE and participating SL positioning UEs (which may be referred to as anchor UEs); procedures for enabling dedicated SL-PRS configurations for reference anchor UEs; and procedures for distinguishing between network-based positioning operations and UE-only positioning operations for reference anchor UEs.

[0116] For the purposes of this disclosure, a Positioning Related Reference Signal (PRS) may be referred to as a reference signal used in the positioning process to estimate the location of a target UE, or based on an existing reference signal (e.g., CSI-RS or SRS), and the target UE may be referred to as the device to be located. In various embodiments, the term 'PRS' may refer to a signal such as a reference signal, which may or may not be primarily used for positioning. Furthermore, the location or positioning of the UE may refer to an absolute location, a relative location with respect to another node, a distance range, a direction range, or a combination thereof.

[0117] Figure 9 This illustration illustrates an example of schematic diagram 900, which demonstrates side-link localization using a reference anchor UE in support of aspects of this disclosure.

[0118] When selecting one or more positioning methods, including SL-TDoA measurements, based on one or more SL-RSTD measurements, an active reference anchor UE is selected in a network-based positioning scenario. Network-based positioning operations for sidelink positioning may involve one or more 5GC functions, including LMF, which handles location service request management and provides configuration assistance information, and performs final location estimation calculations. Alternatively, as... Figure 9 As shown, the location entity can be the server UE, rather than the LMF.

[0119] The target UE can share a list of candidate anchor UEs with the LMF or server UE via signaling 902 (e.g., SLPP or LPP signaling) (e.g., in an SLPPRequestAssistanceData message), or in other implementations, utilize supplementary service messages that act as containers for carrying SLPP or LPP messages. The list of candidate anchor UEs can be obtained by the target UE using a set of sidelink location discovery procedures performed by the target UE or server UE.

[0120] Each of the listed candidate anchor UEs 1) may have associated location information, or 2) may not have associated location information. Location information may include one or more of the following: absolute horizontal position (2D position), absolute vertical position (3D position), relative horizontal and / or vertical position, horizontal and / or vertical distance relative to one or more UEs, and direction relative to one or more UEs. If location information for one or more UEs is not provided at 902, the LMF may prioritize anchor UEs with associated location information. If location information is not provided to candidate anchor UEs, the LMF may, for example, initiate a location retrieval process for such anchor UEs using a Mobility Termination Location Request (MT-LR) procedure and associated LPP signaling. At 902, each of the associated SL positioning capabilities of the candidate anchor UEs, along with the candidate anchor UE information, may also be signaled to the LMF.

[0121] In this embodiment, the LMF initiates a conventional location service request to the potential anchor UE, and the LMF receives a response from the potential anchor UE to participate in the location retrieval process. The LMF determines the location of the potential anchor UE to which the LMF has sent a location service request. In this case, the LMF may prioritize the anchor UE based on the time it receives a positive acknowledgment of the location retrieval request from the anchor UE, the location proximity of the anchor UE to the target UE, any previously received Rx measurement information of the anchor UE relative to the target UE, or any combination thereof.

[0122] When the location calculation entity is a server UE, the server UE can, for example, use an additional SL positioning procedure based on SLPP signaling to initiate the location retrieval process for such anchor UEs. A list of candidate anchor UEs can be obtained using the SL positioning discovery procedure, and additionally, at 902, each of the associated SL positioning capabilities of the candidate anchor UEs, along with the candidate anchor UE information, can be signaled to the server UE via the SLPP capability exchange procedure.

[0123] At 906, the LMF, server UE, or target UE selects a set of active anchor UEs. There are several possible implementations for the selection of active anchor UEs. In one embodiment, the LMF or server UE selects an initial anchor UE from a list of candidate anchor UEs received at 902 for the configured SLPP session associated with the SLPP session ID, and at 904, signals the initial anchor UE list to the target UE, for example, using an SLPPProvideAssistanceData message. Then, at 906, the target UE may select anchor UEs based on the initial list provided by the LMF or server UE, and these anchor UEs may be considered active anchor UEs used for lateral link positioning, for example, to perform SL-TDoA. In another embodiment, the LMF or server UE may select an active anchor UE from candidate UEs.

[0124] In another embodiment, the target UE performs a final anchor UE selection based on a list of candidate anchor UEs, and notifies the LMF or server UE of the anchor UE ultimately selected from the list. The final selected anchor UE can be considered an active anchor UE.

[0125] The final selected anchor UE or active anchor UE may be used for the entire duration of an active SLPP session unless one or more active anchor UEs are reselected due to reasons such as changes in radio channel conditions, anchor UE mobility relative to the target UE, anchor UE becoming unreachable via the SL (PC5) interface, anchor UE being outside coverage area, etc.

[0126] At position 908, the target UE and the anchor UE ( Figure 9 A sidelink connection is established between UE1 and UEn, and an appropriate procedure is initiated based on the type of positioning method (e.g., SL-TDoA). At 910, the target UE, LMF, or server UE performs reference anchor UE selection and / or derives a reference anchor UE list using one or more selection criteria. For example, the target UE, LMF, or server UE may select an active reference anchor UE from an active anchor UE list to associate the reported SL-RSTD measurement set within an ongoing SLPP session. In other embodiments, the same reference anchor UE may be maintained across different SLPP sessions, depending on applicable conditions. The selection criteria used by the target UE, LMF, or server UE to select one or more reference anchor UEs may include one or more of the following criteria. When the LMF or server UE selects a reference anchor UE, the reference anchor UE may be selected from a set of active anchor UEs received from the UE at 906.

[0127] The first criterion can be based on previously measured crosslink location or on reference signal measurements from one or more transmissions from the SL anchor UE. Examples of signal measurements are measurements from the target device's Physical Side Crosslink Broadcast Channel (PSBCH)-RSRP, PSSCH-RSRP, Physical Side Crosslink Control Channel (PSCCH)-RSRP, SL PRS RSRP, SL PRS RSRPP, and SLRSSI. For example, the reference anchor UE can be selected based on a configured measurement threshold, such that if the target UE performs measurements above the configured threshold, it is more likely that the associated anchor UE will be selected as the reference anchor UE.

[0128] The second criterion is the line-of-sight (LOS) status based on SL positioning measurements, which indicates whether a potential reference anchor device has a LOS link relative to the target UE. The target UE is more likely to select the anchor UE as the reference anchor UE, which has LOS measurements.

[0129] The third criterion is based on whether the anchor UE supports time difference procedures. For example, in one embodiment, this criterion includes whether the anchor UE must support the SL-TDoA positioning procedure. In other embodiments, this criterion may consider whether the candidate reference anchor UE also supports SL-RToA or SL-ToA methods based on SL-RToA measurements.

[0130] The fourth criterion is based on whether the 2D or 3D position information of the anchor UE is known. This criterion may favor UEs whose absolute horizontal and / or vertical position information is available. If the UEs are too far apart, time synchronization becomes difficult, and in some cases, the reference signal may be invalid / inaccurate when the distance is too great. Therefore, for the selection of the reference anchor UE, a position close to the target UE may be considered advantageous.

[0131] The fifth criterion is based on the coverage status of the anchor UE. This criterion favors UEs within the coverage area of ​​the same network as the target UE, and further favors UEs within the coverage area of ​​the same gNB or cell as the target UE. Coverage status can be provided via flags using SLPP signaling or higher-level signaling (e.g., from the application layer or ranging / SL positioning layer or the layer performing UE discovery). Sidelink time difference measurements typically use synchronization procedures, and synchronization is more easily achieved when the target and reference anchor UEs share coverage and the same synchronization source (e.g., GNSS, network time (gNB), or the same UE synchronization time).

[0132] The sixth criterion is based on Public Land Mobile Network (PLMN) related information of the anchor UE. PLMN information may include at least a PLMN ID, which is a 6-digit identifier containing a Mobile Country Code (MCC) and a Mobile Network Code (MNC). This criterion may favor UEs with the same PLMN ID as the target UE.

[0133] The seventh criterion is that the candidate reference anchor UE is defined with an anchor UE role and this is indicated to the target UE. This indication may be transmitted as part of the UE's capability information or as part of discovery metadata information.

[0134] At 912, the target UE transmits the identity of the active reference anchor UE and / or a list of reference anchor UEs to the LMF or server UE. The ultimately selected reference anchor UE may also be referred to as the active reference anchor UE. In some embodiments, the target UE may implement the above selection criteria to provide a list of reference anchor UEs, where {list of reference anchor UEs} ≤ {total number of active anchor UEs}. Instantaneous signaling, such as the SLPPRequestAssistanceData message, can be used to provide the selected active reference anchor UE or the list of reference anchor UEs to the LMF or server UE.

[0135] As described above, in this embodiment, the target UE transmits a list of reference anchor UEs to the LMF or server UE, rather than simply transmitting the identity of a single active reference anchor UE. The selection of reference anchor UEs can be dynamic and is not limited to a single anchor UE throughout the SLPP session. Furthermore, the selection of reference UEs can be detailed to describe the reference anchor UE selection process, or, in other embodiments, for flexibility, the selection criteria can be left to the UE implementation. The LMF or server UE can use the list of reference anchor UEs to select different active reference anchor UEs at a later time, which can be done within the same SLPP session or in subsequent SLPP sessions.

[0136] The reference anchor UEs in the reference anchor UE list can be sorted according to either an explicit priority indicator or an implicit priority indicator. In the case of an implicit priority order, the reference anchor UEs can be sorted in descending order of their appearance in the list, corresponding to a descending priority order; that is, the first reference anchor UE in the list has the highest priority (and can be the active reference anchor UE), the second reference anchor UE has the second priority, and so on. In another embodiment, an ascending priority order can also be used. The priority list can be determined by the target UE based on the selection criteria described above.

[0137] In another embodiment, a reference anchor device flag (indication) may be associated with the anchor UE, wherein a value of '0' indicates that it is not the reference anchor UE or a value of '1' indicates that the anchor UE is the reference anchor UE. This can be signaled to the LMF or server UE via an indication in a signal transmitted at 912 (e.g., an SLPP RequestAssistanceData message) or based on a supplemental service message (e.g., SL-MT-LR).

[0138] At 914, the LMF or server UE can provide dedicated auxiliary data to the active reference anchor UE. Figure 9 In this context, UE2 is designated as the active reference anchor UE and receives this auxiliary data. An example of data that can be transmitted to the active reference anchor UE is SL-PRS information, including the SL-PRS resource ID, SL-PRS periodicity, comb size and comb size offset, number of symbols, and dedicated SL-PRS or shared resource pool information, i.e., both the SL-PRS and the PSSCH including Phase 2 SCI and / or sidelink shared channel (SL-SCH) data. In another embodiment, the serving gNB may also provide dedicated resource grants to the reference anchor UE, for example, configured Type 1 or Type 2 grants.

[0139] At 916, the target UE performs SL-RSTD measurements based on the active reference anchor UE.

[0140] Figure 10A and 10B This is an example conceptual diagram illustrating the role of a reference anchor UE in deriving SL-RSTD measurements in a network-based positioning scenario supporting side-link positioning using a reference anchor UE, according to aspects of this disclosure. Although at time t1, the reference anchor UE is... Figure 10A UE 104a in the reference UE, but at a later time t2, the reference anchor UE is... Figure 10B UE 104c in the example. Therefore, as will be explained in more detail below, the reference anchor UE of the target UE 104T can change even within the same SLPP session.

[0141] exist Figure 10A and 10B In this process, the target UE 104T receives an SL-PRS signal from each of the anchor UEs 104a, 104b, and 104c, one of which is designated as a reference anchor UE. The target UE 104T then generates an SL-RSTD measurement based on the SL-PRS signal and associates the measurement with the corresponding transmitting UE. In this embodiment, each of the SL-RSTD measurements is based on a first Time of Arrival (ToA) measurement between the target UE 104T and the reference anchor UE, and a second Time of Arrival (ToA) measurement between the target UE and an anchor UE from the set of active anchor UEs.

[0142] For example, in Figure 10A In this process, the UE can generate a first SL-RSTD measurement using the ToA measurements of reference UE 104a and another anchor UE 104b, and generate a second SL-RSTD measurement using the ToA measurements of reference UE 104a and another anchor UE 104c. Therefore, each of the SL-RSTD measurements generated by the target UE 104T is based on measurements from the reference anchor UE (…). Figure 10A UE 104a and Figure 10B ToA measurement of SL-PRS in UE 104C.

[0143] At location 918, the target UE reports the SL-RSTD measurement from 916 to location entity 1002. Location entity 1002 is... Figure 9 The target UE may be an LMF or server UE. The data reported by the target UE may include reference anchor UE information, such as the UEID associated with the measurement. Alternatively, in this example, for UE-based positioning, the target UE processes the SL-RSTD measurement at 916 and calculates the requested location information received from the internal LCS client or application within the UE.

[0144] At point 920, the target UE, based in part on the selection criteria described above, performs the update of the selected reference anchor UE and / or updates the list of reference anchor UEs. (See again...) Figure 10B It can be seen that the positions of anchor UEs 104a, 104b, and 104c relative to the target UE 104T have changed. Therefore, when Figure 10B When the target UE 104T re-evaluates the anchor UE using selection criteria, the target UE 104T determines that UE 104c is more suitable as a reference anchor UE and designates UE 104c as the new reference anchor UE. In this embodiment, the target UE updates the reference anchor UE list using selection criteria. At 922, the target UE transmits the updated active reference anchor UE and / or the updated reference anchor UE list to the LMF or server UE.

[0145] At position 924, the LMF or server UE can provide the updated dedicated auxiliary data to the new reference anchor UE. Figure 9 In the middle, the new reference anchor UE is UE1, while... Figure 10BIn this context, the new reference anchor UE is 104c. The updated dedicated auxiliary data may include one or more of the SL-PRS information, including the SL-PRS resource ID, DL-PRS periodicity, comb size and comb size offset, number of symbols, and dedicated SL-PRS or shared resource pool information (both the SL-PRS and the PSSCH including Phase 2 SCI and / or SL-SCH data). In another embodiment, the serving gNB may also provide dedicated resource grants to the reference anchor UE, for example, configured Type 1 or Type 2 grants.

[0146] At position 926, the target UE is based on the updated active reference anchor UE (which is... Figure 9 UE 1 and Figure 10B UE104c in the UE performs SL-RSTD measurements. Except for the reference anchor UE used for SL-RSTD measurements, which is the updated reference anchor UE from 926 ( Figure 9 UE1 and Figure 10B Apart from UE 104c), this step is essentially the same as 918 discussed above. At 928, the target UE reports the SL-RSTD measurement from 926 to the LMF or server UE based on the active reference anchor UE. Alternatively, for UE-based positioning, the target UE processes the SL-RSTD measurement and calculates the requested location information. At 930, the LMF or server UE calculates the target UE's location using the SL-RSTD data received from the UE at 918 or 928. The SL-RSTD data at these two steps represents data collected at two different times, therefore the location will be calculated at each time.

[0147] Reference anchor UE configuration

[0148] In the embodiments, in mode 1, the network may configure shared or dedicated SL positioning assistance data for the active reference anchor UE, or in mode 2, the network may utilize a shared resource pool for sensing and resource selection or receive a dedicated resource set from another UE (e.g., a server UE). Table 5 shows a list of exemplary SL-PRS configuration parameters that can be configured for the reference anchor UE, and this list may be applicable to dedicated SL-PRS resource pools and / or shared resource pools.

[0149] [Table 5]

[0150]

[0151] Additionally, relative time difference (RTD) information used to mitigate potential synchronization errors can be applied with respect to the selected active reference anchor UE. The relative time difference between UE i and the reference anchor UE j can be defined as t. j -t i , where t i and tj It is defined as the start time of the transmission of a side link subframe / slot by UE i and reference anchor UE j respectively.

[0152] The relative time between anchor UE i and reference anchor UE j can be represented by the SL-PRS offset, which can be signaled to the target UE using one or more of the following parameters:

[0153] 1) System frame number (SFN) #0 and slot #0 for scenes within the coverage area, which has gNB coverage.

[0154] SFN Offset: The parameter sfn-Offset specifies the SFN offset between the SL positioning auxiliary data of reference anchor UE j and anchor UE i at the UE antenna position. This offset corresponds to the number of complete radio frames counted from the start of radio frame #0 of the auxiliary data reference anchor UE j to the start of the most recent subsequent radio frame #0 of this anchor UE i.

[0155] Integer Subframe Offset: The parameter integerSubframeOffset specifies the frame boundary offset between the auxiliary data reference anchor UE j and another anchor UE i counted in the full subframe at the UE antenna position. This offset corresponds to the number of full subframes counted from the start of subframe #0 of the auxiliary data reference anchor UE j to the start of the nearest subsequent subframe #0 of this other anchor UE i.

[0156] 2) Direct Frame Number (DFN) #0 and Time Slot #0 are used for scenes outside the coverage area, where the DFN, subframe number and time slot number within the frame are derived using the current UTC time.

[0157] DFN Offset: The parameter dfn-Offset specifies the DFN offset between the SL positioning auxiliary data of reference anchor UE j and another anchor UE i at the UE antenna position. This offset corresponds to the number of complete radio frames counted from the start of radio frame #0 of auxiliary data reference anchor UE j to the start of the most recent subsequent radio frame #0 of this anchor UE i.

[0158] Integer Subframe Offset: The parameter integerSubframeOffset specifies the frame boundary offset between the auxiliary data reference anchor UE j and another anchor UE i counted in the full subframe at the UE antenna position. This offset corresponds to the number of full subframes counted from the start of subframe #0 of the auxiliary data reference anchor UE j to the start of the nearest subsequent subframe #0 of this other anchor UE i.

[0159] The aforementioned RTD and the relative time offset information between the reference anchor UE and another anchor UE can be used as part of SL positioning assistance, such as SLPP ProvideAssistanceData, which is signaled from the server UE to the target UE. Figure 9 Transmissions at positions 904, 914, and 924.

[0160] Reference Anchor UE Device ID Management

[0161] In various embodiments, a number of ID options can be used to enable the LMF or server UE to distinguish a specific reference anchor device in a specific SLPP session of a network-based positioning scenario, wherein one or more combinations of IDs can be used. Additionally, a number of ID options are provided for distinguishing the reference anchor UE in UE-only operation. A list of ID options is shown below in Table 6.

[0162] [Table 6]

[0163]

[0164]

[0165] Additionally, the flag can be associated with the anchor UE and / or reference anchor UE to indicate whether the UE is active. For example, a value of '0' can indicate that the anchor UE and / or reference anchor UE is inactive, while a value of '1' can indicate that the anchor UE and / or reference anchor UE is active.

[0166] In an embodiment, the LMF or AMF can create a mapping between the UE ID (e.g., 5G TMSI ID) and the source ID and destination ID, or the application layer ID, to distinguish different transmitting and receiving UEs. Since the LMF is unaware of the association between the source ID and the destination ID, this mapping can be explicitly provided via SLPP signaling or implicitly derived based on a temporary identifier of the LMF and the indicated source ID and destination ID.

[0167] In this embodiment, active reference anchor UE ID information can be transmitted in the SL positioning measurement report, which includes SL-RSTD measurements performed for a given active reference anchor UE. In a given SLPP session, the UE can report multiple SL-RSTD measurement sets associated with different reference anchor UEs, for example, SL-RSTD measurement set 1 associated with reference anchor UE 1, SL-RSTD measurement set 2 associated with reference anchor UE 2, and so on. One or more of the aforementioned reference anchor UE information can be used to associate SL-RSTD measurement sets in the SL positioning measurement report. Instantiation signaling for these reference anchor UE IDs can be included in SLPP signaling, such as SLPP ProvideLocationInformation or SL-TDOA-SignalMeasurementInformation messages. (Reference) Figure 9 This information can be transmitted at 918 and 928.

[0168] In this embodiment, the aforementioned UE ID information may be associated with the anchor UE as part of any of the reported SL-PRS-based positioning measurements, including SL-RTOA, UE Rx-Tx time difference, and SL-AOA. Instantiatory signaling for these reference anchor UE IDs may be included in SLPP signaling, for example, the SLPPProvideLocationInformation messages provided at 918 and 928.

[0169] Regarding the above aspects of the SL positioning measurement report, an SL positioning measurement report including one or both of the reference anchor UE and the anchor UE ID can be transmitted to the LMF for network-based positioning. For UE-only positioning, an SL positioning measurement report containing reference anchor UE and / or anchor UE ID information can be transmitted to another UE (e.g., server UE, anchor UE, or target UE).

[0170] Figure 11 A flowchart illustrating method 1100 for side-link positioning using a reference anchor UE, in accordance with aspects of this disclosure, is provided. Operation of method 1100 may be implemented by means or components thereof as described herein. For example, operation of method 1100 may be performed by means such as reference anchor UE. Figure 1 , 2 The UE 104 described in 9, 10A, and 10B is executed. In some embodiments, the device may execute a set of instructions to control the functional elements of the device to perform the described functions. Alternatively, the device may use dedicated hardware to perform aspects of the described functions.

[0171] At 1105, the method may include receiving an initial list of anchor UEs. The operation of 1105 may be performed according to the examples described herein. In some embodiments, aspects of the operation of 1105 may be as described in references... Figure 1 The described device performs this action. (As mentioned above...) Figure 9 Operation 904 explains how to receive the initial list of anchor UEs from the LMF or server UE.

[0172] At 1110, the method may include selecting a set of active anchor UEs from an initial anchor UE list using one or more selection criteria. The operation of 1110 may be performed according to the examples described herein. In some embodiments, aspects of the operation of 1110 may be as described in references... Figure 1 The described device performs the operation. Selecting a set of active anchor UEs from the initial anchor UE list is as described above. Figure 9 The operation is performed as explained in 906.

[0173] At 1115, the method may include selecting a reference anchor UE from the set of active anchor UEs. The operation of 1115 may be performed according to the examples described herein. In some embodiments, aspects of the operation of 1115 may be determined by reference to... Figure 1 The described device performs this function. Selecting a reference anchor UE from the set of active anchor UEs using one or more selection criteria can be as described above. Figure 9 The operation is performed as explained in 910.

[0174] At 1120, the method may include performing one or more side-link positioning measurements relative to a reference anchor UE. The operation of 1120 may be performed according to examples as described herein. In some embodiments, aspects of the operation of 1120 may be determined by, as in the reference... Figure 1 The described device performs the following. One or more side-link positioning measurements relative to the reference anchor UE can be performed as described above. Figure 9 The operation is performed as explained in 916.

[0175] At 1125, the method may include transmitting information about one or more sidelink positioning measurements and reference anchor UEs to a location computing entity. The operation of 1125 may be performed according to the examples described herein. In some embodiments, aspects of the operation of 1125 may be as described in references... Figure 1 The described device performs this function. Transmitting one or more sidelink positioning measurements and reference anchor UE information to the location calculation entity can be done as described above regarding... Figure 9 Perform the operations as explained in 918 and 928.

[0176] Figure 12A flowchart illustrating method 1200 for side-link positioning using a reference anchor UE in support of aspects of this disclosure is provided. Operation of method 1200 may be implemented by the apparatus or components thereof described herein. For example, operation of method 1200 may be performed by a reference anchor UE. Figure 1 , 2 The LMF or server UE described in 9, 10A, and 10B is executed. In some embodiments, the apparatus may execute a set of instructions to control the functional elements of the apparatus to perform the described functions. Alternatively, the apparatus may use dedicated hardware to perform aspects of the described functions.

[0177] At 1205, the method may include transmitting an initial list of anchor UEs to the target UE. The operation of 1205 may be performed according to the examples described herein. In some embodiments, aspects of the operation of 1205 may be as described in references... Figure 1 The described device performs this action. (As mentioned above...) Figure 9 As explained in operation 904, the initial anchor UE list is transmitted to the target UE.

[0178] At 1210, the method may include receiving a set of active anchor UEs from an initial anchor UE list from the target UE. The operation of 1210 may be performed according to the examples described herein. In some embodiments, aspects of the operation of 1210 may be as described in references... Figure 1 The described device performs the operation. Receiving a set of active anchor UEs from the initial anchor UE list can be done as described above. Figure 9 The operation is performed as explained in 906.

[0179] At 1215, the method may include selecting a reference anchor UE from the set of active anchor UEs. The operation of 1115 may be performed according to the examples described herein. In some embodiments, aspects of the operation of 1215 may be determined by reference to... Figure 1 The described device performs this function. Selecting a reference anchor UE from the set of active anchor UEs using one or more selection criteria can be as described above. Figure 9 The operation is performed as explained in 910.

[0180] At 1220, the method may include receiving a leglink positioning measurement from the target UE. The operation of 1220 may be performed according to the examples described herein. In some embodiments, aspects of the operation of 1220 may be as described in references... Figure 1 The described device performs the operation. The link positioning measurement from the target UE receiving side can be performed as described above. Figure 9 The operation is performed as explained in 918.

[0181] At 1225, the method may include calculating the location of the target UE using side-link positioning measurements. The operation of 1225 may be performed according to the examples described herein. In some embodiments, aspects of the operation of 1225 may be as described in references... Figure 1 The described device performs this operation. The location of the target UE can be calculated using side-link positioning measurements as described above. Figure 9 The operation is performed as explained in 930.

[0182] It should be noted that the methods described herein describe possible implementations, and the operations and steps can be rearranged or otherwise modified, and other implementations are also possible. Furthermore, aspects from two or more methods can be combined.

[0183] The various illustrative frames and components described herein can be implemented or executed using a general-purpose processor, DSP, ASIC, CPU, FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware component or any combination thereof designed to perform the functions described herein. The general-purpose processor may be a microprocessor, but alternatively, the processor may be any processor, controller, microcontroller or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors incorporating a DSP core, or any other such configuration).

[0184] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored as one or more instructions or code on or transmitted over a computer-readable medium. Other examples and embodiments are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwired, or any combination thereof. Features implementing the functions may also be physically located in various locations, including distributed implementations such that portions of the functions are implemented in different physical locations.

[0185] Computer-readable media include both non-transitory computer storage media and communication media, wherein the communication media includes any media that facilitates the transfer of a computer program from one place to another. Non-transitory storage media can be any available medium accessible by a general-purpose or special-purpose computer. For example, and without limitation, non-transitory computer-readable media can include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, optical disc (CD) ROM or other optical disc storage devices, magnetic disk storage devices or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code elements in the form of instructions or data structures and is accessible by a general-purpose or special-purpose computer or a general-purpose or special-purpose processor.

[0186] Any connection may be appropriately referred to as computer-readable media. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable media. As used herein, disks and optical discs include CDs, laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, wherein disks typically reproduce data magnetically, while optical discs reproduce data optically using lasers. Combinations of the above are also included within the scope of computer-readable media.

[0187] As used herein (including in the claims), the word "or" as used in a list of items (e.g., a list of items beginning with phrases such as "at least one of...", "one or more of...", or "one or both of...") indicates an inclusive list, such that a list of at least one of, for example, A, B, or C represents A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Furthermore, as used herein, the phrase "based on" should not be construed as referring to a closed set of conditions. For example, an example step described as "based on condition A" may be based on both condition A and condition B without departing from the scope of this disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "at least partially based on". Additionally, as used herein (including in the claims), "set" may contain one or more elements.

[0188] When referring to network entities, the terms “transmit,” “receive,” or “communicate” can refer to any part of a network entity (e.g., a base station, CU, DU, RU) of the RAN that communicates with another device (e.g., directly or via one or more other network entities).

[0189] The descriptions herein, illustrated in conjunction with the accompanying drawings, depict exemplary configurations and do not represent all implementable or claim-scoped instances. The term "example" as used herein means "serving as an example, illustration, or description," not "preferred" or "superior to other examples." The detailed descriptions include specific details intended to provide an understanding of the described techniques. However, these techniques can be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form to avoid obscuring the concept of the described examples.

[0190] The description herein is provided to enable those skilled in the art to make or use this disclosure. Various modifications to this disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the scope of this disclosure. Therefore, this disclosure is not limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A user equipment (UE) for wireless communication, comprising: At least one memory; and At least one processor, coupled to and configured to enable the UE to: Use one or more selection criteria to select a reference anchor UE from a set of active anchor UEs; Perform side-link measurements for positioning relative to the selected reference anchor UE; and Transmit one or more of the following: a sidelink measurement report based at least in part on the sidelink measurement performed or information associated with the reference anchor UE.

2. The UE of claim 1, wherein the at least one processor is further configured to cause the UE to: List of anchor UEs; and Select a group of active anchor UEs from the anchor UE list. The anchor UE list is received from the server UE or the location management function (LMF), and one or more of the side link measurement reports or information associated with the reference anchor UE are transmitted to the server UE or the LMF.

3. The UE according to claim 2, wherein the anchor UE list is received in a message serving as a container for a carry-side link positioning protocol (SLPP) message, or wherein the anchor UE list is received in the SLPP message.

4. The UE of claim 1, wherein the one or more selection criteria include at least one of the following: Threshold of the side link reference signal; The line-of-sight (LoS) state associated with the UE or one or more of each of at least one of the group of active anchor UEs; Coverage status associated with the UE or one or more of each of at least one of the group of active anchor UEs; Whether the sidelink time difference of arrival (SL-TDoA) measurement is supported by the UE or one or more of each of the at least one active anchor UE in the group of active anchor UEs; Whether the position of each of at least one of the active anchor UEs in the set of active anchor UEs is available in the multidimensional space; and Public Land Mobile Network (PLMN) information associated with each active anchor UE in the set of active anchor UEs.

5. The UE of claim 1, wherein the at least one processor is further configured to cause the UE to: Sort each active anchor UE in the active anchor UE list; and Transmit the indication of the sorted active anchor UE.

6. The UE of claim 1, wherein the information associated with the reference anchor UE includes an identifier of the reference anchor UE.

7. The UE of claim 1, wherein the information associated with the reference anchor UE comprises one or more of the following: One or more side link reference signal time difference (SL-RSTD) measurements; Application layer identifier; Temporary Mobile Subscriber Identity (TMSI); Source identifier; Destination identifier; Anchor UE identifier; and Temporary reference anchor UE identifier.

8. The UE of claim 1, wherein the selected reference anchor UE is a first reference anchor UE, and wherein the at least one processor is further configured to cause the UE to: The second reference anchor UE for the Side Link Positioning Protocol (SLPP) session is selected as the first reference anchor UE, based at least in part on one or more of the selection criteria.

9. The UE of claim 8, wherein the at least one processor is further configured to cause the UE to: Perform one or more side link reference signal time difference (SL-RSTD) measurements using the first reference anchor UE and the second reference anchor UE; and The first reference UE and the second reference UE are used to transmit reports of the SL-RSTD measurements, wherein the transmitted reports associate each SL-RSTD measurement with one or more of the first reference anchor UE or the second reference anchor UE.

10. A processor for wireless communication, comprising: At least one memory; and A controller, coupled to and configured to cause the controller to: Use one or more selection criteria to select a reference anchor UE from a set of active anchor UEs; Perform side-link measurements for positioning relative to the selected reference anchor UE; and Transmit one or more of the following: a sidelink measurement report based at least in part on the sidelink measurement performed or information associated with the reference anchor UE.

11. An apparatus for performing network functions, the apparatus comprising: At least one memory; and At least one processor, coupled to and configured to enable the device to: Transmit the initial list of anchor UEs to the target UE; Receive a set of active anchor UEs from the initial anchor UE list from the target UE; Use one or more selection criteria to select a reference anchor UE from the set of active anchor UEs; Location measurement from the target UE receiving side link; and The location of the target UE is calculated using the sidelink positioning measurement.

12. The device of claim 11, wherein the candidate UE list is received from the target UE, and the processor is further configured to generate the initial anchor UE list from the candidate UE list.

13. The device of claim 11, wherein the initial anchor UE list is transmitted in a Side Link Positioning Protocol (SLPP) message.

14. The device of claim 11, wherein the selection criteria are pre-configured in the device.

15. The device of claim 11, wherein the one or more selection criteria include at least one of the following: The threshold value of the side link reference signal received by the target UE; The line-of-sight (LoS) status between the target UE and the corresponding anchor UE; Coverage status; Support for side link time difference of arrival (SL-TDoA) measurement; Whether the position of the corresponding anchor UE in a two-dimensional or three-dimensional location is available; and The Public Land Mobile Network (PLMN) information of the corresponding anchor UE.

16. The device of claim 11, wherein the at least one processor is further configured to cause the device to: Transmit auxiliary information to the selected reference anchor UE.

17. The device of claim 16, wherein the auxiliary information includes at least one of the following: lateral link positioning reference signal (SL-PRS) resource ID, SL-PRS periodicity, comb size, comb size offset, number of symbols, and dedicated SL-PRS and shared resource pool information.

18. The device of claim 16, wherein the location of the target UE is calculated based on a set of SL-RSTD measurements, and each of the SL-RSTD measurements is based on a first time-of-arrival measurement between the target UE and the reference anchor UE and a second time-of-arrival measurement between the target UE and an anchor UE from the set of active anchor UEs.

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