SELECTION OF ANCHOR USER EQUIPMENT FOR POSITIONING - Patent application

Abstract

The anchor UE may be moving or may have a low transmit power, which may affect the accuracy of the target UE's positioning estimate based on the measurements of the PRS associated with the anchor UE. One or more anchor UE candidates may be selected or excluded from being used for positioning based on one or more of the measurement quality measures of the anchor UE candidate's location measurements, the mobility state of the anchor UE candidate, or the GDOP associated with the anchor UE candidate. The mobility state of the anchor UE candidate may be derived from the reported location of the anchor UE candidate or obtained from the anchor UE candidate. The UE selected as the anchor UE is used for the target UE's positioning, and the UEs that qualify as being anchor UEs are excluded from being used for the target UE's positioning.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and benefit of Greek Patent Application No. 20210100220, entitled "ANCHOR USER EQUIPMENT SELECTION FOR POSITIONING," filed March 31, 2021, which is assigned to the assignee of the present application and is expressly incorporated herein by reference in its entirety.

[0002] The subject matter disclosed herein relates to positioning of user equipment using received positioning reference signals, and more particularly to selecting anchor user equipment to be used for positioning. [Background technology]

[0003] The location of a user equipment (UE), such as a mobile phone, can be useful or essential for many applications, including emergency calling, navigation, wayfinding, asset tracking, and Internet services. The location of a UE can be estimated based on information collected from various systems. In cellular networks implemented according to 4G (also called fourth generation) Long Term Evolution (LTE) radio access or 5G (also called fifth generation) “New Radio” (NR), for example, a base station may transmit a downlink reference signal, or a UE may transmit a sidelink reference signal used for positioning, such as a positioning reference signal (PRS). Assistance data is transmitted to the UE to aid in acquiring and measuring signals, and in some implementations, to calculate a position estimate from the measurements. A UE may acquire PRSs transmitted from different base stations or UEs and perform positioning-related measurements, such as reference signal time difference (RSTD), reference signal received power (RSRP), and receive-transmit (RX-TX) time difference measurements, which may be used in various positioning methods, such as time difference of arrival (TDOA), angle of radiation (AoD), and multi-cell round trip time (RTT). The UE may calculate an estimate of its location using various positioning methods or may send the positioning-related measurements to a network entity, such as a location server, which may calculate the UE's location based on the positioning-related measurements. Improved accuracy in positioning is desired. Summary of the Invention [Means for solving the problem]

[0004] An anchor user equipment (UE) as a transmitting / receiving point (TRP) for transmitting and / or receiving a positioning reference signal (PRS) may move or have lower transmit power compared to other UEs, which may affect the accuracy of a target UE's positioning estimate based on measurements of the PRS associated with the anchor UE. One or more anchor UE candidates may be excluded from being used for positioning of one or more other UEs based on one or more of a measurement quality metric of the anchor UE candidate's location measurements, the anchor UE candidate's mobility state, or a geometric dilution of precision (GDOP) associated with the anchor UE candidate. The measurement quality metric may be based on the reference signal time difference (RSTD) or the accuracy of a satellite system or other sensor used to determine the anchor UE candidate's location. The anchor UE candidate's mobility state may be derived from the anchor UE candidate's reported location or obtained from the anchor UE candidate. The anchor UE candidate selected as the anchor UE is used for positioning of the target UE. In some implementations that select one or more anchor UE candidates from a group of anchor UE candidates, the anchor UE candidates may be excluded from the group of anchor UE candidates for the target UE when the group is narrowed down. In this way, the anchor UE candidates are excluded from use as anchor UEs for positioning of the target UE.

[0005] In one implementation, a method for selecting an anchor UE for positioning of a target UE in a wireless network includes obtaining, from one or more of a plurality of anchor UE candidates, one or more location measurement results of the anchor UE candidates and a measurement quality metric for each of the one or more location measurement results; and selecting, based on the one or more measurement quality metrics from the one or more anchor UE candidates, a plurality of anchor UE candidates for positioning of the target UE.

[0006] In one implementation, a device configured to select an anchor UE for positioning of a target UE in a wireless network includes at least one transceiver, at least one memory, and at least one processor coupled to the at least one transceiver and the at least one memory, wherein the at least one processor is configured to cause the device to obtain, from one or more of a plurality of anchor UE candidates via the at least one transceiver, one or more location measurements of the anchor UE candidates and measurement quality measures for each of the one or more location measurements, and to select, via the at least one processor, a plurality of anchor UE candidates for positioning of the target UE based on the one or more measurement quality measures from the one or more anchor UE candidates.

[0007] In one implementation, a non-transitory computer-readable medium includes instructions that, when executed by at least one processor of a device configured to select an anchor UE for positioning of a target user equipment (UE) in a wireless network, cause the device to obtain, from one or more of a plurality of anchor UE candidates via at least one transceiver, one or more location measurement results of the anchor UE candidates and measurement quality measures for each of the one or more location measurement results, and select, via the at least one processor, a plurality of anchor UE candidates for positioning of the target UE based on the one or more measurement quality measures from the one or more anchor UE candidates.

[0008] In one implementation, a device configured to select an anchor UE for positioning of a target UE in a wireless network includes means for obtaining, from one or more of a plurality of anchor UE candidates, one or more location measurement results of the anchor UE candidates and a measurement quality metric for each of the one or more location measurement results, and means for selecting a plurality of anchor UE candidates for positioning of the target UE based on the one or more measurement quality metrics from the one or more anchor UE candidates.

[0009] In one implementation, a method for selecting an anchor UE for positioning [please change "wireless positioning" to "positioning"] of a target UE in a wireless network includes determining, for one or more of a plurality of anchor UE candidates, a mobility state of the anchor UE candidate; and selecting a plurality of anchor UE candidates for positioning of the target UE based on the one or more mobility states.

[0010] In one implementation, a device configured to select an anchor UE for positioning of a target UE in a wireless network includes at least one transceiver, at least one memory, and at least one processor coupled to the at least one transceiver and the at least one memory, wherein the at least one processor is configured to cause the device, via one or more of the at least one transceiver or the at least one processor, to determine, for one or more of a plurality of anchor UE candidates, a mobility state of the anchor UE candidate, and, via the at least one processor, to select, for positioning of the target UE, a plurality of anchor UE candidates based on the one or more mobility states.

[0011] In one implementation, a non-transitory computer-readable medium includes instructions that, when executed by at least one processor of a device configured to select an anchor UE for positioning of a target user equipment (UE) in a wireless network, cause the device, via one or more of the at least one transceiver or the at least one processor, to determine, for one or more of a plurality of anchor UE candidates, a mobility state of the anchor UE candidate, and, via the at least one processor, select, based on the one or more mobility states, a plurality of anchor UE candidates for positioning of the target UE.

[0012] In one implementation, a device configured to select an anchor UE for positioning of a target user equipment (UE) in a wireless network includes means for determining, for one or more of a plurality of anchor UE candidates, a mobility state of the anchor UE candidate, and means for selecting a plurality of anchor UE candidates for positioning of the target UE based on the one or more mobility states.

[0013] In one implementation, a method for selecting an anchor UE for positioning of a target UE in a wireless network includes selecting one or more anchor UEs for positioning of the target UE from a plurality of anchor UE candidates, the selection being based on a plurality of GDOPs, each GDOP being determined by the target UE for a different combination of anchor UE candidates from the plurality of anchor UE candidates.

[0014] In one implementation, a device configured to select an anchor UE for positioning of a target UE in a wireless network includes at least one transceiver, at least one memory, and at least one processor coupled to the at least one transceiver and the at least one memory. The at least one processor is configured to cause the device to select, via one or more of the at least one transceiver or the at least one processor, one or more anchor UEs for positioning of the target UE from a plurality of anchor UE candidates, the selection based on a plurality of GDOPs, each GDOP to be determined by the target UE for a different combination of anchor UE candidates from the plurality of anchor UE candidates.

[0015] In one implementation, a non-transitory computer-readable medium includes instructions that, when executed by at least one processor of a device configured to select an anchor UE for positioning of a target user equipment (UE) in a wireless network, cause the device to select, via one or more of the at least one transceiver or the at least one processor, one or more anchor UEs for positioning of the target UE from a plurality of anchor UE candidates, the selection being based on a plurality of GDOPs, each GDOP being determined by the target UE for a different combination of anchor UE candidates from the plurality of anchor UE candidates.

[0016] In one implementation, a device configured to select an anchor UE for positioning of a target user equipment (UE) in a wireless network includes means for selecting one or more anchor UEs for positioning of the target UE from a plurality of anchor UE candidates, the selection being based on a plurality of GDOPs, each GDOP to be determined by the target UE for a different combination of anchor UE candidates from the plurality of anchor UE candidates.

[0017] Other objects and advantages associated with the embodiments disclosed herein will become apparent to those skilled in the art based on the accompanying drawings and detailed description.

[0018] The accompanying drawings are presented to aid in the explanation of various aspects of the present disclosure and are provided only to illustrate, not limit, the aspects. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 illustrates an exemplary wireless communication system in accordance with various aspects of the present disclosure. [Figure 2] 2 is a block diagram of a design of a base station and a user equipment (UE), which may be one of the base stations and one of the UEs in FIG. 1. [Figure 3] FIG. 1 illustrates a UE capable of supporting positioning services in a wireless network. [Figure 4] FIG. 1 illustrates a base station capable of supporting positioning services in a wireless network. [Figure 5] FIG. 1 illustrates a server capable of supporting positioning services in a wireless network. [Figure 6] 1 illustrates an example technique for determining a location of a mobile device using information obtained from multiple base stations. [Figure 7] 1 is a flowchart of an example method for selecting an anchor UE for positioning of a target UE in a wireless network. [Figure 8] 1 is a flowchart of an example method for selecting an anchor UE for positioning of a target UE in a wireless network. [Figure 9A] FIG. 2 illustrates a first location uncertainty for a UE associated with two transmission / reception points (TRPs) for positioning. [Figure 9B] FIG. 10 illustrates a second location uncertainty for a UE associated with two TRPs for positioning. [Figure 10] 1 is a flowchart of an example method for selecting an anchor UE for positioning of a target UE in a wireless network. [Figure 11] 1 is a flowchart of an example method for selecting an anchor UE for positioning of a target UE in a wireless network. DETAILED DESCRIPTION OF THE INVENTION

[0020] Aspects of the present disclosure are provided in the following description and related drawings, which are directed to various examples provided for illustrative purposes. Alternative aspects may be devised without departing from the scope of the present disclosure. Additionally, well-known elements of the present disclosure will not be described in detail or will be omitted so as not to obscure the relevant details of the present disclosure.

[0021] The words "exemplary" and / or "example" are used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" and / or "example" is not necessarily to be construed as preferred or advantageous over other aspects. Likewise, the term "aspects of the present disclosure" does not require that all aspects of the present disclosure include the discussed feature, advantage or mode of operation.

[0022] Those skilled in the art will understand that the information and signals described below may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the following description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof, depending in part on the particular application, desired design, corresponding technology, etc.

[0023] Further, many aspects are described in terms of sequences of actions to be performed by, for example, elements of a computing device. It will be appreciated that the various actions described herein may be performed by particular circuitry (e.g., an application-specific integrated circuit (ASIC)), by program instructions executed by one or more processors, or by a combination of both. In addition, a sequence of actions described herein may be considered to be embodied entirely in any form of non-transitory computer-readable storage medium storing a corresponding set of computer instructions that, when executed, cause or instruct the associated processor(s) of the device to perform the functions described herein. Accordingly, various aspects of the present disclosure may be embodied in several different forms, all of which are contemplated to be within the scope of the claimed subject matter. Additionally, for each aspect described herein, the corresponding form of any such aspect may be described herein, for example, as “logic configured to” perform the described actions.

[0024] The terms “user equipment (UE)” and “base station,” as used herein, are not intended to be specific to or otherwise limited to any particular radio access technology (RAT) unless otherwise specified. In general, a UE may be any wireless communication device (e.g., a mobile phone, a router, a tablet computer, a laptop computer, a tracking device, a wearable (e.g., a smart watch, glasses, an augmented reality (AR) / virtual reality (VR) headset, etc.), a vehicle (e.g., an automobile, a motorcycle, a bicycle, etc.), an Internet of Things (IoT) device, etc.) used by a user to communicate over a wireless communication network. A UE may be mobile or may be stationary (e.g., at some time) and may communicate with a radio access network (RAN). The term “UE,” as used herein, may be referred to interchangeably as an “access terminal” or “AT,” a “client device,” a “wireless device,” a “subscriber device,” a “subscriber terminal,” a “subscriber station,” a “user terminal” or “UT,” a “mobile terminal,” a “mobile station,” a “mobile device,” or variations thereof. In general, a UE can communicate with a core network via a RAN, through which the UE can be connected to external networks such as the Internet and to other UEs. Of course, other mechanisms for connecting to the core network and / or the Internet are also possible for a UE, such as via a wired access network, a wireless local area network (WLAN) network (e.g., based on the IEEE 802.11 family of standards), etc.

[0025] Depending on the network in which it is deployed, a base station may operate according to one of several RATs in communication with UEs and may alternatively be referred to as an access point (AP), network node, NodeB, evolved NodeB (eNB), New Radio (NR) Node B (also referred to as gNodeB or gNB), etc. Additionally, in some systems, a base station may provide pure edge node signaling functionality, while in other systems, it may provide additional control and / or network management functions. A communication link through which a UE can transmit signals to a base station is referred to as an uplink (UL) channel or reverse link channel (e.g., reverse traffic channel, reverse control channel, access channel, etc.). A communication link through which a base station can transmit signals to a UE is referred to as a downlink (DL) or forward link channel (e.g., paging channel, control channel, broadcast channel, forward traffic channel, etc.). A communication link through which UEs can transmit signals to each other is referred to as a sidelink (SL). As used herein, the term traffic channel (TCH) can refer to either an UL / reverse traffic channel or a DL / forward traffic channel.

[0026] The term "base station" can refer to a single physical transmission-reception point (TRP) or multiple physical TRPs, which may or may not be collocated. For example, when the term "base station" refers to a single physical TRP, the physical TRP may be a base station antenna corresponding to the base station's cell. When the term "base station" refers to multiple co-located physical TRPs, the physical TRPs may be an array of base station antennas (e.g., as in a multiple-input multiple-output (MIMO) system or when the base station utilizes beamforming). When the term "base station" refers to multiple non-co-located physical TRPs, the physical TRPs may be a distributed antenna system (DAS) (a network of spatially separated antennas connected to a common source via a transport medium) or a remote radio head (RRH) (a remote base station connected to a serving base station). In some implementations, a TRP may be a UE.

[0027] To support UE positioning, two broad classifications of positioning strategies have been defined: control plane-based and user plane-based. In the context of control plane (CP) positioning, signaling related to positioning and positioning support may be carried over existing network (and UE) interfaces and using existing protocols dedicated to signaling transport. In the context of user plane (UP) positioning, signaling related to positioning and positioning support may be carried as part of other data using protocols such as Internet Protocol (IP), Transmission Control Protocol (TCP), and User Datagram Protocol (UDP).

[0028] The 3rd Generation Partnership Project (3GPP) defines control plane positioning strategies for UEs using radio access according to Global System for Mobile communications (GSM) (2G), Universal Mobile Telecommunications System (UMTS) (3G), LTE (4G), and New Radio (NR) for fifth generation (5G). These strategies are defined in 3GPP Technical Specifications (TS) 23.271 and 23.273 (common part), 43.059 (GSM access), 25.305 (UMTS access), 36.305 (LTE access), and 38.305 (NR access). For UP positioning, release 16 of the 3GPP standard for NR defines the multicell round trip time (RTT), DL angle of radiation (AOD), and UL angle of arrival (AOA) with respect to zenith and azimuth angles. Release 16 also defines UE-based positioning associated with DL-TDOA and DL-AOD, DL positioning reference signals (PRS) (DL-PRS), and sounding reference signals (SRS) for positioning. Release 16 also defines beam-specific (PRS) operation for mmWave and broadcast of assistance data for positioning. Release 17 of the 3GPP standard for NR may define UE-initiated on-demand transmission of DL-PRS, network-initiated on-demand transmission of DL-PRS, radio resource control (RRC) inactive DL-only, UL-only, or DL+UL-based positioning, access point (AP) DL-PRS transmission, and / or aggregation of DL-PRS across multiple frequencies.The Open Mobile Alliance (OMA) has similarly defined a UP positioning strategy known as Secure User Plane Location (SUPL), which can be used to locate UEs accessing any of several radio interfaces that support IP packet access, such as General Packet Radio Service (GPRS) with GSM, GPRS with UMTS, or IP access with LTE or NR.

[0029] Both CP-based positioning (also called location determination) approaches and UP-based positioning approaches may utilize a location server to support positioning (localization) of the UE. The location server may be part of or accessible from the serving network or home network for the UE, or may simply be accessible via the Internet or via a local intranet. When positioning of the UE is required, the location server may initiate a session (e.g., a location determination session or a SUPL session) with the UE to coordinate position measurements by the UE and determination of the UE's estimated location. During a positioning session, the location server may request positioning capabilities of the UE (or the UE may provide them without a request), provide assistance data to the UE (e.g., if requested by the UE or even without a request), and request position estimates or position measurements from the UE for various positioning techniques, e.g., Global Navigation Satellite System (GNSS), Time Difference of Arrival (TDOA), Angle of Radiation (AoD), Round Trip Time (RTT) or Multi-Cell RTT (Multi-RTT), and / or Enhanced Cell ID (ECID) positioning methods. The assistance data may be used by the UE to acquire and measure GNSS and / or PRS signals (e.g., by providing expected characteristics of these signals, such as frequency, expected time of arrival, signal coding, signal Doppler, etc.).

[0030] In UE-based modes of operation, assistance data may additionally or alternatively be used by the UE to help determine a position estimate from obtained position measurements (e.g., where the assistance data provides satellite ephemeris data in the case of GNSS positioning, or other base station characteristics such as base station position and PRS timing in the case of terrestrial positioning using TDOA, AoD, Multi-RTT, etc.).

[0031] In the UE-assisted mode of operation, the UE may return position measurements to the location server, which may determine an estimated position of the UE based on these measurements and possibly also other known or configured data (e.g., satellite ephemeris data for GNSS positioning, or base station positions and possibly base station characteristics including PRS timing in the case of terrestrial positioning using, e.g., TDOA, AoD, Multi-RTT, etc.).

[0032] In another standalone mode of operation, the UE may perform location-related measurements without using any positioning assistance data from a location server, and may further calculate a position or change in position without using any positioning assistance data from a location server. Positioning methods that may be used in the standalone mode include GPS or other types of GNSS (e.g., where the UE obtains satellite orbit data from data broadcast by the GPS or other GNSS satellites themselves) as well as sensors.

[0033] For 3GPP CP location determination, the location server may be an enhanced serving mobile location center (E-SMLC) for LTE access, a standalone SMLC (SAS) for UMTS access, a serving mobile location center (SMLC) for GSM access, or a Location Management Function (LMF) for 5G NR access. In the case of OMA SUPL location, the location server may be a SUPL Location Platform (SLP), which may operate as either: (i) a home SLP (H-SLP) if it is in or associated with the UE's home network or provides the UE with a permanent subscription for location services; (ii) a discovered SLP (D-SLP) if it is in or associated with some other (non-home) network or is not associated with any network; (iii) an Emergency SLP (E-SLP) if it assists in location for emergency calls initiated by the UE; or (iv) a visited SLP (V-SLP) if it is in or associated with the serving network or current local area for the UE.

[0034] During a positioning session, the location server and the UE may exchange messages defined according to several positioning protocols to coordinate the determination of an estimated position. Possible positioning protocols may include, for example, the LTE Positioning Protocol (LPP) defined by 3GPP in 3GPP TS 36.355 and the LPP Extensions (LPPe) protocol defined by OMA in OMA TSs OMA-TS-LPPe-V1_0, OMA-TS-LPPe-V1_1, and OMA-TS-LPPe-V2_0. The LPP and LPPe protocols may be used in combination such that an LPP message contains one embedded LPPe message. The combined LPP and LPPe protocols may be referred to as LPP / LPPe. LPP and LPP / LPPe may also be used to help support 3GPP control plane strategies for LTE or NR access, where LPP or LPP / LPPe messages are exchanged between the UE and the E-SMLC or between the UE and the LMF. LPP or LPPe messages may be exchanged between the UE and the E-SMLC via the serving mobility management entity (MME) and serving eNodeB for the UE. LPP or LPPe messages may also be exchanged between the UE and the LMF via the serving access and mobility management entity (AMF) and serving NR Node B (gNB) for the UE. LPP and LPP / LPPe may also be used to help support the OMA SUPL approach for many types of wireless access (such as LTE, NR, and WiFi) that support IP messaging. In this case, LPP or LPP / LPPe messages may be exchanged between a SUPL Enabled Terminal (SET), the term used for the UE for SUPL, and an SLP, and may be transported within a SUPL message, such as a SUPL POS or SUPL POS INIT message.

[0035] A location server and a base station (e.g., an eNodeB for LTE access) may exchange messages to enable the location server to (i) obtain location measurements of a particular UE from the base station, or (ii) obtain location information from the base station that is not associated with a particular UE, such as antenna position coordinates for the base station, cells supported by the base station (e.g., cell identification information), cell timing for the base station, and / or parameters for signals transmitted by the base station, such as PRS signals. For LTE access, the LPP A (LPPa) protocol may be used to transfer such messages between a base station that is an eNodeB (eNB) and a location server that is an E-SMLC. For NR access, the NRPPA protocol may be used to transfer such messages between a base station that is a gNodeB (gNB) and a location server that is an LMF. Note that the terms “parameter” and “information element” (IE) are synonymous and are used interchangeably herein.

[0036] During positioning using signaling in LTE and 5G NR, the UE typically acquires dedicated positioning signals, e.g., PRSs, transmitted by base stations, which are used to generate desired measurements for supported positioning techniques. Positioning reference signals (PRSs) are defined for 5G NR positioning to enable the UE to detect and measure closer base stations or transmission / reception points (TRPs). Downlink (DL) PRSs are transmitted from a reference base station and one or more neighboring base stations. Based on the time of arrival (TOA) of the PRSs from the reference base station and neighboring base stations, the UE may generate a DL reference signal time difference (RSTD) for DL ​​TDOA positioning, sometimes referred to as an observed time difference of arrival (OTDOA). In a similar process, the UE may transmit uplink reference signals for positioning, sometimes referred to as a sounding reference signal (SRS) for positioning, to the reference base station and neighboring base stations. The TOA of the SRSs at the reference and neighboring stations may be used to generate an UL RSTD for UL TDOA positioning, sometimes referred to as an uplink time difference of arrival (UTDOA).

[0037] As described above, a base station may be a transmitting / receiving point (TRP) to be used for UE positioning. In some scenarios, it may be advantageous for one or more TRPs to be UEs (which may move within the network) compared to base stations that typically do not move. For example, a base station may provide a PRS over an UP interface (referred to as a Uu interface, such as LTE-Uu or NR-Uu). In a first scenario, a target UE for positioning is within range of the Uu interface for DL ​​and within range of the Uu interface for UL to at least one anchor base station. The UE may be used as a TRP to assist in positioning (which may be referred to as an anchor for positioning). In this way, the anchor UE may transmit and receive a PRS over SL with the target UE. Additional anchors (such as additional anchor UEs or additional base stations) may be used to increase the number of TRPs to a sufficient number for positioning (e.g., two or three TRPs) or to improve the accuracy of location estimation. In a second scenario, the target UE is not within range of the Uu interface for DL ​​or UL of any base station. An anchor UE may be used to perform SL-only positioning. For example, a low-power device (such as a wearable) may be within range of multiple UEs but not within range of a base station. The UE may be used to perform SL-only positioning of the wearable. In a third scenario, a target UE is within range of the base station's Uu interface for DL ​​but not within range of the Uu interface for UL. An anchor UE may be used to assist with the UL portion (such as relaying information back to the base station or location server). For example, a target UE with limited transmit capabilities (such as a wearable device or other low-power device) may be able to receive on the DL from the base station but not be able to transmit on the UL to the base station.

[0038] Support for SL-only positioning and / or SL-assisted positioning is desirable. Because UEs may move within a wireless network or may have lower transmit power than other UEs, some anchor UE candidates may be better anchor UEs than other anchor UE candidates. As described herein, anchor UEs may be determined or excluded for one or more target UEs. The selection of one or more anchor UE candidates may be based on one or more measurement quality measures (such as a received signal (RS) received power (RSRP) measure or a signal-to-noise ratio (SNR) measure for positioning, the accuracy of the anchor UE candidate's location measurement results), the mobility state of the anchor UE candidate, or a geometric dilution of precision (GDOP) associated with the anchor UE candidate. For example, a subset of one or more anchor UE candidates may be selected from multiple anchor UE candidates as potential anchors for one or more target UEs. As used herein, selecting one or more anchor UE candidates may refer to narrowing down multiple anchor UE candidates to exclude one or more anchor UE candidates from being chosen as anchors for one or more target UEs. In this manner, selecting may refer to selecting an anchor UE candidate as an anchor, excluding an anchor UE candidate from being selected as an anchor, selecting a subset of anchor UE candidates from a group of anchor UE candidates, or narrowing down a group of anchor UE candidates to exclude one or more anchor UE candidates from consideration as an anchor. Narrowing down anchor UE candidates may be used herein to refer to excluding anchor UE candidates from consideration as an anchor. In one implementation, a device obtains one or more location measurements of the anchor UE candidates and a measurement quality metric for each of the one or more location measurements from one or more of the multiple anchor UE candidates. The device also selects multiple anchor UE candidates for positioning of the target UE based on the one or more measurement quality metrics from the one or more anchor UE candidates.In another implementation, the device determines, for one or more of the multiple anchor UE candidates, a mobility state of the anchor UE candidate. The device also selects multiple anchor UE candidates for positioning of the target UE based on the one or more mobility states. In another implementation, the device selects one or more anchor UEs for positioning of the target UE from the multiple anchor UE candidates, the selection being based on multiple GDOPs, each GDOP determined by the target UE for a different combination of anchor UE candidates from the multiple anchor UE candidates. Selecting or excluding anchor UEs may be performed by the UE or a location server of the wireless network. As used herein, determining a GDOP may refer to estimating or calculating a GDOP in any appropriate manner. Although some examples describe determining a GDOP by the target UE, the GDOP may be determined (e.g., estimated or calculated) by a location server, a base station, or another appropriate wireless network entity (e.g., for UE-assisted positioning of the target UE).

[0039] 1 illustrates an exemplary wireless communication system 100. The wireless communication system 100 (which may also be referred to as a wireless wide area network (WWAN) or a wireless network (e.g., a cellular network)) may include various base stations 102 and various UEs 104, where one or more of the base stations 102 and / or UEs 104 may be referred to herein as TRPs 102 or 104. The base stations 102 may include macrocell base stations (high-power cellular base stations) and / or small cell base stations (low-power cellular base stations). In an aspect, the macrocell base stations may include eNBs, if the wireless communication system 100 corresponds to an LTE network, or gNBs, if the wireless communication system 100 corresponds to a 5G network, or a combination of both, and the small cell base stations may include femtocells, picocells, microcells, etc.

[0040] The base stations 102 may collectively form a RAN and may interface with a core network 170 (e.g., Evolved Packet Core (EPC) or Next Generation Core (NGC)) through backhaul links 122, and through the core network 170, with a location server 172, which may include one or more location servers. In addition to other functions, the base stations 102 may perform functions related to one or more of: forwarding user data, encryption and decryption of radio channels, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, non-access stratum (NAS) message delivery, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast services (MBMS), subscriber and equipment tracking, RAN information management (RIM), paging, positioning, and alert message delivery. The base stations 102 may communicate with each other directly or indirectly (e.g., through EPC / NGC) via backhaul links 134, which may be wired or wireless.

[0041] The base stations 102 may communicate wirelessly with the UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. In an aspect, one or more cells may be supported by the base station 102 in each coverage area 110. A “cell” is a logical communication entity used for communication with a base station (e.g., over some frequency resources referred to as a carrier frequency, component carrier, carrier, band, etc.) and may be associated with an identifier (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID)) to distinguish between cells operating over the same or different carrier frequencies. In some cases, different cells may be configured according to different protocol types (e.g., machine type communication (MTC), narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB), or others) that may provide access for different types of UEs. In some cases, the term “cell” may also refer to a geographic coverage area (e.g., a sector) of a base station, as long as the carrier frequency can be detected and used for communication within some portions of the geographic coverage area 110.

[0042] The geographic coverage areas 110 of neighboring macrocell base stations 102 may partially overlap (e.g., in handover regions), but some of the geographic coverage areas 110 may significantly overlap with larger geographic coverage areas 110. For example, a small cell base station 102' may have a coverage area 110' that significantly overlaps with the coverage area 110 of one or more macrocell base stations 102. A network that includes both small cell base stations and macrocell base stations may be known as a heterogeneous network. A heterogeneous network may also include Home eNBs (HeNBs), which may serve closed groups known as Closed Subscriber Groups (CSGs).

[0043] The communication link 120 between the base station 102 and the UE 104 may include UL (also called reverse link) transmissions from the UE 104 to the base station 102, and / or downlink (DL) (also called forward link) transmissions from the base station 102 to the UE 104. The communication link 120 may use MIMO antenna techniques, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link 120 may be over one or more carrier frequencies. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL ​​than UL).

[0044] The wireless communication system 100 may further include a wireless local area network (WLAN) access point (AP) 150 communicating with a WLAN station (STA) 152 via a communication link 154 in an unlicensed frequency spectrum (e.g., 5 GHz). When communicating in the unlicensed frequency spectrum, the WLAN STA 152 and / or the WLAN AP 150 may perform clear channel assessment (CCA) before communicating to determine whether a channel is available.

[0045] The small cell base station 102' may operate in a licensed and / or unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell base station 102' may employ LTE or 5G technology and use the same 5 GHz unlicensed frequency spectrum used by the WLAN AP 150. A small cell base station 102' employing LTE / 5G in an unlicensed frequency spectrum may extend coverage to and / or increase capacity of the access network. LTE in the unlicensed spectrum is sometimes referred to as LTE-unlicensed (LTE-U), licensed assisted access (LAA), or MultiFire.

[0046] The wireless communication system 100 may further include a millimeter-wave (mmW) base station 180 that may operate within mmW and / or quasi-mmW frequencies in communication with the UE 182. Extremely high frequency (EHF) is the RF portion of the electromagnetic spectrum. EHF ranges from 30 GHz to 300 GHz and has a wavelength between 1 millimeter and 10 millimeters. Radio waves in this band are sometimes referred to as millimeter waves. Sub-mmW can extend down to frequencies of 3 GHz, where the wavelength is 100 millimeters. The very high frequency (SHF) band, also known as centimeter wave, extends between 3 GHz and 30 GHz. Communications using the mmW / quasi-mmW radio frequency bands have high path loss and relatively short distances. The mmW base station 180 and the UE 182 may utilize beamforming (transmit and / or receive) over the mmW communication link 184 to compensate for the significant path loss and short distances. It will be understood that in alternative configurations, one or more base stations 102 may also transmit using mmW or quasi-mmW and beamforming. Therefore, it will be understood that the above exemplification is merely illustrative and should not be construed as limiting the various aspects disclosed herein.

[0047] Transmit beamforming is a technique for focusing an RF signal in a specific direction. Traditionally, when a network node (e.g., a base station) broadcasts an RF signal, it broadcasts that signal in all directions (omnidirectionally). With transmit beamforming, the network node determines where a given target device (e.g., a UE) is located (relative to the transmitting network node) and emits a stronger downlink RF signal in that specific direction, thereby providing a stronger RF signal at a faster speed (in terms of data rate) to the receiving device. To change the directionality of the RF signal when transmitting, the network node can control the phase and relative amplitude of the RF signal at each of one or more transmitters broadcasting the RF signal. For example, the network node may use an array of antennas (also called a "phased array" or "antenna array") that creates beams of RF waves that can be "steered" to point in different directions without actually moving the antennas. Specifically, RF currents from the transmitters are supplied to individual antennas with the correct phase relationship so that the radio waves from the separate antennas combine together to increase radiation in desired directions while canceling to suppress radiation in undesired directions.

[0048] In receive beamforming, a receiver uses a receive beam to amplify RF signals detected on a given channel. For example, the receiver can increase the gain setting and / or adjust the phase setting of an array of antennas in a particular direction to amplify (e.g., increase the gain level of) RF signals received from that direction. Thus, when a receiver is said to beamform in a certain direction, it means that the beam gain in that direction is higher than the beam gain along other directions, or that the beam gain in that direction is highest compared to the beam gain in that direction of all other receive beams available to the receiver. This results in a stronger received signal strength (e.g., reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-interference-plus-noise ratio (SINR), signal-to-noise ratio (SNR), etc.) of RF signals received from that direction.

[0049] In 5G, the frequency spectrum in which wireless nodes (e.g., base station 102 / 180, UE 104 / 182) operate is divided into multiple frequency ranges: FR1 (450 MHz to 6000 MHz), FR2 (24250 MHz to 52600 MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). In a multi-carrier system such as 5G, one of the carrier frequencies is called the “primary carrier” or “anchor carrier” or “primary serving cell” or “PCell,” and the remaining carrier frequencies are called “secondary carriers” or “secondary serving cells” or “SCells.” In carrier aggregation, the anchor carrier is the carrier operating on the primary frequency (e.g., FR1) utilized by the UE 104 / 182 and on the cell in which the UE 104 / 182 either performs an initial radio resource control (RRC) connection establishment procedure or initiates an RRC connection re-establishment procedure. The primary carrier carries all common control channels and UE-specific control channels. The secondary carrier is a carrier operating on a second frequency (e.g., FR2) that can be configured once an RRC connection is established between the UE 104 and the anchor carrier and can be used to provide additional radio resources. Because both the primary uplink carrier and the primary downlink carrier are typically UE-specific, the secondary carrier may contain only necessary signaling information and signals; for example, UE-specific signaling information and signals may not be present in the secondary carrier. This means that different UEs 104 / 182 in a cell may have different downlink primary carriers. The same applies to the uplink primary carrier. The network can change the primary carrier of any UE 104 / 182 at any time. This is done, for example, to balance the load on different carriers.Since a "serving cell" (whether a PCell or an SCell) corresponds to the carrier frequency / component carrier over which some base station is communicating, terms such as "cell," "serving cell," "component carrier," and "carrier frequency" may be used interchangeably.

[0050] For example, still referring to FIG. 1, one of the frequencies utilized by the macrocell base station 102 may be an anchor carrier (or “PCell”), and other frequencies utilized by the macrocell base station 102 and / or the mmW base station 180 may be secondary carriers (“SCells”). Simultaneous transmission and / or reception of multiple carriers allows the UE 104 / 182 to significantly increase its data transmission and / or reception rates. For example, two aggregated 20 MHz carriers in a multi-carrier system theoretically double the data rate (i.e., 40 MHz) compared to that achieved by a single 20 MHz carrier.

[0051] The wireless communication system 100 may further include one or more UEs, such as a UE 190, that indirectly connect to one or more communication networks via one or more sidelinks (SLs), such as device-to-device (D2D) peer-to-peer (P2P) links. In the example of FIG. 1, the UE 190 has a D2D P2P link 192 in which one of the UEs 104 is connected to one of the base stations 102 (e.g., through which the UE 190 may indirectly obtain cellular connectivity) and a D2D P2P link 194 in which the WLAN STA 152 is connected to the WLAN AP 150 (through which the UE 190 may indirectly obtain WLAN-based Internet connectivity). In an example, the D2D P2P links 192 and 194 may be supported using any well-known D2D RAT, such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), Bluetooth, etc. In this example, the UE 190 may be a relay UE between the UE 152 and the base station 102. One or more UEs may be relay UEs between the device and the base station.

[0052] Wireless communications system 100 may further include a UE 164, which may communicate with macrocell base station 102 via communications link 120 and / or with mmW base station 180 via mmW communications link 184. For example, macrocell base station 102 may support a PCell and one or more SCells for UE 164, and mmW base station 180 may support one or more SCells for UE 164.

[0053] A target UE 104 for positioning may be within wireless range of one or more base stations 102 (which may be TRPs 102 for positioning of the target UE 104). Additionally or alternatively, the target UE 104 may be within wireless range of one or more other UEs 104 (which may be anchor UEs as TRPs 104 for positioning of the target UE 104). For example, the target UE 104 may be within range of at least two or three devices capable of operating as TRPs. The anchor base station may transmit a PRS on the DL (DL-PRS) to one or more target UEs, and the anchor UE may transmit a PRS on the SL (SL-PRS) to one or more target UEs.

[0054] 2 shows a block diagram of a design 200 of a base station 102 and a UE 104, which may be one of the base stations and one of the UEs in FIG. 1. Base station 102 may be equipped with T antennas 234a through 234t, and UE 104 may be equipped with R antennas 252a through 252r, where in general T≧1 and R≧1.

[0055] At the base station 102, the transmit processor 220 may receive data for one or more UEs from a data source 212, select one or more modulation and coding schemes (MCSs) for each UE based at least in part on a channel quality indicator (CQI) received from the UE, process (e.g., encode and modulate) the data for each UE based at least in part on the MCS selected for the UE, and provide data symbols to all UEs. The transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI), etc.) and control information (e.g., CQI requests, grants, upper layer signaling, etc.) and provide overhead symbols and control symbols. The transmit processor 220 may also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRSs)) and synchronization signals (e.g., primary synchronization signals (PSSs) and secondary synchronization signals (SSSs)). The transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on ​​the data symbols, control symbols, overhead symbols, and / or reference symbols, if applicable, and may provide T output symbol streams to T modulators (MODs) 232a through 232t. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. The T downlink signals from modulators 232a through 232t may be transmitted via T antennas 234a through 234t, respectively. According to various aspects described in more detail below, synchronization signals may be generated using position coding to convey additional information.

[0056] At the UE 104, antennas 252a through 252r may receive downlink signals from the base station 102 and / or other base stations and may provide received signals to demodulators (DEMODs) 254a through 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) its received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all R demodulators 254a through 254r, perform MIMO detection on the received symbols, if applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate and decode) the detected symbols and provide decoded data for the UE 104 to a data sink 260 and decoded control information and system information to the controller / processor 280. The channel processor may determine a reference signal received power (RSRP), a received signal strength indicator (RSSI), a reference signal received quality (RSRQ), a channel quality indicator (CQI), etc. In some aspects, one or more components of the UE 104 may be included in a housing.

[0057] On the uplink, at the UE 104, a transmit processor 264 may receive and process data from a data source 262 and control information (e.g., for reports comprising RSRP, RSSI, RSRQ, CQI, etc.) from a controller / processor 280. The transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by modulators 254a through 254r (e.g., for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to the base station 102. At the base station 102, uplink signals from the UE 104 and other UEs may be received by antennas 234, processed by a demodulator, detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information transmitted by the UE 104. The receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to a controller / processor 240. The base station 102 may include a communication unit 244 and may communicate with a network controller 289 via the communication unit 244. The network controller 289 may include a communication unit 294, a controller / processor 290, and a memory 292.

[0058] The controller / processor 240 of the base station 102, the controller / processor 280 of the UE 104, the controller 290 of the network controller 289, which may be the location server 172, and / or any other component of FIG. 2 may perform one or more techniques related to supporting positioning services for UEs, as described in more detail elsewhere herein. For example, the controller / processor 240 of the base station 102, the controller 290 of the network controller 289, the controller / processor 280 of the UE 104, and / or any other component of FIG. 2 may perform or direct operations for the processes illustrated in the figures and described herein, for example. The memories 242, 282, and 292 may store data and program codes for the base station 102, the UE 104, and the network controller 289, respectively. In some aspects, the memory 242 and / or the memory 282 and / or the memory 292 may comprise a non-transitory computer-readable medium that stores one or more instructions for wireless communication. For example, the one or more instructions, when executed by one or more processors of the base station 102, the network controller 289, and / or the UE 104, may perform or direct the operations of the processes described herein. The scheduler 246 may schedule UEs for data transmission on the downlink and / or uplink.

[0059] The location server 172 (which may include the network controller 289) may be configured to refine or select TRPs (including one or more anchor UEs) for positioning, determine and indicate resources (such as specific PRS resources or PRS formats) to be used for positioning, determine the location of one or more UEs in the wireless network, store positioning information for one or more UEs, or perform other operations related to positioning one or more UEs in the wireless network. The positioning information may be used for various operations, such as cell selection, handover, beamforming, or position determination, or other aspects of the wireless network 100.

[0060] As noted above, FIG. 2 is provided as an example. Other examples may differ from those described with respect to FIG. 2. For example, while FIG. 2 illustrates communication between a base station 102 and a UE 104, communication may occur between two UEs 104 via a sidelink. In this manner, the design of the UE 104 shown in FIG. 2 and another design of the UE 104 may communicate with each other via a sidelink. The UE in this example may be a target UE, a candidate anchor UE, or an anchor UE for positioning (e.g., a UE selected to be a TRP).

[0061] A base station or UE may broadcast, unicast, or groupcast one or more PRSs in a wireless network (such as in a cellular network including LTE and / or 5G technologies). In the frequency domain, the available bandwidth may be divided into evenly spaced orthogonal subcarriers (also called "tones" or "bins"). For example, for a regular length cyclic prefix (CP) using 15 kHz spacing, the subcarriers may be grouped into groups of 12 subcarriers. A resource of one OFDM symbol length in the time domain and one subcarrier in the frequency domain may be referred to as a resource element (RE). In this example, each grouping of 12 subcarriers and 14 OFDM symbols is called a resource block (RB), and in the above example, the number of subcarriers in a resource block is

[0062]

number

[0063] For a given channel bandwidth, the number of available resource blocks on each channel, also called the transmission bandwidth configuration, can be written as:

[0064]

number

[0065] For example, for the 3 MHz channel bandwidth in the example above, the number of available resource blocks on each channel is

[0066]

number

[0067] It should be noted that the frequency components of a resource block (e.g., 12 subcarriers) are called a physical resource block (PRB).

[0068] The base station may transmit radio frames, or other physical layer signaling sequences, supporting PRS signals (i.e., downlink (DL) PRS) according to a frame structure similar to the example above, which may be measured and used for location estimation of the target UE. The UE may transmit radio frames, or other physical layer signaling sequences, supporting PRS signals (i.e., sidelink (SL) PRS) according to a frame structure similar to or different from the example above, which may also be measured and used for location estimation of the target UE. Other types of wireless nodes in a wireless network (e.g., distributed antenna systems (DAS), remote radio heads (RRHs), APs, etc.) may also be configured to transmit PRSs configured in a manner similar (or the same) as that described above.

[0069] A collection of resource elements used for transmitting PRS signals is called a "PRS resource." A collection of resource elements may span multiple PRBs in the frequency domain and N (e.g., one or more) consecutive symbols within a slot in the time domain. A "PRS resource set" is a set of PRS resources used for transmitting PRS signals, and each PRS resource has a PRS resource identifier (ID). In addition, PRS resources in a PRS resource set are associated with the same TRP. A PRS resource ID in a PRS resource set is associated with a single beam transmitted from a single TRP (a TRP may transmit one or more beams). Note that this does not imply that the TRPs and beams from which signals are transmitted are known to the UE.

[0070] The PRS may be transmitted in special positioning subframes that are grouped into positioning occasions. A PRS occasion is one instance of a regularly repeating time window (e.g., consecutive slots) in which a PRS is expected to be transmitted. Each regularly repeating time window may include a group of one or more consecutive PRS opportunities. Each PRS opportunity may be N PRS A PRS positioning occasion may include consecutive positioning subframes. PRS positioning occasions for a cell supported by a base station or UE may occur periodically at intervals. Multiple PRS opportunities may be associated with the same PRS resource configuration, in which case each such opportunity may be referred to as a "PRS resource opportunity," etc.

[0071] The PRS may be transmitted at a constant power. The PRS may also be transmitted at zero power (i.e., muted). Muting, which turns off regularly scheduled PRS transmissions, may be useful when PRS signals between different cells overlap by occurring simultaneously or nearly simultaneously. In this case, PRS signals from some cells may be muted, while PRS signals from other cells are transmitted (e.g., at a constant power). Muting may aid UE signal acquisition and time of arrival (TOA) and reference signal time difference (RSTD) measurements of unmuted PRS signals (by eliminating interference from muted PRS signals). Muting may be viewed as not transmitting a PRS for a given positioning occasion for a particular cell. A muting pattern (also referred to as a muting sequence) may be signaled to the UE (e.g., using the LTE Positioning Protocol (LPP)) using a bit string. For example, if a bit at location j is set to “0” in a bit string signaled to indicate the muting pattern, the UE may infer that the PRS will be muted for the jth positioning occasion.

[0072] To further enhance the audibility of the PRS, the positioning subframe may be a low-interference subframe transmitted without a user data channel. As a result, in an ideally synchronized network, the PRS may be interfered with by PRSs of other cells with the same PRS pattern index (i.e., the same frequency shift), but not by data transmissions. The frequency shift may be different depending on the PRS ID (

[0073]

number

[0074] ) or, if no PRS ID is assigned, the Physical Cell Identifier (PCI) (

[0075]

number

[0076] ), which results in an effective frequency reuse factor of 6.

[0077] Also to enhance PRS audibility (e.g., when the PRS bandwidth is limited, such as when there are only six resource blocks corresponding to a 1.4 MHz bandwidth), the frequency band for successive PRS positioning occasions (or successive PRS subframes) may be changed in a known and predictable manner via frequency hopping. Additionally, a cell supported by a base station or UE may support more than one PRS configuration, where each PRS configuration may have a different frequency offset (vshift), a different carrier frequency, a different bandwidth, a different code sequence, and / or a certain number of subframes (N) per positioning occasion. PRS ) and a specific period (T PRSIn some implementations, one or more of the PRS configurations supported in a cell may be for directional PRS and thus may have additional distinct characteristics, such as distinct directions of transmission, distinct horizontal angular ranges, and / or distinct vertical angular ranges.

[0078] The PRS configuration, including the PRS transmission / muting schedule as described above, is signaled to the UE to enable the UE to perform PRS positioning-related measurements. In this manner, the UE may not be expected to blindly perform PRS configuration detection.

[0079] Similar to the DL PRS transmitted by the base station discussed above, the target UE may transmit an UL PRS for positioning and / or an SL PRS for positioning. The UL PRS may be, for example, a Sounding Reference Signal (SRS) for positioning. The SL PRS may be an SRS-like signal.

[0080] Using the received DL PRS from the base station or the SL PRS from the anchor UE and / or the UL PRS transmitted to the base station or the SL PRS to the anchor UE, the target UE, the anchor UE, the base station (e.g., a gNB), or other devices of the wireless network may perform various positioning-related measurements (also referred to as location measurements). Other measures that may be determined include one or more of a measurement quality measure (which may indicate the quality of the UE's positioning-related measurements or signal quality, such as an RSRP measure or an SNR measure), the mobility state of the anchor UE, or a GDOP associated with the TRP.

[0081] 3 illustrates a UE 300 capable of positioning services in a wireless network such as wireless network 100, which is an example of a UE 104. The UE 300 includes a computing platform including at least one processor 310, a memory 311 including software (SW) 312, one or more sensors 313, a transceiver interface 314 for a transceiver 315, a user interface 316, a satellite positioning system (SPS) receiver 317, a camera 318, and a location device (PD) 319. The processor 310, memory 311, sensors 313, transceiver interface 314, user interface 316, SPS receiver 317, camera 318, and location device 319 may be communicatively coupled to one another by a bus 320 (e.g., which may be configured for optical and / or electrical communication). One or more of the depicted devices (e.g., camera 318, SPS receiver 317, and / or one or more of sensors 313) may be omitted from UE 300. Processor 310 may include one or more intelligent hardware devices, e.g., a central processing unit (CPU), a microcontroller, an application specific integrated circuit (ASIC), etc. Processor 310 may comprise multiple processors, including application processor 330, digital signal processor (DSP) 331, modem processor 332, video processor 333, and / or sensor processor 334. One or more of processors 330-334 may comprise multiple devices (e.g., multiple processors). For example, sensor processor 334 may comprise a processor for, e.g., radar, ultrasound, and / or lidar, etc. Modem processor 332 may support dual SIM / dual connectivity (or even more SIMs). For example, a SIM (Subscriber Identity Module or Subscriber Identity Module) may be used by an original equipment manufacturer (OEM) and another SIM may be used by an end user of the UE 300 for connectivity.Memory 311 is a non-transitory storage medium that may include random access memory (RAM), flash memory, disk memory, and / or read-only memory (ROM), etc. Memory 311 stores software 312, which may be processor-readable, processor-executable software code including instructions that, when executed, are configured to cause processor 310 to operate as a special-purpose computer programmed to perform various functions described herein. Alternatively, software 312 may not be directly executable by processor 310, but may be configured, for example, when compiled and executed, to cause processor 310 to operate as a special-purpose computer to perform various functions described herein. While the description may refer only to processor 310 performing a function, this includes other implementations, such as processor 310 executing software and / or firmware. The description may refer to processor 310 performing a function as shorthand for one or more of processors 330-334 performing the function. The description may refer to the UE 300 performing a function as shorthand for one or more appropriate components of the UE 300 performing the function. The processor 310 may include memory with stored instructions in addition to and / or instead of the memory 311.

[0082] 3 is an example of the present disclosure, including the claims, and is not limiting, and other configurations may be used. For example, an exemplary configuration of a UE includes one or more of processors 330-334 of processor 310, memory 311, and wireless transceiver 340. Other exemplary configurations include one or more of processors 330-334 of processor 310, memory 311, wireless transceiver 340, one or more of sensors 313, user interface 316, SPS receiver 317, camera 318, PD 319, and / or wired transceiver 350.

[0083] The UE 300 may include a modem processor 332 that may be capable of performing baseband processing of signals received and downconverted by the transceiver 315 and / or SPS receiver 317. The modem processor 332 may perform baseband processing of signals to be upconverted for transmission by the transceiver 315. Additionally or alternatively, the baseband processing may be performed by the processor 330 and / or the DSP 331. However, other configurations may be used to perform the baseband processing.

[0084] The UE 300 may include sensors 313, which may include one or more of various types of sensors, such as, for example, one or more inertial sensors, one or more barometric pressure sensors, one or more magnetometers, one or more environmental sensors, one or more light sensors, one or more weight sensors, and / or one or more radio frequency (RF) sensors. An inertial measurement unit (IMU) may comprise, for example, one or more accelerometers (e.g., collectively corresponding to acceleration of the UE 300 in three dimensions) and / or one or more gyroscopes capable of detecting movement, including rotation, of the UE 300. The sensors 313 may include one or more magnetometers for determining orientation (e.g., relative to magnetic north and / or true north), which may be used for any of a variety of purposes, for example, to support one or more compass applications. The environmental sensors may comprise, for example, one or more temperature sensors, one or more barometric pressure sensors, one or more ambient light sensors, one or more camera imagers, and / or one or more microphones, etc. The sensors 313 may generate analog and / or digital signals, the indications of which may be stored in memory 311 and processed by DSP 331 and / or processor 330 to support one or more applications, such as, for example, applications directed to positioning and / or navigation operations.

[0085] The sensors 313 may be used in relative position measurement, relative position determination, motion determination, etc. Information detected by the sensors 313 may be used for motion detection, relative displacement, autonomous navigation, sensor-based position determination, and / or sensor-assisted position determination. The sensors 313 may be useful in determining whether the UE 300 is fixed (stationary) or moving, including rotating, and / or whether to report any useful information regarding the mobility of the UE 300. For example, based on information acquired / measured by the sensors, the UE 300 may notify / report that the UE 300 has detected motion or that the UE 300 has moved, and may report a relative displacement / distance (e.g., via autonomous navigation, or sensor-based position determination, or sensor-assisted position determination enabled by the sensors 313). In another example, the sensors / IMUs may be used to determine the angle and / or orientation of another device relative to the UE 300 for relative positioning information, such as the angle and / or orientation of another device relative to the UE 300.

[0086] The IMU may be configured to provide measurements of the direction and / or rate of movement of the UE 300, which may be used in relative position determination. For example, one or more accelerometers and / or one or more gyroscopes of the IMU may detect the linear acceleration and rotational rate of the UE 300, respectively. The linear acceleration and rotational rate measurements of the UE 300 may be integrated over time to determine the instantaneous direction and displacement of the UE 300's movement. The instantaneous direction and displacement of the movement may be integrated to track the UE 300's position. For example, a reference position of the UE 300 may be determined for a certain instant using, for example, the SPS receiver 317 (and / or by some other means), and measurements from the accelerometers and gyroscopes obtained after this instant may be used in autonomous navigation to determine the UE 300's current position based on the UE 300's movement (direction and distance) compared to the reference position.

[0087] The magnetometer may determine magnetic field strength in different directions, which may be used to determine the orientation of the UE 300. For example, the orientation may be used to provide a digital compass for the UE 300. The magnetometer may be a two-dimensional magnetometer configured to detect and provide an indication of magnetic field strength in two orthogonal dimensions. Alternatively, the magnetometer may be a three-dimensional magnetometer configured to detect and provide an indication of magnetic field strength in three orthogonal dimensions. The magnetometer may provide a means for sensing the magnetic field and providing an indication of the magnetic field, for example, to the processor 310.

[0088] The barometric pressure sensor may determine atmospheric pressure, which may be used to determine the altitude of the UE 300 or the current floor in a building. For example, differential barometric pressure measurements may be used to detect when the floor the UE 300 is on changes, as well as the number of floors that have changed. The barometric pressure sensor may provide a means for sensing barometric pressure and providing an indication of barometric pressure, for example, to the processor 310.

[0089] The transceiver 315 may include one or both of a wireless transceiver 340 or a wired transceiver 350 configured to communicate with other devices over wireless and wired connections, respectively. For example, the wireless transceiver 340 may include a transmitter 342 and a receiver 344 coupled to one or more antennas 346 for transmitting (e.g., on one or more uplink channels and / or one or more sidelink channels) and / or receiving (e.g., on one or more downlink channels and / or one or more sidelink channels) wireless signals 348. In some implementations, the wireless signals 348 may be converted to and from wired (e.g., electrical and / or optical) signals, and wired signals may be converted to the wireless signals 348. Thus, the transmitter 342 may include multiple transmitters, which may be separate components or combined / integrated components, and / or the receiver 344 may include multiple receivers, which may be separate components or combined / integrated components. The wireless transceiver 340 may be configured to communicate signals (e.g., with the TRP and / or one or more other devices) in accordance with various radio access technologies (RATs), such as 5G New Radio (NR), Global System for Mobiles (GSM), Universal Mobile Telecommunications System (UMTS), Advanced Mobile Phone System (AMPS), Code Division Multiple Access (CDMA), Wideband CDMA (WCDMA), Long-Term Evolution (LTE), LTE Direct (LTE-D), 6GPP LTE-V2X (PC5), IEEE 802.11 (including IEEE 802.11p), WiFi, WiFi Direct (WiFi-D), Bluetooth, Zigbee, etc. New Radio may use mm-wave and / or sub-6 GHz frequencies.If the UE 300 is to include a wired transceiver, the wired transceiver 350 may include a transmitter 352 and a receiver 354 configured for wired communication. The transmitter 352 may include multiple transmitters, which may be separate components or combined / integrated components, and / or the receiver 354 may include multiple receivers, which may be separate components or combined / integrated components. The wired transceiver 350 may be configured for optical and / or electrical communication, for example. The transceiver 315 may be communicatively coupled to the transceiver interface 314, for example, by optical and / or electrical connections. The transceiver interface 314 may be at least partially integrated with the transceiver 315.

[0090] The antenna 346 may include an antenna array. The antenna array may be capable of transmit or receive beamforming, for example, by increasing the gain setting and / or adjusting the phase setting of the array of antennas in a particular direction to amplify (e.g., increase the gain level of) RF signals received from that direction. The antenna 346 may further include multiple antenna panels, each capable of beamforming. The antenna 346 is capable of adapting, e.g., selecting, one or more antennas to control reception of a beam transmitted from a base station. For example, to reduce power consumption, fewer beams or a single beam may be selected for reception of a wide beam, while a larger number of antennas in the antenna array may be selected when the transmit beam is relatively narrow.

[0091] The user interface 316 may comprise one or more of several devices, such as, for example, a speaker, a microphone, a display device, a vibrating device, a keyboard, a touchscreen, etc. The user interface 316 may include two or more of any of these devices. The user interface 316 may be configured to allow a user to interact with one or more applications hosted by the UE 300. For example, the user interface 316 may store indications of analog and / or digital signals in the memory 311 for processing by the DSP 331 and / or the processor 330 in response to actions from the user. Similarly, applications hosted on the UE 300 may store indications of analog and / or digital signals in the memory 311 for presenting output signals to the user. The user interface 316 may include audio input / output (I / O) devices, including, for example, a speaker, a microphone, digital-to-analog circuitry, analog-to-digital circuitry, an amplifier, and / or gain control circuitry (including two or more of any of these devices). Other configurations of audio I / O devices may be used. Additionally or alternatively, the user interface 316 may include one or more touch sensors that respond to contact and / or pressure, for example, on a keyboard and / or touchscreen of the user interface 316 .

[0092] The SPS receiver 317 (e.g., a global positioning system (GPS) receiver or a global navigation satellite system (GNSS) receiver) may be capable of receiving and acquiring SPS signals 360 via an SPS antenna 362. The antenna 362 is configured to convert the wireless signals 360 into wired signals, e.g., electrical or optical signals, and may be integrated with the antenna 346. The SPS receiver 317 may be configured to process the acquired SPS signals 360, in whole or in part, to estimate the position of the UE 300. For example, the SPS receiver 317 may be configured to determine the position of the UE 300 by trilateration / multilateration using the SPS signals 360. The processor 330, the memory 311, the DSP 331, the PE 319, and / or one or more additional specialized processors (not shown) may be utilized in conjunction with the SPS receiver 317 to process the acquired SPS signals and / or calculate the estimated position of the UE 300, in whole or in part. The memory 311 may store indications (e.g., measurements) of the SPS signals 360 and / or other signals (e.g., signals acquired from the wireless transceiver 340) for use in performing positioning operations. The general-purpose processor 330, the DSP 331, the PE 319, and / or one or more additional specialized processors, and / or the memory 311 may provide or support a location engine for use in processing the measurements to estimate the location of the UE 300.

[0093] The UE 300 may include a camera 318 for capturing still or video images. The camera 318 may comprise, for example, an imaging sensor (e.g., a charge-coupled device or CMOS imager), a lens, analog-to-digital circuitry, a frame buffer, etc. Additional processing, conditioning, encoding, and / or compression of signals representing the captured images may be performed by the general-purpose processor 330 and / or the DSP 331. Additionally or alternatively, a video processor 333 may perform conditioning, encoding, compression, and / or manipulation of signals representing the captured images. The video processor 333 may decode / decompress stored image data, for example, for presentation on a display device (not shown) of the user interface 316.

[0094] The location device (PD) 319 may be configured to determine the location of the UE 300, the movement of the UE 300, and / or the relative location of the UE 300, and / or time. For example, the PD 319 may communicate with and / or include some or all of the SPS receiver 317 and the wireless transceiver 340. The PD 319 may operate in conjunction with the processor 310 and memory 311 as necessary to perform at least a portion of one or more positioning methods, although the description herein may only refer to the PD 319 of the processor 310 being configured to perform or performing in accordance with a positioning method. Additionally or alternatively, the PD 319 may be configured to determine the location of the UE 300 using ground-based signals (e.g., at least some of the signals 348), to assist in acquiring and using SPS signals 360 for trilateration / multilateration, or both. The PD 319 may be configured to use one or more other techniques for determining the location of the UE 300 (e.g., relying on the UE's self-reported location (e.g., as part of the UE's location beacon)), or may use a combination of techniques (e.g., SPS signals and terrestrial positioning signals) to determine the location of the UE 300. The PD 319 may include one or more of the sensors 313 (e.g., gyroscopes, accelerometers, magnetometers, etc.) that may sense the orientation and / or movement of the UE 300 and may provide indications of the orientation and / or movement that the processor 310 (e.g., processor 330 and / or DSP 331) may be configured to use to determine the movement (e.g., velocity vector and / or acceleration vector) of the UE 300. The PD 319 may be configured to provide an indication of uncertainty and / or error in the determined location and / or movement.

[0095] Memory 311 may store software 312, including executable program code or software instructions that, when executed by processor 310, can cause processor 310 to operate as a special-purpose computer programmed to perform the functions disclosed herein. As shown, memory 311 may include one or more components or modules that can be implemented by processor 310 to perform the disclosed functions. While the components or modules are shown as software 312 in memory 311 executable by processor 310, it should be understood that the components or modules may be stored on another computer-readable medium or may be dedicated hardware either within or external to processor 310. Several software modules and data tables may reside in memory 311 and be utilized by processor 310 to manage both the communications and functions described herein. It should be understood that the organization of the contents of memory 311 as shown is exemplary only, and thus the functionality of the modules and / or data structures may be combined, separated, and / or structured in different ways depending on the implementation.

[0096] As described herein, the memory 311 may include an anchor UE selection session module 372 that, for example, when implemented by one or more processors 310, configures the one or more processors 310 to participate in a session to be used to determine whether the UE 300 or another UE will be used for positioning, which may be UE-based or UE-assisted positioning. For example, the one or more processors 310 may be configured to determine a measurement quality metric (such as RSRP, SNR, location estimation accuracy, etc.) or a mobility state or movement metric of the UE 300, which may be used to select the UE 300 or exclude the UE 300 from being used as a TRP, or to select the UE 300 as a TRP for positioning. A GDOP may also be determined or used for filtering or selection. While the anchor UE selection session module 372 is shown as being software contained in the memory 311, the anchor UE selection session module 372 may be a hardware module, a software module, or a combination of hardware and software. For example, a module may include one or more application specific integrated circuits (ASICs), executable code, or a combination of both.

[0097] FIG. 4 illustrates a base station 400 capable of supporting positioning services in a wireless network (such as wireless network 100) and is an example of base station 102. Base station 400 includes a computing platform including at least one processor 410, a memory 411 including software (SW) 412, and a transceiver 415. Processor 410, memory 411, and transceiver 415 may be communicatively coupled to each other by a bus 420 (which may be configured for optical and / or electrical communications, for example). One or more of the devices shown may be omitted from base station 400, or base station 400 may include one or more devices not shown. Processor 410 may include one or more intelligent hardware devices, e.g., a central processing unit (CPU), a microcontroller, an application-specific integrated circuit (ASIC), etc. Processor 410 may comprise multiple processors (e.g., including one or more of an application processor, a DSP, a modem processor, a video processor, and / or a sensor processor, similar to those shown in FIG. 3). Memory 411 is a non-transitory storage medium that may include random access memory (RAM), flash memory, disk memory, and / or read-only memory (ROM), etc. Memory 411 stores software 412, which may be processor-readable, processor-executable software code including instructions that, when executed, are configured to cause processor 410 to operate as a special-purpose computer programmed to perform various functions described herein. Alternatively, software 412 may not be directly executable by processor 410, but may be configured, for example, when compiled and executed, to cause processor 410 to operate as a special-purpose computer to perform various functions described herein. While this description may only refer to processor 410 performing functions, this includes other implementations, such as processor 410 executing software and / or firmware.The description may refer to the processor 410 performing a function as shorthand for one or more of the processors included in the processor 410 performing the function. The description may refer to the base station 400 performing a function as shorthand for one or more suitable components of the base station 400 performing the function. The processor 410 may include memory with stored instructions in addition to and / or instead of the memory 411.

[0098] The transceiver 415 may include a wireless transceiver 440 and a wired transceiver 450 configured to communicate with other devices over wireless and wired connections, respectively. For example, the wireless transceiver 440 may include a transmitter 442 and a receiver 444 coupled to one or more antennas 446 to transmit and / or receive wireless signals 448 (e.g., on one or more uplink channels and / or one or more downlink channels) and convert signals from the wireless signals 448 to wired (e.g., electrical and / or optical) signals and from the wired (e.g., electrical and / or optical) signals to the wireless signals 448. The antennas 446 are one or more antenna arrays capable of beamforming and capable of transmitting and receiving beams, including beams used in transmitting or receiving signals for positioning services (including PRS). Additionally or alternatively, signals may be transmitted omnidirectionally. The transmitter 442 may include multiple transmitters, which may be separate components or combined / integrated components, and / or the receiver 444 may include multiple receivers, which may be separate components or combined / integrated components. The wireless transceiver 440 may be configured to communicate signals (e.g., with the UE 300, one or more other UEs, and / or one or more other devices) according to various radio access technologies (RATs), such as 5G New Radio (NR), Global System for Mobiles (GSM), Universal Mobile Telecommunications System (UMTS), Advanced Mobile Phone System (AMPS), Code Division Multiple Access (CDMA), Wideband CDMA (WCDMA), Long-Term Evolution (LTE), LTE Direct (LTE-D), 6GPP LTE-V2X (PC5), IEEE 802.11 (including IEEE 802.11p), WiFi, WiFi Direct (WiFi-D), Bluetooth, Zigbee, etc.Wired transceiver 450 may include a transmitter 452 and a receiver 454 configured for wired communication, for example, to send communications to and receive communications from location server 172. Transmitter 452 may include multiple transmitters, which may be separate components or combined / integrated components, and / or receiver 454 may include multiple receivers, which may be separate components or combined / integrated components. Wired transceiver 450 may be configured for optical and / or electrical communication, for example.

[0099] 4 is an example, not a limitation, of the present disclosure, including the claims, and other configurations may be used. For example, the description herein discusses the base station 400 being configured to or performing certain functions, but one or more of these functions may be performed by the location server 172 and / or the UE 300.

[0100] The memory 411 may store software 412, including executable program code or software instructions that, when executed by the processor 410, can cause the processor 410 to operate as a special-purpose computer programmed to perform the functions disclosed herein. As shown, the memory 411 may include one or more components or modules that can be implemented by the processor 410 to perform the disclosed functions. While the components or modules are shown as software 412 in the memory 411 executable by the processor 410, it should be understood that the components or modules may be stored on another computer-readable medium or may be dedicated hardware either within or external to the processor 410. Several software modules and data tables may reside in the memory 411 and be utilized by the processor 410 to manage both the communications and the functions described herein. It should be understood that the organization of the contents of the memory 411 as shown is exemplary only, and thus the functionality of the modules and / or data structures may be combined, separated, and / or structured in different ways depending on the implementation.

[0101] The memory 411 may include, for example, an anchor UE selection session module 472 that, when implemented by the processor 410, configures the processor 410 to assist in selecting or narrowing down one or more anchor UEs for positioning. For example, the one or more processors 410 may configure the base station 400 to relay information between the location server 172 and one or more anchor UE candidates. While the anchor UE selection session module 472 is shown as being software contained in the memory 411, the anchor UE selection session module 472 may be a hardware module, a software module, or a combination of hardware and software. For example, the module may include one or more application-specific integrated circuits (ASICs), executable code, or a combination of both.

[0102] FIG. 5 illustrates a server 500 capable of supporting positioning services in a wireless network (such as wireless network 100) and is an example of location server 172. Server 500 includes a computing platform including at least one processor 510, a memory 511 including software (SW) 512, and a transceiver 515. Processor 510, memory 511, and transceiver 515 may be communicatively coupled to each other by a bus 520 (which may be configured for optical and / or electrical communication, for example). One or more of the illustrated devices (e.g., a wireless interface) may be omitted from server 500. Processor 510 may include one or more intelligent hardware devices, such as a central processing unit (CPU), a microcontroller, an application-specific integrated circuit (ASIC), etc. Processor 510 may comprise multiple processors (e.g., including at least one of an application processor, a DSP, a modem processor, a video processor, and / or a sensor processor, similar to those illustrated in FIG. 5). Memory 511 is a non-transitory storage medium that may include random access memory (RAM), flash memory, disk memory, and / or read-only memory (ROM), etc. Memory 511 stores software 512, which may be processor-readable, processor-executable software code including instructions that, when executed, are configured to cause processor 510 to operate as a special-purpose computer programmed to perform various functions described herein. Alternatively, software 512 may not be directly executable by processor 510, but may be configured, for example, when compiled and executed, to cause processor 510 to operate as a special-purpose computer to perform various functions described herein. While this description may only refer to processor 510 performing functions, this includes other implementations, such as processor 510 executing software and / or firmware.The description may refer to processor 510 performing a function as shorthand for one or more of the processors included in processor 510 performing the function. The description may refer to server 500 performing a function as shorthand for one or more suitable components of server 500 performing the function. Processor 510 may include memory having stored instructions in addition to and / or in place of memory 511.

[0103] The transceiver 515 may include one or both of a wireless transceiver 540 or a wired transceiver 550 configured to communicate with other devices over wireless and wired connections, respectively. For example, the wireless transceiver 540 may include a transmitter 542 and a receiver 544 coupled to one or more antennas 546 to transmit (e.g., on one or more downlink channels) and / or receive (e.g., on one or more uplink channels) wireless signals 548 and convert signals from the wireless signals 548 to wired (e.g., electrical and / or optical) signals and from the wired (e.g., electrical and / or optical) signals to the wireless signals 548. Thus, the transmitter 542 may include multiple transmitters, which may be separate components or combined / integrated components, and / or the receiver 544 may include multiple receivers, which may be separate components or combined / integrated components. The wireless transceiver 540 may be configured to communicate signals (e.g., with the base station 400 (e.g., a gNB), one or more other base stations, the UE 300, one or more other UEs, and / or one or more other devices) according to various radio access technologies (RATs), such as 5G New Radio (NR), Global System for Mobiles (GSM), Universal Mobile Telecommunications System (UMTS), Advanced Mobile Phone System (AMPS), Code Division Multiple Access (CDMA), Wideband CDMA (WCDMA), Long-Term Evolution (LTE), LTE Direct (LTE-D), 6GPP LTE-V2X (PC5), IEEE 802.11 (including IEEE 802.11p), WiFi, WiFi Direct (WiFi-D), Bluetooth, Zigbee, etc. The wired transceiver 550 may include a transmitter 552 and a receiver 554 configured for wired communication.The transmitter 552 may include multiple transmitters, which may be separate components or combined / integrated components, and / or the receiver 554 may include multiple receivers, which may be separate components or combined / integrated components. The wired transceiver 550 may be configured for optical and / or electrical communications, for example.

[0104] 5 is an example, not a limitation, of the present disclosure, including the claims, and other configurations may be used. For example, wireless transceiver 540 may be omitted. Additionally or alternatively, although the description herein discusses server 500 being configured to or performing certain functions, one or more of these functions may be performed by base station 400 and / or UE 300.

[0105] The memory 511 may store software 512, including executable program code or software instructions that, when executed by the processor 510, may cause the processor 510 to operate as a special-purpose computer programmed to perform the functions disclosed herein. As shown, the memory 511 may include one or more components or modules that may be implemented by the processor 510 to perform the disclosed functions. While the components or modules are shown as software 512 in the memory 511 executable by the processor 510, it should be understood that the components or modules may be stored on another computer-readable medium or may be dedicated hardware either within or external to the processor 510. Several software modules and data tables may reside in the memory 511 and be utilized by the processor 510 to manage both the communications and the functions described herein. It should be understood that the organization of the contents of the memory 511 as shown is merely exemplary, and thus the functionality of the modules and / or data structures may be combined, separated, and / or structured in different ways depending on the implementation.

[0106] As discussed herein, the memory 511 may include, for example, an anchor UE selection session module 572 that, when implemented by the processor 510, configures the processor 510 to participate in supporting the selection or refinement of one or more anchor UEs for positioning. While the anchor UE selection session module 572 is shown as being software contained in the memory 511, the anchor UE selection session module 572 may be a hardware module, a software module, or a combination of hardware and software. For example, the module may include one or more application specific integrated circuits (ASICs), executable code, or a combination of both.

[0107] Positioning uses one or more anchors as TRPs for transmitting and / or receiving PRSs to / from a target UE. The distance between the TRP and the target UE may be based on the observed time difference of arrival (OTDOA) of one or more signals (referred to as OTDOA positioning) or any other suitable measurement used to determine distance for positioning purposes. OTDOA positioning is based on a multilateration method in which the UE conventionally measures the time of arrival (TOA) of a particular reference RF signal (e.g., PRS, CRS, CSI-RS, etc.) transmitted by different pairs of network nodes (e.g., base station 102, antennas of base station 102, other UEs 104, etc.). To determine the reference signal time difference (RSTD) for a node pair, the TOA from several neighbors may be subtracted from the TOA from the reference node. As mentioned above, this time difference may be based on a reference signal (such as a PRS) transmitted from the anchor to the UE, but the time difference may also be based on the signal from the UE to the anchor or the round trip time (RTT) from the anchor back to the anchor or neighboring device (the UE relays the PRS). RSTD may be indicated to another device or may be otherwise used in determining the distance between the anchor and the UE. In some implementations, the anchor (and similarly anchor candidate) or target UE may measure RSTD between instances of the PRS transmitted by other devices in the network. In some implementations, specific resources of the PRS may be used to measure RSTD. As used herein, PRS resources may refer to any appropriate portion or all of the PRS used for positioning.

[0108] FIG. 6 illustrates an exemplary wireless communications system 600 that implements positioning using a time difference of arrival (TDOA) technique. In the example of FIG. 6, the UE 104 determines or assists another entity (e.g., a base station or core network component, another UE, a location server, a third-party application, etc.) to determine an estimate of the UE 104's location. The UE 104 may communicate wirelessly with multiple base stations 102-1, 102-2, and 102-3 (collectively, base stations 102), which may correspond to any combination of the base stations 102 in FIG. 1, using RF signals and standardized protocols for modulation of the RF signals and exchange of information packets. By extracting different types of information from the exchanged RF signals and utilizing the layout of the wireless communications system 600 (i.e., base station locations, geometric arrangements, etc.), the UE 104 may determine or assist in determining the location of the UE 104 in a predetermined reference coordinate system. In some aspects, the UE 104 may specify its location using a two-dimensional coordinate system, although the aspects disclosed herein are not so limited and may be applicable to determining location using a three-dimensional coordinate system if additional dimensions are desired. Additionally, while FIG. 6 shows one UE 104 and three base stations 102, it will be understood that there may be more UEs 104 and more or fewer base stations 102 as anchors, or one or more anchors may be UEs 104 of the wireless network, as described herein. For example, any of the base stations 102-1 through 102-3 may be replaced by an anchor UE for positioning purposes.

[0109] Typically, RSTD is measured between a reference network node and one or more neighboring network nodes. In the example shown in FIG. 6, base station 102-1 may be the serving base station for UE 104 and may also function as a reference base station, while base stations 102-2 and 102-3 function as neighboring base stations. The reference network node remains the same for all RSTD measured by UE 104 for positioning using OTDOA and typically corresponds to the serving cell for UE 104 or another nearby cell with good signal strength at UE 104. In an aspect, if the measured network node is a cell supported by a base station, the neighboring network node is typically a cell supported by a different base station than the base station for the reference cell, and may have good or bad signal strength at UE 104. RSTD may be the relative timing difference between two cells, e.g., between a reference cell and a neighboring cell, which is determined based on the minimum time difference between two subframe boundaries from two different cells.

[0110] The position calculation may be based on measured time differences (e.g., RSTD) and knowledge of the network nodes' locations and relative transmission timing (e.g., whether the network nodes are precisely synchronized or whether each network node transmits with some known time difference relative to other network nodes).

[0111] To assist in positioning operations, the location server 172 may provide OTDOA assistance data to the UE 104 for a reference network node (e.g., base station 102-1 in the example of FIG. 6 or an anchor UE in another example) and neighboring network nodes relative to the reference network node (e.g., base stations 102-2 and 102-3 in the example of FIG. 6 or one or more other anchors, which may include the anchor UE in another example). For example, as described above, the assistance data may include base station and reference signal (e.g., PRS) configuration information and may provide a center channel frequency for each network node, various reference RF signal configuration parameters (e.g., number of consecutive positioning subframes, periodicity of positioning subframes, muting sequence, frequency hopping sequence, reference RF signal ID, reference RF signal bandwidth), network node global ID, and / or other cell-related parameters applicable to OTDOA. The OTDOA assistance data may also indicate the serving cell for the UE 104 as the reference network node.

[0112] In an aspect, the location server 172 may transmit the assistance data to the UE 104, but alternatively, the assistance data may originate directly from the network node (e.g., the base station 102 or the anchor UE) itself (e.g., in a periodically broadcast overhead message, etc.) Alternatively, the UE 104 may detect neighboring network nodes itself without using assistance data.

[0113] 6, the time differences measured between the reference cell of base station 102-1 and the neighboring cells of base stations 102-2 and 102-3 are represented as τ−τ and τ−τ, where τ, τ, and τ represent the transmission times of the reference RF signals from the transmit antennas of base stations 102-1, 102-2, and 102-3, respectively, to UE 104, and include any measurement noise at UE 104. UE 104 may then convert the TOA measurements of different network nodes into RSTD measurements (e.g., as defined in 3GPP TS 36.214 entitled “Physical layer; Measurements”). The location of the UE 104 may be determined (either by the UE 104 or the location server 172) using (i) RSTD measurements, (ii) the known absolute or relative transmission timing of each network node, (iii) the known location of the physical transmitting antenna relative to the reference network node and neighboring network nodes, and / or (iv) directional reference RF signal characteristics such as transmission direction.

[0114] TOA T at UE 104 for the shortest path from base station i i teeth,

[0115]

number

[0116] where D i is the position (q i ) and the UE 104 at location (p), c is the speed of light in air (299700 km / s), and q i is known through a cell information database (which may be contained in a location server or another network component). The geometric distance (i.e., the straight-line distance between two points) is given by equation (1) below:

[0117]

number

[0118] where D is the distance between two points on the Earth's surface, and R is the Earth's radius (6371 km),

[0119]

number

[0120] ,

[0121]

number

[0122] are the latitudes (in radians) of the first point and the second point, respectively, and β1, β2 are the longitudes (in radians) of the first point and the second point, respectively. If the anchor is a UE rather than a base station, q i may be unknown to the anchor UE. In this way, to determine the location of UE 104 in Figure 6 when the anchor is another UE, the location of the anchor UE is to be determined.

[0123] To determine the TOA of a reference RF signal transmitted by a given network node, the UE 104 first processes all resource elements (REs) on the channel on which that network node (e.g., base station 102) is transmitting the reference RF signal together and performs an inverse Fourier transform to convert the received RF signal to the time domain. Converting the received RF signal to the time domain is called estimating the channel energy response (CER). The CER indicates the peaks on the channel over time, and therefore the earliest “significant” peak should correspond to the TOA of the reference RF signal. Typically, the UE uses a noise-related quality threshold to remove spurious local peaks, thereby correctly identifying the likely significant peaks on the channel. For example, the UE 104 may choose a TOA estimate that is the earliest local maximum of the CER that is at least X dB higher than the median CER and up to Y dB lower than the main peak on the channel. To determine the TOA of each reference RF signal from different network nodes, the UE 104 determines the CER for each reference RF signal from each network node.

[0124] The TOA measurements performed by the UE 104 relate to the geographic distance between the UE 104 and the anchor (e.g., base station 102). In a 2D Cartesian coordinate system, the (known) coordinates of the base station or the determined coordinates of the anchor UE are x i =[x i ,y i ] T and the (unknown) coordinates of the UE 104 are x t =[x t ,y t ] T The RSTD measurement result may be defined as the time difference between two nodes (e.g., base stations) (modulo 1-subframe (1-ms)) and may therefore correspond to the difference in distance between a neighbor base station 102-i and the reference base station 102-1. The time difference between a neighbor base station 102-i and the reference base station 102-1, as measured at the UE 104, is given in equation (2) below:

[0125]

number

[0126] (T i -T1) is the transmission time offset between base stations, called the "real time difference" (RTD). i and n1 is the UE TOA measurement error. The constant c is the speed of light.

[0127] Measurements of at least two neighboring anchors (e.g., base stations) i may be required, but measurements of more than two neighboring anchors may be desirable, and the simultaneous equations may be solved in a least squares or weighted least squares manner. i -T1) should be zero (ideally) in a synchronized network, and the above equation defines the TDOA. Geometrically, each TDOA defines a hyperbola, and the width of the hyperbola is the TDOA error (n i - n1) is determined by the coordinates of the base station 102 and the transmission time offset (T i -T1) is known at the location server 172 or at the UE 104, the location of the UE 104 can be determined. Uncertainty in the anchor coordinates or transmission time offset directly affects the accuracy of the UE position estimate.

[0128] Positioning may be UE-assisted or UE-based. In UE-assisted positioning, a server 500 (e.g., location server 172) may determine the position / location of a target UE. For clarity, the location server 172 is described as performing the operations, but one or more other network entities in the wireless network may perform all or some of the described operations (e.g., base stations, core network components, etc.). The location server 172 may also determine the RS resources to be used for positioning (specific PRS format, frequency, time slot, whether PRS transmission is triggered or periodic, etc.). The location server 172 may also select which base station 102 should be used as a TRP for positioning and the configuration for the TRP (e.g., which UEs should be supported, etc.). The location server 172 may indicate the determined resources to the base station 102 (e.g., gNB), which may indicate the resources to the UE 104 or transmit the PRS using that indication. As described herein, one or more UEs 104 may be used as anchors for positioning. In some implementations, the location server 172 may narrow down or select anchor UE candidates to be used as anchor UEs for positioning. The narrowing down or selection may be based on anchor UE preferences from one or more target UEs. Alternatively, the narrowing down or selection may be performed independently of any preferences from the target UE. As described herein, the narrowing down or selection may be based on one or more measurement qualities, one or more mobility states, one or more GDOPs. In UE-based positioning, the target UE may determine its location / positioning based on PRS measurements performed and provided by other devices and / or PRS measurements performed by the target UE (such as from an RSTD as described above).The target UE (or location server or another network entity) may narrow down or select anchors for positioning (such as determining which PRS from which device to use or which measurements from devices to use for positioning). In some implementations, the target UE (or location server or another network entity) may select or narrow down candidate anchor UEs to be used as anchor UEs.

[0129] As described above, one or more UEs may be used as anchors for positioning, where the anchor UE transmits and / or receives PRS over a sidelink (e.g., a PC5 connection) and otherwise communicates with the target UE over the sidelink. In this way, the anchor UE, similar to an anchor base station, may act as a TRP for positioning. The accuracy of a target UE's location estimation based on one or more anchor UEs depends on the accuracy of the anchor UE's determined location. For example, referring to equation (2) above, errors in the anchor UE's coordinates cause errors in the target UE's estimated location. A base station (e.g., a gNB) may not change its defined location. However, a UE may move, and the UE's location will be determined and used if the UE becomes an anchor UE. For an anchor UE, transmission strength or other factors may also vary. The accuracy of an anchor UE candidate's determined location, or the anchor UE candidate's suitability as an anchor, may depend on the UE's mobility, UE's transmission strength, or other factors. For example, a fast-moving anchor UE may cause measurements (e.g., RSTD) related to the PRS to / from the anchor UE to become stale sooner or may be associated with higher Doppler effects or interference. The location determined for the anchor UE will also be updated and may have more error or be determined with less accuracy (thus affecting the accuracy of the target UE's position estimate). In another example, lower transmit power of the anchor UE or interference with the PRS at the anchor UE may cause the PRS's RSRP or SNR to be lower, which may make it difficult or inaccurate to process the PRS to determine RSTD or other measures. Additionally or alternatively, the anchor UE (and other anchors) may be associated with a GDOP based on the anchor UE's location and the locations of other anchors relative to the target UE. An anchor UE associated with a smaller GDOP may be associated with a more accurate position determination of the target UE. In addition, a moving anchor UE causes changes in the GDOP, which introduces uncertainty into the accuracy of the position estimate.GDOP is described in further detail below with respect to FIG.

[0130] As described herein, one or more devices (e.g., one or more of one or more anchor UE candidates, target UEs, or location servers) may perform operations to narrow down or select anchor UE candidates as anchor UEs for positioning of one or more target UEs. As mentioned above, narrowing down as used herein refers to removing or excluding one or more candidates from being used as anchors for the target UE. As described herein, narrowing down (or generally selecting) may be based on metrics from one or more anchor UE candidates (e.g., PRS or RSRP or SNR of another signal), mobility states of one or more anchor UE candidates (e.g., based on IMU measurements, GNSS measurements, and / or positioning estimates of the anchor UE candidates), or GDOPs associated with different combinations of the anchor UE candidates with other anchor UE candidates and / or base stations. The selecting (e.g., narrowing down) or other operations may be performed by one or more of a location server, an anchor UE candidate, a target UE, another UE, a base station (e.g., a gNB), or another appropriate network entity of the wireless network. Because the measurement quality of location measurements of anchor UE candidates, the mobility state of anchor UE candidates, or the GDOP associated with anchor UE candidates may change over time, one or more devices may repeat operations or otherwise adjust which devices are used as anchors for positioning (e.g., periodically or based on a trigger). Exemplary operations in selecting or narrowing down anchor UE candidates or otherwise related to positioning are described in more detail below.

[0131] FIG. 7 shows a flowchart of an example method 700 for selecting an anchor UE for positioning of a target UE in a wireless network. As used herein, selecting an anchor UE may refer to selecting an anchor UE candidate as the anchor UE, or alternatively, filtering out one or more anchor UE candidates from being used as the anchor UE or otherwise reducing the number of anchor UE candidates. For example, a subset of the anchor UE candidates may be selected to remain potential anchor UEs, while unselected anchor UE candidates may be removed from consideration. The example method 700 may be performed by any appropriate device of a wireless network, such as the target UE 104 or location server 172 shown in FIG. 1 , in a manner consistent with disclosed implementations. For example, the method 700 may be performed by the target UE 104 for UE-based positioning or by the location server 172 for UE-assisted positioning. A device that may perform one or more operations of method 700 (or any of the other described methods, such as method 800 of FIG. 8 or method 1000 of FIG. 10) may include at least one transceiver (such as one or more wireless transceivers and / or one or more wired transceivers), at least one memory, and at least one processor coupled to the at least one transceiver and the at least one memory. Referring to UE 300 as an exemplary device, the at least one transceiver may include transceiver 315 or wireless transceiver 340, the at least one memory may include memory 311, and the at least one processor may include one or more of processors 310, one or more of processors 330 through 334, or location device 319. Referring to base station 400 as an exemplary device, the at least one transceiver may include all or a portion of transceiver 415, the at least one memory may include memory 411, and the at least one processor may include processor 410.Referring to server 500 (e.g., a location server) as an exemplary device, the at least one transceiver may include all or a portion of transceiver 515, the at least one memory may include memory 511, and the at least one processor may include processor 510.

[0132] In block 702, the device obtains, from one or more of a plurality of anchor UE candidates, one or more location measurements of the anchor UE candidates and a measurement quality metric for each of the one or more location measurements. The means for obtaining the one or more location measurements and the measurement quality metric for each of the one or more location measurements may include at least one transceiver of the device. As mentioned above, when a UE is used as an anchor for positioning, the position / location of the anchor UE is required because the position estimation of the target UE is based on the location of the anchor used for positioning. The anchor UE candidate may generate (or one or more other devices may determine) location measurements of the anchor UE candidate. The location measurements may include an estimate of the location of the anchor UE candidate or measurement results (such as one or more RSTDs) that can be used to determine / estimate the location of the anchor UE candidate.

[0133] In some implementations, the anchor UE candidate may generate location measurements that are independent of the radio access technology (RAT). In this way, the location measurements and measurement quality are not associated with the wireless network (wireless network 100 for the UE 104). For example, the location measurements and measurement quality measures may be based on GPS or other GNSS. The location of the anchor UE candidate may be determined using a GNSS receiver, which is independent of a wireless transceiver associated with one or more RATs. Additionally or alternatively, the location may be determined or adjusted based on measurements from an IMU or other sensor. In some other implementations, the location measurements may be RAT dependent. For example, the location measurements may include an RSTD measured by the anchor UE candidate using PRS resources obtained from one or more devices in the wireless network (such as one or more base stations 102 for UE-assisted positioning or the target UE 104 for UE-based positioning). As mentioned above, the RSTD may be used to determine the location of a device based on the location of the device transmitting the PRS. For example, a candidate anchor UE may measure RSTD based on three base stations within range of the candidate anchor UE so that the location of the candidate anchor UE may be determined.

[0134] The measurement quality metric of a location measurement may be associated with the accuracy of the location / position that is or will be estimated for the candidate anchor UE. For example, if the location measurement is a position determined at the UE using a GNSS receiver (such as the SPS receiver 317), the measurement quality metric may be associated with the tolerance (potential error) of the estimated position. For example, the receiver may be associated with a potential error of a few inches or a few meters, and the UE's estimated position may differ from its actual position by up to that potential error. The magnitude of the potential error may be based on the number of positioning satellites connected to the receiver (more satellites provide a higher accuracy for the estimated position) or the satellite resolution (e.g., timing indicated by a positioning satellite with higher resolution, which may increase the accuracy of the estimated position). Exemplary measurement quality metric for location measurements related to positioning satellites may include the number of positioning satellites used, the timing resolution or position resolution of the positioning satellites, or other suitable measures. In some implementations, the measurement quality may include an indication that GNSS-based positioning is used instead of ground-based positioning (which may be more accurate than ground-based positioning).

[0135] If the one or more location measurements include one or more RSTDs (or locations determined from the RSTDs) measured by the anchor UE candidate using PRS resources obtained from devices in the wireless network, a measurement quality measure may be associated with a quality that may affect the determination of the RSTD. Exemplary measurement quality measures may include the RSRP of the obtained PRS, the SNR of the obtained PRS, or other suitable indications related to the power or quality of the RS. Additionally or alternatively, the measurement quality measure may be associated with the accuracy of the location that may be determined from the RSTD. For example, a first RSTD may be associated with a larger tolerance (potential error) of any determined location than a second RSTD based on the timing of the PRS, the resolution of indicating or measuring the timing of the PRS, or other factors. Exemplary measurement quality measures may include the timing of the PRS or the resolution of measuring or indicating the timing of the PRS.

[0136] One or more location measurement results and associated measurement quality measures may be included in one or more positioning-related measurement reports. For example, a candidate anchor UE may provide a positioning-related measurement report including the location measurement results and the measurement quality measures. In UE-assisted positioning, the report may be provided to the location server 172 (via the base station 102 (and optionally the relay UE) and the core network 170). In UE-based positioning, the report may be provided to the target UE. In some implementations, a device performing the operations of method 700 may obtain one or more location measurement results and measurement quality measures in one or more NR-based positioning-related measurement reports from a candidate anchor UE. For example, the NR-based positioning-related measurement report may include an NR positioning-related measurement report of the UE configured to include the measurement quality measure (such as defined in Release 16 of the 3GPP set of standards related to 5G NR).

[0137] In UE-based positioning, the device performing the operations of method 700 may be a target UE, and positioning-related measurement reports may be obtained by the target UE from a candidate anchor UE via a sidelink between the target UE and the candidate anchor UE. PRS resources obtained by the candidate anchor UE for determining location measurement results and measurement quality measures in the positioning-related measurement reports may be transmitted by the target UE. In this manner, the candidate anchor UE determines the measurement results and measures from the PRS obtained via the sidelink with the target UE and provides positioning-related measurement reports via the sidelink to the target UE.

[0138] In UE-assisted positioning, the device that performs the operations of method 700 may be a location server. If the positioning-related measurement reports are based on NR, the gNB may provide one or more PRS resources to the anchor UE candidate on the downlink, and the anchor UE candidate may provide the positioning-related measurement reports to the gNB on the uplink. The gNB may provide location measurement results and measurement quality measures from the reports to the location server. In this manner, the location server may obtain location measurement results and measurement quality measures for multiple anchor UE candidates.

[0139] At block 704, the device may select at least one anchor UE candidate from multiple anchor UE candidates for positioning of the target UE based on one or more measurement quality metrics from the one or more anchor UE candidates. In some implementations, the device may narrow down the multiple anchor UE candidates for positioning of the target UE to still include at least one anchor UE candidate based on one or more measurement quality metrics from the one or more anchor UE candidates. In this manner, one or more anchor UE candidates may be excluded from consideration as anchors. In some implementations, the device may select at least one anchor UE candidate as an anchor for the target UE. Means for selecting from or narrowing down the multiple anchor UE candidates may include at least one processor of the device. In some implementations, selecting or narrowing down the multiple anchor UE candidates may include limiting the number of anchor UE candidates (or overall anchor candidates) to a maximum number. For example, if the number of anchor candidates is to be limited to four and the measurement quality metric is timing resolution, the device may exclude one or more anchor candidates whose measured timing resolution was less than the top four timing resolutions among the anchor candidates. In some implementations, selecting or narrowing down multiple anchor UE candidates may include eliminating one or more anchor UE candidates based on one or more measurement quality thresholds. For example, the device may eliminate an anchor UE candidate if the measured timing resolution from the UE is less than the timing resolution threshold. In some implementations, selecting or narrowing down multiple anchor UE candidates may include eliminating one or more anchor UE candidates based on a variance of a measurement quality measure. The device may obtain a measurement quality measure for each of the multiple anchor UE candidates, the device may determine a variance of the measurement quality measure, and the device may eliminate an anchor UE candidate based on a comparison of the variance to the UE's associated measurement quality measure. For example, the device may determine a mean and a variance of the measured quality measure.Although mean and variance are described, other measures of distribution, such as the parameter distribution of the measurement quality measure, may be used, including median, standard deviation, quantiles, etc. After determining the mean and variance, selecting or narrowing down may be based on the measurement quality measure being within a certain multiple of the variance from the mean. For example, any anchor UE candidate associated with a measurement quality measure less than the mean minus one variance may be excluded from being used as an anchor UE for positioning. Note that excluding an anchor UE candidate may be for one or more target UEs. In some implementations, the anchor UE candidate may continue to be used as an anchor for one or more other UEs in the wireless network. Thus, excluding an anchor UE candidate for positioning of a target UE does not require that the anchor UE candidate be excluded from being used as an anchor for positioning of any and all UEs in the wireless network. Also, as used herein, the term selecting may refer to narrowing down, excluding, or selecting at least one anchor UE candidate.

[0140] Because the anchor UE transmits to or receives from the target UE via the sidelink, the link quality of the sidelink may also affect the positioning of the target UE. For example, a noisy sidelink may prevent the PRS from being received or decoded. The selection may be based on the link quality of the sidelink between the target UE and the candidate anchor UE. The candidate anchor UE or the target UE may determine a link quality metric for the sidelink (SINR, SNR, RSRP, etc.), and the link quality metric for the sidelink may be taken into consideration for the selection. For example, a candidate anchor UE may be eliminated if its SNR of the sidelink is below an SNR threshold. Using the link quality metric for the selection may be performed in any suitable manner, such as any of the methods described above for measuring quality metrics.

[0141] When a device selects a candidate anchor UE to be used as an anchor UE for positioning, the device may indicate the selection to the anchor UE, and the anchor UE may be configured to transmit a PRS to or receive a PRS from the target UE. For example, in UE-assisted positioning, the location server 172 may indicate the selection to one or more base stations (e.g., gNBs), which may indicate the selection to a suitable UE to be used as an anchor. This indication may also be provided to the target UE. In UE-based positioning, the target UE may indicate its selection to each anchor UE via a respective sidelink.

[0142] Although method 700 is shown as being performed for a single selection or refinement for clarity in describing aspects of the present disclosure, a device may be configured to perform the selection or refinement multiple times. For example, anchor UE candidates may periodically provide positioning-related measurement reports. If the anchor UE's location measurements change by more than a threshold, if the measurement quality metric changes by more than a threshold (or no longer meets the initial selection criteria used to select the anchor UE), or if the link quality metric changes by more than a threshold or falls below a threshold, the device may again refine the anchor UE candidates or select an anchor UE for positioning. In this way, which anchor UEs are used for positioning may be adjusted over time.

[0143] As noted above, method 700 of Figure 7 relates to location measurements of candidate anchor UEs (the accuracy of the anchor UE's determined location affects the accuracy of the target UE's determined location). Additionally or alternatively, which anchor UE should be used may be based on the mobility state of each candidate anchor UE, as described below in connection with Figure 8.

[0144] 8 shows a flowchart of an example method 800 for selecting an anchor UE for positioning of a target UE in a wireless network. The example method 800 may be performed by any appropriate device of a wireless network, such as the target UE 104 or the location server 172 shown in FIG. 1 , in a manner consistent with the disclosed implementations. For example, the method 800 may be performed by the target UE 104 for UE-based positioning or by the location server 172 for UE-assisted positioning. A device that may perform one or more operations of the method 800 may include at least one transceiver (such as one or more wireless transceivers and / or one or more wired transceivers), at least one memory, and at least one processor coupled to the at least one transceiver and the at least one memory. Referring to UE 300 as an exemplary device, the at least one transceiver may include transceiver 315 or wireless transceiver 340, the at least one memory may include memory 311, and the at least one processor may include one or more of processors 310, one or more of processors 330-334, or location device 319. Referring to base station 400 as an exemplary device, the at least one transceiver may include all or a portion of transceiver 415, the at least one memory may include memory 411, and the at least one processor may include processor 410. Referring to server 500 (e.g., a location server) as an exemplary device, the at least one transceiver may include all or a portion of transceiver 515, the at least one memory may include memory 511, and the at least one processor may include processor 510.

[0145] In block 802, the device acquires, for one or more of a plurality of anchor UE candidates, an anchor UE candidate mobility state. The means for acquiring the mobility state may include one or more of at least one transceiver, at least one memory, or at least one processor of the device. In some implementations, acquiring the mobility state of the anchor UE candidate refers to the anchor UE candidate determining the mobility state and the device acquiring the mobility state from the anchor UE candidate. The anchor UE candidate may determine the mobility state using a method independent of the RAT. For example, the anchor UE candidate may use IMU measurements (such as accelerometer or other sensor measurements) to determine the anchor UE candidate's movement. In another example, the anchor UE candidate may determine its position difference based on GNSS measurements over time to determine the anchor UE candidate's movement. The movement may be speed, velocity, acceleration, displacement, or other indication of the anchor UE candidate's mobility. Additionally or alternatively, the anchor UE candidate may determine the mobility state using a RAT-dependent method. For example, a candidate anchor UE may determine its location using RSTD (such as that described above) at different times, and the candidate anchor UE may determine its movement based on the difference in location over time. The movement may be speed, velocity, acceleration, displacement, Doppler shift, or other indication of the candidate anchor UE's mobility. The mobility state may be provided in any suitable manner, such as in an NR-based positioning-related measurement report from the candidate anchor UE to the target UE or location server. For example, in UE-based positioning, the target UE may obtain the mobility state from the candidate anchor UE via a sidelink between the target UE and the candidate anchor UE.

[0146] In some implementations of obtaining the mobility state, the device itself determines the mobility state of the anchor UE candidate. For example, the device may determine the mobility state of the anchor UE candidate from the location history of the anchor UE candidate. In UE-assisted positioning, the location server 172 may perform the operations of method 800. In this manner, the location server 172 may determine the mobility state of the anchor UE candidate from the location history. In some implementations, the location server 172 may include a database of locations for one or more UEs. The location may be determined from an RSTD (such as that described above) obtained for the UE, and the UE or another device provides a positioning-related measurement report that includes the RSTD. In this manner, the location server 172 may determine the location history. The location server 172 may use the UE's location (and optionally the time of location) to determine the UE's movement (which may include speed, velocity, acceleration, displacement, etc.). In UE-based positioning, the positioning-related measurement report may be provided to the target UE, and the target UE may determine the location history of the anchor UE candidate over time.

[0147] At block 804, the device may select at least one anchor UE candidate from multiple anchor UE candidates for positioning of the target UE based on one or more mobility states. In some implementations, the device may narrow down the multiple anchor UE candidates for positioning of the target UE based on one or more mobility states. Means for selecting at least one anchor UE candidate (e.g., narrowing down the multiple anchor UE candidates) may include at least one processor of the device. In some implementations, selecting or narrowing down the multiple anchor UE candidates may include eliminating one or more anchor UE candidates based on one or more mobility state thresholds. For example, the device may exclude an anchor UE candidate if the speed of the UE is greater than a speed threshold. In some implementations, selecting or narrowing down the multiple anchor UE candidates may include eliminating one or more anchor UE candidates based on mobility state variations. For example, the device may determine that the mobility state of the anchor UE candidate fluctuates (e.g., changes in speed, displacement, etc. over time) more than a threshold number of times within a certain length of time, which may indicate a change in the movement of the anchor UE candidate. The device may exclude anchor UE candidates from being used based on the number of fluctuations being greater than a threshold number.

[0148] Similar to what was described above with reference to FIG. 7, because the anchor UE transmits to or receives from the target UE via the sidelink, the link quality of the sidelink may also affect the positioning of the target UE. For example, a noisy sidelink may prevent the PRS from being received or decoded. The selection may be based on the link quality of the sidelink between the target UE and the candidate anchor UE. The candidate anchor UE or the target UE may determine a link quality metric for the sidelink (SINR, SNR, RSRP, etc.), and the link quality metric for the sidelink may be taken into account for the selection. For example, a candidate anchor UE may be eliminated if its SNR for the sidelink is below an SNR threshold. Using the link quality metric for selection may be performed in any suitable manner, such as any of the methods described above for measurement quality metrics or mobility states.

[0149] In some implementations, when a device selects a candidate anchor UE to be used as an anchor UE for positioning, the device may indicate the selection to the anchor UE, and the anchor UE may be configured to transmit a PRS to or receive a PRS from the target UE. For example, in UE-assisted positioning, the location server 172 may indicate the selection to one or more base stations (e.g., gNBs), which may indicate the selection to a suitable UE to be used as an anchor. This indication may also be provided to the target UE. In UE-based positioning, the target UE may indicate its selection to each anchor UE via a respective sidelink.

[0150] Although method 800 is shown as being performed for one selection or refinement for clarity in describing aspects of the present disclosure, a device may be configured to perform the selection or refinement multiple times. For example, the anchor UE's motion may be less than a threshold before time Q, but the anchor UE's motion may be greater than the threshold after time Q. As a result, the anchor UE may no longer be suitable for positioning. In some implementations, an anchor UE candidate may periodically provide its mobility state to a device. In this manner, the device may periodically determine whether the anchor UE candidate should remain an anchor UE or should remain excluded from being an anchor UE (e.g., based on one or more thresholds, variations, etc., as described above), and which anchor UE is used may be adjusted over time. In some implementations, providing the mobility state by an anchor UE candidate is based on a trigger. For example, if the mobility state is greater than a mobility threshold (e.g., speed is greater than a speed threshold), the anchor UE candidate may provide the mobility state to the device. In this way, anchor UE candidates may save power by not reporting their mobility state to the device when the mobility state has not changed by more than a threshold since the last report. While the above describes reporting the mobility state periodically or based on a trigger, providing the mobility state may refer to the anchor UE candidate providing location measurements or other information (e.g., RSTD), and the device itself determining the mobility state of the anchor UE candidate based on the location measurements or other information. Additionally or alternatively, the anchor UE candidate may indicate a change in link quality metric greater than a threshold or a link quality metric falling below a threshold. Based on the change in mobility state and / or the change in link quality metric, the device may again narrow down the anchor UE candidates or select an anchor UE for positioning. In this way, which anchor UE is used for positioning may be adjusted over time.

[0151] As noted above, method 700 of Figure 7 relates to location measurement of candidate anchor UEs, and method 800 of Figure 8 relates to mobility states of candidate anchor UEs. Additionally or alternatively, which anchor UE should be used for positioning of the target UE may be based on the GDOP associated with the candidate anchor UE.

[0152] In positioning, the geometry of the target UE and TRP affects the accuracy or potential error of the target UE's location estimate. For example, based on the resolution and timing of the PRS, the UE's location may be within a certain distance range from the TRP. For multiple TRPs, the UE's location may be within the intersection of the distance ranges of the multiple TRPs. The intersection of the ranges is the UE's location uncertainty when using multiple TRPs for positioning. Adjusting the TRP's location may adjust the shape and magnitude of the location uncertainty, which may affect the accuracy in determining the UE's location.

[0153] 9A is a diagram 900 illustrating a UE location uncertainty 910A associated with two TRPs 902 and 904 for positioning. Based on the timing and timing resolution of the PRSs, the UE's location may be determined to be within a range 906 of the TRP 902. Similarly, based on the timing and timing resolution of the PRSs, the UE's location may be determined to be within a range 908 of the TRP 904. In this manner, the UE may be located within the intersection of the two ranges 906 and 908, shown as location uncertainty 910A. The locations of the TRPs 902 and 904 affect the size and magnitude of the location uncertainty 910A. Also, although not shown, the number of TRPs to be used may affect the size and magnitude of the location uncertainty 910A.

[0154] FIG. 9B is a diagram 901 illustrating a location uncertainty 910B for a UE associated with two TRPs 902 and 904 for positioning. Compared to diagram 900, the positions of TRPs 902 and 904 relative to each other are different. As a result, ranges 906 and 908 in diagram 901 are associated with location uncertainty 910B. The magnitude of location uncertainty 910B is greater than the magnitude of location uncertainty 910A, and the UE is located somewhere within the respective location uncertainties. As a result, the possible error in the position estimation for the UE is greater in the topology of TRPs in diagram 901 than in the topology of TRPs in diagram 900. The intersection of ranges (such as location uncertainties 910A or 910B) may be referred to herein as a GDOP. The GDOP may be calculated in any suitable manner based on the type of positioning method used (such as TOA-based positioning).

[0155] In some implementations, the group of anchor UE candidates may be selected or narrowed down based on the GDOP associated with one or more anchor UE candidates. For example, some anchor UE candidates may be excluded from being anchors to reduce the size of the GDOP, or some anchor UE candidates may be selected as anchors, which may increase the accuracy or precision of the target UE's location estimate.

[0156] 10 shows a flowchart of an example method 1000 for selecting an anchor UE for positioning of a target UE in a wireless network. The example method 1000 may be performed by any appropriate device of a wireless network, such as the target UE 104 or the location server 172 shown in FIG. 1 , in a manner consistent with the disclosed implementations. For example, the method 1000 may be performed by the target UE 104 for UE-based positioning or by the location server 172 for UE-assisted positioning. A device that may perform one or more operations of the method 1000 may include at least one transceiver (such as one or more wireless transceivers and / or one or more wired transceivers), at least one memory, and at least one processor coupled to the at least one transceiver and the at least one memory. Referring to UE 300 as an exemplary device, the at least one transceiver may include transceiver 315 or wireless transceiver 340, the at least one memory may include memory 311, and the at least one processor may include one or more of processors 310, one or more of processors 330 through 334, or location device 319. Referring to base station 400 as an exemplary device, the at least one transceiver may include all or a portion of transceiver 415, the at least one memory may include memory 411, and the at least one processor may include processor 410. Referring to server 500 (e.g., location server) as an exemplary device, the at least one transceiver may include all or a portion of transceiver 515, the at least one memory may include memory 511, and the at least one processor may include processor 510.

[0157] At 1002, a device may obtain information related to multiple GDOPs, each GDOP determined for a different combination of anchor UE candidates for a target UE from multiple anchor UE candidates. The means for obtaining the information may include at least one transceiver of the device. In some implementations, the target UE may determine each GDOP. For example, multiple anchor UE candidates are within range and capable of communicating with the target UE via a sidelink. The target UE may select a first subset of the anchor UE candidates and estimate a first GDOP for the first subset, select a second subset of the anchor UE candidates and estimate a second GDOP for the second subset, etc. Any appropriate number of anchor UE candidates may be selected for each subset (e.g., three or more), and any appropriate number of subsets may be selected. For example, the target UE may be able to identify the best subset of anchor UE candidates for positioning of the target UE (e.g., the subset associated with the smallest GDOP), but may limit the number of subsets and / or the number of UEs to a minimum and / or maximum number to balance processing resources and time in estimating the GDOP.

[0158] Determining (e.g., estimating) GDOP may be performed in any suitable manner. For example, the target UE may use any conventional statistical method to estimate GDOP. Additionally, or instead, the target UE may use one or more machine learning models to estimate GDOP. Inputs to the one or more machine learning models may include RSTD measured by the anchor UE candidates, other location measurements by the anchor UE candidates, signal quality measures, mobility conditions, etc. In some implementations, data from base stations may be used as training data to train the machine learning model to estimate GDOP. The locations of the base stations may be known and used to determine known GDOPs associated with different subsets of base stations. The known GDOPs may be compared to estimated GDOPs that are used as feedback in training the machine learning model. Once the machine learning model is trained, it may be used to estimate GDOPs for a subset of anchor UE candidates whose locations may be unknown or less accurate than the known locations of the base stations. For ease of understanding when describing aspects of the present disclosure, the above examples describe a target UE as determining GDOP, however, any suitable device may determine one or more GDOPs (e.g., a base station, a neighboring UE, a candidate anchor UE, or another suitable network entity).

[0159] At 1004, the device may select one or more anchor UEs for positioning of the target UE from a plurality of anchor UE candidates. The means for selecting one or more anchor UEs may include at least one processor of the device. The selection is based on information related to a plurality of GDOPs. As described above, the target UE may determine GDOPs for different subsets of the anchor UE candidates. In UE-based positioning, the target UE may select an anchor UE from the anchor UE candidates based on the determined GDOPs. In this manner, the information related to the plurality of GDOPs may be the GDOPs themselves. For example, the target UE may compare the GDOPs to determine the smallest GDOP, and the target UE may select the anchor UE candidate used for the smallest GDOP as the anchor UE to be used for positioning.

[0160] In UE-assisted positioning, the location server 172 may select an anchor UE from anchor UE candidates. In some implementations, the information related to the multiple GDOPs may be the GDOPs themselves. In this manner, multiple GDOPs may be provided to a base station (e.g., a gNB) or a relay UE (e.g., by the target UE) between the target UE and a base station (e.g., a gNB), and the GDOPs are relayed to the location server 172 (e.g., through the gNB and / or the core network 170). Indicating the GDOPs may include indicating anchor UE candidates associated with each GDOP. In this manner, the location server 172 may obtain the GDOPs from the base station, and the location server 172 may select one or more anchor UEs from the anchor UE candidates based on the multiple GDOPs obtained from the base station.

[0161] The target UE may indicate all or only a portion of the GDOPs and associated anchor UE candidates as determined by the target UE. For example, the target UE may filter out GDOPs larger than a threshold size. In another example, the target UE may filter out GDOPs associated with specific anchor UE candidates (e.g., based on the measurement quality of the location measurement results or the mobility state of the anchor UE candidates). In this way, the target UE may narrow down the group of anchor UE candidates before location server 172 selects an anchor UE candidate from that group.

[0162] Additionally, or instead of indicating a GDOP, the target UE may determine one or more preferred anchor UEs from multiple anchor UE candidates based on multiple GDOPs, and the target UE may indicate one or more preferred anchor UEs. In this manner, information related to multiple GDOPs may include an indication of one or more preferred anchor UEs. For example, the target UE may determine one or more preferred anchor UEs as one or more anchor UE candidates associated with a particular GDOP (such as one or more minimum GDOPs estimated by the target UE) or a GDOP less than a threshold GDOP size. When indicating a preferred anchor UE instead of a GDOP and associated anchor UE candidates for each GDOP, this indication may reduce signaling requirements compared to indicating a GDOP. The target UE may indicate one or more preferred anchor UEs to a base station serving the target UE or to a relay UE between the base station and the target UE (this indication is provided to the base station), and location server 172 may obtain an indication of one or more preferred anchor UEs from a base station (e.g., via core network 170). In some implementations, the indication may include an indication of a ranking or order of the preferred anchor UEs. The location server 172 may select one or more anchor UEs based on the indication of the one or more preferred anchor UEs.

[0163] Although method 1000 is described above with reference to a single target UE, the selection of an anchor UE for positioning a target UE may be based on the selection of anchor UEs for positioning one or more UEs other than the target UE. The location server 172 may support UE-assisted positioning for multiple target UEs. In this manner, a TRP may be used for positioning multiple target UEs. If the location server 172 determines an anchor UE for each target UE independently of the anchor UEs determined for other target UEs, multiple UEs may be selected as anchors, resulting in more UEs than may be needed or desired consuming resources when acting as TRPs for positioning. The selection of an anchor UE for a first target UE may take into account the selection of anchor UEs for a second or other target UEs. For example, if the location server 172 obtains an indication of a preferred anchor UE for a target UE, the location server 172 may compare the preferred anchor UEs across multiple target UEs to determine a subset of anchor UEs to support positioning for all of the target UEs. A preferred anchor UE may be indicated for a target UE, but the preferred anchor UE may be excluded based on not being a preferred anchor UE for other target UEs. Although several examples are given above to illustrate some aspects of the present disclosure, any suitable manner in determining an anchor UE to be used for positioning of multiple target UEs may be implemented.

[0164] Similar to what was described above with reference to Figures 7 and 8, because the anchor UE transmits to or receives from the target UE via the sidelink, the link quality of the sidelink may also affect the positioning of the target UE. For example, a noisy sidelink may prevent the PRS from being received or decoded. The selection of an anchor UE may be based on the link quality of the sidelink between the target UE and the candidate anchor UE. The candidate anchor UE or the target UE may determine a link quality metric for the sidelink (SINR, SNR, RSRP, etc.), which may be taken into account for the narrowing down or selection. For example, a candidate anchor UE may be eliminated if its sidelink SNR is below an SNR threshold. Using the link quality metric for narrowing down or selection may be performed in any suitable manner, such as a measurement quality metric, mobility state, or any of the methods described above for GDOP.

[0165] In some implementations, the device may indicate the selection to the selected anchor UE, and the anchor UE may be configured to transmit the PRS to or receive the PRS from the target UE. For example, in UE-assisted positioning, the location server 172 may indicate the selection to one or more base stations (e.g., gNBs), which may indicate the selection to appropriate UEs to be used as anchors. This indication may also be provided to the target UE. In UE-based positioning, the target UE may indicate its selection to each anchor UE via a respective sidelink.

[0166] Although method 1000 is shown as being performed for a single selection of one or more anchor UEs for clarity in describing aspects of the present disclosure, a device may be configured to perform the selection multiple times. For example, the GDOP may change based on movement of the anchor UE. The location server or target UE (or another appropriate device) may determine that the GDOP should change based on periodically estimating the GDOP over time (e.g., based on new location measurements or other input from the anchor UE) or based on a trigger related to location measurements or the mobility state of the anchor UE. As a result, the anchor UE may no longer be suitable for positioning the target UE. In this manner, the device may periodically determine whether a candidate anchor UE should remain an anchor UE or whether it should remain excluded from being an anchor UE (e.g., based on one or more thresholds, variations, etc., as described above), and which anchor UEs are used may be adjusted over time. For example, a new GDOP may be determined, and one or more new anchor UEs may be selected for positioning based on information related to the new GDOP. Additionally or alternatively, in UE-assisted positioning, if the number of target UEs or the target UEs themselves change, the location server may again perform method 1000 to select one or more anchor UEs. Selecting one or more anchor UEs may be periodic or based on a trigger in any suitable manner.

[0167] 7, 8, and 10 describe selection or refinement based on measurement quality of location measurements, mobility state, or GDOP, respectively, which are unrelated to one another. However, selection or refinement may be based on any combination of measurement quality of location measurements, mobility state, or GDOP (or optionally, a link quality metric for the sidelink). In this manner, one or more devices of the wireless network (e.g., location server 172 or target UE) may perform one or more operations of one or more of methods 700, 800, or 1000. For example, selection of an anchor UE may be based on mobility states of the anchor UE candidates and GDOPs associated with the anchor UE candidates, and refinement of anchor UE candidates may be based on measurement quality metrics of location measurements of the anchor UE candidates and mobility states of the anchor UE candidates, etc.

[0168] 11 shows a flowchart of an example method for selecting an anchor UE for positioning of a target UE in a wireless network. The example method 1100 may be performed by any appropriate device of a wireless network, such as the target UE 104 or the location server 172 shown in FIG. 1, in a manner consistent with the disclosed implementations. For example, the method 1100 may be performed by the target UE 104 for UE-based positioning or by the location server 172 for UE-assisted positioning. A device that may perform one or more operations of the method 1100 may include at least one transceiver (such as one or more wireless transceivers and / or one or more wired transceivers), at least one memory, and at least one processor coupled to the at least one transceiver and the at least one memory. Referring to UE 300 as an exemplary device, the at least one transceiver may include transceiver 315 or wireless transceiver 340, the at least one memory may include memory 311, and the at least one processor may include one or more of processors 310, one or more of processors 330-334, or location device 319. Referring to base station 400 as an exemplary device, the at least one transceiver may include all or a portion of transceiver 415, the at least one memory may include memory 411, and the at least one processor may include processor 410. Referring to server 500 (e.g., a location server) as an exemplary device, the at least one transceiver may include all or a portion of transceiver 515, the at least one memory may include memory 511, and the at least one processor may include processor 510.

[0169] At 1102, a device acquires information related to one or more of location measurements and measurement quality metrics from one or more anchor UE candidates, mobility states of the one or more anchor UE candidates, or GDOPs associated with the one or more anchor UE candidates. The means for acquiring information may include one or more of at least one transceiver, at least one memory, or at least one processor of the device. As mentioned above, selecting at least one anchor UE candidate may be based on location measurements and measurement quality metrics associated with the anchor UE candidates (such as those described above in connection with FIG. 7), mobility states of the anchor UE candidates (such as those described above in connection with FIG. 8), information related to GDOPs for different combinations of anchor UE candidates for the target UE (such as those described above in connection with FIG. 10), or any combination of the above. In this manner, the device may perform one or more of optional steps 1104-1108 to perform step 1102.

[0170] In some implementations, the device may obtain, from one or more of the plurality of anchor UE candidates, one or more location measurements of the anchor UE candidates and a measurement quality metric for each of the one or more location measurements (1104). The means for obtaining the one or more location measurements and the measurement quality metric for each of the one or more location measurements may include at least one transceiver of the device. Optional step 1104 may be the same as step 702 of FIG. 7 described above.

[0171] In some implementations, the device may acquire, for one or more of the plurality of anchor UE candidates, mobility state of the anchor UE candidates (1106). The means for acquiring the mobility state may include one or more of at least one transceiver, at least one memory, or at least one processor of the device. Optional step 1106 may be the same as step 802 of FIG. 8 described above.

[0172] In some implementations, the device may obtain information related to multiple GDOPs, each GDOP determined for a different combination of anchor UE candidates for the target UE from multiple anchor UE candidates (1108). The means for obtaining the information may include at least one transceiver of the device. Optional step 1108 may be the same as step 1002 of FIG. 10 described above.

[0173] At 1110, the device selects at least one anchor UE candidate from multiple anchor UE candidates for positioning of the target UE based on the acquired information. The means for selecting at least one anchor UE candidate may include at least one processor of the device. For example, the location server or at least one processor of the target UE may be configured to select at least one anchor UE candidate (e.g., narrowing down multiple anchor UE candidates or selecting one or more anchor UE candidates as anchors) based on one or more of the acquired one or more location measurement results and measurement quality metrics of the one or more anchor UE candidates, the acquired mobility states of the one or more anchor UE candidates, or information related to multiple GDOPs for different combinations of anchor UE candidates for the target UE. To perform step 1110, the device may perform some or all of the operations described herein for one or more of step 704 of FIG. 7 described above, step 804 of FIG. 8 described above, or step 1004 of FIG. 10 described above.

[0174] References throughout this specification to "one example," "an example," "some examples," or "exemplary implementations" mean that a particular feature, structure, or characteristic described with respect to a feature and / or example may be included in at least one feature and / or example of the claimed subject matter. Thus, the appearances of the phrases "in one example," "an example," "some examples," or "in some implementations" or other similar phrases in various places throughout this specification are not necessarily all referring to the same features, examples, and / or limitations. Furthermore, particular features, structures, or characteristics may be combined in one or more examples and / or characteristics.

[0175] Some portions of the detailed descriptions contained herein are presented in terms of algorithms or symbolic representations of operations on binary digital signals stored in a memory of a particular apparatus or special purpose computing device or platform. In the context of this particular specification, the term particular apparatus or the like includes a general purpose computer that, when programmed, performs particular operations pursuant to instructions from program software. Algorithmic descriptions or symbolic representations are examples of techniques used by those skilled in the signal processing or related arts to convey the substance of their work to others skilled in the art. An algorithm, as used herein, and generally, is considered to be a self-consistent sequence of operations or similar signal processing leading to a desired result. In this context, operations or processing involve physical manipulations of physical quantities. Usually, though not necessarily, such quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to such signals as bits, data, values, elements, symbols, characters, terms, numbers, numeric values, or the like. It should be understood, however, that all of these or similar terms are to be associated with the appropriate physical quantities and are merely convenient labels. Unless otherwise expressly indicated, and as will be apparent from the description herein, it will be understood that throughout this specification, descriptions utilizing terms such as "processing," "computing," "calculating," "determining," etc. refer to the actions or processes of a particular apparatus, such as a special purpose computer, a special purpose computing apparatus, or a similar special purpose electronic computing device. Thus, in the context of this specification, a special purpose computer or similar special purpose electronic computing device is capable of manipulating or transforming signals, which are typically represented as physical electronic or magnetic quantities in a memory, register, or other information storage, transmission, or display device of the special purpose computer or similar special purpose electronic computing device.

[0176] In the foregoing detailed description, numerous specific details are set forth to provide a thorough understanding of the claimed subject matter. However, it will be understood by those skilled in the art that the claimed subject matter may be practiced without these specific details. In other instances, methods and apparatuses that would be known by those skilled in the art have not been described in detail so as not to obscure the claimed subject matter.

[0177] As used herein, the terms "and," "or," and "and / or" can have a variety of meanings, which are also expected to depend, at least in part, on the context in which such terms are used. Typically, when "or" is used to link a list such as A, B, or C, it is intended to mean A, B, and C, which is used herein in an inclusive sense, as well as A, B, or C, which is used herein in an exclusive sense. Additionally, as used herein, the term "one or more" may be used to describe any feature, structure, or characteristic in singular, or it may be used to describe a plurality of features, structures, or characteristics, or some other combination of features, structures, or characteristics. However, it should be noted that this is merely an illustrative example, and claimed subject matter is not limited to this example.

[0178] While what are presently considered to be exemplary features have been illustrated and described, it will be understood by those skilled in the art that various other modifications may be made and equivalents may be substituted without departing from the claimed subject matter. Additionally, many modifications may be made to adapt a particular situation to the teachings of the claimed subject matter without departing from the central concept described herein.

[0179] Example implementations are described in the following numbered clauses. 1. A method for selecting an anchor user equipment (UE) for positioning of a target user equipment (UE) in a wireless network, comprising: obtaining, from one or more of a plurality of anchor UE candidates, one or more location measurements of the anchor UE candidates and a measurement quality metric for each of the one or more location measurements; and selecting at least one anchor UE candidate from the plurality of anchor UE candidates for positioning of the target UE based on one or more measurement quality metrics from the one or more anchor UE candidates. 2. The method of clause 1, wherein obtaining one or more location measurement results and measurement quality measures for the anchor UE candidate includes obtaining one or more location measurement results and measurement quality measures for the anchor UE candidate in one or more NR-based positioning-related measurement reports from the anchor UE candidate. 3. One or more methods of clauses 1 to 2, wherein the one or more location measurements include one or more reference signal time differences (RSTDs) measured by the candidate anchor UE using positioning reference signal (PRS) resources obtained from one or more devices in the wireless network. 4. UE-based positioning is performed by the target UE; 4. The method of claim 1, wherein one or more positioning-related measurement reports are obtained by the target UE from the anchor UE candidate via a side link (SL) between the target UE and the anchor UE candidate. 5. The method of one or more of clauses 1 to 4, further comprising providing, by the target UE, one or more of the PRS resources to the candidate anchor UE via the SL. 6. UE-assisted positioning for the target UE is to be performed by a location server of the wireless network; One or more of the PRS resources are provided by the base station on a downlink (DL) to the anchor UE candidate; one or more positioning-related measurement reports are provided from the candidate anchor UE to the base station; one or more location measurement results and measurement quality metrics from one or more positioning-related measurement reports are provided from the base station to a location server; 4. The method of claim 1, wherein the step of selecting at least one anchor UE candidate comprises the step of the location server selecting the anchor UE candidate as the anchor UE based on one or more location measurement results and measurement quality metrics. 7. The method of clause 1, wherein, for one or more anchor UE candidates, each location measurement result and associated measurement quality metric is radio access technology (RAT) independent. 8. One or more methods of clauses 1 to 7, wherein each location measurement result and associated measurement quality measure is determined by the anchor UE candidate using a Global Navigation Satellite System (GNSS). 9. UE-based positioning is to be performed by the target UE; 8. The method of one or more of clauses 1 to 7, wherein one or more location measurement results and measurement quality measures of the anchor UE candidate are obtained from the anchor UE candidate via a side link (SL) between the target UE and the anchor UE candidate. 10. UE-assisted positioning of the target UE is performed by a location server of the wireless network; one or more location measurements and measurement quality metrics are provided from the candidate anchor UE to the base station; one or more location measurements and measurement quality measures are provided from the base station to a location server; 8. The method of claim 1, wherein the step of selecting at least one anchor UE candidate comprises the step of the location server selecting the anchor UE candidate as the anchor UE based on one or more location measurement results and measurement quality metrics. 11. The method of clause 1, further comprising determining a variance in the measurement quality metric for a plurality of anchor UE candidates, wherein selecting at least one anchor UE candidate is based on the determined variance. 12. One or more methods of clauses 1 to 11, in which the variability includes the mean and variance of the measurement quality measure. 13. The method of clause 1, wherein selecting at least one anchor UE candidate is also based on link quality of a side link (SL) between the target UE and one or more anchor UE candidates. 14. A device configured to select an anchor user equipment (UE) for positioning of a target user equipment (UE) in a wireless network, comprising: at least one transceiver; at least one memory; at least one processor coupled to the at least one transceiver and the at least one memory, the at least one processor causing the device to: obtaining one or more location measurements of the anchor UE candidates and a measurement quality metric for each of the one or more location measurements from one or more of the plurality of anchor UE candidates via the at least one transceiver; A device configured to cause, via at least one processor, selection of at least one anchor UE candidate from a plurality of anchor UE candidates for positioning of a target UE based on one or more measurement quality metrics from the one or more anchor UE candidates. 15. The device of clause 14, wherein to obtain one or more location measurement results and measurement quality measures for the anchor UE candidate, the at least one processor is configured to cause the device to obtain one or more location measurement results and measurement quality measures for the anchor UE candidate in one or more NR-based positioning-related measurement reports from the anchor UE candidate. 16. One or more devices of clauses 14 to 15, wherein the one or more location measurements include one or more reference signal time differences (RSTDs) measured by the anchor UE candidate using positioning reference signal (PRS) resources obtained from one or more devices in the wireless network. 17. UE-based positioning is configured to be performed by a target UE; 17. The one or more devices of clauses 14 to 16, wherein at least one processor is configured to cause the device to obtain, via the at least one transceiver, one or more positioning-related measurement reports from the anchor UE candidate via a side link (SL) between the target UE and the anchor UE candidate. 18. One or more devices of clauses 14 to 17, wherein at least one processor is configured to cause the device, via at least one transceiver, to provide one or more of the PRS resources over the SL to a candidate anchor UE, and the device is a target UE. 19. The device is a location server of a wireless network configured to perform UE-assisted positioning for a target UE; One or more of the PRS resources will be provided by the base station on the downlink (DL) to the anchor UE candidate; one or more positioning-related measurement reports are to be provided by the anchor UE candidate to the base station; one or more location measurement results and measurement quality measures from one or more positioning-related measurement reports are to be provided from the base station to the location server; 17. The one or more devices of clauses 14 to 16, wherein, to select the at least one anchor UE candidate, the at least one processor is configured to cause the device, via the at least one processor, to select the anchor UE candidate as the anchor UE based on the one or more location measurement results and measurement quality measures. 20. The device of clause 14, wherein, for one or more anchor UE candidates, each location measurement result and associated measurement quality metric is radio access technology (RAT) independent. 21. One or more devices of clauses 14 to 20, wherein each location measurement result and associated measurement quality measure is to be determined by the anchor UE candidate using a Global Navigation Satellite System (GNSS). 22. The device is a target UE configured to perform UE-based positioning; 21. The one or more devices of clauses 14 to 20, wherein at least one processor is configured to cause the device to obtain, via the at least one transceiver, one or more location measurements and measurement quality measures of the anchor UE candidate from the anchor UE candidate via a side link (SL) between the target UE and the anchor UE candidate. 23. The device is a location server of a wireless network configured to perform UE-assisted positioning of a target UE; one or more location measurements and measurement quality measures are to be provided from the candidate anchor UE to the base station; one or more location measurements and measurement quality measures are to be provided from the base station to the location server; 21. The one or more devices of clauses 14 to 20, wherein, to select the at least one anchor UE candidate, the at least one processor is configured to cause the device, via the at least one processor, to select the anchor UE candidate as the anchor UE based on the one or more location measurement results and measurement quality measures. 24. The device of clause 14, wherein the at least one processor is configured to cause the device, via the at least one processor, to determine a variance in the measurement quality measure for a plurality of anchor UE candidates, and based on the determined variance select at least one anchor UE candidate. 25. One or more devices of clauses 14 to 24, in which the variability includes the mean and variance of the measurement quality measure. 26. The device of clause 14, wherein selecting at least one anchor UE candidate is also based on link quality of a side link (SL) between the target UE and one or more anchor UE candidates. 27. A non-transitory computer-readable medium storing instructions, the instructions, when executed by at least one processor of a device configured to select an anchor UE for positioning of a target user equipment (UE) in a wireless network, causing the device to: obtaining one or more location measurements of the anchor UE candidates and a measurement quality metric for each of the one or more location measurements from one or more of the plurality of anchor UE candidates via the at least one transceiver; A non-transitory computer-readable medium that causes, via at least one processor, selection of at least one anchor UE candidate from a plurality of anchor UE candidates for positioning of a target UE based on one or more measurement quality metrics from the one or more anchor UE candidates. 28. The computer-readable medium of clause 27, wherein execution of the instructions causes the device, upon obtaining one or more location measurement results and measurement quality measures for the anchor UE candidate, to obtain one or more location measurement results and measurement quality measures for the anchor UE candidate in one or more NR-based positioning-related measurement reports from the anchor UE candidate. 29. The computer-readable medium of one or more of clauses 27-28, wherein the one or more location measurements include one or more reference signal time differences (RSTDs) measured by the anchor UE candidate using positioning reference signal (PRS) resources obtained from one or more devices in the wireless network. 30. UE-based positioning is configured to be performed by a target UE; 30. The computer-readable medium of one or more of clauses 27 to 29, wherein execution of the instructions causes the device to obtain, via at least one transceiver, one or more positioning-related measurement reports from the anchor UE candidate via a side link (SL) between the target UE and the anchor UE candidate. 31. The computer-readable medium of one or more of clauses 27-30, wherein execution of the instructions causes the device to provide, via at least one transceiver, one or more of the PRS resources over the SL to a candidate anchor UE, and the device is a target UE. 32. The device is a location server of a wireless network configured to perform UE-assisted positioning for a target UE; One or more of the PRS resources will be provided by the base station on the downlink (DL) to the anchor UE candidate; one or more positioning-related measurement reports are to be provided by the anchor UE candidate to the base station; one or more location measurement results and measurement quality measures from one or more positioning-related measurement reports are to be provided from the base station to the location server; 30. The computer-readable medium of one or more of clauses 27 to 29, wherein execution of the instructions causes the device, via the at least one processor, in selecting the at least one anchor UE candidate, to select the anchor UE candidate as the anchor UE based on one or more location measurement results and measurement quality measures. 33. The computer-readable medium of clause 27, wherein, for one or more anchor UE candidates, each location measurement result and associated measurement quality metric is radio access technology (RAT) independent. 34. The computer-readable medium or media of clauses 27 to 33, wherein each location measurement result and associated measurement quality measure is determined by the anchor UE candidate using a Global Navigation Satellite System (GNSS). 35. The device is a target UE configured to perform UE-based positioning; 34. The computer-readable medium of one or more of clauses 27 to 33, wherein execution of the instructions causes the device to obtain, via at least one transceiver, one or more location measurements and measurement quality measures of the anchor UE candidate from the anchor UE candidate via a side link (SL) between the target UE and the anchor UE candidate. 36. The device is a location server of a wireless network configured to perform UE-assisted positioning of a target UE; one or more location measurements and measurement quality measures are to be provided from the candidate anchor UE to the base station; one or more location measurements and measurement quality measures are to be provided from the base station to the location server; 34. The one or more computer-readable media of clauses 27-33, wherein execution of the instructions causes the device, via the at least one processor, in selecting the at least one anchor UE candidate, to select the anchor UE candidate as the anchor UE based on one or more location measurement results and measurement quality measures. 37. The computer-readable medium of clause 27, wherein execution of the instructions causes the device, via the at least one processor, to determine a variance in the measurement quality metric for a plurality of anchor UE candidates and select at least one anchor UE candidate based on the determined variance. 38. The computer-readable medium of one or more of clauses 27 to 37, wherein the variability includes the mean and variance of the measurement quality measure. 39. The computer-readable medium of clause 27, wherein selecting at least one anchor UE candidate is also based on link quality of a side link (SL) between the target UE and one or more anchor UE candidates. 40. A device for selecting an anchor user equipment (UE) for positioning of a target user equipment (UE) in a wireless network, comprising: means for obtaining, from one or more of a plurality of anchor UE candidates, one or more location measurements of the anchor UE candidates and a measurement quality metric for each of the one or more location measurements; and means for selecting at least one anchor UE candidate from a plurality of anchor UE candidates for positioning of the target UE based on one or more measurement quality metrics from the one or more anchor UE candidates. 41. The device of clause 40, wherein the means for obtaining one or more location measurement results and measurement quality measures for the candidate anchor UE comprises means for obtaining one or more location measurement results and measurement quality measures for the candidate anchor UE in one or more NR-based positioning-related measurement reports from the candidate anchor UE. 42. One or more devices of clauses 40 to 41, wherein the one or more location measurements include one or more reference signal time differences (RSTDs) measured by the anchor UE candidate using positioning reference signal (PRS) resources obtained from one or more devices in the wireless network. 43. UE-based positioning is to be performed by the target UE; The one or more devices of clauses 40 to 42, wherein one or more positioning-related measurement reports are obtained by the target UE from the anchor UE candidate via a side link (SL) between the target UE and the anchor UE candidate. 44. The device or devices of clauses 40 to 43, further including means for providing, by the target UE, one or more of the PRS resources to the candidate anchor UE via the SL. 45. UE-assisted positioning for the target UE is to be performed by a location server of the wireless network; One or more of the PRS resources will be provided by the base station on the downlink (DL) to the anchor UE candidate; one or more positioning-related measurement reports are to be provided from the candidate anchor UE to the base station; one or more location measurement results and measurement quality measures from one or more positioning-related measurement reports are to be provided from the base station to the location server; 43. The one or more devices of clauses 40 to 42, wherein the means for selecting at least one anchor UE candidate comprises means in the location server for selecting the anchor UE candidate as the anchor UE based on one or more location measurement results and measurement quality measures. 46. ​​The device of clause 40, wherein, for one or more anchor UE candidates, each location measurement result and associated measurement quality metric is radio access technology (RAT) independent. 47. One or more devices of clauses 40 to 46, wherein each location measurement result and associated measurement quality measure is to be determined by the anchor UE candidate using a Global Navigation Satellite System (GNSS). 48. UE-based positioning is to be performed by the target UE; 47. The one or more devices of clauses 40 to 46, wherein one or more location measurement results and measurement quality measures of the anchor UE candidate are obtained from the anchor UE candidate via a side link (SL) between the target UE and the anchor UE candidate. 49. UE-assisted positioning of the target UE is to be performed by a location server of the wireless network; one or more location measurements and measurement quality measures are to be provided from the candidate anchor UE to the base station; one or more location measurements and measurement quality measures are to be provided from the base station to the location server; 47. The one or more devices of clauses 40 to 46, wherein the means for selecting at least one anchor UE candidate comprises means in the location server for selecting the anchor UE candidate as the anchor UE based on one or more location measurement results and measurement quality measures. 50. The device of clause 40, further comprising means for determining a variance in the measurement quality measure for a plurality of anchor UE candidates, and selecting at least one anchor UE candidate based on the determined variance. 51. One or more devices of clauses 40 to 50, in which the variability includes the mean and variance of the measurement quality measure. 52. The device of clause 40, wherein selecting at least one anchor UE candidate is also based on link quality of a side link (SL) between the target UE and one or more anchor UE candidates. 53. A method for selecting an anchor user equipment (UE) for positioning of a target user equipment (UE) in a wireless network, comprising: obtaining, for one or more of the plurality of anchor UE candidates, a mobility state of the anchor UE candidate; selecting at least one anchor UE candidate from a plurality of anchor UE candidates for positioning of the target UE based on one or more mobility states. 54. The method of clause 53, wherein obtaining a mobility state of the anchor UE candidate includes obtaining the mobility state from the anchor UE candidate, the mobility state being determined by the anchor UE candidate. 55. One or more of the methods of clauses 53 to 54, wherein the mobility state determined by the anchor UE candidate is radio access technology (RAT) dependent. 56. The method of one or more of clauses 53 to 54, wherein the mobility state determined by the anchor UE candidate is independent of the radio access technology (RAT). 57. The method or methods of clauses 53 to 56, wherein the mobility state is determined by the anchor UE candidate using an inertial measurement unit (IMU). 58. One or more methods of clauses 53 to 54, wherein the mobility status is periodically provided by the anchor UE candidate. 59. The method of one or more of clauses 53-54, wherein the mobility state is provided by the anchor UE candidate when the mobility state is greater than a mobility threshold. 60. UE-based positioning is to be performed by the target UE; 55. The method of one or more of clauses 53 to 54, wherein the mobility state is obtained by the target UE from the anchor UE candidate via a side link (SL) between the target UE and the anchor UE candidate. 61. The method of clause 53, wherein obtaining a mobility state of the candidate anchor UE includes determining the mobility state from a location history of the candidate anchor UE. 62. UE-assisted positioning of the target UE is performed by a location server of the wireless network; 62. The method of one or more of clauses 53 to 61, wherein the location history of the candidate anchor UE is determined by the location server from one or more reports from the candidate anchor UE. 63. The method of clause 53, wherein the mobility state of the anchor UE candidate includes a speed of the anchor UE candidate. 64. A device configured to select an anchor user equipment (UE) for positioning of a target user equipment (UE) in a wireless network, comprising: at least one transceiver; at least one memory; and at least one processor coupled to the at least one transceiver and the at least one memory, the at least one processor causing the device to: obtaining, via one or more of the at least one transceiver or the at least one processor, anchor UE candidate mobility states for one or more of the plurality of anchor UE candidates; A device configured to cause, via at least one processor, selection of at least one anchor UE candidate from a plurality of anchor UE candidates for positioning of a target UE based on one or more mobility states. 65. The device of clause 64, wherein to obtain a mobility state of the anchor UE candidate, the at least one processor is configured to cause the device to obtain, via the at least one transceiver, the mobility state from the anchor UE candidate, wherein the mobility state is to be determined by the anchor UE candidate. 66. One or more devices of clauses 64 to 65, wherein the mobility state to be determined by the anchor UE candidate depends on the radio access technology (RAT). 67. One or more devices of clauses 64 to 65, wherein the mobility state to be determined by the anchor UE candidate is independent of the radio access technology (RAT). 68. One or more devices of clauses 64 to 67, wherein the mobility state is to be determined by the anchor UE candidate using an inertial measurement unit (IMU). 69. One or more devices of clauses 64 to 65, whose mobility state is to be periodically provided by a candidate anchor UE. 70. One or more devices of clauses 64 to 65, wherein the mobility state is to be served by the anchor UE candidate when the mobility state is greater than a mobility threshold. 71. The device is a target UE configured to perform UE-based positioning; 66. The one or more devices of clauses 64 to 65, wherein at least one processor is configured to cause the device to obtain, via the at least one transceiver, mobility state from the anchor UE candidate via a side link (SL) between the target UE and the anchor UE candidate. 72. The device of clause 64, wherein to obtain a mobility state of the anchor UE candidate, the at least one processor is configured to cause the device, via the at least one processor, to determine the mobility state from the location history of the anchor UE candidate. 73. A device is a location server of a wireless network configured to perform UE-assisted positioning of a target UE; 73. The one or more devices of clauses 64-72, wherein the at least one processor is configured to cause the device, via the at least one processor, to determine a location history of the anchor UE candidate from one or more reports from the anchor UE candidate. 74. The device of clause 64, wherein the mobility state of the anchor UE candidate includes a speed of the anchor UE candidate. 75. A non-transitory computer-readable medium storing instructions, the instructions, when executed by at least one processor of a device for selecting an anchor UE for positioning of a target user equipment (UE) in a wireless network, causing the device to: obtaining, via one or more of the at least one transceiver or the at least one processor, anchor UE candidate mobility states for one or more of the plurality of anchor UE candidates; A non-transitory computer-readable medium that causes, via at least one processor, selection of at least one anchor UE candidate from a plurality of anchor UE candidates for positioning of a target UE based on one or more mobility states. 76. The computer-readable medium of clause 75, wherein execution of the instructions causes the device, in obtaining mobility state of the anchor UE candidate, to obtain, via the at least one transceiver, mobility state from the anchor UE candidate, wherein the mobility state is determined by the anchor UE candidate. 77. The computer-readable medium of one or more of clauses 75 to 76, wherein the mobility state to be determined by the anchor UE candidate is radio access technology (RAT) dependent. 78. The computer-readable medium of one or more of clauses 75-76, wherein the mobility state to be determined by the anchor UE candidate is independent of the radio access technology (RAT). 79. The computer-readable medium of one or more of clauses 75 to 78, wherein the mobility state is to be determined by the anchor UE candidate using an inertial measurement unit (IMU). 80. The computer-readable medium of one or more of clauses 75-76, wherein the mobility state is to be periodically provided by the anchor UE candidate. 81. The computer-readable medium of one or more of clauses 75-76, wherein the mobility state is to be served by the anchor UE candidate when the mobility state is greater than a mobility threshold. 82. The device is a target UE configured to perform UE-based positioning; 77. The computer-readable medium of one or more of clauses 75 to 76, wherein execution of the instructions causes the device to obtain mobility state from the anchor UE candidate via a side link (SL) between the target UE and the anchor UE candidate via at least one transceiver. 83. The computer-readable medium of clause 75, wherein execution of the instructions causes the device, when obtaining mobility state of the anchor UE candidate, via the at least one processor, to obtain mobility state from the location history of the anchor UE candidate. 84. A device is a location server of a wireless network configured to perform UE-assisted positioning of a target UE; 84. The one or more computer-readable media of clauses 75-83, wherein execution of the instructions causes the device, via at least one processor, to determine location histories of candidate anchor UEs from one or more reports from the candidate anchor UEs. 85. The computer-readable medium of clause 75, wherein the mobility state of the anchor UE candidate includes a speed of the anchor UE candidate. 86. A device for selecting an anchor user equipment (UE) for positioning of a target user equipment (UE) in a wireless network, comprising: means for obtaining, for one or more of the plurality of anchor UE candidates, a mobility state of the anchor UE candidate; and means for selecting at least one anchor UE candidate from a plurality of anchor UE candidates for positioning of the target UE based on one or more mobility states. 87. The device of clause 86, wherein the means for obtaining a mobility state of the anchor UE candidate includes means for obtaining the mobility state from the anchor UE candidate, wherein the mobility state is to be determined by the anchor UE candidate. 88. One or more devices of clauses 86 to 87, wherein the mobility state to be determined by the anchor UE candidate depends on the radio access technology (RAT). 89. One or more devices of clauses 86 to 87, wherein the mobility state to be determined by the anchor UE candidate is independent of the radio access technology (RAT). 90. One or more devices of clauses 86 to 89, the mobility state of which is to be determined by the anchor UE candidate using an inertial measurement unit (IMU). 91. One or more devices of clauses 86 to 87, whose mobility state is to be periodically provided by a candidate anchor UE. 92. One or more devices of clauses 86 to 87, wherein the mobility state is to be served by the anchor UE candidate when the mobility state is greater than a mobility threshold. 93. UE-based positioning is to be performed by the target UE; 88. The one or more devices of clauses 86 to 87, wherein the mobility state is to be obtained by the target UE from the anchor UE candidate via a side link (SL) between the target UE and the anchor UE candidate. 94. The device or devices of clauses 86-86, wherein the means for obtaining a mobility state of the candidate anchor UE includes means for determining the mobility state from a location history of the candidate anchor UE. 95. UE-assisted positioning of the target UE is performed by a location server of the wireless network; The one or more devices of clauses 86 to 94, wherein the location history of the anchor UE candidate is determined by the location server from one or more reports from the anchor UE candidate. 96. The device of clause 86, wherein the mobility state of the anchor UE candidate includes a speed of the anchor UE candidate. 97. A method for selecting an anchor user equipment (UE) for positioning of a target user equipment (UE) in a wireless network, comprising: obtaining information related to a plurality of geometric dilutions of precision (GDOP), each GDOP being determined for a different combination of anchor UE candidates for a target UE from a plurality of anchor UE candidates; selecting one or more anchor UEs for positioning the target UE from a plurality of candidate anchor UEs, wherein the selection is based on the obtained information. 98. The method of clause 97, wherein the UE-assisted positioning is performed by a location server of the wireless network. 99. The step of obtaining information related to a plurality of GDOPs includes obtaining a plurality of GDOPs from a base station; Several G.D.O.P. the target UE, or Relay UE between the base station and the target UE obtained by the base station from one of The method of one or more of clauses 97-98, wherein the selection by the location server of one or more anchor UEs for positioning the target UE is based on a plurality of GDOPs obtained from the base station. 100. The step of obtaining information related to a plurality of GDOPs includes obtaining an indication of one or more preferred anchor UEs for the target UE from a base station; one or more preferred anchor UEs are determined by the target UE based on the plurality of GDOPs; An indication of one or more preferred anchor UEs base station, or Relay UE between the base station and the target UE provided by the target UE to one of 99. The method of one or more of clauses 97-98, wherein the selection by the location server of one or more anchor UEs for positioning the target UE is based on an indication of one or more preferred anchor UEs. 101. The method of one or more of clauses 97-98, wherein the location server's selection of one or more anchor UEs for positioning the target UE is also based on the selection of anchor UEs for positioning one or more UEs other than the target UE. 102. The method of clause 97, wherein obtaining information relating to a plurality of GDOPs includes determining, by the target UE, a plurality of GDOPs, and UE-based positioning is to be performed by the target UE. 103. A device configured to select an anchor user equipment (UE) for positioning of a target user equipment (UE) in a wireless network, comprising: at least one transceiver; at least one memory; and at least one processor coupled to the at least one transceiver and the at least one memory, the at least one processor causing the device to: acquiring, via one or more of the at least one transceiver or the at least one processor, information related to a plurality of geometric dilutions of precision (GDOPs), each GDOP determined for a different combination of anchor UE candidates for the target UE from a plurality of anchor UE candidates; selecting, via one or more of the at least one transceiver or the at least one processor, one or more anchor UEs for positioning the target UE from a plurality of anchor UE candidates, the selection being based on the acquired information; The device is configured to: 104. The device of clause 103, wherein the device is a location server of a wireless network configured to perform UE-assisted positioning. 105. To obtain information related to multiple GDOPs, at least one processor in the device: configured to acquire a plurality of GDOPs from a base station via at least one transceiver, the plurality of GDOPs comprising: the target UE, or Relay UE between the base station and the target UE The base station will receive the signal from one of the The device or devices of clauses 103-104, wherein the selection, via the at least one processor, of one or more anchor UEs for positioning of the target UE is based on a plurality of GDOPs obtained from the base station. 106. To obtain information related to multiple GDOPs, at least one processor in the device: configured to cause, via the at least one transceiver, to obtain from the base station an indication of one or more preferred anchor UEs for the target UE; One or more preferred anchor UEs are to be determined by the target UE based on the plurality of GDOPs; An indication of one or more preferred anchor UEs base station, or Relay UE between the base station and the target UE will be provided by the target UE to one of The device or devices of clauses 103-104, wherein the selection, via the at least one processor, of one or more anchor UEs for positioning of the target UE is based on an indication of one or more preferred anchor UEs. 107. The device or devices of clauses 103 to 104, wherein the selection of one or more anchor UEs for positioning of the target UE is also based on the selection of anchor UEs for positioning of one or more UEs other than the target UE. 108. The device of clause 103, wherein the device is a target UE configured to perform UE-based positioning, and wherein the at least one processor is configured to cause the device, via the at least one processor, to determine the plurality of GDOPs to obtain information related to the plurality of GDOPs. 109. A non-transitory computer-readable medium containing instructions, the instructions, when executed by at least one processor of a device configured to select an anchor UE for positioning of a target user equipment (UE) in a wireless network, causing the device to: acquiring, via one or more of the at least one transceiver or the at least one processor, information related to a plurality of geometric dilutions of precision (GDOPs), each GDOP determined for a different combination of anchor UE candidates for the target UE from a plurality of anchor UE candidates; A non-transitory computer-readable medium for selecting, via one or more of the at least one transceiver or the at least one processor, one or more anchor UEs for positioning of a target UE from a plurality of anchor UE candidates, the selection being based on the obtained information. 110. The computer-readable medium of clause 109, wherein the device is a location server of a wireless network configured to perform UE-assisted positioning. 111. Execution of the instruction causes a device to obtain information related to multiple GDOPs: Acquiring a plurality of GDOPs from a base station via at least one transceiver, the plurality of GDOPs comprising: the target UE, or Relay UE between the base station and the target UE The base station will receive the signal from one of the 111. The computer-readable medium of one or more of clauses 109-110, wherein selection, via at least one processor, of one or more anchor UEs for positioning of the target UE is based on a plurality of GDOPs obtained from the base station. 112. Execution of the instruction causes a device to obtain information related to multiple GDOPs: obtaining, via the at least one transceiver, an indication of one or more preferred anchor UEs for the target UE from a base station; One or more preferred anchor UEs are to be determined by the target UE based on the plurality of GDOPs; An indication of one or more preferred anchor UEs base station, or Relay UE between the base station and the target UE will be provided by the target UE to one of 111. The computer-readable medium of one or more of clauses 109-110, wherein the selection, via at least one processor, of one or more anchor UEs for positioning of the target UE is based on an indication of one or more preferred anchor UEs. 113. The computer-readable medium of one or more of clauses 109-110, wherein the selection of one or more anchor UEs for positioning of the target UE is also based on the selection of anchor UEs for positioning of one or more UEs other than the target UE. 114. The computer-readable medium of clause 109, wherein the device is a target UE configured to perform UE-based positioning, and execution of the instructions causes the device, via the at least one processor, to determine a plurality of GDOPs upon obtaining information related to the plurality of GDOPs. 115. A device for selecting an anchor user equipment (UE) for positioning of a target user equipment (UE) in a wireless network, comprising: means for acquiring information related to a plurality of geometric dilutions of precision (GDOP), each GDOP being determined for a different combination of anchor UE candidates for a target UE from a plurality of anchor UE candidates; and means for selecting one or more anchor UEs for positioning of the target UE from a plurality of candidate anchor UEs, the selection being based on the obtained information. 116. The device of clause 115, wherein the UE-assisted positioning is to be performed by a location server of the wireless network. 117. The means for obtaining information related to a plurality of GDOPs includes means for obtaining a plurality of GDOPs from a base station; Several G.D.O.P. the target UE, or Relay UE between the base station and the target UE The base station will receive the signal from one of the 117. The device or devices of clauses 115-116, wherein the selection by the location server of one or more anchor UEs for positioning the target UE is based on a plurality of GDOPs obtained from the base station. 118. The means for obtaining information related to a plurality of GDOPs includes means for obtaining an indication of one or more preferred anchor UEs for the target UE from a base station; One or more preferred anchor UEs are to be determined by the target UE based on the plurality of GDOPs; An indication of one or more preferred anchor UEs base station, or Relay UE between the base station and the target UE will be provided by the target UE to one of 117. The device or devices of clauses 115-116, wherein the selection by the location server of one or more anchor UEs for positioning the target UE is based on an indication of one or more preferred anchor UEs. 119. The device or devices of clauses 115 to 116, wherein the selection by the location server of one or more anchor UEs for positioning the target UE is also based on the selection of anchor UEs for positioning one or more UEs other than the target UE. 120. The device of clause 115, wherein the means for obtaining information relating to a plurality of GDOPs includes means for determining, by the target UE, a plurality of GDOPs, and wherein UE-based positioning is to be performed by the target UE. 121. A method for selecting an anchor user equipment (UE) for positioning of a target user equipment (UE) in a wireless network, comprising: location measurement results and measurement quality measures for one or more candidate anchor UEs; the mobility state of one or more anchor UE candidates, or Geometric Dilution of Precision (GDOP) associated with one or more anchor UE candidates obtaining information relating to one or more of: and selecting at least one anchor UE candidate from a plurality of anchor UE candidates for positioning of the target UE based on the obtained information. 122. The method of clause 121, wherein obtaining information includes obtaining, from one or more of the plurality of anchor UE candidates, one or more location measurements of the anchor UE candidates and a measurement quality metric for each of the one or more location measurements. 123. The method of one or more of clauses 121-122, wherein obtaining information includes obtaining anchor UE candidate mobility state for one or more of the plurality of anchor UE candidates. 124. The method of one or more of clauses 121-123, wherein obtaining information includes obtaining information related to a plurality of GDOPs, each GDOP determined for a different combination of anchor UE candidates for the target UE from a plurality of anchor UE candidates. 125. A device configured to select an anchor user equipment (UE) for positioning of a target user equipment (UE) in a wireless network, comprising: at least one transceiver; at least one memory; and at least one processor coupled to the at least one transceiver and the at least one memory, the at least one processor causing the device to: location measurement results and measurement quality measures for one or more candidate anchor UEs; the mobility state of one or more anchor UE candidates, or Geometric Dilution of Precision (GDOP) associated with one or more anchor UE candidates obtain information relating to one or more of the following: The device is configured to cause selection of at least one anchor UE candidate from a plurality of anchor UE candidates for positioning of the target UE based on the obtained information. 126. The device of clause 125, wherein, to obtain the information, the at least one processor is configured to cause the device to obtain, from one or more of the plurality of anchor UE candidates, one or more location measurements of the anchor UE candidates and a measurement quality metric for each of the one or more location measurements. 127. One or more devices of clauses 125-126, wherein, to obtain the information, at least one processor is configured to cause the device to obtain anchor UE candidate mobility states for one or more of the plurality of anchor UE candidates. 128. One or more devices of clauses 125-126, wherein, to obtain the information, at least one processor is configured to cause the device to obtain information related to a plurality of GDOPs, each GDOP determined for a different combination of anchor UE candidates for the target UE from a plurality of anchor UE candidates. 129. A non-transitory computer-readable medium containing instructions, the instructions, when executed by at least one processor of a device configured to select an anchor UE for positioning of a target user equipment (UE) in a wireless network, causing the device to: location measurement results and measurement quality measures for one or more candidate anchor UEs; the mobility state of one or more anchor UE candidates, or Geometric Dilution of Precision (GDOP) associated with one or more anchor UE candidates obtain information relating to one or more of the following: A non-transitory computer-readable medium for selecting at least one anchor UE candidate from a plurality of anchor UE candidates for positioning of the target UE based on the obtained information. 130. The computer-readable medium of clause 129, wherein execution of the instructions causes the device, in obtaining the information, to obtain, from one or more of the plurality of anchor UE candidates, one or more location measurements of the anchor UE candidates and a measurement quality metric for each of the one or more location measurements. 131. The computer-readable medium of one or more of clauses 129-130, wherein execution of the instructions causes the device, upon obtaining the information, to obtain anchor UE candidate mobility state for one or more of the plurality of anchor UE candidates. 132. The computer-readable medium of one or more of clauses 129-131, wherein execution of the instructions causes the device, in obtaining the information, to obtain information related to multiple GDOPs, each GDOP determined for a different combination of anchor UE candidates for the target UE from the multiple anchor UE candidates. 133. A device configured to select an anchor user equipment (UE) for positioning of a target user equipment (UE) in a wireless network, comprising: location measurement results and measurement quality measures for one or more candidate anchor UEs; the mobility state of one or more anchor UE candidates, or Geometric Dilution of Precision (GDOP) associated with one or more anchor UE candidates means for obtaining information relating to one or more of: and means for selecting at least one anchor UE candidate from a plurality of anchor UE candidates for positioning of the target UE based on the obtained information. 134. The device of clause 133, wherein the means for obtaining information includes means for obtaining, from one or more of the plurality of anchor UE candidates, one or more location measurements of the anchor UE candidates and a measurement quality metric for each of the one or more location measurements. 135. The device of one or more of clauses 133-134, wherein the means for obtaining information includes means for obtaining, for one or more of the plurality of anchor UE candidates, mobility state of the anchor UE candidate. 136. The device or devices of clauses 133 to 135, wherein the means for obtaining information includes means for obtaining information related to a plurality of GDOPs, each GDOP determined for a different combination of anchor UE candidates for the target UE from a plurality of anchor UE candidates.

[0180] It is therefore intended that claimed subject matter not be limited to the particular examples disclosed, but that such claimed subject matter may include all embodiments falling within the scope of the appended claims and equivalents thereof. [Explanation of symbols]

[0181] 100 Wireless Communication System 102 Base station (BS) 104 UE, target UE 110 Geographic Coverage Areas 120 Communication Links 122 backhaul links 134 backhaul links 150 AP 152 UE 154 communication links 164 UE 180 mmW BS 182 UE 184 mmW communication link 190 UE 192 D2D P2P links 194 D2D P2P links 170 Core Network 172 Location Server 212 Data Sources 220 Transmit Processor 230 TX MIMO Processor 232 Modulator 234 Antenna 236 MIMO detector 238 Receive Processor 239 Data Sink 240 Controllers / Processors 242 memory 244 communication unit 246 Scheduler 252 Antenna 254 demodulator 256 MIMO detector 258 Receive Processor 260 Data Sink 262 Data Sources 264 Transmit Processor 266 TX MIMO Processor 280 Controller / Processor 282 memory 290 Controller / Processor 292 memory 294 Communication Unit 300 User Equipment (UE) 310 processor 311 memory 312 Software 313 Sensor 314 Transceiver Interface 315 Transceiver 316 User Interface 317 SPS receiver 318 Camera 319 Location Device 320 Bus 330 Application Processor 331 DSP 332 modem processor 333 Video Processor 334 Sensor Processor 340 Wireless Transceiver 342 Transmitter 344 Receiver 346 Antenna 348 Wireless Signal 350 Wired Transceiver 352 Transmitter 354 Receiver 360 SPS signal 362 SPS Antenna 372 Anchor UE Selection Session Module 400 base stations 410 processor 411 memory 412 Software 415 Transceiver 420 Bus 440 Wireless Transceiver 442 Transmitter 444 receiver 446 Antenna 448 Wireless Signal 450 Wired Transceiver 452 Transmitter 454 receiver 472 Anchor UE Selection Session Module 500 servers 510 processor 511 memory 512 Software 515 Transceiver 520 Bus 540 Wireless Transceiver 542 Transmitter 544 Receiver 546 Antenna 548 Wireless Signal 550 Wired Transceiver 552 Transmitter 554 Receiver 902 TRP 904 TRP 906 range 908 range 910 Location Uncertainty

Claims

1. 1. A method for selecting an anchor user equipment (UE) for positioning of a target user equipment (UE) in a wireless network, comprising: obtaining, from one or more of a plurality of anchor UE candidates, one or more location measurements of the anchor UE candidates and a measurement quality metric for each of the one or more location measurements, the measurement quality metric differing based on whether the location measurement associated with the measurement quality metric is radio access technology (RAT) independent or RAT dependent; selecting at least one anchor UE candidate from the plurality of anchor UE candidates for positioning of the target UE based on the one or more measurement quality metrics from the one or more anchor UE candidates.

2. 2. The method of claim 1, wherein obtaining the one or more location measurement results and measurement quality measures of the candidate anchor UE comprises obtaining the one or more location measurement results and measurement quality measures of the candidate anchor UE in one or more NR-based positioning-related measurement reports from the candidate anchor UE.

3. 3. The method of claim 2, wherein the one or more location measurements include one or more reference signal time differences (RSTDs) measured by the anchor UE candidate using positioning reference signal (PRS) resources obtained from one or more devices in the wireless network.

4. UE-based positioning is performed by the target UE; The method of claim 3 , wherein the one or more positioning-related measurement reports are obtained by the target UE from the candidate anchor UE via a side link (SL) between the target UE and the candidate anchor UE.

5. The method of claim 4 , further comprising providing, by the target UE, one or more of the PRS resources to the candidate anchor UE via the SL.

6. UE-assisted positioning for the target UE is performed by a location server of the wireless network; one or more of the PRS resources are provided by a base station to the anchor UE candidate on a downlink (DL); the one or more positioning-related measurement reports are provided from a candidate anchor UE to the base station; the one or more location measurement results and measurement quality metrics from the one or more positioning-related measurement reports are provided from the base station to the location server; 4. The method of claim 3, wherein selecting the at least one anchor UE candidate comprises the location server selecting the anchor UE candidate as the anchor UE based on the one or more location measurement results and measurement quality metrics.

7. The method of claim 1 , wherein for the one or more anchor UE candidates, each location measurement result and associated measurement quality metric is radio access technology (RAT) independent.

8. The method of claim 7 , wherein each location measurement and associated measurement quality metric is determined by the anchor UE candidate using a Global Navigation Satellite System (GNSS).

9. UE-based positioning is performed by the target UE; 8. The method of claim 7, wherein the one or more location measurement results and measurement quality metrics of a candidate anchor UE are obtained from the candidate anchor UE via a side link (SL) between the target UE and the candidate anchor UE.

10. UE-assisted positioning of the target UE is performed by a location server of the wireless network; providing the one or more location measurements and measurement quality metrics from a candidate anchor UE to a base station; the one or more location measurements and measurement quality measures are provided from the base station to the location server; 8. The method of claim 7, wherein selecting the at least one anchor UE candidate comprises the location server selecting the anchor UE candidate as the anchor UE based on the one or more location measurement results and measurement quality metrics.

11. The method of claim 1 , further comprising determining a variance of the measurement quality metric for the plurality of anchor UE candidates, wherein selecting the at least one anchor UE candidate is based on the determined variance.

12. The method of claim 11 , wherein the variability comprises the mean and variance of the measurement quality measure.

13. 2. The method of claim 1, wherein the step of selecting the at least one anchor UE candidate is also based on a link quality of a side link (SL) between the target UE and the one or more anchor UE candidates.

14. 1. A device configured to select an anchor user equipment (UE) for positioning of a target user equipment (UE) in a wireless network, the device comprising: at least one transceiver; at least one memory; and at least one processor coupled to the at least one transceiver and the at least one memory, the at least one processor causing the device to: obtaining, via the at least one transceiver, from one or more of a plurality of anchor UE candidates, one or more location measurements of the anchor UE candidates and a measurement quality metric for each of the one or more location measurements, the measurement quality metric varying based on whether a location measurement associated with the measurement quality metric is radio access technology (RAT) independent or RAT dependent; selecting, via the at least one processor, at least one anchor UE candidate from the plurality of anchor UE candidates for positioning of the target UE based on the one or more measurement quality metrics from the one or more anchor UE candidates. The device is configured to:

15. 1. A non-transitory computer-readable storage medium having stored thereon instructions, which, when executed by at least one processor of a device configured to select an anchor UE for positioning of a target user equipment (UE) in a wireless network, cause the device to: causing at least one transceiver to obtain, from one or more of a plurality of anchor UE candidates, one or more location measurements of the anchor UE candidates and a measurement quality metric for each of the one or more location measurements, the measurement quality metric varying based on whether a location measurement associated with the measurement quality metric is radio access technology (RAT) independent or RAT dependent; A non-transitory computer-readable storage medium that causes the at least one processor to select at least one anchor UE candidate from the plurality of anchor UE candidates for positioning of the target UE based on the one or more measurement quality metrics from the one or more anchor UE candidates.

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