Enhanced sidelink assisted hybrid network positioning

Abstract

Location determination of a target user equipment (UE) uses a single base station and multiple sidelink UEs with known locations. The base station transmits reference signals to the target UE and the sidelink UEs, and the target UE transmits a sidelink signal to each of the sidelink UEs. Based on the time difference between reception and transmission of the reference signals measured by the target UE and the time difference between receptions of the reference signals measured by the sidelink UEs, a range sum of the distance between the target UE and the sidelink UE and the distance between the sidelink UE and the base station can be determined for each of the sidelink UEs. A difference in the range sums can be determined and used to determine the location of the target UE.

Description

[0001] Cross-references to related applications

[0002] This application claims priority and interest in Greek Patent Application No. 20210100310 entitled "ENHANCED SIDELINK-AIDED HYBRID NETWORK POSITIONING" filed on May 6, 2021, and Greek Application No. 20200100746 entitled "SIDELINK-AIDED HYBRID NETWORK POSITIONING" filed on December 23, 2020, both of which are assigned to the assignee and whose entire contents are expressly incorporated herein by reference. Technical Field

[0003] This invention relates generally to the field of wireless communication, and more specifically, to determining the location (or positioning) of a user equipment (UE) using radio frequency (RF) signals. Background Technology

[0004] In data communication networks, various positioning techniques can be used to determine the location of mobile devices (here referred to as user equipment or UE). Some of these techniques may involve determining distance and / or angle information from RF signals received by one or more base stations of the data communication network. However, these determinations typically require the mobile device to communicate with multiple base stations. Communicating in this manner often exceeds the power budget of some low-power mobile devices. Summary of the Invention

[0005] The location of a target user equipment (UE) is determined using a single base station and multiple sidelink UEs with known locations relative to the base station. The base station transmits a reference signal to the target UE and the sidelink UEs, and the target UE transmits a sidelink signal to each sidelink UE. Based on the time difference between the reception and transmission of the reference signal measured by the target UE and the time difference between the reception of the reference signal measured by the sidelink UEs, the sum of the distances between the target UE and the sidelink UE and the distance between the sidelink UE and the base station can be determined for each sidelink UE. The difference in the sum of distances can be determined and used to determine the location of the target UE, for example, as the intersection of two hyperbolas from the known locations of the sidelink UEs.

[0006] In one embodiment, a method performed by a first user equipment (UE) for determining a location of the first UE, the method comprising receiving a first reference signal from a network entity; transmitting one or more sidelink reference signals to a plurality of sidelink UEs; determining a receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference between receiving the first reference signal from the network entity and transmitting the sidelink reference signal to the respective sidelink UE; and processing the Rx-Tx time difference associated with each sidelink UE based on the Rx-Tx time difference associated with each sidelink UE and a time difference measured by each sidelink UE to generate differential range sums for the plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving the sidelink reference signal from the first UE and receiving a second reference signal from the network entity, each differential range sum is a difference between a range sum from a reference sidelink UE of the plurality of sidelink UEs and a range sum from another sidelink UE of the plurality of sidelink UEs, and wherein the range sum for each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE, wherein the location of the first UE is determined based at least in part on the differential range sums for the plurality of sidelink UEs.

[0007] In one embodiment, a first user equipment (UE) configured for determining a location of the first UE, the first UE comprising: at least one wireless transceiver configured to wirelessly communicate with other entities in a wireless network; at least one memory; and at least one processor coupled to the at least one wireless transceiver and the at least one memory and configured to: receive, via the at least one wireless transceiver, a first reference signal from a network entity; transmit, via the at least one wireless transceiver, one or more sidelink reference signals to a plurality of sidelink UEs; determine a receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference between receiving the first reference signal from the network entity and transmitting the sidelink reference signal to the respective sidelink UE; and process the Rx-Tx time difference associated with each sidelink UE based on the Rx-Tx time difference associated with each sidelink UE and a time difference measured by each sidelink UE to generate differential range sums for the plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving the sidelink reference signal from the first UE and receiving a second reference signal from the network entity, each differential range sum is a difference between a range sum from a reference sidelink UE of the plurality of sidelink UEs and a range sum from another sidelink UE of the plurality of sidelink UEs, and wherein the range sum for each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE, wherein the location of the first UE is determined based at least in part on the differential range sums for the plurality of sidelink UEs.

[0008] In one embodiment, a first user equipment (UE) configured for determining a location of the first UE, the first UE comprising: means for receiving a first reference signal from a network entity; means for transmitting one or more sidelink reference signals to a plurality of sidelink UEs; means for determining a receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference between receiving the first reference signal from the network entity and transmitting the sidelink reference signal to the respective sidelink UE; and means for processing the Rx-Tx time difference associated with each sidelink UE based on the Rx-Tx time difference associated with each sidelink UE and a time difference measured by each sidelink UE to generate differential range sums of the plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving the sidelink reference signal from the first UE and receiving a second reference signal from the network entity, each differential range sum is a difference between a range sum of a reference sidelink UE from the plurality of sidelink UEs and a range sum of another sidelink UE from the plurality of sidelink UEs, and wherein the range sum of each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE, wherein the location of the first UE is determined based at least in part on the differential range sums of the plurality of sidelink UEs.

[0009] In one embodiment, a non-transitory storage medium including program code stored thereon, the program code is operable to configure at least one processor in a first user equipment (UE) configured for determining a location of the first UE, the program code comprising instructions to: receive a first reference signal from a network entity; transmit one or more sidelink reference signals to a plurality of sidelink UEs; determine a receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference between receiving the first reference signal from the network entity and transmitting the sidelink reference signal to the respective sidelink UE; and process the Rx-Tx time difference associated with each sidelink UE based on the Rx-Tx time difference associated with each sidelink UE and a time difference measured by each sidelink UE to generate differential range sums of the plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving the sidelink reference signal from the first UE and receiving a second reference signal from the network entity, each differential range sum is a difference between a range sum of a reference sidelink UE from the plurality of sidelink UEs and a range sum of another sidelink UE from the plurality of sidelink UEs, and wherein the range sum of each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE, wherein the location of the first UE is determined based at least in part on the differential range sums of the plurality of sidelink UEs.

[0010] In one implementation, a method performed by a location server for determining a location of a first user equipment (UE), the method comprising obtaining, based on a receive-transmit (Rx-Tx) time difference associated with each sidelink UE measured by the first UE, differential range sums for the first UE and a plurality of sidelink UEs, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference measured by the first UE between receiving a first reference signal from a network entity and transmitting a sidelink reference signal to the respective sidelink UE, wherein the differential range sums for the first UE and the plurality of sidelink UEs are further based on time differences measured by the plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving a sidelink reference signal from the first UE and receiving a second reference signal from the network entity, wherein each differential range sum is a difference between a range sum for a reference sidelink UE from the plurality of sidelink UEs and a range sum for another sidelink UE from the plurality of sidelink UEs, and wherein the range sum for each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE; and determining the location of the first UE based at least in part on the differential range sums for the plurality of sidelink UEs.

[0011] In one implementation, a location server configured for determining a location of a first user equipment (UE), the location server comprising: an external interface configured for communication with other entities in a wireless network; at least one memory; and at least one processor coupled to the external interface and the at least one memory and configured to: obtain, via the external interface, differential range sums for the first UE and a plurality of sidelink UEs based on a receive-transmit (Rx-Tx) time difference associated with each sidelink UE measured by the first UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference measured by the first UE between receiving a first reference signal from a network entity and transmitting a sidelink reference signal to the respective sidelink UE, wherein the differential range sums for the first UE and the plurality of sidelink UEs are further based on time differences measured by the plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving a sidelink reference signal from the first UE and receiving a second reference signal from the network entity, wherein each differential range sum is a difference between a range sum for a reference sidelink UE from the plurality of sidelink UEs and a range sum for another sidelink UE from the plurality of sidelink UEs, and wherein the range sum for each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE; and determine the location of the first UE based at least in part on the differential range sums for the plurality of sidelink UEs.

[0012] In one implementation, a location server configured for determining a location of a first user equipment (UE) includes means for obtaining differential range sums of the first UE and a plurality of sidelink UEs based on a receive-transmit (Rx-Tx) time difference associated with each sidelink UE measured by the first UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference measured by the first UE between receiving a first reference signal from a network entity and transmitting a sidelink reference signal to the respective sidelink UE, wherein the differential range sums of the first UE and the plurality of sidelink UEs are further based on time differences measured by the plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving a sidelink reference signal from the first UE and receiving a second reference signal from the network entity, wherein each differential range sum is a difference between a range sum of a reference sidelink UE from the plurality of sidelink UEs and a range sum of another sidelink UE from the plurality of sidelink UEs, and wherein the range sum of each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE; and means for determining the location of the first UE based at least in part on the differential range sums of the plurality of sidelink UEs.

[0013] In one implementation, a non-transitory storage medium including program code stored thereon, the program code is operable to configure at least one processor in a location server for determining a location of a first user equipment (UE), the program code comprising instructions to: obtain differential range sums of the first UE and a plurality of sidelink UEs based on a receive-transmit (Rx-Tx) time difference associated with each sidelink UE measured by the first UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference measured by the first UE between receiving a first reference signal from a network entity and transmitting a sidelink reference signal to the respective sidelink UE, wherein the differential range sums of the first UE and the plurality of sidelink UEs are further based on time differences measured by the plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving a sidelink reference signal from the first UE and receiving a second reference signal from the network entity, wherein each differential range sum is a difference between a range sum of a reference sidelink UE from the plurality of sidelink UEs and a range sum of another sidelink UE from the plurality of sidelink UEs, and wherein the range sum of each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE; and determine the location of the first UE based at least in part on the differential range sums of the plurality of sidelink UEs.

[0014] In one embodiment, a method for determining the location of a first user equipment (UE) performed by a location server includes receiving time differences measured by a plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is the time difference between the first UE receiving a sidelink reference signal and receiving a reference signal from a network entity; and transmitting the time differences measured by the plurality of sidelink UEs to the first UE to determine the location of the first UE based on the time differences measured by the plurality of sidelink UEs and a receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is the time difference measured by the first UE between receiving a second reference signal from a network entity and transmitting a sidelink reference signal to the corresponding sidelink UE.

[0015] In one embodiment, a location server is configured to determine the location of a first user equipment (UE), the location server comprising: an external interface configured to communicate with other entities in a wireless network; at least one memory; and at least one processor coupled to the external interface and the at least one memory and configured to: receive time differences measured by a plurality of sidelink UEs via the external interface, wherein the time difference measured by each sidelink UE is the time difference between the first UE receiving a sidelink reference signal and receiving a reference signal from a network entity; and transmit the time differences measured by the plurality of sidelink UEs to the first UE via the external interface to determine the location of the first UE based on the time differences measured by the plurality of sidelink UEs and the receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is the time difference measured by the first UE between receiving a second reference signal from a network entity and transmitting a sidelink reference signal to the corresponding sidelink UE.

[0016] In one embodiment, a location server is configured to determine the location of a first user equipment (UE), the location server comprising: means for receiving time differences measured by a plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is the time difference between the first UE receiving a sidelink reference signal and receiving a reference signal from a network entity; and means for transmitting the time differences measured by the plurality of sidelink UEs to the first UE to determine the location of the first UE based on the time differences measured by the plurality of sidelink UEs and a receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is the time difference measured by the first UE between receiving a second reference signal from a network entity and transmitting a sidelink reference signal to the corresponding sidelink UE.

[0017] In one embodiment, a non-transitory storage medium including program code stored thereon, the program code is operable to configure at least one processor in a location server for determining a location of a first user equipment (UE), the program code comprising instructions to: receive time differences measured by a plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving a sidelink reference signal from the first UE and receiving a reference signal from a network entity; and send the time differences measured by the plurality of sidelink UEs to the first UE to determine the location of the first UE based on the time differences measured by the plurality of sidelink UEs and a receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference measured by the first UE between receiving a second reference signal from the network entity and transmitting a sidelink reference signal to the respective sidelink UE.

[0018] In one embodiment, a method performed by a first user equipment (UE) for determining a location of a second UE, the first UE in sidelink communication with the second UE, the method comprising receiving a first reference signal from a network entity; receiving a sidelink reference signal from the second UE; and determining a time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity; and processing the time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity to generate differential range sums of the second UE and a plurality of sidelink UEs including the first UE based on receive-transmit (Rx-Tx) time differences associated with each sidelink UE measured by the second UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference measured by the second UE between receiving a second reference signal from the network entity and transmitting a sidelink reference signal to the respective sidelink UE, wherein the differential range sums of the second UE and the plurality of sidelink UEs are further based on time differences measured by the plurality of sidelink UEs, wherein each differential range sum is a difference between a range sum from a reference sidelink UE of the plurality of sidelink UEs and a range sum from another sidelink UE of the plurality of sidelink UEs, and wherein the range sum of each sidelink UE is a sum of a first distance between the second UE and the network entity and a second distance between the second UE and the respective sidelink UE, and wherein the location of the second UE is determined based at least in part on the differential range sums of the plurality of sidelink UEs.

[0019] In one embodiment, a first user equipment (UE) configured for determining a location of a second UE, the first UE in sidelink communication with the second UE, the first UE comprising: at least one wireless transceiver configured to wirelessly communicate with other entities in a wireless network; at least one memory; and at least one processor coupled to the at least one wireless transceiver and the at least one memory and configured to: receive, via the at least one wireless transceiver, a first reference signal from a network entity; receive, via the at least one wireless transceiver, a sidelink reference signal from the second UE; and determine a time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity; and process the time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity to generate a differential range sum of the second UE and a plurality of sidelink UEs including the first UE based on a receive-transmit (Rx-Tx) time difference associated with each sidelink UE measured by the second UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference between receiving a second reference signal from the network entity and transmitting the sidelink reference signal to the respective sidelink UE measured by the second UE, wherein the differential range sum of the second UE and the plurality of sidelink UEs is further based on the time differences measured by the plurality of sidelink UEs, wherein each differential range sum is a difference between a range sum from a reference sidelink UE of the plurality of sidelink UEs and a range sum from another sidelink UE of the plurality of sidelink UEs, and wherein the range sum of each sidelink UE is a sum of a first distance between the second UE and the network entity and a second distance between the second UE and the respective sidelink UE, and wherein the location of the second UE is determined based at least in part on the differential range sums of the plurality of sidelink UEs.

[0020] In one embodiment, a first user equipment (UE), configured for determining a location of a second UE, the first UE in sidelink communication with the second UE, the first UE comprising: means for receiving a first reference signal from a network entity; means for receiving a sidelink reference signal from the second UE; and means for determining a time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity; and means for processing the time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity to generate a differential range sum of the second UE and a plurality of sidelink UEs including the first UE based on a receive-transmit (Rx-Tx) time difference associated with each sidelink UE measured by the second UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference measured by the second UE between receiving a second reference signal from the network entity and transmitting a sidelink reference signal to the respective sidelink UE, wherein the differential range sum of the second UE and the plurality of sidelink UEs is further based on the time differences measured by the plurality of sidelink UEs, wherein each differential range sum is a difference between a range sum of a reference sidelink UE from the plurality of sidelink UEs and a range sum of another sidelink UE from the plurality of sidelink UEs, and wherein the range sum of each sidelink UE is a sum of a first distance between the second UE and the network entity and a second distance between the second UE and the respective sidelink UE, and wherein the location of the second UE is determined based at least in part on the differential range sums of the plurality of sidelink UEs.

[0021] In one embodiment, a non-transitory storage medium including program code stored thereon, the program code is operable to configure at least one processor in a first user equipment (UE) for determining a location of a second UE, the first UE in sidelink communication with the second UE, the program code comprising instructions to: receive a first reference signal from a network entity; receive a sidelink reference signal from the second UE; and determine a time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity; and process the time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity to generate a differential range sum of the second UE and a plurality of sidelink UEs including the first UE based on a receive-transmit (Rx-Tx) time difference associated with each sidelink UE measured by the second UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference measured by the second UE between receiving a second reference signal from the network entity and transmitting a sidelink reference signal to the respective sidelink UE, wherein the differential range sum of the second UE and the plurality of sidelink UEs is further based on the time differences measured by the plurality of sidelink UEs, wherein each differential range sum is a difference between a range sum from a reference sidelink UE of the plurality of sidelink UEs and a range sum from another sidelink UE of the plurality of sidelink UEs, and wherein the range sum of each sidelink UE is a sum of a first distance between the second UE and the network entity and a second distance between the second UE and the respective sidelink UE, and wherein the location of the second UE is determined based at least in part on the differential range sums of the plurality of sidelink UEs. BRIEF DESCRIPTION OF DRAWINGS

[0022] The claimed subject matter is particularly pointed out and distinctly claimed in the concluding portion of the specification. The claimed subject matter, however, both as to organization and / or method of operation, together with objects and advantages thereof, can best be understood by reference to the following detailed description, taken in conjunction with the accompanying drawings in which:

[0023] Figure 1 is a diagram of a positioning system according to an embodiment.

[0024] Figure 2 is a diagram of a fifth generation (5G) New Radio (NR) positioning system showing embodiments of a positioning system (e.g., the positioning system of Figure 1 ) implemented within a 5G NR communication system.

[0025] Figure 3 is a diagram showing beamforming in a 5G NR positioning system.

[0026] Figure 4A is a diagram showing exemplary timing within a round trip time (RTT) measurement during a wireless probe request and response.

[0027] Figure 4B A simplified environment and example techniques for eliminating UE-based group delay related errors using a differential approach to determine a location of a UE are shown.

[0028] Figure 5 is a simplified diagram showing location determination of a target UE can be performed using a single base station and a single sidelink UE using a range and

[0029] Figure 6 is a time-range diagram showing timing of determining a location of a target UE in the network configuration shown. Figure 5

[0030] Figure 7A and Figure 7B is a diagram of a base station, a target UE, and a sidelink UE showing different configurations of beams that can be used for positioning.

[0031] Figure 8 is a simplified diagram showing location determination of a target UE using a single base station and multiple sidelink UEs using a differential range sum.

[0032] Figure 9 is a call flow diagram showing a procedure for performing UE-based positioning of a target UE using a differential range sum.

[0033] Figure 10 is a call flow diagram showing a procedure for performing UE-assisted positioning of a target UE using a differential range sum.

[0034] Figure 11 shows a schematic block diagram illustrating certain example features of a UE configured to support positioning using a differential range sum.

[0035] Figure 12 shows a schematic block diagram illustrating certain example features of a location server configured to support positioning using a differential range sum.

[0036] Figure 13 shows a flow diagram of an example method for determining a location of a target UE performed by a target UE in a manner consistent with the disclosed implementations.

[0037] Figure 14 shows a flow diagram of an example method for determining a location of a target UE performed by a location server in a manner consistent with the disclosed implementations.

[0038] Figure 15 shows a flow diagram of an example method for determining a location of a target UE performed by a location server in a manner consistent with the disclosed implementations.

[0039] Figure 16 ​A flow diagram illustrating an exemplary method for determining a location of a target UE performed by a sidelink UE in a manner consistent with the disclosed implementations is shown.

[0040] According to certain example implementations, like reference numerals in the various drawings indicate like elements. Furthermore, multiple instances of an element can be indicated by a first number followed by a letter or a hyphen and a second number. For example, multiple instances of an element 210 can be indicated as 210-1, 210-2, 210-3, etc. or 210a, 210b, 210c, etc. When only the first number is used in reference to such an element, it should be understood as any instance of that element (e.g., element 210 in the previous example would refer to elements 110-1, 210-2, and 210-3 or elements 210a, 210b, and 210c).

[0041] It should be appreciated that the drawings are not necessarily drawn to scale, e.g., for the sake of simplicity and / or clarity. For example, the dimensions of some of the aspects can be exaggerated relative to other aspects. Furthermore, it should be appreciated that other embodiments can be utilized. Additionally, it should be appreciated that structural and / or other changes can be made without departing from the scope of the claimed subject matter. Reference throughout this specification to “claimed subject matter” means the subject matter intended to be encompassed by one or more claims or any portion thereof, and is not necessarily intended to refer to the complete set of claims, a particular combination of claim sets (e.g., method claims, apparatus claims, etc.), or a particular claim. It should also be noted that directions and / or references, e.g., such as up, down, top, bottom, etc., can be used for facilitating discussion of the drawings and are not intended to limit application of the claimed subject matter. Accordingly, the following detailed description does not limit the claimed subject matter and / or equivalents. DETAILED DESCRIPTION

[0042] Several illustrative embodiments will now be described with reference to the drawings, which form a part of this disclosure. Although other embodiments of one or more aspects of the disclosure can be implemented, some embodiments will be described, by way of example, with reference to the following drawings. It should be noted that the following figures are not drawn to scale and are merely intended to illustrate some embodiments of the disclosure.

[0043] As used herein, an “RF signal” or “reference signal” includes an electromagnetic wave that transports information between a transmitter (or transmitting device) and a receiver (or receiving device) through the space between them. As used herein, a transmitter can transmit a single “reference signal” or multiple “reference signals” to a receiver. However, due to the propagation characteristics of RF signals through multipath channels, the receiver (or a different receiver) can receive multiple “reference signals” corresponding to each transmitted RF signal. The same transmitted RF signal on different paths between the transmitter and receiver can be referred to as a “multipath” RF signal.

[0044] Figure 1This is a simplified illustration of a positioning system 100 according to one embodiment, wherein a UE 105, a location server 160, and / or other components of the positioning system 100 may use the techniques provided herein to determine the estimated location of the UE 105. The techniques described herein may be implemented by one or more components of the positioning system 100. The positioning system 100 may include a UE 105, one or more sidelink (SL) UEs 105a, one or more satellites 110 (also referred to as spacecraft (SV)) for a Global Navigation Satellite System (GNSS) such as Global Positioning System (GPS), a base station 120, an access point (AP) 130, a location server 160, a network 170, and an external client 180. For ease of reference, UE 105 and SL UE 105a may sometimes be collectively referred to herein as UE 105. Positioning system 100 can estimate the position of UE 105 and / or SL UE 105a based on RF signals received and / or transmitted by UE 105 and other components transmitting and / or receiving RF signals (e.g., GNSS satellite 110, base station 120, AP 130). Additional details regarding specific position estimation techniques will be provided later. Figure 2 It was discussed in detail.

[0045] It should be noted that, Figure 1 Only a general illustration of the various components is provided; any or all of them may be used appropriately, and each component may be repeated as needed. Specifically, although only UE 105 and SL UE 105a are shown, it will be understood that many UEs (e.g., hundreds, thousands, millions, etc.) can utilize positioning system 100. Similarly, positioning system 100 may include more than Figure 1 The diagram shows a greater or lesser number of base stations 120 and / or access points 130. The connections shown for the various components in the positioning system 100 include data and signaling connections, which may include additional (intermediate) components, direct or indirect physical and / or wireless connections, and / or additional networks. Furthermore, components may be rearranged, combined, separated, replaced, and / or omitted depending on the desired functionality. In some embodiments, for example, an external client 180 may connect directly to the location server 160. Those skilled in the art will recognize numerous modifications to the illustrated components.

[0046] Depending on the desired functionality, network 170 can comprise any of a variety of wireless and / or wired networks. Network 170 may, for example, comprise any combination of public and / or private networks, local and / or wide-area networks, and the like. Further, network 170 can utilize one or more wired and / or wireless communication technologies. In some embodiments, network 170 can comprise, for example, a cellular or other mobile network, a wireless local area network (WLAN), a wireless wide-area network (WW AN), and / or the Internet. Examples of network 170 include a Long-Term Evolution (LTE) wireless network, a Fifth Generation (5G) wireless network (also referred to as a New Radio (NR) wireless network or a 5G NR wireless network), a Wi-Fi WLAN, and the Internet. LTE, 5G, and NR are wireless technologies defined or being defined by the Third Generation Partnership Project (3GPP). Network 170 can also comprise more than one network and / or more than one type of network.

[0047] Base stations 120 and access points (APs) 130 are communicatively coupled to network 170. In some embodiments, base stations 120 can be owned, maintained, and / or operated by a cellular network provider and can employ any of a variety of wireless technologies as described below. Depending on the technology of network 170, base stations 120 can comprise a node B, an evolved Node B (eNodeB or eNB), a base transceiver station (BTS), a radio base station (RBS), an NR NodeB (gNB), a next generation eNB (ng-eNB), or the like. Base stations 120 that are gNBs or ng-eNBs can be part of a Next Generation Radio Access Network (NG-RAN), which can connect to a 5G Core (5GC) in the case that network 170 is a 5G network. For example, APs 130 can comprise Wi-Fi APs or APs. Thus, UE 105 can send and receive information with network-connected devices, such as location server 160, by accessing network 170 via base stations 120 using first communication links 133. Additionally or alternatively, because APs 130 can also be communicatively coupled with network 170, UE 105 can communicate with Internet-connected devices, including location server 160, using second communication links 135. Further, UE 105 can send and receive information directly with sidelink-connected devices (e.g., SL UE 105a) using third communication links 137.

[0048] As used herein, the term “base station” can generally refer to a single physical transmission point, or multiple co-located physical transmission points that can be located at the base station 120. A transmission reception point (TRP) (also referred to as a transmission / reception point) corresponds to this type of transmission point, and the term “TRP” can be used interchangeably herein with the terms “gNB,” “ng-eNB,” and “base station.” A physical transmission point can include an array of antennas of a base station (e.g., as in a multiple-input multiple-output (MIMO) system and / or where the base station employs beamforming). The term “base station” can additionally refer to multiple non-colocated physical transmission points, which can be a distributed antenna system (DAS) (a network of spatially separated antennas connected to a common source via transmission media) or a remote radio head (RRH) (a remote base station connected to a serving base station). Alternatively, the non-co-located physical transmission points can be a serving base station that receives the measurement report from the UE 105 and a neighbor base station whose reference RF signals the UE 105 is measuring.

[0049] As used herein, the term “cell” can generally refer to a logical communication entity for communication with base stations 120 and can be associated with an identifier (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID)) used to distinguish neighboring cells operating via the same or different carrier. In some examples, a carrier can support multiple cells, and different cells can be configured according to different protocol types (e.g., machine type communication (MTC), narrowband Internet of Things (NB-IoT), enhanced mobile broadband (eMBB), or others) that can provide access for different types of devices. In some cases, the term “cell” can refer to a portion of a geographic coverage area (e.g., a sector) on which a logical entity operates.

[0050] The location server 160 can include a server and / or other computing devices configured to determine an estimated position of the UE 105 and / or to provide data (e.g., “assistance data”) to the UE 105 to facilitate position determination. According to some embodiments, the location server 160 can include a Home Secure User Plane Location (SUPL) Location Platform (H-SLP), which can support the SUPL User Plane (UP) location solution defined by the Open Mobile Alliance (OMA) and can support location services for the UE 105 based on subscription information for the UE 105 stored in the location server 160. In some embodiments, the location server 160 can include a Discovered SLP (D-SLP) or an Emergency SLP (E-SLP). The location server 160 can also include an Enhanced Serving Mobile Location Center (E-SMLC), which supports positioning of the UE 105 using a Control Plane (CP) location solution for LTE radio access for the UE 105. The location server 160 can also include a Location Management Function (LMF), which supports positioning of the UE 105 using a Control Plane (CP) location solution for NR radio access for the UE 105. In CP location solutions, signaling for controlling and managing the location of the UE 105 can be exchanged between elements of the network 170 and with the UE 105 using existing network interfaces and protocols and as signaling from the perspective of the network 170. In UP location solutions, signaling for controlling and managing the location of the UE 105 can be exchanged between the location server 160 and the UE 105 as data (e.g., data sent using the Internet Protocol (IP) and / or the Transmission Control Protocol (TCP)) from the perspective of the network 170.

[0051] As previously noted (and discussed in greater detail below), the estimated position of the UE 105 (and similarly, the estimated position of the SL UE 105a) can be based on measurements of RF signals transmitted from and / or received by the UE 105 (and similarly, the SL UE 105a). Specifically, these measurements can provide information about the relative distance and / or angle of the UE 105 from one or more components in the positioning system 100 (e.g., GNSS satellites 110, APs 130, base stations 120). The estimated position of the UE 105 can be estimated geometrically (e.g., using multilateration and / or multangulation) based on the distance and / or angle measurements and known positions of the one or more components.

[0052] Although ground-based components such as the APs 130 and base stations 120 can be stationary, embodiments are not so limited. Mobile components can be used. Moreover, in some embodiments, the estimated position of the UE 105 is determined based at least in part on measurements of RF signals transmitted from and / or received by one or more other UEs (e.g., the SL UE 105a). Figure 1The position of a UE 105 can be estimated based on measurements of RF signals communicated between UEs (not shown) that can be mobile. Direct communication between UEs in this manner can include sidelink and / or similar device-to-device (D2D) communication techniques. Sidelink as defined by 3GPP is a form of D2D communication under the cellular-based LTE and NR standards.

[0053] The estimated position of a UE 105 can be used for various applications— for example, to assist a user of the UE 105 in finding directions or navigation, or to assist another user (e.g., associated with an external client 180) in locating the UE 105. A “position” is also referred to herein as a “position estimate,” “estimated position,” “location,” “location fix,” “location estimate,” “position fix,” “estimated location,” “location fix,” or “fix.” A position of a UE 105 can include an absolute position of the UE 105 (e.g., latitude and longitude and possibly altitude) or a relative position of the UE 105 (e.g., a position expressed as a distance north or south, east or west, and possibly above or below some other known fixed position or some other position, such as the position of the UE 105 at some known prior time). A position can also be specified as a geodetic position (as latitude and longitude) or a civic position (e.g., in terms of a street address or using other location-related names and labels). A position can also include an indication of uncertainty or error, such as a level of error to which the position is expected to be accurate and possibly an indication of a region or volume (e.g., circular or elliptical) in which the UE 105 is expected to be located with some level of confidence (e.g., 95% confidence).

[0054] An external client 180 can be a web server or remote application that can have some association with a UE 105 (e.g., can be accessible by a user of the UE 105), or can be a server, application, or computer system that provides location services to some other user or users (which can include obtaining and providing a position of a UE 105 (e.g., to enable services such as friend or relative locators, asset tracking, or child or pet location)). Additionally or alternatively, an external client 180 can obtain and provide a position of a UE 105 to an emergency service provider, a government agency, and the like.

[0055] As previously mentioned, the example positioning system 100 can be implemented using a wireless communication network, such as an LTE-based or 5G NR-based network. 5G NR is a wireless RF interface that is being standardized by the 3rd Generation Partnership Project (3GPP). 5G NR promises to provide significantly stronger capabilities than its predecessor (LTE), such as significantly faster and more responsive mobile broadband, enhanced conductivity through Internet of Things (IoT) devices, and more. Furthermore, 5G NR provides new positioning technologies for the UE, including angle of arrival (AoA) / angle of departure (AoD) positioning, UE-based positioning, and multi-cell round-trip time (RTT) positioning. Regarding RTT positioning, this involves performing RTT measurements between the UE and multiple base stations.

[0056] Figure 2 A diagram of a 5G NR positioning system 200 is shown, illustrating an embodiment of a positioning system implementing 5G NR (e.g., positioning system 100). The 5G NR positioning system 200 can be configured to use access nodes 210, 214, 216 (which may correspond to...) Figure 1 The 5G NR positioning system 200 uses base station 120 and access point 130 (optionally) and LMF 220 (which may correspond to location server 160) to determine the location of UE 105 to implement one or more positioning methods. Here, the 5G NR positioning system 200 includes UE 105, SL UE105a, and 5G NR network components including a next-generation (NG) radio access network (RAN) (NG-RAN) 235 and a 5G core network (5G CN) 240. The 5G network may also be referred to as an NR network; NG-RAN 235 may be referred to as 5G RAN or NR RAN; and 5GCN 240 may be referred to as the NG core network. 3GPP is standardizing NG-RAN and 5G CN. Therefore, NG-RAN 235 and 5G CN 240 may conform to current or future standards supported by 3GPP for 5G. The 5G NR positioning system 200 may further utilize information from GNSS satellites 110, which are derived from GNSS systems such as Global Positioning System (GPS) or similar systems. The following describes the additional components of the 5G NR positioning system 200. The 5G NR positioning system 200 may include additional or alternative components.

[0057] It should be noted that, Figure 2Only generalized illustrations of various components are provided, any one or all of which can be utilized as appropriate, and each of which can be repeated or omitted as needed. In particular, although only UE 105 and SL UE 105a are shown, it will be appreciated that many UEs (e.g., hundreds, thousands, millions, etc.) can utilize 5G NR positioning system 200. Similarly, 5G NR positioning system 200 can include a larger (or smaller) number of GNSS satellites 110, gNBs 210, ng-eNBs 214, wireless local area networks (WLANs) 216, access and mobility functions (AMFs) 215, external clients 230, and / or other components. The illustrated connections between various components of 5G NR positioning system 200 include data and signaling connections that can include additional (intermediary) components, direct or indirect physical and / or wireless connections, and / or additional networks. Moreover, components can be rearranged, combined, separated, replaced, and / or omitted in accordance with desired functionality.

[0058] UE 105 can include and / or can be referred to as a device, a mobile device, a wireless device, a mobile terminal, a terminal, a mobile station (MS), a Secure User Plane Location (SUPL)-enabled terminal (SET), or by some other name. Moreover, UE 105 can correspond to a cellphone, a smartphone, a laptop, a tablet, a personal data assistant (PDA), a tracking device, a navigation device, an Internet of Things (IoT) device, or some other portable or moveable device. Typically, although not necessarily, UE 105 can support wireless communication using one or more radio access technologies (RATs), such as using Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA), Wideband CDMA (WCDMA), Long Term Evolution (LTE), High Rate Packet Data (HRPD), IEEE 802.11 Bluetooth, Worldwide Interoperability for Microwave Access (WiMAX TM ), 5G NR (e.g., using NG-RAN 235 and 5G CN 240), etc. UE 105 can also support wireless communication using WLAN 216, which (like the one or more RATs, and as previously described with respect to Figure 1 GMLC 225) can connect to other networks, such as the Internet. Using one or more of these RATs can allow UE 105 to communicate with external client 230 (e.g., via elements of 5G CN 240 not shown in FIG. 1, or possibly via a gateway mobile location center (GMLC) 225) and / or allow external client 230 to receive location information about UE 105 (e.g., via GMLC 225). Figure 2

[0059] ​UE 105 may include a single entity or may include multiple entities, for example, in a personal area network where the user can use audio, video, and / or data I / O devices and / or body sensors, as well as separate wired or wireless modems. The estimation of the location of UE 105 may be referred to as location, location estimation, location fixation, fixation, positioning, location estimation, or location fixation, and may be geodetic, thus providing location coordinates (e.g., latitude and longitude) for UE 105, which may or may not include an elevation component (e.g., height above sea level, height above ground level, floor, or basement, or depth below ground level, floor, or basement). Alternatively, the location of UE 105 may be represented as a city location (e.g., as a postal address or designation of a point or small area within a building, such as a specific room or floor). The location of UE 105 may also be represented as an area or volume (defined geodetically or in urban form) in which UE 105 is expected to be located with a certain probability or confidence level (e.g., 67%, 95%, etc.). The location of the UE 105 can also be a relative location, including, for example, distance and direction, or relative X, Y (and Z) coordinates defined relative to an origin at a known location, which can be defined on the ground, in urban terms, or by reference to a point, area, or volume indicated on a map, floor plan, or building plan. In the description contained herein, the use of the term "location" can include any of these variations unless otherwise indicated. When calculating the location of the UE, local X, Y, and possibly Z coordinates are typically solved, and then, if necessary, the local coordinates are converted to absolute coordinates (e.g., for latitude, longitude, and altitude above or below mean sea level).

[0060] Figure 2 The base station shown in NG-RAN 235 can correspond to Figure 1 The base station 120 in the NG-RAN 235 may include NRNodeB (gNB) 210-1 and 210-2 (collectively and generally referred to herein as gNB 210) and / or the antenna of the gNB. The gNB 210 pairs in the NG-RAN 235 may be connected to each other (e.g., as shown in the image). Figure 2 As shown, access to the 5G network is provided to UE 105 via direct or indirect means through other gNBs 210. This can represent UE 105 providing wireless communication access to the 5G CN 240 using 5G NR. 5G NR radio access can also be referred to as NR radio access or 5G radio access. Figure 2In particular embodiments, assume that the serving gNB for UE 105 is gNB 210-1, although other gNBs (e.g., gNB 210-2) can act as the serving gNB if UE 105 moves to another location, or can act as an auxiliary gNB to provide additional throughput and bandwidth to UE 105.

[0061] Figure 2 The base stations in the illustrated NG-RAN 235 can also or instead include next generation evolved Node Bs, also known as ng-eNBs, 214. An ng-eNB 214 can connect to one or more gNBs 210 in the NG-RAN 235— e.g., directly or indirectly via other gNBs 210 and / or other ng-eNBs. An ng-eNB 214 can provide LTE wireless access and / or evolved LTE (eLTE) wireless access to UE 105. Figure 2 Some gNBs 210 (e.g., gNB 210-2) and / or ng-eNBs 214 in particular embodiments can be configured to act as positioning-only beacons, which can transmit signals (e.g., positioning reference signals (PRS)) and / or can broadcast assistance data to assist in positioning of UE 105, but can not receive signals from UE 105 or other UEs. Note that while Figure 2 Only one ng-eNB 214 is shown in the particular embodiments, but some embodiments can include multiple ng-eNBs 214. Base stations 210, 214 can communicate directly with each other via an Xn communication interface. Additionally or alternatively, base stations 210, 214 can communicate indirectly via another component of 5G NR positioning system 200, such as LMF 220.

[0062] 5G NR positioning system 200 can also include one or more WLANs 216, which can connect to a non-3GPP interworking function (N3IWF) 250 in 5G CN 240 (e.g., in the case of untrusted WLANs 216). For example, WLAN 216 can support IEEE 802.11 Wi-Fi access for UE 105, and can include one or more Wi-Fi APs (e.g., AP 216-1, AP 216-2). In particular embodiments, WLAN 216 can be connected to N3IWF 250 via an N2 communication interface. Figure 1AP 130). Here, the N3IWF 250 can connect to other elements in the 5G CN 240, such as the AMF 215. In some embodiments, the WLAN 216 can support another RAT, such as Bluetooth. The N3IWF 250 can support secure access by the UE 105 to other elements in the 5G CN 240, and / or can support interworking of one or more protocols used by the WLAN 216 and the UE 105 with one or more protocols used by other elements in the 5G CN 240, such as the AMF 215. For example, the N3IWF 250 can support establishment of an IPSec tunnel with the UE 105, termination of IKEv2 / IPSec protocols with the UE 105, termination of N2 and N3 interfaces to the 5G CN 240 for control plane and user plane, respectively, relaying of uplink and downlink control plane Non-Access Stratum (NAS) signaling between the UE 105 and the AMF 215 over the N1 interface. In some other embodiments, the WLAN 216 can connect directly to elements in the 5G CN 240 (e.g., the AMF 215 as shown by the dashed line in Figure 2 Figure 2 Note that while only one WLAN 216 is shown in

[0063] An access node can include any of a variety of network entities capable of communicating between the UE 105 and the AMF 215. This can include a gNB 210, an ng-eNB 214, a WLAN 216, and / or other types of cellular base stations. However, an access node providing the functionality described herein can additionally or alternatively include an entity capable of communicating with any of a variety of RATs not shown in FIG. 2, which can include non-cellular technologies. Thus, the term “access node” as used in embodiments described below can include, but is not necessarily limited to, a gNB 210, an ng-eNB 214, or a WLAN 216. Figure 2

[0064] In some embodiments, an access node such as a gNB 210, an ng-eNB 214, or a WLAN 216 (alone or in combination with other components of the 5G NR positioning system 200) can be configured to, in response to receiving a request for location information for a plurality of RATs from the LMF 220, perform measurements (e.g., measurements by the UE 105) and / or obtain measurements from the UE 105 transmitted to the access node using one or more of the plurality of RATs. As noted, while Figure 2 ​​Access nodes 210, 214, and 216 are depicted that are configured to communicate according to 5G NR, LTE, and Wi-Fi communication protocols, respectively, but access nodes configured to communicate according to other communication protocols can be used, e.g., a Node B using Wideband Code Division Multiple Access (WCDMA) protocol of Universal Mobile Telecommunication Service (UMTS) Terrestrial Radio Access Network (UTRAN), an eNB using Long Term Evolution (LTE) protocol of Evolved UTRAN (E-UTRAN), or a Bluetooth access node using Bluetooth protocol of WLAN. Beacon. For example, in a 4G Evolved Packet System (EPS) that provides LTE wireless access to UE 105, the RAN can comprise an E-UTRAN, which can comprise base stations including eNBs that support LTE wireless access. A core network for the EPS can comprise an Evolved Packet Core (EPC). The EPS can then comprise the E-UTRAN plus the EPC, where the E-UTRAN corresponds to the NG-RAN 235 in Figure 2 Figure 2 the 5G CN 240 in

[0065] ​The gNBs 210 and ng-eNB 214 can communicate with an AMF 215, which communicates with an LMF 220 for positioning functions. The AMF 215 can support mobility of the UE 105, including cell change and handover of the UE 105 from an access node 210, 214, or 216 of a first RAT to an access node 210, 214, or 216 of a second RAT. The AMF 215 can also participate in supporting a signaling connection to the UE 105 and can support data and voice bearers for the UE 105. The LMF 220 can support positioning of the UE 105 when the UE 105 accesses the NG-RAN 235 or the WLAN 216, and can support positioning procedures and methods, including UE-assisted / UE-based and / or network-based procedures / methods such as Assisted GNSS (A-GNSS), Observed Time Difference of Arrival (OTDOA) (which can be referred to as Time Difference of Arrival (TDOA) in NR), Real Time Kinematics (RTK), Precise Point Positioning (PPP), Differential GNSS (DGNSS), ECID, Angle of Arrival (AoA), Angle of Departure (AoD), WLAN positioning, and / or other positioning procedures and methods. The LMF 220 can also process location services requests for the UE 105 received, e.g., from the AMF 215 or from the GMLC 225. The LMF 220 can connect to the AMF 215 and / or the GMLC 225. The LMF 220 can be referred to by other names, such as a Location Manager (LM), Location Function (LF), Commercial LMF (CLMF), or Value Added LMF (VLMF). In some embodiments, a node / system implementing the LMF 220 can additionally or alternatively implement other types of location support modules, such as an Evolved Serving Mobile Location Center (E-SMLC) or a Service Location Protocol (SLP). Note that in some embodiments, at least part of the positioning functionality (including determining a location of a UE) can be performed at the UE 105 (e.g., by processing downlink reference signals, such as DL Positioning Reference Signals (DL-PRS) transmitted by wireless nodes such as the gNBs 210, ng-eNB 214, and / or the WLAN 216, and / or using assistance data provided to the UE 105, e.g., by the LMF 220). The UE 105 can additionally transmit uplink reference signals, sometimes referred to as uplink PRS or UL Sounding Reference Signals (SRS) for positioning, which can be received by wireless nodes such as the gNBs 210, ng-eNB 214, and / or the WLAN 216, and can be referred to as uplink SRS (UL-SRS) or UL-PRS. The UE 105 can additionally transmit sidelink reference signals, such as SL PRS or SL Channel State Information Reference Signals (SL CSI-RS), which can be received by a sidelink UE 105a.It will be appreciated that PRS, SRS and CSI-RS are examples of reference signals that can be used for positioning, but other reference signals can also be used if desired.

[0066] Gateway mobile location center (GMLC) 225 can support location requests for UE 105 received from external client 230 and can forward such location requests to AMF 215 for forwarding by AMF 215 to LMF 220 or can forward location requests directly to LMF 220. Location responses from LMF 220 (e.g., containing a location estimate for UE 105) can similarly be returned to GMLC 225 either directly or via AMF 215, and GMLC 225 can then return the location response (e.g., containing the location estimate) to external client 230. GMLC 225 is shown connected to AMF 215 and LMF 220 in Figure 2 AMF 215 and LMF 220 in some implementations, 5G CN 240 can only support one of these connections.

[0067] As further shown in Figure 2 As further shown in Figure 2Further shown, LMF 220 and UE 105 can communicate using the LPP protocol. LMF 220 and UE 105 can also or instead communicate using the LPP protocol (in NR, can also be referred to as NRPP or NPP). Herein, LPP messages can be transferred between UE 105 and LMF 220 via AMF 215 and serving gNB 210-1 or serving ng-eNB 214 for UE 105. For example, LPP messages can be transferred between LMF 220 and AMF 215 using messages based on service-based operations (e.g., based on Hypertext Transfer Protocol (HTTP)), and LPP and / or LPP messages can be transferred between AMF 215 and UE 105 using 5G NAS protocols. LPP and / or LPP protocols can be used to support positioning of UE 105 using UE-assisted and / or UE-based positioning methods such as A-GNSS, RTK, OTDOA, and / or Enhanced Cell ID (ECID). LPPa protocols can be used to support positioning of UE 105 using network-based positioning methods such as ECID (e.g., when used with measurements obtained by gNB 110 or ng-eNB 214), and / or can be used by LMF 220 to obtain location-related information from gNBs 210 and / or ng-eNBs 214, e.g., parameters defining DL-PRS transmissions from gNBs 210 and / or ng-eNBs 214.

[0068] In the case of UE 105 accessing WLAN 216, LMF 220 can use LPPa and / or LPP to obtain a location of UE 105 in a similar manner as just described for UE 105 accessing gNB 210 or ng-eNB 214. Thus, LPPa messages can be transferred between WLAN 216 and LMF 220 via AMF 215 and N3IWF 250 to support network-based positioning of UE 105 and / or transfer of other location information from WLAN 216 to LMF 220. Alternatively, LPPa messages can be transferred between N3IWF 250 and LMF 220 via AMF 215 to support network-based positioning of UE 105 based on location-related information and / or location measurements known or accessible to N3IWF 250 and transferred from N3IWF 250 to LMF 220 using LPPa. Similarly, LPP and / or LPP messages can be transferred between UE 105 and LMF 220 via AMF 215, N3IWF 250, and serving WLAN 216 for UE 105 to support UE-assisted or UE-based positioning of UE 105 by LMF 220.

[0069] With a UE-assisted positioning method, the UE 105 can obtain location measurements and send the measurements to a location server (e.g., LMF 220) for computation of a position estimate for the UE 105. The location measurements can include one or more of a received signal strength indication (RSSI), RTT, reference signal received power (RSRP), reference signal received quality (RSRQ), time of arrival (ToA), AoA, differential AoA (DAoA), AoD, or timing advance (TA) for one or more access points of gNBs 210, ng-eNB 214, and / or WLANs 216. The location measurements can also or instead include measurements of RAT-independent positioning methods, such as GNSS (e.g., GNSS pseudoranges, GNSS code phases, and / or GNSS carrier phases for GNSS satellites 110), WLAN, etc. With a UE-based positioning method, the UE 105 can obtain location measurements (which can be the same as or similar to the location measurements for a UE-assisted position method) and can further compute a position for the UE 105 (e.g., with the aid of assistance data received from a location server such as LMF 220 or broadcast by gNBs 210, ng-eNB 214, or WLANs 216). With a network-based positioning method, one or more base stations (e.g., gNBs 210 and / or ng-eNB 214), one or more APs (e.g., in WLANs 216), or N3IWF 250 can obtain location measurements (e.g., measurements of RSSI, RTT, RSRP, RSRQ, AoA, or ToA) for signals sent by the UE 105 and / or, in the case of N3IWF 250, can receive measurements obtained by the UE 105 or by an AP in a WLAN 216, and can send the measurements to a location server (e.g., LMF 220) for computation of a position estimate for the UE 105.

[0070] In the 5G NR positioning system 200, some of the position measurements (e.g., AoA, AoD, ToA) made by the UE 105 can use RF reference signals received from the base stations 210 and 214. These signals can include PRS, which can be used, for example, to perform TDOA, AoD, and RTT-based positioning of the UE 105. Other reference signals that can be used for positioning can include cell-specific reference signals (CRS), channel state information reference signals (CSI-RS), synchronization signals (e.g., synchronization signal block (SSB) synchronization signals (SS)), and the like. Moreover, the signals can be transmitted in Tx beams (e.g., using beamforming techniques), which can impact angle measurements, such as AoD. Additionally or alternatively, the UE 105 can transmit uplink reference signals, such as UL-SRS, which are received by the base stations 210 or 214 for positioning, such as TDOA, AoA, and RTT. For example, 5G NR supports 5G local positioning techniques including DL-only, UL-only, and a combination of DL and UL (DL+UL) positioning methods. For example, DL-based positioning techniques include DL time difference of arrival (DL-TDOA) and DL angle of departure (DL-AoD). UL-based positioning techniques include UL time difference of arrival (UL-TDOA) and UL angle of arrival (UL-AoA). A combination of DL and UL (DL+UL) based positioning techniques includes round trip time (RTT) with one or more neighboring base stations (multi-RTT). Moreover, 5G NR Rel-16 also supports enhanced cell identification (E-CID) based on radio resource management (RRM) measurements. Additionally or alternatively, the UE 105 can transmit sidelink reference signals, such as SL-PRS, which are received by a sidelink UE 105a and used for positioning.

[0071] Figure 3 is a diagram illustrating a simplified environment 300 that includes two base stations 120-1 and 120-2 (which can correspond to Figure 1 the base stations 120 of Figure 2gNB 210 and / or ng-eNB 214) and UE 105. For each beam sweep, which can repeat periodically, each directional beam is rotated, e.g., 120 degrees or 360 degrees. Each directional beam can include an RF reference signal (e.g., a PRS resource), where base station 120-1 produces a set of RF reference signals including Tx beams 305-a, 305-b, 305-c, 305-d, 305-e, 305-f, 305-g, and 305-h, and base station 120-2 produces a set of RF reference signals including Tx beams 309-a, 309-b, 309-c, 309-d, 309-e, 309-f, 309-g, and 305-h. Because UE 105 can also include an antenna array, UE 105 can receive the RF reference signals transmitted by base stations 120-1 and 120-2, using beamforming to form respective receive beams (Rx beams) 311-a and 311-b. Beamforming in this way (by base stations 120 and optionally by UE 105) can be used to make communications more efficient. They can also be used for other purposes, including making AoD measurements.

[0072] AoD can be measured when base stations 120 transmit reference signals using beam sweeping in each of multiple directions using a respective plurality of beams (e.g., beams 309-a through 309-f). By measuring the RSRP of each reference signal at UE 105, the beam 309 that is most aligned with UE 105 can be identified (as the beam with the highest value). Additional techniques can be performed to determine an accurate AoD based on the alignment. For UE-based positioning, UE 105 can be provided information about each beam 309 (e.g., beam width and boresight) to allow the UE to compute the AoD. Alternatively, for UE-assisted positioning, the UE can provide RSRP measurements to a positioning server 160 (e.g., which can be in NG-RAN 235 or which can be in LMF 220), which can use the RSRP measurements and beam information to compute the AoD.

[0073] An example of a combination of DL and UL (DL+UL) based positioning technologies is round-trip time (RTT) with one or more neighboring base stations (multi-RTT). In multi-RTT, UE 105 receives DL reference signals from multiple TRPs (e.g., gNB 220) and sends UL reference signals to multiple TRPs. UE 105 measures the Rx-Tx of the DL reference signals received from the multiple TRPs (e.g., gNB 220) and the UL reference signals sent to the TRPs, and the TRPs measure the Rx-Tx of the UL reference signals received from UE 105 and the DL reference signals sent to UE 105. The Rx-Tx measurement can be used to determine the RTT between UE 105 and each TRP, which can be used by the positioning engine to estimate the location of the UE, for example, at location server 160 (e.g., in NG-RAN 235 or LMF 220) or at UE 105. The bidirectional process performed for RTT avoids the need for network synchronization, such as Time Difference of Arrival (TDOA), found in DL-only or UL-only positioning technologies.

[0074] Figure 4A Figure 400 illustrates exemplary timing within RTT measurements during wireless probe requests and responses. Figure 4A In the diagram, the vertical axis represents the straight-line distance D between entity 1 and entity 2, while the horizontal axis from left to right represents time. Entity 1 and entity 2 are the initiating entity and the responding entity, respectively. In a network-centric implementation, entity 1 may correspond to a TRP (e.g., a base station such as gNB 220), and entity 2 may correspond to UE 105. In a UE-centric implementation, entity 1 may correspond to UE 105, and entity 2 may correspond to a network node (e.g., a base station such as gNB 220).

[0075] To determine the RTT (and distance) between Entity 1 and Entity 2, Entity 1 sends an RTT measurement (RTTM) signal at a first time (referred to as "t1"). After some propagation time, Entity 2 detects the RTTM signal at a second time (referred to as "t2"). Entity 2 spends time processing the received RTTM signal before sending an RTT response (RTTR) signal at a third time (referred to as "t3"). After some propagation time, Entity 1 detects the received RTTR signal at a fourth time (referred to as "t4"). Entity 1 performs an Rx-Tx measurement 402 between sending the RTTM and receiving the RTTR signal (i.e., t4-t1), while Entity 2 performs an Rx-Tx measurement 404 between receiving the RTTM and sending the RTTR signal (i.e., t3-t2). Entity 2 may send the Rx-Tx measurement 404 to Entity 1 (and vice versa), or both may send their respective measurements to a location server. The measured time of flight, or RTT, can be determined as follows:

[0076] The measured RTT = (t4 - t1) - (t3 - t2). Equation 1

[0077] However, in order to transmit digital signals, the Tx RF chain (also known as the RF front-end (RFFE)) at the transmitting device performs the process of converting the digital signal into an RF signal. For example, the Tx RF chain of the transmitting device may include a digital-to-analog converter (DAC) to convert the digital signal into a baseband (BB) analog signal, an up-converter to up-convert the baseband signal into an RF signal, and a power amplifier (PA) to amplify the RF signal, which is then radiated from the transmitting device's antenna (Ant). Similarly, the receiving device may include an Rx RF chain to perform the reverse process to retrieve the original digital signal from the arriving RF signal. For example, the Rx RF chain of the receiving device may include: filters (e.g., low-pass, high-pass, band-pass) to filter the RF signal received by the receiving device's antennas (multiple) (Ant); a low-noise amplifier (LNA) to amplify the filtered RF signal; a down-converter to down-convert the filtered RF signal into a baseband (BB) signal; and an analog-to-digital converter (ADC) to recover the digital signal from the baseband (BB) signal.

[0078] The process of converting a digital signal into an RF signal, performed by the Tx RF chain of the transmitting device, requires a finite amount of time (generally referred to as the "Tx group delay"). The reverse process of recovering the digital signal from the RF signal, performed by the Rx RF chain of the receiving device, also requires a finite amount of time (generally referred to as the "Rx group delay").

[0079] Therefore, as Figure 4A As shown, times t1, t2, t3, and t4 are the times measured in the digital domain by entities 1 and 2. The RTTM signal actually leaves the antenna (Ant) of entity 1 at some time after t1 (referred to as "t1") and arrives at the antenna (Ant) of entity 2 at some time before t2 (referred to as "t2"). Similarly, the RTTR signal leaves the antenna (Ant) of entity 2 at some time after t3 (referred to as "t3") and arrives at the antenna (Ant) of entity 1 at some time before t4 (referred to as "t4"). The Tx group delay is shown as the delay between the measured transmission time of the signal and the actual time the signal leaves the antenna (e.g., t1'-t1 for entity 1 and t3'-t3 for entity 2), while the Rx group delay is shown as the delay between the actual arrival time of the signal at the antenna and the measured reception time of the signal (e.g., t2-t2' for entity 2 and t4-t4' for entity 1). Therefore, the actual flight time, or RTT, is as follows:

[0080] Actual RTT = (t4' - tl') - (t3' - t2'). Equation 2

[0081] The distance D between the transmitter and receiver can be determined from a measured RTT based on the speed of a radio wave (i.e., the speed of light c), e.g., D = (measured RTT / 2) * c. Using measured RTTs from multiple base stations (e.g., multi-cell RTT) and known locations of the base stations, the location of the UE can be determined using multilateration.

[0082] However, as Figure 4A shown, the measured RTT can differ from the actual RTT due to group delay, and thus, location determination of the UE using RTT (e.g., using multi-cell RTT) can suffer from group delay related errors.

[0083] Figure 4B A simplified environment 450 and exemplary techniques for using a differential approach to eliminate UE-based group delay related errors for determining the location of UE 105 are shown. For example, Figure 4B A differential RTT measurement is used to eliminate UE-based group delay errors in location determination is shown. With differential RTT, RTT measurements can be performed to generate the distance between UE 105 and each of base stations 452-1, 452-2, and 452-3 (sometimes collectively referred to as base stations 452), e.g., in Figure 4B , shown as dl, d2, and d3, respectively. However, as noted above, the ranges dl, d2, and d3 are based on measured RTT, not actual RTT, which differs due to group delay. The difference in measured RTT (or equivalently, the determined distances) cancels out the UE-based group delay, and thus, can be used for positioning when there can be un-calibrated UE-based group delay.

[0084] Figure 4B The differential RTT for base stations 452-1 and 452-2 in Figure 4B is based on the difference between the measured RTT for reference base station 452-1 and base station 452-2 (e.g., equivalent to the difference between distances dl and d2, respectively), and UE 105 is located on a hyperbola 554 shown in Figure 4B . A similar determination is made for the difference between the measured RTT for reference base station 452-1 and base station 452-3 (e.g., equivalent to the difference between distances dl and d3, respectively), and UE 105 is located on a hyperbola 556 shown in Figure 4B . For example, the hyperbolas 554 and 556 can be determined as the set of all points that have the same difference between the RTT measurements at each focus, i.e., the known locations of the base stations. Then,The intersection of the two hyperbolas at the midpoint 558 determines the two-dimensional location of the UE 105 (although typically more pairs of hyperbolas from RTT measurements from more base stations will be obtained to resolve ambiguities and reduce the location error of the UE 105). In the case of three-dimensional positioning, the hyperbolas are replaced by hyperboloids obtained by rotating the hyperbola about an axis passing through the focus, and the location of the UE is obtained as the intersection of these hyperboloids.

[0085] The use of differential RTT establishes robustness to changes in group delay by sacrificing one observation (e.g., a reference RTT measurement) because the differential RTT uses the difference between RTTs (or equivalently, distances) rather than the absolute distance. Depending on the number of individual RTT measurements available, it can be acceptable to lose one observation (reference RTT measurement) in order to reduce the error from the UE- based group delay. The use of the differential approach can be selected by the positioning engine, e.g., in the UE 105 or the location server 160, e.g., which can be in the NG-RAN 235 or can be the LMF 220, based on whether the group delay in the UE has been calibrated, for example. With UE-based positioning, the UE 105 can select the differential approach if the group delay in the UE has not been calibrated, for example. In UE-assisted positioning (e.g., with the location engine in a gNB or location server), the UE can indicate whether the group delay in the UE has been calibrated, and the positioning engine can select the differential approach if the group delay in the UE has not been calibrated.

[0086] Network-based positioning of a UE, such as RTT or differential RTT discussed above, can often require the UE to communicate with multiple base stations. For example, in RTT-based positioning, an RTT measurement can involve transmitting and receiving wireless reference signals with multiple base stations, and further reporting Rx-Tx time difference measurements to a serving base station. For many types of UEs, such as mobile phones, the power requirements of RTT-based positioning can not be a problem. However, for “lightweight” UEs, which typically have tighter power budgets, these types of communications can be problematic.

[0087] As used herein, the term “light” or “low-tier” UE or device refers to a wireless device that has a relatively lower operating bandwidth as compared to an “advanced” UE or device that has a relatively higher operating bandwidth. A light UE can also be referred to as a “reduced capability” UE. For reduced capability devices in 5G NR, 3GPP is developing a “NR Light” standard that allows NR devices to meet higher latency and data rate requirements in a 5G NR environment with reduced complexity and energy consumption (as compared to Narrowband IoT (NB-IoT) or LTE-M in LTE environments). Thus, references herein to light or low-tier UEs, which can sometimes be referred to as RedCap UEs or devices, can refer to 5G NR devices that use NR Light, and references herein to advanced UEs or devices can refer to 5G NR devices that use standard NR. Examples of light UEs can include wearable devices (e.g., smart watches), relaxed / narrowband IoT devices, low-end mobile phones, etc. Current operating bandwidths for these devices are on the order of 5-20 megahertz (MHz), although some low-tier UEs can have higher or lower operating bandwidths. Examples of advanced UEs can include high-end mobile phones (e.g., smartphones), tablets, vehicles, etc. Advanced UEs currently operate at 100 MHz or higher bandwidths. Generally speaking, light UEs have a relatively lower bandwidth (e.g., less than 100 MHz), lower processing capability, and / or lower power budget as compared to advanced UEs.

[0088] As noted above, network-based positioning generally requires communication with multiple base stations. For example, high-precision positioning determinations (e.g., with 3 m or less accuracy) generally require multi-RTT, with RTT measurements between a UE and multiple base stations. However, the power requirements for communicating with multiple base stations is generally burdensome for light UEs. Moreover, light UEs can not be able to obtain reference signals (e.g., PRSs) from multiple base stations due to antenna losses, low bandwidth, fewer antennas, and reduced baseband capabilities as compared to advanced UEs. Furthermore, light UEs have reduced transmit power, which can result in lower quality uplink (UL) measurements at base stations of RF signals transmitted by light UEs.

[0089] To reduce the power requirements on UEs, techniques can be used in which the position of a light UE can be determined with high precision using fewer base stations (e.g., a single base station). This is achieved by leveraging one or more advanced UEs that have known locations. Such positioning techniques can use UE-assisted and UE-based positioning.

[0090] Figure 5is a simplified diagram illustrating network-based position determination of a light UE 510 using a single base station 120 (e.g., the serving base station of the light UE 510 and / or advanced UE 520). Positioning of the light UE 510 is achieved using communications between the light UE 510 and the advanced UE 520, where both the light UE 510 and the advanced UE 520 receive reference signals 550, 560 from the base station 120. Such positioning can be facilitated by using a location server 160, e.g., in the NG-RAN 235 or LMF 220.

[0091] The position of the light UE 510 can be mathematically determined by solving for the distance R T of the light UE 510 from the base station 120 T and the differential angle Q T between the AoD f2 and the AoD f1, which are the AoDs of the advanced UE 520 and the light UE 510, respectively (i.e., Q T = f2 - R1). It can be noted that the baseline from which the AoDs f1 and f2 are measured can be measured from true north, or any coordinate system used for positioning by the network (e.g., geographic coordinates, East-North-Up (ENU), etc.). The solving for these two variables can be done with the help of the advanced UE 520, which can measure the reference signal 560 as well as the sidelink signal 570 provided by the light UE 510 in response to the light UE receiving the reference signal 550.

[0092] This distance R T may be determined based on the time difference of the reception of the reference signal 560 and the sidelink signal 570 at the advanced UE 520. Where R sum is the distance R T and the distance R R between the light UE 510 and the advanced UE 520, then R T is solved to give the following expression:

[0093] R T = R sum - R R . Equation 3

[0094] If L is defined as the distance between the base station 120 and the advanced UE 520, then Equation 3 can be modified as follows:

[0095]

[0096] Because the location of the advanced UE 520 is known (or can be predetermined), the distance L and angle θ can be obtained based on the location of the advanced UE and the known location of the base station 120 (e.g., from the location server 160 and / or the base station location almanac stored in the advanced UE 520). R Furthermore, θ can be determined from the AoD measurement of the reference signal transmitted by base station 120. T (It may differ from the method used to determine distance R) T (Reference signal 550). For example, AoDθ from base station 120. T This can be determined based on RSRP measurements reported by the lightweight UE 510. Therefore, once R... sum Then we can use Equation 4 to determine the range R. T .

[0097] To solve R sum The embodiment can determine the time difference between receiving reference signal 550 at lightweight UE 510 and receiving reference signal 560 at advanced UE 520. Sidelink signal 570 transmitted from lightweight UE 510 to advanced UE 520 can be triggered by receiving reference signal 550 at lightweight UE 510, and the sidelink connection can also be used to relay the time of receiving reference signal 550 at lightweight UE 510 to advanced UE 520. Figure 6 The document provides an explanation of this.

[0098] Figure 6 The time-distance graph according to the embodiment shows that in Figure 5 How can timing be used to determine R in the configuration shown? sum Here, base station 120 transmits reference signals 550 and 560 (e.g., DL-PRS), which are received by both lightweight UE 510 (which receives reference signal 550 first) and advanced UE 520. Figure 6 The different angles of the reference signal at 550° and 560° reflect Figure 5 Different paths for reference signals 550 and 560.

[0099] As explained in further detail below, reference signal 550 and reference signal 560 may include the same or different reference signals. (Because) Figure 6 Reference signals 550 and 560 are shown to be transmitted simultaneously, which would reflect the transmission of a single reference signal. However, the embodiment is not limited to this. Location server 160 can coordinate the transmission and measurement of the reference signals(multiple) by providing information to base station 120 about how to transmit the reference signals(multiple), and providing information to lightweight UE 510 and advanced UE 520 about when to measure the reference signals(multiple).

[0100] Since the reference signal propagates at a speed close to the speed of light c, R sum The value can be determined by the following formula:

[0101] R sum =(T Rx_sidelink -T Rx_RS -T UE_Rx→Tx Equation 5

[0102] Among them, T Rx_sidelink It is the time (ToA) during which the advanced UE receives the sidelink signal 570. Rx_RS It is the time (ToA) when the advanced UE receives the reference signal 560, and T UE_Rx→Tx The lightweight UE 510 receives reference signal 550(T) UE_Rx_RS The time (ToA) and the light UE 510 transmit sidelink signals 570 (T) Tx_sidelink The time difference between the departure time (ToD) and the arrival time (i.e., the departure time). Using R sum The value of distance R can be determined according to Equation 4 above. T And it can be based on distance R T Angle θ T The location of the lightweight UE 510 is determined by the location of base station 120. Because R sum The value is based on the difference between the time when the lightweight UE 510 and the advanced UE 520 receive reference signals 550 and 560, so synchronization is not required between the lightweight UE 510, the advanced UE 520, or the base station 120 to perform positioning of the lightweight UE 510 using the techniques described herein.

[0103] As described above, depending on the desired function, a single reference beam can be used to determine the range R. sum , such as regarding Figure 5 and Figure 6 As stated above. Figure 7A and Figure 7B An example of it is shown.

[0104] Figure 7A and Figure 7B It is similar to Figure 5 The diagrams of base station 120, lightweight UE 510, and advanced UE 520 shown are provided to illustrate how beams can be used differently in different embodiments and / or situations according to the desired functionality. For example, in Figure 7A In this context, the single reference signal beam 710 is wide enough to be received by both the lightweight UE 510 and the advanced UE 520, thus allowing it to be used for determining R as previously described. sumThe process. It can be seen that whether the reference signal beam 710 is wide enough depends not only on the width of the reference signal beam, but also on how close the lightweight UE 510 and the advanced UE 520 are to each other. (For example, in some cases, the lightweight UE 510 and the advanced UE 520 can be close enough that both the lightweight UE 510 and the advanced UE 520 can use relatively narrow beams, for example, as...) Figure 7B (As shown.) However, in Figure 7B In this configuration, the lightweight UE 510 is aligned with the first reference signal beam 710, while the advanced UE 520 is more closely aligned with the second reference signal beam 730. In this case, even if the advanced UE 520 can detect both the first and second reference signal beams 720 and 730, it may still perform a ToA measurement on the second reference signal beam 730 instead of the first reference signal beam 720 (e.g., due to a more favorable SNR value). Although the reference signal beams 720 and 730 can be transmitted at different times, since the transmission time difference between the first and second reference signal beams 720 and 730 is known, this time difference can be considered in Equation 5, thus allowing for the determination of R when using different reference signal beams transmitted at different times. sum .

[0105] Therefore, it can be based on distance R T Angle θ T The location of the lightweight UE 510 is determined by the location of base station 120. This technique does not require transmitting the UL reference signal from the lightweight UE 510 to base station 120, which is effective for power-constrained UEs (such as the lightweight UE 510). Furthermore, similar to RTT-based positioning, network synchronization is not required. Additionally, using a single base station for positioning is advantageous in situations with limited cell coverage, such as potential scenarios for NR lightweight UE positioning.

[0106] exist Figure 5 In the positioning technology shown, the lightweight UE 510 is required to report the Rx-Tx time difference between its received reference signal 550 and the transmitted sidelink signal 570, i.e. Figure 6 The T shown UE_Rx→Tx Therefore, similar to Figure 4A The hardware group delay in the lightweight UE 510, as discussed in the RTT-based technology, can affect positioning performance, especially if the UE group delay is not properly calibrated. Specifically, in some cases, due to lower operating bandwidth and lower-cost UE implementations, group delay calibration capabilities may be reduced, which could affect positioning performance. Figure 5 The UE positioning of the single base station technology is shown.

[0107] However, Figure 5 The localization method shown can be extended to cases with multiple anchor UEs, where multiple sidelink signals are transmitted between the lightweight UE and multiple anchor UEs (e.g., advanced UEs) to achieve UE localization based on time-domain measurements. To overcome the UE group delay problem, differential R... sum method

[0108] Figure 8 This is a simplified diagram illustrating network-based location determination of a target UE 810 using a single base station 802, which is consistent with... Figure 5 The diagram is similar, but uses multiple sidelink UEs 820a, 820b, and 820c (sometimes collectively referred to as sidelink UE 820 or sidelink UE 820i, where i = a, b, and c). The target UE 810 can be, for example... Figure 1 and Figure 2 The UE shown is 105 or 105a, and in some embodiments may be a lightweight UE. The sidelink UE 820 acts as an anchor UE and may be, for example... Figure 1 and Figure 2 The UE shown is 105a or 105, and in some implementations may be an advanced UE. Base station 802 may be, for example, an eNB or gNB, such as... Figure 2 The gNB 210 or ng-eNB 214 shown are examples. In some implementations, an access point (e.g., Figure 1 Access point 130 (shown in the diagram) replaces base station 802. The location of target UE 810 is achieved using one or more reference signals (e.g., reference signals 860a, 860b, and 860c (sometimes collectively referred to as reference signal 860 or reference signal 860i, where i = a, b, and c)) transmitted by base station 802 and received by target UE 810 and received by sidelink UE 820, as well as sidelink communication between target UE 810 and sidelink UE 820. The location determination of target 810 can be facilitated by using location server 804, for example, in NG-RAN 235 or LMF 220.

[0109] During operation, Figure 8 The positioning technology shown is similar to Figure 5The illustrated positioning techniques, however, use multiple anchor UEs (sidelink UEs 820). For example, the base station 802 transmits one or more reference signals 850 and 860, e.g., DL PRSs, which are received by the target UE 810 and each of the sidelink UEs 820. In response to receiving the reference signals 850, the target UE 810 transmits one or more sidelink reference signals 870a, 870b, and 870c to the sidelink UEs 820a, 820b, and 820c, respectively. The sidelink reference signals 870a, 870b, and 870c (sometimes collectively referred to as sidelink reference signals 870 or sidelink reference signals 870i, where i = a, b, and c) can include the same or different sidelink reference signals and can be, e.g., SL-PRSs.

[0110] The target UE 810 measures a plurality of Rx-Tx time differences between reception of the reference signals 850 (i.e., measured ToA) and transmission of each of the sidelink reference signals 870a, 870b, and 870c (i.e., measured ToD), e.g., T UE_Rx→Tx_a , T UE_Rx→Tx_b , T UE_Rx→Tx_c . The target UE 810 can report the Rx-Tx time differences (e.g., T UE_Rx→Tx_i , where i = a, b, and c) to the location server 804 or can retain the Rx-Tx time differences (T UE_Rx→Tx_i ) for further processing. In each Rx-Tx time difference (T UE_Rx→Tx_i ) report, the target UE 810 can include the TRP ID, the reference signal ID (e.g., PRS ID), the sidelink reference signal ID (e.g., SL-PRS ID), the UE ID that transmitted the sidelink reference signal, and the UE ID that received the corresponding sidelink reference signal. The target UE 810 can also include a timestamp associated with each Rx-Tx time difference (T UE_Rx→Tx_i in the report.

[0111] The sidelink UEs 820 receive the reference signals 860 from the base station 802 and the sidelink reference signals 870 from the target UE 810. Each of the sidelink UEs 820a, 820b, 820c measures a time difference between reception of the reference signals 860 and the sidelink reference signals 870, e.g., T Rx_sidelink_a -T Rx_RS_a , T Rx_sidelink_b -T Rx_RS_b , T Rx_sidelink_c -T Rx_RS_c . The sidelink UEs 820 can report the measured time differences (e.g., T Rx_sidelink_i -T Rx_RS_iWhere i = a, b, and c). During the time difference of measurement (e.g., T... Rx_sidelink_i -T Rx_RS_i In the report, each sidelink UE 820 may include a TRP ID, a reference signal ID (e.g., PRS ID), a sidelink reference signal ID (e.g., SL-PRSID), the UE ID that transmitted the sidelink reference signal, and the UE ID that received the corresponding sidelink reference signal. Each sidelink UE 820 may also include in the report the time difference with the measured time (e.g., T...). Rx_sidelink_i -T Rx_RS_i The associated timestamp.

[0112] The location of the target UE 810 can be based on the distance to multiple sidelink UEs 820 and R. sum The difference between them is determined mathematically. Each distance and R... sum_i (where i = a, b, and c) is the distance R between the base station and the target UE 810. T Distance R between target UE 810 and sidelink UE 820i R_i The combined distance, for example,

[0113] R sum_i =R T +R R_i Equation 6

[0114] It can be based on the Rx-Tx time difference (T) measured by the target UE 810. UE_Rx→Tx_i ) and the measurement time difference (e.g., T) measured by each sidelink UE 820. Rx_sidelink_i -T Rx_RS_i To determine the distance and R sum_i Since the reference signal propagates at a speed close to the speed of light c, the distance and R... sum_i The value can be determined by the following formula:

[0115] R sum_i =(T Rx_sidelink_i -T Rx_RS_i -T UE_Rx→tx_i )*c+L i Equation 7

[0116] Among them, T Rx_sidelink_i It is the time (ToA) during which the sidelink UE 820i receives the sidelink signal 870i. Rx_RS_i It is the time (ToA) at which the side-link UE 820i receives the reference signal 860i, T UE_Rx→Tx_i L is the time difference between the time when the target UE 810 receives the reference signal 850 (ToA) and the time when the target UE 810 transmits the sidelink signal 870i. iis the distance between the base station 802 and the UE 820i, which is known (or can be determined a priori).

[0117] In one implementation, each distance and Rsum_i sum_i may be determined by the location server 804, e.g., where the target UE 810 reports the Rx-Tx time difference (e.g., T UE_Rx→Tx_i ) to the location server 804, and each sidelink UE 820 reports the time difference (T Rx_sidelink_i- T Rx_RS_i ) to the location server 804. Rx_sidelink_i- T Rx_RS_i .

[0118] The differential distances and R sum_diff may be determined for the plurality of sidelink UEs 820 based on the Rx-Tx time difference (e.g., T UE_Rx→Tx_i ) measured by the target UE 810 and the time difference (T Rx_sidelink_i- T Rx_RS_i ) measured by the sidelink UE 820i.

[0119] Each differential distance and R sum_diff_j is the difference between the distance sum (R sum_Ref ) for a reference sidelink UE from the plurality of sidelink UEs 820 and the distance sum (R sum_j ) for another sidelink UE, where represents each remaining sidelink UE in the plurality of sidelink UEs,

[0120] R sum_diff_j = R sum_Ref - R sum_j . Equation 8

[0121] For example, considering sidelink UE 820a as the reference sidelink UE, the differential distance and R sum_diff_b is the difference between the distance sum (e.g., distance sum R sum_diff_a ) for the sidelink UE 820a and the distance sum (e.g., distance sum R sum_diff_b ) for the sidelink UE 820b, while the differential distance and R sum_diff_c is the difference between the distance sum (e.g., distance sum R sum_diff_a ) for the sidelink UE 820a and the distance sum (e.g., distance sum R sum_diff_cThe difference between the reference sidelink UE and the reference sidelink UE can be based on side information, such as RSRP, or other parameters such as RSSI, RSRQ, SNR, etc. The differential distance and R are determined by the location server 804. sum_diff_i In this case, the target UE 810 can send RSRP or other parameter measurements to the location server 804 to help select the reference sidelink UE.

[0122] Each difference distance and R sum_diff_j A hyperbola is defined that can be determined as the set of all points whose distances to each focus have the same difference, i.e., the known locations of the reference side-link UE and the other side-link UE. For example, as... Figure 8 As shown, the difference distance and R sum_diff_b The hyperbola 852, difference distance, and R are defined. sum_diff_b Hyperbola 854 has been defined. Then, it can be used... Figure 8 The two-dimensional position of UE 810 is determined by the intersection of the two hyperbolas at point 856 (although more hyperbolas can be obtained from the distances and measurements of more side-link UEs if needed to eliminate ambiguity and reduce the position error of UE 810). In the case of three-dimensional positioning, the hyperbolas are replaced with hyperboloids obtained by rotating the hyperbolas around an axis passing through the focus, and the position of the UE is obtained as the intersection of these hyperboloids.

[0123] In the UE-assisted positioning process based on differential distance sums, the location server 804 uses differential distance sums and R... sum_diff_i To determine the location of the target UE 810. In some implementations, the location server 804 may receive the time difference (e.g., T) from the sidelink UE 820. Rx_sidelink_i -T Rx_RS_i ) and the Rx-Tx time difference (e.g., T) measured from the target UE 810. UE_Rx→Tx_i Location server 804 can also receive the location of the sidelink UE 820. Location server 804 can be based on time difference (e.g., T). Rx_sidelink_i -T Rx_RS_i ) and the measured Rx-Tx time difference (e.g., T UE_Rx→Tx_i To determine the distance and R sum_i Then, before determining the location of the target UE 810, the differential distance and R are determined. sum_diff_i In some implementations, the sidelink UE 820 may report its time difference (e.g., T) to the target UE 810, for example, via sidelink communication. Rx_sidelink_i -T Rx_RS_i ), and the target UE 810 can be based on a time difference (e.g., T). Rx_sidelink_i -T Rx_RS_i) and the measured Rx-Tx time difference (e.g., T UE_Rx→Tx_i ) to determine the distance and R sum_i . The target UE 810 can determine the differential distance and R sum_i based on the distance and R sum_diff_i . The location server 804 can receive the differential distance and R sum_diff_i from the target UE 810 and determine the location of the target UE 810. In some implementations, the location server 804 can receive the distance and R sum_i from the target UE 810 and determine the differential distance and R sum_diff_i before determining the location of the target UE 810.

[0124] In a UE-based positioning procedure based on differential distance and, the target UE 810 determines the location of the target UE 810 based on the differential distance and R sum_diff_i and assistance data including the location of the base station 802 and the location of the sidelink UE 820. The assistance data can be provided by the location server 804 and / or the sidelink UE 820. For example, the sidelink UE 820 can provide their location to the target UE 810 in a sidelink communication or via the location server. In some implementations, the target UE 810 can receive the time difference (e.g., T Rx_sidelink_i -T Rx_RS_i ) from the sidelink UE 820, e.g., via a sidelink communication, and the target UE 810 can determine the distance and R Rx_sidelink_i based on the time difference (e.g., T Rx_RS_i -T UE_Rx→Tx_i ) and the measured Rx-Tx time difference (e.g., T sum_i ) and then determine the differential distance and R sum_diff_i before determining the location of the target UE 810. In some implementations, the sidelink UE 820 can report their time difference (e.g., T Rx_sidelink_i -T Rx_RS_i ) to the location server 804, and the target UE 810 can receive the time difference (e.g., T Rx_sidelink_i -T Rx_RS_i ) from the location server 804, and the target UE 810 can determine the distance and R Rx_sidelink_i based on the time difference (e.g., T Rx_RS_i -T UE_Rx→Tx_i ) and the measured Rx-Tx time difference (e.g., T sum_i ) and then determine the differential distance and R sum_diff_j before determining the location of the target UE 810.

[0125] The differential distance and R sum_diff_iThe use of this method advantageously eliminates the need for the differential angle θ measured based on AoDφ2 and AoDφ1 mentioned in Equation 4. T The need for this. Furthermore, the differential distance and R... sum_diff_i The use of differential distance sums effectively eliminates target UE group delay from the localization process. Therefore, the use of differential distance sums establishes robustness to group delay variations. The use of a differential scheme can be selected by the localization engine based on whether the group delay in the UE has been calibrated; for example, this localization engine may be in UE 105 or location server 804, such as in NG-RAN 235 or LMF 220. For example, for UE-based localization, target UE 810 can select whether to use differential distance sums based at least in part on its group delay calibration status. sum_diff_j For example, if the group delay in the UE has not been adequately calibrated or has not been calibrated recently, a differential scheme can be used. Similarly, for UE-assisted positioning, the location server 804 can also select whether to use differential distance and R based at least in part on the group delay calibration status of the target UE 810. sum_diff_j The calibration status of this group delay can be provided to the location server 804 by the target UE 810. For example, the target UE 810 can provide the location server 804 with an indication of whether it has been calibrated. In some implementations, the target UE 810 can report its calibration error statistics, such as the mean and variance of the calibration error. The calibration status report from the target UE 810 to the location server 804 can be periodic or aperiodic, which can be triggered by an event such as a change in UE temperature.

[0126] Figure 9 This is a call flowchart illustrating an embodiment of a UE-based location process that uses differential distances determined for multiple side-link UEs 820a, 820b, and 820c (sometimes collectively referred to as side-link UE 820 or side-link UE 820i, where i = a, b, and c) to determine the location of a target UE 810, as shown below. Figure 8 As shown. Figure 8 As discussed in the document, the target UE 810 can correspond to Figure 1 and Figure 2 The UE shown is 105 or 105a, and in some implementations may be a lightweight UE. The sidelink UE 820 acts as an anchor UE and may correspond to... Figure 1 and Figure 2 The UE shown is either UE 105a or 105, and in some embodiments may be an advanced UE. Base station 802 may correspond to... Figure 1 One of the base station 120 or access point 130 shown, and can be, for example, an eNB or gNB, such as Figure 2the gNB 210 or ng-eNB 214 shown. The location server 804 can correspond to Figure 1 the location server 160 shown, which in some implementations can be the Figure 2 part of the NG-RAN 235 or LMF 220 shown, or any other suitable location server such as an E-SMLC. As with other attachments provided herein, the location server 804 can be implemented as part of a network entity such as the AMF 215, or as a standalone server. Figure 1 Figure 9 are provided by way of non-limiting example. As discussed in greater detail below, alternative embodiments can perform certain functions (e.g., determining a sidelink UE position, ToA measurements, etc.) in different orders, concurrently, etc. It can be noted that, Figure 9 The arrows between the various components shown in FIG. 8 illustrate messages or information sent from one component to another. However, it should be understood that there can be any number of intermediary devices, servers, etc. that can relay these messages, including Figure 9 other components in FIG. 8 (e.g., messages from the target UE 810 to the location server 804 can be communicated through the base station 802 and possibly the sidelink UE 820, as well as other entities such as the AMF 215). Additionally, although the wireless reference signals are sometimes referred to as PRS (e.g., DL-PRS transmitted by the base station 802 and SL-PRS transmitted by the target UE 810), alternative embodiments can utilize other wireless reference signal types.

[0127] At block 905, the target UE 810 obtains a location request. The location request can be from, for example, an application (or app) executed by the target UE 810. This can be based on a scheduled determination, or based on other triggers resulting from user interaction with the target UE 810. Additionally or alternatively, the location request can be from a separate device requesting the location of the target UE 810 (e.g., the sidelink UE 820, the location server 804, or another device in communication with the target UE 810).

[0128] If the location request is not initiated by the location server 804, the target UE 810 can generate a location request notification in response to the location request at 905. As illustrated by arrow 910, a request can be sent to the location server 804, which can coordinate Figure 9 the functions of the various components shown in FIG. 8 to determine the location of the target UE 810. According to some embodiments, additional communications can be made between the target UE 810 and the location server 804 to determine capabilities of the target UE 810 (e.g., including the ability of the target UE 810 to communicate with the sidelink UE 820), whether the target UE 810 is capable or will be using differential distance and R sum_diff_j ​For example, the target UE 810 can provide an indication of whether the UE group delay is calibrated, e.g., by reporting whether it is calibrated or reporting calibration error statistics, e.g., mean and variance of the calibration error. In some implementations, the calibration status report from the target UE 810 to the location server 804 can be periodic or aperiodic, which can be triggered by an event such as UE temperature change. In some embodiments, the communication between the location server 804 and the target UE 810 can occur via an LPP positioning session.

[0129] In some embodiments, a location request notification can also be sent to the sidelink UEs 820. This can inform the sidelink UEs 820 of the location request received by the target UE 810 (at block 905) and trigger the sidelink UEs 820 to determine reference sidelink UEs at block 912 and obtain their location information at block 915. Here, the location request notification provided to the sidelink UEs 820 can also be part of a larger communication exchange in which positioning capabilities are shared between the target UE 810 and the sidelink UEs 820. According to some embodiments, the communication between the target UE 810 and the one or more sidelink UEs 820 can occur over an existing sidelink connection. Alternatively, a new sidelink connection with the one or more sidelink UEs 820 can be created in response to the location request received at block 905. According to some embodiments, the notification can be provided to the sidelink UEs 820 by the location server 804 in response to the location request notification received at stage 910, rather than the location request notification being provided by the target UE 810 to the sidelink UEs 820.

[0130] At block 912, the sidelink UEs 820 can be selected for position determination of the target UE 810 and determination of a reference sidelink UE in any of a variety of ways, depending on desired functionality. For example, as noted above, the target UE 810 can have an existing sidelink communication channel with one or more sidelink UEs 820 that can be used for positioning purposes. It will be appreciated that the location request notification sent by the target UE 810 or the location server 804 to the sidelink UEs 820 as part of stage 910 can be sent to the selected sidelink UEs 820 after selection of the sidelink UEs 820 or as part of the selection of the sidelink UEs 820. One or more sidelink UEs 820 can be selected based on the existing sidelink channel(s). Additionally or alternatively, the target UE 810 can select one or more sidelink UEs 820 based on a scan of nearby sidelink UEs and a confirmed ability and such manner to perform positioning. In some embodiments, for example, a signal quality metric such as SNR, RSSI, RSRP, or some combination thereof can be used to select the sidelink UEs 820. Additionally, the target UE 810 or the location server 804 can use the signal quality metric (after the target UE 810 reports the signal quality metric to the location server 804) to determine which sidelink UE 820 will serve as the reference sidelink UE. For example, the target UE 810 can measure the signal strength from each sidelink UE 820 and determine which sidelink UE 820 to use as the reference sidelink UE. In another example, the sidelink UEs 820 can measure the signal strength of the signals received from the target 810. The sidelink UEs 820 can send the signal strength to the location server 804, which can determine which sidelink UE 820 to use as the reference sidelink UE and, in some implementations, can send an identifier of the selected sidelink UE 820 to the target UE 810. The signal quality measurements can be used to select sidelink UEs 820 that have sufficient signal quality to perform the functionality described herein while not being too close to the target UE 810 to cause a positioning error in the position determination of the target UE 810. Thus, in such embodiments, a range of values for SNR, RSSI, RSRP, or some combination thereof can be selected to balance these considerations, and sidelink UEs whose signal quality measurements fall within the range can be selected over other sidelink UEs whose signal quality measurements fall outside the range, with the sidelink UE 820 having the best (highest) signal quality measurement being selected as the reference sidelink UE. Other embodiments can utilize additional or alternative techniques for sidelink UE selection and reference sidelink UE selection.

[0131] At block 915 and positioning session 920, the location of the sidelink UEs 820 is determined by the location server 915, for example, in a UE-assisted positioning procedure, or in some embodiments, for example, in a UE-based positioning procedure, by each respective sidelink UE 820. This can be performed in any of a variety of ways, including GNSS and / or other non-network means, and the resulting location can be reported to the location server 804. Additionally or alternatively, the location determination of the sidelink UEs 820 can be network-based and can involve the location server 804. In some cases, the sidelink UEs 820 can perform location measurements based on communications with multiple base stations, which can include communications with the base station 802, for example, for TDOA, multi-RTT, AoD, etc. positioning, which can be reported to the location server 804, and the location server 804 can determine a high-precision location determination of the sidelink UEs 820. In some cases, the sidelink UEs 820 can request assistance data, and the location server 804 can send the requested assistance data, and the sidelink UEs 820 can obtain a high-precision location determination based on location measurements based on positioning with multiple base stations, which can include communications with the base station 802, for example, for TDOA, multi-RTT, AoD, etc. positioning. For example, the assistance data can include the location of each base station with which to take positioning measurements.

[0132] At stage 925, the location server 804 sends assistance data to the target UE 810, including the location information of the sidelink UEs 820 obtained at block 915. In embodiments in which the sidelink UEs 820 obtain their own location information, the sidelink UEs 820 can send their location information directly to the target UE 810, for example, in sidelink communications or via the location server 804. The assistance data sent by the location server 804 can also include the location of the base station 802. In some embodiments, the base station 802 can send assistance data to the target UE 810 including the location of the base station 802. In some embodiments, the location server 804 can determine the distances L i between the base station 802 and each of the sidelink UEs 820 and can send the location of the sidelink UEs 820 and the distances L i instead of the location of the base station 804. The assistance data can also include timing and / or other information related to PRS to be transmitted by the base station 802.

[0133] As indicated by arrow 935, the location server can then schedule the transmission and reception of PRS resources by the base station 802, the sidelink UE 820, and the target UE 810. According to embodiments, this can include the scheduling of PRS for ToA measurements by the target UE 810 and the sidelink UE 820 (at stage 945). Alternatively, the target UE 810 and the sidelink UE 820 can schedule different PRS for measurement at different times. In some embodiments, the base station 802 can configure the sidelink UE 820 and / or the target UE 810 to measure PRS. (In this case, the scheduling of PRS resources can be considered to be sent from the base station 802 rather than the location server 804 to the sidelink UE 820 and / or the target UE 810.)

[0134] At stage 940, the base station 802 transmits PRS, which is received by the sidelink UE 820 and the target UE 810, as previously described and shown in FIG. 8 as signals 850 and 860. The sidelink UE 820 measures a ToA of the PRS, and the target UE 810 measures a ToA of the PRS. In some implementations, as indicated by the dashed lines, the base station 802 can transmit one or more PRS (e.g., using PRS resources of different beams) that are different from the PRS received by the target UE 810 for ToA measurement by the sidelink UE 820. Figure 8

[0135] At stage 945, the target UE 810 transmits PRS to the sidelink UE 820, as previously described and shown in FIG. 8 as signal 870. The PRS can include one or more signals (e.g., sidelink signals 870) transmitted via the sidelink communication channel. This can include, for example, sidelink reference signals (SL-PRS or SL-CSI-RS) or other reference signals. The target UE 810 measures a ToD of the one or more SL-PRS transmitted to each sidelink UE 820, and each sidelink UE 820 measures a ToA of the SL-PRS. Figure 8

[0136] At stage 950, the target UE 810 determines a Rx-Tx time difference between the measured ToA of the PRS received from the base station 802 at stage 940 and the measured ToD of each sidelink reference signal transmitted at stage 945 (e.g., T UE_Rx→Tx_i ), for example, as discussed in Figure 8

[0137] At stage 955, each sidelink UE 820 determines a time difference between the measured ToA of the PRS received from the base station 802 at stage 940 and the measured ToA of the SL-PRS received from the target UE 810 at stage 945 (e.g., T Rx_sidelink_i -T​​​Rx_RS_i For example, such as Figure 8 As discussed in the article.

[0138] In phase 960, each sidelink UE 820 measures the time difference (e.g., T) from phase 955. Rx_sidelink_i -T Rx_RS_i The measured time difference is sent to the target UE 810. In some embodiments, the measured time difference can be reported to the target UE 810 via sidelink communication. In some embodiments, the measured time difference can be reported to the target UE 810 via location server 804, for example, as shown by the dashed line in stage 960, by sending the time difference to location server 804. In stage 965, location server 804 sends the measured time difference to target UE 810. In the measured time difference report, each sidelink UE 820 may include the TRP ID of base station 802, the PRS ID of the PRS received in stage 940, the SL-PRS ID of the SL-PRS received in stage 945, the UE ID of target UE 810, and the UE ID of the corresponding sidelink UE 820. Each sidelink UE 820 may also include in the report the time difference (e.g., T... Rx_sidelink_i -T Rx_RS_i The associated timestamp.

[0139] In phase 970, target UE 810 can determine the differential distance and (e.g., R) of sidelink UE 820. sum_diff_j ),like Figure 8 As discussed in [the document]. For example, target UE 810 can be based on the Rx-Tx time difference (e.g., T) determined in phase 950. UE_Rx→Tx_i ) and the time difference (T) reported by each sidelink UE 820 in phase 960 (or phases 960 and 965). Rx_sidelink_i- T Rx_RS_i ), to determine the distance and (R) of each sidelink UE 820. sum_i As shown in Equation 7, the distance (R) of each sidelink UE 820 is... sum_i This can be further based on the distance L between base station 802 and each sidelink UE 820. i The target UE 810 can determine the distance L based on the location information received in phase 925. i The target UE 810 can use, for example, a reference sidelink UE determined in phase 912 to determine the differential distance and R of the sidelink UE 820. sum_diff_j .

[0140] In phase 980, target UE 810 can, based on the differential distance and R received in phase 925 by sidelink UE 820, sum_diff_jand the position of the sidelink UE 820, e.g., as discussed in Figure 8 Each differential range and sum_diff_j defines a hyperbola (or three-dimensional hyperboloid) with respect to the known positions of the reference sidelink UE and the other sidelink UE. The position of the target UE 810 can be determined as the intersection of the hyperbolas (or hyperboloids).

[0141] Figure 10 is a call flow diagram illustrating an embodiment of a UE-assisted positioning procedure that uses differential ranges determined for a plurality of sidelink UEs 820a, 820b, and 820c (sometimes collectively referred to as sidelink UEs 820 or sidelink UEs 820i, where i = a, b, and c) to determine the position of a target UE 810, as shown in Figure 8 As discussed in Figure 8 the target UE 810 can correspond to the UE 105 or 105a shown in Figure 1 and Figure 2 and in some implementations can be a light UE. The sidelink UEs 820 act as anchor UEs and can correspond to the other one of the UEs 105a or 105 shown in Figure 1 and Figure 2 and in some implementations can be an advanced UE. The base station 802 can correspond to one of the base stations 120 or access points 130 shown in Figure 1 and can be, for example, an eNB or gNB, such as the gNB 210 or ng-eNB 214 shown in Figure 2 The location server 804 can correspond to the location server 160 shown in Figure 1 and in some implementations the location server 160 can be part of the NG-RAN 235 or LMF 220 shown in Figure 2 or any other suitable location server, such as an E-SMLC. As with other Figure 1 embodiments provided herein, Figure 10 are provided by way of non-limiting example. As discussed in more detail below, alternative embodiments can perform certain functions (e.g., determining sidelink UE positions, ToA measurements, etc.) in different orders, simultaneously, etc. It can be noted that Figure 10 The arrows between the various components shown in Figure 10Other components (e.g., messages from target UE 810 to location server 804 can be transmitted via base station 802 and possibly sidelink UE 820, as well as other entities such as AMF 215). Additionally, although radio reference signals are sometimes referred to as PRS (e.g., DL-PRS transmitted by base station 802 and SL-PRS transmitted by target UE 810), alternative embodiments may utilize other radio reference signal types.

[0142] In box 1005, location server 804 receives a location request for target UE 810. This location request may, for example, come from an external client (e.g., Figure 1 External clients 180 and / or Figure 2 (External client 230). Alternatively or concurrently, the request may originate from a service within the wireless network that may require the location of the lightweight UE 410 to provide specific functionality.

[0143] In response to a location request at 1005, location server 804 may generate a location request notification. In phase 1010, location server 804 may send the location request notification to target UE 810 and (optionally) to sidelink UE 820. In some embodiments, this may include initiating a communication session between location server 804 and target UE 810, and / or between location server 804 and one or more sidelink UEs 820, to coordinate... Figure 10 The functions of the various components shown determine the location of the target UE 810. According to some embodiments, additional communication may be performed between the target UE 810 and the location server 804 to determine the capabilities of the target UE 810 (e.g., the ability of the target UE 810 to communicate with the sidelink UE 820), whether the target UE 810 is capable of or will use differential distance and R... sum_diff_j For example, the target UE 810 can provide an indication of whether the UE group latency has been calibrated, for example by reporting whether it has been calibrated or by reporting calibration error statistics, such as the mean and variance of the calibration error. In some implementations, the calibration status report from the target UE 810 to the location server 804 can be periodic or aperiodic, which can be triggered by events such as changes in UE temperature. In some embodiments, communication between the location server 804 and the target UE 810 can occur via an LPP positioning session.

[0144] The location request notification can be sent to the sidelink UEs 820 to inform the sidelink UEs 820 of the location request received by the target UE 810 (at block 1010). The sidelink UEs 820 can be triggered by the location request notification to determine the reference sidelink UEs at block 1012 and obtain their location information at block 1015. According to some embodiments, the notification can be provided by the target UE 810 to the sidelink UEs 820 in response to receiving the location request notification at stage 1010, instead of the location request notification being provided by the location server 804 to the sidelink UEs 820. According to some embodiments, the communication between the target UE 810 and the one or more sidelink UEs 820 can occur over an existing sidelink connection. Alternatively, a new sidelink connection with the one or more sidelink UEs 820 can be created in response to the location request received at block 1010.

[0145] As previously described, elements 1012-1055 can be similar to corresponding features 912-955 in FIG. 9. Figure 9 If the determination of the differential range sum is made at the location server 804 instead of at the target UE 810, the locations of the sidelink UEs 820 and the base station 802 or the distance L i does not need to be sent to the target UE 810 in the assistance data. Further, if the determination of the differential range sum is made at the location server 804 instead of at the target UE 810, the selection of the reference sidelink UEs can be made by the location server 804 and needs to be communicated to the target UE 810. Otherwise, the assistance data can be sent to the target UE 810 in stage 1025.

[0146] At stage 1060, each sidelink UE 820 sends its measured time difference (e.g., T Rx_sidelink_i -T Rx_RS_i ) from stage 1055 to the location server 804. In some implementations, e.g., where the target UE 810 determines the differential range sum, the sidelink UEs 820 can send their measured time differences to the target UE 81, e.g., via sidelink communication, as indicated by the dashed lines in stage 1060. In the measured time difference report, each sidelink UE 820 can include the TRP ID of the base station 802, the PRS ID of the PRS received at stage 1040, the SL-PRS ID of the SL-PRS received at stage 1045, the UE ID of the target UE 810, and the UE ID of the respective sidelink UE 820. Each sidelink UE 820 can also include a timestamp associated with the measured time difference (e.g., T Rx_sidelink_i -T Rx_RS_i ) in the report.

[0147] In phase 1065, target UE 810 processes the Rx-Tx time difference (e.g., Tx) measured in phase 1050. UE_Rx→Tx_i To generate differential distances, for example, by preparing a report with measured Rx-Tx differences and sending it to location server 804. For each reported Rx-Tx time difference (T... UE_Rx→Tx_i The target UE 810 may include the TRP ID of base station 802, the PRS ID of the PRS received in phase 1040, the SL-PRS ID of the corresponding SL-PRS transmitted in phase 1045, the UE ID of the target UE 810, and the UE ID of the sidelink UE 820 that received the corresponding sidelink reference signal. The target UE 810 may also include in the report the time difference (T) for each Rx-Tx. UE_Rx→Tx_i The associated timestamp.

[0148] In phase 1070, location server 804 can determine the differential distance of sidelink UE 820 and (e.g., R... sum_diff_j ),like Figure 8 As discussed in [the document]. For example, location server 804 can base its location on the Rx-Tx time difference (e.g., Tx) reported by target UE 810 in phase 1065. UE_Rx→Tx_i ) and the time difference (T) reported by each sidelink UE 820 in phase 1060. Rx_sidelink_i- T Rx_RS_i ), to determine the distance and (R) of each sidelink UE 820. sum_i As shown in Equation 7, the distance (R) of each sidelink UE 820 is... sum_i This can be further based on the distance L between base station 802 and each sidelink UE 820. i The location server 804 can determine the distance L based on the location received from the sidelink UE 820 in phase 1015. i Location server 804 can use, for example, the reference sidelink UE determined in phase 1012 to determine the differential distance and R of sidelink UE 820. sum_diff_j .

[0149] In optional phase 1075, target UE 810 processes the Rx-Tx time difference (e.g., Tx) measured in phase 1050. UE_Rx→Tx_i To generate the differential distance sum, for example, by using the Rx-Tx time difference sum in phase 1060 (similar to...). Figure 9 In stage 970, the time difference (T) reported by each sidelink UE 820 to the target UE 810 instead of the location server 804 is... Rx_sidelink_i- T Rx_RS_i To determine the difference distance.

[0150] At optional stage 1078, if the target UE 810 determines a differential range sum at stage 1075, the target UE 810 reports the differential range sum to the location server 804. For each differential range sum reported to the location server 804, the target UE 810 can include the TRP ID of the base station 802, the PRS ID of the PRS received at stage 1040, the SL-PRS ID of the corresponding SL-PRS transmitted at stage 1045, the UE ID of the target UE 810, and the UE IDs of the reference sidelink UE 820 and the other sidelink UE 820 at which the corresponding sidelink reference signals were received at stage 1045. The target UE 810 can also include a timestamp associated with each differential range sum in the report.

[0151] At stage 1080, the location server 804 can determine the location of the target UE 810 based on the differential range sums Rsum_diff_j received at stage 1015 for the sidelink UEs 820 and the locations of the sidelink UEs 820, e.g., as discussed in sum_diff_j Figure 8 For example, each differential range sum sum_diff_j defines a hyperbola (or a three-dimensional hyperboloid) with respect to the known locations of the reference sidelink UE and the other sidelink UE. The location of the target UE 810 can be determined as the intersection of the hyperbolas (or hyperboloids).

[0152] Figure 11 A block diagram illustrating certain example features of a UE 1100, e.g., a target UE, a sidelink UE, or other UE described herein, configured to support positioning using differential range sums, e.g., as discussed herein, is shown. For example, the UE 1100 can perform the signal flows shown in Figure 9 and Figure 10 and the processing flows shown in Figure 13 and Figure 16 and the algorithms disclosed herein. For example, the UE 1100 can include one or more processors 1102, memory 1104, external interfaces (e.g., wireless network interfaces) such as at least one wireless transceiver (shown as WWAN transceiver 1110 and WLAN transceiver 1112), an SPS receiver 1115, and one or more sensors 1113, which can be operatively coupled to non-transitory computer-readable media 1120 and memory 1104 with one or more connections 1106 (e.g., buses, lines, fibers, links, etc.). For example, the SPS receiver 1115 can receive SPS signals from one or more SPS satellites 1122, e.g., as discussed herein. The UE 1100 can also include one or more user interfaces 1108, such as a microphone, a camera, a speaker, a keypad, a display, etc. For example, the UE 1100 can include a display and one or more buttons, e.g., as discussed herein. Figure 1 ​The illustrated SV 190 receives and processes SPS signals. The one or more sensors 1113 can be, for example, an inertial measurement unit (IMU), which can include one or more accelerometers, one or more gyroscopes, a magnetometer, and the like. The UE 1100 can also include additional items not shown, such as a user interface that can include, for example, a display, a keyboard or other input device, such as a virtual keyboard on a display through which a user can interact with the UE. In certain example implementations, all or a portion of the UE 1100 can take the form of a chip set or the like.

[0153] The UE 1100 can include at least one wireless transceiver, such as a transceiver 1110 for WWAN communication systems and a transceiver 1112 for WLAN communication systems, or a combination transceiver for WWAN and WLAN. The WWAN transceiver 1110 can include a transmitter 1110t and a receiver 1110r coupled to one or more antennas 1111 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 and converting the signals from wireless signals to wired (e.g., electrical and / or optical) signals and from wired (e.g., electrical and / or optical) signals to wireless signals. The WLAN transceiver 1112 can include a transmitter 1112t and a receiver 1112r coupled to one or more antennas 1111 or to separate antennas 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 and converting the signals from wireless signals to wired (e.g., electrical and / or optical) signals and from wired (e.g., electrical and / or optical) signals to wireless signals. The transmitters 1110t and 1112t can include multiple transmitters that can be discrete components or combined / integrated components, and / or the receivers 1110r and 1112r can include multiple receivers that can be discrete components or combined / integrated components. The WWAN transceiver 1110 can be configured to communicate signals (e.g., with base stations and / or one or more other devices) according to various radio access technologies (RATs) such as 11G New Radio (NR), GSM (Global System for Mobiles), UMTS (Universal Mobile Telecommunication System), AMPS (Advanced Mobile Phone System), CDMA (Code-Division Multiple Access), WCDMA (Widezone CDMA), LTE (Long-Term Evolution), LTE Direct (LTE-D), 3GPP LTE-V2X (PC5), etc. New Radio can use millimeter wave frequencies and / or sub-6 GHz frequencies. The WLAN transceiver 1112 can be configured to communicate signals (e.g., with access points and / or one or more other devices) according to various radio access technologies (RATs) such as 3GPP LTE-V2X (PC5), IEEE 802.11 (including IEEE 802.11p), WiFi, WiFi Direct (WiFi-D), Zigbee, etc. The transceivers 1110 and 1112 may, for example, be communicatively coupled to a transceiver interface through optical and / or electrical connections, which can be at least partially integrated with the transceivers 1110 and 1112. Zigbee, etc. The transceivers 1110 and 1112 may, for example, be communicatively coupled to a transceiver interface through optical and / or electrical connections, which can be at least partially integrated with the transceivers 1110 and 1112.

[0154] In some embodiments, the UE 1100 can include an antenna 1111, which can be internal or external. The UE antenna 1111 can be used to transmit and / or receive signals processed by the wireless transceivers 1110 and 1112. In some embodiments, the UE antenna 1111 can be coupled to the wireless transceivers 1110 and 1112. In some embodiments, measurements can be performed on signals received (transmitted) by the UE 1100 at the point of connection of the UE antenna 1111 to the wireless transceivers 1110 and 1112. For example, the measurement reference point for receiving (transmitting) RF signal measurements can be the input (output) terminal of the receiver 1110r (transmitter 1110t) and the output (input) terminal of the UE antenna 1111. In a UE 1100 with multiple UE antennas 1111 or antenna arrays, the antenna connectors can be considered as a virtual point representing the aggregated output (input) of the multiple UE antennas. In some embodiments, the UE 1100 can measure received signals, including signal strength and TOA measurements, and the raw measurements can be processed by the one or more processors 1102.

[0155] The one or more processors 1102 can be implemented using a combination of hardware, firmware, and software. For example, the one or more processors 1102 can be configured to perform the functions discussed herein by implementing one or more instructions or program code 1108 on a non-transitory computer readable medium such as the medium 1120 and / or the memory 1104. In some embodiments, the one or more processors 1102 can represent one or more circuits configurable to perform at least a portion of a data signal computational process or procedure related to the operation of the UE 1100.

[0156] The medium 1120 and / or the memory 1104 can store instructions or program code 1108 containing executable code or software instructions that, when executed by the one or more processors 1102, cause the one or more processors 1102 to operate as a special purpose computer programmed to perform the techniques disclosed herein. As shown in the UE 1100, the medium 1120 and / or the memory 1104 can include one or more components or modules that can be executed by the one or more processors 1102 to perform the methods described herein. While the components or modules are shown as software in the medium 1120 that is executed by the one or more processors 1102, it should be understood that the components or modules can be stored in the memory 1104 or can be special purpose hardware within the one or more processors 1102 or external to the processors.

[0157] A number of software modules and data tables can reside in media 1120 and / or memory 1104 and be used by one or more processors 1102 to manage communication and the functions described herein. It should be appreciated that the organization of the content of media 1120 and / or memory 1104 as shown in UE 1100 is merely exemplary and, therefore, the functionality of the modules and / or data structures can be combined, separated, and / or be distributed in a different manner depending on the implementation of UE 1100.

[0158] Media 1120 and / or memory 1104 can include a reference signal reception module 1122 that, when implemented by one or more processors 1102, configures the one or more processors 1102 to receive a reference signal (e.g., a DL PRS for positioning, a SL PRS, a CSI-RS, etc.) from an access point, a base station, or another UE and measure a time of arrival (ToA) of the reference signal, e.g., via wireless transceiver 1110.

[0159] Media 1120 and / or memory 1104 can include a sidelink reference signal module 1124 that, when implemented by one or more processors 1102, configures the one or more processors 1102 to transmit one or more sidelink reference signals (e.g., a SL PRS for positioning, a SL CSI-RS, etc.) to a plurality of sidelink UEs and measure a time of departure (ToD) of the reference signal transmission, e.g., via wireless transceiver 1110.

[0160] Media 1120 and / or memory 1104 can include a time difference module 1126 that, when implemented by one or more processors 1102, configures the one or more processors 1102 to determine a Rx-Tx time difference (T UE_Rx→Tx_i ) between a reception (e.g., a measured ToA) of a reference signal received from a network entity and a transmission (e.g., a measured ToD) of a sidelink reference signal transmitted to each of a plurality of sidelink UEs. Rx_sidelink_i -T Rx_RS_i ) between a reception (e.g., a ToA) of a reference signal from a network entity and a reception (e.g., a ToA) of a sidelink reference signal received from another UE.

[0161] Media 1120 and / or memory 1104 can include a reporting module 1128 that, when implemented by one or more processors 1102, configures the one or more processors 1102 to receive or transmit, e.g., via wireless transceiver 1110, a report including one or more measured parameters (e.g., a Rx-Tx time difference (T UE_Rx→Tx_i ), a time difference (TRx_sidelink_i -T Rx_RS_i The report includes, for example, a determined distance sum, a differential distance sum, etc. One or more processors 1102 may also be configured to include in the report an identifier of the network entity from which reference signals are received, an identifier of the reference signals received from the network entity, an identifier of the transmitted or received SL reference signals, an identifier of the UE, and an identifier of each sidelink UE, as well as a timestamp associated with the measured parameters. One or more processors 1102 may also be configured to transmit, for example, the group delay state of the UE via radio transceiver 1110, which may be transmitted periodically, non-periodically, event-triggered, or a combination thereof.

[0162] The medium 1120 and / or memory 1104 may include a distance summing module 1130, which, when implemented by one or more processors 1102, configures the one or more processors 1102 to determine a distance sum for each sidelink UE, the distance sum being the sum of a first distance between the UE and a network entity and a second distance between the UE and each corresponding sidelink UE. The one or more processors 1102 may be configured to base their distance sum on the Rx-Tx time difference (T...). UE_Rx→Tx_i ), time difference (T) Rx_sidelink_i -T Rx_RS_i The distance and (R) are determined by the distance between the UE and the network entity on the side link. sum_i For example, see reference. Figure 8 As described.

[0163] The medium 1120 and / or memory 1104 may include a differential distance sum module 1132, which, when implemented by one or more processors 1102, configures the one or more processors 1102 to determine the differential distance sums of multiple side-link UEs. For example, one or more processors 1102 may be configured to calculate the differential distance sums R... sum_diff_j The sum of distances (R) from multiple sidelink UEs to the reference sidelink UE is determined. sum_Ref The distance to each other sidelink UE and (R) sum_j The difference between, for example, as in the reference Figure 8 As described.

[0164] The medium 1120 and / or the memory 1104 can include a reference SL UE module 1134 that, when implemented by the one or more processors 1102, configures the one or more processors 1102 to receive an identifier of a reference sidelink UE from a location server, or to determine a reference sidelink UE, e.g., via the wireless transceiver 1110. For example, the one or more processors 1102 can be configured to determine a signal strength of a sidelink signal received from one or more other UEs, e.g., RSSI, RSRP, SNR, etc., via the wireless transceiver 1110. For example, the one or more processors 1102 can be configured to determine a signal strength of a sidelink signal received from each sidelink UE. In another example, the one or more processors 1102 can be configured to determine a signal strength of a sidelink signal received from a target UE, and report the signal strength to the location server or the target UE. The one or more processors 1102 can be configured to select a reference sidelink UE based at least in part on a highest signal strength. Other parameters that can be used can relate to the sidelink connection, e.g., persistence of the sidelink connection, or geometry of the sidelink UE locations, geometric dilution of precision (GDOP), etc.

[0165] The medium 1120 and / or the memory 1104 can include a group delay state module 1136 that, when implemented by the one or more processors 1102, configures the one or more processors 1102 to determine a group delay state of the wireless transceiver 1110 and / or the wireless transceiver 1112. The group delay state can be an indication of whether the group delay is calibrated. The group delay state can be a calibration error statistic of the group delay, e.g., a mean and a variance of the calibration error. The one or more processors 1102 can be configured to report the group delay state to a location server via the wireless transceiver 1110. The group delay state can be reported periodically, aperiodically, triggered by an event, or a combination thereof, for example.

[0166] The medium 1120 and / or the memory 1104 can include a positioning module 1138 that, when implemented by the one or more processors 1102, configures the one or more processors 1102 to determine a location of the UE 1100 based at least in part on differential range sums of the plurality of sidelink UEs. The location of the UE 1100 can be determined further based on locations of the sidelink UEs, e.g., received in assistance data, for example. The location of the UE can be determined based on an intersection of a hyperbola or hyperboloid resulting from the differential range sums with the locations of the sidelink UEs, e.g., as discussed in Figure 8

[0167] ​The medium 1120 and / or the memory 1104 can include a assistance data module 1140 that, when implemented by the one or more processors 1102, configures the one or more processors 1102 to receive assistance data from any of a location server, a base station, or a sidelink UE via the wireless transceiver 1110, which can include a location of the sidelink UE and a location of the base station.

[0168] The methods described herein can be implemented in a number of ways. For example, these methods can be implemented in hardware, firmware, software, or any combination thereof. For a hardware implementation, the one or more processors 1102 can be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof.

[0169] For firmware and / or software, the methods can be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. Any machine readable medium tangibly embodying instructions can be used in implementation of the methods described herein. For example, software codes can be stored in the non-transitory computer-readable medium 1120 or the memory 1104 that is connected to and executed by the one or more processors 1102. The memory can be implemented within the one or more processors or external to the one or more processors. As used herein, the term “memory” refers to any type of long-term, short-term, volatile, nonvolatile, or other memory and is not limited to any particular type of memory or number of memories, or type of media upon which memory is stored.

[0170] If implemented in firmware and / or software, the functions can be stored as one or more instructions or program code 1108 on a non-transitory computer readable medium such as the medium 1120 and / or the memory 1104. Examples include computer readable media encoded with a data structure encoded with a computer program 1108. For example, the non-transitory computer readable medium including program code 1108 stored thereon can include program code 1108 to support positioning of a UE by storing UE positioning capabilities in a core network in a manner consistent with the disclosed embodiments. The non-transitory computer readable medium 1120 includes physical computer storage media. A storage medium can be any available medium or means of storing data accessible by a computer. By way of example, and not limitation, such computer readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store desired program code 1108 in the form of instructions or data structures and which can be accessed by a computer; disk and disc, as used herein, includes compact discs (CD), laser discs, optical discs, digital versatile discs (DVD), floppy disks and blu-ray discs where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer readable media.

[0171] In addition to storage on computer readable medium 1120, instructions and / or data can be provided as signals on transmission media included in a communication apparatus. For example, a communication apparatus can include a wireless transceiver 1110 having signals indicative of instructions and data. The instructions and data are configured to cause one or more processors to implement the functions outlined in the claims. That is, the communication apparatus includes transmission media with signals indicative of information to perform disclosed functions.

[0172] Memory 1104 can be representative of any data storage mechanism. Memory 1104 can include, for example, a main memory and / or a secondary memory. Main memory can include, for example, a random access memory, read only memory, etc. While shown as being separate from the processor(s) 1102 in this example, it is to be understood that all or a portion of a main memory can be provided within the processor(s) 1102, or as otherwise co-located / coupled with the processor(s) 1102 in a manner consistent with the claims. Secondary memory can include, for example, the same or similar type of memory as the main memory and / or one or more data storage devices or systems external to the processor(s) 1102, such as a disk drive, optical disk drive, tape drive, solid state storage drive, etc.

[0173] In some embodiments, an auxiliary storage device is operatively configured to receive, or otherwise coupled to, the non-transitory computer-readable medium 1120. Therefore, in some example embodiments, the methods and / or apparatus presented herein may take the form of all or part of a computer-readable medium 1120, which may include computer-implementable code 1108 stored thereon, which, if executed by one or more processors 1102, is operatively capable of performing all or part of the example operations as described herein. The computer-readable medium 1120 may be part of a memory 1104.

[0174] Figure 12 The image shows location server 1200 (e.g., Figure 1 The schematic block diagram shown illustrates certain exemplary features of the LMF 152 or SLP 162, wherein the location server 1200 is configured to support the use of differential distance and positioning of the UE, for example, as discussed herein. The location server 1200 can perform... Figure 9 and Figure 10 The signaling flow shown and, for example Figure 14 and Figure 15 The processing flow shown herein and the algorithms disclosed herein. Location server 1200 may include, for example, one or more processors 1202, memory 1204, and external interfaces 1216 (e.g., wired or wireless network interfaces to base stations and / or entities in the core network), which may be operatively coupled to non-transitory computer-readable medium 1220 and memory 1204 via one or more connections 1206 (e.g., bus, line, fiber, link, etc.). In some example embodiments, all or part of location server 1200 may take the form of a chipset, etc.

[0175] One or more processors 1202 may be implemented using a combination of hardware, firmware, and software. For example, one or more processors 1202 may be configured to perform the functions discussed herein by implementing one or more instructions or program code 1208 on a non-transitory computer-readable medium such as medium 1220 and / or memory 1204. In some embodiments, one or more processors 1202 may represent one or more circuits configured to perform at least a portion of a data signal calculation process or process in relation to the operation of location server 1200.

[0176] The medium 1220 and / or the memory 1204 can store instructions or program code 1208 that contain executable code or software instructions that, when executed by the one or more processors 1202, cause the one or more processors 1202 to operate as a special purpose computer programmed to perform the techniques disclosed herein. As shown in the location server 1200, the medium 1220 and / or the memory 1204 can include one or more components or modules that can be executed by the one or more processors 1202 to perform the methods described herein. While the components or modules are shown as software in the medium 1220 that is executed by the one or more processors 1202, it should be understood that the components or modules can be stored in the memory 1204 or can be special-purpose hardware within or outside of the one or more processors 1202.

[0177] A number of software modules and data tables can reside in the medium 1220 and / or the memory 1204 and be used by the one or more processors 1202 to manage communications and the functions described herein. It should be appreciated that the organization of the contents of the medium 1220 and / or the memory 1204 as shown in the location server 1200 is merely exemplary and, therefore, the functions of the modules and / or data structures can be combined, separated, and / or be structured in different ways depending on the implementation of the location server 1200.

[0178] The medium 1220 and / or the memory 1204 can include a reporting module 1222 that, when executed by the one or more processors 1202, configures the one or more processors 1202 to receive reports from the sidelink UEs and the target UE, e.g., via the external interface 1210, that include one or more measured parameters, such as a Rx-Tx time difference (T UE_Rx→Tx_i ), a time difference (T Rx_sidelink_i -T Rx_RS_i ) from the sidelink UEs, a determined range and a range difference from the target UE, etc. The one or more processors 1202 can also be configured to receive in the reports an identifier of a network entity from which the reference signals were received, an identifier of the reference signals received from the network entity, an identifier of the SL reference signals transmitted or received, an identifier of the UE and each sidelink UE, and a timestamp associated with the measured parameters. The one or more processors 1202 can be configured to transmit or forward the reports, e.g., the time difference (T Rx_sidelink_i -T Rx_RS_iThis includes, for example, any received identifiers and timestamps. One or more processors 1202 may also be configured to receive, for example, the group delay state of the UE via an external interface 1210, which may be sent periodically, aperiodically, by event triggering, or a combination thereof.

[0179] The medium 1220 and / or memory 1204 may include a distance summing module 1224, which, when implemented by one or more processors 1202, configures the one or more processors 1202 to determine a distance sum for each sidelink UE, the distance sum being the sum of a first distance between the UE and a network entity and a second distance between the UE and each corresponding sidelink UE. The one or more processors 1202 may be configured to base their distance sum on the Rx-Tx time difference (T...). UE_Rx→Tx_i ), time difference (T) Rx_sidelink_i -T Rx_RS_i The distance and (R) are determined by the distance between the UE and the network entity on the side link. sum_i For example, see reference. Figure 8 As described.

[0180] The medium 1220 and / or memory 1204 may include a differential distance sum module 1226, which, when implemented by one or more processors 1202, configures the one or more processors 1202 to determine the differential distance sums of multiple sidelink UEs. For example, one or more processors 1202 may be configured to calculate the differential distance sums. sum_diff_j The sum of distances (R) from multiple sidelink UEs to the reference sidelink UE is determined. sum_Ref The distance to each other sidelink UE and (R) sum_j The difference between, for example, as in the reference Figure 8 As described.

[0181] The medium 1220 and / or memory 1204 may include a positioning module 1228, which, when implemented by one or more processors 1202, configures the one or more processors 1202 to determine the location of a target UE based at least in part on the differential distance sum of a plurality of side-link UEs. For example, the location of the UE may be further determined based on the location of the side-link UEs. For example, the location of the UE may be determined based on the intersection of a hyperbola or hyperboloid generated by the differential distance sum with the location of the side-link UE, such as... Figure 8 As discussed in the article.

[0182] The medium 1220 and / or the memory 1204 can include a reference SL UE module 1230 that, when implemented by the one or more processors 1202, configures the one or more processors 1202 to receive information for determining a reference sidelink UE and determine the reference sidelink UE via the external interface 1210. For example, the one or more processors 1202 can be configured to receive, via the external interface 1210, an identifier of the reference sidelink UE, e.g., from the target UE, or a signal strength measurement of a sidelink signal from the target UE and / or sidelink UE, e.g., RSSI, RSRP, SNR, etc. The one or more processors 1202 can be configured to select the reference sidelink UE based at least in part on a highest signal strength. Other parameters that can be used can relate to the sidelink connection, e.g., persistence of the sidelink connection, or geometry of the sidelink UE locations, geometric dilution of precision (GDOP), etc. The one or more processors 1202 can be configured to transmit, via the external interface 1210, the identifier of the reference sidelink UE to the target UE.

[0183] The medium 1220 and / or the memory 1204 can include a group delay state module 1232 that, when implemented by the one or more processors 1202, configures the one or more processors 1202 to receive a group delay state from a UE via the external interface 1210. The group delay state can be an indication of whether a group delay is calibrated. The group delay state can be a calibration error statistic of the group delay, e.g., a mean and a variance of the calibration error. The group delay state can be received periodically, aperiodically, triggered by an event, or a combination thereof, for example.

[0184] The medium 1220 and / or the memory 1204 can include an assistance data module 1234 that, when implemented by the one or more processors 1202, configures the one or more processors 1202 to prepare and transmit, via the external interface 1210, assistance data to the target UE, which can include a location of the sidelink UE and a location of the base station.

[0185] The methods described herein can be implemented in a variety of ways. For example, these methods can be implemented in hardware, firmware, software, or any combination thereof. For a hardware implementation, the one or more processors 1202 can be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof.

[0186] For firmware and / or software-based implementations, the methods can be implemented with modules (e.g., procedures, functions, and so on) that perform the functions described herein. Any machine readable medium tangibly embodying instructions can be used in implementing the methods described herein. For example, software codes can be stored in a non-transitory computer-readable medium 1220 or memory 1204 that is connected to or otherwise accessible by one or more processors 1202 and executed thereon. The memory can be implemented within the one or more processors or external to the one or more processors. As used herein, the term “memory” refers to any type of long-term, short-term, volatile, nonvolatile, or other memory and is not limited to any particular type of memory or number of memories, or type of media upon which memory is stored.

[0187] If implemented in firmware and / or software, the functions can be stored as one or more instructions or program code 1208 on a non-transitory computer-readable medium, such as medium 1220 and / or memory 1204. Examples include computer readable media encoded with a data structure and computer readable media encoded with a computer program 1208. For example, a non-transitory computer-readable medium including program code 1208 stored thereon can include program code 1208 to support location determination of a target UE using differential ranges in a manner consistent with the disclosed embodiments. Non-transitory computer readable medium 1220 includes physical computer storage media. A storage medium can be any available medium that can be accessed by a computer. By way of example, and not limitation, such non-transitory computer readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code 1208 in the form of instructions or data structures and that can be accessed by a computer; disk and

[0188] In addition to storage on computer readable medium 1220, instructions and / or data can be provided as signals on transmission media included in a communication apparatus. For example, a communication apparatus can include a network adapter 1216 to provide electrical, electromagnetic, or optical signals that carry information acoustically, optically, or via a physical connection. The instructions and / or data are configured to cause one or more processors to implement the functions outlined in the claims. That is, the communication apparatus includes transmission media with signals indicative of information to implement the functions

[0189] Memory 1204 can represent any data storage mechanism. Memory 1204 can include, for example, a main memory and / or a static memory. Main memory can include, for example, a random access memory, read-only memory, etc. While shown as being separate from the processor(s) 1202 in this example, it is to be understood that all or a portion of the main memory can be provided within the processor(s) 1202, or as part of the processor(s) 1202 in, for example, a processor-on-a-chip platform. Static memory can include, for example, a magnetic disk, optical disk, tape, etc.

[0190] In certain embodiments, the secondary memory is operatively receptive of the non-transitory computer readable medium 1220, or is otherwise configurable to couple to the non-transitory computer readable medium 1220. Thus, in certain example embodiments, the methods and / or apparatuses presented herein can employ, in whole or in part, a computer readable medium 1220 that can include computer executable code 1208 stored thereon that, if executed by the processor(s) 1202, operatively enables the performance of all or a portion of the example operations described herein. The computer readable medium 1220 can be a portion of the memory 1204.

[0191] Figure 13 A flow diagram of an example method 1300 for determining a location of a first UE in a wireless network is shown, the method being performed by the first UE in a manner consistent with the disclosed embodiments. The first UE can be a target UE or a light UE, such as the UE 105 shown in Figure 1 and Figure 2 the target UE 810 shown in Figure 8 , Figure 9 and Figure 10 the UE 1100 shown in Figure 11 operating as a target UE.

[0192] At block 1302, the first UE receives a first reference signal from a network entity, e.g., as discussed in stage 940 in Figure 9 and stage 1040 in Figure 10 . For example, the reference signal can be a DL PRS signal for positioning or other DL reference signal, e.g., the reference signal 850 shown in Figure 8 , and the network entity can be a base station, e.g., an eNB or gNB, or an access point, and is shown as Figure 8 , Figure 9 and Figure 10The base station 802 shown. Components for receiving the first reference signal from the network entity may include, for example, a wireless transceiver 1110 or wireless transceiver 1112 and one or more processors 1102, the one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in memory 1104 and / or media 1120 in the UE 1100, for example... Figure 11 The reference signal receiving module 1122 shown is shown.

[0193] In box 1304, the first UE sends one or more sidelink reference signals to multiple sidelink UEs, for example, such as Figure 9 Phase 945 and Figure 10 This is discussed in stage 1045. For example, the side link reference signal could be an SL-PRS or SL-CSI-RS used for positioning, for example. Figure 8 The reference signal 860 is shown. Components for transmitting one or more sidelink reference signals to multiple sidelink UEs may include, for example, a wireless transceiver 1110 or wireless transceiver 1112 and one or more processors 1102, the one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in the memory 1104 and / or medium 1120 of the UE 1100, for example... Figure 11 The side link reference signal module 1124 is shown.

[0194] In box 1306, the first UE determines the receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is the time difference between receiving the first reference signal from the network entity and transmitting the sidelink reference signal to the corresponding sidelink UE, for example, as Figure 9 Phase 950 and Figure 10 The discussion in stage 1050. For example, the Rx-Tx time difference for each sidelink UE can be determined as the Rx-Tx time difference (T) between the reception of reference signal 850 (e.g., measured ToA) and the transmission (e.g., measured ToD) of sidelink reference signal 870i sent to the corresponding sidelink UE 820i. UE_Rx→Tx_i For example, such as Figure 8 As described in [the document]. A component for determining the receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is the time difference between receiving a first reference signal from the network entity and transmitting a sidelink reference signal to the corresponding sidelink UE, may include, for example, one or more processors 1102, which have dedicated hardware or implement executable code or software instructions in the memory 1104 and / or medium 1120 of the UE 1100, such as [example code]. Figure 11The time difference module 1126 shown is illustrated.

[0195] In block 1308, the first UE processes the Rx-Tx time difference associated with each sidelink UE to generate a differential distance sum of multiple sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE, wherein the time difference measured by each sidelink UE is the time difference between the first UE receiving a sidelink reference signal and receiving a second reference signal from the network entity, each differential distance sum is the difference between the distance sum of a reference sidelink UE from the multiple sidelink UEs and the distance sum of another sidelink UE from the multiple sidelink UEs, and wherein the distance sum of each sidelink UE is the sum of a first distance between the first UE and the network entity and a second distance between the first UE and the corresponding sidelink UE, wherein the location of the first UE is determined at least in part based on the differential distance sum of the multiple sidelink UEs, for example, as in Figure 9 Phases 970 and 980 and Figure 10 The stages discussed in 1065, 1075, 1078, and 1080. In one example, a first UE may participate in UE-based localization, where the first UE processes the Rx-Tx time difference associated with each sidelink UE to generate a differential distance sum by determining the differential distance sum, as... Figure 8 The discussion in and in Figure 9 This is discussed in stage 970. In one example, the first UE can participate in UE-assisted localization, where the first UE processes the Rx-Tx time difference associated with each sidelink UE to generate a differential distance sum by preparing a report and sending the Rx-Tx time difference associated with each sidelink UE to the location server to generate a differential distance sum, as shown in the example. Figure 8 The discussion in and in Figure 10 As discussed in stage 1065, or by determining the differential distance and sending the differential distance to the location server to determine the UE's location, such as... Figure 8 The discussion in and in Figure 10 The phases 1075 and 1078 are discussed. For example, the time difference measured by each sidelink UE is the time difference (T) between the reception (e.g., ToA) of the reference signal 860 transmitted by the base station 802 and the reception (e.g., ToA) of the sidelink reference signal 870i transmitted by the first UE 810, as measured by each sidelink UE 820i. Rx_sidelink_i -T Rx_RS_i For example, such as Figure 8The means for processing the Rx-Tx time difference associated with each sidelink UE to generate differential range sums for the plurality of sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and a time difference measured by each sidelink UE, where the time difference measured by each sidelink UE is a time difference between receiving a sidelink reference signal from the first UE and receiving a second reference signal from the network entity, each differential range sum is a difference between a range sum from a reference sidelink UE of the plurality of sidelink UEs and a range sum from another sidelink UE of the plurality of sidelink UEs, and where the range sum for each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE, where the location of the first UE is determined based at least in part on the differential range sums for the plurality of sidelink UEs, can include, for example, the wireless transceiver 1110 or the wireless transceiver 1112 and the one or more processors 1102 with dedicated hardware or implementing executable code or software instructions in the memory 1104 and / or the medium 1120 of the UE 1100, for example Figure 11 the reporting module 1128 and / or the range sum module 1130 and the differential range sum module 1132 as shown.

[0196] In one implementation, the first UE can also receive a time difference measured by each sidelink UE of the plurality of sidelink UEs, for example, as discussed in stages 960 and 965 of FIG. 9 and stages 1060 of FIG. 10. Figure 9 In one implementation, the first UE can also receive a time difference measured by each sidelink UE of the plurality of sidelink UEs, for example, as discussed in stages 960 and 965 of FIG. 9 and stages 1060 of FIG. 10. Figure 10 The means for receiving the time difference measured by each sidelink UE of the plurality of sidelink UEs can include, for example, the wireless transceiver 1110 or the wireless transceiver 1112 and the one or more processors 1102 with dedicated hardware or implementing executable code or software instructions in the memory 1104 and / or the medium 1120 of the UE 1100, for example Figure 11 The reporting module 1128 as shown. For example, processing the Rx-Tx time difference associated with each sidelink UE to generate differential range sums for the plurality of sidelink UEs can include determining the differential range sums for the plurality of sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and a time difference measured by each sidelink UE, for example, as discussed in stage 970 of FIG. 9 or stage 1070 of FIG. 10. Figure 9 The reporting module 1128 as shown. For example, processing the Rx-Tx time difference associated with each sidelink UE to generate differential range sums for the plurality of sidelink UEs can include determining the differential range sums for the plurality of sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and a time difference measured by each sidelink UE, for example, as discussed in stage 970 of FIG. 9 or stage 1070 of FIG. 10. Figure 10The components discussed in stage 1075, used to determine the differential distance sum of multiple sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE, may include, for example, one or more processors 1102, which have dedicated hardware or implement executable code or software instructions in the memory 1104 and / or medium 1120 of the UE 1100, such as... Figure 11 The distance and differential distance modules 1130 and 1132 are shown.

[0197] For example, the first UE can determine the differential distance sum by determining the distance sum for each sidelink UE based on the Rx-Tx time difference associated with the corresponding sidelink UE and the time difference measured by the corresponding sidelink UE, for example, as... Figure 9 Stage 970 or Figure 10 The phase 1075 discussed. For example, the first UE can determine the distance (R) of each of the multiple side-link UEs 820. sum As discussed in Phase 8, the components for determining the distance sum for each sidelink UE based on the Rx-Tx time difference associated with the corresponding sidelink UE and the time difference measured by the corresponding sidelink UE may include, for example, one or more processors 1102, which have dedicated hardware or implement executable code or software instructions in memory 1104 and / or media 1120 in UE 1100, such as... Figure 11 The distance and module 1130 are shown. The first UE can also determine the difference between the distance and the distance and the sum of distances from the reference sidelink UE and the distance and the sum of distances from each of the multiple sidelink UEs, for example, as in Figure 9 Stage 970 or Figure 10 This is discussed in stage 1075. For example, the first UE can determine the differential distance and (R) for each pair of sidelink UEs, including the reference sidelink UE and another sidelink UE. sum_diff_j ),like Figure 8 As discussed herein, the components used to determine the distance of the reference sidelink UE and the difference between the distance and the sum of distances from each of the plurality of sidelink UEs may include, for example, one or more processors 1102, which have dedicated hardware or implement executable code or software instructions in the memory 1104 and / or media 1120 of the UE 1100, such as... Figure 11 The differential distance and module 1132 are shown.

[0198] The first UE can also receive, along with the time difference measured by the corresponding sidelink UE, the identifier of the network entity, the identifier of the second reference signal received from the network entity, the identifier of the sidelink reference signal received from the first UE, and the identifier of the sidelink UE, for example, as in Figure 9 Phases 960 and 965 or Figure 10 The first UE may also receive a timestamp having a time difference measured by the corresponding sidelink UE, as discussed in stage 1060. Figure 9 Stages 960 and 965 or Figure 10 The process discussed in stage 1060. Components for receiving, along with the time difference measured by the corresponding sidelink UE, the identifier of the network entity, the identifier of the second reference signal received from the network entity, the identifier of the sidelink reference signal received from the first UE, and the identifier of the sidelink UE, and components for receiving a timestamp having the time difference measured by the corresponding sidelink UE, may include, for example, a wireless transceiver 1110 or wireless transceiver 1112 and one or more processors 1102, the one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in the memory 1104 and / or medium 1120 in the UE 1100, such as... Figure 11 The report module 1128 shown.

[0199] In one example, the first UE can receive the identifier of the reference sidelink UE from the location server, for example, as in Figure 9 Phase 912 and Figure 10 The components discussed in phase 1012 may include, for example, a wireless transceiver 1110 or 1112 and one or more processors 1102, which have dedicated hardware or implement executable code or software instructions in memory 1104 and / or media 1120 in the UE 1100, such as... Figure 11 The reference SL UE module 1134 is shown.

[0200] For example, the first UE can determine its location using differential distance and at least in part based on its group delay calibration state, for example, as... Figure 9 Phase 910 and Figure 10 The components discussed in phase 1010, used to determine the location of the first UE based at least in part on the group delay calibration state of the first UE, may include, for example, one or more processors 1102, which have dedicated hardware or implement executable code or software instructions in memory 1104 and / or media 1120 in the UE 1100, such as... Figure 11a group delay state module 1136 as shown in FIG. 11.

[0201] In one implementation, the first UE can also determine the position of the first UE based at least in part on the differential range- sums of the plurality of sidelink UEs, e.g., as discussed in stage 980 of Figure 9 FIG. 11. For example, the position of the first UE can be determined based on an intersection of a hyperbola or hyperboloid resulting from the differential range-sums with the positions of the sidelink UEs in a UE-based positioning procedure, e.g., as discussed in stage 980 of Figure 8 and Figure 9 FIG. 11. Means for determining the position of the first UE based at least in part on the differential range-sums of the plurality of sidelink UEs can include, for example, the one or more processors 1102 with dedicated hardware or implementing executable code or software instructions in the memory 1104 and / or media 1120 of the UE 1100, e.g., a positioning module 1138 as shown in Figure 11 FIG. 11.

[0202] For example, the first UE can receive assistance data including a position of a network entity and a position of the sidelink UE, where the position of the first UE is determined further based on the position of the network entity and the position of the sidelink UE, e.g., as discussed in stage 925 of Figure 9 FIG. 11. Means for receiving assistance data including a position of a network entity and a position of the sidelink UE, where the position of the first UE is determined further based on the position of the network entity and the position of the sidelink UE, can include, for example, the wireless transceiver 1110 or wireless transceiver 1112 and the one or more processors 1102 with dedicated hardware or implementing executable code or software instructions in the memory 1104 and / or media 1120 of the UE 1100, e.g., an assistance data module 1140 as shown in Figure 11 FIG. 11.

[0203] In one implementation, the first UE can transmit the differential range-sums of the plurality of sidelink UEs to a location server, where the position of the first UE is determined by the location server based at least in part on the differential range-sums of the plurality of sidelink UEs, e.g., as discussed in stage 1078 of Figure 10 FIG. 11. Means for transmitting the differential range-sums of the plurality of sidelink UEs to a location server, where the position of the first UE is determined by the location server based at least in part on the differential range-sums of the plurality of sidelink UEs, can include, for example, the wireless transceiver 1110 or wireless transceiver 1112 and the one or more processors 1102 with dedicated hardware or implementing executable code or software instructions in the memory 1104 and / or media 1120 of the UE 1100, e.g., a reporting module 1128 as shown in Figure 1 FIG. 11.

[0204] For example, the first UE can send the differential distances of multiple sidelink UEs and the identifier of the network entity, the identifier of the first reference signal received from the network entity, the identifiers of one or more sidelink reference signals sent to the multiple sidelink UEs, the identifier of the first UE, and the identifier of each sidelink UE together to the location server, for example, such as Figure 10 The first UE can also transmit timestamps with differential distances and sums of multiple sidelink UEs, as discussed in stage 1078. Figure 10 The process discussed in stage 1078 includes components for transmitting the differential distance sum of multiple sidelink UEs, along with the identifier of a network entity, the identifier of a first reference signal received from the network entity, the identifier of one or more sidelink reference signals sent to the multiple sidelink UEs, the identifier of the first UE, and the identifier of each sidelink UE, to a location server; and components for transmitting a timestamp having the differential distance sum of the multiple sidelink UEs. These components may include, for example, a wireless transceiver 1110 or wireless transceiver 1112 and one or more processors 1102, the one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in the memory 1104 and / or medium 1120 of the UE 1100, such as... Figure 11 The report module 1128 shown.

[0205] In one implementation, processing the Rx-Tx time difference associated with each sidelink UE to generate a differential distance sum for a plurality of sidelink UEs may include, for example, sending the Rx-Tx time difference associated with each sidelink UE to a location server, wherein the differential distance sum for the plurality of sidelink UEs is determined by the location server based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE, and wherein the location of the first UE is determined by the location server at least in part based on the differential distance sum for the plurality of sidelink UEs, for example, as Figure 10 The components discussed in stages 1065, 1070, and 1080 are for transmitting the Rx-Tx time difference associated with each sidelink UE to a location server, wherein the differential distance sum of the plurality of sidelink UEs is determined by the location server based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE, and wherein the location of a first UE is determined by the location server at least in part based on the differential distance sum of the plurality of sidelink UEs. These components may include, for example, a wireless transceiver 1110 or wireless transceiver 1112 and one or more processors 1102, the one or more processors 1102 having dedicated hardware or implementing executable code or software instructions in the memory 1104 and / or medium 1120 of the UE 1100, such as... Figure 11The reporting module 1128 shown in FIG. 11.

[0206] For example, the first UE can transmit, to the location server, the Rx-Tx time difference associated with each sidelink UE together with an identifier of the network entity, an identifier of the first reference signal received from the network entity, an identifier of the one or more sidelink reference signals transmitted to the plurality of sidelink UEs, an identifier of the first UE, and an identifier of each sidelink UE, e.g., as discussed in stage 1065 of FIG. 10. Figure 10 The first UE can also transmit a timestamp with the Rx-Tx time difference associated with each sidelink UE, e.g., as discussed in stage 1065 of FIG. 10. Figure 10 The means for transmitting, to the location server, the Rx-Tx time difference associated with each sidelink UE together with an identifier of the network entity, an identifier of the first reference signal received from the network entity, an identifier of the one or more sidelink reference signals transmitted to the plurality of sidelink UEs, an identifier of the first UE, and an identifier of each sidelink UE, the means for transmitting a timestamp with the Rx-Tx time difference associated with each sidelink UE, can include, for example, the wireless transceiver 1110 or the wireless transceiver 1112 and the one or more processors 1102 with dedicated hardware or implementing executable code or software instructions in the memory 1104 and / or the medium 1120 of the UE 1100, e.g., the reporting module 1128 shown in FIG. 11. Figure 11 The reporting module 1128 shown in FIG. 11.

[0207] In one implementation, the first UE can transmit, to the location server, a group delay calibration status of the first UE, where the position of the first UE is determined using the differential range-sum of the plurality of sidelink UEs based at least in part on the group delay calibration status of the first UE, e.g., as discussed in stage 1010 of FIG. 9. Figure 10 For example, the group delay calibration status of the first UE can include an indication of whether the group delay of the first UE is calibrated. For example, the group delay calibration status of the first UE can include calibration error statistics of the group delay of the first UE. The group delay calibration status of the first UE can be transmitted to the location server periodically, aperiodically, triggered by an event, or a combination thereof. The means for transmitting, to the location server, the group delay calibration status of the first UE, where the position of the first UE is determined using the differential range-sum of the plurality of sidelink UEs based at least in part on the group delay calibration status of the first UE, can include, for example, the wireless transceiver 1110 or the wireless transceiver 1112 and the one or more processors 1102 with dedicated hardware or implementing executable code or software instructions in the memory 1104 and / or the medium 1120 of the UE 1100, e.g., the reporting module 1128 shown in FIG. 9. Figure 11The illustrated group delay state module 1136 and reporting module 1128.

[0208] Figure 14 A flowchart of an example method 1400 for determining a location of a first UE in a wireless network is shown, the method being performed by a location server in a manner consistent with the disclosed embodiments. The location server can be, for example Figure 1 The illustrated location server 160 or Figure 2 The illustrated LMF 220, Figure 8 and Figure 9 The illustrated location server 804 or Figure 12 The illustrated location server 1200.

[0209] At block 1402, the location server obtains differential range sums for the first UE and a plurality of sidelink UEs based on a receive-transmit (Rx-Tx) time difference associated with each sidelink UE measured by the first UE, where the Rx-Tx time difference associated with each sidelink UE is a time difference measured by the first UE between receiving a first reference signal from a network entity and transmitting a sidelink reference signal to the respective sidelink UE, where the differential range sums for the first UE and the plurality of sidelink UEs are further based on time differences measured by the plurality of sidelink UEs, where the time difference measured by each sidelink UE is a time difference between receiving a sidelink reference signal from the first UE and receiving a second reference signal from the network entity, where each differential range sum is a difference between a range sum for a reference sidelink UE from the plurality of sidelink UEs and a range sum for another sidelink UE from the plurality of sidelink UEs, and where the range sum for each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE, e.g., as discussed in stages 1070 or 1078 in FIG. 11. Figure 10 For example, the Rx-Tx time difference associated with each sidelink UE can be determined by the first UE, e.g., as a Rx-Tx time difference (T UE_Rx→Tx_i ), e.g., as described in FIG. 11. Figure 8 For example, the time difference measured by each sidelink UE is a time difference (T Rx_sidelink_i -T Rx_RS_i ), e.g., as described in FIG. 11. Figure 8The means for obtaining the differential range sums for the first UE and the plurality of sidelink UEs based on the receive-transmit (Rx-Tx) time differences associated with each sidelink UE measured by the first UE, where the Rx-Tx time difference associated with each sidelink UE is a time difference measured by the first UE between receiving a first reference signal from the network entity and transmitting a sidelink reference signal to the respective sidelink UE, where the differential range sums for the first UE and the plurality of sidelink UEs are further based on time differences measured by the plurality of sidelink UEs, where the time difference measured by each sidelink UE is a time difference between receiving a sidelink reference signal from the first UE and receiving a second reference signal from the network entity, where each differential range sum is a difference between a range sum for a reference sidelink UE from the plurality of sidelink UEs and a range sum for another sidelink UE from the plurality of sidelink UEs, and where the range sum for each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE, can include, for example, the external interface 1210 and the one or more processors 1202 with dedicated hardware or executable code or software instructions implemented in the memory 1204 and / or the medium 1220 in the location server 1200, for example Figure 12 the reporting module 1222 and / or the range sum module 1224 and the differential range sum module 1226 shown in FIG. 12.

[0210] At block 1404, the location server determines a position of the first UE based at least in part on the differential range sums for the plurality of sidelink UEs, for example, as discussed at stage 1080 of Figure 10 FIG. 13. For example, the location server determines the position of the first UE further based on a position of the network entity and positions of the sidelink UEs. For example, the position of the first UE can be determined in a UE-assisted positioning procedure based on an intersection of a hyperbola or hyperboloid resulting from the differential range sums with the positions of the sidelink UEs, for example, as discussed at stage 1080 of Figure 8 and Figure 10 FIG. 13. The means for determining the position of the first UE based at least in part on the differential range sums for the plurality of sidelink UEs can include, for example, the one or more processors 1202 with dedicated hardware or executable code or software instructions implemented in the memory 1204 and / or the medium 1220 of the location server 1200, for example Figure 12 the positioning module 1228 shown in FIG. 12.

[0211] In one implementation, the location server obtains the Rx-Tx time differences associated with each sidelink UE from the first UE (e.g., as discussed at stage 1065 of Figure 10 FIG. 13), and receives the time differences measured by each sidelink UE (e.g., as discussed at stage 1070 of Figure 10(As discussed in stage 1060), to obtain the differential distance sum between the first UE and multiple sidelink UEs. The location server determines the differential distance sum between the first UE and multiple sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE, for example, as... Figure 10 The components discussed in phase 1070, including those for receiving the Rx-Tx time difference associated with each sidelink UE from the first UE and for receiving the time difference measured by each sidelink UE, may include, for example, an external interface 1210 and one or more processors 1202, the processors 1202 having dedicated hardware or implementing executable code or software instructions in memory 1204 and / or media 1220 in the location server 1200, such as... Figure 12 The reporting module 1222 shown. Components for determining the differential distance sum of the first UE and multiple sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE may include, for example, one or more processors 1102, which have dedicated hardware or implement executable code or software instructions in the memory 1204 and / or media 1220 of the location server 1200, such as... Figure 12 The distance and module 1224 and the differential distance and module 1226 are shown.

[0212] For example, a location server can determine a differential distance sum by determining the distance sum for each sidelink UE based on the Rx-Tx time difference associated with the corresponding sidelink UE and the time difference measured by the corresponding sidelink UE, for example, as... Figure 10 This is discussed in stage 1070. For example, the location server can determine the distance (R) of each of multiple sidelink UEs 820. sum As discussed in Phase 8. The components used to determine the differential distance sum by determining the distance for each sidelink UE based on the Rx-Tx time difference associated with the respective sidelink UE and the time difference measured by the respective sidelink UE may include, for example, one or more processors 1202, which have dedicated hardware or implement executable code or software instructions in memory 1204 and / or media 1220 in the location server 1200, such as... Figure 12 The distance and module 1224 are shown. The location server can also determine the difference between the distance and sum of the reference sidelink UE and the distance and sum of each other sidelink UE from multiple sidelink UEs, for example, as... Figure 10 This is discussed in stage 1070. For example, the location server can determine the differential distance and (R) for each pair of sidelink UEs, including a reference sidelink UE and another sidelink UE. sum_diff_j ),like Figure 8 As discussed herein, the components used to determine the distance of the reference sidelink UE and the difference between the distance and the sum of distances from each of the plurality of sidelink UEs may include, for example, one or more processors 1202, which have dedicated hardware or implement executable code or software instructions in the memory 1204 and / or media 1220 of the location server 1200, such as... Figure 12 The differential distance and module 1226 are shown.

[0213] The location server may also receive, along with the Rx-Tx time difference associated with the first UE and each sidelink UE, the identifier of the network entity, the identifier of the first reference signal received from the network entity, the identifiers of one or more sidelink reference signals sent to the multiple sidelink UEs, the identifier of the first UE, and the identifier of each sidelink UE, for example, such as Figure 10 As discussed in phase 1065. The location server may also receive timestamps with Rx-Tx time differences associated with each sidelink UE, for example, as discussed in phase 1065.

[0214] The location server can also receive, along with the time difference measured by the corresponding sidelink UE, the identifier of the network entity, the identifier of the second reference signal received from the network entity, the identifier of the sidelink reference signal received from the first UE, and the identifier of the sidelink UE, for example, such as Figure 10 The location server can also receive from each sidelink UE a timestamp with the time difference measured by the corresponding sidelink UE, as discussed in stage 1060. Figure 10 The stage 1060 discussed.

[0215] In one implementation, the location server obtains the differential distance sum between the first UE and multiple sidelink UEs by receiving the differential distance sum from the first UE, for example, as... Figure 10 The components discussed in stage 1078 may include, for example, an external interface 1210 and one or more processors 1202, which have dedicated hardware or implement executable code or software instructions in memory 1204 and / or media 1220 in location server 1200, such as... Figure 12 The report module 1222 is shown.

[0216] The location server can receive the identifier of the network entity from the first UE along with the differential distance, the identifier of the first reference signal received from the network entity, the identifiers of one or more sidelink reference signals sent to multiple sidelink UEs, the identifier of the first UE, and the identifier of each sidelink UE, and send them to the location server together, for example, as... Figure 10 The phase 1078 discussed. The location server can also receive a timestamp with differential distance from the first UE, for example, as in Figure 10 The stage discussed in 1078.

[0217] In one implementation, the location server may also receive from each sidelink UE an indication of the signal strength of the signal from the first UE measured by each corresponding sidelink UE, for example, such as Figure 10 The components discussed in stage 1012. The components used to indicate the signal strength of a signal from a first UE, measured by each respective sidelink UE, may include, for example, an external interface 1210 and one or more processors 1202, the one or more processors 1202 having dedicated hardware or implementing executable code or software instructions in memory 1204 and / or media 1220 in the location server 1200, for example... Figure 12 The reporting module 1222 and the reference SL UE module 1230 are shown. The location server can determine the reference sidelink UE based at least in part on an indication of the signal strength of the signal from the first UE measured by each corresponding sidelink UE, for example, as... Figure 10 The process discussed in stage 1012. Components for determining a reference sidelink UE based at least in part on an indication of the signal strength of a signal from the first UE measured by each respective sidelink UE may include, for example, one or more processors 1202, which have dedicated hardware or implement executable code or software instructions in memory 1204 and / or media 1220 in the location server 1200, such as... Figure 12 The reference SL UE module 1230 is shown. The location server can send the identifier of the reference sidelink UE to the first UE, for example, such as... Figure 10 The components discussed in phase 1012 may include, for example, an external interface 1210 and one or more processors 1202, which have dedicated hardware or implement executable code or software instructions in memory 1204 and / or media 1220 in location server 1200, such as... Figure 12 The report module 1222 and the reference SLUE module 1230 are shown.

[0218] The location server can also receive the group delay calibration status of the first UE from the first UE, for example, such as Figure 10As discussed in stage 1010, components for receiving the group delay calibration status of the first UE from the first UE may include, for example, an external interface 1210 and one or more processors 1202, the one or more processors 1202 having dedicated hardware or implementing executable code or software instructions in memory 1204 and / or media 1220 in the location server 1200, for example... Figure 12 The reporting module 1222 and group delay status module 1232 are shown. For example, the group delay calibration status of the first UE may include an indication of whether the group delay of the first UE has been calibrated. The group delay calibration status of the first UE may include calibration error statistics of the group delay of the first UE. The group delay calibration status of the first UE may be received from the first UE periodically, non-periodically, by event triggering, or a combination thereof. The location server may determine the location of the first UE using the differential distance of multiple sidelink UEs and at least in part based on the group delay calibration status of the first UE, for example, as... Figure 10 The components discussed in phase 1010 for determining the differential distance of multiple side-link UEs and determining the location of the first UE based at least in part on the group delay calibration state of the first UE may include, for example, an external interface 1210 and one or more processors 1202, the one or more processors 1202 having dedicated hardware or implementing executable code or software instructions in memory 1204 and / or media 1220 in the location server 1200, such as... Figure 12 The report module 1222 and the group delay status module 1232 are shown.

[0219] Figure 15 A flowchart is shown of an exemplary method 1500 for determining the location of a first UE in a wireless network, the method being performed by a location server in a manner consistent with the disclosed implementation. The location server may be, for example... Figure 1 The location server shown is 160 or Figure 2 The LMF 220 shown Figure 8 and Figure 9 The location server shown is 804 or Figure 12 The location server shown is 1200.

[0220] In box 1502, the location server receives time differences measured by multiple sidelink UEs, wherein the time difference measured by each sidelink UE is the time difference between receiving a sidelink reference signal from a first UE and receiving a reference signal from a network entity, for example, as... Figure 9The phase 960 discussed. For example, the time difference measured by each sidelink UE is the time difference (T) between the reception (e.g., ToA) of the reference signal 860 transmitted by the base station 802 and the reception (e.g., ToA) of the sidelink reference signal 870i transmitted by the first UE 810, as measured by each sidelink UE 820i. Rx_sidelink_i -T Rx_RS_i For example, such as Figure 8 The component discussed herein is for receiving time differences measured by multiple sidelink UEs, wherein the time difference measured by each sidelink UE is the time difference between receiving a sidelink reference signal from a first UE and receiving a reference signal from a network entity. This component may include, for example, an external interface 1210 and one or more processors 1202, the one or more processors 1202 having dedicated hardware or implementing executable code or software instructions in memory 1204 and / or media 1220 in location server 1200, for example... Figure 12 The report module 1222 is shown.

[0221] In box 1504, the location server sends time differences measured by multiple sidelink UEs to the first UE to determine the location of the first UE based on the time differences measured by the multiple sidelink UEs and the receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is the time difference measured by the first UE between receiving a second reference signal from a network entity and transmitting a sidelink reference signal to the corresponding sidelink UE, for example, as in Figure 9 The phases 965 and 970 are discussed. For example, the Rx-Tx time difference associated with each sidelink UE can be determined by the first UE as the Rx-Tx time difference (T) between the reception (e.g., measured ToA) of the reference signal 850 and the transmission (e.g., measured ToD) of the sidelink reference signal 870i sent to the corresponding sidelink UE 820i. UE_Rx→Tx_i For example, such as Figure 8 As described in [the document]. A component for transmitting to a first UE time differences measured by multiple sidelink UEs to determine the location of the first UE based on the time differences measured by the multiple sidelink UEs and the receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is the time difference measured by the first UE between receiving a second reference signal from a network entity and transmitting a sidelink reference signal to the corresponding sidelink UE. This component may include, for example, an external interface 1210 and one or more processors 1202, the one or more processors 1202 having dedicated hardware or implementing executable code or software instructions in memory 1204 and / or media 1220 in the location server 1200, such as... Figure 12 The report module 1222 is shown.

[0222] In one implementation, the location server may also send auxiliary data to the first UE, including at least the location of network entities, such as... Figure 9 As discussed in stage 925. For example, the auxiliary data may also include the location of each sidelink UE. Components for sending auxiliary data, including at least the location of network entities, to the first UE may include, for example, an external interface 1210 and one or more processors 1202, the one or more processors 1202 having dedicated hardware or implementing executable code or software instructions in memory 1204 and / or media 1220 in the location server 1200, such as... Figure 12 The auxiliary data module 1234 is shown.

[0223] In one implementation, the location server may receive, along with time differences measured by a plurality of sidelink UEs, an identifier of a network entity, an identifier of a second reference signal received from the network entity, an identifier of a sidelink reference signal received from a first UE, and an identifier of a sidelink UE, for example, as discussed in stage 960. The location server may also receive timestamps having time differences measured by a plurality of sidelink UEs, for example, as discussed in stage 960.

[0224] In one implementation, the first UE determines a differential distance sum of multiple sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE, wherein each differential distance sum is the difference between the distance sum of a reference sidelink UE from the multiple sidelink UEs and the distance sum of another sidelink UE from the multiple sidelink UEs, and wherein the distance sum of each sidelink UE is the sum of a first distance between the first UE and the network entity and a second distance between the first UE and the corresponding sidelink UE, for example, as... Figure 8 and Figure 9 The stage 970 discussed.

[0225] For example, the location server can also receive from each sidelink UE an indication of the signal strength of the signal from the first UE, measured by each corresponding sidelink UE, such as... Figure 10 The components discussed in stage 1012. The components used to indicate the signal strength of a signal from a first UE, measured by each respective sidelink UE, may include, for example, an external interface 1210 and one or more processors 1202, the one or more processors 1202 having dedicated hardware or implementing executable code or software instructions in memory 1204 and / or media 1220 in the location server 1200, for example... Figure 12The reporting module 1222 and the reference SL UE module 1230 are shown. The location server can determine the reference sidelink UE based at least in part on an indication of the signal strength of the signal from the first UE measured by each corresponding sidelink UE, for example, as... Figure 10 The process discussed in stage 1012. Components for determining a reference sidelink UE based at least in part on an indication of the signal strength of a signal from the first UE measured by each respective sidelink UE may include, for example, one or more processors 1202, which have dedicated hardware or implement executable code or software instructions in memory 1204 and / or media 1220 in the location server 1200, such as... Figure 12 The reference SL UE module 1230 is shown. The location server can send the identifier of the reference sidelink UE to the first UE, for example, such as... Figure 10 The components discussed in phase 1012 may include, for example, an external interface 1210 and one or more processors 1202, which have dedicated hardware or implement executable code or software instructions in memory 1204 and / or media 1220 in location server 1200, such as... Figure 12 The report module 1222 and the reference SLUE module 1230 are shown.

[0226] Figure 16 A flowchart of an exemplary method 1600 performed by a first UE is shown, which is used to determine the location of a second UE in a wireless network in a manner consistent with the disclosed implementation. The first UE may be a sidelink UE or an advanced UE, for example... Figure 1 and Figure 2 The UE 105 shown Figure 8 , Figure 9 and Figure 10 The side-link UE 820 shown Figure 11 The UE 1100 shown is operating as a side-link UE, and the second UE can be a target UE or a lightweight UE.

[0227] In box 1602, the first UE receives a first reference signal from a network entity, for example, such as Figure 9 Phase 940 and Figure 10 This is discussed in stage 1040. For example, the reference signal could be a DL PRS signal used for positioning or other DL reference signals, such as... Figure 8 The reference signal 850 shown is a network entity that can be a base station, such as an eNB or gNB, or an access point, and is shown as... Figure 8 , Figure 9 and Figure 10The means for receiving the first reference signal from the network entity can include, for example, wireless transceiver 1110 or wireless transceiver 1112, and one or more processors 1102 with dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120 in UE 1100, e.g., reference signal reception module 1122 as illustrated. Figure 11 The means for receiving the first reference signal from the network entity can include, for example, wireless transceiver 1110 or wireless transceiver 1112, and one or more processors 1102 with dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120 in UE 1100, e.g., reference signal reception module 1122 as illustrated.

[0228] At block 1604, the first UE can receive a sidelink reference signal from the second UE, e.g., as discussed at stage 945 and Figure 9 stage 1045 in FIG. 10. For example, the sidelink reference signal can be a SL-PRS or SL-CSI-RS for positioning, e.g., reference signal 860 as illustrated. Figure 10 The means for receiving the sidelink reference signal from the second UE can include, for example, wireless transceiver 1110 or wireless transceiver 1112, and one or more processors 1102 with dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120 in UE 1100, e.g., reference signal reception module 1122 as illustrated. Figure 8 The means for receiving the sidelink reference signal from the second UE can include, for example, wireless transceiver 1110 or wireless transceiver 1112, and one or more processors 1102 with dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120 in UE 1100, e.g., reference signal reception module 1122 as illustrated. Figure 11

[0229] At block 1606, the first UE determines a time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity, e.g., as discussed at stage 950 and Figure 9 stage 1050 in FIG. 10. For example, the time difference measured by the first UE is the time difference (T Figure 10 ) between reception (e.g., ToA) of the reference signal 860 transmitted by the base station 802 and reception (e.g., ToA) of the sidelink reference signal 870i transmitted by the second UE 810, e.g., as discussed in FIG. 10. Rx_sidelink_i -T Rx_RS_i The means for determining the time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity can include, for example, one or more processors 1102 with dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120 in UE 1100, e.g., time difference module 1126 as illustrated. Figure 8 The means for determining the time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity can include, for example, one or more processors 1102 with dedicated hardware or implementing executable code or software instructions in memory 1104 and / or medium 1120 in UE 1100, e.g., time difference module 1126 as illustrated. Figure 11

[0230] ​​At block 1608, the first UE processes the time difference between receiving the sidelink reference signals from the second UE and receiving the first reference signal from the network entity to generate differential range sums for the second UE and a plurality of sidelink UEs including the first UE based on a receive-transmit (Rx-Tx) time difference associated with each sidelink UE measured by the second UE, where the Rx-Tx time difference associated with each sidelink UE is a time difference measured by the second UE between receiving a second reference signal from the network entity and transmitting a sidelink reference signal to the respective sidelink UE, where the differential range sums for the second UE and the plurality of sidelink UEs are further based on the time differences measured by the plurality of sidelink UEs, where each differential range sum is a difference between a range sum for a reference sidelink UE from the plurality of sidelink UEs and a range sum for another sidelink UE from the plurality of sidelink UEs, and where the range sum for each sidelink UE is a sum of a first distance between the second UE and the network entity and a second distance between the second UE and the respective sidelink UE, and where a location of the second UE is determined based at least in part on the differential range sums for the plurality of sidelink UEs, e.g., as discussed in stages 960 and 1060 of FIGS. 9 and 10, respectively, of Figure 9 . In one example, the first UE can process the time difference between receiving the sidelink reference signals from the second UE and receiving the first reference signal from the network entity to generate the differential range sums by preparing a report and sending the time difference to the second UE or a location server to generate the differential range sums, e.g., as discussed in Figure 10 . In one example, the first UE can process the time difference between receiving the sidelink reference signals from the second UE and receiving the first reference signal from the network entity to generate the differential range sums by preparing a report and sending the time difference to the second UE or a location server to generate the differential range sums, e.g., as discussed in Figure 8 . For example, the Rx-Tx time difference associated with each sidelink UE can be determined as a Rx-Tx time difference (T UE_Rx→Tx_i ), e.g., as discussed in Figure 9 . In one example, the first UE can process the time difference between receiving the sidelink reference signals from the second UE and receiving the first reference signal from the network entity to generate the differential range sums by preparing a report and sending the time difference to the second UE or a location server to generate the differential range sums, e.g., as discussed in Figure 10 . In one example, the first UE can process the time difference between receiving the sidelink reference signals from the second UE and receiving the first reference signal from the network entity to generate the differential range sums by preparing a report and sending the time difference to the second UE or a location server to generate the differential range sums, e.g., as discussed in Figure 8The means for processing the time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity to generate differential range sums for the second UE and a plurality of sidelink UEs including the first UE based on a receive-transmit (Rx-Tx) time difference associated with each sidelink UE measured by the second UE, where the Rx-Tx time difference associated with each sidelink UE is a time difference measured by the second UE between receiving a second reference signal from the network entity and transmitting a sidelink reference signal to the respective sidelink UE, where the differential range sums for the second UE and the plurality of sidelink UEs are further based on the time differences measured by the plurality of sidelink UEs, where each differential range sum is a difference between a range sum for a reference sidelink UE from the plurality of sidelink UEs and a range sum for another sidelink UE from the plurality of sidelink UEs, and where the range sum for each sidelink UE is a sum of a first distance between the second UE and the network entity and a second distance between the second UE and the respective sidelink UE, and where the position of the second UE is determined based at least in part on the differential range sums for the plurality of sidelink UEs, can include, for example, the wireless transceiver 1110 or the wireless transceiver 1112 and the one or more processors 1102 with dedicated hardware or executable code or software instructions implemented in the memory 1104 and / or the medium 1120 in the UE 1100, for example Figure 11 as shown by the reporting module 1128.

[0231] For example, in one implementation, processing the time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity to generate the differential range sums includes transmitting the time difference to a location server, for example, as shown by stage 960 of Figure 9 and stage 1060 of Figure 10 In one example, the differential range sums are determined by the location server and the position of the second UE is determined by the location server based on the differential range sums, for example, as shown by stage 970 of Figure 10 In one example, the location server transmits the time difference to the second UE and the second UE determines the differential range sums and determines the position of the second UE based on the differential range sums, for example, as shown by stage 1060 of Figure 9 The means for transmitting the time difference to the location server can include, for example, the wireless transceiver 1110 or the wireless transceiver 1112 and the one or more processors 1102 with dedicated hardware or executable code or software instructions implemented in the memory 1104 and / or the medium 1120 of the UE 1100, for example Figure 11 as shown by the reporting module 1128.

[0232] For example, in one implementation, processing the time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity to generate the differential range sum includes transmitting the time difference to the second UE, e.g., as discussed in stage 960 of FIG. 9 and stage 1060 of FIG. 10. In one example, the second UE determines the differential range sum and the location server determines the location of the second UE based on the differential range sum, e.g., as discussed in stage 960 of FIG. 9 and stage 1060 of FIG. 10. In one example, the second UE determines the differential range sum and determines the location of the second UE based on the differential range sum, e.g., as discussed in stage 960 of FIG. 9 and stage 1060 of FIG. 10. The means for transmitting the time difference to the second UE can include, for example, the wireless transceiver 1110 or wireless transceiver 1112 and the one or more processors 1102 with dedicated hardware or implementing executable code or software instructions in the memory 1104 and / or media 1120 of the UE 1100, e.g., the reporting module 1128 as discussed in stage 960 of FIG. 9 and stage 1060 of FIG. 10. Figure 9 Figure 10 Figure 10 Figure 9 The means for transmitting the time difference to the second UE can include, for example, the wireless transceiver 1110 or wireless transceiver 1112 and the one or more processors 1102 with dedicated hardware or implementing executable code or software instructions in the memory 1104 and / or media 1120 of the UE 1100, e.g., the reporting module 1128 as discussed in stage 960 of FIG. 9 and stage 1060 of FIG. 10. Figure 11

[0233] In one implementation, processing the time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity to generate the differential range sum includes transmitting the time difference to the second UE, e.g., as discussed in stage 960 of FIG. 9 and stage 1060 of FIG. 10. In one example, the second UE determines the differential range sum and the location server determines the location of the second UE based on the differential range sum, e.g., as discussed in stage 960 of FIG. 9 and stage 1060 of FIG. 10. In one example, the second UE determines the differential range sum and determines the location of the second UE based on the differential range sum, e.g., as discussed in stage 960 of FIG. 9 and stage 1060 of FIG. 10. The means for transmitting the time difference to the second UE can include, for example, the wireless transceiver 1110 or wireless transceiver 1112 and the one or more processors 1102 with dedicated hardware or implementing executable code or software instructions in the memory 1104 and / or media 1120 of the UE 1100, e.g., the reporting module 1128 as discussed in stage 960 of FIG. 9 and stage 1060 of FIG. 10. Figure 9 Figure 10 Figure 9 Figure 10 The means for transmitting the time difference to the second UE can include, for example, the wireless transceiver 1110 or wireless transceiver 1112 and the one or more processors 1102 with dedicated hardware or implementing executable code or software instructions in the memory 1104 and / or media 1120 of the UE 1100, e.g., the reporting module 1128 as discussed in stage 960 of FIG. 9 and stage 1060 of FIG. 10. Figure 11

[0234] ​​​​​​​​The first UE can also measure a signal strength of the one or more signals received from the second UE and transmit an indication of the signal strength of the one or more signals received from the second UE to determine the reference sidelink UE based at least in part on the indications of the signal strength of the signals from the second UE measured by each sidelink UE including the first UE, e.g., as discussed in stage 912 in Figure 9 and stage 1012 in Figure 10 . The means for measuring a signal strength of the one or more signals received from the second UE can include, for example, the wireless transceiver 1110 or wireless transceiver 1112 and the one or more processors 1102 with dedicated hardware or executable code or software instructions implemented in the memory 1104 and / or medium 1120 in the UE 1100, e.g., the reference signal receiving module 1134 as shown in Figure 11 . The means for transmitting an indication of the signal strength of the one or more signals received from the second UE to determine the reference sidelink UE based at least in part on the indications of the signal strength of the signals from the second UE measured by each sidelink UE including the first UE can include, for example, the wireless transceiver 1110 or wireless transceiver 1112 and the one or more processors 1102 with dedicated hardware or executable code or software instructions implemented in the memory 1104 and / or medium 1120 in the UE 1100, e.g., the reference SL UE module 1134 as shown in Figure 11 .

[0235] It will be apparent to those skilled in the art that substantial variations can be made in form, detail, and use of the specific implementation without departing from the spirit of the subject matter. For example, customized hardware might also be used, and / or particular elements might be implemented in hardware, software (including portable software, such as applets, etc.), or both. Further, connection to other computing devices such as network input / output devices can be employed.

[0236] With reference to the appended figures, components of the present disclosure can include a memory that can include a non-transitory machine-readable medium. The terms "machine-readable medium" and "computer-readable medium" as used herein, refer to any storage medium that participates in providing instructions to a processing unit for execution. In the embodiments provided above, various machine-readable media might be involved in providing instructions to a processing unit and / or other device(s) for execution. Additionally or alternatively, the machine-readable media might be used to store and / or carry such instructions. In many implementations, a computer-readable medium is a physical and / or tangible storage medium. Such a medium can take many forms, including but not limited to, non-volatile media and volatile media. Common forms of computer-readable media include, for example, magnetic and / or optical media, any other physical medium with patterns of holes, a RAM, a programmable ROM (PROM), erasable PROM (EPROM), a FLASH- EPROM, any other memory chip or cartridge, or any other medium from which a computer can read instructions and / or code.

[0237] The methods, systems, and devices discussed herein are examples. Various embodiments can omit, substitute, or add various procedures or components as appropriate. For instance, features described with respect to certain embodiments can be combined in various other embodiments. Different aspects and elements of the embodiments can be combined in a similar manner. Also, the various components of the figures provided herein can be embodied in hardware and / or software. Furthermore, certain embodiments can comprise one or more computer-readable storage media storing instructions that, when executed by one or more processors, cause the one or more processors to perform operations.

[0238] It will be appreciated that, for clarity and the convenience of terminology, this signal is referred to as a bit, message, value, element, symbol, character, variable, term, number, numeral, etc., at times, primarily for common usage. However, it will be understood that all such or similar terms are to be associated with appropriate physical quantities and are merely convenient labels. Unless specifically stated otherwise, as apparent from the above discussion, it is appreciated that throughout the description, discussions utilizing terms such as "processing," "computing," "calculating," "determining," "identifying," "associating," "measuring," "performing," or the like, refer to the action and processes of a specific apparatus, such as a special purpose computer or a similar special purpose electronic computing device. In the context of this specification, therefore, a special purpose computer or a similar special purpose electronic computing device is capable of manipulating or transforming signals, typically, represented as physical electronic, electrical, or magnetic variables stored in memory, registers, or other information storage devices, transmission devices, or display devices of the special purpose computer or similar special purpose electronic computing device.

[0239] The terms "and" and "or" as used herein can include a variety of meanings that also are expected to depend, at least partly, upon the context in which these terms are used. Typically, "or" if used to associate a list, such as A, B, or C, is intended to mean A, B, and C, here used in the inclusive sense, as well as A, B, or C, here used in the exclusive sense. In addition, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in the singular or can be used to describe some 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. Furthermore, the term "at least one of' if used to associate a list, such as A, B, or C, can be interpreted in the alternative (A or B or C) or the

[0240] Having described several embodiments, various modifications, alternative constructions, and equivalents can be used without departing from the spirit of the disclosure. For example, the above elements can merely be a component of a larger system, wherein other rules can take precedence over, or otherwise modify, the use of the various embodiments. Additionally, a number of steps can be undertaken before, during, or after the above described elements are considered. As such, the above description does not limit the scope of the disclosure.

[0241] In view of this description, embodiments can include different combinations of features. Examples of implementations are described in the following numbered clauses:

[0242] Clause 1. A method performed by a first user equipment (UE) for determining a location of the first UE, the method comprising: receiving, from a network entity, a first reference signal; transmitting, to a plurality of sidelink UEs, one or more sidelink reference signals; determining a receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference between receiving the first reference signal from the network entity and transmitting the sidelink reference signal to the respective sidelink UE; and processing the Rx-Tx time difference associated with each sidelink UE based on the Rx-Tx time difference associated with each sidelink UE and a time difference measured by each sidelink UE to generate a differential range sum for the plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving the sidelink reference signal from the first UE and receiving a second reference signal from the network entity, each differential range sum is a difference between a range sum from a reference sidelink UE of the plurality of sidelink UEs and a range sum from another sidelink UE of the plurality of sidelink UEs, and wherein the range sum for each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE, wherein the location of the first UE is determined based at least in part on the differential range sums for the plurality of sidelink UEs.

[0243] Clause 2. The method of clause 1, further comprising: receiving a time difference measured by each of the plurality of sidelink UEs; wherein processing the Rx-Tx time difference associated with each sidelink UE to generate the differential range sum for the plurality of sidelink UEs comprises determining the differential range sum for the plurality of sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE.

[0244] Clause 3. The method of clause 2, wherein determining the differential range sum comprises: determining a range sum for each sidelink UE based on the Rx-Tx time difference associated with the respective sidelink UE and the time difference measured by the respective sidelink UE; and determining a difference between the range sum for the reference sidelink UE and the range sum for each other sidelink UE from the plurality of sidelink UEs.

[0245] Clause 4. The method of any of clauses 2 or 3, wherein the time difference measured by each sidelink UE is received directly from each sidelink UE.

[0246] Clause 5. The method of any of clauses 2 or 3, wherein the time difference measured by each sidelink UE is received from a location server.

[0247] Clause 6. The method of any of clauses 2 or 3, further comprising receiving, with the time difference measured by the respective sidelink UE, an identifier of a network entity, an identifier of a second reference signal received from the network entity, an identifier of a sidelink reference signal received from the first UE, and an identifier of the sidelink UE.

[0248] Clause 7. The method of clause 6, further comprising receiving a timestamp having the time difference measured by the respective sidelink UE.

[0249] Clause 8. The method of any of clauses 2-7, further comprising receiving, from a location server, an identifier of the reference sidelink UE.

[0250] Clause 9. The method of any of clauses 2-8, further comprising determining to use the differential range sum to determine the position of the first UE based at least in part on a group delay calibration status of the first UE.

[0251] Clause 10. The method of any of clauses 2-9, further comprising determining the position of the first UE based at least in part on the differential range sum for the plurality of sidelink UEs.

[0252] Clause 11. The method of clause 10, further comprising receiving assistance data comprising a position of the network entity and a position of the sidelink UE, wherein determining the position of the first UE is further based on the position of the network entity and the position of the sidelink UE.

[0253] Clause 12. The method of any of clauses 2 or 3, further comprising transmitting the differential range-sums of the plurality of sidelink UEs to a location server, wherein the location of the first UE is determined by the location server based at least in part on the differential range-sums of the plurality of sidelink UEs.

[0254] Clause 13. The method of clause 12, further comprising transmitting the differential range-sums of the plurality of sidelink UEs to the location server along with an identifier of the network entity, an identifier of the first reference signal received from the network entity, an identifier of the one or more sidelink reference signals transmitted to the plurality of sidelink UEs, an identifier of the first UE, and an identifier of each of the sidelink UEs.

[0255] Clause 14. The method of clause 13, further comprising transmitting a timestamp with the differential range-sums of the plurality of sidelink UEs.

[0256] Clause 15. The method of clause 1, wherein processing the Rx-Tx time difference associated with each of the sidelink UEs to generate the differential range-sums of the plurality of sidelink UEs comprises transmitting the Rx-Tx time difference associated with each of the sidelink UEs to a location server, wherein the differential range-sums of the plurality of sidelink UEs are determined by the location server based on the Rx-Tx time difference associated with each of the sidelink UEs and a time difference measured by each of the sidelink UEs, and wherein the location of the first UE is determined by the location server based at least in part on the differential range-sums of the plurality of sidelink UEs.

[0257] Clause 16. The method of clause 15, further comprising transmitting the Rx-Tx time difference associated with each of the sidelink UEs to the location server along with an identifier of the network entity, an identifier of the first reference signal received from the network entity, an identifier of the one or more sidelink reference signals transmitted to the plurality of sidelink UEs, an identifier of the first UE, and an identifier of each of the sidelink UEs.

[0258] Clause 17. The method of clause 16, further comprising transmitting a timestamp with the Rx-Tx time difference associated with each of the sidelink UEs.

[0259] Clause 18. The method of clause 15, further comprising transmitting a group delay calibration status of the first UE to the location server, wherein the location of the first UE is determined by the location server based at least in part on the group delay calibration status of the first UE using the differential range-sums of the plurality of sidelink UEs.

[0260] Clause 19. The method of clause 18, wherein the group delay calibration status of the first UE comprises an indication of whether a group delay of the first UE is calibrated.

[0261] Clause 20. The method of clause 18, wherein the group delay calibration status of the first UE comprises calibration error statistics of a group delay of the first UE.

[0262] Clause 21. The method of clause 20, wherein the group delay calibration status of the first UE is transmitted to the location server periodically, aperiodically, triggered by an event, or a combination thereof.

[0263] Clause 22. A first user equipment (UE) configured for determining a location of the first UE, the first UE comprising: at least one wireless transceiver configured to wirelessly communicate with other entities in a wireless network; at least one memory; and at least one processor coupled to the at least one wireless transceiver and the at least one memory and configured to: receive, via the at least one wireless transceiver, a first reference signal from a network entity; transmit, via the at least one wireless transceiver, one or more sidelink reference signals to a plurality of sidelink UEs; determine a receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference between receiving the first reference signal from the network entity and transmitting the sidelink reference signal to the respective sidelink UE; and process the Rx-Tx time difference associated with each sidelink UE based on the Rx-Tx time difference associated with each sidelink UE and a time difference measured by each sidelink UE to generate differential range sums for the plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving the sidelink reference signal from the first UE and receiving a second reference signal from the network entity, each differential range sum is a difference between a range sum from a reference sidelink UE of the plurality of sidelink UEs and a range sum from another sidelink UE of the plurality of sidelink UEs, and wherein the range sum for each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE, wherein the location of the first UE is determined based at least in part on the differential range sums for the plurality of sidelink UEs.

[0264] Clause 23. The first UE of clause 22, wherein the at least one processor is further configured to: receive, via the at least one wireless transceiver, the time difference measured by each sidelink UE of the plurality of sidelink UEs; wherein the at least one processor is configured to process the Rx-Tx time difference associated with each sidelink UE to generate the differential range sums for the plurality of sidelink UEs by being configured to determine the differential range sums for the plurality of sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE.

[0265] Clause 24. The first UE of clause 23, wherein the at least one processor is configured to determine the differential range-sums by being configured to: determine a range-sum for each sidelink UE based on a Rx-Tx time difference associated with the respective sidelink UE and the time difference measured by the respective sidelink UE; and determine a difference between the range-sum of the reference sidelink UE and the range-sum of each other sidelink UE from the plurality of sidelink UEs.

[0266] Clause 25. The first UE of any of clauses 23 or 24, wherein the time difference measured by each sidelink UE is received directly from each sidelink UE.

[0267] Clause 26. The first UE of any of clauses 23 or 24, wherein the time difference measured by each sidelink UE is received from a location server.

[0268] Clause 27. The first UE of any of clauses 23 or 24, wherein the at least one processor is further configured to receive, with the time difference measured by the respective sidelink UE, an identifier of a network entity, an identifier of a second reference signal received from the network entity, an identifier of a sidelink reference signal received from the first UE, and an identifier of the sidelink UE.

[0269] Clause 28. The first UE of clause 27, wherein the at least one processor is further configured to receive, via the at least one wireless transceiver, a timestamp with the time difference measured by the respective sidelink UE.

[0270] Clause 29. The first UE of any of clauses 23-28, wherein the at least one processor is further configured to receive, via the at least one wireless transceiver, an identifier of the reference sidelink UE from a location server.

[0271] Clause 30. The first UE of any of clauses 23-29, wherein the at least one processor is further configured to determine to use the differential range-sums to determine the location of the first UE based at least in part on a group delay calibration status of the first UE.

[0272] Clause 31. The first UE of any of clauses 23-30, wherein the at least one processor is further configured to determine the location of the first UE based at least in part on the differential range-sums of the plurality of sidelink UEs.

[0273] Clause 32. The first UE of clause 31, wherein the at least one processor is further configured to receive, via the at least one wireless transceiver, assistance data including a location of the network entity and a location of the sidelink UE, wherein determining the location of the first UE is further based on the location of the network entity and the location of the sidelink UE.

[0274] Clause 33. The first UE of any one of Clauses 23 or 24, wherein the at least one processor is further configured to transmit, via the at least one wireless transceiver, the differential range sums of the plurality of sidelink UEs to the location server, wherein the location of the first UE is determined by the location server based at least in part on the differential range sums of the plurality of sidelink UEs.

[0275] Clause 34. The first UE of Clause 33, wherein the at least one processor is further configured to transmit, to the location server, the differential range sums of the plurality of sidelink UEs together with an identifier of the network entity, an identifier of the first reference signal received from the network entity, an identifier of the one or more sidelink reference signals transmitted to the plurality of sidelink UEs, an identifier of the first UE, and an identifier of each sidelink UE.

[0276] Clause 35. The first UE of Clause 34, wherein the at least one processor is further configured to transmit, via the at least one wireless transceiver, a timestamp with the differential range sums of the plurality of sidelink UEs.

[0277] Clause 36. The first UE of Clause 22, wherein the at least one processor is configured to process the Rx-Tx time difference associated with each sidelink UE by being configured to transmit, to the location server, the Rx-Tx time difference associated with each sidelink UE to generate the differential range sums of the plurality of sidelink UEs, wherein the differential range sums of the plurality of sidelink UEs are determined by the location server based on the Rx-Tx time difference associated with each sidelink UE and a time difference measured by each sidelink UE, and wherein the location of the first UE is determined by the location server based at least in part on the differential range sums of the plurality of sidelink UEs.

[0278] Clause 37. The first UE of Clause 36, wherein the at least one processor is further configured to transmit, to the location server, the Rx-Tx time difference associated with each sidelink UE together with an identifier of the network entity, an identifier of the first reference signal received from the network entity, an identifier of the one or more sidelink reference signals transmitted to the plurality of sidelink UEs, an identifier of the first UE, and an identifier of each sidelink UE.

[0279] Clause 38. The first UE of Clause 37, wherein the at least one processor is further configured to transmit, via the at least one wireless transceiver, a timestamp with the Rx-Tx time difference associated with each sidelink UE.

[0280] Clause 39. The first UE of clause 36, wherein the at least one processor is further configured to transmit, via the at least one wireless transceiver, a group delay calibration status of the first UE to the location server, wherein the differential range sums of the plurality of sidelink UEs are determined based at least in part on the group delay calibration status of the first UE by the location server to determine the position of the first UE.

[0281] Clause 40. The first UE of clause 39, wherein the group delay calibration status of the first UE comprises an indication of whether a group delay of the first UE is calibrated.

[0282] Clause 41. The first UE of clause 39, wherein the group delay calibration status of the first UE comprises calibration error statistics of a group delay of the first UE.

[0283] Clause 42. The first UE of clause 41, wherein the group delay calibration status of the first UE is transmitted to the location server periodically, aperiodically, triggered by an event, or a combination thereof.

[0284] Clause 43. A first user equipment (UE) configured for determining a position of the first UE, the first UE comprising: means for receiving a first reference signal from a network entity; means for transmitting one or more sidelink reference signals to a plurality of sidelink UEs; means for determining a receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference between receiving the first reference signal from the network entity and transmitting the sidelink reference signal to the respective sidelink UE; and processing the Rx-Tx time difference associated with each sidelink UE based on the Rx-Tx time difference associated with each sidelink UE and a time difference measured by each sidelink UE to generate differential range sums of the plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving the sidelink reference signal from the first UE and receiving a second reference signal from the network entity, each differential range sum is a difference between a range sum from a reference sidelink UE of the plurality of sidelink UEs and a range sum from another sidelink UE of the plurality of sidelink UEs, and wherein the range sum of each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE, wherein the position of the first UE is determined based at least in part on the differential range sums of the plurality of sidelink UEs.

[0285] Clause 44. The first UE of clause 43, further comprising: means for receiving a time difference measured by each of the plurality of sidelink UEs; wherein the means for processing the Rx-Tx time difference associated with each sidelink UE to generate the differential range sum for the plurality of sidelink UEs determines the differential range sum for the plurality of sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE.

[0286] Clause 45. The first UE of clause 44, wherein the means for determining the differential range sum comprises: means for determining a range sum for each sidelink UE based on the Rx-Tx time difference associated with the respective sidelink UE and the time difference measured by the respective sidelink UE; and means for determining a difference between the range sum for the reference sidelink UE and the range sum for each other sidelink UE from the plurality of sidelink UEs.

[0287] Clause 46. The first UE of any of clauses 44 or 45, wherein the time difference measured by each sidelink UE is received directly from each sidelink UE.

[0288] Clause 47. The first UE of any of clauses 44 or 45, wherein the time difference measured by each sidelink UE is received from a location server.

[0289] Clause 48. The first UE of any of clauses 44 or 45, further comprising means for receiving, with the time difference measured by the respective sidelink UE, an identifier of a network entity, an identifier of a second reference signal received from the network entity, an identifier of a sidelink reference signal received from the first UE, and an identifier of the sidelink UE.

[0290] Clause 49. The first UE of clause 48, further comprising means for receiving a timestamp with the time difference measured by the respective sidelink UE.

[0291] Clause 50. The first UE of any of clauses 44-49, further comprising means for receiving, from a location server, an identifier of the reference sidelink UE.

[0292] Clause 51. The first UE of any of clauses 44-50, further comprising means for determining to use the differential range sum to determine a position of the first UE based at least in part on a group delay calibration status of the first UE.

[0293] Clause 52. The first UE of any of clauses 44-51, further comprising means for determining a position of the first UE based at least in part on the differential range sum for the plurality of sidelink UEs.

[0294] Clause 53. The first UE of clause 52, further comprising means for receiving assistance data comprising a location of the network entity and a location of the sidelink UE, wherein the means for determining the location of the first UE uses the location of the network entity and the location of the sidelink UE.

[0295] Clause 54. The first UE of any of clauses 44 or 45, further comprising means for sending a differential range sum of the plurality of sidelink UEs to a location server, wherein the location of the first UE is determined by the location server based at least in part on the differential range sum of the plurality of sidelink UEs.

[0296] Clause 55. The first UE of clause 54, further comprising means for sending the differential range sum of the plurality of sidelink UEs to the location server along with an identifier of the network entity, an identifier of the first reference signal received from the network entity, an identifier of the one or more sidelink reference signals transmitted to the plurality of sidelink UEs, an identifier of the first UE, and an identifier of each sidelink UE.

[0297] Clause 56. The first UE of clause 55, further comprising means for sending a timestamp with the differential range sum of the plurality of sidelink UEs.

[0298] Clause 57. The first UE of clause 43, wherein the means for processing the Rx-Tx time difference associated with each sidelink UE to generate a differential range sum of the plurality of sidelink UEs comprises means for sending the Rx-Tx time difference associated with each sidelink UE to a location server, wherein the differential range sum of the plurality of sidelink UEs is determined by the location server based on the Rx-Tx time difference associated with each sidelink UE and a time difference measured by each sidelink UE, and wherein the location of the first UE is determined by the location server based at least in part on the differential range sum of the plurality of sidelink UEs.

[0299] Clause 58. The first UE of clause 57, further comprising means for sending the Rx-Tx time difference associated with each sidelink UE to the location server along with an identifier of the network entity, an identifier of the first reference signal received from the network entity, an identifier of the one or more sidelink reference signals transmitted to the plurality of sidelink UEs, an identifier of the first UE, and an identifier of each sidelink UE.

[0300] Clause 59. The first UE of clause 58, further comprising means for sending a timestamp with the Rx-Tx time difference associated with each sidelink UE.

[0301] Clause 60. The first UE of clause 57, further comprising means for transmitting, to the location server, a group delay calibration status of the first UE, wherein the differential range sums of the plurality of sidelink UEs and the position of the first UE are determined based at least in part on the group delay calibration status of the first UE by the location server.

[0302] Clause 61. The first UE of clause 60, wherein the group delay calibration status of the first UE comprises an indication of whether a group delay of the first UE is calibrated.

[0303] Clause 62. The first UE of clause 60, wherein the group delay calibration status of the first UE comprises calibration error statistics of a group delay of the first UE.

[0304] Clause 63. The first UE of clause 62, wherein the group delay calibration status of the first UE is transmitted to the location server periodically, aperiodically, triggered by an event, or a combination thereof.

[0305] Clause 64. A non-transitory storage medium including program code stored thereon, the program code is operable to configure at least one processor in a first user equipment (UE) configured for determining a position of the first UE, the program code comprising instructions to: receive a first reference signal from a network entity; transmit one or more sidelink reference signals to a plurality of sidelink UEs; determine a receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference between receiving the first reference signal from the network entity and transmitting the sidelink reference signal to the respective sidelink UE; and process the Rx-Tx time difference associated with each sidelink UE based on the Rx-Tx time difference associated with each sidelink UE and a time difference measured by each sidelink UE to generate differential range sums of the plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving the sidelink reference signal from the first UE and receiving a second reference signal from the network entity, each differential range sum is a difference between a range sum from a reference sidelink UE of the plurality of sidelink UEs and a range sum from another sidelink UE of the plurality of sidelink UEs, and wherein the range sum of each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE, wherein the position of the first UE is determined based at least in part on the differential range sums of the plurality of sidelink UEs.

[0306] Clause 65. The non-transitory storage medium of clause 64, further comprising instructions to: receive a time difference measured by each of the plurality of sidelink UEs; wherein the instructions to process the Rx-Tx time difference associated with each sidelink UE to generate the differential range sum for the plurality of sidelink UEs comprise instructions to determine the differential range sum for the plurality of sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE.

[0307] Clause 66. The non-transitory storage medium of clause 65, wherein the instructions to determine the differential range sum comprise instructions to: determine a range sum for each sidelink UE based on the Rx-Tx time difference associated with the respective sidelink UE and the time difference measured by the respective sidelink UE; and determine a difference between the range sum for the reference sidelink UE and the range sum for each other sidelink UE from the plurality of sidelink UEs.

[0308] Clause 67. The non-transitory storage medium of any of clauses 65 or 66, wherein the time difference measured by each sidelink UE is received directly from each sidelink UE.

[0309] Clause 68. The non-transitory storage medium of any of clauses 65 or 66, wherein the time difference measured by each sidelink UE is received from a location server.

[0310] Clause 69. The non-transitory storage medium of any of clauses 65 or 66, further comprising instructions to receive, with the time difference measured by the respective sidelink UE, an identifier of a network entity, an identifier of a second reference signal received from the network entity, an identifier of a sidelink reference signal received from the first UE, and an identifier of the sidelink UE.

[0311] Clause 70. The first UE of clause 69, further comprising instructions to receive a timestamp having the time difference measured by the respective sidelink UE.

[0312] Clause 71. The non-transitory storage medium of any of clauses 65-70, further comprising instructions to receive, from a location server, an identifier of the reference sidelink UE.

[0313] Clause 72. The non-transitory storage medium of any of clauses 65-71, further comprising instructions to determine to use the differential range sum to determine the position of the first UE based at least in part on a group delay calibration status of the first UE.

[0314] Clause 73. The non-transitory storage medium of any of clauses 65-72, further comprising instructions to determine the position of the first UE based at least in part on the differential range sum for the plurality of sidelink UEs.

[0315] Clause 74. The non-transitory storage medium of clause 73, further comprising instructions to receive assistance data comprising a location of the network entity and a location of the sidelink UE, wherein the instructions to determine the location of the first UE use the location of the network entity and the location of the sidelink UE.

[0316] Clause 75. The non-transitory storage medium of any of clauses 65 or 66, further comprising instructions to send, to a location server, a differential range sum of the plurality of sidelink UEs, wherein the location of the first UE is determined by the location server based at least in part on the differential range sum of the plurality of sidelink UEs.

[0317] Clause 76. The non-transitory storage medium of clause 75, further comprising instructions to send, to the location server, the differential range sum of the plurality of sidelink UEs with an identifier of the network entity, an identifier of the first reference signal received from the network entity, an identifier of the one or more sidelink reference signals transmitted to the plurality of sidelink UEs, an identifier of the first UE, and an identifier of each sidelink UE.

[0318] Clause 77. The non-transitory storage medium of clause 76, further comprising instructions to send a timestamp with the differential range sum of the plurality of sidelink UEs.

[0319] Clause 78. The non-transitory storage medium of clause 64, wherein the instructions to process the Rx-Tx time difference associated with each sidelink UE to generate a differential range sum of the plurality of sidelink UEs comprise instructions to send the Rx-Tx time difference associated with each sidelink UE to a location server, wherein the differential range sum of the plurality of sidelink UEs is determined by the location server based on the Rx-Tx time difference associated with each sidelink UE and a time difference measured by each sidelink UE, and wherein the location of the first UE is determined by the location server based at least in part on the differential range sum of the plurality of sidelink UEs.

[0320] Clause 79. The non-transitory storage medium of clause 78, further comprising instructions to send the Rx-Tx time difference associated with each sidelink UE to the location server with an identifier of the network entity, an identifier of the first reference signal received from the network entity, an identifier of the one or more sidelink reference signals transmitted to the plurality of sidelink UEs, an identifier of the first UE, and an identifier of each sidelink UE.

[0321] Clause 80. The non-transitory storage medium of clause 79, further comprising instructions to send a timestamp with the Rx-Tx time difference associated with each sidelink UE.

[0322] Clause 81. The non-transitory storage medium of clause 78, further comprising instructions to send, to a location server, a group delay calibration status of the first UE, wherein the location of the first UE is determined based at least in part on the group delay calibration status of the first UE using the differential range sums of the plurality of sidelink UEs.

[0323] Clause 82. The non-transitory storage medium of clause 81, wherein the group delay calibration status of the first UE comprises an indication of whether a group delay of the first UE is calibrated.

[0324] Clause 83. The non-transitory storage medium of clause 81, wherein the group delay calibration status of the first UE comprises calibration error statistics of a group delay of the first UE.

[0325] Clause 84. The non-transitory storage medium of clause 83, wherein the group delay calibration status of the first UE is sent to the location server periodically, aperiodically, triggered by an event, or a combination thereof.

[0326] Clause 85. A method performed by a location server for determining a location of a first user equipment (UE), the method comprising: obtaining differential range sums of the first UE and a plurality of sidelink UEs based on a receive-transmit (Rx-Tx) time difference associated with each sidelink UE measured by the first UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference measured by the first UE between receiving a first reference signal from a network entity and transmitting a sidelink reference signal to the respective sidelink UE, wherein the differential range sums of the first UE and the plurality of sidelink UEs are further based on time differences measured by the plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving a sidelink reference signal from the first UE and receiving a second reference signal from the network entity, wherein each differential range sum is a difference between a range sum of a reference sidelink UE from the plurality of sidelink UEs and a range sum of another sidelink UE from the plurality of sidelink UEs, and wherein the range sum of each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE; and determining the location of the first UE based at least in part on the differential range sums of the plurality of sidelink UEs.

[0327] Clause 86. The method of clause 85, wherein determining the location of the first UE is further based on a location of the network entity and a location of the sidelink UE.

[0328] Clause 87. The method of any of clauses 85 or 86, wherein obtaining the differential range sum for the first UE and the plurality of sidelink UEs comprises: receiving, from the first UE, a Rx-Tx time difference associated with each sidelink UE; receiving a time difference measured by each sidelink UE; and determining the differential range sum for the first UE and the plurality of sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE.

[0329] Clause 88. The method of clause 87, wherein determining the differential range sum comprises: determining a range sum for each sidelink UE based on the Rx-Tx time difference associated with the respective sidelink UE and the time difference measured by the respective sidelink UE; and determining a difference between the range sum for the reference sidelink UE and the range sum for each other sidelink UE from the plurality of sidelink UEs.

[0330] Clause 89. The method of clause 87, further comprising receiving, from the first UE with the Rx-Tx time difference associated with each sidelink UE, an identifier of a network entity, an identifier of a first reference signal received from the network entity, an identifier of one or more sidelink reference signals transmitted to the plurality of sidelink UEs, an identifier of the first UE, and an identifier of each sidelink UE.

[0331] Clause 90. The method of clause 89, further comprising receiving a timestamp having the Rx-Tx time difference associated with each sidelink UE.

[0332] Clause 91. The method of clause 87, further comprising receiving, from each sidelink UE with the time difference measured by the respective sidelink UE, an identifier of a network entity, an identifier of a second reference signal received from the network entity, an identifier of a sidelink reference signal received from the first UE, and an identifier of the sidelink UE.

[0333] Clause 92. The method of clause 91, further comprising receiving, from each sidelink UE, a timestamp having the time difference measured by the respective sidelink UE.

[0334] Clause 93. The method of any of clauses 85 or 86, wherein obtaining the differential range sum for the first UE and the plurality of sidelink UEs comprises receiving, from the first UE, the differential range sum.

[0335] Clause 94. The method of clause 93, further comprising receiving, from the first UE with the differential range sum, an identifier of a network entity, an identifier of a first reference signal received from the network entity, an identifier of one or more sidelink reference signals transmitted to the plurality of sidelink UEs, an identifier of the first UE, and an identifier of each sidelink UE.

[0336] Clause 95. The method of clause 94, further comprising receiving, from the first UE, the time stamp with the differential range and.

[0337] Clause 96. The method of clause 93, further comprising: receiving, from each sidelink UE, an indication of a signal strength of a signal from the first UE measured by each respective sidelink UE; determining the reference sidelink UE based at least in part on the indication of the signal strength of the signal from the first UE measured by each respective sidelink UE; and transmitting, to the first UE, an identifier of the reference sidelink UE.

[0338] Clause 97. The method of any of clauses 85 or 86, further comprising: receiving, from the first UE, a group delay calibration status of the first UE; and determining to use the differential range sums of the plurality of sidelink UEs to determine the position of the first UE based at least in part on the group delay calibration status of the first UE.

[0339] Clause 98. The method of clause 97, wherein the group delay calibration status of the first UE comprises an indication of whether a group delay of the first UE is calibrated.

[0340] Clause 99. The method of clause 97, wherein the group delay calibration status of the first UE comprises calibration error statistics of a group delay of the first UE.

[0341] Clause 100. The method of clause 99, wherein the group delay calibration status of the first UE is received from the first UE periodically, aperiodically, triggered by an event, or a combination thereof.

[0342] Clause 101. A location server configured for determining a location of a first user equipment (UE), the location server comprising: an external interface configured for communication with other entities in a wireless network; at least one memory; and at least one processor coupled to the external interface and the at least one memory and configured to: obtain, via the external interface, differential range sums for the first UE and a plurality of sidelink UEs based on a receive-transmit (Rx-Tx) time difference associated with each sidelink UE measured by the first UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference measured by the first UE between receiving a first reference signal from a network entity and transmitting a sidelink reference signal to the respective sidelink UE, wherein the differential range sums for the first UE and the plurality of sidelink UEs are further based on time differences measured by the plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving a sidelink reference signal from the first UE and receiving a second reference signal from the network entity, wherein each differential range sum is a difference between a range sum for a reference sidelink UE from the plurality of sidelink UEs and a range sum for another sidelink UE from the plurality of sidelink UEs, and wherein the range sum for each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE; and determine the location of the first UE based at least in part on the differential range sums for the plurality of sidelink UEs.

[0343] Clause 102. The location server of clause 101, wherein the at least one processor is configured to determine the location of the first UE further based on a location of the network entity and a location of the sidelink UEs.

[0344] Clause 103. The location server of any of clauses 101 or 102, wherein the at least one processor is configured to obtain the differential range sums for the first UE and the plurality of sidelink UEs by being configured to: receive, via the external interface, the Rx-Tx time difference associated with each sidelink UE from the first UE; receive, via the external interface, the time difference measured by each sidelink UE; and determine the differential range sums for the first UE and the plurality of sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE.

[0345] Clause 104. The location server of clause 103, wherein the at least one processor is configured to determine the differential range sums by being configured to: determine a range sum for each sidelink UE based on the Rx-Tx time difference associated with the respective sidelink UE and the time difference measured by the respective sidelink UE; and determine a difference between the range sum for the reference sidelink UE and the range sum for each other sidelink UE from the plurality of sidelink UEs.

[0346] Clause 105. The location server of clause 103, wherein the at least one processor is further configured to receive, from the first UE with the Rx-Tx time difference associated with each sidelink UE, an identifier of the network entity, an identifier of the first reference signal received from the network entity, an identifier of the one or more sidelink reference signals transmitted to the plurality of sidelink UEs, an identifier of the first UE, and an identifier of each sidelink UE.

[0347] Clause 106. The location server of clause 105, wherein the at least one processor is further configured to receive, via the external interface, a timestamp with the Rx-Tx time difference associated with each sidelink UE.

[0348] Clause 107. The location server of clause 103, wherein the at least one processor is further configured to receive, from each sidelink UE via the external interface with the time difference measured by the respective sidelink UE, an identifier of the network entity, an identifier of the second reference signal received from the network entity, an identifier of the sidelink reference signal received from the first UE, and an identifier of the sidelink UE.

[0349] Clause 108. The location server of clause 107, wherein the at least one processor is further configured to receive, from each sidelink UE via the external interface, a timestamp with the time difference measured by the respective sidelink UE.

[0350] Clause 109. The location server of any of clauses 101 or 102, wherein the at least one processor is configured to obtain the differential range sums of the first UE and the plurality of sidelink UEs by being configured to receive, from the first UE via the external interface, the differential range sums.

[0351] Clause 110. The location server of clause 109, wherein the at least one processor is further configured to receive, from the first UE with the differential range sums, an identifier of the network entity, an identifier of the first reference signal received from the network entity, an identifier of the one or more sidelink reference signals transmitted to the plurality of sidelink UEs, an identifier of the first UE, and an identifier of each sidelink UE.

[0352] Clause 111. The location server of clause 110, wherein the at least one processor is further configured to receive, from the first UE via the external interface, a timestamp with the differential range sums.

[0353] Clause 112. The location server of clause 109, wherein the at least one processor is further configured to: receive, via the external interface from each sidelink UE, an indication of a signal strength of a signal from the first UE measured by each respective sidelink UE; determine the reference sidelink UE based at least in part on the indication of the signal strength of the signal from the first UE measured by each respective sidelink UE; and transmit, via the external interface to the first UE, an identifier of the reference sidelink UE.

[0354] Clause 113. The location server of any of clauses 101 or 102, wherein the at least one processor is further configured to: receive, via the external interface from the first UE, a group delay calibration status of the first UE; and determine to use differential range and of the plurality of sidelink UEs to determine the location of the first UE based at least in part on the group delay calibration status of the first UE.

[0355] Clause 114. The location server of clause 113, wherein the group delay calibration status of the first UE comprises an indication of whether a group delay of the first UE is calibrated.

[0356] Clause 115. The location server of clause 113, wherein the group delay calibration status of the first UE comprises calibration error statistics of a group delay of the first UE.

[0357] Clause 116. The location server of clause 115, wherein the group delay calibration status of the first UE is received from the first UE periodically, aperiodically, triggered by an event, or a combination thereof.

[0358] Clause 117. A location server configured for determining a location of a first user equipment (UE), the location server comprising: means for obtaining differential range sums for the first UE and a plurality of sidelink UEs based on a receive-transmit (Rx-Tx) time difference associated with each sidelink UE measured by the first UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference measured by the first UE between receiving a first reference signal from a network entity and transmitting a sidelink reference signal to the respective sidelink UE, wherein the differential range sums for the first UE and the plurality of sidelink UEs are further based on time differences measured by the plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving a sidelink reference signal from the first UE and receiving a second reference signal from the network entity, wherein each differential range sum is a difference between a range sum for a reference sidelink UE from the plurality of sidelink UEs and a range sum for another sidelink UE from the plurality of sidelink UEs, and wherein the range sum for each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE; and means for determining the location of the first UE based at least in part on the differential range sums for the plurality of sidelink UEs.

[0359] Clause 118. The location server of clause 117, wherein the means for determining the location of the first UE is further based on a location of the network entity and a location of the sidelink UEs.

[0360] Clause 119. The location server of any of clauses 117 or 118, wherein the means for obtaining the differential range sums for the first UE and the plurality of sidelink UEs comprises: means for receiving the Rx-Tx time difference associated with each sidelink UE from the first UE; means for receiving the time difference measured by each sidelink UE; and means for determining the differential range sums for the first UE and the plurality of sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE.

[0361] Clause 120. The location server of clause 119, wherein the means for determining the differential range sums comprises: means for determining a range sum for each sidelink UE based on the Rx-Tx time difference associated with the respective sidelink UE and the time difference measured by the respective sidelink UE; and means for determining a difference between the range sum for a reference sidelink UE and the range sum for each other sidelink UE from the plurality of sidelink UEs.

[0362] Clause 121. The location server of clause 119, further comprising means for receiving, from the first UE with the Rx-Tx time difference associated with each sidelink UE, an identifier of the network entity, an identifier of the first reference signal received from the network entity, an identifier of the one or more sidelink reference signals transmitted to the plurality of sidelink UEs, an identifier of the first UE, and an identifier of each sidelink UE.

[0363] Clause 122. The location server of clause 121, further comprising means for receiving a timestamp with the Rx-Tx time difference associated with each sidelink UE.

[0364] Clause 123. The location server of clause 119, further comprising means for receiving, from each sidelink UE with the time difference measured by the respective sidelink UE, an identifier of the network entity, an identifier of the second reference signal received from the network entity, an identifier of the sidelink reference signal received from the first UE, and an identifier of the sidelink UE.

[0365] Clause 124. The location server of clause 123, further comprising means for receiving, from each sidelink UE, a timestamp with the time difference measured by the respective sidelink UE.

[0366] Clause 125. The location server of any of clauses 117 or 118, wherein the means for obtaining the differential range-sums of the first UE and the plurality of sidelink UEs receives the differential range-sums from the first UE.

[0367] Clause 126. The location server of clause 125, further comprising means for receiving, from the first UE with the differential range-sums, an identifier of the network entity, an identifier of the first reference signal received from the network entity, an identifier of the one or more sidelink reference signals transmitted to the plurality of sidelink UEs, an identifier of the first UE, and an identifier of each sidelink UE.

[0368] Clause 127. The location server of clause 126, further comprising means for receiving, from the first UE, a timestamp with the differential range-sums.

[0369] Clause 128. The location server of clause 125, further comprising: means for receiving, from each sidelink UE, an indication of a signal strength of a signal from the first UE measured by each respective sidelink UE; means for determining a reference sidelink UE based at least in part on the indication of the signal strength of the signal from the first UE measured by each respective sidelink UE; and means for transmitting, to the first UE, an identifier of the reference sidelink UE.

[0370] Clause 129. The location server of any of clauses 117 or 118, further comprising: means for receiving, from the first UE, a group delay calibration status of the first UE; and means for determining to use the differential range sums of the plurality of sidelink UEs to determine the location of the first UE based at least in part on the group delay calibration status of the first UE.

[0371] Clause 130. The location server of clause 129, wherein the group delay calibration status of the first UE comprises an indication of whether a group delay of the first UE is calibrated.

[0372] Clause 131. The location server of clause 129, wherein the group delay calibration status of the first UE comprises calibration error statistics of a group delay of the first UE.

[0373] Clause 132. The location server of clause 131, wherein the group delay calibration status of the first UE is received from the first UE periodically, aperiodically, triggered by an event, or a combination thereof.

[0374] Clause 133. A non-transitory storage medium including program code stored thereon, the program code is operable to configure at least one processor in a location server for determining a location of a first user equipment (UE), the program code comprising instructions to: obtain differential range sums of the first UE and a plurality of sidelink UEs based on a receive-transmit (Rx-Tx) time difference associated with each sidelink UE measured by the first UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference measured by the first UE between receiving a first reference signal from a network entity and transmitting a sidelink reference signal to the respective sidelink UE, wherein the differential range sums of the first UE and the plurality of sidelink UEs are further based on time differences measured by the plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving a sidelink reference signal from the first UE and receiving a second reference signal from the network entity, wherein each differential range sum is a difference between a range sum of a reference sidelink UE from the plurality of sidelink UEs and a range sum of another sidelink UE from the plurality of sidelink UEs, and wherein the range sum of each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE; and determine the location of the first UE based at least in part on the differential range sums of the plurality of sidelink UEs.

[0375] Clause 134. The non-transitory storage medium of clause 133, wherein the instructions to determine the location of the first UE are further based on a location of the network entity and a location of the sidelink UE.

[0376] Clause 135. A non-transitory storage medium pursuant to any of Clauses 133 or 134, wherein the instructions for obtaining the differential distance sum of a first UE and a plurality of sidelink UEs include instructions to: receive from the first UE an Rx-Tx time difference associated with each sidelink UE; receive a time difference measured by each sidelink UE; and determine the differential distance sum of the first UE and the plurality of sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE.

[0377] Clause 136. The non-transitory storage medium pursuant to Clause 135, wherein the instructions for determining the differential distance sum include instructions to: determine the distance sum for each sidelink UE based on the Rx-Tx time difference associated with the respective sidelink UE and the time difference measured by the respective sidelink UE; and determine the difference between the distance sum of a reference sidelink UE and the distance sum of each other sidelink UE from a plurality of sidelink UEs.

[0378] Clause 137. The non-transitory storage medium pursuant to Clause 135 also includes instructions for receiving, together with the Rx-Tx time difference associated with each sidelink UE, an identifier of a network entity, an identifier of a first reference signal received from the network entity, an identifier of one or more sidelink reference signals sent to the plurality of sidelink UEs, an identifier of the first UE, and an identifier of each sidelink UE.

[0379] Clause 138. The non-transitory storage medium pursuant to Clause 137 also includes instructions for receiving a timestamp having an Rx-Tx time difference associated with each sidelink UE.

[0380] Clause 139. The non-transitory storage medium pursuant to Clause 135 also includes instructions for receiving, together with the time difference measured by the respective sidelink UE, an identifier of a network entity, an identifier of a second reference signal received from the network entity, an identifier of a sidelink reference signal received from the first UE, and an identifier of the sidelink UE.

[0381] Clause 140. The first UE pursuant to Clause 139 also includes instructions for receiving from each sidelink UE a timestamp having a time difference measured by the respective sidelink UE.

[0382] Clause 141. A non-transitory storage medium pursuant to any of Clauses 133 or 134, wherein the instructions for obtaining the differential distance sum of the first UE and a plurality of side-link UEs include instructions for receiving the differential distance sum from the first UE.

[0383] Clause 142. The non-transitory storage medium of clause 141, further comprising instructions for receiving, from the first UE with the differential range and, an identifier of the network entity, an identifier of the first reference signal received from the network entity, an identifier of the one or more sidelink reference signals transmitted to the plurality of sidelink UEs, an identifier of the first UE, and an identifier of each sidelink UE.

[0384] Clause 143. The non-transitory storage medium of clause 142, further comprising instructions for receiving, from the first UE, a timestamp with the differential range and.

[0385] Clause 144. The non-transitory storage medium of clause 141, further comprising instructions to: receive, from each sidelink UE, an indication of a signal strength of a signal from the first UE measured by each respective sidelink UE; determine a reference sidelink UE based at least in part on the indication of the signal strength of the signal from the first UE measured by each respective sidelink UE; and transmit, to the first UE, an identifier of the reference sidelink UE.

[0386] Clause 145. The non-transitory storage medium of any of clauses 133 or 134, further comprising instructions to: receive, from the first UE, a group delay calibration status of the first UE; and determine to use the differential range and of the plurality of sidelink UEs to determine the position of the first UE based at least in part on the group delay calibration status of the first UE.

[0387] Clause 146. The non-transitory storage medium of clause 145, wherein the group delay calibration status of the first UE comprises an indication of whether a group delay of the first UE is calibrated.

[0388] Clause 147. The non-transitory storage medium of clause 145, wherein the group delay calibration status of the first UE comprises calibration error statistics of a group delay of the first UE.

[0389] Clause 148. The non-transitory storage medium of clause 147, wherein the group delay calibration status of the first UE is received from the first UE periodically, aperiodically, triggered by an event, or a combination thereof.

[0390] Clause 149. A method performed by a location server for determining a location of a first user equipment (UE), the method comprising: receiving time differences measured by a plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving a sidelink reference signal from the first UE and receiving a reference signal from a network entity; and transmitting, to the first UE, the time differences measured by the plurality of sidelink UEs to determine the location of the first UE based on the time differences measured by the plurality of sidelink UEs and a receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference measured by the first UE between receiving a second reference signal from the network entity and transmitting a sidelink reference signal to the respective sidelink UE.

[0391] Clause 150. The method of clause 149, further comprising transmitting, to the first UE, assistance data including at least a location of the network entity.

[0392] Clause 151. The method of clause 150, wherein the assistance data further includes a location of each sidelink UE.

[0393] Clause 152. The method of any of clauses 149-151, further comprising receiving, with the time differences measured by the plurality of sidelink UEs, an identifier of the network entity, an identifier of the second reference signal received from the network entity, an identifier of the sidelink reference signal received from the first UE, and an identifier of the sidelink UE.

[0394] Clause 153. The method of clause 152, further comprising receiving a timestamp with the time differences measured by the plurality of sidelink UEs.

[0395] Clause 154. The method of any of clauses 149-153, wherein the first UE determines a plurality of sidelink UE differential range sums based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE, wherein each differential range sum is a difference between a range sum from a reference sidelink UE of the plurality of sidelink UEs and a range sum from another sidelink UE of the plurality of sidelink UEs, and wherein the range sum for each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE.

[0396] Clause 155. The method of clause 154, further comprising: receiving, from each sidelink UE, an indication of a signal strength of a signal from the first UE measured by each respective sidelink UE; determining a reference sidelink UE based at least in part on the indication of the signal strength of the signal from the first UE measured by each respective sidelink UE; and transmitting, to the first UE, an identifier of the reference sidelink UE.

[0397] Clause 156. A location server configured for determining a location of a first user equipment (UE), the location server comprising: an external interface configured to communicate with other entities in a wireless network; at least one memory; and at least one processor coupled to the external interface and the at least one memory and configured to: receive, via the external interface, time differences measured by a plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between a reception of a sidelink reference signal from the first UE and a reception of a reference signal from a network entity; and send, via the external interface to the first UE, the time differences measured by the plurality of sidelink UEs to determine the location of the first UE based on the time differences measured by the plurality of sidelink UEs and a receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference measured by the first UE between a reception of a second reference signal from the network entity and a transmission of a sidelink reference signal to the respective sidelink UE.

[0398] Clause 157. The location server of clause 156, wherein the at least one processor is further configured to send, via the external interface to the first UE, assistance data comprising at least a location of the network entity.

[0399] Clause 158. The location server of clause 157, wherein the assistance data further comprises a location of each sidelink UE.

[0400] Clause 159. The location server of any of clauses 156-158, wherein the at least one processor is further configured to receive, with the time differences measured by the plurality of sidelink UEs, an identifier of the network entity, an identifier of the second reference signal received from the network entity, an identifier of the sidelink reference signal received from the first UE, and an identifier of the sidelink UE.

[0401] Clause 160. The location server of clause 159, wherein the at least one processor is further configured to receive, via the external interface, a timestamp with the time differences measured by the plurality of sidelink UEs.

[0402] Clause 161. The location server of any of clauses 156-160, wherein the first UE determines a plurality of sidelink UE differential range sums based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE, wherein each differential range sum is a difference between a range sum from a reference sidelink UE of the plurality of sidelink UEs and a range sum from another sidelink UE of the plurality of sidelink UEs, and wherein the range sum for each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE.

[0403] Clause 162. The location server of clause 161, wherein the at least one processor is further configured to: receive, via the external interface from each sidelink UE, an indication of a signal strength of a signal from the first UE measured by each respective sidelink UE; determine a reference sidelink UE based at least in part on the indication of the signal strength of the signal from the first UE measured by each respective sidelink UE; and transmit, via the external interface to the first UE, an identifier of the reference sidelink UE.

[0404] Clause 163. A location server configured for determining a location of a first user equipment (UE), the location server comprising: means for receiving a time difference measured by a plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving a sidelink reference signal from the first UE and receiving a reference signal from a network entity; and means for transmitting the time difference measured by the plurality of sidelink UEs to the first UE to determine the location of the first UE based on the time difference measured by the plurality of sidelink UEs and a receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference measured by the first UE between receiving a second reference signal from the network entity and transmitting a sidelink reference signal to the respective sidelink UE.

[0405] Clause 164. The location server of clause 163, further comprising means for transmitting assistance data comprising at least a location of the network entity to the first UE.

[0406] Clause 165. The location server of clause 164, wherein the assistance data further comprises a location of each sidelink UE.

[0407] Clause 166. The location server of any of clauses 163-165, further comprising means for receiving, with the time difference measured by the plurality of sidelink UEs, an identifier of the network entity, an identifier of the second reference signal received from the network entity, an identifier of the sidelink reference signal received from the first UE, and an identifier of the sidelink UE.

[0408] Clause 167. The location server of clause 166, further comprising means for receiving a timestamp with the time difference measured by the plurality of sidelink UEs.

[0409] Clause 168. The location server of any of clauses 163-167, wherein the first UE determines differential ranges and for the plurality of sidelink UEs based on a Rx-Tx time difference associated with each sidelink UE and a time difference measured by each sidelink UE, wherein each differential range and is a difference between a range sum from a reference sidelink UE of the plurality of sidelink UEs and a range sum from another sidelink UE of the plurality of sidelink UEs, and wherein the range sum for each sidelink UE is a sum of a first distance between the first UE and the network entity and a second distance between the first UE and the respective sidelink UE.

[0410] Clause 169. The location server of clause 168, further comprising: means for receiving, from each sidelink UE, an indication of a signal strength of a signal from the first UE measured by each respective sidelink UE; means for determining the reference sidelink UE based at least in part on the indication of the signal strength of the signal from the first UE measured by each respective sidelink UE; and means for transmitting, to the first UE, an identifier of the reference sidelink UE.

[0411] Clause 170. A non-transitory storage medium including program code stored thereon, the program code is operable to configure at least one processor in a location server for determining a location of a first user equipment (UE), the program code comprising instructions to: receive a time difference measured by a plurality of sidelink UEs, wherein the time difference measured by each sidelink UE is a time difference between receiving a sidelink reference signal from the first UE and receiving a reference signal from a network entity; and transmit, to the first UE, the time difference measured by the plurality of sidelink UEs to determine the location of the first UE based on the time difference measured by the plurality of sidelink UEs and a receive-transmit (Rx-Tx) time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is a time difference m...

Claims

1. A method for determining the location of a first user equipment (UE) performed by a first UE, the method comprising: Receive the first reference signal from the network entity; Send one or more sidelink reference signals to multiple sidelink UEs; Determine the receive-transmit Rx-Tx time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is the time difference between the network entity receiving the first reference signal and transmitting the sidelink reference signal to the corresponding sidelink UE; as well as The Rx-Tx time difference associated with each sidelink UE is processed to generate a differential distance sum for the plurality of sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE, wherein the time difference measured by each sidelink UE is the time difference between the first UE receiving the sidelink reference signal and the network entity receiving the second reference signal, each differential distance sum is the difference between the distance sum of a reference sidelink UE from the plurality of sidelink UEs and the distance sum of another sidelink UE from the plurality of sidelink UEs, and wherein the distance sum of each sidelink UE is the sum of a first distance between the first UE and the network entity and a second distance between the first UE and the corresponding sidelink UE, wherein the position of the first UE is determined at least in part based on the differential distance sum of the plurality of sidelink UEs.

2. The method according to claim 1, further comprising: Receive the time difference measured by each of the plurality of sidelink UEs; The processing of the Rx-Tx time difference associated with each sidelink UE to generate the differential distance of the plurality of sidelink UEs includes determining the differential distance of the plurality of sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE.

3. The method of claim 2, wherein determining the differential distance comprises: The distance is determined for each sidelink UE based on the Rx-Tx time difference associated with the corresponding sidelink UE and the time difference measured by the corresponding sidelink UE; as well as Determine the difference between the distance sum of the reference sidelink UE and the distance sum of each of the plurality of sidelink UEs.

4. The method of claim 2, wherein the time difference measured by each sidelink UE is received directly from each sidelink UE.

5. The method of claim 2, wherein the time difference measured by each sidelink UE is received from the location server.

6. The method of claim 2, further comprising receiving, together with the time difference measured by the respective sidelink UE, an identifier of the network entity, an identifier of the second reference signal received from the network entity, an identifier of the sidelink reference signal received from the first UE, and an identifier of the sidelink UE.

7. The method of claim 2, further comprising receiving an identifier of the reference sidelink UE from a location server.

8. The method of claim 2, further comprising determining the location of the first UE using the differential distance, based at least in part on the group delay calibration state of the first UE.

9. The method of claim 2, further comprising determining the location of the first UE based at least in part on the differential distances of the plurality of side-link UEs.

10. The method of claim 2, further comprising sending the differential distance sum of the plurality of sidelink UEs to a location server, wherein the location of the first UE is determined by the location server at least in part based on the differential distance sum of the plurality of sidelink UEs.

11. The method of claim 1, wherein processing the Rx-Tx time difference associated with each sidelink UE to generate the differential distance of the plurality of sidelink UEs includes sending the Rx-Tx time difference associated with each sidelink UE to a location server, wherein the differential distance of the plurality of sidelink UEs is determined by the location server based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE, and wherein the location of the first UE is determined by the location server at least in part based on the differential distance of the plurality of sidelink UEs.

12. The method of claim 11, further comprising sending the Rx-Tx time difference associated with each sidelink UE, together with the identifier of the network entity, the identifier of the first reference signal received from the network entity, the identifier of the one or more sidelink reference signals sent to the plurality of sidelink UEs, the identifier of the first UE, and the identifier of each of the sidelink UEs, to the location server.

13. The method of claim 11, further comprising sending the group delay calibration status of the first UE to the location server, wherein the location server determines the location of the first UE by using the differential distances of the plurality of sidelink UEs at least in part based on the group delay calibration status of the first UE.

14. A first user equipment (UE), configured to determine the location of the first UE, the first UE comprising: At least one wireless transceiver is configured to communicate wirelessly with other entities in a wireless network; At least one memory; and At least one processor, coupled to the at least one wireless transceiver and the at least one memory, and configured to: Receive a first reference signal from a network entity via the at least one wireless transceiver; One or more sidelink reference signals are transmitted to multiple sidelink UEs via the at least one wireless transceiver; Determine the receive-transmit Rx-Tx time difference associated with each sidelink UE, wherein the Rx-Tx time difference associated with each sidelink UE is the time difference between the network entity receiving the first reference signal and transmitting the sidelink reference signal to the corresponding sidelink UE; as well as The Rx-Tx time difference associated with each sidelink UE is processed to generate a differential distance sum for the plurality of sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE, wherein the time difference measured by each sidelink UE is the time difference between the first UE receiving the sidelink reference signal and the network entity receiving the second reference signal, each differential distance sum is the difference between the distance sum of a reference sidelink UE from the plurality of sidelink UEs and the distance sum of another sidelink UE from the plurality of sidelink UEs, and wherein the distance sum of each sidelink UE is the sum of a first distance between the first UE and the network entity and a second distance between the first UE and the corresponding sidelink UE, wherein the position of the first UE is determined at least in part based on the differential distance sum of the plurality of sidelink UEs.

15. The first UE according to claim 14, wherein, The at least one processor is further configured to: The time difference measured by each of the plurality of sidelink UEs is received via the at least one wireless transceiver; The at least one processor is configured to process the Rx-Tx time difference associated with each sidelink UE to generate the differential distance sum of the plurality of sidelink UEs by being configured to determine the differential distance sum of the plurality of sidelink UEs based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE.

16. The first UE according to claim 15, wherein, The at least one processor is configured to determine the differential distance sum by being configured to perform the following operations: The distance is determined for each sidelink UE based on the Rx-Tx time difference associated with the corresponding sidelink UE and the time difference measured by the corresponding sidelink UE; as well as Determine the difference between the distance sum of the reference sidelink UE and the distance sum of each of the plurality of sidelink UEs.

17. The first UE of claim 15, wherein the time difference measured by each sidelink UE is received directly from each sidelink UE.

18. The first UE of claim 15, wherein the time difference measured by each sidelink UE is received from the location server.

19. The first UE according to claim 15, wherein, The at least one processor is further configured to receive, together with the time difference measured by the respective sidelink UE, the identifier of the network entity, the identifier of the second reference signal received from the network entity, the identifier of the sidelink reference signal received from the first UE, and the identifier of the sidelink UE.

20. The first UE according to claim 15, wherein, The at least one processor is also configured to receive the identifier of the reference sidelink UE from the location server via the at least one wireless transceiver.

21. The first UE according to claim 15, wherein, The at least one processor is also configured to determine the location of the first UE using the differential distance, at least in part, based on the group delay calibration state of the first UE.

22. The first UE according to claim 15, wherein, The at least one processor is also configured to determine the location of the first UE based at least in part on the differential distances of the plurality of side-link UEs.

23. The first UE according to claim 15, wherein, The at least one processor is further configured to transmit the differential distance sum of the plurality of sidelink UEs to a location server via the at least one wireless transceiver, wherein the location of the first UE is determined by the location server based at least in part on the differential distance sum of the plurality of sidelink UEs.

24. The first UE according to claim 14, wherein, The at least one processor is configured to process the Rx-Tx time difference associated with each sidelink UE by being configured to send the Rx-Tx time difference associated with each sidelink UE to a location server to generate the differential distance sum of the plurality of sidelink UEs, wherein the differential distance sum of the plurality of sidelink UEs is determined by the location server based on the Rx-Tx time difference associated with each sidelink UE and the time difference measured by each sidelink UE, and wherein the location of the first UE is determined by the location server at least in part based on the differential distance sum of the plurality of sidelink UEs.

25. The first UE according to claim 24, wherein, The at least one processor is further configured to send the Rx-Tx time difference associated with each sidelink UE, together with the identifier of the network entity, the identifier of the first reference signal received from the network entity, the identifier of the one or more sidelink reference signals sent to the plurality of sidelink UEs, the identifier of the first UE, and the identifier of each sidelink UE, to the location server.

26. The first UE according to claim 24, wherein, The at least one processor is further configured to send the group delay calibration status of the first UE to the location server via the at least one wireless transceiver, wherein the location server determines the location of the first UE by using the differential distance of the plurality of sidelink UEs at least in part based on the group delay calibration status of the first UE.

27. A method for determining the location of a second UE, performed by a first user equipment (UE), wherein the first UE and the second UE communicate via a sidelink, the method comprising: Receive the first reference signal from the network entity; Receive side link reference signal from the second UE; as well as Determine the time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity; as well as The time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity is processed to generate a differential distance sum between the second UE and a plurality of sidelink UEs including the first UE based on the receive-transmit Rx-Tx time difference associated with each sidelink UE measured by the second UE, wherein the Rx-Tx time difference associated with each sidelink UE is the time difference between receiving the second reference signal from the network entity and transmitting the sidelink reference signal to the corresponding sidelink UE measured by the second UE, wherein the differential distance sum between the second UE and the plurality of sidelink UEs is also based on the time difference measured by the plurality of sidelink UEs, wherein each differential distance sum is the difference between the distance sum of a reference sidelink UE from the plurality of sidelink UEs and the distance sum of another sidelink UE from the plurality of sidelink UEs, and wherein the distance sum of each sidelink UE is the sum of a first distance between the second UE and the network entity and a second distance between the second UE and the corresponding sidelink UE, and wherein the position of the second UE is determined at least in part based on the differential distance sum of the plurality of sidelink UEs.

28. The method according to claim 27, wherein, Processing the time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity to generate the differential distance includes sending the time difference to a location server.

29. The method of claim 28, wherein the differential distance sum is determined by the location server, and the location of the second UE is determined by the location server based on the differential distance sum.

30. The method according to claim 28, wherein, The location server sends the time difference to the second UE, and the second UE determines the differential distance sum, and determines the location of the second UE based on the differential distance sum.

31. The method according to claim 27, wherein, Processing the time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity to generate the differential distance includes sending the time difference to the second UE.

32. The method according to claim 31, wherein, The second UE determines the differential distance sum, and the location server determines the location of the second UE based on the differential distance sum.

33. The method according to claim 31, wherein, The second UE determines the differential distance sum and determines the position of the second UE based on the differential distance sum.

34. The method according to claim 27, wherein, Processing the time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity to generate the differential distance includes sending the time difference to the entity, and also includes sending, along with the time difference, an identifier of the network entity, an identifier of the first reference signal received from the network entity, an identifier of the sidelink reference signal received from the second UE, and an identifier of the first UE.

35. The method of claim 34, further comprising sending a timestamp having the time difference.

36. The method of claim 27, further comprising: Measure the signal strength of one or more signals received from the second UE; The signal strength indication of the one or more signals received from the second UE is transmitted for determining the reference sidelink UE based at least in part on the signal strength indication of the signals from the second UE measured by each sidelink UE including the first UE.

37. A first user equipment (UE) configured to determine the location of a second UE, the first UE communicating with the second UE via a sidelink, the first UE comprising: At least one wireless transceiver is configured to communicate wirelessly with other entities in a wireless network; At least one memory; and At least one processor, coupled to the at least one wireless transceiver and the at least one memory, and configured to: Receive a first reference signal from a network entity via the at least one wireless transceiver; Receive sidelink reference signal from the second UE via the at least one wireless transceiver; as well as Determine the time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity; as well as The time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity is processed to generate a differential distance sum between the second UE and a plurality of sidelink UEs including the first UE based on the receive-transmit Rx-Tx time difference associated with each sidelink UE measured by the second UE, wherein the Rx-Tx time difference associated with each sidelink UE is the time difference between receiving the second reference signal from the network entity and transmitting the sidelink reference signal to the corresponding sidelink UE measured by the second UE, wherein the differential distance sum between the second UE and the plurality of sidelink UEs is also based on the time difference measured by the plurality of sidelink UEs, wherein each differential distance sum is the difference between the distance sum of a reference sidelink UE from the plurality of sidelink UEs and the distance sum of another sidelink UE from the plurality of sidelink UEs, and wherein the distance sum of each sidelink UE is the sum of a first distance between the second UE and the network entity and a second distance between the second UE and the corresponding sidelink UE, and wherein the position of the second UE is determined at least in part based on the differential distance sum of the plurality of sidelink UEs.

38. The first UE according to claim 37, wherein, The at least one processor is configured to process the time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity by being configured to send the time difference to the location server via the at least one radio transceiver to generate the differential distance.

39. The first UE according to claim 38, wherein the differential distance sum is determined by the location server, and the location of the second UE is determined by the location server based on the differential distance sum.

40. The first UE according to claim 38, wherein, The location server sends the time difference to the second UE, and the second UE determines the differential distance sum, and determines the location of the second UE based on the differential distance sum.

41. The first UE according to claim 37, wherein, The at least one processor is configured to process the time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity by being configured to transmit the time difference to the second UE via the at least one radio transceiver to generate the differential distance.

42. The first UE according to claim 41, wherein, The second UE determines the differential distance sum, and the location server determines the location of the second UE based on the differential distance sum.

43. The first UE according to claim 41, wherein, The second UE determines the differential distance sum and determines the position of the second UE based on the differential distance sum.

44. The first UE according to claim 37, wherein, The at least one processor is configured to process the time difference between receiving the sidelink reference signal from the second UE and receiving the first reference signal from the network entity by being configured to transmit the time difference to the entity via the at least one radio transceiver to generate the differential distance sum, wherein the at least one processor is further configured to transmit, along with the time difference, an identifier of the network entity, an identifier of the first reference signal received from the network entity, an identifier of the sidelink reference signal received from the second UE, and an identifier of the first UE.

45. The first UE according to claim 44, wherein, The at least one processor is also configured to transmit a timestamp having the time difference via the at least one wireless transceiver.

46. ​​The first UE according to claim 37, wherein, The at least one processor is further configured to: Measure the signal strength of one or more signals received from the second UE; The signal strength indication of one or more signals received from the second UE is transmitted via the at least one wireless transceiver, for determining the reference sidelink UE based at least in part on the indication of the signal strength of the signals from the second UE measured by each sidelink UE including the first UE.

47. An apparatus for determining the location of a first user equipment (UE), the apparatus comprising components for performing the method according to any one of claims 1 to 13.

48. A computer-readable medium having program code recorded thereon, wherein the program code is executable by one or more processors to cause the processors to perform the method according to any one of claims 1 to 13.

49. A computer program product comprising computer-readable instructions that, when executed by a processor, cause the processor to perform the method according to any one of claims 1 to 13.

50. An apparatus for determining the location of a second user equipment (UE), the apparatus comprising components for performing the method according to any one of claims 27 to 36.

51. A computer-readable medium having program code recorded thereon, wherein the program code is executable by one or more processors to cause the processors to perform the method according to any one of claims 27 to 36.

52. A computer program product comprising computer-readable instructions that, when executed by a processor, cause the processor to perform the method according to any one of claims 27 to 36.

Images