Base Station Assisted User Equipment-to-User Equipment Positioning

Abstract

Techniques for wireless positioning are disclosed. In one aspect, a first user equipment (UE) transmits a request to perform a UE-UE positioning procedure with a second UE; receives a radio resource configuration for the UE-UE positioning procedure, the radio resource configuration indicating a first radio resource for transmitting a positioning signal to the second UE and a second radio resource for receiving a positioning signal from the second UE; transmits one or more first positioning signals to the second UE on the first radio resource; receives one or more second positioning signals from the second UE on the second radio resource; and estimates a distance between the first UE and the second UE based at least on a transmission time of the one or more first positioning signals and an arrival time (ToA) of the one or more second positioning signals.

Description

[0001] Disclosed Background

[0002] Disclosed Field

[0003] Aspects described herein generally relate to wireless positioning.

[0004] Description of Related Art

[0005] Wireless communication systems have evolved through several generations, including first-generation analog wireless telephone service (1G), second-generation (2G) digital wireless telephone service (including transitional 2.5G networks), third-generation (3G) high-speed data wireless services with Internet capabilities, and fourth-generation (4G) services (e.g., LTE or WiMax). There are many different types of wireless communication systems in use currently, including cellular and personal communication service (PCS) systems. Examples of known cellular systems include the cellular analog Advanced Mobile Phone System (AMPS), and digital cellular systems based on Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Global System for Mobile Communications (GSM), etc.

[0006] The fifth-generation (5G) wireless standard (referred to as New Radio (NR)) enables higher data transfer speeds, a larger number of connections and better coverage, and other improvements. According to the Next Generation Mobile Networks Alliance, the NR standard is designed to provide data rates of tens of megabits per second to each of tens of thousands of users, and a data rate of 1 gigabit per second to dozens of employees in an office floor. Support should be provided for hundreds of thousands of simultaneous connections to support large-scale wireless sensor deployments. Thus, the spectral efficiency of NR mobile communications should be significantly improved compared to current 4G standards. In addition, signaling efficiency should be improved and latency should be greatly reduced compared to current standards.

[0007] In particular, leveraging the increased data rate and reduced latency of 5G, vehicle-to-everything (V2X) communication technologies are being implemented to support autonomous driving applications, such as wireless communication between vehicles, between vehicles and roadside infrastructure, between vehicles and pedestrians, etc.

[0008] Overview

[0009] A simplified overview related to one or more aspects disclosed herein is given below. Thus, the following overview should neither be considered an exhaustive survey of all contemplated aspects, nor should the following overview be considered to identify key or decisive elements related to all contemplated aspects or to delineate the scope associated with any particular aspect. Accordingly, the sole purpose of the following overview is to present in a simplified form certain concepts related to one or more aspects regarding the mechanisms disclosed herein prior to the detailed description given below.

[0010] In one aspect, a method for wireless positioning performed by a first user equipment (UE) includes: transmitting a request to perform a UE-UE positioning procedure with a second UE; receiving a radio resource configuration for the UE-UE positioning procedure, the radio resource configuration indicating a first radio resource for transmitting a positioning signal to the second UE and a second radio resource for receiving a positioning signal from the second UE; transmitting one or more first positioning signals to the second UE on the first radio resource; receiving one or more second positioning signals from the second UE on the second radio resource; and estimating a distance between the first UE and the second UE based at least on a transmission time of the one or more first positioning signals and an arrival time (ToA) of the one or more second positioning signals.

[0011] In one aspect, a method for wireless positioning performed by a base station includes: receiving a request to allocate radio resources for a UE-UE positioning procedure between a first UE and a second UE; and transmitting to the first UE a radio resource configuration for the UE-UE positioning procedure, the radio resource configuration indicating a first radio resource for transmitting a positioning signal to the second UE and a second radio resource for receiving a positioning signal from the second UE.

[0012] In one aspect, a first UE includes: a memory; at least one transceiver; and at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor configured to: cause the at least one transceiver to transmit a request to perform a UE-UE positioning procedure with a second UE; receive, via the at least one transceiver, a radio resource configuration for the UE-UE positioning procedure, the radio resource configuration indicating a first radio resource for transmitting a positioning signal to the second UE and a second radio resource for receiving a positioning signal from the second UE; cause the at least one transceiver to transmit one or more first positioning signals to the second UE on the first radio resource; receive, via the at least one transceiver, one or more second positioning signals from the second UE on the second radio resource; and estimate a distance between the first UE and the second UE based at least on a transmission time of the one or more first positioning signals and the ToA of the one or more second positioning signals.

[0013] In one aspect, a base station includes: a memory; at least one transceiver; and at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: receive, via the at least one transceiver, a request to allocate radio resources for a UE-UE positioning procedure between a first UE and a second UE; and cause the at least one transceiver to transmit to the first UE a radio resource configuration for the UE-UE positioning procedure, the radio resource configuration indicating a first radio resource for transmitting a positioning signal to the second UE and a second radio resource for receiving a positioning signal from the second UE.

[0014] In one aspect, a first UE includes: means for transmitting a request to perform a UE-UE positioning procedure with a second UE; means for receiving a radio resource configuration for the UE-UE positioning procedure, the radio resource configuration indicating a first radio resource for transmitting a positioning signal to the second UE and a second radio resource for receiving a positioning signal from the second UE; means for transmitting, on the first radio resource, one or more first positioning signals to the second UE; means for receiving, on the second radio resource, one or more second positioning signals from the second UE; and means for estimating a distance between the first UE and the second UE based at least on a transmission time of the one or more first positioning signals and a ToA of the one or more second positioning signals.

[0015] In one aspect, a base station includes: means for receiving a request to allocate radio resources for a UE-UE positioning procedure between a first UE and a second UE; and means for transmitting to the first UE a radio resource configuration for the UE-UE positioning procedure, the radio resource configuration indicating a first radio resource for transmitting a positioning signal to the second UE and a second radio resource for receiving a positioning signal from the second UE.

[0016] In one aspect, a non-transitory computer-readable medium stores computer-executable instructions that include: at least one instruction to instruct a first UE to transmit a request to perform a UE-UE positioning procedure with a second UE; at least one instruction to instruct the first UE to receive a radio resource configuration for the UE-UE positioning procedure, the radio resource configuration indicating a first radio resource for transmitting a positioning signal to the second UE and a second radio resource for receiving a positioning signal from the second UE; at least one instruction to instruct the first UE to transmit one or more first positioning signals to the second UE on the first radio resource; at least one instruction to instruct the first UE to receive one or more second positioning signals from the second UE on the second radio resource; and at least one instruction to instruct the first UE to estimate a distance between the first UE and the second UE based at least on a transmission time of the one or more first positioning signals and an arrival time (ToA) of the one or more second positioning signals.

[0017] In one aspect, a non-transitory computer-readable medium stores computer-executable instructions that include: at least one instruction to instruct a base station to receive a request to allocate radio resources for a UE-UE positioning procedure between a first UE and a second UE; and at least one instruction to instruct the base station to transmit a radio resource configuration for the UE-UE positioning procedure to the first UE, the radio resource configuration indicating a first radio resource for transmitting a positioning signal to the second UE and a second radio resource for receiving a positioning signal from the second UE.

[0018] Based on the drawings and the detailed description, other objects and advantages associated with the aspects disclosed herein will be apparent to those of ordinary skill in the art. Brief Description of the Drawings

[0020] The accompanying drawings are provided to assist in describing one or more aspects of the disclosed subject matter and are provided only for illustration of the examples and not limitation thereof:

[0021] Figure 1 An exemplary wireless communication system in accordance with one or more aspects of the present disclosure is illustrated.

[0022] Figure 2A and Figure 2B An example wireless network architecture in accordance with various aspects is illustrated.

[0023] Figures 3A to 3C are simplified block diagrams of several exemplary aspects of components that may be employed in a wireless communication node and configured to support communication as taught herein.

[0024] Figure 4An exemplary wireless communication system in accordance with aspects of the present disclosure is presented, where a vehicle user equipment (V-UE) is exchanging ranging signals with a roadside unit (RSU) and another V-UE.

[0025] Figure 5 is a timeline depicting a three-phase communication protocol in accordance with aspects of the present disclosure.

[0026] Figure 6 and Figure 7 illustrates a call flow of an exemplary base station assisted UE-UE positioning procedure in accordance with aspects of the present disclosure.

[0027] Figure 8 is a diagram of an exemplary base station assisted UE-UE positioning procedure among a serving base station, an initiating UE, and a target UE.

[0028] Figure 9 illustrates a call flow of an exemplary handover procedure during a base station assisted UE-UE positioning procedure in accordance with aspects of the present disclosure.

[0029] Figure 10 and 11 illustrates an exemplary method for wireless positioning in accordance with aspects of the present disclosure.

[0030] Detailed Description

[0031] Aspects of the present disclosure are provided in the following description of various examples provided for illustrative purposes and the associated drawings. Alternative aspects may be designed without departing from the scope of the present disclosure. Additionally, elements well known in the art will not be described in detail or will be omitted so as not to obscure relevant details of the present disclosure.

[0032] The terms "exemplary" and / or "example" are used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" and / or "example" is not necessarily to be construed as superior or better than other aspects. Similarly, the term "aspects of the present disclosure" does not require that all aspects of the present disclosure include the discussed features, advantages, or modes of operation.

[0033] Those skilled in the art will appreciate that the information and signals described below may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the following description may be represented, in part, depending on the specific application, in part, depending on the desired design, in part, depending on the corresponding technology, etc., by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0034] In addition, many aspects are described in the form of sequences of actions performed by elements of a computing device, for example. It will be recognized that the various actions described herein can be performed by special purpose circuitry (e.g., application specific integrated circuits (ASICs)), by program instructions being executed by one or more processors, or by a combination of the two. Additionally, the sequences of actions described herein can be considered to be fully embodied within any form of non-transitory computer-readable storage medium having stored therein a corresponding set of computer instructions that, when executed, cause or direct a relevant processor of the device to perform the functionality described herein. Thus, the various aspects of the present disclosure can be embodied in several different forms, all of which are contemplated as being within the scope of the claimed subject matter. Additionally, for each aspect described herein, any such aspect's corresponding form can be described herein as, for example, "logic configured to perform the described action."

[0035] As used herein, the terms "user equipment" (UE) and "base station" (BS) are not intended to be dedicated to or otherwise limited to any particular radio access technology (RAT) unless otherwise specified. In general, a UE can be any wireless communication device used by a user to communicate over a wireless communication network (e.g., in-vehicle computers, vehicle navigation devices, mobile phones, routers, tablet computers, laptop computers, tracking devices, wearable devices (e.g., smart watches, glasses, augmented reality (AR) / virtual reality (VR) headsets, etc.), vehicles (e.g., cars, motorcycles, bicycles, etc.), Internet of Things (IoT) devices, etc.). A UE can be mobile or can be stationary (e.g., at certain times) and can communicate with a radio access network (RAN). As used herein, the term "UE" can be interchangeably referred to as "mobile device", "access terminal" or "AT", "client device", "wireless device", "subscriber device", "subscriber terminal", "subscriber station", "user terminal" or "UT", "mobile terminal", "mobile station", or variants thereof. In general, a UE can communicate with a core network via a RAN, and through the core network, the UE can connect to an external network (such as the Internet) and to other UEs. Of course, other mechanisms for connecting to the core network and / or the Internet are also possible for a UE, such as via a wired access network, a wireless local area network (WLAN) network (e.g., based on IEEE 802.11, etc.).

[0036] In some cases, a UE may be classified as a vehicle UE (V-UE) or a pedestrian UE (P-UE). A V-UE is any in-vehicle wireless communication device, such as a navigation system, an alarm system, a head-up display (HUD), an in-vehicle computer, etc. Alternatively, a V-UE may be a portable wireless communication device (e.g., a cellular phone, a tablet computer, etc.) carried by a driver of a vehicle or a passenger in the vehicle. The term "V-UE" may refer to the wireless communication device in the vehicle or the vehicle itself, depending on the context. The term "vehicle" may refer to a truck, a car, a motorcycle, a train, an airplane, or any other motorized vehicle. A P-UE is a portable wireless communication device carried by a pedestrian (i.e., a user who is not driving or riding in a vehicle but may be riding a bicycle, a scooter, or other non-motorized vehicle).

[0037] A base station may operate according to one of several RATs to communicate with a UE depending on the network in which the base station is deployed and may alternatively be referred to as an access point (AP), a network node, a B node, an evolved B node (eNB), a next-generation eNB (ng-eNB), a new radio (NR) B node (also referred to as a gNB or gNodeB), etc. A base station may be primarily used to support wireless access by a UE, including supporting data, voice, and / or signaling connections for the supported UEs. In some systems, a base station may provide a pure edge node signaling function, while in other systems, a base station may provide additional control and / or network management functions. The communication link by which a UE may send signals to a base station is referred to as an uplink (UL) channel (e.g., a reverse traffic channel, a reverse control channel, an access channel, etc.). The communication link by which a base station may send signals to a UE is referred to as a downlink (DL) or a forward link channel (e.g., a paging channel, a control channel, a broadcast channel, a forward traffic channel, etc.). As used herein, the term traffic channel (TCH) may refer to a UL / reverse or a DL / forward traffic channel.

[0038] The term "base station" can refer to a single physical transmit receive point (TRP) or can refer to multiple physical TRPs that may or may not be co-located. For example, in the case where the term "base station" refers to a single physical TRP, the physical TRP can be a base station antenna corresponding to a cell (or a number of cell sectors) of the base station. In the case where the term "base station" refers to multiple co-located physical TRPs, the physical TRPs can be an antenna array of the base station (e.g., as in a multiple input multiple output (MIMO) system or in the case where the base station employs beamforming). In the case where the term "base station" refers to multiple non-co-located physical TRPs, the physical TRPs can be a distributed antenna system (DAS) (a network of spatially separated antennas connected via a transmission medium to a common source) or a remote radio head (RRH) (a remote base station connected to a serving base station). Alternatively, the non-co-located physical TRPs can be a serving base station that receives measurement reports from a UE and a neighbor base station whose reference RF signal (or simply "reference signal") the UE is measuring. Since a TRP is the point from which a base station transmits and receives wireless signals, as used herein, a reference to a transmission from a base station or a reception at a base station should be understood as a reference to a particular TRP of the base station.

[0039] In some implementations that support UE positioning, a base station may not support wireless access for a UE (e.g., may not support data, voice, and / or signaling connections for the UE), but can alternatively transmit to the UE reference signals to be measured by the UE and / or can receive and measure signals transmitted by the UE. Such a base station can be referred to as a positioning tower (e.g., in the case of transmitting signals to the UE) and / or as a position measurement unit (e.g., in the case of receiving and measuring signals from the UE).

[0040] An "RF signal" includes an electromagnetic wave of a given frequency that transmits information through the space between a transmitter and a receiver. As used herein, a transmitter can transmit a single "RF signal" or multiple "RF signals" to a receiver. However, due to the propagation characteristics of each RF signal through a multipath channel, a receiver can receive multiple "RF signals" corresponding to each transmitted RF signal. The same RF signal transmitted on different paths between a transmitter and a receiver can be referred to as a "multipath" RF signal. As used herein, an RF signal can also be referred to as a "wireless signal" or simply as a "signal", where it is clear from the context that the term "signal" refers to a wireless signal or an RF signal.

[0041] According to various aspects, Figure 1An exemplary wireless communication system 100 is described. The wireless communication system 100 (which may also be referred to as a wireless wide area network (WWAN)) may include various base stations 102 (labeled "BS") and various UEs 104. The base stations 102 may include macro cell base stations (high-power cell base stations) and / or small cell base stations (low-power cell base stations). In one aspect, the macro cell base stations 102 may include eNBs and / or ng-eNBs (where the wireless communication system 100 corresponds to an LTE network), or gNBs (where the wireless communication system 100 corresponds to an NR network), or a combination of both, and the small cell base stations may include femtocells, picocells, microcells, and so on.

[0042] The base stations 102 may collectively form a RAN and interface with a core network 174 (e.g., an evolved packet core (EPC) or a 5G core (5GC)) via a backhaul link 122, and via the core network 174 to one or more location servers 172 (which may be part of the core network 174 or may be external to the core network 174). Among other functions, the base stations 102 may also perform functions related to one or more of user data transfer, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS), subscriber and device tracking, RAN information management (RIM), paging, positioning, and delivery of alert messages. The base stations 102 may communicate with each other directly or indirectly (e.g., via the EPC / 5GC) via a backhaul link 134 (which may be wired or wireless).

[0043] Base station 102 can communicate wirelessly with UE 104. Each base station 102 can provide communication coverage for its respective geographical coverage area 110. In one aspect, one or more cells can be supported by the base station 102 in each geographical coverage area 110. A "cell" is a logical communication entity used to communicate with a base station (e.g., on a certain frequency resource, which is called carrier frequency, component carrier, carrier, frequency band, etc.), and can be associated with an identifier (e.g., physical cell identifier (PCI), enhanced cell identifier (ECI), virtual cell identifier (VCI), cell global identifier (CGI), etc.) to distinguish cells operating via the same or different carrier frequencies. In some cases, different cells can be configured according to different protocol types that can provide access for different types of UEs (e.g., machine type communication (MTC), narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB), or others). Since a cell is supported by a specific base station, the term "cell" can refer to either or both of the logical communication entity and the base station supporting the logical communication entity depending on the context. In some cases, in the sense that a carrier frequency can be detected and used for communication within a certain part of the geographical coverage area 110, the term "cell" can also refer to the geographical coverage area (e.g., sector) of the base station.

[0044] Although the geographical coverage areas 110 of adjacent macro cell base stations 102 can partially overlap (e.g., in a handover area), some geographical coverage areas 110 may be substantially overlapped by larger geographical coverage areas 110. For example, a small cell base station 102' (labeled "SC" for "small cell") can have a coverage area 110' that substantially overlaps with the geographical coverage areas 110 of one or more macro cell base stations 102. A network including both small cells and macro cell base stations can be referred to as a heterogeneous network. The heterogeneous network can also include a home eNB (HeNB), which can provide services to a restricted group called a closed subscriber group (CSG).

[0045] The communication link 120 between the base station 102 and the UE 104 can include an UL (also called reverse link) transmission from the UE 104 to the base station 102 and / or a downlink (DL) (also called forward link) transmission from the base station 102 to the UE 104. The communication link 120 can use MIMO antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link 120 can pass through one or more carrier frequencies. The allocation of carriers can be asymmetric with respect to the DL and UL (e.g., more or fewer carriers can be allocated to the DL compared to the UL).

[0046] The wireless communication system 100 may further include a wireless local area network (WLAN) access point (AP) 150 that communicates with a WLAN station (STA) 152 via a communication link 154 in an unlicensed spectrum (e.g., 5 GHz). When communicating in the unlicensed spectrum, the WLAN STA 152 and / or the WLAN AP 150 may perform a clear channel assessment (CCA) or a listen-before-talk (LBT) procedure before communicating to determine whether the channel is available.

[0047] The small cell base station 102' may operate in licensed and / or unlicensed spectrum. When operating in the unlicensed spectrum, the small cell base station 102' may employ LTE or NR technology and use the same 5 GHz unlicensed spectrum as that used by the WLAN AP 150. The small cell base station 102' adopting LTE / 5G in the unlicensed spectrum may boost the coverage of the access network and / or increase the capacity of the access network. NR in the unlicensed spectrum may be referred to as NR-U. LTE in the unlicensed spectrum may be referred to as LTE-U, licensed-assisted access (LAA), or MulteFire.

[0048] The wireless communication system 100 may further include a mmW base station 180 that may operate in mmW frequencies and / or near mmW frequencies to communicate with a UE 182. Extremely high frequency (EHF) is a part of RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. The radio waves in this band may be referred to as millimeter waves. Near mmW may be extended down to 3 GHz frequency with a 100 millimeter wavelength. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, which is also referred to as centimeter waves. Communications using the mmW / near mmW radio frequency band have high path loss and a relatively short range. The mmW base station 180 and the UE 182 may utilize beamforming (transmitting and / or receiving) on the mmW communication link 184 to compensate for the extremely high path loss and short range. Additionally, it will be appreciated that in an alternative configuration, one or more of the base stations 102 may also use mmW or near mmW and beamforming for transmission. Accordingly, it will be appreciated that the foregoing explanations are merely examples and should not be construed as limiting the various aspects disclosed herein.

[0049] Transmit beamforming is a technique for focusing RF signals in a specific direction. Conventionally, when a network node (e.g., a base station) broadcasts an RF signal, the network node broadcasts the signal omnidirectionally, i.e., in all directions. With transmit beamforming, the network node determines where a given target device (e.g., a UE) is located (relative to the transmitting network node) and projects a stronger downlink RF signal in that specific direction, thereby providing a faster (in terms of data rate) and stronger RF signal to the receiving device. To change the directivity of the RF signal during transmission, the network node can control the phase and relative amplitude of the RF signal at each of one or more transmitters that are broadcasting the RF signal. For example, the network node can use an antenna array (referred to as a "phased array" or "antenna array") that generates a beam of RF waves, and the beam of RF waves can be "steered" to point in different directions without physically moving the antennas. Specifically, the RF currents from the transmitters are fed to the individual antennas with the correct phase relationships so that the radio waves from the separate antennas add together in the desired direction to increase radiation, while canceling in the undesired directions to suppress radiation.

[0050] Transmit beams can be quasi-co-located, which means that they appear to have the same parameters to the receiver (e.g., a UE), regardless of whether the transmit antennas of the network node are physically co-located themselves. In NR, there are four types of quasi-co-location (QCL) relationships. Specifically, a given type of QCL relationship means that certain parameters of a second reference RF signal on a second beam can be derived from information about a source reference RF signal on a source beam. Thus, if the source reference RF signal is QCL type A, the receiver can use the source reference RF signal to estimate the Doppler frequency shift, Doppler spread, average delay, and delay spread of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL type B, the receiver can use the source reference RF signal to estimate the Doppler frequency shift and Doppler spread of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL type C, the receiver can use the source reference RF signal to estimate the Doppler frequency shift and average delay of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL type D, the receiver can use the source reference RF signal to estimate the spatial reception parameters of a second reference RF signal transmitted on the same channel.

[0051] In receive beamforming, the receiver uses receive beams to amplify the RF signals detected on a given channel. For example, the receiver can increase the gain setting of the antenna array and / or adjust the phase setting of the antenna array in a specific direction to amplify the RF signals received from that direction (e.g., increase its gain level). Thus, when the receiver is said to perform beamforming in a certain direction, it means that the beam gain in that direction is higher relative to the beam gains in other directions, or the beam gain in that direction is the highest compared to the beam gains of all other receive beams available to the receiver in that direction. This results in a stronger received signal strength for the RF signals received from that direction (e.g., reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-interference-plus-noise ratio (SINR), etc.).

[0052] Transmit beams and receive beams can be spatially related. Spatial relationship means that the parameters of the second beam (e.g., transmit or receive beam) for the second reference signal can be derived from the information about the first beam (e.g., receive beam or transmit beam) for the first reference signal. For example, a UE can use a specific receive beam to receive a reference downlink reference signal (e.g., synchronization signal block (SSB)) from a base station. The UE can then form a transmit beam based on the parameters of the receive beam to transmit an uplink reference signal (e.g., sounding reference signal (SRS)) to the base station.

[0053] Note that depending on the entity forming the "downlink" beam, the beam can be a transmit beam or a receive beam. For example, if the base station is forming a downlink beam to transmit a reference signal to the UE, the downlink beam is a transmit beam. However, if the UE is forming a downlink beam, the downlink beam is a receive beam for receiving the downlink reference signal. Similarly, depending on the entity forming the "uplink" beam, the beam can be a transmit beam or a receive beam. For example, if the base station is forming an uplink beam, the uplink beam is an uplink receive beam, and if the UE is forming an uplink beam, the uplink beam is an uplink transmit beam.

[0054] In 5G, the spectrum in which wireless nodes (e.g., base stations 102 / 180, UEs 104 / 182) operate is divided into multiple frequency ranges: FR1 (from 450 to 6000 MHz), FR2 (from 24250 to 52600 MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). The mmW band generally includes the FR2, FR3, and FR4 frequency ranges. Thus, the terms "mmW" and "FR2" or "FR3" or "FR4" can generally be used interchangeably.

[0055] In a multi-carrier system such as 5G, one of the carrier frequencies is referred to as the "primary carrier" or "anchor carrier" or "primary serving cell" or "PCell", and the remaining carrier frequencies are referred to as "secondary carriers" or "secondary serving cells" or "SCells". In carrier aggregation, the anchor carrier operates on the primary frequency (e.g., FR1) utilized by the UE 104 / 182 and on the cell in which the UE 104 / 182 performs the initial radio resource control (RRC) connection establishment procedure or initiates the RRC connection re-establishment procedure. The primary carrier carries all common control channels as well as UE-specific control channels, and can be a carrier in a licensed frequency (however, this is not always the case). The secondary carrier is a carrier that operates on a second frequency (e.g., FR2) and can be configured once an RRC connection is established between the UE 104 and the anchor carrier, and this carrier can be used to provide additional radio resources. In some cases, the secondary carrier can be a carrier in an unlicensed frequency. The secondary carrier may only contain necessary signaling information and signals. For example, UE-specific signaling information and signals may not exist in the secondary carrier because both the primary uplink and downlink carriers are typically UE-specific. This means that different UEs 104 / 182 in a cell can have different downlink primary carriers. The same holds true for the uplink primary carriers. The network is able to change the primary carrier of any UE 104 / 182 at any time. For example, this is done to balance the load on different carriers. Since the "serving cell" (whether it is a PCell or an SCell) corresponds to the carrier frequency / component carrier that a certain base station is using for communication, the terms "cell", "serving cell", "component carrier", "carrier frequency", etc. can be used interchangeably.

[0056] For example, still referring to Figure 1 , one of the frequencies utilized by the macro cell base station 102 can be the anchor carrier (or "PCell"), and the other frequencies utilized by this macro cell base station 102 and / or the mmW base station 180 can be secondary carriers ("SCells"). The simultaneous transmission and / or reception of multiple carriers enables the UE 104 / 182 to significantly increase its data transmission and / or reception rate. For example, two 20 MHz aggregated carriers in a multi-carrier system would theoretically result in a two-fold increase in the data rate (i.e., 40 MHz) compared to the data rate obtained by a single 20 MHz carrier.

[0057] The wireless communication system 100 may further include one or more UEs such as UE 190 that are indirectly connected to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links (sometimes referred to as "sidelinks"). In Figure 1In the example, the UE 190 has a D2D P2P link 192 with a UE 104 connected to a base station 102 (e.g., the UE 190 can thereby indirectly obtain cellular connectivity), and a D2D P2P link 194 with a WLAN STA 152 connected to a WLAN AP 150 (the UE 190 can thereby indirectly obtain WLAN-based Internet connectivity). In one example, the D2D P2P links 192 and 194 can use any well-known D2D RAT (such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), etc.) to support.

[0058] In particular, leveraging the increased data rate and reduced latency of NR, vehicle-to-everything (V2X) communication technologies are being implemented to support intelligent transportation system (ITS) applications, such as wireless communication between vehicles (vehicle-to-vehicle (V2V)), between a vehicle and roadside infrastructure (vehicle-to-infrastructure (V2I)), and between a vehicle and a pedestrian (vehicle-to-pedestrian (V2P)). The goal is to enable vehicles to sense their surrounding environment and communicate this information to other vehicles, infrastructure, and personal mobile devices. Such vehicle communication will achieve safety, mobility, and environmental improvements that current technologies cannot provide. Once fully implemented, it is expected that this technology will reduce collision-free vehicle collisions by up to 80%.

[0059] Still referring to Figure 1, the wireless communication system 100 may include multiple V-UEs 160, which may communicate with the base station 102 on the communication link 120 (e.g., using the Uu interface) or communicate with the mmW base station(s) 180 (not shown) on the communication link 184. The V-UE 160 may also communicate directly with each other on the wireless unicast sidelink 162, communicate directly with the roadside access point 164 (also referred to as "roadside unit" or "RSU") on the sidelink 166, or communicate with the UE 104 on the sidelink 168 using the P2P / D2D protocol (e.g., "PC5", LTE V2X D2D interface) or ProSe. Sidelink communication may be used for D2D media sharing, V2V communication, V2X communication (e.g., cellular V2X (cV2X) communication, enhanced V2X (eV2X) communication, etc.), emergency rescue applications, relative positioning, etc. One or more of the V-UEs 160 in a group of V-UEs 160 that utilize D2D communication may be within the geographical coverage area 110 of the base station 102. Other V-UEs 160 in such a group may be outside the geographical coverage area 110 of the base station 102 or may not be able to receive transmissions from the base station 102 for other reasons. In some cases, each group of V-UEs 160 that communicate via D2D communication may utilize a one-to-many (1:M) system, where each V-UE 160 transmits to every other V-UE 160 in the group. In some cases, the base station 102 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between the V-UEs 160 without involving the base station 102. Note that although Figure 1 illustrates two V-UEs 160 communicating on the sidelink, as will be understood, Figure 1 any two or more UEs illustrated in

[0060] may communicate on the sidelink, and the reference to V-UE 160 is merely exemplary. Figure 1 In one aspect, the V-UE 160 and

[0061] In one aspect, the sidelinks 162, 166, 168 may operate on a communication medium of interest, which may be shared with other vehicles and / or infrastructure access points and other communications between other RATs. The "medium" may include one or more frequency, time, and / or spatial communication resources associated with communication between one or more transmitter / receiver pairs (e.g., covering one or more channels across one or more carriers).

[0062] In some aspects, the sidelinks 162, 166, 168 may be cV2X links. The first generation of cV2X has been standardized in LTE, and the next generation is expected to be defined in NR. cV2X is a cellular technology that also enables device-to-device communication. In the United States and Europe, cV2X is expected to operate in the licensed ITS band in sub-6 GHz. Other bands may be allocated in other countries. Thus, as a specific example, the medium of interest utilized by the sidelinks 162, 166, 168 may correspond to at least a portion of the licensed ITS band in sub-6 GHz. However, the present disclosure is not limited to this band or cellular technology.

[0063] In one aspect, the sidelinks 162, 166, 168 may be dedicated short-range communication (DSRC) links. DSRC is a one-way or two-way short-range to medium-range wireless communication protocol that uses the wireless access for vehicular environments (WAVE) protocol (also known as IEEE 802.11p) for V2V, V2I, and V2P communications. IEEE 802.11p is an approved modification of the IEEE 802.11 standard and operates in the licensed ITS band at 5.9 GHz (5.85 - 5.925 GHz) in the United States. In Europe, IEEE 802.11p operates in the ITS G5A band (5.875 - 5.905 MHz). Other bands may be allocated in other countries. The V2V communication described above occurs on a secure channel, which is typically a 10 MHz channel dedicated for security purposes in the United States. The remainder of the DSRC band (total bandwidth is 75 MHz) is intended for other services of interest to drivers, such as road rules, tolling, parking automation, etc. Thus, as a specific example, the medium of interest utilized by the sidelinks 162, 166, 168 may correspond to at least a portion of the licensed ITS band at 5.9 GHz.

[0064] Alternatively, the medium of interest may correspond to at least a portion of an unlicensed frequency band shared among various RATs. Although different licensed frequency bands have been reserved for certain communication systems (e.g., reserved by government entities such as the Federal Communications Commission (FCC) in the United States), these systems, especially those employing small cell access points, have recently extended their operations into unlicensed frequency bands, such as the Unlicensed National Information Infrastructure (U-NII) bands used by wireless local area network (WLAN) technologies (most notably the IEEE 802.11x WLAN technologies commonly referred to as "Wi-Fi"). Example systems of this type include different variants of CDMA systems, TDMA systems, FDMA systems, orthogonal FDMA (OFDMA) systems, single carrier FDMA (SC-FDMA) systems, and so on.

[0065] Communication between V-UEs 160 is referred to as V2V communication, communication between a V-UE 160 and one or more roadside access points 164 is referred to as V2I communication, and communication between a V-UE 160 and one or more UEs 104 (where these UEs 104 are P-UEs) is referred to as V2P communication. V2V communication between V-UEs 160 may include, for example, information regarding the location, speed, acceleration, heading, and other vehicle data of these V-UEs 160. V2I information received at a V-UE 160 from one or more roadside access points 164 may include, for example, road rules, parking automation information, etc. V2P communication between a V-UE 160 and a UE 104 may include information regarding, for example, the location, speed, acceleration, and heading of the V-UE 160 and the location, speed (e.g., in the case where the UE 104 is carried by a user on a bicycle), and heading of the UE 104.

[0066] Note that although Figure 1 only two of the UEs are illustrated as V-UEs (V-UE 160), any of the illustrated UEs (e.g., UEs 104, 152, 182, 190) can be a V-UE. Additionally, although Figure 1The description only describes some UEs as being able to communicate with other UEs (e.g., V-UE 160, UE 190) on the sidelink, but as will be understood, any of the illustrated UEs can be able to communicate on the sidelink. Additionally, although only UE 182 is described as being able to perform beamforming, any of the illustrated UEs (including V-UE 160) can be able to perform beamforming. In the case where V-UE 160s are able to perform beamforming, they can beamform towards each other (i.e., towards other V-UE 160s), towards the roadside access point 164, towards other UEs (e.g., UE 104, 152, 182, 190), etc. Thus, in some scenarios, V-UE 160s can utilize beamforming on sidelinks 162, 166, and 168.

[0067] According to various aspects, Figure 2A An exemplary wireless network structure 200 is illustrated. For example, 5GC 210 (also referred to as Next Generation Core (NGC)) can be functionally regarded as a control plane function (C-plane) 214 (e.g., UE registration, authentication, network access, gateway selection, etc.) and a user plane function (U-plane) 212 (e.g., UE gateway function, access to data networks, IP routing, etc.), which operate in cooperation to form the core network. The user plane interface (NG-U) 213 and the control plane interface (NG-C) 215 connect gNB 222 to 5GC 210, specifically to the user plane function 212 and the control plane function 214 respectively. In an additional configuration, ng-eNB 224 can also be connected to 5GC210 via the NG-C 215 to the control plane function 214 and the NG-U 213 to the user plane function 212. Additionally, ng-eNB 224 can communicate directly with gNB 222 via a backhaul connection 223. In some configurations, the new RAN220 can have only one or more gNB 222s, while other configurations include both one or more ng-eNB 224s and one or more gNB 222s. gNB 222 or ng-eNB 224 (or both) can communicate with UE 204 (e.g., any UE described herein). In one aspect, two or more UEs 204 can communicate with each other on a wireless unicast sidelink 242, which can correspond to Figure 1 the wireless unicast sidelink 162 in

[0068] Another optional aspect may include a location server 230 that may be in communication with the 5GC 210 to provide location assistance for the UE 204. The location server 230 may be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules scaled across multiple physical servers, etc.), or alternatively may each correspond to a single server. The location server 230 may be configured to support one or more location services for the UE 204, and the UE 204 is capable of connecting to the location server 230 via the core network, 5GC 210, and / or via the Internet (not illustrated). Additionally, the location server 230 may be integrated into a component of the core network, or alternatively may be external to the core network.

[0069] In accordance with various aspects, Figure 2B illustrate another example wireless network architecture 250. For example, the 5GC 260 may be functionally viewed as a control plane function (provided by the Access and Mobility Management Function (AMF) 264) and a user plane function (provided by the User Plane Function (UPF) 262), which operate in concert to form the core network (i.e., 5GC 260). The user plane interface 263 and the control plane interface 265 connect the ng-eNB 224 to the 5GC 260, specifically to the UPF 262 and the AMF 264 respectively. In an additional configuration, the gNB 222 may also be connected to the 5GC 260 via the control plane interface 265 to the AMF 264 and the user plane interface 263 to the UPF 262. Additionally, the ng-eNB 224 may communicate directly with the gNB 222 via a backhaul connection 223 with or without direct connectivity of the gNB to the 5GC 260. In some configurations, the new RAN 220 may have only one or more gNBs 222, while other configurations include both one or more ng-eNBs 224 and one or more gNBs 222. The base stations of the new RAN 220 communicate with the AMF 264 via the N2 interface and with the UPF 262 via the N3 interface. The gNB 222 or the ng-eNB 224 (or both) may communicate with the UE 204 (e.g., any UE described herein). In one aspect, two or more UEs 204 may communicate with each other on a wireless unicast sidelink 242, which may correspond to Figure 1 the wireless unicast sidelink 162 in

[0070] The functions of the AMF 264 include registration management, connection management, reachability management, mobility management, lawful interception, transmission of session management (SM) messages between the UE 204 and the session management function (SMF) 266, transparent proxy service for routing SM messages, access authentication and access authorization, transmission of short message service (SMS) messages between the UE 204 and the short message service function (SMSF) (not shown), and security anchor functionality (SEAF). The AMF 264 also interacts with the authentication server function (AUSF) (not shown) and the UE 204, and receives the intermediate key established as a result of the UE 204 authentication process. In the case of authentication based on a UMTS (Universal Mobile Telecommunications System) subscriber identity module (USIM), the AMF 264 retrieves the security material from the AUSF. The functions of the AMF 264 also include security context management (SCM). The SCM receives a key from the SEAF, which the SCM uses to derive the access network - specific key. The functionality of the AMF 264 also includes: location service management for regulatory services, transmission of location service messages between the UE 204 and the location management function (LMF) 270 (which acts as the location server 230), transmission of location service messages between the new RAN 220 and the LMF 270, EPS bearer identifier allocation for interoperability with the evolved packet system (EPS), and UE 204 mobility event notification. In addition, the AMF 164 also supports the functionality of non - 3GPP access networks.

[0071] The functions of the UPF 262 include: acting as an anchor for intra - RAT / inter - RAT mobility (when applicable), acting as the external protocol data unit (PDU) session point for the interconnection to the data network (not shown), providing packet routing and forwarding, packet inspection, user plane policy rule enforcement (e.g., gating, redirection, traffic steering), lawful interception (user plane collection), traffic usage reporting, quality of service (QoS) handling of the user plane (e.g., UL / DL rate enforcement, reflexive QoS marking in DL), UL traffic verification (mapping of service data flow (SDF) to QoS flow), transport - level packet marking in UL and DL, DL packet buffering and DL data notification triggering, and sending and forwarding one or more end markers to the source RAN node. The UPF 262 may also support the transmission of location service messages on the user plane between the UE 204 and a location server such as the secure user plane location (SUPL) location platform (SLP) 272.

[0072] The functions of the SMF 266 include session management, UE Internet Protocol (IP) address allocation and management, selection and control of the user plane function, traffic steering configuration at the UPF 262 for routing traffic to the correct destination, partial control of policy enforcement and QoS, and downlink data notification. The interface used by the SMF 266 to communicate with the AMF 264 is referred to as the N11 interface.

[0073] Another optional aspect may include an LMF 270, which may communicate with the 5GC 260 to provide location assistance for the UE 204. The LMF 270 may be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules scaled across multiple physical servers, etc.), or alternatively may each correspond to a single server. The LMF 270 may be configured to support one or more location services for the UE 204, and the UE 204 can be connected to the LMF 270 via the core network, the 5GC 260, and / or via the Internet (not illustrated). The SLP 272 may support similar functions as the LMF 270, but the LMF 270 may communicate with the AMF 264, the new RAN 220, and the UE 204 on the control plane (e.g., using interfaces and protocols designed to convey signaling messages without conveying voice or data), and the SLP 272 may communicate with the UE 204 and external clients ( Figure 2B not shown in the figure) on the user plane (e.g., using protocols designed to carry voice and / or data, such as Transmission Control Protocol (TCP) and / or IP).

[0074] Figure 3A 、 3B Figures 3A, 3B, and 3C illustrate several exemplary components (represented by corresponding boxes) that may be incorporated into a UE 302 (which may correspond to any UE described herein), a base station 304 (which may correspond to any base station described herein), and a network entity 306 (which may correspond to or embody any network function described herein, including the location server 230, the LMF 270, and the SLP 272) to support file transfer operations as taught herein. It will be appreciated that these components may be implemented in different types of devices in different implementations (e.g., in an ASIC, in a system-on-chip (SoC), etc.). The illustrated components may also be incorporated into other devices in the communication system. For example, other devices in the system may include components similar to those described to provide similar functionality. Additionally, a given device may include one or more of these components. For example, a device may include multiple transceiver components that enable the device to operate on multiple carriers and / or communicate via different technologies.

[0075] The UE 302 and the base station 304 each include a wireless wide area network (WWAN) transceiver 310 and 350 respectively, which are configured to communicate via one or more wireless communication networks (not shown), such as an NR network, an LTE network, a GSM network, etc. The WWAN transceivers 310 and 350 can be respectively connected to one or more antennas 316 and 356 for communicating with other network nodes (such as other UEs, access points, base stations (e.g., eNBs, gNBs), etc.) via at least one specified RAT (e.g., NR, LTE, GSM, etc.) on an interested wireless communication medium (e.g., a set of time / frequency resources in a specific spectrum). The WWAN transceivers 310 and 350 can be respectively configured in various ways according to the specified RAT for transmitting and encoding signals 318 and 358 (e.g., messages, indications, information, etc.), and vice versa, for receiving and decoding signals 318 and 358 (e.g., messages, indications, information, pilots, etc.). Specifically, the transceivers 310 and 350 respectively include one or more transmitters 314 and 354 for transmitting and encoding signals 318 and 358, and respectively include one or more receivers 312 and 352 for receiving and decoding signals 318 and 358.

[0076] In at least some cases, the UE 302 and the base station 304 also include wireless local area network (WLAN) transceivers 320 and 360 respectively. The WLAN transceivers 320 and 360 can be respectively connected to one or more antennas 326 and 366 for communicating with other network nodes (such as other UEs, access points, base stations, etc.) via at least one specified RAT (e.g., WiFi, LTE-D, etc.) on an interested wireless communication medium. The WLAN transceivers 320 and 360 can be respectively configured in various ways according to the specified RAT for transmitting and encoding signals 328 and 368 (e.g., messages, indications, information, etc.), and vice versa, for receiving and decoding signals 328 and 368 (e.g., messages, indications, information, pilots, etc.). Specifically, the transceivers 320 and 360 respectively include one or more transmitters 324 and 364 for transmitting and encoding signals 328 and 368, and respectively include one or more receivers 322 and 362 for receiving and decoding signals 328 and 368.

[0077] A transceiver circuit system including at least one transmitter and at least one receiver may, in some implementations, include an integrated device (e.g., a transmitter circuit and a receiver circuit implemented as a single communication device), may, in some implementations, include separate transmitter devices and separate receiver devices, or may be implemented otherwise in other implementations. In one aspect, the transmitter may include or be coupled to a plurality of antennas such as an antenna array (e.g., antennas 316, 326, 356, 366), and the plurality of antennas permit the corresponding device to perform transmit "beamforming" as described herein. Similarly, the receiver may include or be coupled to a plurality of antennas such as an antenna array (e.g., antennas 316, 326, 356, 366), and the plurality of antennas permit the corresponding device to perform receive beamforming as described herein. In one aspect, the transmitter and the receiver may share the same plurality of antennas (e.g., antennas 316, 326, 356, 366) such that the corresponding device can only receive or transmit at a given time, rather than both simultaneously. The wireless communication devices of UE 302 and / or base station 304 (e.g., one or both of transceivers 310 and 320 and / or one or both of transceivers 350 and 360) may also include a network listening module (NLM) and the like for performing various measurements.

[0078] At least in some cases, UE 302 and base station 304 also include satellite positioning system (SPS) receivers 330 and 370. SPS receivers 330 and 370 may be respectively connected to one or more antennas 336 and 376 for respectively receiving SPS signals 338 and 378 (such as Global Positioning System (GPS) signals, Global Navigation Satellite System (GLONASS) signals, Galileo signals, Beidou signals, Indian Regional Navigation Satellite System (NAVIC), Quasi-Zenith Satellite System (QZSS), etc.). SPS receivers 330 and 370 may respectively include any suitable hardware and / or software for receiving and processing SPS signals 338 and 378. SPS receivers 330 and 370 request information and operations from other systems as appropriate and perform the necessary calculations to determine the positions of UE 302 and base station 304 using measurements obtained by any suitable SPS algorithm.

[0079] Base station 304 and network entity 306 each respectively include at least one network interface 380 and 390 for communicating with other network entities. For example, network interfaces 380 and 390 (e.g., one or more network access ports) may be configured to communicate with one or more network entities via a wired-based backhaul connection or a wireless backhaul connection. In some aspects, network interfaces 380 and 390 may be implemented as transceivers configured to support wired-based signal communication or wireless signal communication. The communication may involve, for example, sending and receiving: messages, parameters, and / or other types of information.

[0080] The UE 302, the base station 304, and the network entity 306 also include other components that can be used in conjunction with the operations disclosed herein. The UE 302 includes processor circuitry that implements a processing system 332 for providing, for example, functionality related to wireless positioning and for providing other processing functionality. The base station 304 includes a processing system 384 for providing, for example, functionality related to wireless positioning as disclosed herein and for providing other processing functionality. The network entity 306 includes a processing system 394 for providing, for example, functionality related to wireless positioning as disclosed herein and for providing other processing functionality. In one aspect, the processing systems 332, 384, and 394 can include, for example, one or more general-purpose processors, multi-core processors, ASICs, digital signal processors (DSPs), field programmable gate arrays (FPGAs), or other programmable logic devices or processing circuitry.

[0081] The UE 302, the base station 304, and the network entity 306 include memory circuitry that implements memory components 340, 386, and 396 (e.g., each including a memory device) for maintaining information (e.g., information indicating reserved resources, thresholds, parameters, etc.). In some cases, the UE 302, the base station 304, and the network entity 306 can include positioning components 342, 388, and 398, respectively. The positioning components 342, 388, and 398 can be hardware circuits that are part of or coupled to the processing systems 332, 384, and 394, respectively, and that, when executed, cause the UE 302, the base station 304, and the network entity 306 to perform the functionality described herein. In other aspects, the positioning components 342, 388, and 398 can be external to the processing systems 332, 384, and 394 (e.g., part of a modem processing system, integrated with another processing system, etc.). Alternatively, the positioning components 342, 388, and 398 can be memory modules stored in the memory components 340, 386, and 396, respectively, that, when executed by the processing systems 332, 384, and 394 (or a modem processing system, another processing system, etc.), cause the UE 302, the base station 304, and the network entity 306 to perform the functionality described herein. Figure 3A The possible locations of the positioning component 342 are illustrated, and the positioning component 342 can be part of the WWAN transceiver 310, the memory component 340, the processing system 332, or any combination thereof, or can be a stand-alone component. Figure 3B The possible locations of the positioning component 388 are illustrated, and the positioning component 388 can be part of the WWAN transceiver 350, the memory component 386, the processing system 384, or any combination thereof, or can be a stand-alone component. Figure 3CThe possible locations of the positioning component 398 are explained, which may be part of one or more of the network interfaces 390, the memory components 396, the processing system 394, or any combination thereof, or may be a stand-alone component.

[0082] The UE 302 may include one or more sensors 344 coupled to the processing system 332 to provide movement and / or orientation information that is independent of the motion data derived from the signals received by the WWAN transceiver 310, the WLAN transceiver 320, and / or the SPS receiver 330. As an example, the sensors 344 may include an accelerometer (e.g., a microelectromechanical systems (MEMS) device), a gyroscope, a geomagnetic sensor (e.g., a compass), an altimeter (e.g., a barometric altimeter), and / or any other type of motion detection sensor. Additionally, the sensors 344 may include multiple different types of devices and combine their outputs to provide motion information. For example, the sensors 344 may use a combination of a multi-axis accelerometer and an orientation sensor to provide the ability to calculate positioning in a 2D and / or 3D coordinate system.

[0083] Furthermore, the UE 302 includes a user interface 346 for providing indications to the user (e.g., audible and / or visual indications) and / or for receiving user input (e.g., when the user actuates a sensing device such as a keypad, a touch screen, a microphone, etc.). Although not shown, the base station 304 and the network entity 306 may also include a user interface.

[0084] Referring more specifically to processing system 384, in the downlink, IP packets from network entity 306 may be provided to processing system 384. Processing system 384 may implement functionality for the RRC layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, and Medium Access Control (MAC) layer. Processing system 384 may provide RRC layer functionality associated with system information (e.g., Master Information Block (MIB), System Information Block (SIB)) broadcast, RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-RAT mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression / decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with transfer of upper layer packet data units (PDUs), error correction via Automatic Repeat reQuest (ARQ), concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and re-ordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, scheduling information reporting, error correction, priority handling, and logical channel prioritization.

[0085] Transmitter 354 and receiver 352 may implement layer-1 functionality associated with various signal processing functions. Layer-1, including the Physical (PHY) layer, may include error detection on the transport channel, forward error correction (FEC) encoding / decoding of the transport channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. Transmitter 354 handles the mapping to the signal constellation based on various modulation schemes (e.g., Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying (QPSK), M-Phase Shift Keying (M-PSK), M-Quadrature Amplitude Modulation (M-QAM)). The encoded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to Orthogonal Frequency Division Multiplexing (OFDM) subcarriers, multiplexed with reference signals (e.g., pilots) in the time domain and / or frequency domain, and then combined together using the Inverse Fast Fourier Transform (IFFT) to generate a physical channel carrying a time-domain OFDM symbol stream. The OFDM symbol stream is space precoded to generate multiple spatial streams. Channel estimates from the channel estimator may be used to determine the coding and modulation schemes and for spatial processing. The channel estimates may be derived from reference signals transmitted by UE 302 and / or channel status feedback. Each spatial stream may then be provided to one or more different antennas 356. Transmitter 354 may modulate an RF carrier with the respective spatial stream for transmission.

[0086] At the UE 302, the receiver 312 receives signals via its respective antenna(s) 316. The receiver 312 recovers the information modulated onto the RF carrier and provides the information to the processing system 332. The transmitter 314 and the receiver 312 implement layer 1 functionality associated with various signal processing functions. The receiver 312 may perform spatial processing on the information to recover any spatial streams destined for the UE 302. If there are multiple spatial streams destined for the UE 302, they may be combined by the receiver 312 into a single OFDM symbol stream. The receiver 312 then uses a Fast Fourier Transform (FFT) to transform the OFDM symbol stream from the time domain to the frequency domain. The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols and reference signals on each subcarrier are recovered and demodulated by determining the signal constellation points most likely transmitted by the base station 304. These soft decisions may be based on channel estimates calculated by the channel estimator. These soft decisions are then decoded and deinterleaved to recover the original data and control signals transmitted by the base station 304 on the physical channel. These data and control signals are then provided to the processing system 332 that implements layer 3 and layer 2 functionality.

[0087] In the uplink, the processing system 332 provides demultiplexing between transport channels and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the core network. The processing system 332 is also responsible for error detection.

[0088] Similar to the functionality described in connection with downlink transmissions by the base station 304, the processing system 332 provides RRC layer functionality associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functionality associated with header compression / decompression and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with transfer of upper layer PDUs, error correction via ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing MAC SDUs onto transport blocks (TBs), demultiplexing MAC SDUs from TBs, scheduling information reporting, error correction via Hybrid Automatic Repeat Request (HARQ), priority handling, and logical channel prioritization.

[0089] Channel estimates derived by the channel estimator from reference signals or feedback transmitted by the base station 304 may be used by the transmitter 314 to select appropriate coding and modulation schemes and to facilitate spatial processing. The spatial streams generated by the transmitter 314 may be provided to the respective antenna(s) 316. The transmitter 314 may modulate the RF carrier with the respective spatial streams for transmission.

[0090] The uplink transmission is processed at the base station 304 in a manner similar to that described in connection with the receiver function at the UE 302. The receiver 352 receives signals via its respective antenna(s) 356. The receiver 352 recovers the information modulated onto the RF carrier and provides the information to the processing system 384.

[0091] In the uplink, the processing system 384 provides demultiplexing between the transport channel and the logical channel, packet reconstitution, deciphering, header decompression, control signal processing to recover the IP packets from the UE 302. The IP packets from the processing system 384 may be provided to the core network. The processing system 384 is also responsible for error detection.

[0092] For convenience, the UE 302, the base station 304, and / or the network entity 306 are shown in Figures 3A - 3C as including various components that may be configured according to the various examples described herein. However, it will be appreciated that the illustrated blocks may have different functionality in different designs.

[0093] The various components of the UE 302, the base station 304, and the network entity 306 may communicate with each other respectively on data buses 334, 382, and 392. Figure 3A The components of -C may be implemented in various ways. In some implementations, Figures 3A - 3CThe components may be implemented in one or more circuits, such as, by way of example, one or more processors and / or one or more ASICs (which may include one or more processors). Here, each circuit may use and / or incorporate at least one memory component for storing information or executable code used by the circuit to provide this functionality. For example, some or all of the functionality represented by blocks 310 to 346 may be implemented by a processor and (a) memory component(s) of UE 302 (e.g., by executing appropriate code and / or by appropriately configuring the processor components). Similarly, some or all of the functionality represented by blocks 350 to 388 may be implemented by a processor and memory component(s) of base station 304 (e.g., by executing appropriate code and / or by appropriately configuring the processor components). Additionally, some or all of the functionality represented by blocks 390 to 398 may be implemented by a processor and (a) memory component(s) of network entity 306 (e.g., by executing appropriate code and / or by appropriately configuring the processor components). For simplicity, various operations, actions, and / or functions are described herein as being “performed by the UE,” “performed by the base station,” “performed by the positioning entity,” etc. However, as will be appreciated, such operations, actions, and / or functions may actually be performed by specific components or combinations of components of the UE, base station, positioning entity, etc., such as processing systems 332, 384, 394, transceivers 310, 320, 350, and 360, memory components 340, 386, and 396, positioning components 342, 388, and 398, etc.

[0094] As mentioned above, one of the use cases for sidelink communication between UEs (whether V-UEs or other types of UEs) is relative positioning, referred to as “UE-to-UE” or “UE-UE” positioning. In a UE-UE positioning scenario, two or more UEs may exchange ranging signals between them to determine the distance(s) (and possibly also the angle(s)) therebetween. A V-UE may also exchange ranging signals with a roadside unit (RSU) to determine its distance (and possibly also angle) from the roadside unit.

[0095] Figure 4An exemplary wireless communication system 400 in accordance with aspects of the present disclosure is illustrated, where V-UE 404 and RSU 410 and another V-UE 406 are performing a UE-UE positioning procedure. The UE-UE positioning procedure is similar to a round-trip time (RTT) positioning procedure, where a UE measures the time of arrival (ToA) of a downlink reference signal from a base station and responds with an uplink reference signal to be measured by the base station. Based on the difference between the transmission time of the downlink reference signal and the reception time of the uplink reference signal, the base station, UE, or location server can calculate the RTT or time of flight between the base station and the UE. Based on the RTT or time of flight and the speed of light, the base station, UE, or location server can estimate the distance between the UE and the base station.

[0096] Reference Figure 4 , a broadband (e.g., FR1) ranging signal (e.g., Zadoff Chu sequence) is transmitted by two endpoints (e.g., V-UE 404 and RSU 410 and / or V-UE 404 and V-UE 406). In one aspect, the ranging signal can be a positioning reference signal (PRS) as defined in LTE and NR. Upon receiving the ranging signal (referred to as the "measured ranging signal") from V-UE 404, RSU 410 and / or V-UE 406 estimate the ToA of the measured ranging signal. RSU 410 and / or V-UE 406 then respond by sending a response ranging signal to V-UE 404. The response ranging signal identifies the measured ranging signal to which it is responding and may include the calculated ToA of the measured ranging signal.

[0097] V-UE 404 calculates the ToA of the response ranging signal(s) and uses those ToA and the transmission time(s) of the measured ranging signal(s) to determine the RTT or time of flight between V-UE 404 and RSU 410 and / or V-UE 406. If available, V-UE 404 can also use the ToA of the measured ranging signal(s) received in the response ranging signal(s). Based on the RTT or time of flight and the speed of light, V-UE 404 (or other positioning entity) can estimate the distance between itself and RSU 410 and / or V-UE 406.

[0098] Note that this positioning procedure assumes that the entities involved (V-UEs 404 and 406, RSU 410) are time synchronized (i.e., their system frame times are the same or a known offset relative to other entities). Additionally, although Figure 4 two V-UEs are illustrated, as will be appreciated, they do not need to be V-UEs and instead can be any other type of UE.

[0099] Referring more specifically to the transmission of ranging signals, a three-phase protocol can be used to transmit ranging signals for UE-UE positioning. Figure 5 Illustrated is a timeline 500 of a three-phase protocol in accordance with aspects of the present disclosure. As Figure 5 shown, the three-phase protocol occurs periodically (such as once per second). In the first phase, the transmitter (e.g., V-UE 404, RSU 410) broadcasts the relative positions of its antenna(s) (relative to the center position of the transmitter), the identifier (ID) of each sequence (i.e., ranging signal) to be transmitted via the antenna(s) in the second phase, and the time / frequency resources on which these sequences will be transmitted in the second phase.

[0100] In the second phase, the transmitter transmits a wideband sequence (e.g., ranging signal) with the determined sequence ID on the determined time / frequency resources. In the third phase, the transmitter broadcasts its own GPS position (if available), the pseudorange to one or more satellites, and / or the orientation it had during the second phase. It may also broadcast the ToA from the second phase. That is, it broadcasts the ToA of any PRS received during the second phase. Note that for V2I positioning, only the RSU needs to perform the third phase.

[0101] In one aspect, all V-UEs and RSUs can be configured (e.g., according to applicable standards) to follow the three-phase protocol. Thus, during each phase, the transmitter can also receive signals from other V-UEs / RSUs that contain information of the same type as the information transmitted by the transmitter. In this way, both the transmitter and the receiver can estimate the distance between itself and other V-UEs / RSUs.

[0102] The present disclosure provides techniques for base station-assisted UE-UE positioning. To enable base station-assisted UE-UE positioning, various aspects need to be defined, such as the (sub)scriptions required for UE-UE positioning, proximity detection and notification, UE-UE positioning requests and configurations, base station assistance for UE-UE positioning measurements, radio resource configuration for UE-UE positioning measurements, mobility (e.g., handover) procedures, and UE-UE positioning in the RRC_INACTIVE (RRC-inactive) mode.

[0103] Regarding the subscription(s) required for base station-assisted UE-UE positioning, the subscription for base station-assisted UE-UE positioning should be added to the UE subscription data in the UE's Unified Data Management (UDM) and / or Home Subscriber Server (HSS). The UDM supports the Authentication Credential Repository and Processing Function (ARPF) and stores the long-term security credentials used in the authentication for Authentication and Key Agreement (AKA). Additionally, it stores the subscription information. The HSS is the primary user database of the IP Multimedia Subsystem (IMS) network entity that supports the handling of calls and sessions.

[0104] The subscription for base station-assisted UE-UE positioning may include features such as the ability and permission to measure signals from other UEs, be measured by other UEs, and receive and / or provide proximity notifications. The subscription may also include group information for in-group proximity detection (i.e., notification when a UE is within a certain proximity to another group member). A UE group can be two or more UEs that have some implicit or explicit association with each other. Examples of explicit associations are groups such as family members, friends, colleagues, etc., which explicitly identify the other members of the group as belonging to the group. An example of an implicit association is users within a given geographical area, who may optionally meet some other criteria, such as the type of UE, the brand of the UE, the service provider, etc.

[0105] The type of UE (e.g., V-UE, such as a road vehicle) that will participate in UE-UE positioning should also be indicated to the network (such as during NAS registration). Thus, when a UE registers with the network and has a subscription for base station-assisted UE-UE positioning, it can also provide its UE type to the network (if not already stored with its subscription data). Based on the subscription and UE type (e.g., from the UDM and / or HSS), the AMF (e.g., AMF 264) can notify the base station serving the UE whether UE-UE positioning is applicable to the UE and, if so, which UE-UE positioning is supported. The AMF can notify this information to the base station in, for example, the NG Application Protocol (NGAP) UE context setup or context modification procedure.

[0106] Reference base station assisted proximity detection and notification. Before two UEs can participate in UE-UE positioning, they need to know that they are close enough to each other to perform UE-UE positioning. The base station can be used to detect whether two or more UEs are within sufficient proximity to perform UE-UE positioning. There are different types of proximity, and the type of proximity that the UE wishes to be notified of can be determined by the UE's subscription. The first type is in-cell proximity, where two UEs are located in the same cell. This can be detected based on two or more UEs having the same beam ID and / or timing advance (TA), reporting the same or similar RSRP and / or RSRQ measurements, having similar characteristics of uplink signals (e.g., SRS, phase-tracking reference signal (PTRS)), or any combination thereof. The second type of proximity is inter-cell, in-base-station proximity, where two or more UEs are located in different cells supported by the same base station. In addition to the parameters required for in-cell proximity, distributed unit (DU) - to - DU coordination is also required. The DU is also known as the remote radio head (RRH). The third type of proximity is inter-base-station proximity, where two or more UEs are served by different base stations. In this case, inter-base-station coordination is required with the assistance of a location server (e.g., location server 230, LMF 270, SLP 272). In one aspect, two or more UEs can discover their proximity to each other based on a pre - established UE-UE location configuration.

[0107] When one of the above proximity types is detected, the base station can notify the neighboring UEs. This can be achieved through unicast signaling to each UE or broadcast / multicast signaling (similar to paging). The notification should include the identifier(s) of the neighboring UE(s). Once proximity is detected, one or more neighboring UEs can request base station assisted UE-UE positioning. When two UEs are no longer in proximity to each other, they should also be notified.

[0108] Figure 6 Call flow 600 of an exemplary base station assisted UE-UE positioning procedure in accordance with aspects of the present disclosure is illustrated. In Figure 6 the example, the initiating UE 604-1 (e.g., any UE described herein) has obtained the identifier (ID) of the target UE 604-2 (e.g., any other UE described herein) from the serving base station, for example, based on a proximity notification, and includes it in the positioning request.

[0109] In Phase 1, the initiating UE 604-1 (labeled "UE1") requests UE-UE positioning with the target UE 604-2 (labeled "UE2") by sending an LPP message to the LMF 670. The positioning request includes the identifier of the target UE 604-2 (denoted as "UE2 ID"). In response, in Phase 2, the LMF 670 requests the serving base station of the initiating UE 604-1 (labeled "serving gNB of UE1") to configure radio resources for UE-UE positioning. This request can be sent on LPP type A (LPPa) or NR positioning protocol type A (NRPPa) signaling (as shown).

[0110] In Phases 3 and 4, since the target UE 604-2 is served by the neighboring base station 602-2 (labeled "gNB2"), the serving base station 602-1 sends a UE-UE positioning configuration request to the neighboring base station 602-2. The neighboring base station 602-2 configures positioning resources for the target UE 604-2 and sends the positioning configuration to the serving base station 602-1.

[0111] In Phase 5, the serving base station 602-1 sends a UE-UE positioning resource response to the LMF 670, which identifies the positioning resources that have been allocated by the serving base station 602-1 and the neighboring base station 602-2. In Phase 6, the LMF 670 sends an LPP response to the serving base station 602-1 for forwarding to the initiating UE 604-1, which identifies the allocated positioning resources.

[0112] In Phase 7, the serving base station 602-1 sends an RRC reconfiguration message to the initiating UE 604-1 to configure the initiating UE 604-1 for positioning signal transmission and reception. The RRC reconfiguration message identifies the radio resources for the initiating UE 604-1 to send positioning signals to the target UE 604-2, the information for the initiating UE 604-1 to detect positioning signals from the target UE 604-2, and the auxiliary information for the initiating UE 604-1 to calculate the UE-UE position estimate. In Phase 8, the initiating UE 604-1 sends an RRC reconfiguration complete message to the serving base station 602-1. After Phase 7, the two UEs 604 can exchange positioning signals, and in Phase 9, the initiating UE 604-1 performs UE-UE position calculation (e.g., as described above with reference to Figure 4 and 5 ).

[0113] Note that only one of UEs 604-1 and 604-2 may need to transmit a positioning signal, as indicated by the dashed line of the positioning signal transmitted by initiating UE 604-1. Additionally, although only one target UE 604-2 is shown, any number of other target UEs 604-2 may exist. Further, although target UE 604-2 is shown as being served by neighboring base station 602-2, it may be served by serving base station 602-1.

[0114] Figure 7 Call flow 700 of an exemplary base station-assisted UE-UE positioning procedure in accordance with aspects of the present disclosure is illustrated. In Figure 7 the example, initiating UE 704-1 (e.g., any UE described herein) does not have the identifier (ID) of target UE 704-2 (e.g., any other UE described herein) to be included in the positioning request.

[0115] In stage 1, initiating UE 704-1 (labeled "UE1") requests UE-UE positioning with target UE 704-2 (labeled "UE2") by sending an LPP message to LMF 770. The positioning request does not include the identifier of target UE 604-2. Thus, in stage 2, LMF 770 requests serving base station 702-1 (labeled "serving gNB of UE1") to configure radio resources for UE-UE positioning and additionally indicates the identifier(s) of any neighboring UE(s) Figure 7 (target UE 704-2 in the example of ). The identifier(s) should be an identifier that includes or indicates the cell identifier and / or base station identifier of target UE 704-2. Otherwise, LMF 770 shall explicitly indicate the cell identifier and base station identifier. The request between LMF 770 and serving base station 702-1 may be sent on LPPa or NRPPa signaling (as shown).

[0116] Based on the cell identifier and / or base station identifier, serving base station 702-1 may identify neighboring base station 702-2 serving target UE 704-2. Thus, in stages 3 and 4, since target UE 704-2 is served by neighboring base station 702-2 (labeled "gNB2"), serving base station 702-1 sends a UE-UE positioning configuration request to neighboring base station 702-2. Neighboring base station 702-2 configures positioning resources for target UE 704-2 and sends the positioning configuration to serving base station 702-1.

[0117] In phase 5, serving base station 702-1 sends a UE-UE positioning resource response to LMF 770, which identifies the positioning resources that have been allocated by serving base station 702-1 and neighboring base station 702-2. In phase 6, LMF 770 sends an LPP response to serving base station 702-1 for forwarding to initiating UE 704-1, which identifies the allocated positioning resources.

[0118] In phase 7, serving base station 702-1 sends an RRC reconfiguration message to initiating UE 704-1 to configure initiating UE 704-1 for positioning signal transmission and reception. The RRC reconfiguration message identifies the radio resources for initiating UE 704-1 to send a positioning signal to target UE 704-2, the information for initiating UE 704-1 to detect a positioning signal from target UE 704-2, and the assistance information for initiating UE 704-1 to calculate the UE-UE position estimate. In phase 8, initiating UE 704-1 sends an RRC reconfiguration complete message to serving base station 702-1. After phase 7, the two UEs 704 are able to exchange positioning signals, and in phase 9, initiating UE 704-1 performs UE-UE position calculation (e.g., as described above with reference to Figure 4 and 5 .

[0119] Note that only one of UEs 704-1 and 704-2 may need to transmit a positioning signal, as indicated by the dashed line of the positioning signal transmitted by initiating UE 704-1. Additionally, although only one target UE 704-2 is shown, any number of other target UEs 704-2 may exist. Furthermore, although target UE 704-2 is shown as being served by neighboring base station 702-2, it may be served by serving base station 702-1.

[0120] In some cases, a UE may need to request a measurement gap for UE-UE positioning. A measurement gap is a configured time period during which the serving cell suppresses transmissions to the UE so that the UE can receive transmissions (e.g., downlink or sidelink reference signals) from other entities such as other cells or other UEs. The transmissions from other entities may or may not be on the same frequency as the serving cell. In addition to downlink or sidelink reception, the measurement gap can also be used for uplink or sidelink transmissions, including uplink reference signals (such as SRS) or sidelink positioning signals.

[0121] Thus, for UE-UE positioning, the initiating UE may request a measurement gap in order to receive positioning signals from the target UE(s) and / or transmit positioning signals to the target UE(s). The UE may send an RRC message (e.g., UEAssistanceInformation) to the serving base station to request a measurement gap for UE-UE positioning. When approved, the serving base station may configure the UE to send and / or receive positioning signals during the configured gap(s).

[0122] There are different options for which entity performs the positioning calculation. The first option is for the UE to perform the calculation. This option is illustrated in Figure 6 and 7 . As a second option, a location server (e.g., location server 230, LMF 270, SLP 272) performs the calculation. In this option, the initiating UE sends measurements of the received positioning signals and other relevant information to the location server. Similarly, the target UE(s) also report any measurements of the positioning signals from the initiating UE to the location server. The serving base station of the initiating UE may also report its measurements of any positioning signals to the location server. Based on this information, the location server may calculate the relative UE-UE position for the UEs involved and send the calculation result to the initiating UE via LPP signaling.

[0123] The location server may send positioning reports on demand or periodically. Alternatively, the location server may send positioning reports in response to certain events ("event-based"). For example, in the case where the UEs involved are V-UEs and the distance between them is less than a threshold (indicating the likelihood of a collision), the location server may send a positioning report to the two V-UEs to warn them of the likelihood of a collision. Although there are use cases where the location server calculates UE-UE positioning, it is faster for the UEs involved to calculate UE-UE positioning due to, for example, the latency of LPP communication with the location server.

[0124] However, in some cases, this latency can be reduced by locating the location server within the RAN, such as at the serving base station or the base station central unit (CU). When located at the serving base station or CU, the location server is sometimes referred to as a location management component (LMC). The CU is a logical node in the 5G RAN that includes gNB functions (such as transmission of user data, mobility control, radio access network (RAN) sharing, positioning, session management, etc., except for those functions not exclusively assigned to the DU). The CU controls the operation of one or more DUs over the fronthaul (Fs) interface. The DU is a logical node that includes a subset of gNB functions, depending on the functional split between the CU and the DU. Its operation is controlled by the CU.

[0125] By using a location server at the base station or CU, the signaling between the UE and the location server can be simplified. For example, NRPPa is implemented inside the base station. When the location server is integrated into the base station or CU, the NRPPa functionality will be integrated into the F1 Application Protocol (F1AP) interface. The F1 interface provides a means for interconnecting the gNB-CU and gNB-DU of the gNB within the NG-RAN. The F1AP interface is defined in 3GPP Technical Specification (TS) 38.473, which is publicly available and incorporated herein by reference in its entirety.

[0126] When the location server is located in the RAN, the LPP signaling between the UE and the location server can be replaced by a new RRC message between the UE and the serving base station. The RRC message should be protected by security (such as by transmitting these RRC messages on Signaling Radio Bearer 1 (SRB1) and / or Signaling Radio Bearer 2 (SRB2)). Signaling radio bearers are used for the transfer of RRC and NAS signaling messages. SRB1 is used to transfer RRC messages using the Downlink Control Channel (DCCH). SRB2 is used to transfer RRC messages using the DCCH and encapsulating NAS messages. SRB2 has a lower priority than SRB1 and is configured after security activation.

[0127] Alternatively, to minimize UE impact, the LPP message can still be carried on the RRC signaling. However, in this case, NAS layer encryption should not be used for the LPP message. In this way, the base station should be able to decode the LPP message from the NAS layer via RRC.

[0128] Now referring to the base station-assisted data for UE-UE positioning measurements, the base station or location server can directly calculate the UE-UE positioning based on the measurements of the detected positioning signals by the involved UEs. However, the base station can also send the auxiliary data to the UE to enable the UE to calculate the UE-UE positioning. There are two types of auxiliary information, namely, common auxiliary information and UE-specific auxiliary information. The common auxiliary information can be sent in the SIB, Shared Radio Network Temporary Identifier (RNTI), 5G Multicast / Broadcast Service (MBS), or any combination thereof. The UE-specific auxiliary information can be sent by dedicated RRC, PC5 RRC, etc. Note that it is also possible to multicast to the associated UEs via the shared RNTI. The UE-specific auxiliary information may include the base station's measurement of the positioning signal transmitted by the involved UE (which is particularly useful when there is no LOS path between the two UEs), the estimated UE-UE positioning result of the base station, the estimated positions of (other) UEs by the base station, the measured Angle of Arrival (AoA) of the base station, the SSB ID, and / or the Timing Advance (TA) of (other) UEs, or any combination thereof (if available).

[0129] Figure 8 FIG. 800 is a diagram of an exemplary base station-assisted UE-UE positioning procedure between serving base station 802, initiating UE 802-1 (labeled "UE1"), and target UE 802-2 (labeled "UE2"). As Figure 8 explained, each of the initiating UE 802-1 (which may correspond to any UE described herein) and the target UE 802-2 (which may correspond to any other UE described herein) receives and measures (a) positioning signal(s) from another UE 804 (e.g., on a sidelink). UE 804 may measure, for example, the ToA of the respective positioning signal to determine the distance therebetween, as referenced above Figure 4 and 5 described.

[0130] In Figure 8 the example of

[0131] FIG. 800, two UEs 804 are served by the same base station 802 (which may correspond to any base station described herein). The base station 802 detects the (a) positioning signal(s) of each UE 804 and performs positioning measurements (e.g., ToA) on them. The base station 802 may then provide these measurements as assistance information to the initiating UE 804-1 to enable the initiating UE 804-1 to compute UE-UE positioning.

[0132] There are multiple options for UE-UE positioning measurements. For example, there are sidelink-based options, Uu-based options, and radar-based options, WLAN options, options, and laser options. The base station may configure the UE with one or more of these options. For sidelink-based options, the radio resource configuration identifies resources (e.g., time, frequency), sequences to be transmitted, and sequences to be detected / measured. For Uu-based options, the radio resource configuration includes SRS / PTRS configuration, discontinuous reception (DRX) and discontinuous transmission (DTX) configuration, PRS configuration, and SSB-based time windows. The configuration for a UE (whether initiating or target) to transmit a positioning signal (e.g., PRS) includes the following parameters:

[0133] ·PRS-SequenceId (PRS - Sequence Id): This parameter determines the sequence used for PRS. It can be explicitly configured in the RRC and / or MAC control element (MAC - CE), or implicitly configured through any association that may exist between PRS and the physical sidelink shared channel (PSSCH) or channel state information reference signal (CSI - RS) or sub - channels.

[0134] ·PRS-ReOffset (PRS - Resource Element Offset): This parameter defines the starting resource element (RE) offset in the frequency domain of the first symbol within the sidelink PRS resource.

[0135] ·PRS-ResourceSlotOffset (PRS - Resource Slot Offset): This parameter determines the starting slot of the sidelink PRS resource relative to a reference. The reference can be explicitly configured for the UE in the RRC, or can be derived based on the MAC - CE and / or sidelink control information (SCI) message, or can be implicitly determined by any association that may exist between PRS and PSSCH or CSI - RS or sub - channels.

[0136] ·PRS-ResourceSymbolOffset (PRS - Resource Symbol Offset): This parameter determines the starting symbol of the sidelink PRS resource within the starting slot.

[0137] ·PRS-NumSymbols (PRS - Number of Symbols): This parameter defines the number of symbols of the sidelink PRS resource within a slot. In the RRC, multiple such values can be configured, and the final down - selection is done by the MAC - CE or SCI.

[0138] ·PRS-StartPRB (PRS - Starting PRB): This parameter defines the starting physical resource block (PRB) index of the sidelink PRS resource relative to a reference. The reference can be explicitly configured in the RRC / MAC - CE / SCI, or implicitly determined by any association that may exist between PRS and PSSCH or CSI - RS or sub - channels.

[0139] ·PRS-CombSizeN (PRS - Comb Size N): This parameter defines the comb size of the sidelink PRS resource. In the RRC, multiple such values can be configured, and the final down - selection is done by the MAC - CE or SCI.

[0140] ·PRS-MutingPattern (PRS - Muting Pattern): This parameter defines the bit - map of the time positions where the expected PRS resources will not be transmitted.

[0141] · PRS-ResourceRepetitionFactor (PRS - Resource Repetition Factor): This parameter defines how many times each sidelink PRS resource is repeated for a single instance of the downlink PRS resource set.

[0142] · DL-PRS-QCL-Info (DL-PRS-QCL-Information): It can refer to the QCL information (average delay or spatial receive beam) of the sidelink reference signal or the Uu reference signal.

[0143] · PRS-expectedRSTD (PRS-Expected RSTD): This parameter defines the time difference of the received downlink or sidelink subframe timing relative to the expected UE's reception of the sidelink PRS, and

[0144] · PRS-expectedRSTD-uncertainty (PRS-Expected RSTD-Uncertainty), which defines the search window around PRS-expectedRSTD.

[0145] If LPP receives a part of the above PRS configuration, it is not the serving base station but the location server that configures those parameters.

[0146] The configuration for the UE to detect the positioning signal(s) (e.g., PRS) from one or more other UEs includes the same configuration parameters as those shown above. These parameters can be configured (by RRC), activated (by MAC-CE), or triggered (by SCI) to enable the UE to start measurements. Multiple combinations of the parameters {PRS-Sequence Id, PRS-Resource Element Offset, PRS-Resource Slot Offset, PRS-Resource Symbol Offset, PRS-Symbol Number, PRS-Start PRB, PRS-Comb Size N, PRS-Silent Mode, PRS-Resource Repetition Factor} can be configured in RRC, and then the base station can use MAC-CE or SCI to activate or deactivate one or more of those combinations. The parameters {PRS-Subcarrier Spacing (PRS-Subcarrier Spacing), PRS-Cyclic Prefix (PRS-Cyclic Prefix)} can be implicitly determined by the subcarrier spacing (SCS) and cyclic prefix (CP) configured in the sidelink subchannel, unless a sidelink measurement gap is used, in which case these parameters can also be configured by RRC / MAC-CE or SCI.

[0147] As mentioned above, if LPP receives a part of the above PRS configuration, it is not the serving base station but the location server that configures those parameters.

[0148] The radio resources configured by the base station for the UE to detect positioning signals for UE-UE positioning may also include configurations for the UE to detect regular communication signals from other UEs and the base station (e.g., SRS, PSSCH, demodulation reference signals (DMRS) of PSSCH).

[0149] Referring to the radar-based option for radio resource configuration, this can be applied to the use case where the UE is equipped with n radio frequency (RF) front-ends (where n is greater than or equal to '2'). For example, if the UE is equipped with FR1 and FR2 RF front-ends, the UE can camp on FR1, and if the network operator has not deployed FR2, FR2 can be used for UE-UE radar detection.

[0150] For radar detection, there are passive and active modes for echo detection. In passive echo detection, the UE (one or more of the UEs involved) that transmits the positioning signal transmits a radar signal to other UEs and receives the echo reflected from that (those) UE. Active echo detection is similar to an aircraft control tower, where the aircraft receives a ping from the tower and sends back an amplified echo. In this case, the transmitting UE transmits a radar waveform of L (e.g., 10 - 12) bits embedded with the identifier of the transmitting UE. The receiving UE acquires the waveform and sends back a different waveform of L bits embedded with the identifier of this UE.

[0151] In some cases, an OFDM-based waveform can be used as the radar signal. In this case, the signature of L bits can be encoded in the frequency domain of the OFDM resource block (RB). In some cases, a time-domain waveform can be used as the radar signal. In this case, a pulse-modulated time-domain waveform can be used instead of the OFDM-based waveform.

[0152] Other options for radio resource configuration include WLAN configuration, configuration, laser configuration, etc.

[0153] Now referring to the mobility (e.g., handover) procedure for base station-assisted UE-UE positioning, when a UE hands over from one base station to another base station, the UE-UE positioning context should be passed to the target base station. Figure 9 Call flow 900 illustrating an exemplary handover procedure during a base station-assisted UE-UE positioning procedure according to aspects of the present disclosure is shown. In stage 1, the base station 902-1 (labeled "gNB1") of the current serving UE 904 (e.g., any UE described herein) sends a handover request to the target base station 902-2 (labeled "gNB2"). The handover request includes the UE-UE positioning context for the ongoing UE-UE positioning procedure (e.g., the current radio resource configuration, any measurements, etc.).

[0154] In Phase 2, the target base station 902-2 and the LMF 970 perform UE-UE positioning updates to notify the LMF 970 that the target base station 902-2 will be the new serving base station for the UE 904. However, if the UE 904 does not send a UE-UE positioning request to the LMF 970, which means that the LMF 970 is not involved in the UE-UE positioning session, then Phase 2 is not required.

[0155] In Phases 3 and 4, the target base station 902-2 sends a UE-UE positioning request to any participating neighboring base stations 902-3 and receives an acknowledgement response in return. This exchange updates the neighboring base stations 902-3 regarding the change of the serving base station for the UE 904 for the UE-UE positioning session. Note that it is also possible to update the neighboring base stations 902-3 after a handover.

[0156] In Phase 5, the target base station 902-2 sends a handover request acknowledgement (ACK) including a handover command to the current serving base station 902-1. The target base station 902-2 may adjust the radio resource configuration and send new configuration parameters in the handover command. In Phase 6, the current serving base station 902-1 sends a handover command including any updated radio resource configuration parameters to the UE 904. In response, the UE 904 hands over from the base station 902-1 to the target base station 902-2 and continues the UE-UE positioning session.

[0157] Now referring to the UE-UE positioning procedure when the UE is in the RRC inactive mode, after the random access procedure to obtain network access (also known as the (Physical) Random Access Channel ((P)RACH) procedure), the UE is in the RRC connected state. The RRC protocol is used for the air interface between the UE and the base station. In LTE, the UE can be in one of two RRC states (connected or idle), but in NR, the UE can be in one of three RRC states (connected, idle or inactive). Different RRC states have different radio resources associated with these states, and the UE can use these radio resources when in a given state.

[0158] The UE can be transitioned to the RRC Inactive state (e.g., as directed by the serving base station) to achieve power savings. If the UE needs to perform a UE-UE positioning procedure while in the RRC Inactive state, the serving base station can send positioning configuration to the UE in the RRC Release message that transitions the UE to the RRC Inactive state. The RRC Release message can indicate the positioning signals to be sent and the positioning signals to be received (if any) (e.g., including configuration parameters for the positioning signals to be sent and the positioning signals to be received), as well as any auxiliary information for positioning calculations. When a UE-specific configuration update needs to be sent to the UE, the base station can page the UE to bring the UE back to the RRC Connected state. If the UE resumes RRC from a different base station, the UE's context (including the UE-UE positioning context) should be transferred from the previous base station to the new base station.

[0159] Figure 10 An exemplary method 1000 for wireless positioning in accordance with aspects of the present disclosure is illustrated. In one aspect, method 1000 may be performed by a first UE (e.g., any UE described herein).

[0160] At 1010, the first UE transmits a request to perform a UE-UE positioning procedure with a second UE (e.g., any other UE described herein). In one aspect, operation 1010 may be performed by the WWAN transceiver 310, the processing system 332, the memory 340, and / or the positioning component 342, where any or all of the components may be considered as means for performing the operation.

[0161] At 1020, the first UE receives a radio resource configuration for the UE-UE positioning procedure, the radio resource configuration indicating a first radio resource for transmitting a positioning signal to the second UE and a second radio resource for receiving a positioning signal from the second UE. In one aspect, operation 1020 may be performed by the WWAN transceiver 310, the processing system 332, the memory 340, and / or the positioning component 342, where any or all of the components may be considered as means for performing the operation.

[0162] At 1030, the first UE transmits one or more first positioning signals to the second UE on the first radio resource. In one aspect, operation 1030 may be performed by the WWAN transceiver 310, the processing system 332, the memory 340, and / or the positioning component 342, where any or all of the components may be considered as means for performing the operation.

[0163] At 1040, a first UE receives one or more second positioning signals from a second UE on a second radio resource. In one aspect, operation 1040 may be performed by WWAN transceiver 310, processing system 332, memory 340, and / or positioning component 342, and any or all of these components may be considered a means for performing this operation.

[0164] At 1050, the first UE estimates the distance between the first UE and the second UE based at least on the transmission time of the one or more first positioning signals and the ToA of the one or more second positioning signals. In one aspect, operation 1050 may be performed by WWAN transceiver 310, processing system 332, memory 340, and / or positioning component 342, and any or all of these components may be considered a means for performing this operation.

[0165] Figure 11 An exemplary method 1100 for wireless positioning in accordance with aspects of the present disclosure is illustrated. In one aspect, method 1000 may be performed by a first UE (e.g., any UE described herein).

[0166] At 1110, a base station receives a request to allocate radio resources for a UE-UE positioning procedure between a first UE (e.g., any UE described herein) and a second UE (e.g., any other UE described herein). In one aspect, operation 1110 may be performed by WWAN transceiver 350, processing system 384, memory component 386, and / or positioning component 388, and any or all of these components may be considered a means for performing this operation.

[0167] At 1120, the base station transmits a radio resource configuration for the UE-UE positioning procedure to the first UE, the radio resource configuration indicating a first radio resource for transmitting a positioning signal to the second UE and a second radio resource for receiving a positioning signal from the second UE. In one aspect, operation 1110 may be performed by WWAN transceiver 350, processing system 384, memory component 386, and / or positioning component 388, and any or all of these components may be considered a means for performing this operation.

[0168] Those skilled in the art will appreciate that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0169] In addition, those skilled in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithmic steps described in connection with the aspects disclosed herein can be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, the various illustrative components, blocks, modules, circuits, and steps are described above in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

[0170] The various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein can be implemented or performed with a general purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0171] The methods, sequences, and / or algorithms described in connection with the aspects disclosed herein can be embodied directly in hardware, in a software module executed by a processor, or in a combination of both. The software module may reside in RAM, flash memory, ROM, EPROM, EEPROM, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read from, and write to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal (e.g., a UE). In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.

[0172] In one or more exemplary aspects, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted via a computer-readable medium as one or more instructions or code. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed 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 that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc where disks typically 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.

[0173] Although the foregoing disclosure shows illustrative aspects of the present disclosure, it should be noted that various changes and modifications can be made therein without departing from the scope of the present disclosure as defined by the appended claims. The functions, steps, and / or acts in the method claims according to the aspects of the present disclosure described herein need not be performed in any particular order. Moreover, although the elements of the present disclosure may be described or claimed in the singular, the plural is also contemplated unless expressly stated to be limited to the singular.

Claims

1. A method for wireless positioning performed by a first user equipment (UE), comprising: Receiving a notification that a second UE is in proximity to the first UE, the notification including an identifier of the second UE; Transmitting a request to perform a UE-UE positioning procedure with the second UE, the request including the identifier of the second UE; Receiving a radio resource configuration for the UE-UE positioning procedure, the radio resource configuration indicating a first radio resource for transmitting a positioning signal to the second UE and a second radio resource for receiving a positioning signal from the second UE; Transmitting one or more first positioning signals to the second UE on the first radio resource; Receiving one or more second positioning signals from the second UE on the second radio resource; And Estimating a distance between the first UE and the second UE based at least on a transmission time of the one or more first positioning signals and an arrival time (ToA) of the one or more second positioning signals.

2. The method according to claim 1, wherein the first UE has a subscription with a wireless network operator, the subscription permitting the first UE to participate in the UE-UE positioning procedure.

3. The method according to claim 1, further comprising: Transmitting a type of the first UE in non-access stratum (NAS) signaling during network registration.

4. The method according to claim 1, wherein: The first UE receives the notification via unicast; or The first UE receives the notification via broadcast or multicast signaling to at least the first UE and the second UE.

5. The method according to claim 1, wherein the second UE is determined to be in proximity to the first UE based on: The first UE and the second UE are served by the same cell, The first UE and the second UE are served by different cells supported by the same network entity, or The first UE and the second UE are served by different network entities within a threshold distance of each other, wherein the threshold distance is such that it is expected that the first UE and the second UE are within each other's sidelink communication range.

6. The method according to claim 1, wherein the first UE sends the request to a location server in one or more Long Term Evolution (LTE) Positioning Protocol (LPP) messages.

7. The method according to claim 1, wherein the first UE receives the radio resource configuration from a serving network entity.

8. The method according to claim 7, further comprising: Transmitting a request for a measurement gap for the UE-UE positioning procedure to the serving network entity, wherein the radio resource configuration includes one or more measurement gaps in which to transmit the one or more first positioning signals, receive the one or more second positioning signals, or both.

9. The method according to claim 1, wherein the estimating includes: Estimating a distance between the first UE and the second UE based at least on a transmission time of the one or more first positioning signals and a ToA of the one or more second positioning signals.

10. The method according to claim 1, wherein the implementation includes: Transmitting the transmission time of at least the one or more first positioning signals and the ToA of the one or more second positioning signals to a location server.

11. The method according to claim 10, wherein the location server is associated with a serving network entity.

12. The method according to claim 11, wherein the first UE transmits the transmission time of at least the one or more first positioning signals and the ToA of the one or more second positioning signals to the serving network entity in radio resource control (RRC) signaling.

13. The method according to claim 11, wherein the first UE transmits the transmission time of at least the one or more first positioning signals and the ToA of the one or more second positioning signals to the serving network entity in unencrypted LPP signaling.

14. The method according to claim 1, further comprising: Receiving assistance information, the assistance information including common assistance information and UE-specific assistance information.

15. The method according to claim 14, wherein the UE-specific assistance information includes: ToA measurements of the one or more first positioning signals, ToA measurements of the one or more second positioning signals, An estimate of the distance between the first UE and the second UE, An estimate of the location of the second UE, An estimate of the angle of arrival (AoA) of the one or more second positioning signals, A synchronization signal block (SSB) identifier associated with the second UE, A timing advance associated with the second UE, or Any combination thereof.

16. The method according to claim 14, wherein the first UE receives the UE-specific assistance information via RRC signaling or PC5 RRC signaling.

17. The method according to claim 14, wherein the first UE receives the common assistance information in one or more system information blocks (SIBs) or a shared radio network temporary identifier (RNTI).

18. The method according to claim 1, wherein the first radio resource for transmitting positioning signals to the second UE and the second radio resource for receiving positioning signals from the second UE include: Sidelink resources, Uu interface resources, Radar resources, Wireless local area network (WLAN) resources, resources Laser resources, or Any combination thereof.

19. The method according to claim 18, wherein the sidelink resources include: Time domain resources, Frequency domain resources, Sequences of the one or more first positioning signals, Sequences of the one or more second positioning signals, or Any combination thereof.

20. The method according to claim 18, wherein the Uu interface resources include: A downlink reference signal configuration for the one or more first positioning signals, An uplink reference signal configuration for the one or more second positioning signals, A discontinuous reception configuration, A discontinuous transmission configuration, An SSB-based time window, or Any combination thereof.

21. The method according to claim 20, wherein: The downlink reference signal configuration includes a positioning reference signal (PRS) configuration, and the uplink reference signal configuration includes a sounding reference signal (SRS) or a phase tracking reference signal (PTRS) configuration.

22. The method according to claim 18, wherein the radar resources include: the frequencies of the one or more first positioning signals, the frequencies of the one or more second positioning signals, the waveform parameters of the one or more first positioning signals, the waveform parameters of the one or more second positioning signals, the time-domain patterns of the one or more first positioning signals, the time-domain patterns of the one or more second positioning signals, or any combination thereof.

23. The method according to claim 22, wherein: the waveform parameters of the one or more first positioning signals define a waveform based on orthogonal frequency division multiplexing (OFDM), and the waveform parameters of the one or more second positioning signals define a waveform based on OFDM.

24. The method according to claim 22, wherein: the time-domain pattern of the one or more first positioning signals defines a pulse-modulated time-domain waveform, and the time-domain pattern of the one or more second positioning signals defines a pulse-modulated time-domain waveform.

25. The method according to claim 1, further comprising: receiving a handover command, the handover command including a second radio resource configuration for the UE-UE positioning procedure, the second radio resource configuration indicating a third radio resource for transmitting a positioning signal to the second UE and a fourth radio resource for receiving a positioning signal from the second UE; transmitting one or more third positioning signals to the second UE on the third radio resource; receiving one or more fourth positioning signals from the second UE on the fourth radio resource; and estimating the distance between the first UE and the second UE based at least on the transmission time of the one or more third positioning signals and the time of arrival (ToA) of the one or more fourth positioning signals.

26. The method according to claim 1, wherein: the first UE is in the RRC inactive mode, and the radio resource configuration is received in an RRC release message.

27. A method for wireless positioning performed by a network entity, comprising: determining that a second user equipment (UE) is in the vicinity of a first UE; transmitting to the first UE a notification that the second UE is in the vicinity of the first UE, the notification including an identifier of the second UE; receiving a request to allocate radio resources for a UE-UE positioning procedure between the first UE and the second UE; and transmitting to the first UE a radio resource configuration for the UE-UE positioning procedure, the radio resource configuration indicating a first radio resource for transmitting a positioning signal to the second UE and a second radio resource for receiving a positioning signal from the second UE.

28. The method according to claim 27, wherein the second UE is determined to be in the vicinity of the first UE based on the following factors: the first UE and the second UE are served by the same cell, The first UE and the second UE are served by different cellular cells supported by the same network entity, or the first UE and the second UE are served by different network entities within a threshold distance of each other, where the threshold distance is such that it is expected that the first UE and the second UE are within each other's sidelink communication range.

29. The method according to claim 27, further comprising: receiving a first indication that the first UE is permitted to participate in the UE-UE positioning procedure; and receiving a second indication of the UE-UE positioning type supported by the first UE.

30. A first user equipment (UE) comprising: a memory; at least one transceiver; and at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor configured to: cause the at least one transceiver to receive a notification that a second UE is in the vicinity of the first UE, the notification including an identifier of the second UE; cause the at least one transceiver to transmit a request to perform a UE-UE positioning procedure with the second UE, the request including the identifier of the second UE; receive, via the at least one transceiver, a radio resource configuration for the UE-UE positioning procedure, the radio resource configuration indicating a first radio resource for transmitting a positioning signal to the second UE and a second radio resource for receiving a positioning signal from the second UE; cause the at least one transceiver to transmit one or more first positioning signals to the second UE on the first radio resource; receive, via the at least one transceiver, one or more second positioning signals from the second UE on the second radio resource; and estimate the distance between the first UE and the second UE based at least on the transmission time of the one or more first positioning signals and the time of arrival (ToA) of the one or more second positioning signals.

31. The first UE according to claim 30, wherein the first UE has a subscription with a wireless network operator, the subscription permitting the first UE to participate in the UE-UE positioning procedure.

32. The first UE according to claim 30, the at least one processor further configured to: cause the at least one transceiver to transmit the type of the first UE in non-access stratum (NAS) signaling during network registration.

33. The first UE according to claim 30, wherein: the first UE receives the notification via unicast; or the first UE receives the notification via broadcast or multicast signaling to at least the first UE and the second UE.

34. The first UE according to claim 30, wherein the second UE is determined to be in the vicinity of the first UE based on: the first UE and the second UE being served by the same cellular cell, the first UE and the second UE being served by different cellular cells supported by the same network entity, or The first UE and the second UE are served by different network entities within a threshold distance from each other, where the threshold distance is such that it is expected that the first UE and the second UE are within each other's sidelink communication range.

35. The first UE according to claim 30, wherein the first UE sends the request to a location server in one or more Long Term Evolution (LTE) Positioning Protocol (LPP) messages.

36. The first UE according to claim 30, wherein the first UE receives the radio resource configuration from a serving network entity.

37. The first UE according to claim 36, wherein the at least one processor is further configured to: Cause the at least one transceiver to transmit a request for a measurement gap for the UE-UE positioning procedure to the serving network entity, wherein the radio resource configuration includes one or more measurement gaps in which to transmit the one or more first positioning signals, receive the one or more second positioning signals, or both.

38. The first UE according to claim 30, wherein the at least one processor is configured to implement including the at least one processor being configured to: Estimate the distance between the first UE and the second UE based at least on the transmission time of the one or more first positioning signals and the Time of Arrival (ToA) of the one or more second positioning signals.

39. The first UE according to claim 30, wherein the at least one processor is configured to implement including the at least one processor being configured to: Transmit to a location server at least the transmission time of the one or more first positioning signals and the ToA of the one or more second positioning signals.

40. The first UE according to claim 39, wherein the location server is associated with a serving network entity.

41. The first UE according to claim 40, wherein the first UE transmits to the serving network entity at least the transmission time of the one or more first positioning signals and the ToA of the one or more second positioning signals in Radio Resource Control (RRC) signaling.

42. The first UE according to claim 40, wherein the first UE transmits to the serving network entity at least the transmission time of the one or more first positioning signals and the ToA of the one or more second positioning signals in unencrypted LPP signaling.

43. The first UE according to claim 30, wherein the at least one processor is further configured to: Cause the at least one transceiver to receive assistance information, the assistance information including common assistance information and UE-specific assistance information.

44. The first UE according to claim 43, wherein the UE-specific assistance information includes: ToA measurements of the one or more first positioning signals, ToA measurements of the one or more second positioning signals, An estimate of the distance between the first UE and the second UE, An estimate of the location of the second UE, An estimate of the Angle of Arrival (AoA) of the one or more second positioning signals The synchronization signal block (SSB) identifier associated with the second UE, the timing advance associated with the second UE, or any combination thereof.

45. The first UE according to claim 43, wherein the first UE receives the UE-specific assistance information via RRC signaling or PC5 RRC signaling.

46. The first UE according to claim 43, wherein the first UE receives the common assistance information in one or more system information blocks (SIBs) or a shared radio network temporary identifier (RNTI).

47. The first UE according to claim 30, wherein the first radio resource for transmitting the positioning signal to the second UE and the second radio resource for receiving the positioning signal from the second UE include: sidelink resources, Uu interface resources, radar resources, wireless local area network (WLAN) resources, resource laser resources, or any combination thereof.

48. The first UE according to claim 47, wherein the sidelink resources include: time domain resources, frequency domain resources, sequences of the one or more first positioning signals, sequences of the one or more second positioning signals, or any combination thereof.

49. The first UE according to claim 47, wherein the Uu interface resources include: a downlink reference signal configuration for the one or more first positioning signals, an uplink reference signal configuration for the one or more second positioning signals, a discontinuous reception configuration, a discontinuous transmission configuration, an SSB-based time window, or any combination thereof.

50. The first UE according to claim 49, wherein: the downlink reference signal configuration includes a positioning reference signal (PRS) configuration, and the uplink reference signal configuration includes a sounding reference signal (SRS) or a phase tracking reference signal (PTRS) configuration.

51. The first UE according to claim 47, wherein the radar resources include: the frequencies of the one or more first positioning signals, the frequencies of the one or more second positioning signals, the waveform parameters of the one or more first positioning signals, the waveform parameters of the one or more second positioning signals, the time domain patterns of the one or more first positioning signals, the time domain patterns of the one or more second positioning signals, or any combination thereof.

52. The first UE according to claim 51, wherein: the waveform parameters of the one or more first positioning signals define an orthogonal frequency division multiplexing (OFDM)-based waveform, and the waveform parameters of the one or more second positioning signals define an OFDM-based waveform.

53. The first UE according to claim 51, wherein: the time domain patterns of the one or more first positioning signals define a pulse-modulated time domain waveform, and the time domain patterns of the one or more second positioning signals define a pulse-modulated time domain waveform.

54. The first UE according to claim 30, the at least one processor is further configured to: Receive a handover command, the handover command including a second radio resource configuration for the UE-UE positioning procedure, the second radio resource configuration indicating a third radio resource for transmitting a positioning signal to the second UE and a fourth radio resource for receiving a positioning signal from the second UE; Transmit one or more third positioning signals to the second UE on the third radio resource; Receive one or more fourth positioning signals from the second UE on the fourth radio resource; And Estimate the distance between the first UE and the second UE based at least on the transmission time of the one or more third positioning signals and the ToA of the one or more fourth positioning signals.

55. The first UE according to claim 30, wherein: The first UE is in the RRC inactive mode, and The radio resource configuration is received in an RRC release message.

56. A network entity, comprising: A memory; At least one transceiver; And At least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor being configured to: Determine that a second user equipment (UE) is in the vicinity of the first UE; Cause the at least one transceiver to transmit a notification to the first UE regarding the proximity of the second UE to the first UE, the notification including an identifier of the second UE; Receive, via the at least one transceiver, a request to allocate radio resources for a UE-UE positioning procedure between the first UE and the second UE; And Cause the at least one transceiver to transmit a radio resource configuration for the UE-UE positioning procedure to the first UE, the radio resource configuration indicating a first radio resource for transmitting a positioning signal to the second UE and a second radio resource for receiving a positioning signal from the second UE.

57. The network entity according to claim 56, wherein the second UE is determined to be in the vicinity of the first UE based on the following factors: The first UE and the second UE are served by the same cell, The first UE and the second UE are served by different cells supported by the same network entity, or The first UE and the second UE are served by different network entities within a threshold distance of each other, where the threshold distance is such that it is expected that the first UE and the second UE are within each other's sidelink communication range.

58. The network entity according to claim 56, the at least one processor being further configured to: Receive a first indication that the first UE is permitted to participate in the UE-UE positioning procedure; and Receive a second indication of the type of UE-UE positioning supported by the first UE.

59. A first user equipment (UE), comprising: Means for receiving a notification regarding the proximity of a second UE to the first UE, the notification including an identifier of the second UE; Means for transmitting a request to perform a UE-UE positioning procedure with a second UE, the request including an identifier of the second UE; Apparatus for receiving radio resource configuration for the UE-UE positioning procedure, the radio resource configuration indicating a first radio resource for transmitting a positioning signal to the second UE and a second radio resource for receiving a positioning signal from the second UE; Apparatus for transmitting one or more first positioning signals to the second UE on the first radio resource; Apparatus for receiving one or more second positioning signals from the second UE on the second radio resource; and Apparatus for estimating a distance between the first UE and the second UE at least based on a transmission time of the one or more first positioning signals and an arrival time (ToA) of the one or more second positioning signals.

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