Group-based positioning design in asynchronous vehicular networks

Abstract

This document discloses some examples of techniques used for locating user equipment (UE) using a Position Reference Signal (PRS). One or more message elements can communicate between the initiating UE and the responding UE. Message elements may include a pre-PRS message, a PRS message, and a post-PRS message. Pre-PRS and post-PRS messages can be transmitted or received using licensed spectrum. PRS messages can be transmitted or received using unlicensed spectrum. Communication between the initiating UE and the responding UE can be initiated by the initiating UE identifying the responding UE from a plurality of UEs based on the responding UE's location attributes. The responding UE's location attributes may include one or more of the responding UE's orientation, speed, location confidence, and location.

Description

[Technical Field]

[0001] This case relates broadly to the field of wireless communications, and more specifically to the use of Position Reference Signals (PRS) to determine the location of User Equipment (UE). [Previous Technology]

[0002] Wireless communication systems or wireless networks are widely deployed to provide various telecommunications services, such as telephone, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiplexing access technologies that support communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiplexing access technologies include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier Frequency Division Multiple Access (SC-FDMA) systems, Time Division Synchronous Code Division Multiple Access (TD-SCDMA) systems, and Long Term Evolution (LTE). LTE / LTE-Advanced is a collection of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile service standard released by the 3rd Generation Partnership Project (3GPP).

[0003] A wireless network may include several base stations (BSs), which can support communication for several user equipments (UEs). User equipments (UEs) can communicate with base stations (BSs) via downlinks and uplinks. A downlink (or forward link) refers to the communication link from the BS to the UE, and an uplink (or reverse link) refers to the communication link from the UE to the BS. A BS may be referred to as a Node B, gNodeB (gNB), Access Point (AP), Radio Headend, Transmit / Receive Point (TRP), New Radio (NR) BS, 5G Node B, etc. [Summary of the Invention]

[0004] Examples of techniques for locating a user equipment (UE) using a Positioning Reference Signal (PRS) can be disclosed. An initiating UE can be configured to send or transmit one or more message units to a group of two or more responding UEs. Message units may include a pre-PRS message, a PRS message, and a post-PRS message. Each of the responding UEs can be configured to send one or more message units to the initiating UE. The pre-PRS message and the post-PRS message can be transmitted using licensed spectrum. The PRS message can be transmitted using unlicensed spectrum. Using unlicensed spectrum allows the UE to access more bandwidth that can help improve positioning accuracy. Communication from the initiating UE to the group of responding UEs can be performed by the initiating UE broadcasting a message with the same payload to the responding UEs in the group of responding UEs. Communication from the responding UEs can be performed by each responding UE in the group of responding UEs broadcasting its message to the initiating UE.

[0005] In some embodiments, an initiating UE is provided for positioning using a PRS. An example method may include the initiating UE sending a pre-positioning reference signal (pre-PRS) message to a group of responding UEs. The initiating UE's pre-PRS message may include one or more characteristics of the transmission of the initiating UE's positioning reference signal (or reference signal). The initiating UE may be configured to determine one or more characteristics of the transmission of the reference signal for each of the responding UEs and may include this information in the initiating UE's pre-PRS message. The initiating UE's pre-PRS message may indicate when each responding UE may send its pre-PRS message to the initiating UE. The same pre-PRS message from the initiating UE may be sent to all responding UEs. The initiating UE may receive each responding UE's pre-PRS message from each responding UE to at least indicate that each responding UE has received the initiating UE's pre-PRS message. Based on receiving each responding UE's pre-PRS message, the initiating UE may use one or more characteristics of the transmission of the initiating UE's PRS to send a PRS message to the group of responding UEs. Based on the transmission of the PRS message by the initiating UE, the initiating UE can receive each responding UE's PRS message from each responding UE according to one or more characteristics of the transmission of each responding UE's PRS message. Based on receiving each responding UE's PRS message, the initiating UE can send a post-PRS message to a group of responding UEs. The post-PRS message of the initiating UE can instruct the initiating UE to receive PRS messages from each responding UE. Based on sending the post-PRS message of the initiating UE to a group of responding UEs, the initiating UE can receive each responding UE's post-PRS message from each responding UE. Each responding UE's post-PRS message may include timing data related to the departure time of the responding UE's PRS message, timing data related to the arrival time of the initiating UE's PRS message at the responding UE, and data related to the responding UE's location at the departure time of the responding UE's PRS message.

[0006] In some configurations, an initiating UE configured with one or more transceivers, memory, and one or more processors can be used to establish communication with a group of responding UEs using PRS. For example, the initiating UE can be configured to identify a group of responding UEs based on the location attributes of the responding UEs, which may include the direction the responding UE is moving, its speed, its location confidence, or its location, or a combination thereof. The initiating UE can be configured to send a pre-PRS message to the group of responding UEs. The pre-PRS message of the initiating UE may include one or more characteristics of the transmission of the initiating UE's PRS. The pre-PRS message of the initiating UE may include one or more characteristics of the transmission of the responding UE's PRS and the PRS ID of each responding UE. The pre-PRS message of the initiating UE may indicate when each responding UE can send its pre-PRS message to the initiating UE. The initiating UE can receive the pre-PRS message of each responding UE from each responding UE, which confirms that the responding UE has received the pre-PRS message of the initiating UE. The respondent UE's pre-PRS message may include information related to the frequency at which the respondent UE can use to send its PRS to the initiating UE. The initiating UE may send its PRS message to the group of respondent UEs using one or more characteristics of its PRS transmission based on receiving the pre-PRS message from each respondent UE. The initiating UE may receive respondent UE PRS messages from each respondent UE based on sending the initiating UE's PRS message, according to one or more characteristics of its PRS transmission. The initiating UE may send a post-PRS message to the group of respondent UEs based on receiving the PRS message from each respondent UE, the post-PRS message indicating at least that the initiating UE received the PRS message from each respondent UE. The responder UE can receive each responder UE's post-PRS message from the responder UE based on the sending of the initiator UE's post-PRS message. Each responder UE's post-PRS message includes timing data related to the departure time of the responder UE's PRS message, timing data related to the arrival time of the initiator UE's PRS message at the responder UE, and data related to the responder UE's location at the departure time of the responder UE's post-PRS message.

[0007] In some configurations, the responder UE can be used to locate the initiating UE using a PRS. The responder UE can be one of a group of two or more responder UEs identified by the initiating UE based on the responder UE's location attributes. The method may further include receiving a pre-PRS message from the initiating UE, the pre-PRS message including one or more characteristics of the initiating UE's PRS transmission, one or more characteristics of the responder UE's PRS transmission, and information about when the responder UE can send its pre-PRS message to the initiating UE. The responder UE can send its pre-PRS message to the initiating UE to confirm that the responder UE has received the initiating UE's pre-PRS message. The responder UE's pre-PRS message may include data related to the frequency at which the responder UE can use to send its PRS to the initiating UE. The responder UE can receive the initiating UE's PRS message from the responder UE based on one or more characteristics of the initiating UE's PRS transmission, according to the responder UE's pre-PRS message. The responding UE can send a PRS message to the initiating UE using one or more features of the responding UE's PRS transmission based on the receipt of the initiating UE's PRS message. The responding UE can receive a subsequent PRS message from the initiating UE based on the sending of the responding UE's PRS message. The subsequent PRS message from the initiating UE can instruct the initiating UE to receive the responding UE's PRS message. The responding UE can send a subsequent PRS message to the initiating UE based on the receipt of the initiating UE's subsequent PRS message. This subsequent PRS message includes timing data related to the departure time of the responding UE's PRS message, timing data related to the arrival time of the initiating UE's PRS message, and the responding UE's location at the departure time of the responding UE's PRS message.

[0008] In some configurations, a responder UE configured with one or more transceivers, memory, and one or more processors can be used to establish communication with an initiating UE using a PRS. For example, the responder UE can be configured to receive a prior PRS message from the initiating UE, the prior PRS message including one or more characteristics of the transmission of the initiating UE's PRS message. The prior PRS message from the initiating UE may also include one or more characteristics of the transmission of the responder UE's PRS message determined by the initiating UE on behalf of the responder UE, and information about when the responder UE can send its prior PRS message to the initiating UE. The responder UE can send its prior PRS message to the initiating UE, acknowledging its receipt of the initiating UE's prior PRS message. The responder UE can then receive the initiating UE's PRS message from the initiating UE based on the sending of its prior PRS message and according to one or more characteristics of the transmission of the initiating UE's PRS message. The responding UE can send a PRS message to the initiating UE using one or more features of the responding UE's PRS message transmission based on the receipt of the initiating UE's PRS message. The responding UE can receive a subsequent PRS message from the initiating UE based on the sending of its PRS message, confirming that the initiating UE has received the responding UE's PRS message. The responding UE can send a subsequent PRS message to the initiating UE based on the receipt of the initiating UE's subsequent PRS message. The responding UE's subsequent PRS message can be configured to include timing data related to the departure time of the responding UE's PRS message, timing data related to the arrival time of the initiating UE's PRS message, and data related to the responding UE's location at the departure time of the responding UE's PRS message.

Implementation Method

[0022] The various aspects of this invention are described more fully below with reference to the accompanying drawings. However, this invention can be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this invention. Rather, these aspects are provided to make this invention detailed and complete, and to fully convey the scope of this invention to those skilled in the art. Based on the teachings herein, those skilled in the art should recognize that the scope of this invention is intended to cover any aspect of this invention disclosed herein, whether implemented independently of or in combination with any other aspect of this invention. For example, any number of aspects set forth herein can be used to implement an apparatus or method of practice. Furthermore, the scope of this invention is intended to cover such apparatus or methods practiced using structures, functions, or structures and functions other than or different from the various aspects of this invention set forth herein. It should be understood that any aspect of this invention disclosed herein can be embodied by one or more elements of the claim.

[0023] For the purpose of describing the innovative nature of this case, the following description pertains to certain implementations. However, those skilled in the art will readily recognize that the teachings herein can be applied in many different ways. The described implementations can be implemented in any device, system, or network capable of transmitting and receiving radio frequency (RF) signals according to any communication standard such as: Institute of Electrical and Electronics Engineers (IEEE) IEEE 802.11 standard (including those identified as Wi-Fi® technology), Bluetooth® standard, Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Global System for Mobile Communications (GSM), GSM / General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), Terrestrial Trunking Radio (TETRA), Wideband CDMA (W-CDMA), Evolved Data Optimization (EV-DO), 1xEV-DO, EV-DO Rev A, EV-DO Rev B. High-speed packet data (HRPD), high-speed packet access (HSPA), high-speed downlink packet access (HSDPA), high-speed uplink packet access (HSUPA), evolved high-speed packet access (HSPA+), Long Term Evolution (LTE), Advanced Mobile Telephone System (AMPS), or other known signals used for communication in wireless, cellular, or Internet of Things (IoT) networks, such as systems utilizing technologies of 3G, 4G, 5G, 6G, or further implementations thereof.

[0024] In some configurations, a Position Reference Signal (PRS) can be used to determine the location of a User Equipment (UE). According to some positioning techniques, a PRS can be exchanged between two UEs; the first UE can send its PRS to the second UE, and then the second UE can send its PRS back to the first UE. The exchange of PRS between the two UEs can occur within a certain time period, minimizing the clock drift error between the two UEs. In some configurations, the PRS can be a pseudo-noise (PN) sequence. The PRS may not have a payload. The transmission duration of the PRS can be very short (e.g., 33 microseconds). A set of PN sequences may be generated and shared among the UEs in the network. The PRS can be identified by its identifier (ID). For example, all UEs in the network can share an organization that generates PN sequences. The organization that generates PN sequences can include a sequence generator configured to generate PN sequences based on a seed. A UE can select a PN sequence from the generated PN sequences and can indicate to other UEs that it can use the selected PN sequence to communicate with other UEs.

[0025] In some configurations, the UE in the network can be configured to broadcast a Basic Security Message (BSM). The BSM broadcast can occur periodically. In some configurations, the BSM may include information indicating whether the UE is capable of performing PRS-based positioning. The BSM may also include information related to the UE's approximate positioning. The UE can be configured with a clock. In some configurations, due to synchronization errors in a positioning accuracy, possibly in nanoseconds, the timing between one UE and another UE may not be perfectly synchronized.

[0026] The initiating UE can be the UE that initiates the location communication period. The responding UE can be the UE that responds to or reacts to the initiating UE. In some cases, the initiating UE can identify multiple responding UEs at least in part based on information included in the responding UE's BSM. For example, the initiating UE can select multiple responding UEs for the UE location communication period.

[0027] In some configurations, a group of UEs can participate in the location communication period. The group of UEs may include an initiating UE and multiple responding UEs. In some configurations, communication between the initiating UE and each of the multiple responding UEs may include a pre-PRS message, a PRS message, and a post-PRS message. The pre-PRS message may be communicated during the pre-PRS phase, the PRS message may be communicated during the PRS phase, and the post-PRS message may be communicated during the post-PRS phase. The combination of the pre-PRS message, the PRS message, and the post-PRS message can be considered as a location signaling unit for communication between the initiating UE and the responding UE. In some configurations, the location communication period may be performed on multiple location signaling units.

[0028] In some embodiments, PRS messages can be transmitted using a large bandwidth to improve ranging. Positioning accuracy can increase with the increase in bandwidth used for PRS messages. Therefore, PRS messages can be transmitted using unlicensed spectrum with a large bandwidth. For example, licensed spectrum can be associated with frequencies used by the radio communication network according to managed communication standards (e.g., 4G, 5G, etc.), and unlicensed spectrum can be associated with frequencies outside the licensed spectrum where LBT communication protocols can be applied. In order to use unlicensed spectrum to transmit PRS messages, the UE may need to perform a Listen-Before-Speak (LBT) procedure to contend for access to the unlicensed electromagnetic spectrum band (e.g., to determine whether a channel in the unlicensed electromagnetic spectrum band is available). In some embodiments, pre-PRS messages and post-PRS messages can be transmitted using licensed spectrum, as it is an efficient means of communication between UEs in a radio network. In some embodiments, the disclosed positioning technology can be applied to communication systems that implement vehicle-to-everything (V2X) standards.

[0029] In some configurations, the location communication period can be initiated by the initiating UE based on the initiating UE's decision that it is unsure whether its location is associated with the location system. For example, the initiating UE may decide that it is completely outside coverage and has no network connection. In some configurations, when the initiating UE needs to determine its location, the initiating UE may select a group of responding UEs from a plurality of nearby UEs based on the location attributes of each of the responding UEs. In some configurations, the location attributes of the responding UEs may include one or more of the following: the responding UE's confident location, the direction the responding UE may be moving, the responding UE's speed, and the responding UE's location.

[0030] In some states, the initiating UE may select and participate in the location communication period with the responding UE based on the responding UE moving in a direction different from the direction the initiating UE is moving. In some states, the responding UE may select based on the responding UE having a higher location confidence than the initiating UE. In some states, for the location communication period, the initiating UE may choose a responding UE moving in a substantially opposite direction instead of a responding UE moving in a substantially similar direction. This may be because when both the initiating UE and the responding UE are moving in the same direction, there may not be much angular change between them. Multiple angular changes between the location of the initiating UE and the location of the responding UE can help determine the location of the initiating UE. In some states, communication between the initiating UE and the responding UE during the location communication period described herein may not include communication to the base station or to the server computing system.

[0031] In some configurations, the initiating UE and the responding UE can use each other to determine their locations. For example, during a location communication, the initiating UE can send a set of timing data related to its departure and arrival times and location to the responding UE, enabling the responding UE to determine its location. Similarly, the responding UE can send another set of timing data related to its departure and arrival times and location to the initiating UE, enabling the initiating UE to determine its location. In some configurations, the responding UE can be configured to send range information relative to the initiating UE to the initiating UE. In some configurations, the initiating UE can be configured to send range information relative to the responding UE to the responding UE. This range information can indicate the approximate distance between the initiating UE and the responding UE.

[0032] As used herein, an "RF signal" includes electromagnetic waves that transmit information spatially between a transmitter (or transmitting device) and a receiver (or receiving device). As used herein, a transmitter may transmit a single "RF signal" or multiple "RF signals" to a receiver. However, due to the propagation characteristics of RF signals via multipath channels, a receiver may receive multiple "RF signals" corresponding to each transmitted RF signal. The same transmitted RF signal on different paths between the transmitter and receiver may be referred to as a "multipath" RF signal.

[0033] Figure 1 is a simplified illustration of a positioning system 100 according to an embodiment, in which the UE 105, location server 160, and / or other elements of the positioning system 100 can use the techniques provided herein for group-based positioning designs in asynchronous vehicle networks. The techniques described herein can be implemented by one or more elements of the positioning system 100. The positioning system 100 may include: UE 105; one or more satellites 110 (also referred to as spacecraft (SV)) for a Global Navigation Satellite System (GNSS) such as Global Positioning System (GPS), GLONASS, Galileo, or BeiDou; base station 120; access point (AP) 130; location server 160; network 170; and external client 180. Generally, the positioning system 100 can estimate the position of the UE 105 based on the known positions of RF signals received and / or transmitted by the UE 105 and other elements that transmit and / or receive RF signals (e.g., GNSS satellite 110, base station 120, AP 130). Additional details regarding specific position estimation techniques will be discussed in more detail with reference to Figure 2.

[0034] It should be noted that Figure 1 provides only a generalized illustration of the various elements, and any or all of them may be used appropriately, and each may be copied if necessary. Specifically, although only one UE 105 is illustrated, it will be understood that many UEs (e.g., hundreds, thousands, millions, etc.) may utilize the positioning system 100. Similarly, the positioning system 100 may include more or fewer base stations 120 and / or APs 130 than illustrated in Figure 1. The connections illustrating the various elements in the positioning system 100 include data and signal transmission connections, which may include additional (intermediate) elements, direct or indirect physical connections and / or wireless connections, and / or additional networks. Furthermore, depending on the desired functionality, these elements may be rearranged, combined, separated, replaced, and / or omitted. In some embodiments, for example, an external client 180 may connect directly to the location server 160. Those skilled in the art will recognize many modifications to the illustrated elements.

[0035] Depending on the desired functionality, network 170 may include any of a wide variety of wireless and / or wired networks. Network 170 may include, for example, any combination of public and / or private networks, local area networks, and / or wide area networks. Furthermore, network 170 may utilize one or more wired and / or wireless communication technologies. In some embodiments, for example, network 170 may include cellular or other mobile networks, wireless local area networks (WLANs), wireless wide area networks (WWANs), and / or the Internet. Examples of network 170 include Long Term Evolution (LTE) wireless networks, fifth-generation (5G) wireless networks (also known as New Radio (NR) wireless networks or 5G NR wireless networks), Wi-Fi WLANs, and the Internet. LTE, 5G, and NR are technologies defined or being defined by the Third Generation Partnership Project (3GPP). Network 170 may also include more than one network and / or more than one network type.

[0036] Base station 120 and access point (AP) 130 are communicatively coupled to network 170. In some embodiments, base station 120s may be owned, maintained, and / or operated by a cellular network provider and may employ any of a variety of wireless technologies, as described below. Depending on the technology of network 170, base station 120 may include Node B, evolved Node B (eNodeB or eNB), base station transceiver (BTS), radio base station (RBS), NR NodeB (gNB), next-generation eNB (ng-eNB), etc. Base station 120, as a gNB or ng-eNB, may be part of a next-generation radio access network (NG-RAN) that can connect to the 5G core network (5GC) in the case that network 170 is a 5G network. For example, AP 130 may include a Wi-Fi AP or a Bluetooth® AP. Therefore, by using the first communication link 133 to access the network 170 via the base station 120, the UE 105 can send and receive information with network-connected devices (such as the location server 160). Additionally or alternatively, because the AP 130 can also be communicatively coupled to the network 170, the UE 105 can use the second communication link 135 to communicate with network-connected and internet-connected devices, including the location server 160.

[0037] As used herein, the term "base station" can generally refer to a single physical transmission point or multiple co-located physical transmission points that may be located at base station 120. A transmit / receive point (TRP) (also referred to as a transmit / receive point) corresponds to this type of transmission point, and the term "TRP" may be used interchangeably herein with the terms "gNB," "ng-eNB," and "base station." In some cases, base station 120 may include multiple TRPs, for example, each TRP being associated with a different antenna or different antenna array for base station 120. A physical transmission point may include the antenna array of base station 120 (e.g., as in the case of a multiple-input multiple-output (MIMO) system and / or a base station employing beamforming). The term "base station" may additionally refer to multiple non-co-located physical transmission points, which may 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 unit (RRH) (a remote base station connected to a serving base station).

[0038] As used herein, the term "cell" can generally refer to a logical communication entity used for communication with base station 120 and can be associated with an identifier (e.g., Entity Cell Identifier (PCID), Virtual Cell Identifier (VCID)) used to distinguish adjacent cells operating via the same or different carriers. In some examples, a carrier can support multiple cells, and different cells can be configured according to different protocol types that can provide access to different types of devices (e.g., Machine Type Communication (MTC), Narrowband Internet of Things (NB-IoT), Enhanced Mobile Broadband (eMBB), or others). In some cases, the term "cell" can refer to a portion of the geographic coverage area (e.g., a sector) on which a logical entity operates.

[0039] The location server 160 may include a server and / or other computing device configured to determine the estimated location of the UE 105 and / or provide data (e.g., "auxiliary data") to the UE 105 to facilitate location measurement and / or location determination by the UE 105. According to some embodiments, the location server 160 may include a Home Safe User Plane Location (SUPL) location platform (H-SLP) that can support SUPL User Plane (UP) location solutions defined by the Open Mobile Alliance (OMA) and can support location services for the UE 105 based on subscription information for the UE 105 stored in the location server 160. In some embodiments, the location server 160 may include an Exploratory SLP (D-SLP) or an Emergency SLP (E-SLP). The location server 160 may also include an Enhanced Service Mobile Location Center (E-SMLC) that supports the location of the UE 105 using a Control Plane (CP) location solution for UE 105 LTE radio access. The location server 160 may also include a location management function (LMF) that supports the UE 105 using a control plane (CP) location solution for UE 105 NR or LTE radio access.

[0040] In the CP location solution, the signal transmission for controlling and managing the location of UE 105 can use existing network interfaces and protocols and is exchanged between components of network 170 and with UE 105 as a signal transmission from the perspective of network 170. In the UP location solution, the signal transmission for controlling and managing the location of UE 105 can be exchanged between location server 160 and UE 105 as data transmitted from the perspective of network 170 (e.g., data transmitted using Internet Protocol (IP) and / or Transmission Control Protocol (TCP)).

[0041] As previously noted (and discussed in more detail below), the estimated position of UE 105 may be based on measurements of RF signals emitted and / or received by UE 105. In particular, these measurements may provide information about the relative distance and / or angle between UE 105 and one or more elements in positioning system 100 (e.g., GNSS satellite 110, AP 130, base station 120). The estimated position of UE 105 may be estimated geometrically (e.g., using multiangulation and / or multilateration) based on distance and / or angle measurements together with the known positions of one or more elements.

[0042] Although ground elements such as AP 130 and base station 120 may be fixed, the embodiments are not limited thereto. Mobile elements may be used. For example, in some embodiments, the location of UE 105 may be estimated at least in part based on measurements of RF signals 140 communicating between UE 105 and one or more other UEs 145 (which may be mobile or fixed). When one or more other UEs 145 are used in the location determination of a particular UE 105, the UE 105 for which the location is determined may be referred to as the "target UE," and each of the one or more other UEs 145 used may be referred to as the "anchor UE." For the location determination of the target UE, the corresponding location of the one or more anchor UEs may be known and / or determined jointly with the target UE. Direct communication between one or more other UEs 145 and UE 105 may include sidelinks and / or similar device-to-device (D2D) communication technologies. Sidelinks as defined by 3GPP are in the form of D2D communication under cellular-based LTE and NR standards.

[0043] The estimated location of UE 105 can be used in a variety of applications, such as to assist the user of UE 105 in finding direction or navigation, or to assist another user (e.g., associated with an external client 180) in locating UE 105. "Location" is also referred to herein as "location estimation," "estimated location," "location," "positioning," "location estimation," "location pinpoint," "estimated positioning," "location pinpoint," or "pinpoint." The procedure for determining location may be referred to as "positioning," "location determination," "location determination," etc. The location of UE 105 may include the absolute location of UE 105 (e.g., longitude and latitude and possible altitude) or the relative location of UE 105 (e.g., distances to north or south, east or west and possible locations above or below some other known fixed location or other location, such as the location of UE 105 at some known previous time). A location can be specified as a geodesic location comprising multiple coordinates, which can be absolute (e.g., latitude, longitude, and optional altitude), relative (e.g., relative to a known absolute location), or local (e.g., X, Y, and optional Z coordinates according to a coordinate system defined relative to a local area, such as a factory, warehouse, university campus, shopping mall, stadium, or conference center). Alternatively, a location can be a city location and can then include one or more of the following: street address (e.g., including country, state, county, city, road and / or street name or label and / or road number or street number) and / or place, building, part of a building, floor of a building, and / or room within a building. A location can also include indications of uncertainty or error, such as by way of the expected error in horizontal and vertical distances to the location, or an indication of the area or volume (e.g., a circle or ellipse) within which UE 105 is expected to be located with a certain level of confidence (e.g., 95% confidence).

[0044] External client 180 may be a web server or remote application that may have some association with UE 105 (e.g., accessible by a user of UE 105), or it may be a server, application, or computer system that provides location services to one or more other users (this may include obtaining and providing the location of UE 105 (e.g., to enable services such as finding relatives or friends, or the location of children or pets)). Additionally or alternatively, external client 180 may obtain the location of UE 105 and provide it to emergency service providers, government agencies, etc.

[0045] As previously noted, the example positioning system 100 can be implemented using a wireless communication network (such as an LTE-based or 5G NR-based network). Figure 2 illustrates a diagram of a 5G NR positioning system 200, illustrating an embodiment of a 5G NR positioning system (e.g., positioning system 100). The 5G NR positioning system 200 can be configured to use access nodes 210, 214, 216 (which may correspond to base station 120 and access point 130 of Figure 1) and optionally, an LMF 220 (which may correspond to location server 160) to implement one or more positioning methods to determine the location of UE 105. Here, the 5G NR positioning system 200 includes UE 105 and elements of a 5G NR network, which includes a next-generation (NG) radio access network (RAN) (NG-RAN) 235 and a 5G core network (5G CN) 240. The 5G network may also be referred to as an NR network; NG-RAN 235 may be referred to as a 5G RAN or NR RAN; and 5G CN 240 may be referred to as an NG core network (NGC). The 5G NR positioning system 200 may further utilize information from GNSS satellites 110 belonging to a GNSS system, such as the Global Positioning System (GPS) or similar systems (e.g., GLONASS, Galileo, BeiDou, Indian Regional Navigation Satellite System (IRNSS)). Additional elements of the 5G NR positioning system 200 are described below. The 5G NR positioning system 200 may include additional or alternative elements.

[0046] It should be noted that Figure 2 provides only a generalized illustration of the various components, and any or all of them may be used appropriately, and each may be copied or omitted as necessary. Specifically, although only one UE 105 is illustrated, it will be understood that many UEs (e.g., hundreds, thousands, millions, etc.) may still utilize the 5G NR positioning system 200. Similarly, the 5G NR positioning system 200 may include more (or fewer) numbers of GNSS satellites 110, gNB 210, ng-eNB 214, wireless local area network (WLAN) 216, access and mobility management function (AMF) 215, external client 230, and / or other components. The connections illustrating the various components in the 5G NR positioning system 200 include data and signal transmission connections, which may include additional (intermediate) components, direct or indirect physical connections and / or wireless connections, and / or additional networks. Furthermore, depending on the desired functionality, these components may be rearranged, combined, separated, replaced, and / or omitted.

[0047] UE 105 may include and / or be referred to as a device, mobile device, wireless device, mobile terminal, terminal, mobile station (MS), Secure User Plane Location (SUPL) enabled terminal (SET), or some other name. Furthermore, UE 105 may correspond to a mobile phone, smartphone, laptop, tablet, personal data assistant (PDA), navigation device, Internet of Things (IoT) device, or some other portable or mobile device. Typically, although not essential, UE 105 may support wireless communications using one or more Radio Access Technologies (RATs), such as GSM, CDMA, W-CDMA, LTE, High Rate Packet Data (HRPD), IEEE 802.11 Wi-Fi®, Bluetooth, Global Interoperability Microwave Access (WiMAX™), 5G NR (e.g., using NG-RAN 235 and 5G CN 240), etc. UE 105 may also support wireless communication using WLAN 216, which (such as one or more RATs, and as previously indicated relative to Figure 1) can connect to other networks, such as the Internet. The use of one or more of these RATs may allow UE 105 to communicate with external client 230 (e.g., via elements of 5G CN 240 not shown in Figure 2 or possibly via Gateway Mobile Location Center (GMLC) 225), and / or allow external client 230 to receive location information about UE 105 (e.g., via GMLC 225). External client 230 of Figure 2 may correspond to external client 180 of Figure 1, as implemented or communicatively coupled to in a 5G NR network.

[0048] UE 105 may include a single entity or may include multiple entities, such as entities in a personal area network (PAN), in which the user may employ audio, video, and / or data I / O devices and / or body sensors, as well as separate wired or wireless modems. The estimation of the location of UE 105 may be referred to as location, location estimate, location pinpoint, pinpoint, location, location estimate, or location pinpoint, and may be geodesic, thereby providing UE 105 with location coordinates (e.g., latitude and longitude), which may or may not include an altitude component (e.g., altitude above sea level, altitude above or below ground level, floor level, or basement level). Alternatively, the location of UE 105 may be represented as a city location (e.g., a postal address or a specific point or small area within a building, such as a particular room or floor). The location of UE 105 may also be represented as an area or volume (geodetic or defined in a city-like form) in which UE 105 is expected to be located with a certain probability or confidence level (e.g., 67%, 95%, etc.). The location of UE 105 can also be a relative location, including, for example, distance and direction defined relative to an origin at a known location, or relative X, Y (and Z) coordinates, which can be defined geodeticly, in urban terms, or by a point, area, or volume indicated on a reference map, floor plan, or building plan. In the description contained herein, unless otherwise stated, the use of the term "location" can include any of these variations. When calculating the location of the UE, the local X, Y, and possibly Z coordinates are typically solved, and then, if necessary, the local coordinates are converted to absolute coordinates (e.g., for latitude, longitude, and altitude above or below mean sea level).

[0049] The base stations in the NG-RAN 235 shown in Figure 2 may correspond to base station 120 in Figure 1 and may include NR NodeBs (gNBs) 210-1 and 210-2 (collectively and generally referred to herein as gNB 210). Pairs of gNBs 210 in the NG-RAN 235 may be connected to each other (e.g., directly or indirectly via other gNBs 210 as shown in Figure 2). The communication interface between the base stations (gNBs 210 and / or ng-eNBs 214) may be referred to as the Xn interface 237. Access to the 5G network is provided to UE 105 via radio communication between UE 105 and one or more of the gNBs 210, which may represent UE 105 using 5G NR to provide radio communication access to the 5G CN 240. The radio interface between the base station (gNB 210 and / or ng-eNB 214) and UE 105 can be referred to as Uu interface 239. 5G NR radio access can also be referred to as NR radio access or 5G radio access. In Figure 2, it is assumed that the serving gNB for UE 105 is gNB 210-1, but if UE 105 moves to another location, other gNBs (such as gNB 210-2) can also act as serving gNBs, or can act as secondary gNBs to provide additional throughput and bandwidth to UE 105.

[0050] The base stations in the NG-RAN 235 shown in Figure 2 may also, or alternatively, include a next-generation evolved Node B, also referred to as an ng-eNB 214. The ng-eNB 214 may connect to one or more gNBs 210 in the NG-RAN 235, for example, directly or indirectly via other gNBs 210 and / or other ng-eNBs. The ng-eNB 214 may provide LTE radio access and / or evolved LTE (eLTE) radio access to the UE 105. Some of the gNBs 210 in Figure 2 (e.g., gNB 210-2) and / or the ng-eNB 214 may be configured to act as location-only beacons, which may transmit signals (e.g., a location reference signal (PRS)) and / or broadcast auxiliary data to assist the UE 105 in positioning, but may not receive signals from the UE 105 or from other UEs. Note that although only one ng-eNB 214 is illustrated in Figure 2, some embodiments may include multiple ng-eNBs 214. Base stations 210 and 214 can communicate directly with each other via the Xn communication interface. Additionally or alternatively, base stations 210 and 214 can communicate directly or indirectly with other components of the 5G NR positioning system 200, such as LMF 220 and AMF 215.

[0051] The 5G NR positioning system 200 may also include one or more WLANs 216, which can connect to non-3GPP interoperability functions (N3IWF) 250 in the 5G CN 240 (e.g., in the case of untrusted WLANs 216). For example, the WLAN 216 may support IEEE 802.11 Wi-Fi access for UE 105 and may include one or more Wi-Fi APs (e.g., AP 130 in Figure 1). Here, the N3IWF 250 may connect to other components in the 5G CN 240, such as AMF 215. In some embodiments, the WLAN 216 may support another RAT, such as Bluetooth. The N3IWF 250 can provide secure access for UE 105 to other components in the 5G CN 240, and / or can support interoperability between one or more protocols used by WLAN 216 and UE 105 and one or more protocols used by other components of the 5G CN 240 (such as AMF 215). For example, the N3IWF 250 can support establishing an IPSec tunnel with UE 105, terminating the IKEv2 / IPSec protocol with UE 105, terminating the control plane and user plane to the N2 and N3 interfaces of the 5G CN 240 respectively, and relaying uplink (UL) and downlink (DL) control plane non-access layer (NAS) signal transmission between UE 105 and AMF 215 on the N1 interface. In some other embodiments, WLAN 216 may connect directly to elements within 5G CN 240 (e.g., AMF 215 as shown by the dashed line in FIG. 2) without via N3IWF 250. For example, if WLAN 216 is a trusted WLAN of 5G CN 240, a direct connection between WLAN 216 and 5G CN 240 may occur, and this direct connection may be enabled using a Trusted WLAN Interoperability Function (TWIF) (not shown in FIG. 2), which may be an element within WLAN 216. Note that although only one WLAN 216 is illustrated in FIG. 2, some embodiments may include multiple WLANs 216.

[0052] The access node may include any of a variety of network entities that enable communication between UE 105 and AMF 215. This may include gNB 210, ng-eNB 214, WLAN 216 and / or other types of cellular base stations. However, the access node providing the functionality described herein may additionally or alternatively include entities that enable communication to any of the various RATs not illustrated in FIG. 2, which may include non-cellular technologies. Therefore, the term "access node" as used in the embodiments described herein below may include, but is not necessarily limited to, gNB 210, ng-eNB 214 or WLAN 216.

[0053] In some embodiments, access nodes such as gNB 210, ng-eNB 214 or WLAN 216 (alone or in combination with other elements of the 5G NR positioning system 200) may be configured to obtain location measurements of uplink (UL) signals received from UE 105 in response to a request for location information received from LMF 220 and / or obtain downlink (DL) location measurements obtained by UE 105 for DL ​​signals received by UE 105 from one or more access nodes. As noted, although Figure 2 illustrates access nodes 210, 214, and 216 configured to communicate according to 5G NR, LTE, and Wi-Fi protocols respectively, access nodes configured to communicate according to other protocols can be used, such as, for example, a Node B using the Wideband Code Division Multiplexing (WCDMA) protocol for Universal Mobile Telecommunications Services (UMTS) Terrestrial Radio Access Network (UTRAN), an eNB using the LTE protocol for Evolved UTRAN (E-UTRAN), or a Bluetooth® beacon using the Bluetooth protocol for WLAN. For example, in a 4G Evolved Packet System (EPS) providing LTE radio access to UE 105, the RAN may include an E-UTRAN, which may include base stations including eNBs supporting LTE radio access. The core network for the EPS may include an Evolved Packet Core (EPC). Then, EPS can include E-UTRAN plus EPC, where E-UTRAN corresponds to NG-RAN 235 and EPC corresponds to 5GCN 240 in Figure 2. The methods and techniques described herein for obtaining the city location of UE 105 can be applied to other such networks.

[0054] gNB 210 and ng-eNB 214 can communicate with AMF 215, which communicates with LMF 220 for positioning functionality. AMF 215 can support the mobility of UE 105, including cell changes and handovers from access nodes 210, 214, or 216 of the first RAT to access nodes 210, 214, or 216 of the second RAT. AMF 215 can also participate in supporting signaling connections to UE 105 and, possibly, data and voice bearers for UE 105. When UE 105 accesses NG-RAN 235 or WLAN 216, LMF 220 can support positioning of UE 105 using the CP location solution, and can support positioning procedures and methods, including UE-assisted / UE-based and / or network-based procedures / methods, such as Assisted GNSS (A-GNSS), Observed Time Difference of Arrival (OTDOA) (which may be called Time Difference of Arrival (TDOA) in NR), Real-Time Kinematics (RTK), Precise Point Positioning (PPP), Differential GNSS (DDNSS), Enhanced Cell ID (ECID), Angle of Arrival (AOA), Angle of Departure (AOD), WLAN positioning, Round-Trip Propagation Delay (RTT), Multi-Cell RTT, and / or other positioning procedures and methods. LMF 220 can also process location service requests for UE 105 received, for example, from AMF 215 or GMLC 225. LMF 220 can connect to AMF 215 and / or GMLC 225. In some embodiments, networks such as 5GCN 240 may additionally or alternatively implement other types of location support modules, such as Enhanced Services Mobile Location Center (E-SMLC) or SUPL Location Platform (SLP). Note that in some embodiments, at least a portion of the location functionality (including the determination of the location of UE 105) may be performed at UE 105 (e.g., by measuring downlink PRS (DL-PRS) signals transmitted by radio nodes such as gNB 210, ng-eNB 214 and / or WLAN 216, and / or using auxiliary data provided to UE 105, for example, by LMF 220).

[0055] The Gateway Mobile Location Center (GMLC) 225 can support location requests for UE 105 received from the external client 230, and can forward this location request to the AMF 215 for forwarding to the LMF 220. The location response from the LMF 220 (e.g., containing a location estimate for UE 105) can similarly be returned to the GMLC 225 directly or via the AMF 215, and the GMLC 225 can then return the location response (e.g., containing a location estimate) to the external client 230.

[0056] Network Exposure Function (NEF) 245 can be included in 5GCN 240. NEF 245 can support the secure exposure of capabilities and events related to 5GCN 240 and UE 105 to external client 230, which can be referred to as Access Function (AF), and can enable the secure provision of information from external client 230 to 5GCN 240. For the purpose of obtaining the location of UE 105 (e.g., city location) and providing that location to external client 230, NEF 245 can be connected to AMF 215 and / or GMLC 225.

[0057] As further illustrated in Figure 2, the LMF 220 can communicate with the gNB 210 and / or ng-eNB 214 using the NR Positioning Protocol Annex (NRPPa) as defined in 3GPP Technical Specification (TS) 38.445. NRPPa messages can be transmitted between the gNB 210 and the LMF 220, and / or between the ng-eNB 214 and the LMF 220 via the AMF 215. As further illustrated in Figure 2, the LMF 220 and UE 105 can communicate using the LTE Positioning Protocol (LPP) as defined in 3GPP TS 37.355. Here, LPP messages can be transmitted between UE 105 and the LMF 220 via the AMF 215 and the serving gNB 210-1 or serving ng-eNB 214 for UE 105. For example, LPP messages can be transmitted between LMF 220 and AMF 215 using messages for service-based operations (e.g., based on Hypertext Transfer Protocol (HTTP)), and between AMF 215 and UE 105 using the 5G NAS protocol. The LPP protocol can be used to support the location of UE 105 using UE-assisted and / or UE-based positioning methods (such as A-GNSS, RTK, TDOA, multi-cell RTT, AOD, and / or ECID). The NRPPa protocol can be used to support the location of UE 105 using network-based positioning methods (such as ECID, AOA, uplink TDOA (UL-TDOA)), and / or can be used by LMF 220 to obtain location-related information from gNB 210 and / or ng-eNB 214, such as parameters defining DL-PRS transmissions from gNB 210 and / or ng-eNB 214.

[0058] When UE 105 accesses WLAN 216, LMF 220 can use NRPPa and / or LPP to obtain the location of UE 105 in a manner similar to that described above when UE 105 accesses gNB 210 or ng-eNB 214. Therefore, NRPPa messages can be transmitted between WLAN 216 and LMF 220 via AMF 215 and N3IWF 250 to support network-based positioning of UE 105 and / or transmission of other location information from WLAN 216 to LMF 220. Alternatively, NRPPa messages can be transmitted between N3IWF 250 and LMF 220 via AMF 215 to support network-based positioning of UE 105 based on location-related information and / or location measurements transmitted from N3IWF 250 to LMF 220 using NRPPa, which is known or accessible to N3IWF 250. Similarly, LPP and / or LPP messages can be transmitted between UE 105 and LMF 220 via AMF 215, N3IWF 250 and the service WLAN 216 for UE 105 to support UE-assisted or UE-based positioning of UE 105 by LMF 220.

[0059] In the 5G NR positioning system 200, the positioning method can be classified as "UE-assisted" or "UE-based". This can depend on where the request to determine the positioning of UE 105 originates. For example, if the request originates from the UE (e.g., from an application or "app" executed by the UE), the positioning method can be classified as UE-based. On the other hand, if the request originates from an external client or other devices or services within the AF 230, LMF 220, or 5G network, the positioning method can be classified as UE-assisted (or "network-based").

[0060] Using a UE-assisted positioning method, UE 105 can obtain a location measurement and transmit the measurement to a location server (e.g., LMF 220) for calculating a location estimate for UE 105. For RAT-related positioning methods, the location measurement may include one or more of the following: Received Signal Strength Indication (RSSI), Round-Trip Time (RTT), Reference Received Power (RSRP), Reference Received Quality (RSRQ), Reference Time Difference (RSTD), Time of Arrival (TOA), AOA, Receive Time-Transmit Time Difference (Rx-Tx), Differential AOA (DAOA), AOD, or Timing Advance (TA) for one or more access points of gNB 210, ng-eNB 214, and / or WLAN 216. Additionally or alternatively, similar measurements may be performed on sidelink signals transmitted by other UEs, which, if their locations are known, may be used as anchor points for the positioning of UE 105. Location measurements may also include, or alternatively include, measurements for RAT-independent positioning methods such as GNSS (e.g., GNSS pseudorange, GNSS code phase, and / or GNSS carrier phase for GNSS satellite 110), WLAN, etc.

[0061] Using a UE-based positioning method, the UE 105 can obtain a location measurement (e.g., which may be the same as or similar to the location measurement of a UE-assisted positioning method), and can also calculate the location of the UE 105 (e.g., as described in the context of auxiliary information received from a location server such as LMF 220 or SLP or broadcast by gNB 210, ng-eNB 214 or WLAN 216).

[0062] Using a network-based positioning method, one or more base stations (e.g., gNB 210 and / or ng-eNB 214), one or more APs (e.g., in WLAN 216) or N3IWF 250 can obtain location measurements (e.g., RSSI, RTT, RSRP, RSRQ, AOA, or TOA) for signals transmitted by UE 105, and / or can receive measurements obtained by UE 105 or, in the case of N3IWF 250, by APs in WLAN 216, and can send these measurements to a location server (e.g., LMF 220) for calculating a location estimate for UE 105.

[0063] Depending on the type of signal used for positioning, the positioning of UE 105 can also be classified as UL-based, DL-based, or DL-UL-based. For example, if positioning is based solely on signals received at UE 105 (e.g., from a base station or other UE), positioning can be classified as DL-based. On the other hand, if positioning is based solely on signals transmitted by UE 105 (e.g., which may be received by a base station or other UE), positioning can be classified as UL-based. DL-UL-based positioning includes positioning based on signals that UE 105 both transmits and receives, such as RTT-based positioning. Sidelink (SL)-assisted positioning includes signals used for communication between UE 105 and one or more other UEs. According to some embodiments, UL, DL, or DL-UL positioning as described herein may be able to use SL signaling as a supplement to or replacement of SL, DL, or DL-UL signaling.

[0064] Depending on the type of positioning (e.g., UL-based, DL-based, or DL-UL-based), the type of reference signal used may differ. For example, for DL-based positioning, these signals may include PRS (e.g., DL-PRS transmitted by the base station or SL-PRS transmitted by other UEs) that can be used for TDOA, AOD, and RTT measurements. Other reference signals that can be used for positioning (UL, DL, or DL-UL) may include: detection reference signals (SRS), channel status information reference signals (CSI-RS), synchronization signals (e.g., synchronization signal block (SSB) synchronization signal (SS)), physical uplink control channel (PUCCH), physical uplink shared channel (PUSCH), physical side uplink shared channel (PSSCH), demodulation reference signals (DMRS), etc. Furthermore, reference signals may be transmitted in the Tx beam and / or received in the Rx beam (e.g., using beamforming techniques), which may affect angle measurements such as AOD and / or AOA.

[0065] Figure 3 is a diagram illustrating an example frame structure for NR and related terms, which can serve as the basis for physical layer communication between UE 105 and a base station (such as serving gNB 210-1). Transmission isochrones for each of the downlink and uplink can be divided into units of radio frames. Each radio frame can have a predetermined duration (e.g., 10 ms) and can be divided into 10 subframes, each 1 ms long, indexed from 0 to 9. Each subframe can include a variable number of time slots, depending on the subcarrier spacing. Each time slot can include a variable number of symbol periods (e.g., 7 or 14 symbols), depending on the subcarrier spacing. The symbol periods in each time slot can be assigned an index. Mini-time slots can include sub-time slot structures (e.g., 2, 3, or 4 symbols). Additionally, Figure 3 illustrates a complete orthogonal frequency division multiplexing (OFDM) of the subframes, illustrating how a subframe can be divided into multiple resource blocks (RBs) in both time and frequency. A single RB can include a grid of resource elements (REs) spanning 14 symbols and 12 subcarriers.

[0066] Each symbol of a time slot can indicate the link direction (e.g., downlink (DL), uplink (UL), or flexible) or data transmission, and the link direction for each subframe can be dynamically switched. The link direction can be based on the time slot format. Each time slot can include DL / UL data and DL / UL control information. In NR, synchronization signal (SS) blocks are transmitted. SS blocks include a primary SS, a secondary SS, and a two-symbol Physical Broadcast Channel (PBCH). SS blocks can be transmitted in fixed time slot positions, such as symbols 0 to 3 as shown in Figure 3. PSS and SSS can be used by the UE for cell search and acquisition. PSS can provide half-frame timing, and SS can provide cyclic prefix (CP) length and frame timing. PSS and SSS can provide cell identification. PBCH carries some basic system information, such as downlink system bandwidth, timing information within the radio frame, periodicity of SS burst sets, system frame number, etc.

[0067] Figure 4 is a diagram illustrating an example of a wireless communication frame sequence 400 with PRS positioning timing. A "PRS instance" or "PRS timing" is an instance of a periodically repeating time window (e.g., a group of one or more consecutive time slots) in which PRS is expected to be transmitted. A PRS timing may also be referred to as a "PRS positioning timing," "PRS positioning instance," "positioning timing," "positioning instance," "positioning repetition," or simply "timing," "instance," or "repetition." The sub-frame sequence 400 can be used for broadcasting PRS signals (DL-PRS signals) from base stations 120 in positioning system 100. The wireless communication frame sequence 400 can be used in 5G NR (e.g., 5G NR positioning system 200) and / or LTE. Similar to Figure 3, in Figure 4, the horizontal direction represents time (e.g., on the X-axis), where time increases from left to right. The vertical direction represents frequency (e.g., on the Y-axis), where frequency increases (or decreases) from bottom to top.

[0068] Figure 4 illustrates how PRS positioning times 410-1, 410-2, and 410-3 (collectively and generally referred to herein as positioning time 410) are determined by the system frame number (SFN), cell-specific subframe offset (ΔPRS) 415, the length or span of the LPRS subframes, and the PRS periodicity (TPRS) 420. The cell-specific PRS subframe configuration can be defined by the "PRS Configuration Index" IPRS included in auxiliary data (e.g., TDOA auxiliary data) that can be defined by the management 3GPP standards. The cell-specific subframe offset (ΔPRS) 415 can be defined based on the number of subframes sent from the start of the first (subsequent) PRS positioning time starting from the system frame number (SFN) 0.

[0069] The PRS can be transmitted by a wireless node (e.g., base station 120) after appropriate configuration (e.g., by an operation and maintenance (O&M) server). The PRS can be transmitted in specific positioning subframes grouped into positioning times 410. For example, PRS positioning times 410-1 can include consecutive positioning subframes of NPRS, where the digit NPRS can be between 1 and 160 (e.g., values ​​1, 2, 4, and 6, as well as other values). PRS times 410 can be grouped into one or more PRS time groups. As noted, PRS positioning times 410 can occur periodically at intervals of milliseconds (or subframes) (represented by digital TPRS), where TPRS can be equal to 5, 10, 20, 40, 80, 160, 320, 640, or 1280 (or any other suitable value). In some cases, TPRS can be measured based on the number of subframes between the start of consecutive positioning times.

[0070] In some configurations, when UE 105 receives the PRS configuration index IPRS in auxiliary data for a specific cell (e.g., base station), UE 105 can use the stored index data to determine the PRS periodicity TPRS 420 and the cell-specific subframe offset (ΔPRS) 415. UE 105 can then determine the radio frames, subframes, and time slots when the PRS is scheduled in the cell. The auxiliary data can be determined by, for example, a location server (e.g., location server 160 in Figure 1 and / or LMF 220 in Figure 2) and includes auxiliary data for a reference cell and the number of neighboring cells supported by various radio nodes.

[0071] Typically, PRS timings from all cells using the same frequency in the network are time-aligned and can have a fixed, known time offset (e.g., cell-specific subframe offset (ΔPRS) 415) relative to other cells using different frequencies in the network. In an SFN synchronous network, all radio nodes (e.g., base station 120) can be aligned on both frame boundaries and system frame numbers. Therefore, in an SFN synchronous network, all cells supported by various radio nodes can use the same PRS configuration index for any specific frequency of PRS transmission. On the other hand, in an SFN asynchronous network, various radio nodes can be aligned on frame boundaries but not on system frame numbers. Therefore, in an SFN asynchronous network, the PRS configuration index for each cell can be configured individually by the network, such that the PRS timings are time-aligned. If UE 105 can obtain the cell timing (e.g., SFN or frame number) of at least one cell (e.g., a reference cell or serving cell), then UE 105 can determine the timing of the PRS timing 410 for the reference cell and neighboring cells used for TDOA positioning. The timing of other cells can then be derived by UE 105 based on the assumption, for example, that PRS timings from different cells overlap.

[0072] Referring to the frame structure in Figure 3, the set of REs used for PRS transmission is called a "PRS resource". The set of resource elements can span multiple RBs in the frequency domain and one or more consecutive symbols within a time slot in the time domain, within which pseudo-random quadrature phase shift keying (QPSK) sequences are transmitted from the antenna port of the TRP. In a given OFDM symbol in the time domain, the PRS resource occupies a consecutive RB in the frequency domain. The transmission of the PRS resource within a given RB has a specific comb size (also called "comb density"). The comb size "N" represents the subcarrier spacing (or frequency / tone spacing) within each symbol of the PRS resource configuration, where the configuration uses every Nth subcarrier of some symbols of the RB. For example, for a 4-comb configuration, for each of the four symbols of the PRS resource configuration, the RE corresponding to every fourth subcarrier (e.g., subcarriers 0, 4, 8) is used to transmit the PRS resource. For example, comb sizes of 2-comb, 4-comb, 6-comb, and 12-comb can be used for PRS. Figure 5 provides examples of different comb sizes used with different numbers of symbols.

[0073] A "PRS resource set" is a group of PRS resources used for the transmission of PRS signals, where each PRS resource has a PRS resource ID. Furthermore, PRS resources in a PRS resource set are associated with the same TRP. A PRS resource set is identified by its PRS resource set ID and associated with a specific TRP (identified by its cell ID). Additionally, PRS resources in a PRS resource set can have the same periodicity, a common silence mode configuration, and the same repetition factor across time slots. The periodicity can have a length selected from 2m∙{4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 160, 320, 640, 1280, 2560, 5120, 10240} time slots, where µ = 0, 1, 2, 3. The repetition factor can have a length selected from {1, 2, 4, 6, 8, 16, 32} time slots.

[0074] A PRS resource ID in a PRS resource set can be associated with a single beam (and / or beam ID) transmitted from a single TRP (where the TRP can transmit one or more beams). That is, each PRS resource in a PRS resource set can be transmitted on a different beam, and therefore a PRS resource (or simply "resource") can also be referred to as a "beam". Note that this has no effect on whether the TRP or the beam on which the PRS is transmitted is known to the UE.

[0075] In the 5G NR positioning system 200 illustrated in Figure 2, TRPs (e.g., 210, 214, 216) can transmit frames or other entity layer signaling sequences supporting PRS signals (i.e., DL-PRS) according to the frame configuration described above. These frames or other entity layer signaling sequences can be measured and used for positioning determination of UE 105. As noted, other types of radio network nodes, including other UEs, can also be configured to transmit PRS signals configured in a manner similar to (or the same as) described above. Because the transmission of PRS by a radio network node can be directed to all UEs within radio range, the radio network node can be considered to be transmitting (or broadcasting) PRS.

[0076] Figure 6 is a timing diagram illustrating two different options for the use of time slots for a resource set according to an embodiment. Since each example repeats each resource four times, the repetition factor of the resource set is said to be four. Continuous sweep 610 includes repeating a single resource (resource 1, resource 2, etc.) four times before proceeding to a subsequent resource. In this example, if each resource corresponds to a different beam of the TRP, the TRP repeats the beam for four time slots in the row before moving to the next beam. Since each resource repeats in consecutive time slots (e.g., resource 1 repeats in time slots n, n+1, n+2, etc.), the time interval is said to be one time slot. On the other hand, for interleaved sweep 620, the TRP can move from one beam to the next for each subsequent time slot, rotating through four beams for four rounds. Since each resource repeats every four time slots (e.g., resource 1 repeats in time slots n, n+4, n+8, etc.), the time interval is said to be one time slot. Of course, the embodiments are not limited thereto. The resource set may include different amounts of resources and / or repetitions. Furthermore, as noted above, each TRP can have multiple resource sets, multiple TRPs can utilize a single FL, and the UE may be able to measure PRS resources transmitted via multiple FLs.

[0077] Therefore, in order to obtain PRS measurements from PRS signals transmitted in the network by the TRP and / or the UE, the UE can be configured to observe PRS resources for a period of time known as a measurement period. That is, in order to use the PRS signals to determine the UE's location, the UE and the location server (e.g., LMF 220 in Figure 2) can initiate a location communication period in which the UE is given a period of time to observe PRS resources and report the obtained PRS measurements to the location server. As described in more detail below, this measurement period can be determined based on the UE's capabilities.

[0078] In order to measure and process PRS resources during the measurement period, the UE can be configured to perform a measurement interval (MG) mode. For example, the UE can request a measurement interval from the serving TRP, and then the TRP can provide the UE with the configuration (e.g., via the Radio Resource Control (RRC) protocol).

[0079] As noted, the UE can be configured to perform MG mode to measure and process PRS resources concentrated outside the active DL bandwidth portion (BWP), via which the UE sends and receives data using the serving TRP. To allow the network to configure the UE in a manner that adapts to the UE's (which can be dynamic) processing and buffering capabilities, the UE can provide the network (e.g., the TRP or location server) with capabilities related to PRS processing. Various parameters of the MG mode can be configured in light of these capabilities.

[0080] Although many of the communication structures and concepts provided in Figures 3 to 6 are used to provide UE positioning in the systems of Figures 1 and 2 based on uplink (UL) and / or downlink (DL) signals transmitted and / or received by the UE and base station, these communication structures and concepts can also be used to communicate PRS (and other reference signals) between UEs. As noted below with Figures 7A and 7B, 8A and 8B, and 9A and 9B, UEs can use pre-PRS, PRS, and post-PRS communication to coordinate and perform positioning. It can be noted that the message exchange described in Figures 7A and 7B, 8A and 8B, and 9A and 9B is for RTT-based positioning, where the range between the initiating UE and the responding UE is determined based on the time taken for the PRS message to travel between devices.

[0081] Figures 7A and 7B are timing diagrams illustrating examples of pre-PRS message communications that may occur during the pre-PRS phase, according to some configurations. Pre-PRS messages communicated by the initiating UE and the responding UE during the pre-PRS phase can be performed using licensed spectrum. For example, the initiating UE may correspond to UE 105 (to determine its location) in Figures 1 and 2. The responding UE may correspond to UE 145 in Figure 1, which assists in the location determination of the initiating UE 105. In some configurations, the initiating UE may be configured to perform UE location communication with multiple responding UEs to determine the location of the initiating UE relative to the multiple responding UEs.

[0082] Communication examples in timing diagrams 700 and 750 may include pre-PRS messages communicated between initiating UE 705 and two responding UEs 706 and 707. This communication may be initiated by initiating UE 705 and may be based on information included in one or more messages received from responding UEs 706 and 707. For example, in a vehicle application, initiating UE 705 may initiate communication with responding UEs 706 and 707 based on BSMs previously sent by and received by initiating UE 705. Initiating UE 705 may select responding UEs 706 and 707 based on their location attributes. For example, the initiating UE may want to distance responding UEs 706 and 707 because responding UEs 706 and 707 know their locations better than the initiating UE knows its location (e.g., based on confidence associated with location). The initiator UE 705 can use the preceding PRS message 710 to notify the responders UEs 706 and 707.

[0083] In some configurations, the PRS message 710 may include the PRS ID of the PRS that the initiating UE will use to communicate with the responding UEs 706 and 707, when the initiating UE 705 sends its PRS message, and frequency information of the PRS message that the initiating UE 705 uses to send its PRS message to each of the responding UEs 706 and 707.

[0084] In some configurations, the initiating UE 705 may be configured to determine, for each of the responding UEs 706 and 707, when they send their pre-PRS messages 760 and 761 to the initiating UE 705. The initiating UE 705 may be configured to determine, for each of the responding UEs 706 and 707, the PRS ID that each of the responding UEs 706 and 707 will use to communicate its PRS with the initiating UE 705, and when each of the responding UEs 706 and 707 is able to send its PRS message to the initiating UE 705.

[0085] In some configurations, the information for the decision made by the initiating UE 705 regarding each of the responding UEs 706 and 707 may be included in the pre-PRS message 710. In some configurations, the initiating UE 705 may be configured to broadcast the pre-PRS message 710 with the same payload to the responding UEs 706 and 707. Each of the responding UEs 706 and 707 may need to evaluate the pre-PRS message 710 to determine the information that each can use to communicate with the initiating UE 705.

[0086] In some configurations, when the PRS ID of the initiating UE 705 is fixed through multiple PRS exchanges, the initiating UE 705 can send a timing ID associated with the current PRS exchange (or cycle) for each of the multiple PRS exchanges. Information regarding cycles is described below. In some configurations, the timing information when the initiating UE 705 sends its PRS message may include a time determined by the initiating UE 705. Depending on the situation, the timing information when the initiating UE 705 sends its PRS message may include a time determined by an upper layer, such as, for example, the application layer. In some configurations, the timing information regarding when the initiating UE 705 sends its PRS message may include information about the time slot number closest to the time determined by the initiating UE 705 for sending its PRS message. In some configurations, the time slot may be subject to local clock errors. In some configurations, local clock errors can be addressed by reducing the time delay between the PRS message exchanges between the initiating UE 705 and the responding UE. For example, the exchange of PRS messages between initiator UE 705 and responder UE 706 may need to occur within a certain timeframe, so that the clock drift error of initiator UE 705 and responder UE 706 can be minimized. In some cases, local clock error can be addressed by taking into account some clock errors in the timing of the PRS messages sent by the responder UE. For example, initiator UE 705 can be configured to allow some additional time between the time slots of responder UE 706 and UE 707 to ensure signal distinguishability, taking into account clock errors.

[0087] In some configurations, the frequency information used by the initiating UE 705 to transmit the PRS message may include frequencies selected from the available set of total bandwidth. In some configurations, the frequency information may include frequencies selected by sensing interference and selecting one or more channels associated with average reference signal received power (RSRP) interference less than a threshold. In some configurations, the initiating UE 705 may determine the bandwidth used by the responding UEs 706 and 707 to transmit their PRS messages.

[0088] In some configurations, in addition to or instead of broadcasting the pre-PRS message 710 to responder UEs 706 and 707, initiator UE 705 can be configured to unicast a different pre-PRS message to each of responder UEs 706 and 707. The payload of each of these different pre-PRS messages can be different from each other. Initiator UE 705 can use an RRC connection to unicast the different pre-PRS messages.

[0089] Based on the fact that each of the responder UEs 706 and 707 has received the pre-PRS message 710 from the initiator UE 705, each responder UE 706 and 707 may send its pre-PRS message 760 or 761 to the initiator UE 705 at a time determined by the initiator UE 705 and specified in the pre-PRS message 710. In some cases, each of the responder UEs 706 and 707 may broadcast its pre-PRS message 760 or 761.

[0090] Each of the responder UEs 706 and 707 can be configured to acknowledge the PRS ID of the PRS to be sent to the initiating UE 705 using a pre-PRS message 760 or 761. In some configurations, each of the responder UEs 706 and 707 can be configured to determine when each will send its PRS message to the initiating UE 705. In some configurations, timing information regarding when each of the responder UEs 706 and 707 sends its PRS message to the initiating UE 705 can be based on timing information regarding when the initiating UE 705 sends its PRS message (provided by the initiating UE 705 in the pre-PRS message 710) and an α value. This α value can be a number associated with hardware constraints and interference levels. When the PRS processing time is short and the ambient temperature is low, the α value may be low. When the PRS processing time is long and the ambient interference is high, the α value may be high. In some configurations, the timing information for when each initiating UE 706 and 707 sends its PRS message may include information about the slot number closest to the time when the responding UE 706 or 707 decides to send its PRS message. The timing of when the responding UE 706 or 707 decides to send its PRS message may be subject to local clock errors.

[0091] In some configurations, when a fixed PRS ID is used by the initiating UE 705 for each of the responding UEs 706 and 707 via multiple PRS exchanges, the responding UEs 706 and 707 may use the fixed PRS ID determined by the initiating UE 705 as their PRS ID for PRS exchanges. In some configurations, each of the responding UEs 706 and 707 may indicate in the preceding PRS messages 760 and 761 the frequency at which each will be used to transmit its PRS message to the initiating UE 705. In some configurations, the frequency information used by the responding UE 706 or 707 to transmit its PRS message may include frequencies selected from the available set of total bandwidth. In some configurations, the frequency information may include frequencies selected by sensing interference and selecting one or more channels associated with average reference signal received power (RSRP) interference less than a threshold.

[0092] Figures 8A and 8B are timing diagrams illustrating examples of communications that may occur during the PRS phase according to some embodiments. The communication examples in timing diagrams 800 and 850 may include PRS messages communicated between the initiating UE 705 and two responding UEs 706 and 707. In some cases, PRS messages communicated during the PRS phase may be performed using unlicensed spectrum and may be subject to LBT. Using unlicensed spectrum allows the UE to access more bandwidth that can help improve positioning accuracy.

[0093] Based on the fact that the initiator UE 705 has received previous PRS messages 760 and 761 from the responders UE 706 and 707, the initiator UE 705 and the responders UE 706 and 707 know the expected timing of the PRS messages from each other, the PRS ID used by each, and any IDs associated with the current PRS exchange.

[0094] In some configurations, the initiating UE 705 can be configured to broadcast a PRS message 810 to the responding UEs 706 and 707 based on timing information included in its preceding PRS message 710 (shown in FIG. 7A). The PRS message 810 can be used by the initiating UE 705 to send its PRS to the responding UEs 706 and 707. In some configurations, the PRS can be sent by the initiating UE 705 using the comb structure described in FIG. 5. In some configurations, the PRS can be sent by the initiating UE 705 using the transmission techniques described in FIG. 3 to FIG. 6.

[0095] The initiator UE 705 may use the PRS ID and frequency information included in its preceding PRS message 710 to send PRS messages 810 to the responders UE 706 and 707.

[0096] Optionally, the initiator UE 705 may broadcast PRS message 810 based on timing information included in its preceding PRS message 710, which has a random waiting time due to LBT constraints associated with the use of unlicensed spectrum. In some cases, LBT may be performed as a Category 2 (CAT 2) LBT utilizing Fixed Window Idle Channel Assessment (CCA). In some cases, LBT may be performed as a CAT 4 LBT utilizing Variable Window CCA.

[0097] In some configurations, the initiating UE 705 may be configured to store a time instance (e.g., departure time) of when its PRS message 810 was sent to the responding UEs 706 and 707. In some configurations, the time instance may be subject to local clock errors. In some configurations, each of the responding UEs 706 and 707 may be configured to store a time instance (e.g., arrival time) of when it received the PRS message 810 from the initiating UE 705. In some configurations, the time instance may be affected by local clock errors.

[0098] Based on the fact that responder UEs 706 and 707 have received PRS message 810 from initiator UE 705, each of responder UEs 706 and 707 can be configured to broadcast its PRS message 860 or 861 to initiator UE 705 based on timing information included in its preceding PRS messages 760 and 761 (shown in FIG. 7B). PRS messages 860 and 861 can be used by responder UEs 706 and 707 to send their PRS to initiator UE 705.

[0099] In some configurations, each of the responder UEs 706 and 707 may be configured to store a time instance (e.g., departure time) of when its PRS message 860 or 861 was sent to the initiator UE 705. In some configurations, the time instance may be affected by local clock errors.

[0100] Optionally, each of the responders UEs 706 and 707 may broadcast their PRS messages 860 and 861 based on timing information included in their preceding PRS messages 760 and 761, which has a random waiting time due to LBT constraints associated with the use of unlicensed spectrum. In some cases, LBT may be performed as CAT 2 LBT utilizing a fixed window CCA. In some cases, LBT may be performed as CAT 4 LBT utilizing a variable window CCA.

[0101] In some configurations, the initiating UE 705 may be configured to store a time instance (e.g., arrival time) of when it receives PRS messages 860 and 861 from the responding UEs 706 and 707. In some configurations, the time instance may be affected by local clock errors. In some configurations, it may be possible that the initiating UE 705 does not receive PRS message 860, PRS message 861, or both from the responding UEs 706 and 707. When this occurs, the initiating UE 705 may indicate this to the corresponding responding UE 706 and / or 707, as indicated below.

[0102] Figures 9A and 9B are timing diagrams illustrating examples of communications that may occur during the post-PRS phase according to some embodiments. The communication examples in timing diagrams 900 and 950 may include post-PRS messages communicated between the initiating UE 705 and two responding UEs 706 and 707. In some cases, the post-PRS messages communicated during the post-PRS phase may be performed using licensed spectrum. Based on the fact that the initiating UE 705 has received PRS messages 860 and 861 from the responding UEs 706 and 707, the initiating UE 705 may be configured to send a post-PRS message 910 to the responding UEs 706 and 707 using a broadcast or unicast similar to when the initiating UE sends its pre-PRS message 710 (shown in Figure 7A). The post-PRS message 910 may be used by the initiating UE 705 to indicate whether the initiating UE 705 has received PRS messages 860 and 861 from the responding UEs 706 and 707.

[0103] In some configurations, based on the fact that the initiating UE 705 has received PRS messages 860 and 861, the initiating UE 705 can be configured to determine the departure time of PRS message 810 and the arrival time of PRS messages 860 and 861 (shown in Figure 8B). In some configurations, the arrival times of PRS messages 860 and 861 can be determined as a relative time to the departure time of PRS message 810. In some configurations, the relative time can be approximated to the closest multiple of the time scale shared by the initiating UE 701 and the responding UEs 706 and 707. It can be noted that when the initiating UE 705 has not received PRS messages 860, 861, or both, the subsequent PRS message 910 can indicate that one or more of PRS messages 860 and 861 have not been received. In these cases, the departure time of PRS messages 860 or 861 of the responding UE 706 or 707 can be updated (as indicated below). In some cases, the payload for the post-PRS message 910 can be the same for responders UE 706 and 707 (as shown in Figure 9A).

[0104] Based on receiving the subsequent PRS message 910 from the initiating UE 705, each of the responding UEs 706 and 707 can be configured to send its subsequent PRS message 960 or 961 to the initiating UE 705 (as shown in FIG. 9B). The responding UE 706 can use the subsequent PRS message 960 to indicate whether it received the PRS message 810 from the initiating UE 705, the departure time of the responding UE 706's PRS message 860, the arrival time of the initiating UE 705's PRS message 810, and the location of the responding UE 706 at the departure time of the PRS message 860. Similarly, responder UE 707 can use post-PRS message 961 to indicate whether it received PRS message 810 from initiator UE 705, the departure time of responder UE 707's PRS message 861, the arrival time of initiator UE 705's PRS message 810, and the location of responder UE 707 at the departure time of PRS message 861.

[0105] In some configurations, the departure times of the PRS messages 860 and 861 of the responders UEs 706 and 707 can be determined as relative times to the arrival time of the PRS message 810 of the initiating UE 705. In some configurations, the relative time can be approximated to the closest multiple of the time scale shared by the initiating UE 705 and the responders UEs 706 and 707. In some configurations, when the subsequent PRS message 910 indicates that the initiating UE 705 did not receive the PRS message 860 from the responder UE 706 or the PRS message 861 from the responder UE 707, the departure time of the PRS message of the responders UE 706 or 707 in the subsequent PRS message 960 or 961 can be given a "null" value.

[0106] In some configurations, the communication between the initiator UE 705 and the responders UEs 706 and 707 during the pre-PRS phase, PRS phase, and post-PRS phase, as shown in Figures 7A, 7B, 8A, 8B, 9A, and 9B, can be repeated in multiple iterative operations or loops. In some configurations, the loop value can be determined by the initiator UE 705, and the loop counter can be maintained by the initiator UE 705. In some configurations, the loop value can be determined by an upper layer (such as, for example, the application layer). In some configurations, the loop value can be determined based on the speed of the initiator UE and the responder UE, as well as the angular change between the initiator UE and the responder UE. For example, the angular change may be minimal when the initiator UE 705 and the responders UEs 706 and 707 move in the same direction, and therefore, having a large number of loops or iterative operations may be useless. However, as responder UEs 706 and 707 move away from initiator UE 705, multiple geometric and angular changes may occur between the positions of initiator UE 705 and responder UEs 706 and 707. With the separation in distance between initiator UE 705 and responder UEs 706 and 707, the timing data associated with responder UEs 706 and 707 (e.g., the departure time of one reference signal and the arrival time of another reference signal) and the positioning of responder UEs 706 and 707 at time "t1" may differ from the same data at times "t2" and "t3". In this scenario, it may be useful for initiator UE 705 to use a large number of loops to determine its position.

[0107] The loop value can be sent by the initiating UE 705 to the responding UEs 706 and 707 using its preceding PRS message 710 (shown in Figure 7). The loop value can be confirmed by the responding UEs 706 and 707 using their preceding PRS messages 760 and 761. In some cases, the number of loops allows the initiating UE 705 to determine its location at different times based on the different locations of the responding UEs 706 and 707.

[0108] At the end of each cycle, the cycle counter can be incremented by the initiating UE 705 based on the successful receipt of post-PRS messages 960 and 961 from the responding UEs 706 and 707. The initiating UE 705 can then determine its position. In some cases, the determination of the initiating UE 705's position can be performed using any currently available technique, including, for example, the use of a Kalman filter, based at least in part on the departure time of post-PRS message 910, the arrival time of post-PRS messages 960 and 961, and the position of the responding UEs 706 and 707 at the departure time of PRS messages 860 and 861. The cycle of pre-PRS messages, PRS messages, and post-PRS messages can continue into the next cycle. In some cases, the initiating UE 705 can determine when to start the next cycle. In some cases, the start of the next cycle can be determined by the upper layer. When the cycle counter reaches or exceeds the cycle value and after receiving PRS messages 960 and 961 from transponders UE 706 and 707, the positioning communication period between the initiator UE 705 and transponders UE 706 and 707 can be terminated.

[0109] It can be noted that even if the timing diagram examples shown in Figures 7A, 7B, 8A, 8B, 9A and 9B only include two responder UEs, the initiator UE 705 can still initiate multiple location communication periods with more than two responder UEs.

[0110] FIG10 is a flowchart of an example procedure that can be executed by a UE initiating a location communication period according to an embodiment. The initiating UE may correspond to the UE initiating the location communication period. The group of responding UEs may correspond to the UEs responding to the initiating UE. A first message may correspond to a pre-PRS message from the initiating UE. A second message from each of the responding UEs may correspond to a pre-PRS message from each of the responding UEs. A third message may correspond to a post-PRS message from the initiating UE. A fourth message from each of the responding UEs may correspond to a post-PRS message from each of the responding UEs. The components for performing one or more of the illustrated functionalities in the blocks shown in FIG10 may be executed by the hardware and / or software components of the UE. Example components of the UE are illustrated in FIG12, which are described in more detail below.

[0111] These operations can be performed by the initiating UE. At block 1005, functionality includes identifying a group of responding UEs from a plurality of UEs based on the location attributes of each responding UE. Each responding UE can be located near the location of the initiating UE. Each responding UE can be identified based on its location attributes. Location attributes can include the direction the responding UE is moving, its speed, its location confidence, and its location. In some cases, location attributes can be received from the responding UE's BSM. For example, a responding UE can be identified because it is moving in a different direction than the initiating UE. Components used to perform the functionality at block 1005 may include memory 1260, processing unit(s) 1210, wireless communication interface 1230, antenna 1232, and / or other components of the UE, as illustrated in FIG12.

[0112] At block 1010, the functionality includes the initiating UE sending its pre-PRS message (also referred to as the first message) to the group of responding UEs. The pre-PRS message may include one or more characteristics of the transmission of the first reference signal by the initiating UE. The one or more characteristics of the transmission of the first reference signal may include the PRS ID of the first reference signal, timing data indicating when the initiating UE sends the first reference signal to the group of responding UEs, and frequency data indicating the frequency used by the initiated UE to send the first reference signal to the group of responding UEs.

[0113] In some states, the initiating UE may decide on behalf of each responding UE and may include the following information in the first message: when each responding UE may send its first PRS message (also known as the second message) to the initiating UE, the PRS ID of the reference signal (also known as the second reference signal) that each responding UE may use to communicate with the initiating UE, and when each responding UE may send its second reference signal to the initiating UE.

[0114] In some configurations, the first message may also include one or more characteristics of the transmission of the second reference signal for each responding UE. The one or more characteristics of the transmission of the second reference signal for each responding UE may be determined by the initiating UE and may include the PRS ID of the second reference signal that each responding UE can use to communicate with the initiating UE, and information about when the responding UE can send its second reference signal to the initiating UE. It can be noted that the PRS ID used by the responding UE may be different from the PRS ID used by other responding UEs and the PRS ID used by the initiating UE. It can also be noted that the first message from the initiating UE may be broadcast to all responding UEs using the same payload. The transmission described in block 1010 may be performed using licensed spectrum. The transmission may be broadcast. Components used to perform the functionality at block 1010 may include memory 1260, processing unit(s) 1210, wireless communication interface 1230, antenna 1232, and / or other components of the UE, as illustrated in FIG12.

[0115] At block 1020, functionality includes receiving a second message from each responder UE and based on the transmission of a first message, the second confirming that the appropriate responder UE has received the first message from the initiating UE. In some cases, the second message from each responder UE may be broadcast at a time specified by the initiating UE in the first message. The second message from each responder UE may confirm one or more characteristics of the transmission of the responder UE's second reference signal, determined by the initiating UE on behalf of the responder UE. The second message from each responder UE may include data indicating the frequency used by the responder UE to transmit its second reference signal to the initiating UE. It can be noted that each responder UE may transmit its second message to the initiating UE individually (as shown in FIG7B). Components for performing the functionality at block 1020 may include processing unit(s) 1210, wireless communication interface 1230, antenna 1232, and / or other components of the UE, as illustrated in FIG12.

[0116] At block 1030, the functionality includes transmitting a first reference signal to the group of responder UEs and, based on receiving a second message from each of the responder UEs, based on one or more characteristics of the transmission of the first reference signal (as shown in FIG8A). The transmission of the first reference signal to the group of responder UEs may be performed using unlicensed spectrum and may be subject to LBT. Components for performing the functionality at block 1030 may include memory 1260, processing unit(s) 1210, wireless communication interface 1230, antenna 1232, and / or other components of the UE, as illustrated in FIG12.

[0117] In block 1040, functionality includes receiving a second reference signal from each responder UE based on one or more characteristics of the transmission of a second reference signal for each responder UE determined by the initiator UE, and based on the first reference signal. The second reference signal of each responder UE may be received via unlicensed spectrum. Components for performing the functionality at block 1040 may include processing unit(s) 1210, wireless communication interface 1230, antenna 1232, and / or other components of the UE, as illustrated in FIG12.

[0118] At block 1050, functionality includes sending a post-PRS message (also referred to as a third message) to a group of responder UEs and based on receiving a second reference signal from each responder UE. This post-PRS message includes at least an indication of whether the second reference signal from each responder UE was received by the initiating UE. In some configurations, the third message may also include timing data related to the departure time of the first reference signal and timing data related to the arrival time of the second reference signal from each responder UE. The third message may be sent using licensed spectrum. The third message may be broadcast to all responder UEs having the same payload. Components for performing the functionality at block 1050 may include memory 1260, processing unit(s) 1210, wireless communication interface 1230, antenna 1232, and / or other components of the UE, as illustrated in FIG12.

[0119] At block 1060, functionality includes receiving a post-PRS message (also referred to as a fourth message) from each responder UE and based on the transmission of a third message. This post-PRS message includes timing data related to the departure time of a second reference signal for each responder UE, timing data related to the arrival time of a first reference signal, and the location of the responder UE at the departure time of the second reference signal. The fourth message can be received via licensed spectrum. Components for performing the functionality at block 1040 may include processing unit(s) 1210, wireless communication interface 1230, antenna 1232, and / or other components of the UE, as illustrated in FIG12.

[0120] Figure 11 is a flowchart of an example procedure that can be executed by a responder UE during a location communication period according to an embodiment. The location communication period can be initiated by an initiating UE based on the location attributes of the responder UE. The responder UE can be one of a plurality of responder UEs identified by the initiating UE based on the location attributes of the responder UE. The components for performing one or more of the illustrated functionalities in the blocks shown in Figure 11 can be executed by the hardware and / or software components of the UE. Example components of the UE are illustrated in Figure 12, which are described in more detail below.

[0121] At block 1110, the functionality includes receiving a first message from the initiating UE, the first message including one or more characteristics of the transmission of a first reference signal of the initiating UE. The one or more characteristics of the transmission of the first reference signal may include the ID of the first reference signal, timing data related to the time slot used by the initiated UE to send the first reference signal to the responding UE, and frequency data related to the frequency used by the initiated UE to send the first reference signal to the responding UE.

[0122] The first message may also include one or more characteristics of the transmission of the second reference signal of the responding UE. The one or more characteristics of the transmission of the second reference signal of the responding UE may be determined by the initiating UE on behalf of the responding UE. The one or more characteristics of the transmission of the second reference signal of one responding UE may be different from the one or more characteristics of the transmission of the second reference signal of another responding UE. The first message may also include information about when the responding UE may send its previous PRS message (also referred to as the second message) to the initiating UE. The components for performing the functionality at block 1110 may include (multiple) processing units 1210, wireless communication interface 1230, antenna 1232 and / or other components of the UE, as illustrated in FIG12.

[0123] At block 1120, the functionality includes sending a second message to the initiating UE, the second message confirming that the responding UE has received the first message from the initiating UE. The second message from the responding UE may include frequency data related to the frequency used by the responded UE to send the second reference signal of the responding UE to the initiating UE. The components for performing the functionality at block 1120 may include (multiple) processing units 1210, wireless communication interfaces 1230, antennas 1232, and / or other components of the UE, as illustrated in FIG12.

[0124] At block 1130, the functionality includes receiving the first reference signal from the initiating UE and based on one or more characteristics of the transmission of the first reference signal based on the transmission of a second message. The first reference signal may be received using unlicensed spectrum. The components for performing the functionality at block 1130 may include processing unit(s) 1210, wireless communication interface 1230, antenna 1232, and / or other components of the UE, as illustrated in FIG12.

[0125] In block 1140, functionality includes transmitting a second reference signal of the responding UE to the initiating UE and, based on the reception of the first reference signal, to transmit a second reference signal of the responding UE based on one or more characteristics. The second reference signal may be transmitted using unlicensed spectrum and may be subject to LBT. Components for performing the functionality at block 1140 may include processing unit(s) 1210, wireless communication interface 1230, antenna 1232, and / or other components of the UE, as illustrated in FIG12.

[0126] At block 1150, functionality includes receiving a third message from the initiating UE and based on the transmission of a second reference signal, the third message including at least an indication that the second reference signal is received by the initiating UE. The third message may be received using licensed spectrum. Components for performing the functionality at block 1150 may include processing unit(s) 1210, wireless communication interface 1230, antenna 1232, and / or other components of the UE, as illustrated in FIG12.

[0127] At block 1160, the functionality includes sending a fourth message to the initiating UE and based on receiving a third message. This fourth message includes timing data related to the departure time of the responding UE's second reference signal, timing data related to the arrival time of the first reference signal, and the location of the responding UE at the departure time of the responding UE's second reference signal. The fourth message can be transmitted using licensed spectrum. Components for performing the functionality at block 1160 may include processing unit(s) 1210, wireless communication interface(s) 1230, antenna(s) 1232, and / or other components of the UE, as illustrated in FIG12.

[0128] FIG. 12 illustrates an embodiment of UE 105, which can be utilized as described above (e.g., in conjunction with FIGS. 7 to 11). For example, UE 105 can perform one or more functions of the methods shown in FIGS. 10 and 11. It should be noted that FIG. 12 is intended only to provide a generalized illustration of various elements, and any or all of them can be used appropriately. Additionally, it can be noted that in some cases, the elements illustrated in FIG. 12 can be localized to a single physical device and / or distributed among various networked devices, and these elements can be located in different physical locations. Furthermore, as previously noted, the functionality of the UE discussed in the previously described embodiments can be performed by one or more of the hardware and / or software elements illustrated in FIG. 12.

[0129] UE 105 is shown as including hardware elements that can be electrically coupled (or otherwise communicated) via bus 1205. The hardware elements may include (a plurality of) processing units 1210, which may include, but are not limited to, one or more general-purpose processors, one or more special-purpose processors (such as digital signal processor (DSP) chips, graphics accelerator processors, application-specific integrated circuits (ASICs), etc.) and / or other processing structures or components. As shown in FIG12, some embodiments may have a separate DSP 1220, depending on the desired functionality. Location determination and / or other determinations based on wireless communication may be provided in (a plurality of) processing units 1210 and / or wireless communication interface 1230 (discussed below). UE 105 may also include one or more input devices 1270 and one or more output devices 1215. The one or more input devices 1270 may include, but are not limited to, a keyboard, a touch screen, a touchpad, a microphone, buttons, a dial, a switch, etc., and the one or more output devices 1215 may include, but are not limited to, one or more displays (e.g., touch screens), light-emitting diodes (LEDs), speakers, etc.

[0130] UE 105 may also include a wireless communication interface 1230, which may include, but is not limited to, a modem, network card, infrared communication device, wireless communication device and / or chipset (such as Bluetooth® device, IEEE 802.11 device, IEEE 802.15.4 device, Wi-Fi device, WiMax device, WAN device and / or various cellular devices, etc.), which enables UE 105 to communicate with other devices as described in the above embodiments. As described herein, the wireless communication interface 1230 may permit communication (e.g., sending and receiving) of data and signals with the TRP of the network, for example, via eNB, gNB, ng-eNB, access point, various base stations and / or other access node types, and / or other network components, computer systems and / or any other electronic devices coupled to the TRP. This communication may be implemented via one or more wireless communication antennas 1232 that transmit and / or receive wireless signals 1234. According to some embodiments, the (multiple) wireless communication antennas 1232 may include a plurality of individual antennas, antenna arrays, or any combination thereof. The (multiple) antennas 1232 may be capable of transmitting and receiving wireless signals using beamforming (e.g., Tx beamforming and Rx beamforming). Beamforming may be performed using digital and / or analog beamforming techniques, utilizing corresponding digital and / or analog circuitry. The wireless communication interface 1230 may include such circuitry.

[0131] Depending on the desired functionality, the wireless communication interface 1230 may include separate receivers and transmitters, or any combination of transceivers, transmitters, and / or receivers, to communicate with base stations (e.g., ng-eNBs and gNBs) and other terrestrial transceivers (such as wireless devices and access points). The UE 105 may communicate with various data networks, including a variety of network types. For example, a wireless wide area network (WWAN) may be a CDMA network, a time division multiple access (TDMA) network, a frequency division multiple access (FDMA) network, an orthogonal frequency division multiple access (OFDMA) network, a single-carrier frequency division multiple access (SC-FDMA) network, a WiMAX (IEEE 802.16) network, and so on. A CDMA network may implement one or more RATs, such as CDMA2000®, WCDMA, etc. CDMA2000® includes the IS-95, IS-2000, and / or IS-856 standards. TDMA networks can implement GSM, Advanced Digital Mobile Telephone Systems (D-AMPS), or some other RAT. OFDMA networks can use LTE, Advanced LTE, 5G NR, etc. 5G NR, LTE, Advanced LTE, GSM, and WCDMA are described in documents from 3GPP. CDMA2000® is described in documents from the "3rd Generation Partnership Project X3" (3GPP2) alliance. 3GPP and 3GPP2 documents are publicly available. Wireless Local Area Networks (WLANs) can also be IEEE 802.11x networks, and Wireless Personal Area Networks (WPANs) can be Bluetooth, IEEE 802.15x, or some other type of network. The technologies described herein can also be used in any combination of WWAN, WLAN, and / or WPAN.

[0132] UE 105 may also include (multiple) sensors 1240. (Multiple) sensors 1240 may include, but are not limited to, one or more inertial sensors and / or other sensors (e.g., (multiple) accelerometers, (multiple) gyroscopes, (multiple) cameras, (multiple) magnetometers, (multiple) altimeters, (multiple) microphones, (multiple) proximity sensors, (multiple) light sensors, (multiple) barometers, etc.), some of which may be used to obtain positioning-related measurements and / or other information.

[0133] Embodiments of UE 105 may also include a Global Navigation Satellite System (GNSS) receiver 1280 capable of receiving signals 1284 from one or more GNSS satellites using a GNSS antenna 1282 (which may be the same as antenna 1232). Positioning based on GNSS signal measurements may be used to supplement and / or combine with the techniques described herein. GNSS receiver 1280 may use known techniques to extract the positioning of UE 105 from GNSS satellites 110 of GNSS systems such as Global Positioning System (GPS), Galileo, GLONASS, Japan's Quasi-Zenith Satellite System (QZSS), India's Indian Regional Navigation Satellite System (IRNSS), China's BeiDou Navigation Satellite System (BDS), etc. In addition, the GNSS receiver 1280 can be used with various augmentation systems, such as satellite-based augmentation systems (SBAS), which can be associated with or otherwise enabled to be used with one or more global and / or regional navigation satellite systems, such as, for example, the Wide Area Augmentation System (WAAS), the European Geostationary Navigation Coverage Service (EGNOS), the Multifunctional Satellite Augmentation System (MSAS), and the Geostationary Augmentation Navigation System (GAGAN).

[0134] It can be noted that although the GNSS receiver 1280 is illustrated as a different component in FIG. 12, the embodiments are not limited thereto. As used herein, the term "GNSS receiver" may include hardware and / or software components configured to acquire GNSS measurements (measurements from GNSS satellites). Thus, in some embodiments, the GNSS receiver may include a measurement engine (as software) executed by one or more processing units (such as processing units 1210(s), DSP 1220, and / or processing units within the wireless communication interface 1230 (e.g., in a modem)). The GNSS receiver may also optionally include a positioning engine that can use GNSS measurements from the measurement engine to determine the positioning of the GNSS receiver using an extended Kalman filter (EKF), weighted least squares (WLS), a hash filter, a particle filter, etc. The positioning engine may also be executed by one or more processing units, such as processing unit 1210(s) or DSP 1220.

[0135] UE 105 may also include and / or communicate with memory 1260. Memory 1260 may include, but is not limited to, local and / or network-accessible storage, disk drives, drive arrays, optical storage devices, solid-state storage devices, such as random access memory (RAM) and / or read-only memory (ROM), which may be programmable, flash memory updatable, etc. Such storage devices may be configured to implement any suitable data storage, including but not limited to various file systems, database structures, etc.

[0136] As described herein, the memory 1260 of the UE 105 may also include software elements (not shown in FIG. 12), including operating systems, device drivers, executable libraries, and / or other code, such as one or more applications, which may include computer programs provided by various embodiments and / or may be designed to implement methods and / or configuration systems provided by other embodiments. By way of example only, one or more programs described with respect to the above-described methods may be implemented as code and / or instructions in the memory 1260 executable by the UE 105 (and / or the processing units 1210 or DSP 1220 within the UE 105). Then, in one embodiment, such code and / or instructions may configure and / or adapt a general-purpose computer (or other device) to perform one or more operations according to the described methods.

[0137] It will be apparent to those skilled in this technology that substantial changes can be made to suit specific requirements. For example, custom hardware and / or specific elements that can be implemented in hardware, software (including portable software, such as applets), or both can be used. Furthermore, connections to other computing devices, such as network input / output devices, can be employed.

[0138] Referring to the accompanying drawings, elements that may include memory may include non-transitory machine-readable media. As used herein, the terms "machine-readable media" and "computer-readable media" refer to any storage medium involved in providing data that enables a machine to operate in a particular manner. In the embodiments provided above, various machine-readable media may be involved in providing instructions / code to a processing unit and / or (a plurality of) other devices for execution. Additionally or alternatively, machine-readable media may be used to store and / or carry such instructions / code. In many implementations, computer-readable media are physical and / or tangible storage media. Such media can take many forms, including but not limited to non-volatile and volatile media. Common forms of computer-readable media include, for example, magnetic and / or optical media, any other physical media having a hole pattern, RAM, programmable ROM (PROM), erasable PROM (EPROM), flash EPROM, any other memory chip or memory cartridge, or any other media from which a computer can read instructions and / or code.

[0139] The methods, systems, and devices discussed herein are examples. Various embodiments may appropriately omit, substitute, or add various programs or elements. For example, features described with respect to certain embodiments may be combined in various other embodiments. Different forms and elements of embodiments may be combined in a similar manner. Various elements of the figures provided herein may be embodied in hardware and / or software. Likewise, technology is evolving, and therefore many elements are examples that do not limit the scope of this application to those specific examples.

[0140] It has been proven that, primarily for reasons of general use, it is sometimes convenient to refer to such signals as bits, information, values, elements, symbols, characters, variables, terms, numbers, numerical values, etc. However, it should be understood that all such terms or similar terms will be associated with appropriate physical quantities and are merely convenient labels. Unless specifically stated, it is evident from the above discussion that throughout this specification, discussions using terms such as "processing," "calculating," "measuring," "determining," "identifying," "associating," "measuring," "executing," etc., refer to the actions or procedures of a specific device (such as a dedicated computer or similar dedicated electronic computing device). Therefore, in the context of this specification, a dedicated computer or similar dedicated electronic computing device is capable of manipulating or converting signals, which are typically represented as physical electronic, electrical, or magnetic quantities within the memory, registers, or other information storage devices, transmission devices, or display devices of the dedicated computer or similar dedicated electronic computing device.

[0141] The terms “and” and “or” as used herein can include a wide variety of meanings, which are also expected to depend at least in part on the context in which such terms are used. Typically, “or”, if used in an associative list such as A, B, or C, is intended to mean A, B, and C, and is used herein in an inclusive sense, while A, B, or C is used herein in an exclusive sense. Additionally, the term “one or more” as used herein can be used to describe any feature, structure, or characteristic in the singular, or can be used to describe some combination of features, structures, or characteristics. However, it should be noted that this is merely an illustrative example, and the claimed subject matter is not limited to this example. Furthermore, the term “at least one”, if used in an associative list such as A, B, or C, can be interpreted as meaning any combination of A, B, and / or C, such as A, AB, AA, AAB, AABBCCC, etc.

[0142] Several embodiments have been described, and various modifications, alternative constructions, and equivalents may be used without departing from the scope of this invention. For example, the above-described elements may simply be elements of a larger system, wherein other rules may take precedence over or otherwise modify the application of the various embodiments. Similarly, several steps may be performed before, during, or after considering the above-described elements. Accordingly, the above description does not limit the scope of this invention.

[0143] In view of this description, embodiments may include different combinations of features. Examples of implementations are described in the following numbered clauses: Clause 1. A method for locating an initiating user equipment (UE), the method comprising: identifying a group of responding UEs from a plurality of UEs by an initiating UE based on location attributes of each responding UE in a group of responding UEs, the group of responding UEs having two or more responding UEs; sending a first message from the initiating UE to the group of responding UEs, the first message including: one or more characteristics of the transmission of an initiation reference signal by the initiating UE; one or more characteristics of the transmission of a response reference signal by each responding UE in the group of responding UEs; and information regarding when each responding UE is able to send its second message to the initiating UE; receiving the second message from a first UE of each responding UE and based on the transmission of the first message, the second message confirming receipt of the first message by each responding UE; sending an initiation reference signal from the initiating UE to the group of responding UEs and based on the receipt of the second message by each responding UE, based on one or more characteristics of the transmission of the initiation reference signal; The method comprises: receiving a response reference signal from a first UE based on the transmission of an initiating reference signal and based on one or more characteristics of the response reference signal transmission of each responder UE; sending a third message from the first UE to the group of responder UEs based on the received response reference signal, the third message including at least an indication that the first UE has received the response reference signal of each responder UE; and receiving a fourth message from each responder UE based on the transmission of the third message, the fourth message including timing data related to the departure time of the response reference signal of each responder UE, timing data related to the arrival time of the initiating reference signal received by each responder UE, and the position of the responder UE at the departure time of the response reference signal of each responder UE. Clause 2. The method according to Clause 1 further comprises: determining the position of the initiator UE relative to each responder UE based on: timing data related to the departure time of the response reference signal of each responder UE, timing data related to the arrival time of the initiating reference signal at each responder UE, or the position of each responder UE at the departure time of the response reference signal of each responder UE, or a combination thereof. Clause 3. According to the method of Clause 1, one or more characteristics of the transmission of the initiating reference signal include an identifier (ID) of the initiating reference signal, timing data indicating when the initiating UE sends the initiating reference signal to the group of responding UEs, or frequency data indicating the frequency used by the initiating UE to send the initiating reference signal to the group of responding UEs, or a combination thereof.Clause 4. According to the method of Clause 1, one or more characteristics of the transmission of the response reference signal of each responder UE include an identifier (ID) of the response reference signal of each responder UE and timing data indicating when each responder UE transmits its response reference signal. Clause 5. According to the method of Clause 1, the transmission of the first and third messages and the reception of the second and fourth messages are performed using licensed spectrum. Clause 6. According to the method of Clause 1, the transmission of the initiation reference signal by the initiator UE and the reception of the response reference signal of each responder UE are performed using unlicensed spectrum. Clause 7. According to the method of Clause 1, the location attributes of each responder UE include the direction of movement of the responder UE, the location confidence of the responder UE, the speed of the responder UE, or the location of the responder UE, or a combination thereof. Clause 8. According to the method of Clause 7, the initiator UE identifies each responder UE from a plurality of UEs based on the responder UE having a higher location confidence than the initiator UE. Clause 9. According to the method of Clause 7, each responding UE is identified from among a plurality of UEs based on the fact that the responding UE is moving in a direction different from the direction in which the initiating UE is moving. Clause 10. According to the method of Clause 7, the transmission of the first message, the initiation reference signal, and the third message of the initiating UE, and the reception of the second message, the response reference signal, and the fourth message of each responding UE are repeated a certain number of cycles.Clause 11. An initiator user equipment (UE) for wireless communication, the initiator UE comprising: one or more transceivers; memory; and one or more processors communicatively coupled to the memory and the one or more transceivers, the one or more processors being configured to: identify a group of responder UEs from a plurality of UEs based on location attributes of each responder UE in a group of responder UEs, the group of responder UEs having two or more responder UEs; transmit a first message to the group of responder UEs, the first message including: one or more characteristics of the transmission of an initiation reference signal of the initiator UE; one or more characteristics of the transmission of a response reference signal of each responder UE in the group of responder UEs; and information regarding when each responder UE can transmit its second message to the initiator UE; receive the second message from each responder UE and based on the transmission of the first message, the second message confirming reception of the first message by each responder UE; transmit an initiation reference signal to the group of responder UEs and based on the reception of the second message of each responder UE, based on one or more characteristics of the transmission of the initiation reference signal; Receive a response reference signal from each responder UE based on one or more characteristics of the transmission of the response reference signal from each responder UE, based on the issuance of the initiating reference signal; send a third message to the group of responder UEs based on the receipt of the response reference signal from each responder UE, the third message including at least an indication that the initiating UE has received the response reference signal from each responder UE; and receive a fourth message from each responder UE based on the issuance of the third message, the fourth message including timing data related to the departure time of the response reference signal from each responder UE, timing data related to the arrival time of the initiating reference signal received by each responder UE, and the location of each responder UE at the departure time of the response reference signal from each responder UE. Clause 12. According to Clause 11, the initiating UE, wherein one or more processors are further configured to determine the position of the initiating UE relative to each responding UE based on: timing data related to the departure time of the second reference signal of each responding UE, timing data related to the arrival time of the initiating reference signal at each responding UE, or the position of each responding UE at the departure time of the responding UE's response reference signal, or a combination thereof. Clause 13. According to Clause 11, the initiating UE, wherein one or more characteristics of the transmission of the initiating reference signal include an identifier (ID) of the initiating reference signal, timing data indicating when the initiating UE sends the initiating reference signal to the group of responding UEs, and frequency data indicating the frequency at which the initiated UE sends the initiating reference signal to the group of responding UEs.Clause 14. The initiating UE according to Clause 11, wherein one or more characteristics of the transmission of the response reference signal of each responding UE include an identifier (ID) of the response reference signal of each responding UE and timing data indicating when each responding UE transmits its response reference signal. Clause 15. The initiating UE according to Clause 11, wherein the transmission of the first and third messages and the reception of the second and fourth messages are performed using licensed spectrum. Clause 16. The initiating UE according to Clause 11, wherein the transmission of the initiating reference signal by the initiating UE and the reception of the response reference signal by each responding UE are performed using unlicensed spectrum. Clause 17. The initiating UE according to Clause 11, wherein the location attributes of each responding UE include the direction of movement of the responding UE, the location confidence of the responding UE, or the speed of the responding UE and the location of the responding UE, or a combination thereof. Clause 18. The initiating UE according to Clause 17, wherein the initiating UE identifies each responding UE from a plurality of UEs based on the responding UE having a higher location confidence than the initiating UE's location confidence. Clause 19. The initiating UE according to Clause 17, wherein the initiating UE identifies each responding UE from a plurality of UEs based on the responding UE being moved in a direction different from the direction the initiating UE is moving. Clause 20. The initiating UE according to Clause 11, wherein the transmission of the initiating UE's first message, initiation reference signal, and third message, and the reception of each responding UE's second message, response reference signal, and fourth message, are repeated a certain number of times. Clause 21. A method for locating an initiating user equipment (UE), the method being performed by a responding UE and comprising: receiving a first message from the initiating UE, the first message including one or more characteristics of the transmission of a first reference signal of the initiating UE and one or more characteristics of the transmission of a second reference signal of the responding UE, wherein the responding UE is identified by the initiating UE from a plurality of UEs based on the responding UE's location attributes; sending a second message to the initiating UE, the second message confirming receipt of the first message by the initiating UE; receiving the first reference signal from the initiating UE and based on the sending of the second message, according to one or more characteristics of the transmission of the first reference signal; and sending a second reference signal to the initiating UE and based on the receipt of the first reference signal, according to one or more characteristics of the transmission of the second reference signal. The initiating UE receives a third message based on the transmission of the second reference signal, the third message including at least an indication that the initiating UE has received the second reference signal; and sends a fourth message to the initiating UE based on the reception of the third message from the initiating UE, the fourth message including timing data related to the departure time of the second reference signal, timing data related to the arrival time of the first reference signal, and the location of the responding UE at the departure time of the second reference signal.Clause 22. According to the method of Clause 21, one or more characteristics of the transmission of the first reference signal include an identifier (ID) of the first reference signal, timing data associated with the time slot used by the initiating UE to transmit the first reference signal to the responding UE, and frequency data associated with the frequency used by the initiating UE to transmit the first reference signal to the responding UE. Clause 23. According to the method of Clause 21, one or more characteristics of the transmission of the second reference signal include an identifier (ID) of the second reference signal and timing data associated with the time slot used by the responding UE to transmit the second reference signal to the initiating UE. Clause 24. According to the method of Clause 23, the second message further includes frequency data associated with the frequency used by the responding UE to transmit the second reference signal to the initiating UE. Clause 25. According to the method of Clause 21, the reception of the first and third messages by the responding UE and the transmission of the second and fourth messages by the responding UE are performed using licensed spectrum. Clause 26. According to the method of Clause 21, the reception of the first reference signal and the transmission of the second reference signal by the responding UE are performed using unlicensed spectrum. Clause 27. According to the method of Clause 21, the location attributes of the responder UE include the direction in which the responder UE is moving, the location confidence of the responder UE, the speed of the responder UE, or the location of the responder UE, or a combination thereof. Clause 28. According to the method of Clause 27, the location confidence of the responder UE is higher than the location confidence of the initiator UE. Clause 29. According to the method of Clause 27, the initiator UE identifies the responder UE from a plurality of UEs based on the responder UE moving in a direction different from the direction in which the initiator UE is moving.Clause 30. A responder user equipment (UE) for wireless communication, the responder UE comprising: a transceiver; memory; and one or more processors communicatively coupled to the memory and the transceiver, the one or more processors being configured to: receive a first message from an initiating UE, the first message including one or more characteristics of the transmission of a first reference signal of the initiating UE and one or more characteristics of the transmission of a second reference signal of the responder UE, wherein the responder UE is identified by the initiating UE from a plurality of UEs based on the responder UE's location attributes; send a second message to the initiating UE, the second message at least indicating acknowledgment by the responder UE of receiving the first message from the initiating UE; receive the first reference signal from the initiating UE and based on sending the second message, based on one or more characteristics of the transmission of the first reference signal; send the second reference signal to the initiating UE and based on receiving the first reference signal, based on one or more characteristics of the transmission of the second reference signal. The respondent UE receives a third message from the initiating UE based on the transmission of a second reference signal, the third message including at least an indication that the initiating UE has received the second reference signal; and sends a fourth message to the initiating UE based on the reception of the third message from the initiating UE, the fourth message including timing data related to the departure time of the second reference signal, timing data related to the arrival time of the first reference signal, and the location of the responding UE at the departure time of the second reference signal. Clause 31. The responding UE according to Clause 30, wherein one or more characteristics of the transmission of the first reference signal include an identifier (ID) of the first reference signal, timing data related to the time slot used by the initiated UE to transmit the first reference signal to the responding UE, and frequency data related to the frequency used by the initiated UE to transmit the first reference signal to the responding UE. Clause 32. The responding UE according to Clause 30, wherein one or more characteristics of the transmission of the second reference signal include an identifier (ID) of the second reference signal and timing data related to the time slot used by the responded UE to transmit the second reference signal to the initiating UE. Clause 33. According to Clause 32, the respondent UE further includes frequency data related to the frequency used by the responded UE to transmit the second reference signal to the initiating UE. Clause 34. According to Clause 30, the respondent UE receives the first and third messages using licensed spectrum, and the respondent UE transmits the second and fourth messages using licensed spectrum. Clause 35. According to Clause 30, the respondent UE receives the first reference signal using unlicensed spectrum, and the respondent UE transmits the second reference signal using unlicensed spectrum. Clause 36. According to Clause 30, the respondent UE's location attributes include the direction the respondent UE is moving, the respondent UE's location confidence, the respondent UE's speed, or the respondent UE's location, or a combination thereof.Clause 37. A respondent UE according to Clause 36, wherein the location confidence of the respondent UE is higher than that of the initiating UE. Clause 38. A respondent UE according to Clause 36, wherein the initiating UE identifies the respondent UE from a plurality of UEs based on the respondent UE being moved in a direction different from the direction the initiating UE is moving. [Simplified Explanation of the Diagram]

[0009] Figure 1 is a diagram of a positioning system according to an embodiment.

[0010] Figure 2 is a diagram of a fifth-generation (5G) new radio (NR) positioning system according to an embodiment, illustrating an embodiment of a positioning system (e.g., the positioning system of Figure 1) implemented within a 5G NR communication system.

[0011] Figure 3 is a diagram illustrating an example of a frame structure for NR and associated terms according to an embodiment.

[0012] Figure 4 is a diagram illustrating an example of a wireless communication frame sequence with positioning timing of a positioning reference signal (PRS) according to an embodiment.

[0013] Figure 5 is a diagram showing examples of different comb sizes used with different numbers of symbols according to an embodiment.

[0014] Figure 6 is a timing diagram illustrating two different options for the use of time slots for resource sets according to an embodiment.

[0015] Figures 7A and 7B are timing diagrams illustrating examples of pre-PRS message communications that can occur during the pre-PRS phase according to some patterns.

[0016] Figures 8A and 8B are timing diagrams illustrating examples of PRS message communications that can occur during the PRS phase according to some patterns.

[0017] Figures 9A and 9B are timing diagrams illustrating examples of communication of post-PRS messages that can occur during the post-PRS phase according to an embodiment.

[0018] Figure 10 is a flowchart of an example program that can be executed by the initiator UE initiating the location communication period according to an embodiment.

[0019] Figure 11 is a flowchart of an example procedure that can be executed by a responder UE that responds to an initiator UE according to an embodiment.

[0020] Figure 12 is a block diagram of an embodiment of a UE that can be utilized in the embodiments described herein.

[0021] Depending on some example implementations, the same reference symbols in the various figures indicate the same elements. [Biomaterial Storage]

[0145] Domestic storage information (please note in order of storage institution, date, and number): None. International storage information (please note in order of storage country, institution, date, and number): None.

Claims

1. A method for locating an initiator user equipment (UE), the method comprising: The initiating UE identifies a group of responding UEs from a plurality of UEs based on the location attributes of each responding UE in the group of responding UEs, the group of responding UEs having two or more responding UEs; The initiating UE sends a first message to the responding UE, the first message including: one or more characteristics of a transmission of an initiating reference signal of the initiating UE; The group of responding UEs includes one or more characteristics of a transmission of a response reference signal for each responding UE; and information regarding when each responding UE can send its second message to the initiating UE; the initiating UE receives a second message from each responding UE and based on the transmission of the first message, the second message confirming the reception of the first message by each responding UE; the initiating UE sends the initiation reference signal to the group of responding UEs and based on the reception of the second message by each responding UE, based on the one or more characteristics of the transmission of the initiation reference signal; the initiating UE receives the response reference signal from each responding UE and based on the one or more characteristics of the transmission of the response reference signal by each responding UE, based on the transmission of the initiation reference signal. The initiating UE sends a third message to the group of responding UEs and based on receiving the response reference signal from each responding UE, the third message including at least an indication from the initiating UE that it has received the response reference signal from each responding UE; and receives a fourth message from each responding UE and based on the sending of the third message, the fourth message including timing data related to a departure time of the response reference signal from each responding UE and an arrival time of the initiating reference signal received by each responding UE, and a location of each responding UE at the departure time of the response reference signal from each responding UE.

2. According to the method of request item 1, it also includes: The position of the initiating UE relative to each responding UE is determined based on the following: timing data related to the departure time of the response reference signal of each responding UE, timing data related to the arrival time of the initiating reference signal at each responding UE, or the position of each responding UE at the departure time of the response reference signal of each responding UE, or a combination thereof.

3. The method according to claim 1, wherein the one or more characteristics of the transmission of the initiation reference signal include an identifier (ID) of the initiation reference signal, timing data indicating when the initiator UE sends the initiation reference signal to the group of responder UEs, or frequency data indicating a frequency used by the initiator UE to send the initiation reference signal to the group of responder UEs, or a combination thereof.

4. The method according to claim 1, wherein the one or more characteristics of the transmission of the response reference signal of each responder UE include an identifier (ID) of the response reference signal of each responder UE and timing data indicating when each responder UE sends its response reference signal.

5. The method according to request item 1, wherein the transmission of the first and third messages and the reception of the second and fourth messages are performed using licensed spectrum.

6. The method according to request item 1, wherein the transmission of the initiation reference signal by the initiating UE and the reception of the response reference signal by each responding UE are performed using unlicensed spectrum.

7. According to the method of request item 1, wherein the location attribute of each responder UE includes a direction in which the responder UE is moving, a location confidence of the responder UE, a speed of the responder UE, or a location of the responder UE, or a combination thereof.

8. The method according to request item 7, wherein the initiator UE identifies each responder UE from the plurality of UEs based on the responder UE having a higher location confidence than the initiator UE.

9. The method according to request item 7, wherein the initiator UE identifies each responder UE from the plurality of UEs based on the fact that the responder UE is moving in a direction different from the direction in which the initiator UE is moving.

10. The method according to request item 7, wherein the transmission of the first message, the initiation reference signal and the third message of the initiating UE and the reception of the second message, the response reference signal and the fourth message of each responding UE are repeated a certain number of times.

11. An initiator user equipment (UE) for wireless communication, the initiator UE comprising: One or more transceivers; memory; and one or more processors communicatively coupled to the memory and the one or more transceivers, the one or more processors being configured to: identify a group of responder UEs from a plurality of UEs based on the location attributes of each responder UE in the group of responder UEs, the group of responder UEs having two or more responder UEs. Send a first message to the group of responders UEs, the first message including: one or more features of a transmission of an initiation reference signal of the initiator UE; The group of responder UEs includes one or more characteristics of a transmission of a response reference signal for each responder UE; and information regarding when each responder UE can send its second message to the initiating UE; receiving a second message from each responder UE and based on the sending of the first message, the second message confirming receipt of the first message by each responder UE; sending the initiating reference signal to the group of responder UEs and based on the receipt of the second message by each responder UE, based on the one or more characteristics of the transmission of the initiating reference signal; receiving the response reference signal from each responder UE and based on the sending of the initiating reference signal, based on the one or more characteristics of the transmission of the response reference signal by each responder UE; The system sends a third message to the group of responder UEs and, based on receiving the response reference signal from each responder UE, the third message including at least an indication from the initiating UE that it has received the response reference signal from each responder UE; and receives a fourth message from each responder UE and, based on the sending of the third message, the fourth message including timing data related to a departure time of the response reference signal from each responder UE and an arrival time of the initiating reference signal received by each responder UE, and a location of each responder UE at the departure time of the response reference signal from each responder UE.

12. The initiator UE according to request item 11, wherein the one or more processors are further configured to determine a position of the initiator UE relative to the position of each responder UE based on: timing data related to the departure time of the response reference signal of each responder UE, timing data related to the arrival time of the initiation reference signal at each responder UE, or the position of each responder UE at the departure time of the response reference signal of each responder UE, or a combination thereof.

13. The initiator UE according to request item 11, wherein the one or more characteristics of the transmission of the initiation reference signal include an identifier (ID) of the initiation reference signal, timing data indicating when the initiator UE sends the initiation reference signal to the group of responder UEs, and frequency data indicating a frequency used by the initiator UE to send the initiation reference signal to the group of responder UEs.

14. The initiating UE according to request item 11, wherein the one or more characteristics of the transmission of the response reference signal of each responding UE include an identifier (ID) of the response reference signal of each responding UE and timing data indicating when each responding UE sends its response reference signal.

15. The UE that initiated the request 11, wherein the transmission of the first and third messages and the reception of the second and fourth messages are performed using licensed spectrum.

16. The initiator UE according to request item 11, wherein the transmission of the initiation reference signal by the initiator UE and the reception of the response reference signal by each responder UE are performed using unlicensed spectrum.

17. According to the initiator UE of request item 11, wherein the location attribute of each responder UE includes a direction in which the responder UE is moving, a location confidence of the responder UE, a speed of the responder UE, or a location of the responder UE, or a combination thereof.

18. The initiator UE according to request item 17, wherein the initiator UE identifies each responder UE from the plurality of UEs based on the responder UE having a higher location confidence than the initiator UE.

19. The initiator UE according to request item 17, wherein the initiator UE identifies each responder UE from the plurality of UEs based on the responder UE being moved in a direction different from the direction in which the initiator UE is moving.

20. The initiator UE according to request item 11, wherein the transmission of the first message, the initiation reference signal and the third message of the initiator UE and the reception of the second message, the response reference signal and the fourth message of each responder UE are repeated a certain number of times.

21. A method for locating an initiating user equipment (UE), the method being performed by a responding UE and comprising: The system receives a first message from the initiating UE, the first message including one or more characteristics of a transmission of a first reference signal of the initiating UE and one or more characteristics of a transmission of a second reference signal of the responding UE, wherein the responding UE is identified by the initiating UE from a plurality of UEs based on the responding UE's location attributes; sends a second message to the initiating UE, the second message confirming the receipt of the first message by the initiating UE; receives the first reference signal from the initiating UE based on the sending of the second message and according to the one or more characteristics of the transmission of the first reference signal; and sends the second reference signal to the initiating UE based on the receipt of the first reference signal and according to the one or more characteristics of the transmission of the second reference signal. The initiating UE receives a third message based on the transmission of the second reference signal, the third message including at least an indication that the initiating UE has received the second reference signal; and sends a fourth message to the initiating UE based on the reception of the third message from the initiating UE, the fourth message including timing data related to a departure time of the second reference signal and an arrival time of the first reference signal, and a location of the responding UE at the departure time of the second reference signal.

22. The method of claim 21, wherein the one or more characteristics of the transmission of the first reference signal include an identifier (ID) of the first reference signal, timing data associated with a time slot used by the initiating UE to transmit the first reference signal to the responding UE, and frequency data associated with a frequency used by the initiating UE to transmit the first reference signal to the responding UE.

23. The method according to claim 21, wherein the one or more characteristics of the transmission of the second reference signal include an identifier (ID) of the second reference signal and timing data associated with a time slot used by the responding UE to transmit the second reference signal to the initiating UE.

24. The method according to request item 23, wherein the second message further includes frequency data related to a frequency used by the responding UE to send the second reference signal to the initiating UE.

25. The method according to request item 21, wherein the reception of the first and third messages by the responder UE and the transmission of the second and fourth messages by the responder UE are performed using licensed spectrum.

26. The method according to request item 21, wherein the reception of the first reference signal and the transmission of the second reference signal by the responder UE are performed using unlicensed spectrum.

27. The method of request item 21, wherein the location attribute of the responder UE includes a direction in which the responder UE is moving, a location confidence of the responder UE, a speed of the responder UE, or a location of the responder UE, or a combination thereof.

28. According to the method of request item 27, wherein the location confidence of the responder UE is higher than the location confidence of the initiator UE.

29. The method of request item 27, wherein the initiator UE identifies the responder UE from the plurality of UEs based on the fact that the responder UE is moving in a direction different from the direction in which the initiator UE is moving.

30. A responder user equipment (UE) for wireless communication, the responder UE comprising: One transceiver; The memory; and one or more processors communicatively coupled to the memory and the transceiver, the one or more processors being configured to: receive a first message from an initiating UE, the first message including one or more characteristics of a transmission of a first reference signal of the initiating UE and one or more characteristics of a transmission of a second reference signal of the responding UE, wherein the responding UE is identified by the initiating UE from a plurality of UEs based on the responding UE's location attributes; send a second message to the initiating UE, the second message indicating at least an acknowledgment by the responding UE of receiving the first message from the initiating UE; receive the first reference signal from the initiating UE and based on sending the second message based on the one or more characteristics of the transmission of the first reference signal; send the second reference signal to the initiating UE and based on receiving the first reference signal based on the one or more characteristics of the transmission of the second reference signal. The initiating UE receives a third message based on the second reference signal, the third message including at least an indication that the initiating UE has received the second reference signal; and sends a fourth message to the initiating UE based on the receipt of the third message from the initiating UE, the fourth message including timing data related to a departure time of the second reference signal and an arrival time of the first reference signal, and a location of the responding UE at the departure time of the second reference signal.

31. The responder UE according to request item 30, wherein the one or more characteristics of the transmission of the first reference signal include an identifier (ID) of the first reference signal, timing data associated with a time slot used by the initiator UE to transmit the first reference signal to the responder UE, and frequency data associated with a frequency used by the initiator UE to transmit the first reference signal to the responder UE.

32. The respondent UE according to request item 30, wherein the one or more characteristics of the transmission of the second reference signal include the identifier (ID) of the second reference signal and timing data related to the time slot used by the respondent UE to transmit the second reference signal to the initiating UE.

33. The respondent UE according to request item 32, wherein the second message further includes frequency data related to the frequency used by the respondent UE to send the second reference signal to the initiating UE.

34. The respondent UE according to request item 30, wherein the first message and the third message are received by the respondent UE using a received spectrum, and wherein the second message and the fourth message are transmitted by the respondent UE using the licensed spectrum.

35. The respondent UE according to request item 30, wherein the first reference signal is received by the respondent UE using an unlicensed spectrum, and wherein the second reference signal is transmitted by the respondent UE using the unlicensed spectrum.

36. The respondent UE according to request item 30, wherein the location attribute of the respondent UE includes a direction in which the respondent UE is moving, a location confidence of the respondent UE, a speed of the respondent UE, or a location of the respondent UE, or a combination thereof.

37. The respondent UE according to request item 36, wherein the location confidence of the respondent UE is higher than the location confidence of the initiator UE.

38. The responder UE according to request item 36, wherein the initiator UE identifies the responder UE from the plurality of UEs based on the fact that the responder UE is moving in a direction different from the direction in which the initiator UE is moving.

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