Position estimation using mobile anchor

Abstract

The location of a target user equipment (UE) is determined using a set of Reference Signal Time Difference (RSTD) measurements, comprising at least three RSTD measurements generated by the target UE at different times. Each RSTD measurement is generated based on a Position Reference Signal (PRS) transmitted by a fixed anchor entity and a corresponding PRS transmitted by a mobile anchor entity. At least two anchor-to-anchor receive-to-transmit (RxTx) time difference measurements are generated by the anchor entities, wherein each anchor-to-anchor RxTx time difference measurement is associated with an RSTD measurement, and the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements. The location estimate of the target UE is determined based on this set of RSTD measurements and the at least two anchor-to-anchor RxTx time difference measurements.

Description

[Technical Field]

[0001] This patent application claims the benefit of International Application No. PCT / CN2021 / 119487 entitled “METHOD AND APPARATUS FOR POSITION ESTIMATION USING MOBILE ANCHOR”, filed on September 21, 2021, the entire contents of which are expressly incorporated herein by reference.

[0002] The subject matter disclosed herein is generally concerned with the field of wireless communications, and more specifically with technologies used to support positioning. [Previous Technology]

[0003] Wireless communication systems have undergone multiple generations of development, including first-generation analog wireless telephony (1G), second-generation (2G) digital wireless telephony (including temporary 2.5G and 2.75G networks), third-generation (3G) high-speed data, wireless services supporting the Internet, and fourth-generation (4G) services (e.g., Long Term Evolution (LTE) or WiMax). Currently, many different types of wireless communication systems are in use, including cellular and Personal Communication Services (PCS) systems. Known examples of cellular systems include the Cellular Analog Advanced Mobile Telephone System (AMPS) and digital cellular systems based on Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), and Time Division Multiple Access (TDMA), as well as the Global System for Mobile Communications (GSM).

[0004] The fifth-generation (5G) wireless standard, known as New Radio (NR), requires improvements such as higher data transmission speeds, more connections, and better coverage. The 5G standard, according to the Next Generation Mobile Networks Alliance, aims to provide tens of megabits per second (Mbps) of data to tens of thousands of users and 1 gigabit per second (Gbps) of data to dozens of employees on an office building floor. To support large-scale sensor deployments, it should support hundreds of thousands of simultaneous connections. Therefore, the spectral efficiency of 5G mobile communications should be significantly improved compared to the current 4G standard. Furthermore, signal transmission efficiency should be improved and latency should be significantly reduced compared to the current standard. [Summary of the Invention]

[0005] The location of a target user equipment (UE) is determined using a set of Reference Signal Time Difference (RSTD) measurements, which includes at least three RSTD measurements generated by the target UE at different times. Each RSTD measurement is generated based on a Position Reference Signal (PRS) transmitted by a fixed anchor entity and a corresponding PRS transmitted by a mobile anchor entity. At least two anchor-to-anchor receive-to-transmit (RxTx) time difference measurements are generated by the anchor entities, wherein each anchor-to-anchor RxTx time difference measurement is associated with an RSTD measurement, and the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements. The location estimate of the target UE is determined based on this set of RSTD measurements and at least two anchor-to-anchor RxTx time difference measurements.

[0006] In one embodiment, a method for operating a location estimation entity to determine the location of a target user equipment (UE) includes obtaining a set of reference signal time difference (RSTD) measurements of the target UE, including at least three RSTD measurements generated by the target UE at different times, wherein each RSTD measurement in the RSTD measurement set is generated using a location reference signal (PRS) from a first PRS instance group transmitted by a fixed anchor entity and a corresponding PRS from a second PRS instance group transmitted by a mobile anchor entity; obtaining at least two anchor-to-anchor receive-to-transmit (RxTx) time difference measurements, wherein each anchor-to-anchor RxTx time difference measurement is associated with a PRS from the first PRS instance group and a corresponding PRS from the second PRS instance group, wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the RSTD measurement set; and determining a location estimate of the target UE based on the RSTD measurement set and the at least two anchor-to-anchor RxTx time difference measurements.

[0007] In one embodiment, a location estimation entity configured to determine the location of a target user equipment (UE) includes a memory; at least one external interface; and at least one processor communicatively coupled to the memory and the at least one external interface, the at least one processor being configured to: obtain a set of reference signal time difference (RSTD) measurements of the target UE, including at least three RSTD measurements generated by the target UE at different times, wherein a location reference signal (PRS) from a first PRS instance group transmitted from a fixed anchor entity and a location reference signal from a mobile anchor entity are used. The corresponding PRS of the second PRS instance group is used to generate RSTD measurements for each of the RSTD measurement groups; at least two anchor-to-anchor receive-to-transmit (RxTx) time difference measurements are obtained, wherein each anchor-to-anchor RxTx time difference measurement is associated with a PRS from the first PRS instance group and a corresponding PRS from the second PRS instance group, wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the RSTD measurement group; and the location estimate of the target UE is determined based on the RSTD measurement group and the at least two anchor-to-anchor RxTx time difference measurements.

[0008] In one embodiment, a location estimation entity configured to determine the location of a target user equipment (UE) includes: a component for obtaining a set of reference signal time difference (RSTD) measurements of the target UE, including at least three RSTD measurements generated by the target UE at different times, wherein each RSTD measurement of the RSTD measurement set is generated using a positioning reference signal (PRS) from a first PRS instance group transmitted by a fixed anchor entity and a corresponding PRS from a second PRS instance group transmitted by a mobile anchor entity; a component for obtaining at least two anchor-to-anchor receive-to-transmit (RxTx) time difference measurements, wherein each anchor-to-anchor RxTx time difference measurement is associated with a PRS from the first PRS instance group and a corresponding PRS from the second PRS instance group, wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the RSTD measurement set; and a component for determining a location estimate of the target UE based on the RSTD measurement set and the at least two anchor-to-anchor RxTx time difference measurements.

[0009] In one embodiment, a non-transitory storage medium includes code stored thereon, the code being operable to configure at least one processor in a location estimation entity for determining the location of a target user equipment (UE), the code including instructions to: obtain a set of reference signal time difference (RSTD) measurements of the target UE, including at least three RSTD measurements generated by the target UE at different times, wherein a positioning reference signal (PRS) from a first PRS instance group transmitted by a fixed anchor entity and a location reference signal from a second PRS instance group transmitted by a mobile anchor entity are used. The corresponding PRS of the RS instance group is used to generate RSTD measurements for each of the RSTD measurement groups; at least two anchor-to-anchor receive-to-transmit (RxTx) time difference measurements are obtained, wherein each anchor-to-anchor RxTx time difference measurement is associated with a PRS from a first PRS instance group and a corresponding PRS from a second PRS instance group, wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the RSTD measurement group; and the location estimate of the target UE is determined based on the RSTD measurement group and the at least two anchor-to-anchor RxTx time difference measurements.

Implementation Method

[0027] The form of this application is provided in the following description and related drawings, and the related drawings involve various examples provided for illustrative purposes. Alternative forms may be designed without departing from the scope of this application. Furthermore, well-known elements of this application will not be described in detail or will be omitted to avoid obscuring the relevant details of this application.

[0028] The terms “exemplary” and / or “example” are used herein to mean “serving as an example, instance or illustration.” Any manner described herein as “exemplary” and / or “example” is not necessarily to be construed as superior to or better than other manners. Similarly, the term “manner of this case” does not require that all manner of this case include the features, advantages or modes of operation discussed.

[0029] Those skilled in the art will understand that any of a variety of different techniques and arts can be used to represent the information and signals described below. For example, data, instructions, commands, information, signals, bits, symbols and chips that may be referenced in the following description may be derived from voltage, current, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof, depending in part on the specific application, in part on the required design, and in part on the appropriate technology, etc.

[0030] Furthermore, various states are described according to sequences of actions performed, for example, by elements of a computing device. It will be appreciated that the various actions described herein can be performed by specific circuitry (e.g., an application-specific integrated circuit (ASIC)), program instructions executed by one or more processors, or a combination of both. Furthermore, the sequences of actions described herein can be considered entirely embodied in any form of non-transitory computer-readable storage medium storing a corresponding set of computer instructions that, when executed, will cause or instruct the processor of the associated device to perform the functions described herein. Therefore, the various states of this application can be embodied in a variety of different forms, all of which are considered to be within the scope of the claimed object. Furthermore, for each state of this application, the corresponding form of any such state can be described herein as, for example, "logic" "configured" to perform the described actions.

[0031] As used herein, unless otherwise stated, the terms “User Equipment” (UE) and “Base Station” are not intended to be specific to or otherwise limited to any particular Radio Access Technology (RAT). Generally, a UE can be any wireless communication device (e.g., mobile phone, router, tablet, laptop, consumer asset positioning device, wearable device (e.g., smartwatch, glasses, augmented reality (AR) / virtual reality (VR) headset, etc.), vehicle (e.g., car, motorcycle, bicycle, etc.), Internet of Things (IoT) device, etc.) used by a user to communicate over a wireless communication network. A UE can be mobile or can (e.g., at certain times) be stationary and can communicate with a Radio Access Network (RAN). As used herein, the term “UE” is interchangeably referred to as “Access Terminal” or “AT”, “Client Equipment”, “Wireless Equipment”, “User Equipment”, “User Terminal”, “Subscriber Station”, “User Terminal” or “UT”, “Mobile Equipment”, “Mobile Terminal”, “Mobile Station”, or variations thereof. Typically, a UE can communicate with the core network via the RAN, and via the core network, the UE can connect to external networks such as the Internet and other UEs. Of course, other mechanisms for the UE to connect to the core network and / or the Internet are also possible, such as via wired access networks, wireless local area network (WLAN) networks (e.g., based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard), etc.

[0032] The base station can operate according to one of several RATs for communicating with the UE, depending on the network in which it is deployed, and may be alternatively referred to as an Access Point (AP), Network Node, Node B, Evolved Node B (eNB), Next Generation eNB (ng-eNB), New Radio (NR) Node B (also known as gNB or g Node B), etc. The base station can primarily be used to support radio access by the UE, including supporting data, voice, and / or signal transmission connections for the supported UE. In some systems, the base station can provide purely edge node signal transmission, while in others it can provide additional control and / or network management functions. The communication link through which the UE can send signals to the base station is called an uplink (UL) channel (e.g., reverse transport channel, reverse control channel, access channel, etc.). The communication link through which the base station can send signals to the UE is called a downlink (DL) or forward link channel (e.g., paging channel, control channel, broadcast channel, forward transport channel, etc.). As used herein, the term Transport Channel (TCH) can refer to either the uplink / reverse or downlink / forward Transport Channel. Additionally, a communication link through which a UE can send signals to other UEs is called a Sidechain (SL) Channel.

[0033] The term "base station" can refer to a single physical transmit / receive point (TRP) or multiple physical TRPs, which may or may not be co-located. For example, when the term "base station" refers to a single physical TRP, the physical TRP may be the antenna of the base station corresponding to a cell (or several cell sectors) of the base station. When the term "base station" refers to multiple co-located physical TRPs, the physical TRP may be the antenna array of the base station (e.g., in a multiple-input multiple-output (MIMO) system or where the base station employs beamforming). When the term "base station" refers to multiple non-co-located physical TRPs, the physical TRP may be a distributed antenna system (DAS) (a spatially separated antenna network connected to a common source via a transmission medium) or a remote radio head (RRH) (a remote base station connected to a serving base station). Alternatively, a non-co-located physical TRP may be a serving base station receiving measurement reports from the UE and neighboring base stations where the UE is measuring its reference radio frequency (RF) signal. Since the TRP is the point from which a base station transmits and receives wireless signals, as used in this article, the reference for transmitting or receiving signals from a base station will be understood as referring to the specific TRP of the base station.

[0034] In some implementations that support UE positioning, the base station may not support radio access by the UE (e.g., it may not support the UE's data, voice, and / or signal transmission connections), but may instead transmit reference signals to the UE for measurement by the UE, and / or receive and measure signals transmitted by the UE. Such a base station may be referred to as a positioning beacon (e.g., when transmitting signals to the UE) and / or a location measurement unit (e.g., when receiving and measuring signals from the UE).

[0035] An "RF signal" includes electromagnetic waves of a given frequency that transmit information through space between a transmitter and a receiver. As used herein, a transmitter may send 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 can be referred to as a "multipath" RF signal.

[0036] Figure 1A illustrates an example wireless communication system 100 according to the present invention. The wireless communication system 100 (which may also be referred to as a wireless wide area network (WWAN)) may include various base stations 102 (labeled "BS") and various UEs 104. Base stations 102 may include macrocell base stations (high-power cellular base stations) and / or small cell base stations (low-power cellular base stations). In one embodiment, a macrocell base station may include an eNB and / or ng-eNB in ​​which the wireless communication system 100 corresponds to an LTE network, or a gNB in ​​which the wireless communication system 100 corresponds to an NR network, or a combination of both, and a small cell base station may include femtocells, picocells, microcells, etc.

[0037] Base station 102 can collectively form a RAN and interface with core network 170 (e.g., Evolved Packet Core (EPC) or 5G Core (5GC)) via backhaul link 122, and reach one or more additional location servers 172 (e.g., Location Management Function (LMF) or Secure User Plane Location (SUPL) Location Platform (SLP)) via core network 170. The (multiple) location servers 172 can be part of core network 170 or external to core network 170. Among other functions, base station 102 can perform one or more of the following related functions: transmitting user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, non-access stratum (NAS) message distribution, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS), user and device tracking, RAN information management (RIM), paging, location, and warning message delivery. Base stations 102 can communicate with each other directly or indirectly (e.g., via EPC / 5GC) via backhaul link 134, which can be wired or wireless.

[0038] Base station 102 can wirelessly communicate with UE 104. Each base station 102 can provide communication coverage for a corresponding geographic coverage area 110. In one configuration, one or more cells in each geographic coverage area 110 can be supported by base station 102. A "cell" is a logical communication entity used to communicate with a base station (e.g., on a certain frequency resource, referred to as a carrier frequency, component carrier, carrier, frequency band, or similar), and can be associated with an identifier used to distinguish cells operating via the same or different carrier frequencies (e.g., Physical Cell Identifier (PCI), Enhanced Cell Identifier (ECI), Virtual Cell Identifier (VCI), Cell Global Identifier (CGI), etc.). In some cases, different cells can be configured according to different protocol types (e.g., Machine Type Communication (MTC), Narrowband Internet of Things (NB-IoT), Enhanced Mobile Broadband (eMBB), or others), which can provide access for different types of UEs. Because cells are supported by specific base stations, the term "cell" can refer to one or both of the logical communication entity and the base station supporting it, depending on the context. In some cases, the term "cell" can also refer to the geographic coverage area (e.g., sector) of a base station, provided that the carrier frequency can be detected and used for communication within some portion of the geographic coverage area 110.

[0039] Although the geographic coverage areas 110 of adjacent macrocell base stations 102 may partially overlap (e.g., in a delivery area), some geographic coverage areas 110 may substantially overlap with larger geographic coverage areas 110. For example, a small cell base station 102' ("SC" labeled "small cell") may have a geographic coverage area 110' that substantially overlaps with the geographic coverage areas 110 of one or more macrocell base stations 102. A network including small cells and macrocell base stations may be referred to as a heterogeneous network. A heterogeneous network may also include a home eNB (HeNB) that can provide services to a restricted group called a Closed Subscriber Group (CSG).

[0040] The communication link 120 between base station 102 and UE 104 may include uplink (also known as reverse link) transmission from UE 104 to base station 102 and / or downlink (DL) (also known as forward link) transmission from base station 102 to UE 104. The communication link 120 may further include a sidechain channel 120', which can be used to directly connect multiple UEs 104, such as UE 104' illustrated in Figure 1A. The communication link 120 may use MIMO antenna technologies, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link 120 may be traversed via one or more carrier frequencies. Carrier allocation may be asymmetrical relative to the downlink and uplink (e.g., more or fewer carriers may be allocated to the downlink than to the uplink).

[0041] The wireless communication system 100 may also include a wireless local area network (WLAN) access point (AP) 150, which communicates with a WLAN station (STA) 152 via a communication link 154 in unlicensed spectrum (e.g., 5 GHz). When communicating in unlicensed spectrum, the WLAN STA 152 and / or WLAN AP 150 may perform a clear passage assessment (CCA) or listen-before-speak (LBT) procedure before communication to determine whether the channel is available.

[0042] The small cell base station 102' can operate in licensed and / or unlicensed spectrum. When operating in unlicensed spectrum, the small cell base station 102' can employ LTE or NR technology and use the same 5 GHz unlicensed spectrum as used by the WLAN AP 150. Employing LTE / 5G in unlicensed spectrum can enhance access network coverage and / or increase access network capacity. NR in unlicensed spectrum can be referred to as NR-U. LTE in unlicensed spectrum can be referred to as LTE-U, Licensed Assisted Access (LAA), or MulteFire.

[0043] The wireless communication system 100 may also include a millimeter-wave (mmW) base station 180, which can communicate with the UE 182 at millimeter-wave frequencies and / or near-millimeter-wave frequencies. Extremely high frequency (EHF) is a portion of the electromagnetic spectrum in the RF domain. The EHF band ranges from 30 GHz to 300 GHz, with wavelengths between 1 mm and 10 mm. Radio waves in this band are referred to as millimeter waves. Near-millimeter waves can extend down to frequencies of 3 GHz with wavelengths of 100 mm. The ultra-high frequency (SHF) band extends between 3 GHz and 30 GHz and is also referred to as centimeter waves. Communication using millimeter-wave / near-millimeter-wave RF bands has high path loss and relatively short range. The mmW base station 180 and the UE 182 can utilize beamforming (transmit and / or receive) on the mmW communication link 184 to compensate for the extremely high path loss and short range. Furthermore, it should be understood that in alternative configurations, one or more base stations 102 may also transmit using millimeter-wave or near-millimeter-wave and beamforming. Therefore, it should be understood that the foregoing description is merely an example and should not be construed as limiting the various states disclosed herein.

[0044] Transmit beamforming is a technique for focusing RF signals in a specific direction. Traditionally, when a network node (e.g., a base station) broadcasts an RF signal, it broadcasts the signal in all directions (omnidirectional). Using transmit beamforming, the network node determines the location of a given target device (e.g., a UE) (relative to the transmitting network node) and projects a stronger downlink RF signal in that specific direction, thereby providing a faster (in terms of data rate) and stronger RF signal to (multiple) receiving devices. To change the directivity of the RF signal during transmission, the network node can control the phase and relative amplitude of the RF signal at each of one or more transmitters broadcasting the RF signal. For example, the network node can use an array of antennas (referred to as a "phased array" or "antenna array") to build an RF beam that can be "steered" to point in different directions without actually moving the antennas. Specifically, RF currents from the transmitters are fed to the individual antennas with the correct phase relationship, causing the radio waves from the individual antennas to superimpose to increase radiation in the desired direction while canceling out to suppress radiation in the undesirable direction.

[0045] Transmit beams can be quasi-co-located, meaning they exhibit the same parameters to the receiver (e.g., UE), regardless of whether the transmit antennas of the network node itself are physically co-located. In NR, there are four quasi-co-location (QCL) relationships. Specifically, a given type of QCL relationship means that certain parameters about a second reference RF signal on a second beam can be derived from information about the source reference RF signal on the source beam. Therefore, if the source reference RF signal is QCL type A, the receiver can use the source reference RF signal to estimate the Doppler shift, Doppler spread, average delay, and delay spread of the second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL type B, the receiver can use the source reference RF signal to estimate the Doppler shift and Doppler spread of the second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL type C, the receiver can use the source reference RF signal to estimate the Doppler shift and average delay of the second reference RF signal transmitted on the same channel. If the source reference RF signal is of type QCL D, the receiver can use the source reference RF signal to estimate the spatial reception parameters of the second reference RF signal transmitted on the same channel.

[0046] In receive beamforming, a receiver uses a receive beam to amplify an RF signal detected on a given channel. For example, the receiver may increase the gain setting and / or adjust the phase setting of the antenna array in a particular direction to amplify (e.g., increase its gain level) the RF signal received from that direction. Therefore, when it is said that the receiver performs beamforming in a certain direction, this means that the beam gain in that direction is higher than the beam gain in other directions, or that the beam gain in that direction is the highest compared to the beam gain in all other directions available to the receiver. This results in a stronger received signal strength (e.g., reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-interference-plus-noise ratio (SINR), etc.) of the RF signal received from that direction.

[0047] The transmit and receive beams may be spatially related. Spatial relationship means that parameters for a second beam (e.g., transmit or receive beam) for a second reference signal can be derived from information about a first beam (e.g., receive beam or transmit beam) for a first reference signal. For example, a UE may use a specific receive beam to receive a reference downlink reference signal (e.g., synchronization signal block (SSB)) from a base station. The UE may then form a transmit beam for transmitting an uplink reference signal (e.g., sounding reference signal (SRS)) to that base station based on the parameters of the receive beam.

[0048] Please note that a "downlink" beam can be either a transmit beam or a receive beam, depending on the entity forming it. For example, if a base station is forming a downlink beam to transmit a reference signal to the UE, then the downlink beam is a transmit beam. However, if the UE is forming a downlink beam, then it is a receive beam to receive the downlink reference signal. Similarly, an "uplink" beam can be either a transmit beam or a receive beam, depending on the entity forming it. For example, if a base station is forming an uplink beam, then it is an uplink receive beam; if the UE is forming an uplink beam, then it is an uplink transmit beam.

[0049] In 5G, the spectrum in which wireless nodes (e.g., base stations 102 / 180, UEs 104 / 182) operate is divided into multiple frequency ranges: FR1 (from 450 to 6000 MHz), FR2 (from 24250 to 52600 MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). Millimeter wave bands typically include the FR2, FR3, and FR4 frequency ranges. Therefore, the terms "millimeter wave" and "FR2" or "FR3" or "FR4" are often used interchangeably.

[0050] In multi-carrier systems (such as 5G), one of the carrier frequencies is referred to as the "primary carrier," "anchor carrier," "primary serving cell," or "PCell," while the remaining carrier frequencies are referred to as "secondary carriers," "secondary serving cells," or "SCell." In carrier aggregation, the anchor carrier is the carrier operating on the primary frequency (e.g., FR1) utilized by UE 104 / 182, and the cell in which UE 104 / 182 performs the initial radio resource control (RRC) connection establishment procedure or initiates the RRC connection re-establishment procedure. The primary carrier carries all common and UE-specific control channels and can be a carrier on a licensed frequency (however, this is not always the case). The secondary carrier is a carrier operating on a second frequency (e.g., FR2), which can be configured once an RRC connection is established between UE 104 and the anchor carrier, and can be used to provide additional radio resources. In some cases, the secondary carrier can be a carrier on an unlicensed frequency. The secondary carrier may contain only the necessary signal transmission information and signals; for example, UE-specific information may not be present in the secondary carrier, since the primary uplink and downlink carriers are usually UE-specific. This means that different UEs 104 / 182 within a cell may have different downlink primary carriers. The same applies to the uplink primary carrier. The network can change the primary carrier of any UE 104 / 182 at any time. For example, this can be done to balance the load on different carriers. Because a "serving cell" (whether PCell or SCell) corresponds to the carrier frequency / component carrier that a base station is communicating on, the terms "cell," "serving cell," "component carrier," "carrier frequency," and similar terms can be used interchangeably.

[0051] For example, still referring to Figure 1A, one of the frequencies used by the macrocell base station 102 may be an anchor carrier (or "PCell") and other frequencies 180 used by the macrocell base station 102 and / or the mmW base station may be subcarriers ("SCell"). Simultaneous transmission and / or reception on multiple carriers enables the UE 104 / 182 to significantly increase its data transmission and / or reception rates. For example, compared to a single 20 MHz carrier, two aggregated 20 MHz carriers in a multicarrier system theoretically result in a doubling of the data rate (i.e., 40 MHz).

[0052] The wireless communication system 100 may also include a UE 164, which can communicate with the macrocell base station 102 via communication link 120 and / or with the mmW base station 180 via mmW communication link 184. For example, the macrocell base station 102 may support PCells and one or more SCells for the UE 164, and the mmW base station 180 may support one or more SCells for the UE 164.

[0053] In the example of Figure 1A, one or more Earth Orbit Satellite Positioning System (SPS) spacecraft (SV) 112 (e.g., satellites) can be used as an independent source of location information for any of the illustrated UEs (shown as a single UE 104 in Figure 1A for simplicity). UE 104 may include one or more dedicated SPS receivers specifically designed to receive SPS signal 124 in order to obtain geographic location information from SV 112. SPS typically includes a transmitter system (e.g., SV 112) positioned such that a receiver (e.g., UE 104) can determine its location on or above the Earth based at least in part on signals received from the transmitter (e.g., SPS signal 124). Such a transmitter typically transmits a signal with a set number of repeating pseudo-random noise (PN) codes marked on a chip. Although typically located in SV 112, the transmitter may sometimes be located at a ground control station, base station 102, and / or other UE 104.

[0054] The use of the SPS signal 124 can be enhanced via various satellite-based augmentation systems (SBAS), which may be associated with or otherwise enabled by one or more global and / or regional navigation satellite systems. For example, SBAS may include augmentation systems(s) that provide integrity information, differential correction, etc., such as Wide Area Augmentation System (WAAS), European Geostationary Navigation Overlap Service (EGNOS), Multifunctional Satellite Augmentation System (MSAS), Global Positioning System (GPS) Assisted Geo-Augmented Navigation or GPS and Geo-Augmented Navigation System (GAGAN), and / or similar. Therefore, as used herein, an SPS may include any combination of one or more global and / or regional navigation satellite systems and / or augmentation systems, and the SPS signal 124 may include an SPS, an SPS class, and / or other signals associated with such one or more SPSs.

[0055] The wireless communication system 100 may further include one or more UEs (such as UE 190) indirectly connected to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links. In the example of Figure 1A, UE 190 has a D2D P2P link 192, in which one of UEs 104 is connected to one of base stations 102 (e.g., UE 190 can indirectly obtain cellular connectivity through it), and a D2D P2P link 194, in which a WLAN STA 152 is connected to a WLAN AP 150 (UE 190 can indirectly obtain WLAN-based internet connectivity through it). In the example, D2D P2P links 192 and 194 may be supported by any well-known D2D RAT, such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), Bluetooth®, etc.

[0056] Figure 1B illustrates an architecture diagram of an NG-RAN node (e.g., base station 102), which may be within the NG-RAN shown in Figure 1A, for example, as a separate entity or as part of another gNB. According to one implementation, base station 102 may be gNB 109. For example, the architecture shown in Figure 1B can be applied to any gNB 109 in Figure 1A.

[0057] As shown in the figure, gNB 109 may include gNB Central Unit (gNB-CU) 103, gNB Distributed Unit (gNB-DU) 105-DU, and gNB Remote Unit (gNB-RU) 105-RU, which may be physically located within gNB 109 or physically separated. gNB-CU 103 is a logical or physical node that carries support for Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), and Packet Data Convergence Protocol (PDCP) protocols for gNB 109 used on the NR Uu interfacing, and controls the operation of one or more gNB-DUs and / or gNB-RUs. gNB-CU 103 terminates the F1 interface connected to the gNB-DU, and in some implementations terminates the F1 interface connected to the gNB-RU. As shown in the figure, gNB-CU 103 may communicate with AMF via the NG interface. The gNB-CU 103 can also communicate with one or more other gNB 109s via the Xn interface. The gNB-DU 105-DU is a logical or physical node carrying support for the Radio Link Control (RLC), Media Access Control (MAC), and Physical (PHY) protocol layers used on the NR Uu air interface of the gNB 109, and its operation is partially controlled by the gNB-CU 103. The gNB-DU terminates the F1 interface connected to the gNB-CU 103 and can also terminate the lower layer partitioning point interface Fx of the gNB-RU. The gNB-RU 105-RU can be based on lower layer functional partitioning and is a logical or physical node carrying support for lower layer functions, such as the PHY and Radio Frequency (RF) protocol layers used on the NR Uu air interface of the gNB 109, and its operation is partially controlled by the gNB-CU 103 and / or the gNB-DU 105-DU. The gNB-RU 105-RU terminates the Fx interface connected to the gNB-DU 105-DU, and in some implementations, the F1 interface connected to the gNB-CU 103 can be terminated.

[0058] gNB-CU 103 requests positioning measurements (e.g., E-CID) from gNB-DU 105-DU and / or gNB-RU 105-RU. gNB-DU 105-DU and / or gNB-RU 105-RU can report the measurements back to gNB-CU 103. gNB-DU 105-DU or gNB-RU 105-RU may include positioning measurement functionality. It should be understood that individual measurement nodes are not excluded.

[0059] Furthermore, as shown in Figure 1B, gNB 109 may include a transmitting point (TP) 107 and a receiving point (RP) 108, which together form a transmit-receive point (TRP) 106, which may be physically or logically located within gNB 109. gNB-CU 103 may be configured to communicate with TP 107 and RP 108, for example, via an F1 interface. Therefore, gNB-CU 103 controls one or more TP 107 and RP 108 that can be accessed from gNB-CU 103 via the F1 interface.

[0060] In some embodiments, base station 102 (or gNB 109) may include a subset of the elements shown in Figure 1B. For example, NG-RAN node 102 may include gNB-CU 103, but may not include one or more of gNB-DU 105-DU and gNB-RU 105-RU, RP 108, or TP 107. Alternatively, base station 102 may include one or more of gNB-DU 105-DU and RP 108 or TP 107, but may not include gNB-RU 105-RU. Furthermore, the elements shown in Figure 1B may be logically separate but physically co-located, or may be partially or completely physically separate. For example, one or more of gNB-DU 105-DU and / or gNB-RU 105-RU, RP 108, or TP 107 can be separate from or combined with the gNB-CU 103 entity. In the case of entity separation, the F1 or Fx interface can define signal transmission on the entity link or connection between the two separated elements. In some implementations, gNB-CU 103 can be divided into a control plane portion (referred to as CU-CP or gNB-CU-CP) and a user plane portion (referred to as CU-UP or gNB-CU-UP). In this case, both gNB-CU-CP and gNB-CU-UP can interact with gNB-DU 105-DU and / or gNB-RU 105-RU to support NR Uu space interface signal transmission in the control plane and user plane, respectively. However, only gNB-CU-CP can interact with TP 107 and RP 108 to support and control location-related communications.

[0061] The protocol layering between gNB-CU 103 and TP 107 and RP 108 can be based on F1 C as defined in 3GPP TS 38.470, which uses the top-level F1 Application Protocol (F1AP) specified in 3GPP TS 38.473. New location-supporting messages can be added directly to F1AP, or can be introduced into new location-specific protocols that use F1AP for transmission.

[0062] The location procedures with gNB-CU 103 can include all location-related procedures on the NG, Xn, and NR Uu interfaces. For example, the location procedure between AMF and base station 102 can use NGAP. The location procedure between base station 102 and other NG-RAN nodes (e.g., gNB 109) can use XnAP or protocols above XnAP, such as the Extended NR Location Protocol A (NRPPa) as defined in 3GPP TS 38.455. The location procedure between base station 102 and UE 104 can use RRC and / or LPP.

[0063] Corresponding messages used to support positioning can be carried within a transparent F1AP message transmission container. For example, the transmission of NGAP location reporting control and NAS transmission messages can be performed in UL / DL NGAP message transmission. The transmission of location-related XnAP messages can be performed in UL / DL XnAP message transmission. The transmission of location-related RRC (LPP) messages can be performed in UL / DL RRC (LP) message transmission.

[0064] Figure 2A illustrates an example wireless network architecture 200. For example, the 5GC 210 (also known as the Next Generation Core (NGC)) can be functionally considered as a control plane (C plane) function 214 (e.g., UE registration, authentication, network access, gateway selection, etc.) and a user plane (U plane) function 212 (e.g., UE gateway function, data network access, IP routing, etc.), which work together to form the core network. The user plane interface (NG-U) 213 and the control plane interface (NG-C) 215 connect the gNB 222 to the 5GC 210, specifically to the user plane function 212 and the control plane function 214, respectively. In an additional configuration, the ng-eNB 224 can also be connected to the 5GC 210 via the NG-C 215 to the control plane function 214, and to the user plane function 212 via the NG-U 213. Furthermore, the ng-eNB 224 can communicate directly with the gNB 222 via the backhaul connection 223. In some configurations, the next-generation RAN (NG-RAN) 220 may have one or more gNBs 222, while other configurations include one or more of both the ng-eNB 224 and the gNB 222. The gNB 222 or the ng-eNB 224 (or both) can communicate with one or more UEs 204 (e.g., any UE described herein).

[0065] Another alternative configuration may include one or more location servers 230a, 230b (sometimes collectively referred to as location server 230) (which may correspond to location server 172), which may communicate with control plane function 214 and user plane function 212 in 5GC 210 respectively to provide location assistance to (multiple) UEs 204. Location server 230 may be implemented as a plurality of separate servers (e.g., a physical server, different software modules on a single server, different software modules distributed across multiple physical servers, etc.), or alternatively, each server may correspond to a single server. Location server 230 may be configured to support one or more location services of UE 204, which may be connected to location server 230 via the core network, 5GC 210 and / or via the Internet (not shown). In addition, the location server 230 can be integrated into the core network components, or alternatively can be outside the core network, or alternatively can be outside the core network (e.g., a third-party server, such as an original equipment manufacturer (OEM) server or a service server).

[0066] Figure 2B illustrates another example wireless network architecture 250. For example, the 5GC 260 (also referred to as "NGC") can be functionally considered as a control plane function, provided by Access and Mobility Management Function (AMF) 264, User Plane Function (UPF) 262, Communication Period Management Function (SMF) 266, SLP 268, and LMF 270, which coordinate their operation to form the core network (i.e., 5GC 260). The user plane interface 263 and the control plane interface 265 connect the ng-eNB 224 to the 5GC 260 and specifically to the UPF 262 and AMF 264, respectively. In an additional configuration, the gNB 222 can also connect to the 5GC 260 via the control plane interface 265 to the AMF 264, and to the UPF 262 via the user plane interface 263. Furthermore, eNB 224 can communicate directly with gNB 222 via backhaul connection 223, with or without a direct gNB-to-5GC 260 connection. In some configurations, the new RAN 220 may have only one or more gNBs 222, while other configurations include one or more of both ng-eNB 224 and gNB 222. One of the gNB 222 or eNB 224 can communicate with UE 204 (e.g., any UE illustrated in Figure 1A). The base station of the new RAN 220 communicates with AMF 264 via the N2 interface and with UPF 262 via the N3 interface.

[0067] The AMF's functions include registration management, connection management, reachability management, mobility management, lawful interception, transmission of Communication Period Management (SM) messages between UE 204 and SMF 266, transparent proxy service for routing SM messages, access authentication and access authorization, transmission of SMS service messages between UE 204 and the SMS Service Function (SMSF) (not shown), and the Security Anchor Function (SEAF). The AMF also interacts with the Authentication Server Function (AUSF) (not shown) and UE 204, and receives the intermediate key established as a result of the UE 204 authentication process. In the case of UMTS (Universal Mobile Telecommunications System) User Identity Module (USIM)-based authentication, the AMF retrieves security material from the AUSSF. The AMF's functions also include Security Context Management (SCM). The SCM receives a key from the SEAF for exporting network-specific access keys. The AMF's functions also include location service management for regulatory services, transmission of location service messages between UE 204 and Location Management Function (LMF) 270 (which may correspond to Location Server 172) and between the new RAN 220 and LMF 270, allocation of Evolved Packet System (EPS) bearer identifiers for interoperability with EPS, and UE 204 mobility event notification. Furthermore, the AMF also supports functions for non-3GPP access networks.

[0068] The functions of the UPF include acting as an anchor point for intra-RAT / inter-RAT mobility (where applicable), acting as an external protocol data unit (PDU) communication point interconnected with the data network (not shown), providing packet routing and forwarding, packet inspection, user plane policy rule enforcement (e.g., gating, redirection, traffic redirection), lawful interception (user plane collection), traffic usage reporting, user plane quality of service (QoS) processing (e.g., UL / DL rate enforcement, reflective QoS marking in DL), UL traffic verification (service data flow (SDF) to QoS flow mapping), transport-level packet marking in UL and DL, DL packet buffering and DL data notification triggering, and sending and forwarding one or more "end markers" to the source RAN node.

[0069] The functions of SMF 266 include communication period management, UE Internet Protocol (IP) address allocation and management, selection and control of user plane functions, flow control configuration at UPF to route traffic to the correct destination, QoS enforcement of control policies, and downlink data notification. The communication interface between SMF 266 and AMF 264 is called the N11 interface.

[0070] Another alternative configuration may include an LMF 270, which can communicate with the 5GC 260 to provide location assistance to the UE 204. The LMF 270 may be implemented as a plurality of separate servers (e.g., a physical server, different software modules on a single server, different software modules distributed across multiple physical servers, etc.), or alternatively, each may correspond to a single server. The LMF 270 may be configured to support one or more location services for the UE 204, and may be connected to the LMF 270 via the core network, the 5GC 260, and / or via the Internet (not shown).

[0071] Figures 3A, 3B, and 3C illustrate several example components (represented by corresponding blocks) that may be incorporated into UE 302 (which may correspond to any UE described herein), base station 304 (which may correspond to any base station described herein), and network entity 306 (which may correspond to or embody any network function described herein, including location server 230 and LMF 270, or alternatively may be independent of the NG-RAN 220 and / or 5GC 210 / 260 infrastructure illustrated in Figures 2A and 2B, such as a private network) to support file transfer operations as taught herein. It should be understood that such components may be implemented in different types of devices in different implementations (e.g., in an ASIC, in a system-on-a-chip (SoC), etc.). The illustrated elements may also be incorporated into other devices in a communication system. For example, other devices in the system may include components similar to those described to provide similar functionality. Furthermore, a given device may contain one or more components. For example, the device may include multiple transceiver components that enable the device to operate on multiple carriers and / or communicate via different technologies.

[0072] UE 302 and base station 304 each include at least one wireless wide area network (WWAN) transceiver 310 and 350, providing components (e.g., transmitting components, receiving components, measurement components, tuning components, transmission avoidance components, etc.) for communication via one or more wireless communication networks (not shown) (such as NR networks, LTE networks, GSM networks, and / or similar). WWAN transceivers 310 and 350 may be connected to one or more antennas 316 and 356, respectively, for communication with other network nodes (such as other UEs, access points, base stations (e.g., eNB, gNB)) via at least one designated RAT (e.g., NR, LTE, GSM, etc.) on a set of time / frequency resources in a particular spectrum of interest. WWAN transceivers 310 and 350 may be configured differently to transmit and encode signals 318 and 358 (e.g., messages, indications, information, etc.) respectively, and conversely, to receive and decode signals 318 and 358 (e.g., messages, indications, information, boot signals, etc.) respectively, according to a specified RAT. Specifically, WWAN transceivers 310 and 350 include one or more transmitters 314 and 354 for transmitting and encoding signals 318 and 358 respectively, and one or more receivers 312 and 352 for receiving and decoding signals 318 and 358 respectively.

[0073] UE 302 and base station 304 also include at least one short-range radio transceiver 320 and 360, respectively, in at least some cases. The short-range radio transceivers 320 and 360 may be connected to one or more antennas 326 and 366, respectively, and provide components (e.g., transmitting components, receiving components, measuring components, tuning components, and transmission avoidance components, etc.) for communication with other network nodes (such as other UEs, access points, base stations, etc.) via at least one designated RAT (e.g., WiFi, LTE-D, Bluetooth®, Zigbee®, Z-Wave®, PC5, Dedicated Short Range Communication (DSRC), Vehicle Environment Radio Access (WAVE), Near Field Communication (NFC), etc.) through a wireless communication medium of interest. Short-range wireless transceivers 320 and 360 may be configured differently to transmit and encode signals 328 and 368 (e.g., messages, indications, information, etc.) respectively, and conversely, to receive and decode signals 328 and 368 (e.g., messages, indications, information, boot signals, etc.) respectively, according to a specified RAT. Specifically, short-range wireless transceivers 320 and 360 include one or more transmitters 324 and 364 for transmitting and encoding signals 328 and 368 respectively, and one or more receivers 322 and 362 for receiving and decoding signals 328 and 368 respectively. As specific examples, short-range wireless transceivers 320 and 360 may be WiFi transceivers, Bluetooth® transceivers, Zigbee® and / or Z-Wave® transceivers, NFC transceivers, or vehicle-to-vehicle (V2V) and / or vehicle-to-everything (V2X) transceivers.

[0074] A transceiver circuit including at least one transmitter and at least one receiver may, in some embodiments, include an integrated device (e.g., transmitter and receiver circuitry implemented as a single communication device), in some embodiments, include separate transmitter and separate receiver devices, or may be implemented in other ways in other embodiments. In one embodiment, the transmitter may include or be coupled to a plurality of antennas (e.g., antennas 316, 326, 356, 366), such as an antenna array, which allows the respective device to perform transmit "beamforming," as described herein. Similarly, the receiver may include or be coupled to a plurality of antennas (e.g., antennas 316, 326, 356, 366), such as an antenna array, which allows the respective device to perform receive beamforming, as described herein. In one embodiment, the transmitter and receiver may share the same plurality of antennas (e.g., antennas 316, 326, 356, 366), such that the respective device can only receive or transmit at a given time, rather than simultaneously receiving and transmitting. The wireless communication equipment of UE 302 and / or base station 304 (e.g., one or both of transceivers 310 and 320 and / or 350 and 360) may also include a network eavesdropping module (NLM) or similar for performing various measurements.

[0075] UE 302 and base station 304 also include, at least in some cases, satellite positioning system (SPS) receivers 330 and 370. SPS receivers 330 and 370 may be connected to one or more antennas 336 and 376, respectively, and may be provided with components for receiving and / or measuring SPS signals 338 and 378, such as Global Positioning System (GPS) signals, Global Navigation Satellite System (GLONASS) signals, Galileo signals, BeiDou signals, Indian Regional Navigation Satellite System (NAVIC), Quasi-Zenith Satellite System (QZSS) signals, etc. SPS receivers 330 and 370 may include any suitable hardware and / or software for receiving and processing SPS signals 338 and 378, respectively. SPS receivers 330 and 370 appropriately request information and operations from other systems and perform necessary calculations to determine the positions of UE 302 and base station 304 using measurements obtained via any suitable SPS algorithm.

[0076] Base station 304 and network entity 306 each include at least one network interface 380 and 390, providing components for communicating with other network entities (e.g., transmitting components, receiving components, etc.). For example, network interfaces 380 and 390 (e.g., one or more network access ports) may be configured to communicate with one or more network entities via a wired or wireless backhaul connection. In some embodiments, network interfaces 380 and 390 may be implemented as transceivers configured to support wired or wireless signal-based communication. For example, this communication may involve sending and receiving messages, parameters, and / or other types of information.

[0077] In one configuration, at least one WWAN transceiver 310 and / or at least one short-range wireless transceiver 320 may form the (wireless) communication interface of UE 302. Similarly, at least one WWAN transceiver 350, at least one short-range wireless transceiver 360, and / or at least one network interface 380 may form the (wireless) communication interface of base station 304. Likewise, at least one network interface 390 may form the (wireless) communication interface of network entity 306. Various wireless transceivers (e.g., transceivers 310, 320, 350, and 360) and wired transceivers (e.g., network interfaces 380 and 390) may generally be characterized as at least one transceiver, or alternatively at least one communication interface. Therefore, one can infer from the type of communication performed that a particular transceiver or communication interface is associated with a wired or wireless transceiver or communication interface (e.g., load communication between network devices or servers is typically associated with signal transmission via at least one wired transceiver).

[0078] UE 302, base station 304, and network entity 306 may also include other components that can be used in conjunction with the operations disclosed herein. UE 302, base station 304, and network entity 306 each include at least one processor 332, 384, and 394 for providing functions related to, for example, wireless communication, and for providing other processing functions. Thus, processors 332, 384, and 394 can provide processing components, such as determining components, calculating components, receiving components, transmitting components, indicating components, etc. In one embodiment, processors 332, 384, and 394 may include, for example, at least one general-purpose processor, multi-core processor, central processing unit (CPU), ASIC, digital signal processor (DSP), field-programmable gate array (FPGA), other programmable logic device or processing circuitry, or various combinations thereof.

[0079] UE 302, base station 304, and network entity 306 each include storage circuitry implementing memory components 340, 386, and 396 (e.g., each including a memory device) for maintaining information (e.g., information indicating reserved resources, thresholds, parameters, etc.). Therefore, memory components 340, 386, and 396 can provide storage components, retrieval components, maintenance components, etc. In some cases, UE 302, base station 304, and network entity 306 may each include PRS modules 342, 388, and 398. PRS modules 342, 388, and 398 may be hardware circuitry, which are respectively part of or coupled to processors 332, 384, and 394, and when executed, cause UE 302, base station 304, and network entity 306 to perform the functions described herein. In other configurations, PRS modules 342, 388, and 398 may be external to processors 332, 384, and 394 (e.g., part of a modem processing system, integrated with another processing system, etc.). Alternatively, PRS modules 342, 388, and 398 may be memory modules stored respectively in memory components 340, 386, and 396, which, when executed by processors 332, 384, and 394 (or a modem processing system, another processing system, etc.), cause UE 302, base station 304, and network entity 306 to perform the functions described herein. Figure 3A illustrates possible locations for PRS module 342, such as it may be part of at least one WWAN transceiver 310, memory component 340, at least one processor 332, or any combination thereof, or it may be a standalone component. Figure 3B illustrates possible locations of the PRS module 388, such as it may be part of at least one WWAN transceiver 350, memory component 386, at least one processor 384, or any combination thereof, or it may be a standalone component. Figure 3C illustrates possible locations of the PRS module 398, such as it may be part of at least one or more network interfaces 390, memory component 396, at least one processor 394, or any combination thereof, or it may be a standalone component.

[0080] UE 302 may include one or more sensors 344 coupled to at least one processor 332 to provide motion sensing or detection of motion and / or orientation information independent of motion data derived from signals received by at least one WWAN transceiver 310, at least one short-range wireless transceiver 320, and / or SPS receiver 330. For example, the sensors 344 may include accelerometers (e.g., microelectromechanical systems (MEMS) devices), gyroscopes, geomagnetic sensors (e.g., compasses), altimeters (e.g., barometric altimeters), and / or any other type of motion detection sensor. Furthermore, the sensors 344 may include a plurality of different types of devices and combine their outputs to provide motion information. For example, the sensors 344 may use a combination of multi-axis accelerometers and orientation sensors to provide the ability to calculate position in a two-dimensional (2D) and / or three-dimensional (3D) coordinate system.

[0081] In addition, UE 302 includes a user interface 346, providing components for providing instructions to the user (e.g., audio and / or visual instructions) and / or receiving user input (e.g., after the user actuates a sensing device, such as a keyboard, touch screen, microphone, etc.). Although not illustrated, base station 304 and network entity 306 may also include a user interface.

[0082] Referring more specifically to at least one processor 384, in the downlink, IP packets from network entity 306 can be provided to at least one processor 384. At least one processor 384 can implement functions for the RRC layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, and Media Access Control (MAC) layer. At least one processor 384 may provide RRC layer functions associated with broadcasting system information (e.g., Master Information Block (MIB), System Information Block (SIB)), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), measurement configuration of RAT inter-mobility and UE measurement reports; PDCP layer functions associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and delivery support functions; RLC layer functions associated with transmission of upper-layer PDUs, error correction via Automatic Repeat Request (ARQ), concatenation, segmentation and reassembly of RLC Service Data Units (SDUs), resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, scheduling information reporting, error correction, priority processing, and logical channel priority.

[0083] Transmitter 354 and receiver 352 can implement Layer 1 (L1) functions associated with various signal processing functions. Layer 1 (including the physical (PHY) layer) can include error detection on the transmission channel, forward error correction (FEC) encoding / decoding of the transmission channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. Transmitter 354 processes the mapping to the signal cluster based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The encoded and modulated symbols can then be divided into parallel streams. Each stream can then be mapped to an orthogonal frequency division multiplexing (OFDM) subcarrier, multiplexed with a reference signal (e.g., a pilot frequency) in the time and / or frequency domains, and then combined using inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time-domain OFDM symbol stream. The OFDM symbol stream is spatially precoded to generate multiple spatial streams. Channel estimates from the channel estimator are used to determine the coding and modulation scheme, as well as for spatial processing. Channel estimates can be derived from reference signals and / or channel conditions fed back from UE 302. Each spatial stream can then be provided to one or more different antennas 356. Transmitter 354 can modulate an RF carrier with the corresponding spatial stream for transmission.

[0084] At UE 302, receiver 312 receives signals via its corresponding antenna 316. Receiver 312 recovers the information modulated onto the RF carrier and provides this information to at least one processor 332. Transmitter 314 and receiver 312 implement Layer 1 functions associated with various signal processing functions. Receiver 312 can perform spatial processing on the information to recover any spatial stream destined for UE 302. If the destination of multiple spatial streams is UE 302, they can be combined by receiver 312 into a single OFDM symbol stream. Receiver 312 then uses a Fast Fourier Transform (FFT) to convert the OFDM symbol stream from the time domain to the frequency domain. The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. Symbols and reference signals on each subcarrier are recovered and demodulated by determining the most probable signal clustering point transmitted by base station 304. These soft decisions can be based on channel estimates calculated by a channel estimator. The soft decision is then decoded and deinterleaved to recover the data and control signals originally transmitted by base station 304 on the physical channel. The data and control signals are then provided to at least one processor 332 implementing Layer 3 (L3) and Layer 2 (L2) functions.

[0085] In the uplink, at least one processor 332 provides demultiplexing, packet reassembly, decryption, header decompression, and control signal processing between the transmission and logical channels to recover IP packets from the core network. At least one processor 332 is also responsible for error detection.

[0086] Similar to the functions described in the downlink transmission description of base station 304, at least one processor 332 provides RRC layer functions associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functions associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functions associated with transmission of upper-layer PDUs, error correction via ARQ, concatenation, segmentation and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs to transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction via Hybrid Automatic Repeat Request (HARQ), priority processing, and logical channel prioritization.

[0087] The reference signal transmitted from base station 304 by the channel estimator or the channel estimate fed back can be used by transmitter 314 to select an appropriate coding and modulation scheme and facilitate spatial processing. The spatial stream generated by transmitter 314 can be provided to different (multiple) antennas 316. Transmitter 314 can modulate an RF carrier with the corresponding spatial stream for transmission.

[0088] Uplink transmissions at base station 304 are processed in a manner similar to that described in conjunction with the receiver function at UE 302. Receiver 352 receives signals via its respective antenna(s) 356. Receiver 352 recovers the information modulated onto the RF carrier and provides that information to at least one processor 384.

[0089] In the uplink, at least one processor 384 provides demultiplexing, packet reassembly, decryption, header decompression, and control signal processing between the transport and logical channels to recover IP packets from the UE 302. IP packets from at least one processor 384 can be provided to the core network. At least one processor 384 is also responsible for error detection.

[0090] For convenience, UE 302, base station 304, and / or network entity 306 are illustrated in Figures 3A to 3C as including various components that can be configured according to various instances described herein. However, it should be understood that the illustrated components may have different functions in different designs. In particular, although the operation of computing devices typically requires some components (e.g., memory and processor components), other various components in Figures 3A to 3C are optional and can vary depending on the implementation. For example, in the case of Figure 3A, a particular implementation of UE 302 may omit (multiple) WWAN transceivers 310 (e.g., wearable devices, tablets, PCs, or laptops may have Wi-Fi and / or Bluetooth capabilities but no cellular capabilities), or (multiple) short-range transceivers 320 (e.g., cellular only, etc.), or (multiple) SPS receivers 330, or (multiple) sensors 344, etc. In another instance, in the case of Figure 3B, a particular implementation of base station 304 may omit (multiple) WWAN transceivers 350 (e.g., Wi-Fi AP hotspots without cellular capability), or (multiple) short-range wireless transceivers 360 (e.g., cellular only), or (SPS receiver 370), and so on.

[0091] Various components of UE 302, base station 304, and network entity 306 can communicate with each other via data buses 334, 382, ​​and 392, respectively. In one configuration, data buses 334, 382, ​​and 392 can form or be part of the communication interface for UE 302, base station 304, and network entity 306, respectively. For example, when different logical entities are embodied in the same device (e.g., incorporating gNB and location server functions of the same base station 304), data buses 334, 382, ​​and 392 can provide communication between them.

[0092] The components of Figures 3A to 3C can be implemented in various ways. In some implementations, the components of Figures 3B to 3C can be implemented in one or more circuits, such as, for example, one or more processors and / or one or more ASICs (which may include one or more processors). Here, each circuit may use and / or incorporate at least one memory component to store information or executable code used by the circuit to provide the function. For example, some or all of the functions represented by blocks 310 to 346 can be implemented by the processor and(multiple) memory components of UE 302 (e.g., by executing appropriate code and / or by appropriate configuration of the processor components). Similarly, some or all of the functions represented by blocks 350 to 388 can be implemented by the processor and(multiple) memory components of base station 304 (e.g., by executing appropriate code and / or by appropriate configuration of the processor components). Furthermore, some or all of the functions represented by blocks 390 to 398 can be implemented by the processor and (multiple) memory components of network entity 306 (e.g., by executing appropriate code and / or by appropriate configuration of the processor components). For simplicity, various operations, actions, and / or functions are described herein as being performed "by the UE," "by the base station," "by the network entity," etc. However, as will be understood, such operations, actions, and / or functions can actually be performed by specific components or combinations of components of UE 302, base station 304, network entity 306, etc., such as processors 332, 384, 394, transceivers 310, 320, 350 and 360, memory components 340, 386 and 396, PRS modules 342, 388 and 398, etc.

[0093] In some designs, network entity 306 may be implemented as a core network component. In other designs, network entity 306 may operate differently from the network service provider or cellular network infrastructure (e.g., NG RAN 220 and / or 5GC 210 / 260). For example, network entity 306 may be a component of a private network that may be configured to communicate with UE 302 via base station 304 or independently of base station 304 (e.g., via a non-cellular communication link, such as WiFi).

[0094] Various frame structures can be used to support downlink and uplink transmissions between network nodes (e.g., base stations and UEs). Figure 4A is Figure 400 illustrating an example of a downlink frame structure according to the present invention. Figure 4B is Figure 430 illustrating an example of a channel within a downlink frame structure according to the present invention. Figure 4C is Figure 450 illustrating an example of an uplink frame structure according to the present invention. Figure 4D is Figure 480 illustrating an example of a channel within an uplink frame structure according to the present invention. Other wireless communication technologies may have different frame structures and / or different channels.

[0095] LTE (and in some cases NR) uses OFDM on the downlink and single-carrier frequency division multiplexing (SC-FDM) on the uplink. However, unlike LTE, NR can also choose to use OFDM on the uplink. OFDM and SC-FDM divide the system bandwidth into multiple (K) orthogonal subcarriers, which are often referred to as tones, bins, etc. Each subcarrier can be modulated with data. Typically, the modulation symbols are transmitted using OFDM in the frequency domain and SC-FDM in the time domain. The gap between adjacent subcarriers can be fixed, and the total number of subcarriers (K) can depend on the system bandwidth. For example, the gap between subcarriers can be 15 kHz, and the minimum resource configuration (resource block) can be 12 subcarriers (or 180 kHz). Therefore, for system bandwidths of 1.25, 2.5, 5, 10, or 20 MHz, the nominal FFT size may be equal to 128, 256, 512, 1024, or 2048, respectively. The system bandwidth can also be divided into sub-bands. For example, a sub-band can cover 1.08 MHz (i.e., 6 resource blocks), and for system bandwidths of 1.25, 2.5, 5, 10, or 20 MHz, there can be 1, 2, 4, 8, or 16 sub-bands, respectively.

[0096] LTE supports a single set of parameters (subcarrier gap (SCS), symbol length, etc.). In contrast, NR can support multiple sets of parameters (μ), such as subcarrier gaps of 15 kHz (μ=0), 30 kHz (μ=1), 60 kHz (μ=2), 120 kHz (μ=3), and 240 kHz (μ=4) or larger. Within each subcarrier gap, each time slot has 14 symbols. For a 15 kHz SCS (μ=0), there is one time slot per subframe, with 10 time slots per frame. The duration of each time slot is 1 millisecond (ms), the symbol duration is 66.7 microseconds (μs), and the maximum nominal system bandwidth (in MHz) of 4K FFT size is 50. For a 30 kHz SCS (μ=1), each subframe has two time slots, with 20 time slots per frame. The duration of each time slot is 0.5 ms, the symbol duration is 33.3 μs, and the maximum nominal system bandwidth (in MHz) for a 4K FFT is 100. For a 60 kHz SCS (μ=2), each subframe has four time slots, with 40 time slots per frame. The duration of each time slot is 0.25 ms, the symbol duration is 16.7 μs, and the maximum nominal system bandwidth (in MHz) for a 4K FFT is 200. For a 120 kHz SCS (μ=3), each subframe has eight time slots, with 80 time slots per frame. The duration of each time slot is 0.125 ms, the symbol duration is 8.33 μs, and the maximum nominal system bandwidth (in MHz) for a 4K FFT is 400. For a 240 kHz SCS (μ=4), there are 16 time slots per subframe, 160 time slots per frame, a time slot duration of 0.0625 ms, a symbol duration of 4.17 μs, and a maximum nominal system bandwidth (in MHz) of 4K FFT size.

[0097] In the examples of Figures 4A to 4D, a parameter set of 15 kHz was used. Therefore, in the time domain, a 10-millisecond frame is divided into 10 sub-frames of the same size, each sub-frame being 1 millisecond, and each sub-frame including a time slot. In Figures 4A to 4D, time is represented in a horizontal direction (e.g., on the X-axis) where time increases from left to right, while frequency is represented in a vertical direction (e.g., on the Y-axis) where frequency increases (or decreases) from bottom to top.

[0098] A resource grid can be used to represent time slots, each of which includes one or more concurrent resource blocks (RBs) (also known as physical RBs (PRBs)) in the frequency domain. The resource grid is further divided into multiple resource elements (REs). An RE can correspond to a symbol length in the time domain and a subcarrier in the frequency domain. In the parameter sets of Figures 4A to 4D, for a normal cyclic prefix, an RB can contain 12 consecutive subcarriers in the frequency domain and seven consecutive symbols in the time domain, for a total of 84 REs. For an extended cyclic prefix, an RB can contain 12 consecutive subcarriers in the frequency domain and six consecutive symbols in the time domain, for a total of 72 REs. The number of bits carried by each RE depends on the modulation scheme.

[0099] Some REs carry downlink reference (boot frequency) signals (DL-RS). DL-RS may include positioning reference signals (PRS), tracking reference signals (TRS), phase tracking reference signals (TRS), cell-specific reference signals (CRS), channel state information reference signals (CSI-RS), demodulation reference signals (DMRS), primary synchronization signals (PSS), secondary synchronization signals (SSS), synchronization signal blocks (SSB), etc. Figure 4A illustrates an example location of a RE (labeled "R") carrying a PRS.

[0100] The set of resource elements (REs) used for transmitting PRS is called a "PRS resource". The set of resource elements can span multiple PRBs in the frequency domain and 'N' (such as one or more) consecutive symbols within a time slot in the time domain. In a given OFDM symbol in the time domain, a PRS resource occupies a consecutive PRB in the frequency domain.

[0101] The transmission of PRS resources within a given PRB has a specific comb size (also known as "comb density"). The comb size 'N' represents the subcarrier gap (or frequency / tone gap) within each symbol of the PRS resource configuration. Specifically, for a comb size 'N', the PRS is transmitted in every Nth subcarrier of a symbol in the PRB. For example, for comb-4, for each symbol of the PRS resource configuration, the RE corresponding to every fourth subcarrier (such as subcarriers 0, 4, 8) is used to transmit the PRS of the PRS resource. Currently, comb sizes of comb-2, comb-4, comb-6, and comb-12 are supported for DL-PRS. Figure 4A illustrates an example PRS resource configuration for comb-6 (which spans six symbols). That is, the position of the shaded RE (labeled "R") indicates the comb-6 PRS resource configuration.

[0102] Currently, DL-PRS resources can span 2, 4, 6, or 12 consecutive symbols within a single time slot, employing a full-frequency-domain interleaved mode. DL-PRS resources can be configured in downlink or elastic (FL) symbols of any higher-layer configuration time slot. For all REs of a given DL-PRS resource, there may be a constant energy per resource element (EPRE). The following are the frequency offsets with comb sizes of 2, 4, 6, and 12 over 2, 4, 6, and 12 symbols. 2-symbol comb-2: {0, 1}; 4-symbol comb-2: {0, 1, 0, 1}; 6-symbol comb-2: {0, 1, 0, 1, 0, 1}; 12-symbol comb-2: {0, 1, 0, 1, 0, 1, 0, 1, 0, 1}; 4-symbol comb-4: {0, 2, 1, 3}; 12-symbol comb-4: {0, 2, 1, 3, 0, 2, 1, 3, 0, 2, 1, 3}; 6-symbol comb-6: {0, 3, 1, 4, 2, 5}; 12-symbol comb-6: {0, 3, 1, 4, 2, 5, 0, 3, 1, 4, 2, 5}; 12-symbol comb-12: {0, 6, 3, 9, 1, 7, 4, 10, 2, 8, 5, 11}.

[0103] A "PRS resource set" is a group of PRS resources used to transmit 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 a PRS resource set ID and associated with a specific TRP (e.g., identified by a TRP ID). Additionally, PRS resources in a PRS resource set have the same periodicity, a common silence mode configuration, and the same repetition factor (such as "PRS-resource repetition factor") across time slots. Periodicity refers to the time from the first repetition of the first PRS resource in the first PRS instance to the same first repetition of the same first PRS resource in the next PRS instance. The period can have the length of a time slot selected from 2^μ*{4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 160, 320, 640, 1280, 2560, 5120, 10240}, where μ = 0, 1, 2, 3. The repeat factor can have the length of the slot selected from {1, 2, 4, 6, 8, 16, 32}.

[0104] The PRS resource ID in a PRS resource set is associated with a single beam (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 a "resource" can also be referred to as a "beam". It should be noted that this has no effect on whether the UE knows the TRP and the beam transmitting the PRS.

[0105] A “PRS instance” or “PRS timing” is an instance of a periodic recurring time window (such as a group of one or more consecutive time slots) in which a PRS is expected to be sent. 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”.

[0106] A “Frequency Layer” (also simply referred to as a “Frequency Layer”) is a collection of one or more PRS resource sets spanning one or more TRPs (with some parameters having the same values). Specifically, the collection of PRS resource sets has the same subcarrier gap and cyclic prefix (CP) type (meaning that all parameter sets supported for PDSCH are also supported for PRS), the same point A, the same downlink PRS bandwidth value, the same starting PRB (and center frequency), and the same comb size. The point A parameter is the parameter “ARFCN-value NR” ​​(where “ARFCN” stands for “Absolute Radio Channel Number”) and is an identifier / code that specifies a pair of physical radio channels used for transmission and reception. The downlink PRS bandwidth can have a minimum of four PRBs and a maximum of 24 PRBs and a maximum of 272 PRBs. Currently, a maximum of four frequency layers have been defined, and each TRP of each frequency layer can be configured with a maximum of two PRS resource sets.

[0107] The concept of a frequency layer is somewhat similar to that of component carriers and bandwidth portions (BWP), but the difference is that component carriers and BWPs are used by a single base station (or macrocell and microcell base stations) to transmit data channels, while a frequency layer is used by several (usually three or more) base stations to transmit PRS. When a UE transmits its positioning capabilities to the network (such as during LTE Positioning Protocol (LPP) communications), it can indicate the number of frequency layers it can support. For example, a UE can indicate whether it can support one or four positioning frequency layers.

[0108] Figure 4B illustrates examples of various channels within a downlink time slot in a radio communication frame. In NR, channel bandwidth or system bandwidth is divided into multiple BWPs. A BWP is a set of consecutive PRBs, which is a consecutive subset of common RBs selected from a specific set of parameters on a specific carrier. Generally, a maximum of four BWPs can be specified in the downlink and uplink. That is, a UE can be configured with a maximum of four BWPs in the downlink and a maximum of four BWPs in the uplink. At any given time, only one BWP (uplink or downlink) can be active, which means that the UE can only receive or transmit via one BWP at a time. In the downlink, the bandwidth of each BWP should be equal to or greater than the bandwidth of the SSB, but it may or may not contain the SSB.

[0109] Referring to Figure 4B, the Primary Synchronization Signal (PSS) is used by the UE to determine the subframe / symbol timing and physical layer. The UE uses the Secondary Synchronization Signal (SSS) to determine the physical layer cell identifier group number and radio frame timing. Based on the physical layer identifier and the physical layer cell identifier group number, the UE can determine the PCI. Based on the PCI, the UE can determine the location of the aforementioned DL-RS. The Physical Broadcast Channel (PBCH) carrying the MIB can logically be grouped with the PSS and SSS to form the SSB (also known as SS / PBCH). The MIB provides the number of RBs and the System Frame Number (SFN) in the downlink system bandwidth. The Physical Downlink Shared Channel (PDSCH) carries user data and broadcast system information not transmitted by the PBCH, such as System Blocks (SIBs) and paging messages.

[0110] The physical downlink control channel (PDCCH) carries downlink control information (DCI) within one or more control channel elements (CCEs). Each CCE includes one or more RE group (REG) bundles (which can span multiple symbols in the time domain). Each REG bundle includes one or more REGs, and each REG corresponds to 12 resource elements (one resource block) in the frequency domain and one OFDM symbol in the time domain. The physical resource set used to carry PDCCH / DCI is called a control resource set (CORESET) in NR. In NR, a PDCCH is confined to a single CORESET and transmitted along with its own DMRS. This enables UE-specific beamforming for the PDCCH.

[0111] In the example of Figure 4B, each BWP has a CORESET, and the CORESET spans three symbols in the time domain (although it may only have one or two symbols). Unlike the LTE control channel, which occupies the entire system bandwidth, in NR, the PDCCH channel is located in a specific region (i.e., the CORESET) in the frequency domain. Therefore, the frequency components of the PDCCH shown in Figure 4B are shown in the frequency domain as smaller than a single BWP. It should be noted that although the CORESET shown is continuous in the frequency domain, it does not have to be continuous. Furthermore, the span of the CORESET in the time domain can be less than three symbols.

[0112] The DCI within the PDCCH carries information about uplink resource configuration (persistent and non-persistent) and a description of downlink data sent to the UE, referred to as uplink and downlink grants, respectively. More specifically, the DCI indicates resources scheduled for downlink data channels (e.g., PDSCH) and uplink data channels (e.g., PUSCH). Multiple (e.g., up to eight) DCIs can be configured in the PDCCH, and these DCIs can have one of several formats. For example, there are different DCI formats for uplink scheduling, for downlink scheduling, for uplink transmit power control (TPC), etc. A PDCCH can be transmitted by 1, 2, 4, 8, or 16 CCEs to accommodate different DCI payload sizes or coding rates.

[0113] As shown in Figure 4C, some REs (labeled "R") carry DMRS for channel estimation at the receiver (e.g., base station, another UE, etc.). The UE may additionally transmit SRS in, for example, the last symbol of a time slot. The SRS may have a comb structure, and the UE may transmit SRS on one of the combs. In the example of Figure 4C, the SRS shown is comb-2 on one symbol. The SRS can be used by the base station to obtain Channel State Information (CSI) for each UE. The CSI describes how the RF signal propagates from the UE to the base station and represents the combined effects of scattering, attenuation, and power attenuation with distance. The system uses the SRS for resource scheduling, link adaptation, massive MIMO, beam management, etc.

[0114] Currently, SRS resources can span 1, 2, 4, 8, or 12 consecutive symbols within time slots with comb sizes of comb-2, comb-4, or comb-8. The following are the symbol-to-symbol frequency offsets for currently supported SRS comb modes. 1-symbol comb-2: {0}; 2-symbol comb-2: {0, 1}; 4-symbol comb-2: {0, 1, 0, 1}; 4-symbol comb-4: {0, 2, 1, 3}; 8-symbol comb-4: {0, 2, 1, 3, 0, 2, 1, 3}; 12-symbol comb-4: {0, 2, 1, 3, 0, 2, 1, 3, 0, 2, 1, 3}; 4-symbol comb-8: {0, 4, 2, 6}; 8-symbol comb-8: {0, 4, 2, 6, 1, 5, 3, 7}; and 12-symbol comb-8: {0, 4, 2, 6, 1, 5, 3, 7, 0, 4, 2, 6}.

[0115] The set of resource elements used for SRS transmission is called an "SRS resource" and can be identified by the parameter "SRS-ResourceId". The set of resource elements can span multiple PRBs in the frequency domain and N (e.g., one or more) consecutive symbols in a time slot in the time domain. In a given OFDM symbol, SRS resources occupy consecutive PRBs. An "SRS resource set" is the set of SRS resources used for SRS signal transmission and is identified by the SRS resource set ID ("SRS-ResourceSetId").

[0116] Generally, a UE transmits an SRS to enable a receiving base station (serving base station or adjacent base station) to measure the channel quality between the UE and the base station. However, an SRS can also be specifically configured as an uplink positioning reference signal for uplink-based positioning procedures, such as uplink time difference of arrival (UL-TDOA), round-trip time (RTT), and uplink angle of arrival (UL-AOA). As used herein, the term "SRS" may refer to an SRS configured for channel quality measurement or an SRS configured for positioning purposes. The former may be referred to herein as "communication SRS" and / or the latter as "positioning SRS," as needed to distinguish between the two types of SRS.

[0117] For positioning SRS (also known as "UL-PRS"), several enhancements to the previous SRS definition have been proposed, such as new interleaving patterns within SRS resources (except for single symbol / comb-2), new comb types for SRS, new sequences of SRS, a larger set of SRS resources per component carrier, and a larger number of SRS resources per component carrier. Furthermore, the parameters "SpatialRelationInfo" and "PathLossReference" are configured based on downlink reference signals or SSBs from adjacent TRPs. Further, an SRS resource can be transmitted outside the active BWP, and an SRS resource can span multiple component carriers. Additionally, SRS can be configured in RRC connected state and transmitted only within the active BWP. Furthermore, there may be no frequency hopping, no repetition factor, only a single antenna port, and new SRS lengths (e.g., 8 and 12 symbols). Open-loop power control may also be possible instead of closed-loop power control, and comb-8 may be used (i.e., one SRS is transmitted every eighth subcarrier in the same symbol). Finally, the UE can transmit UL-AoA via the same transmit beam of multiple SRS resources. All of these are additional features of the current SRS frame, which are configured via RRC higher-layer signaling (and may be triggered or activated via MAC control element (CE) or DCI).

[0118] Figure 4D illustrates examples of various channels within the uplink time slots of a frame according to the present invention. The Random Access Channel (RACH), also known as the Physical Random Access Channel (PRACH), is configured based on the PRACH and can reside in one or more time slots within a frame. A PRACH can include six consecutive RB pairs within a time slot. The PRACH allows the UE to perform initial system access and implement uplink synchronization. The Physical Uplink Control Channel (PUCCH) can be located at the edge of the uplink system bandwidth. The PUCCH carries uplink control information (UCI), such as scheduling requests, CSI reports, Channel Quality Indicator (CQI), Precoding Matrix Indicator (PMI), Rank Indicator (RI), and HARQ ACK / NACK feedback. The Physical Uplink Shared Channel (PUSCH) carries data and can also be used to carry Buffer Status Report (BSR), Power Headroom Report (PHR), and / or UCI.

[0119] It should be noted that the terms "location reference signal" and "PRS" generally refer to specific reference signals used for positioning in NR and LTE systems. However, as used herein, the terms "location reference signal" and "PRS" can also refer to any type of reference signal that can be used for positioning, such as, but not limited to, PRS, TRS, PTRS, CRS, CSI-RS, DMRS, PSS, SSS, SSB, SRS, UL-PRS, etc., as defined in LTE and NR. Furthermore, the terms "location reference signal" and "PRS" can refer to downlink or uplink positioning reference signals, unless the context otherwise requires. If further distinction is needed regarding the type of PRS, downlink positioning reference signals can be referred to as "DL-PRS," while uplink positioning reference signals (e.g., positioning SRS, PTRS) can be referred to as "UL-PRS." Additionally, for signals that can be transmitted in both the uplink and downlink (e.g., DMRS, PTRS), "UL" or "DL" can be added before the signal to distinguish the direction. For example, "UL-DMRS" can be distinguished from "DL-DMRS."

[0120] Figure 5 is a diagram of an example PRS resource set with different time slots according to the state of this case. In the example of Figure 5, time is represented horizontally and frequency is represented vertically. Each block represents a time slot in the time domain and some bandwidth in the frequency domain.

[0121] Figure 5 illustrates two DL-PRS resource set configurations: a first DL-PRS resource set configuration 510 and a second DL-PRS resource set configuration 550. Each of DL-PRS resource set configurations 510 and 550 includes four PRS resources (labeled "Resource 1", "Resource 2", "Resource 3", and "Resource 4") and has a repetition factor of four. A repetition factor of four means that each of the four PRS resources is repeated four times within the DL-PRS resource set (i.e., sent four times). In other words, each of the four PRS resources within the DL-PRS resource set has four repetitions.

[0122] The DL-PRS resource set configuration 510 has a time slot interval of one time slot, meaning that each repetition of a PRS resource (e.g., "Resource 1") begins in the first time slot after the previous repetition of that PRS resource. Therefore, as shown in the DL-PRS resource set configuration 510, the four repetitions of each of the four PRS resources are grouped together. In particular, the four repetitions of PRS resource "Resource 1" occupy the first four time slots of the DL-PRS resource set configuration 510 (i.e., time slots n to n+3), the four repetitions of PRS resource "Resource 2" occupy the second group of four time slots (i.e., time slots n+4 to n+7), the four repetitions of PRS resource "Resource 3" occupy the third group of four time slots (i.e., time slots n+8 to n+11), and the four repetitions of PRS resource "Resource 4" occupy the last four time slots (i.e., time slots n+12 to n+15).

[0123] Conversely, the DL-PRS resource set configuration 550 has a time slot of four time slots, meaning that each repetition of a PRS resource (e.g., "Resource 2") begins in the fourth time slot after the previous repetition of that PRS resource. Therefore, as shown in the DL-PRS resource set configuration 550, four repetitions of each of the four PRS resources are scheduled every four time slots. For example, the four repetitions of the PRS resource "Resource 1" occupy the first, fifth, ninth, and thirteenth time slots of the DL-PRS resource set configuration 550 (i.e., time slots n, n+4, n+8, and n+12).

[0124] Note that, as shown in Figure 5, the duration spanned by a DL-PRS resource set containing repeating DL-PRS resources should not exceed the PRS period. Furthermore, the UE receive beam scan used for receiving / measuring the DL-PRS resource set is not specified and depends on the UE implementation.

[0125] NR supports many cellular-based positioning technologies, including downlink-based, uplink-based, and downlink-and-uplink-based positioning methods. Downlink-based positioning methods can include Observed Time Difference of Arrival (OTDOA) in LTE, Downlink Time Difference of Arrival (DL-TDOA) in NR, and Downlink Angle of Departure (DL-AoD) in NR. In an OTDOA or DL-TDOA positioning procedure, the UE measures the difference in the time of arrival (ToA) of a reference signal (e.g., a positioning reference signal (PRS)) received from a pair of base stations, referred to as the Reference Signal Time Difference (RSTD) or Time Difference of Arrival (TDOA) measurement, and reports it to the positioning entity. More specifically, the UE receives identifiers (IDs) of a reference base station (e.g., a serving base station) and multiple non-reference base stations in auxiliary data. The UE then measures the RSTD between the reference base station and each non-reference base station. Based on the known locations of the participating base stations and the RSTD measurement, the positioning entity can estimate the UE's location.

[0126] For DL-AoD positioning, the positioning entity uses beam reports of received signal strength measurements from multiple downlink transmitted beams from the UE to determine multiple angles between the UE and the transmitting base station. Subsequently, the positioning entity can estimate the UE's location based on the determined multiple angles and the multiple known locations of the transmitting base station.

[0127] Uplink-based positioning methods include uplink time difference of arrival (UL-TDOA) and uplink angle of arrival (UL-AoA). UL-TDOA is similar to DL-TDOA, but is based on uplink reference signals (e.g., sounding reference signals (SRS)) transmitted by the UE. For UL-AoA positioning, one or more base stations measure the received signal strength of one or more uplink reference signals (e.g., SRS) received from the UE on one or more uplink receive beams. The positioning entity uses the signal strength measurement and the angles of(multiple) receive beams(multiple) to determine(multiple) angles between the UE and(multiple) base stations(multiple). Based on the determined angles(multiple) and the known locations of(multiple) base stations(multiple), the positioning entity can then estimate the location of the UE.

[0128] Downlink and uplink-based localization methods include Enhanced Cell ID (E-CID) localization and Multiple Round Trip Time (RTT) localization (also known as "Multi-Cell RTT"). In an RTT procedure, the initiator (base station or UE) sends an RTT measurement signal (e.g., PRS or SRS) to the responder (UE or base station), and the responder sends an RTT response signal (e.g., SRS or PRS) back to the initiator. The RTT response signal includes the difference between the ToA of the RTT measurement signal and the transmission time of the RTT response signal, referred to as the receive-transmit (RxTx) time difference. The initiator calculates the difference between the transmission time of the RTT measurement signal and the ToA of the RTT response signal, referred to as the transmit-receive (Tx-Rx) time difference. The propagation time (also known as "time of flight") between the initiator and the responder can be calculated from the Tx-Rx and RxTx time differences. Based on the propagation time and the known speed of light, the distance between the initiator and the responder can be determined. For multi-RTT positioning, the UE performs RTT procedures with multiple base stations to determine its location based on the known locations of the base stations (e.g., using multilateral positioning). RTT and multi-RTT methods can be combined with other positioning technologies (such as UL-AoA and DL-AoD) to improve location accuracy.

[0129] The E-CID positioning method is based on Radio Resource Management (RRM) measurements. In E-CID, the UE reports the serving cell ID, timing advance (TA), and the identifiers, estimated timings, and signal strengths of detected neighboring base stations. The UE's location is then estimated based on this information and the known locations of the base stations.

[0130] To assist in the positioning operation, a location server (e.g., location server 230, LMF 270, SLP 272) may provide auxiliary data to the UE. For example, the auxiliary data may include the identifier of the base station (or cell / TRP of the base station) from which it measures the reference signal, reference signal configuration parameters (e.g., the number of consecutive positioning sub-frames, the period of the positioning sub-frames, the silence sequence, the frequency hopping sequence, the reference signal identifier, the reference signal bandwidth, etc.), and / or other parameters applicable to a particular positioning method. Alternatively, the auxiliary data may come directly from the base station itself (e.g., in periodically broadcast management burden messages, etc.). In some cases, the UE can detect neighboring network nodes itself without using auxiliary data.

[0131] In the case of OTDOA or DL-TDOA positioning procedures, auxiliary data may further include the expected RSTD value and the associated uncertainty or search window around the expected RSTD. In some cases, the expected RSTD value may range from + / - 500 microseconds (μs). In some cases, when any resource used for positioning measurements is in FR1, the uncertainty of the expected RSTD may range from + / - 32 μs. In other cases, when all resources used for positioning measurements (multiple) are in FR2, the uncertainty of the expected RSTD may range from + / - 8 μs.

[0132] Location estimation may be represented by other names, such as location estimate, location, location fixed, fixed, or similar. Location estimation may be geodetic and include coordinates (e.g., latitude, longitude, and possible elevation) or may be urban and include street addresses, postal addresses, or some other verbal description of the location. Location estimation may also be defined relative to some other known location or in absolute terms (e.g., using latitude, longitude, and possible elevation). Location estimation may include expected errors or uncertainties (e.g., by including an area or volume within which the location is expected to be included at a specified or preset confidence level).

[0133] Figure 6 illustrates an exemplary wireless communication system 600, illustrating an implementation of positioning using downlink time difference of arrival (TDOA) technology. In the example of Figure 6, UE 104 determines an estimate of its location or assists another entity (e.g., a base station or core network component, another UE, a location server, a collaborating application, etc.) in determining an estimate of its location. UE 104 can wirelessly communicate with a plurality of base stations 102-1, 102-2, and 102-3 (collectively referred to as base stations 102) using RF signals and standardized protocols for modulating RF signals and exchanging information packets, which can correspond to any combination of base stations 102, 180 in Figure 1A. By extracting different types of information from the exchanged RF signals and utilizing the layout of the wireless communication system 600 (i.e., the location, geometry, etc. of the base stations), UE 104 can determine its location or assist in determining its location in a predefined reference coordinate system. In one configuration, UE 104 can use a two-dimensional coordinate system to specify its location; however, the configurations disclosed herein are not limited to this, and a three-dimensional coordinate system can also be used to determine the location if additional dimensions are required. Furthermore, although Figure 6 illustrates one UE 104 and three base stations 102, it is understood that there can be more UEs 104 and more or fewer base stations 102.

[0134] To support location estimation, base station 102 may be configured to broadcast reference RF signals (e.g., PRS, CRS, CSI-RS, synchronization signals, etc.) to UE 104 within its coverage area, enabling UE 104 to measure the characteristics of such reference RF signals. For example, Figure 6 illustrates base station 102-1 sending downlink reference signal (PRS) 602 to UE 104, and base stations 102-2 and 102-3 sending downlink reference signals (PRS) 604 and 606 to the UE, respectively. UE 104 may use a DL-TDOA (e.g., OTDOA) positioning method, which is a multi-point positioning method in which the UE typically measures the time of arrival (TOA) of reference RF signals (e.g., PRS, CRS, CSI-RS, etc.) transmitted by different network node pairs (e.g., base station 102, base station 102's antennas, etc.). Transmit and / or receive beamforming at base station and / or UE 104 can enable wideband bandwidth to improve accuracy. The RSTD of a base station pair can be determined by subtracting the TOA from the TOA from the reference base station from the TOA of several adjacent base stations.

[0135] Typically, RSTD is measured between a reference network node and one or more adjacent network nodes. In the example shown in Figure 6, base station 102-1 can be the serving base station of UE 104 and can also be used as a reference base station, while base stations 102-2 and 102-3 are used as adjacent base stations. The reference network node remains the same for all RSTDs measured by UE 104, used for any single location of OTDOA, and typically corresponds to the serving cell of UE 104 or another nearby cell with good signal strength at UE 104. In one case, where the measured network node is a cell supported by a base station, the adjacent network node is typically a cell supported by a base station different from the base station of the reference cell and may have good or poor signal strength at UE 104. RSTD is typically the relative timing difference between two cells (e.g., the reference cell and the adjacent cell), which is determined based on the minimum time difference between the boundaries of two subframes from the two different cells.

[0136] Location calculation can be based on the measured time difference (e.g., RSTD) and knowledge of the location of network nodes and relative transmission timing (e.g., whether network nodes are accurately synchronized, or whether each network node transmits with a known time difference relative to other network nodes).

[0137] To assist in the positioning operation, the location server 172 shown in Figure 1A (e.g., LMF 270 shown in Figure 2B) can provide UE 104 with OTDOA auxiliary information for a reference network node (e.g., base station 102-1 in the example of Figure 6) and neighboring network nodes relative to the reference network node (e.g., base stations 101-2 and 102-3 in the example of Figure 6). For example, the auxiliary information can provide the center channel frequency of each network node, various reference RF signal configuration parameters (e.g., the number of consecutive positioning sub-frames, positioning sub-frame periodicity, silence sequence, frequency hopping sequence, reference RF signal ID, reference RF signal bandwidth), network node global ID, and / or other cell-related parameters applicable to OTDOA, as described above. The OTDOA auxiliary information can also indicate the serving cell of UE 104 as the reference network node.

[0138] In one scenario, although the location server 172 (e.g., LMF 270) can send auxiliary data to the UE 104, alternatively, the auxiliary data can originate directly from the network node (e.g., base station 102) itself (e.g., in periodically broadcast management burden messages, etc.). Alternatively, the UE 104 can detect neighboring network nodes on its own without using auxiliary data.

[0139] In the example of Figure 6, the measurement time difference between the reference cell of base station 102-1 and the adjacent cells of base stations 102-2 and 102-3 is represented as τ2–τ1 and τ3–τ1, respectively, where τ1, τ2, and τ3 represent the time when the UE 104 receives the reference RF signal from the transmit antenna(s) of base stations 102-1, 102-2, and 102-3, and include any measurement noise at the UE 104. The UE 104 can then convert the ToA measurements for different network nodes into RSTD measurements (e.g., as defined in 3GPP TS 36.214 entitled "Physical layer; Measurements") and (optionally) send them to the location server 172. The location of UE 104 can be determined by using (i) RSTD measurements, (ii) known absolute or relative transmission timing of each network node, (iii) known locations of the physical transmit antennas of reference and adjacent network nodes, and / or (iv) directional reference RF signal characteristics, such as transmission direction.

[0140] The shortest path ToA Ti from base station i to UE 104 is given by , where Di is the Euclidean distance between base station i with position (qi) and UE 104 with position (p), c is the speed of light in the air (299700 km / s), and qi is known via the cellular information database. The Euclidean distance (i.e., the straight-line distance between two points) is provided by the following equation: , Equation 1

[0141] Where D is the distance between two points on the Earth’s surface, R is the radius of the Earth (6371 km), and the latitudes of the first point (in radians) and the second point (in radians) are respectively, and the longitudes of the first point (in radians) and the second point (in radians) are respectively.

[0142] To identify the ToA of a reference RF signal transmitted by a given network node, UE 104 first jointly processes all resource elements (REs) on the channel on which the network node (e.g., base station 102) transmits the reference RF signal, and performs an inverse Fourier transform to convert the received RF signal to the time domain. This time-domain conversion of the received RF signal is called the estimation of the Channel Energy Response (CER). The CER shows the peak values ​​on the channel over time, so the earliest "significant" peak should correspond to the ToA of the reference RF signal. Typically, the UE will use a noise-related quality threshold to filter out spurious local peaks, thus correctly identifying significant peaks on the channel. For example, UE 104 may select a ToA estimate that is at least X dB higher than the median of the CER and at most Y dB lower than the dominant peak on the channel as the earliest local maximum value of the CER. UE 104 determines the CER of each reference RF signal from each network node in order to determine the ToA of each reference RF signal from different network nodes.

[0143] The TOA measurement performed by UE 104 is related to the geometric distance between the UE and base station 102. In a 2-D Cartesian coordinate system, the (known) coordinates of the base station can be represented as xi=[xi,yi]T, and the (unknown) coordinates of UE 104 can be represented as xt=[xt,yt]T. The RSTD measurement can be defined as the time difference (modulo 1-subframe (1-ms)) between the two base stations, and thus corresponds to the distance difference between the adjacent base station 102-i and the reference base station 102-1. Equation 2

[0144] In Equation 2, RSTDi,1 is the time difference between the adjacent base station 102-i and the reference base station 102-1 measured at UE 104, (Ti-T1) is the transmission time offset between the base stations, which is called "actual time difference" (RTD); ni and n1 are the UE TOA measurement error, and c is the speed of light.

[0145] At least two adjacent base station measurements i are required, but preferably more than two adjacent base station measurements, and the system of equations can be solved in the least squares or weighted least squares sense. The transmission time offset (Ti-T1) should ideally be zero in a synchronous network, and the equations above define the time difference of arrival (TDOA). Geometrically, each TDOA defines a hyperbola, the width of which is determined by the TDOA error (ni-n1), as shown in Figure 6. If the coordinates of base station 102 and the transmission time offset (Ti-T1) are known at location server 172 (e.g., LMF 270) or at UE 104, the location of UE 104 can be determined. Uncertainty in the coordinates of base station 102 or the transmission time offset will directly affect the accuracy of the UE location estimation. An additional source of delay or error is the hardware group delay between the UE and gNB, which is mainly due to the internal hardware delay between the baseband (BB) components and the antenna (ANT) at the UE and gNB. Hardware group delays can lead to timing and / or calibration errors, which can affect positioning measurements and thus positioning performance.

[0146] Therefore, for traditional OTDOA measurements, highly accurate and reliable network synchronization is crucial for precision. At the speed of light, one nanosecond of timing error translates to approximately one foot (about 0.3 meters) of positional error. As inter-base station synchronization degrades, OTDOA measurements become less accurate, as shown by the hyperbola in Figure 6, and the positional error increases proportionally. However, the synchronization requirements for OTDOA are far more stringent than those for communication purposes.

[0147] Uplink Time Difference of Arrival (UTDOA) is a positioning method similar to OTDOA, but it is based on an uplink reference RF signal, such as the UL PRS or SRS transmitted by the UE (e.g., UE 104). Furthermore, transmit and / or receive beamforming at network nodes and / or UE 104 can enable wideband bandwidth at the cell edge to improve accuracy. Beamforming can also utilize channel inter-procedures in 5G NR. Like OTDOA, the lack of synchronization during UTDOA positioning leads to a decrease in accuracy.

[0148] Figure 7 illustrates an exemplary wireless communication system 700, which illustrates an implementation of positioning using uplink time difference of arrival (TDOA) technology. Figure 7 is similar to Figure 6 discussed above, but illustrates UTDOA, which is the opposite of OTDOA. As shown, UE 104 transmits SRS 702 to reference base station 102-1, and simultaneously transmits SRS 704 and 706 to neighboring base stations 102-2 and 102-3, respectively. In some implementations, SRS 702, SRS 704, and SRS 706 may be the same transmission. In other implementations, SRS 702, SRS 704, and SRS 706 may be separate transmissions, wherein UE 104 measures and stores the time between the transmissions of SRS 702 and SRS 704, and between the transmissions of SRS 702 and SRS 706.

[0149] Assuming base station 102 is synchronized, the RSTD between SRS 702 and 704 can then be determined based on the difference between the reception times of SRS 702 and SRS 704 at base stations 102-1 and 102-2, minus any delay (if any) between the transmission times of SRS 702 and 704 at UE 104. Similarly, the RSTD between SRS 702 and 706 can then be determined based on the difference between the reception times of SRS 702 and SRS 706 at base stations 102-1 and 102-3, minus any delay (if any) between the transmission times of SRS 702 and 706 at UE 104. The location of UE 104 can therefore be determined based on the intersection of the resulting hyperbolas, similar to the discussion above.

[0150] Although positioning technologies (such as DL TDOA and UL TDOA shown in Figures 6 and 7) typically involve measurement procedures between the target UE and multiple base stations, in some designs, a reference device associated with a known location can participate in one or more positioning procedures. For example, sidechain positioning (e.g., using another UE or other device with a known location) can be used in place of one or more base stations in a measurement procedure, which can communicate with the target UE 104 via sidechain communication. Using sidechains for positioning may be ideal because it allows for more flexible deployment of anchor devices in the form of UEs, such as in environments where satellite-based positioning (such as Global Navigation Satellite System (GNSS)) or network positioning is compromised. For example, in indoor environments such as shopping malls, manufacturing plants, or in urban canyons, the reception of GNSS or network signals used for positioning may be poor, or there may be multipath components, interference, etc., making positioning difficult. Furthermore, sidechain positioning can operate independently of network coverage and therefore can have lower latency because it does not require establishing a network connection before positioning. Sidechain positioning also allows for relative positioning, which does not require absolute position calculations. For example, relative positioning using sidechains can be useful in public safety operations (e.g., tracking emergency personnel), vehicle applications (e.g., platooning, collision avoidance), unmanned aerial vehicle (UAV) applications (e.g., approaching docking stations or landing), augmented reality (AR) applications (e.g., user interaction within AR), smart home entertainment applications (e.g., connectivity and interaction between devices), and more.

[0151] A reference device (such as a UE with a recently located fixed location, a roadside unit (RSU), etc.) may be configured to support downlink-related location (such as DL-TDOA), uplink-related location (such as UL-TDOA), or a combination of downlink and uplink-related location (such as RTT). The reference device may be configured to support DL-PRS (or sidechain (SL-PRS)) measurements and report associated measurements (e.g., RSTD, RxTx time difference, RSRP) to the LMF (or report UE-based location to the UE), send UL-PRS (or SL-PRS) and report associated measurements (e.g., Tx time, RxTx time difference, etc.). The reference device may sometimes be referred to herein as an anchor device for location. Furthermore, a base station may sometimes be referred to as a (fixed) anchor device for location.

[0152] Figure 8 illustrates, by way of example, the timing of the time difference measurement signal exchanged between the target UE 104 and a fixed anchor such as BS A (e.g., base station 102) and reference device B (e.g., UE 104 with a known location or another base station 102). In this example, BS A and reference device B are stationary and have known locations. The timing of Figure 8 illustrates that the difference (T_RxTx) between the reception Rx time of PRS#1 and the transmission time of PRS#2 of reference device B is denoted as τB, and the difference (T_Rx-Rx) between the reception Rx time of PRS#1 and the reception time of PRS#2 at the target UE 104 is denoted as τUE. The sum and denots used herein represent measurements.

[0153] TDOA-based positioning largely depends on network synchronization (between gNBs) to achieve positioning accuracy. By introducing a reference device (hereinafter referred to as Reference Device B) with a known fixed location (either the UE or a gNB), the requirement for gNB synchronization can be relaxed by incorporating the anchor-to-anchor time measurement (Rx-Tx time difference) into the calculation of RSTD(), thus, Equation 3, where ToF (Time of Flight) is the propagation time between the two nodes, and the propagation delay between BS A and Reference Device B can be obtained from almanac information (e.g., since the locations of BS A and Reference Device B are known, the propagation delay between BS A and Reference Device B can be calculated rather than measured).

[0154] Assuming that the memory has a constant clock drift over a short period of time, the measured value is denoted as , where e is the clock drift, which can be ±0.1 ppm for both UE and gNB. The error mainly depends on, for example: Equation 4, where is the main part of the error, and can be ±0.2 ppm.

[0155] In some systems, this level of error may be unacceptable. For example, in some designs, the average value of the basic measurement of the UE modulated carrier frequency may need to be accurate to within ±0.1 ppm over a cumulative measurement interval of 1 ms, compared to the carrier frequency received from the NR node B.

[0156] In some designs, the error caused by time drift depends primarily on the PRS#1 to PRS#2 gap (). For increased accuracy requirements in 3GPP Rel-17 (e.g., 1 m for general commercial use, or 20 cm for IIoT), assuming a 10% error margin, the maximum required PRS#1 to PRS#2 gaps for accumulated ±0.2 ppm can be 1.67 ms and 0.33 ms respectively, for example: Equation 5

[0157] Figure 9 illustrates an exemplary process 900 of the TDOA procedure, which uses time drift mitigation to improve the positioning accuracy of the location estimation of the target UE 104. In Figure 9, similar to Figure 8, measurement signals are exchanged between BS A (e.g., base station 102), reference device B (e.g., UE 104 with a known location or another base station 102), and the target UE 104. In this example, BS A and reference device B are stationary and have known locations.

[0158] For the context, the baseline DL-TDOA algorithm is, with associated error. However, this baseline DL-TDOA algorithm can compensate for time drift, for example: Equation 6, where the information can be obtained from almanac information (e.g., since the positions of BS A and reference device B are known, the propagation delay between BS A and reference device B can be calculated instead of measured). In this case, the error can be, which is lower than the error of the baseline DL-TDOA algorithm as shown in Equation 4 above. For it to be effective, the drift correction reference duration must be long to be effective; otherwise, the multiplication correction factor (e.g., ) will be a constant 1.

[0159] In an example, a pairwise RSTD can be measured by the target UE 104, which is associated with a pairwise PRS (PRS#1 and #3) from BS A and another PRS (PRS#2) from reference device B, for example, to obtain and . For UE-assisted positioning, the measured RSTD is reported to the LMF. An alternative option is to report the associated ratio. In some designs, a pairwise RxTx time difference is measured by reference device B, which is associated with a pairwise PRS (PRS#1 and #3) from BS A, for example, to obtain and . For UE-assisted positioning, the pairwise RxTx time difference is reported to the LMF. For UE-based positioning, the pairwise RxTx time difference is reported to the UE. An alternative option is to report the associated ratio.

[0160] The use of reference devices, such as reference device B in Figures 8 and 9, is based on the premise that the reference device is fixed. However, a fixed reference device may not be suitable for all environments. For example, in some environments, there may be a reference device with a known location that can be used for positioning, but the reference device can be mobile. By way of example, a mobile reference device with a known location could be a vehicle UE.

[0161] For example, in a vehicle-to-everything (V2X) wireless system, a mobile vehicle UE can be used over time as multiple reference devices (anchors) to locate a relatively fixed target UE, such as a UE held by a pedestrian.

[0162] For example, Figure 10 illustrates a wireless communication system 1000 for locating a target UE 104 in vehicle-to-everything (V2X) communication using downlink time difference of arrival (TDOA) technology with a fixed (stationary) anchor 1002 and a mobile anchor 1006. It should be understood that Figure 10 illustrates a single mobile anchor 1006 at multiple times (t1, t2, t3, and t4), illustrating the change in the position of the mobile anchor 1006 relative to the target UE 104 over time. For example, the mobile anchor 1006 at times t2, t3, and t4 is shown with dashed lines and a lighter color than it is shown at time t1.

[0163] In some implementations, the wireless communication system 1000 may be a cellular V2X (C-V2X) system. Generally, V2X services have two operation modes, as defined in 3GPP TS 23.285. One operation mode uses direct wireless communication between V2X entities (e.g., target UE 104, fixed anchor 1002, and mobile anchor 1006). The other operation mode uses network-based wireless communication between entities. These two operation modes may be used in combination, or other operation modes may be used if required.

[0164] As shown in Figure 10, the wireless communication system 100 can operate using direct or indirect wireless communication between the target UE 104 and the fixed anchor 1002 and the mobile anchor 1006. For example, the wireless communication can be via, for example, a proximity-based service (ProSe) direction communication (PC5) reference point defined in 3GPP TS 23.303, and can use IEEE 1609, wireless access in a vehicle environment (WAVE), intelligent transportation systems (ITS), and IEEE 802.11p on the 5.9 GHz ITS band, or other wireless connections between entities. The wireless communication system 100 can use, for example, vehicle-to-everything (V2X) communication standards, where information is transferred between vehicles and other entities within the wireless communication network. V2X services include, for example, vehicle-to-vehicle (V2V), vehicle-to-pedestrian (V2P), vehicle-to-infrastructure (V2I), and vehicle-to-network (V2N) services. The V2X standard aims to develop autonomous or semi-autonomous driving systems, such as ADAS, which assist drivers in making decisions, such as lane changes, speed changes, and overtaking speeds, and can be used to assist parking, as discussed in this article. V2X uses low-latency communication and is therefore suitable for precise relative positioning, such as using RTT, TDOA, etc.

[0165] In some implementations, the fixed anchor 1002 may be a roadside unit (RSU) in a V2X system. For example, the RSU supports V2X applications and can exchange messages with other entities that support V2X applications. The RSU may be a logical entity that combines V2X application logic with the functionality of a base station in the RAN, such as an eNB, ng-eNB, or eLTE (referred to as an eNB-type RSU), or a gNB, or a UE (referred to as a UE-type RSU). If the fixed anchor 1002 is an RSU, it may communicate with the base station 102 via communication channel 120 together with one or more of the UE 104 and mobile anchors 1006. In some implementations, the fixed anchor 1002 may be the base station 102 or another UE 104 that is stationary and has a known location.

[0166] As shown in the figure, the target UE 104, fixed anchor 1002, and mobile anchor 1006 can directly communicate and transmit positioning signals, such as DL PRS, UL PRS (SRS for positioning), or SL PRS that can be used for positioning. For example, the target UE 104 and fixed anchor 1002 can directly communicate and transmit positioning signals using communication link 1005, the target UE 104 and mobile anchor 1006 can directly communicate and transmit positioning signals using communication link 1007, and the fixed anchor 1002 and mobile anchor 1006 can directly communicate and transmit positioning signals using communication link 1003. The PRS broadcast by the target UE 104, fixed anchor 1002, and mobile anchor 1006 can be any signal suitable for positioning, such as those defined for DSRC or C-V2X. The PRS can be broadcast on licensed or unlicensed spectrum. For example, in some implementations, PRS may be broadcast on one or more unlicensed National Information Infrastructure (UNII) radio bands, including, for example, one or more of the UNII-1, UNII-2A, UNII-2B, or UNII-3 radio bands. When broadcasting on unlicensed spectrum, a Listen-Before-Broadcast (LBT) protocol may be used.

[0167] The mobile anchor 1006 may be a vehicle UE (or other mobile entity) with a precise location during the time period of TDOA measurement. For example, at a first time (t1) during the TDOA positioning of the target UE 104, the mobile anchor 1006 may have a precise location, for example, due to GNSS or terrestrial positioning technology. At subsequent times during the TDOA positioning of the target UE 104 (e.g., at times t2, t3, and t4), the mobile anchor 1006 may have a known location, for example, due to dead reckoning based on the initial location at time t1 and mobility information (including speed, yaw / pitch / roll, acceleration, etc.) provided by the vehicle's onboard sensors (such as accelerometers, gyroscopes, wheel speed sensors, etc.). Alternatively or additionally, GNSS or terrestrial positioning technology may be used to obtain the updated location of the mobile anchor 1006 at subsequent times.

[0168] For a moving anchor, the TDOA algorithm for compensating drift shown in Figure 9 and Equation 6 cannot be extended in a direct manner. For example, as discussed above, for it to be effective, the drift correction reference duration shown in Figure 9 must be very long; otherwise, the multiplicative correction factor (e.g., ) will be a constant 1. If the reference device B in Figure 9 is moving, then during the long time period between the transmission of PRS#1 and PRS#3 by BSA, the reference device B will leave its initial position. For example, for a vehicle traveling at a speed of 30 m / s, a drift correction reference duration of 200 ms between PRS#1 and PRS#3 will cause the reference device B to travel 6 m from its initial position.

[0169] Therefore, if the reference device B in Figure 9 is moving, for example, if the reference device B is the moving anchor 1006 shown in Figure 10, then the reference device B can be considered as two virtual anchors at different locations, such as the gap of 6 m in the example above. Due to the change in the position of the moving anchor, the time drift shown in Figure 9 can be modified to mitigate it.

[0170] By way of example, Figure 11 illustrates an exemplary process 1100 of a TDOA procedure that uses time drift mitigation of a moving anchor to improve the positioning accuracy of the location estimation of the target UE 104.

[0171] In Figure 11, measurement signals are exchanged between anchor A 1002 (which may be an RSU), another UE with a known location, base station 102, a mobile anchor B 1006 (which may be a vehicle UE or other mobile UE), and the target UE 104. In Figure 11, anchor A 1002 and the target UE 104 are relatively stationary, while mobile anchor B 1006 is moving and is therefore considered as multiple virtual anchors. For example, Figure 11 illustrates mobile anchor B 1006, which is the same as three virtual anchors (i.e., mobile anchor B 1006, mobile anchor B' 1006, and mobile anchor B'' 1006), but which is in different relative positions to the target UE 104 over time, shown as separate isochrones t1, t2, and t3. For example, isochrones t1, t2, and t3 may correspond to the times t1, t2, and t3 shown in Figure 10. Furthermore, the RSTD group generated by the signal transmission exchange of the TDOA procedure in Figure 11 is shown as three RSTD measurement instances 1110, 1120, and 1130, identified by dotted-line squares, each instance being associated with the moving anchor B 1106 at the corresponding times t1, t2, and t3. It should be understood that although three RSTD measurement instances 1110, 1120, and 1130 are illustrated in the RSTD group in Figure 11, additional RSTD measurement instances may be included within the RSTD group if necessary, such as those corresponding to time t4 (and additional times) illustrated in Figure 10. The TDOA determined based on the RSTD measurement instances 1110, 1120, and 1130 from times t1, t2, and t3 defines the hyperbolas 1010, 1020, and 1030 shown in Figure 10, which intersect at the location of the target UE 104. Therefore, using the known position of anchor A 1002 and the known position of moving anchor B 1006 at each of times t1, t2 and t3, the position of target UE 104 can be determined.

[0172] As shown in the RSTD group in Figure 11, the fixed anchor A 1002 transmits reference signals (PRS) for a plurality of RSTD measurement instances (e.g., PRS#1, PRS#3, and PRS#5 transmitted in the respective RSTD measurement instances 1110, 1120, and 1130), and the moving anchor B 1006 transmits corresponding reference signals (PRS) in the plurality of RSTD measurement instances (e.g., PRS#2, PRS#4, and PRS#6 transmitted in RSTD measurement instances 1110, 1120, and 1130).

[0173] In RSTD measurement instance 1110, anchor A 1002 transmits PRS#1 received by mobile anchor B 1006 (at time t1) and target UE 104. In response to receiving PRS#1, after a time period, mobile anchor B 1006 transmits PRS#2 received by target UE 104. In RSTD measurement instance 1120, after the drift correction reference duration T_PRS#1--#3, anchor A 1002 transmits PRS#3 received by mobile anchor B'1006 (at time t2) and target UE 104. In response to receiving PRS#3, after a time period, mobile anchor B'1006 transmits PRS#4 received by target UE 104. In RSTD measurement example 1130, after the drift correction reference duration T_PRS#1 to -#5, anchor A 1002 transmits PRS#5, which is received by target UE 104. Additionally, mobile anchor B" 1006 transmits PRS#6, which is received by target UE 104, at time t3. It should be noted that in RSTD measurement example 1130, mobile anchor B" 1006 does not need to receive PRS#6, nor does it need to monitor the time period between receiving PRS#5 from anchor UE 1002 and transmitting PRS#6 to target UE 104.

[0174] As shown in the corresponding RSTD measurement examples 1110 and 1120, the mobile anchor B 1006 at time t1 and the mobile anchor B' 1006 at time t2 measure the RxTx time difference between receiving a reference signal (PRS) from anchor A 1002 and transmitting a reference signal (PRS) to the target UE 104. Because these RSTD measurement examples 1110 and 1120 include a mobile anchor B 1006 measuring the RxTx time difference based on receiving a reference signal from another anchor A 1002, these RSTDs include an "anchor-to-anchor" procedure. For example, in RSTD measurement instance 1110, the RxTx time difference between receiving PRS#1 and transmitting PRS#2 is marked as , and is marked as when measured by mobile anchor B 1006. In RSTD measurement instance 1120, the RxTx time difference between receiving PRS#3 and transmitting PRS#4 is marked as , and is marked as when measured by mobile anchor B'1006.

[0175] The RxTx time difference measured in two RSTD measurement instances can be used to determine clock drift errors that may be caused by non-ideal synchronization between anchor A 1002 and mobile anchor B 1006. When determining clock drift errors using two RSTD measurement instances (e.g., RSTD measurement instances 1110 and 1120), additional RSTD measurement instances can be measured for the RSTD group (RSTD measurement instance 1130) without an anchor-to-anchor procedure, i.e., without measuring the RxTx time difference between receiving the reference signal (PRS) from anchor A 1002 and transmitting the reference signal (PRS) to the target UE 104. If necessary, the RSTD group can include multiple RSTD measurement instances in determining clock drift errors without an anchor-to-anchor procedure.

[0176] It should be understood that although Figure 11 illustrates two adjacent RSTD measurement instances of the anchor-to-anchor procedure (i.e., RSTD measurement instances 1110 and 1120), there may be one or more intermediate RSTD measurement instances without the anchor-to-anchor procedure if needed.

[0177] The clock drift error caused by the non-ideal synchronization between anchor A 1002 and moving anchor B 1006 can be identified as follows. As can be seen in Figure 11, Equation 7

[0178] Therefore, for non-ideal anchor synchronization, the baseline DL-TDOA algorithm for RSTD measurement example 1110 can be written as: Equation 8

[0179] If the time interval between the transmissions of PRS#1 and PRS#2 (configuration slot offset in milliseconds) is specified as TPRS#1-to-#2, then for ideal anchor synchronization, the baseline DL-TDOA algorithm can be written as: Equation 9

[0180] Therefore, the synchronization deviation can be determined by subtracting equations 8 and 9, thus obtaining: Δ. Equation 10

[0181] Similarly, for PRS#3 and PRS#4 in RSTD measurement example 1120, the synchronization deviation can be written as: Δ. Equation 11

[0182] Assuming the change in anchor synchronization deviation is solely due to clock drift (where eA is the error at anchor A 1002 and eB is the error at moving anchor B 1006), the synchronization deviations of PRS#3 and PRS#4 can be written as: Δ, Equation 12. Equation 13

[0183] Therefore, as can be seen in Equation 13, the clock drift error (eB-eA) is a function of the measurement, including the RxTx time difference () measured by the moving anchor B 1006 at time t1 in RSTD measurement example 1110 and the RxTx time difference () measured by the moving anchor B' 1006 at time t2 in RSTD measurement example 1120.

[0184] Given the clock drift error (eB-eA), additional RSTD measurement instances (e.g., RSTD measurement instance 1130) can be estimated without anchor-to-anchor procedures. For example, under the assumption of non-ideal synchronization between anchor A 1002 and moving anchor B 1006, at time t3, the DL-TDOA algorithm for RSTD measurement instance 1130 can be written as: Equation 14

[0185] Δ can be written as: , Equation 15

[0186] Therefore, when using a moving anchor (moving anchor B 1006) to measure a set of RSTDs over time, clock drift error mitigation requires only two RSTD measurement instances, illustrated in Figure 11 as RSTD measurement instances 1110 and 1120. One or more of the remaining RSTD measurement instances (illustrated in Figure 11 as RSTD measurement instance 1130) are not needed to determine clock drift error mitigation, thus eliminating the need for an anchor-to-anchor procedure.

[0187] It should be understood that the anchor-to-anchor procedure for generating the RxTx time difference for two corresponding PRS groups sent by anchor A 1002 and moving anchor B 1006 can be measured by moving anchor B 1006, as shown in Figure 11, or can be measured by anchor A 1002.

[0188] By way of example, Figure 12 illustrates an exemplary process 1200 of a TDOA procedure that uses time drift mitigation of a mobile anchor to improve the positioning accuracy of the location estimation of the target UE 104. The process 1200 shown in Figure 12 is similar to the process 1100 shown in Figure 11, but the RxTx time difference, denoted as , between receiving PRS#1 from the mobile anchor B 1006 (sent at time t1) and sending PRS#2 to the target UE 104, as illustrated in RSTD measurement instance 1210, can be measured by the fixed anchor A 1002, and the RxTx time difference, denoted as , between receiving PRS#3 from the mobile anchor B' 1006 (sent at time t2) and sending PRS#4 to the target UE 104, as illustrated in RSTD measurement instance 1220, can be measured by the fixed anchor A 1002, without needing to measure or report the RxTx time difference in RSTD measurement instance 1230.

[0189] Figure 13 is an illustration of the reference signals (PRS) transmitted by anchor A 1002 and mobile anchor B 1006 to generate a set of RSTD measurements using clock drift error mitigation as discussed in Figure 11. The set of RSTD measurements generated for the target UE 104 over time can be defined by a first PRS instance group 1302 of the PRS transmitted by fixed anchor A 1002 and a second PRS instance group 1304 of the PRS transmitted by mobile anchor B 1006, wherein the corresponding PRS pairs from the first PRS instance group 1302 and the second PRS instance group 1304 generate RSTD measurement instances 1310, 1320, 1330 and 1340 identified by dotted-line squares.

[0190] As discussed above, clock drift error mitigation requires only two RSTD measurement instances. Therefore, for an RSTD group generated using mobile anchor B 1006, only two anchor-to-anchor measurements are required, namely the RxTx time difference between the two PRS from the first PRS instance group 1302 for the PRS from anchor A 1002 and the corresponding two PRS from the second PRS instance group 1304 for the PRS from mobile anchor B 1006 (e.g., in the PRS pairs in RSTD measurement instances 1310 and 1330), which should be measured and reported by mobile anchor B 1006 or fixed anchor A 1002 (e.g., to the location server or target UE 104), as shown in Figure 12.

[0191] The two PRS instances used for anchor-to-anchor RxTx time difference measurement should have the same RxTx timing error group (TEG) identifier (ID) so that differences in RxTx time difference measurement (e.g., can mitigate some additional group delay). Two PRSs sent by either of the two anchors in the two PRS instances (e.g., PRS#1 and PRS3 or PRS#2 and PRS#4 shown in Figure 11 or 12) should have the same Tx TEG ID, thus allowing the assumption that drift error increases linearly with isochronous adjustment, for example, without synchronization adjustment between PRS#1 and PRS#3 or between PRS#2 and PRS#4.

[0192] In some implementations, such as those shown in Figure 11 or Figure 12, the RSTD measurement group of the target UE 104 can be triggered by a network entity or a fixed anchor A 1002. This triggering can be based on a location request from the target UE 104 prior to triggering the RSTD measurement group. For example, the trigger message can indicate that a first PRS instance group (PRS instance group 1302 from anchor A 1002 in Figure 13) and a second PRS instance group (PRS instance group 1304 from mobile anchor B 1006 in Figure 13) of PRS resources will be associated with the RSTD measurement group. For example, in some implementations, the first PRS instance group from anchor A 1002 and the second PRS instance group from mobile anchor B 1006 selected for the RSTD measurement PRS instance group can have the same periodicity.

[0193] In addition, two RSTD measurement instances of anchor-to-anchor RxTx time difference measurement can be indicated in the trigger message. The two anchor-to-anchor RxTx time difference measurements measured by moving anchor B 1006 or anchor A 1002 can be reported to the location calculation entity (i.e., the target UE 104 or the location server 172 (e.g., LMF 270)).

[0194] PRS resources from mobile anchor B 1006 can be retained. For example, a PRS instance group (PRS instance group 1304 in Figure 13) of PRS resources sent by mobile anchor B 1006 can be retained by a network entity or fixed anchor A 1002. Furthermore, the PRS instance group (PRS instance group 1304 in Figure 13) of PRS resources sent by mobile anchor B 1006 can have a lifetime, such as a number of cycles.

[0195] Figure 14 illustrates a message flow 1400 of message passing between a location server 172, anchor A 1402, anchor B 1404, and target UE 104, for supporting UE TDOA positioning using RSTD measurements from a mobile anchor, as discussed herein. For example, location server 172 may be LMF 270. In one implementation, anchor A 1402 may be a fixed anchor A 1002, while anchor B 1404 may be a mobile anchor B 1006 performing two anchor-to-anchor RxTx time difference measurements, as shown in Figure 11. In another implementation, anchor A 1402 may be a mobile anchor B 1006 performing two anchor-to-anchor RxTx time difference measurements, while anchor B 1404 may be a fixed anchor A 1002, as shown in Figure 12. For ease of reference in Figure 14, anchor A 1402 will be assumed to be a fixed anchor, and anchor B 1406 will be assumed to be a moving anchor. However, it should be understood that anchor A 1402 can be a moving anchor and anchor B can be a fixed anchor as shown in Figure 14 without loss of generality. It should be understood that Figure 14 illustrates messages related to the TDOA positioning of a target UE using the RSTD measurements discussed herein, but message flow 1400 may include additional messages, including general LPP messages, or fewer messages. For example, message exchanges for establishing positioning communication and determining the capabilities of UE 104 may be performed, or auxiliary information may be omitted.

[0196] At stage 1, location server 172 may send auxiliary data to UE 104, for example, in an LPP auxiliary data message. The auxiliary data may include PRS configuration information for anchors 1402 and 1406, and may identify fixed anchor 1402 and mobile anchor 1406. The auxiliary data may also include, for example, the location of the fixed anchor used for UE-based positioning procedures. Location server 172 may provide PRS configuration information from anchor A 1402 and anchor B 1406 that will be received by target UE 104.

[0197] At stage 2, location server 172 can send PRS configuration information to anchors 1402 and 1406 for transmission to target UE 104. Location server 172 can further provide anchor B 1406 with PRS configuration information for PRS resources to be sent by anchor A 1402 and detected by anchor B 1406. For example, location server 172 can indicate the PRS instance group of the PRS resources to be sent by anchor A 1402 and the PRS instance group of the resources to be sent by anchor B 1406, which are associated with the RSTD measurement group of UE 104. For example, the PRS instance group of PRS resources can be selected to have the same periodicity. Location server 172 can indicate the RSTD measurement instance of anchor-to-anchor RxTx time difference measurement performed by anchor B 1406. PRS in anchor-to-anchor RxTx time difference measurement can have the same RxTx TEG ID. Furthermore, PRS sent by a fixed anchor entity (e.g., anchor A 1402 for measuring the RxTx time difference between two anchors) can have the same Tx TEG ID, and / or PRS sent by a mobile anchor entity (e.g., anchor B 1406 for measuring the RxTx time difference between two anchors) can have the same Tx TEG ID. A group of PRS instances for the PRS resources sent by mobile anchor B 1406 can be retained by a network entity (e.g., location server 172) or fixed anchor A 1402. Additionally, the group of PRS instances for the PRS resources sent by mobile anchor B 1406 can have a lifetime, such as the number of cycles. PRS sent by mobile anchor B 1406 can be retained by fixed anchor A 1402. In some implementations, instead of location server 172, PRS configuration information can be sent by fixed anchor A 1402.

[0198] At stage 3, location server 172 may send a location information request to UE 104, for example, in an LPP request location information message. For example, the location information request or another message may trigger an RSTD measurement group for the target UE 104. In some implementations, a fixed anchor entity (e.g., anchor A 1402) may send a trigger message to the target UE 104. The trigger request may respond to a location request from the target UE 104. In some implementations, the trigger message (e.g., the location information request) may provide PRS resource information from the anchor entity for PRS resources to be measured for the RSTD measurement group. For example, the request may be an RSTD measurement for UE-assisted positioning or a location estimation (and optional RSTD measurement) for UE-based positioning.

[0199] Blocks 1410, 1420, and 1430 illustrate different RSTD measurement instances over time, during which the position of the moving anchor B 1406 relative to the target UE 104 changes, and thus the moving anchor B 1406 acts as multiple virtual anchors for the RSTD measurement instances. The moving anchor B 1406 can perform and report anchor-to-anchor RxTx time difference measurements in only two RSTD measurement instances (as shown in RSTD 1410 and 1420) for clock drift error mitigation.

[0200] At stage 4 in RSTD measurement instance 1410, anchor 1402 sends a reference signal (e.g., DL PRS) to target UE 104 and anchor 1406. Sending PRS to anchor 1406 may occur simultaneously with sending PRS to target UE 104, or it may occur after a transmission delay that is measured and reported and can be used for RSTD measurement.

[0201] At stage 5 of RSTD measurement instance 1410, anchor 1406 sends a reference signal (e.g., SL or DL ​​PRS) to target UE 104.

[0202] At phase 6 of RSTD measurement instance 1410, anchor 1406 measures the first RxTx time difference between receiving the PRS from anchor 1402 in phase 4 and transmitting the PRS to target UE 104 in phase 5. Anchor 1406 may further record the transmission time T_tx of the PRS transmitted to target UE 104 in phase 5. Anchor 1406 also records its position during RSTD measurement instance 1410, which may be determined, for example, based on precise GNSS and / or ground measurements consistent with RSTD measurement instance 1410, or may be based on a previously determined precise position (e.g., GNSS and / or ground measurements) updated using sensor information, as discussed above (e.g., in dead reckoning procedures).

[0203] In phase 7 of RSTD measurement instance 1420, anchor 1402 sends a reference signal (e.g., DL PRS) to target UE 104 and anchor 1406. Similar to phase 4, sending a PRS to anchor 1406 may occur simultaneously with sending a PRS to target UE 104, or it may occur after a transmission delay that is measured and reported and can be used for RSTD measurement.

[0204] At stage 8 of RSTD measurement instance 1420, anchor 1406 sends a reference signal (e.g., SL or DL ​​PRS) to target UE 104, similar to stage 5.

[0205] At phase 9 of RSTD measurement instance 1420, anchor 1406 measures the second RxTx time difference between receiving the PRS from anchor 1402 in phase 7 and transmitting the PRS to the target UE 104 in phase 8. Anchor 1406 may further record the transmission time T_tx of the PRS transmitted to the target UE 104 in phase 8. Anchor 1406 also records its position during RSTD measurement instance 1420, similar to phase 6, which may be determined, for example, using precise GNSS and / or ground measurements or dead reckoning with sensor information.

[0206] In phase 10 of RSTD measurement instance 1430, anchor 1402 sends a reference signal (e.g., DL PRS) to target UE 104. The PRS sent in phase 10 does not need to be sent to anchor 1406 or received by anchor 1406.

[0207] At phase 11 of RSTD measurement instance 1430, anchor 1406 transmits a reference signal (e.g., SL or DL ​​PRS) to target UE 104, similar to phase 8. Unlike RSTD measurement instances 1410 and 1420, in RSTD 1430, anchor 1406 does not need to measure the RxTx time difference between receiving the PRS from anchor 1402 and transmitting the PRS to target UE 104 in phase 10. Anchor 1406 may further record the transmission time T_tx of the PRS transmitted to target UE 104 in phase 11. However, anchor 1406 may additionally record its position during RSTD measurement instance 1430, similar to phase 6, which may be determined, for example, using precise GNSS and / or ground measurements or dead reckoning with sensor information.

[0208] At stage 12, UE 104 performs location measurements using the DL PRS received from anchor A 1402 and anchor B 1406 in stages 4 and 5, 7 and 8, and 10 and 11. For example, the location measurements include an indication of the difference between the received Rx time of the PRS from anchor A 1402 and the received time of the PRS from anchor B 1404 at the target UE 104, such as the time difference (T_Rx-Rx), for example, expressed as , and (as shown in Figures 11 and 13), or the received time.

[0209] At stage 13, anchor B 1406 provides a measurement report to the location calculation entity, namely location server 172 or, in some implementations (illustrated with dashed lines), target UE 104. The measurement report may include RxTx time difference measurements from RSTD measurement instances 1410 and 1420, transmission time T_tx of PRS transmitted in stages 5, 8, and 11, and location information of anchor B 1406 (assuming anchor B 1406 is a moving anchor) (e.g., absolute location for each time instance, such as stages 5, 8, and 11).

[0210] At stage 14, anchor A 1402 provides a measurement report to the location calculation entity, namely the location server 172 or, in some implementations (illustrated with dashed lines), the target UE 104. The measurement report may include the transmission time T_tx of the PRS transmitted in stages 4, 7, and 10. In some implementations, anchor A 1402 may provide its location if the location of anchor A 1402 is not provided in the auxiliary data in stage 1 (or if anchor A 1402 is a moving anchor).

[0211] At stage 15, as shown by the dashed square, for UE-based positioning, the target UE 104 may generate a position estimate using TDOA (as discussed herein), positioning measurements performed as stage 12, and measurement reports received from anchor B 1406 and anchor A 1402 in stages 13 and 14. For example, target UE 104 can determine the time of flight (ToF) between anchor A 1402 and anchor B 1406 for each RSTD measurement instance 1410, 1420, 1430 based on auxiliary data and the reported location of the moving anchor (e.g., in phase 13, using the clock drift error (eB-eA) of the measurements (including the RxTx time difference measured by anchor B 1406)), as shown in Equation 13, and can determine the TDOA using the measurements and clock drift error (eB-eA) from RSTD measurement instances 1410, 1420, and 1430, as shown in Equations 8 and 14, 15. Using the known location of the anchor (e.g., as received in the auxiliary data in phase 1) and / or the determined TDOA, multi-point positioning can be used to estimate the location of UE 104.

[0212] At stage 16, UE 104 sends location information to location server 172 in the LPP Location Information Provided message. For example, the location information may include a location estimate determined in stage 15 and / or a location measurement determined in stage 12, such as an indication of the difference between the time the PRS is received from anchor A 1402 and the time the PRS is received from anchor 1406. For example, the location information may include the difference in the PRS reception time or the reception time.

[0213] At stage 17, location server 172 may determine a location estimate of target UE 104 based on location information received in the messages of stages 13, 14 and 16, or verify a location estimate from UE 104. Location server 172 may use TDOA to determine the location of target UE 104, as discussed herein. For example, the location server 172 can determine the time of flight (ToF) between anchor A 1402 and anchor B 1406 for each RSTD measurement instance 1410, 1420, 1430 based on the known location of the fixed anchor and the reported location of the moving anchor (e.g., from stage 13, using the clock drift error (eB-eA) of the measurements (including the RxTx time difference measured by anchor B 1406) as shown in Equation 13), and determine the time-of-flight (TDOA) using the measurements and clock drift error (eB-eA) from RSTD measurement instances 1410, 1420, and 1430, as shown in Equations 7 and 14, 15. Using the known location of the anchor and the determined TDOA, multi-point positioning can be used to estimate the location of UE 104.

[0214] Figure 15 illustrates a flowchart of an exemplary process 1500 for supporting the operation of a location estimation entity for determining the location of a target UE. In one implementation, the process may be performed by a location server, such as location server 172 shown in Figure 1A or LMF 270 or SLP 268 shown in Figure 2B. In one implementation, the process may be performed by the target UE (e.g., target UE 104 shown in Figure 1A).

[0215] At block 1502, the position estimation entity can obtain a set of Reference Signal Time Difference (RSTD) measurements for the target UE, including at least three RSTD measurements generated by the target UE at different times. Each RSTD measurement in this measurement set is generated using a Position Reference Signal (PRS) from a first PRS instance group sent by a fixed anchor entity and a corresponding PRS from a second PRS instance group sent by a moving anchor entity, for example as shown in stages 12 and 16 of Figures 10 to 13 and 14. For example, the fixed anchor entity may be anchor A 1002 shown in Figures 10 to 13 or anchor A 1402 or anchor B 1406 in Figure 14. For example, the moving anchor entity may be anchor B 1006 shown in Figures 10 to 13 or anchor A 1402 or anchor B 1406 in Figure 14. A component for obtaining a set of Reference Signal Time Difference (RSTD) measurements for a target UE, comprising at least three RSTD measurements generated by the target UE at different times, wherein each RSTD measurement is generated using a Position Reference Signal (PRS) from a first PRS instance group transmitted from a fixed anchor entity and a corresponding PRS from a second PRS instance group transmitted from a mobile anchor entity. The RSTD measurement may include at least one WWAN transceiver 310 or at least one short-range radio transceiver 320 and at least one processor 332 (such as the PRS module 342 in UE 302 shown in Figure 3A) having executable code or software instructions in dedicated hardware or implementation memory 340, or at least one network interface 390 and at least one processor 394 (such as the PRS module 398 in network entity 306 shown in Figure 3C) having executable code or software instructions in dedicated hardware or implementation memory 396.

[0216] At block 1504, the location estimation entity can obtain at least two anchor-to-anchor receive-to-transmit (RxTx) time difference measurements, wherein each anchor-to-anchor RxTx time difference measurement is associated with a PRS from a first PRS instance group and a corresponding PRS from a second PRS instance group, wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the RSTD measurement group, as shown, for example, in stages 6, 9 and 13 of Figures 10 to 13 and Figures 14. Components for obtaining at least two anchor-to-anchor receive-to-transmit (RxTx) time difference measurements, wherein each anchor-to-anchor RxTx time difference measurement is associated with a PRS from a first PRS instance group and a corresponding PRS from a second PRS instance group, wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the RSTD measurement group may include at least one WWAN transceiver 310 or at least one short-range radio transceiver 320 and at least one processor 332 (such as PRS module 342 in UE 302 shown in Figure 3A) having executable code or software instructions in dedicated hardware or implementation memory 340 or at least one network interface 390 and at least one processor 394 (such as PRS module 398 in network entity 306 shown in Figure 3C) having executable code or software instructions in dedicated hardware or implementation memory 396.

[0217] At block 1506, the location estimation entity may determine the location estimate of the target UE based on the RSTD measurement set and at least two anchor-to-anchor RxTx time difference measurements, for example as shown in phase 15 or phase 17 of Figures 10 to 13 and 14. The components used to determine the location estimate of the target UE based on the RSTD measurement set and at least two anchor-to-anchor RxTx time difference measurements may include at least one WWAN transceiver 310 or at least one short-range radio transceiver 320 and at least one processor 332 (such as the PRS module 342 in UE 302 shown in Figure 3A) having executable code or software instructions in dedicated hardware or implementation memory 340, or at least one network interface 390 and at least one processor 394 (such as the PRS module 398 in network entity 306 shown in Figure 3C) having executable code or software instructions in dedicated hardware or implementation memory 396.

[0218] In one implementation, each anchor-to-anchor RxTx time difference measurement is one of the measurements performed by the moving anchor entity based on the reception of the first PRS in the first PRS instance group and the transmission of the second PRS in the second PRS instance group, or by the fixed anchor entity based on the reception of the third PRS in the second PRS instance group and the transmission of the fourth PRS in the first PRS instance group, for example as discussed in Figures 11 and 12 respectively, and in Figure 14 including phases 6 and 9.

[0219] In one implementation, the PRS from the first PRS instance group and the corresponding PRS from the second PRS instance group in at least two anchor-to-anchor RxTx time difference measurements have the same RxTx timing error group identifier, for example as discussed in stage 2 of Figures 13 and 14.

[0220] In one implementation, the PRS sent by the fixed anchor entity in the first PRS instance group associated with at least two anchor-to-anchor RxTx time difference measurements have the same transmission timing error group identifier, such as that discussed in stage 2 of Figures 13 and 14.

[0221] In one implementation, the PRS sent by the mobile anchor entity in the second PRS instance group associated with at least two anchor-to-anchor RxTx time difference measurements have the same transmission timing error group identifier, such as that discussed in stage 2 of Figures 13 and 14.

[0222] In one implementation, the RSTD measurement group for the target UE is triggered by a location server or a fixed anchor entity, as discussed in stage 3 of Figures 13 and 14. In one implementation, the RSTD measurement group for the target UE may be triggered, for example, based on a location request from the target UE, as discussed in stage 3 of Figures 13 and 14. In one implementation, a trigger message sent to the target UE to trigger the RSTD measurement group for the target UE may indicate PRS resources in a first PRS instance group and a second PRS instance group, as discussed in stage 3 of Figures 13 and 14. In one implementation, the PRS resources in the first PRS instance group and the second PRS instance group may have the same periodicity, as discussed in stage 2 of Figures 13 and 14. In one implementation, the trigger message indicates PRS resources in a first PRS instance group for at least two anchor-to-anchor RxTx time difference measurements, as discussed in stage 2 of Figures 13 and 14.

[0223] In one implementation, the position estimation entity is a position server, and wherein at least two anchor-to-anchor RxTx time difference measurements are received from one of the fixed anchor entity and the moving anchor entity, for example as discussed in stages 13 and 17 of Figure 14.

[0224] In one implementation, the location estimation entity is the target UE, and wherein at least two anchor-to-anchor RxTx time difference measurements are received from one of the fixed anchor entity and the moving anchor entity, as discussed, for example, in stages 13 and 15 of Figure 14.

[0225] In one implementation, the PRS in the second PRS instance group for the RSTD measurement group sent by the moving anchor entity is retained by the fixed anchor entity, for example as discussed in stage 2 of Figures 13 and 14.

[0226] In one implementation, the number of time periods for the PRS in the second PRS instance group for the RSTD measurement group sent by the mobile anchor entity is limited, for example as discussed in stage 2 of Figures 13 and 14.

[0227] Throughout this specification, references to "an instance," "an example," "some instances," or "exemplary implementation" refer to a specific feature, structure, or characteristic of the description relating to a feature and / or instance, which may be included in at least one feature and / or instance of the claimed object. Therefore, the appearance of the phrases "in an instance," "one example," "in some instances," or "in some implementations," or other similar phrases throughout this specification does not necessarily refer to the same feature, instance, and / or limitation. Furthermore, a particular feature, structure, or characteristic may be combined in one or more instances and / or features.

[0228] Some portions of the detailed description included herein are presented as a symbolic representation of an algorithm or operation of binary bit signals stored in the memory of a particular device or dedicated computing device or platform. In the context of this particular specification, the term particular device or similar, once a program is designed to perform a particular operation according to instructions from program software, includes a general-purpose computer. Algorithm descriptions or symbolic representations are examples of techniques used by those skilled in signal processing or related fields to convey the essence of their work to others skilled in the art. Algorithms herein are generally considered to be self-consistent sequences of operations or similar signal processing that lead to desired results. In this case, the operation or processing involves the physical manipulation of physical quantities. Generally, although not always, such quantities may take the form of electrical or magnetic signals that can be stored, transmitted, combined, compared, or otherwise manipulated. Primarily for reasons of common use, it has proven convenient to sometimes refer to such signals as bits, data, values, elements, symbols, characters, terms, numerical values, digits, or the like. However, it should be understood that all such or similar terms are associated with appropriate physical quantities and are merely convenient labels. Unless otherwise specified, it will be apparent from the discussion herein that throughout this specification, the use of terms such as "processing," "operation," "calculation," "determining," or similar terms refers to the actions or processes of a specific device (such as a dedicated computer, dedicated computing device, or similar dedicated electronic computing device). Therefore, in the context of this specification, a dedicated computer or similar dedicated electronic computing device capable of manipulating or converting signals generally refers to physical electronic or magnetic quantities in the memory, registers, or other information storage devices, transmission devices, or display devices of the dedicated computer or similar dedicated electronic computing device.

[0229] In the foregoing detailed description, numerous specific details have been set forth to provide a thorough understanding of the claimed subject matter. However, those skilled in the art will understand that the claimed subject matter can be practiced without such specific details. In other instances, methods and apparatus known to those skilled in the art have not been described in detail so as not to obscure the claimed subject matter.

[0230] The terms "and," "or," and "and / or" as used herein may have a variety of meanings, which are expected to depend at least in part on the context in which they are used. Generally, "or," when used in an associative list such as A, B, or C, means A, B, and C (in an inclusive sense) and A, B, or C (in an exclusive sense). Furthermore, the term "one or more" as used herein may be used to describe any feature, structure, or characteristic in the singular, or to describe a plurality or some other combination of features, structures, or characteristics. Although it should be noted that this is merely an illustrative example, and the object of the claim is not limited to this example.

[0231] Although the currently considered exemplary features have been illustrated and described, those skilled in the art will understand that various other modifications can be made and equivalents can be substituted without departing from the claimed subject matter. Furthermore, many modifications can be made to adapt specific situations to the teachings of the claimed subject matter without departing from the central concepts described herein.

[0232] In view of this description, embodiments may include different combinations of features. The following numbered clauses describe embodiments:

[0233] Clause 1. A method for operating a location estimation entity for determining the location of a target user equipment (UE), comprising: obtaining a set of reference signal time difference (RSTD) measurements of the target UE, including at least three RSTD measurements generated by the target UE at different times, wherein each of the RSTD measurement sets is generated using a positioning reference signal (PRS) transmitted from a first PRS instance group by a fixed anchor entity and a corresponding PRS transmitted from a second PRS instance group by a mobile anchor entity; obtaining at least two anchor-to-anchor receive-to-transmit (RxTx) time difference measurements, wherein each anchor-to-anchor RxTx time difference measurement is associated with a PRS from the first PRS instance group and a corresponding PRS from the second PRS instance group, wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the RSTD measurement set; and determining a location estimate of the target UE based on the RSTD measurement set and the at least two anchor-to-anchor RxTx time difference measurements.

[0234] Clause 2. The method according to Clause 1, wherein each anchor-to-anchor RxTx time difference measurement is one of the measurements performed by the moving anchor entity based on the reception of the first PRS in the first PRS instance group and the transmission of the second PRS in the second PRS instance group, or by the fixed anchor entity based on the reception of the third PRS in the second PRS instance group and the transmission of the fourth PRS in the first PRS instance group.

[0235] Clause 3. The method according to any one of Clauses 1-2, wherein the PRS from the first PRS instance group and the corresponding PRS from the second PRS instance group in at least two anchor-to-anchor RxTx time difference measurements have the same RxTx timing error group identifier.

[0236] Clause 4. The method according to any one of Clauses 1-3, wherein the PRS sent by the fixed anchor entity in the first PRS instance group associated with at least two anchor-to-anchor RxTx time difference measurements has the same transmission timing error group identifier.

[0237] Clause 5. The method according to any one of Clauses 1-4, wherein the PRS sent by the mobile anchor entity in the second PRS instance group associated with at least two anchor-to-anchor RxTx time difference measurements has the same transmission timing error group identifier.

[0238] Clause 6. The method of any one of Clauses 1-5, wherein the RSTD measurement group of the target UE is triggered by a location server or a fixed anchor entity.

[0239] Clause 7. The method according to Clause 6, wherein an RSTD measurement group for the target UE is triggered based on a location request from the target UE.

[0240] Clause 8. The method according to any one of Clauses 6-7, wherein a trigger message sent to the target UE to trigger the RSTD measurement group of the target UE indicates PRS resources in the first PRS instance group and the second PRS instance group.

[0241] Article 9. The method of Article 8, wherein the PRS resources in the first PRS instance group and the second PRS instance group have the same periodicity.

[0242] Clause 10. The method of any one of Clauses 6-9, wherein the triggering message indicates the PRS resource in the first PRS instance group for at least two anchor-to-anchor RxTx time difference measurements.

[0243] Clause 11. The method according to any one of Clauses 1-10, wherein the position estimation entity is a position server, and wherein at least two anchor-to-anchor RxTx time difference measurements are received from one of the fixed anchor entity and the moving anchor entity.

[0244] Clause 12. The method according to any one of Clauses 1-10, wherein the location estimation entity is the target UE, and wherein at least two anchor-to-anchor RxTx time difference measurements are received from one of the fixed anchor entity and the moving anchor entity.

[0245] Clause 13. The method according to any one of Clauses 1-12, wherein the PRS in the second PRS instance group for the RSTD measurement group sent by the moving anchor entity is retained by the fixed anchor entity.

[0246] Clause 14. The method according to any one of Clauses 1-13, wherein the PRS in the second PRS instance group for the RSTD measurement group sent by the mobile anchor entity is limited to the number of time periods.

[0247] Clause 15. A location estimation entity configured to determine the location of a target user equipment (UE), comprising: a memory; at least one external interface; and at least one processor communicatively coupled to the memory and the at least one external interface, the at least one processor being configured to: acquire a set of reference signal time difference (RSTD) measurements of the target UE, including at least three RSTD measurements generated by the target UE at different times, wherein a location reference signal (PRS) from a first PRS instance group transmitted by a fixed anchor entity and a location reference signal transmitted by a mobile anchor entity are used. The corresponding PRS from the second PRS instance group is used to generate RSTD measurements for each of the RSTD measurement groups; at least two anchor-to-anchor receive-to-transmit (RxTx) time difference measurements are obtained, wherein each anchor-to-anchor RxTx time difference measurement is associated with a PRS from the first PRS instance group and a corresponding PRS from the second PRS instance group, wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the RSTD measurement group; and the location estimate of the target UE is determined based on the RSTD measurement group and the at least two anchor-to-anchor RxTx time difference measurements.

[0248] Clause 16. The position estimation entity pursuant to Clause 15, wherein each anchor-to-anchor RxTx time difference measurement is one of the measurements performed by the moving anchor entity based on the reception of the first PRS in the first PRS instance group and the transmission of the second PRS in the second PRS instance group, or by the fixed anchor entity based on the reception of the third PRS in the second PRS instance group and the transmission of the fourth PRS in the first PRS instance group.

[0249] Clause 17. A location estimation entity according to any one of Clauses 15-16, wherein the PRS from the first PRS instance group and the corresponding PRS from the second PRS instance group in at least two anchor-to-anchor RxTx time difference measurements have the same RxTx time series error group identifier.

[0250] Clause 18. A location estimation entity pursuant to any of Clauses 15-17, wherein the PRS transmitted by the fixed anchor entity in a first PRS instance group associated with at least two anchor-to-anchor RxTx time difference measurements has the same transmission timing error group identifier.

[0251] Clause 19. A location estimation entity pursuant to any of Clauses 15-18, wherein the PRS transmitted by the moving anchor entity in a second PRS instance group associated with at least two anchor-to-anchor RxTx time difference measurements has the same transmission timing error group identifier.

[0252] Clause 20. A location estimation entity pursuant to any of Clauses 15-19, wherein the RSTD measurement group of the target UE is triggered by a location server or a fixed anchor entity.

[0253] Clause 21. Location estimation entity pursuant to Clause 20, wherein an RSTD measurement group for the target UE is triggered based on a location request from the target UE.

[0254] Clause 22. A location estimation entity pursuant to any of Clauses 20-21, wherein a trigger message sent to the target UE to trigger the RSTD measurement group of the target UE indicates PRS resources in the first PRS instance group and the second PRS instance group.

[0255] Article 23. Entities whose location is estimated in accordance with Article 22, wherein the PRS resources in the first PRS instance group and the second PRS instance group have the same periodicity.

[0256] Clause 24. A location estimation entity pursuant to any of Clauses 20-23, wherein a triggering message indicates a PRS resource in a first PRS instance group for at least two anchor-to-anchor RxTx time difference measurements.

[0257] Clause 25. A location estimation entity according to any one of Clauses 15-24, wherein the location estimation entity is a location server, and wherein at least one external interface includes at least one network interface and receives at least two anchor-to-anchor RxTx time difference measurements from one of a fixed anchor entity and a mobile anchor entity.

[0258] Clause 26. A location estimation entity according to any one of Clauses 15-24, wherein the location estimation entity is a target UE, and wherein at least one external interface includes at least one radio transceiver, and receives at least two anchor-to-anchor RxTx time difference measurements from one of a fixed anchor entity and a mobile anchor entity.

[0259] Clause 27. A location estimation entity pursuant to any of Clauses 15-26, wherein the PRS in the second PRS instance group for the RSTD measurement group sent by the moving anchor entity is retained by the fixed anchor entity.

[0260] Clause 28. A location estimation entity pursuant to any of Clauses 15-27, wherein the PRS sent by the moving anchor entity for the second PRS instance group of the RSTD measurement group is limited to the number of time periods.

[0261] Clause 29. A location estimation entity configured to determine the location of a target user equipment (UE), comprising: means for obtaining a set of reference signal time difference (RSTD) measurements of the target UE, including at least three RSTD measurements generated by the target UE at different times, wherein each RSTD measurement of the RSTD measurement set is generated using a positioning reference signal (PRS) from a first PRS instance group transmitted by a fixed anchor entity and a corresponding PRS from a second PRS instance group transmitted by a mobile anchor entity; means for obtaining at least two anchor-to-anchor receive-to-transmit (RxTx) time difference measurements, wherein each anchor-to-anchor RxTx time difference measurement is associated with a PRS from the first PRS instance group and a corresponding PRS from the second PRS instance group, wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the RSTD measurement set; and means for determining a location estimate of the target UE based on the RSTD measurement set and the at least two anchor-to-anchor RxTx time difference measurements.

[0262] Clause 30. A location estimation entity pursuant to Clause 29, wherein each anchor-to-anchor RxTx time difference measurement is one of a measurement performed by a moving anchor entity based on the reception of a first PRS in a first PRS instance group and the transmission of a second PRS in a second PRS instance group, or by a fixed anchor entity based on the reception of a third PRS in a second PRS instance group and the transmission of a fourth PRS in a first PRS instance group.

[0263] Clause 31. A location estimation entity pursuant to any of Clauses 29-30, wherein the PRS from the first PRS instance group and the corresponding PRS from the second PRS instance group in at least two anchor-to-anchor RxTx time difference measurements have the same RxTx time series error group identifier.

[0264] Clause 32. A location estimation entity pursuant to any of Clauses 29-31, wherein the PRS transmitted by the fixed anchor entity in a first PRS instance group associated with at least two anchor-to-anchor RxTx time difference measurements has the same transmission timing error group identifier.

[0265] Clause 33. A location estimation entity pursuant to any of Clauses 29-32, wherein the PRS transmitted by the moving anchor entity in a second PRS instance group associated with at least two anchor-to-anchor RxTx time difference measurements has the same transmission timing error group identifier.

[0266] Clause 34. A location estimation entity pursuant to any of Clauses 29-33, wherein the RSTD measurement group of the target UE is triggered by a location server or a fixed anchor entity.

[0267] Clause 35. Location estimation entity pursuant to Clause 34, wherein an RSTD measurement group for the target UE is triggered based on a location request from the target UE.

[0268] Clause 36. A location estimation entity pursuant to any of Clauses 34-35, wherein a trigger message sent to the target UE to trigger the RSTD measurement group of the target UE indicates PRS resources in the first PRS instance group and the second PRS instance group.

[0269] Clause 37. Location-estimated entities in accordance with Clause 36, wherein the PRS resources in the first PRS instance group and the second PRS instance group have the same periodicity.

[0270] Clause 38. A location estimation entity pursuant to any of Clauses 34-37, wherein a triggering message indicates a PRS resource in a first PRS instance group for at least two anchor-to-anchor RxTx time difference measurements.

[0271] Clause 39. A location estimation entity pursuant to any one of Clauses 29-38, wherein the location estimation entity is a location server, and wherein at least two anchor-to-anchor RxTx time difference measurements are received from one of the fixed anchor entity and the moving anchor entity.

[0272] Clause 40. A location estimation entity pursuant to any one of Clauses 29-38, wherein the location estimation entity is a target UE, and wherein at least two anchor-to-anchor RxTx time difference measurements are received from one of the fixed anchor entity and the moving anchor entity.

[0273] Clause 41. A location estimation entity pursuant to any of Clauses 29-40, wherein the PRS in the second PRS instance group for the RSTD measurement group sent by the moving anchor entity is retained by the fixed anchor entity.

[0274] Clause 42. A location estimation entity pursuant to any of Clauses 29-41, wherein the PRS sent by the moving anchor entity for the second PRS instance group of the RSTD measurement group is limited to the number of time periods.

[0275] Clause 43. A non-transitory storage medium including code stored thereon, the code being operable to configure at least one processor in a location estimation entity for determining the location of a target user equipment (UE), the code including instructions to: obtain a set of reference signal time difference (RSTD) measurements of the target UE, including at least three RSTD measurements generated by the target UE at different times, wherein a location reference signal (PRS) from a first PRS instance group transmitted by a fixed anchor entity and a second PRS instance group transmitted by a mobile anchor entity are used. The corresponding PRS of the S instance group is used to generate RSTD measurements for each of the RSTD measurement groups; at least two anchor-to-anchor receive-to-transmit (RxTx) time difference measurements are obtained, wherein each anchor-to-anchor RxTx time difference measurement is associated with a PRS from the first PRS instance group and a corresponding PRS from the second PRS instance group, wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the RSTD measurement group; and the location estimate of the target UE is determined based on the RSTD measurement group and the at least two anchor-to-anchor RxTx time difference measurements.

[0276] Clause 44. The non-transitory storage medium pursuant to Clause 43, wherein each anchor-to-anchor RxTx time difference measurement is one of the measurements performed by the moving anchor entity based on the reception of the first PRS in the first PRS instance group and the transmission of the second PRS in the second PRS instance group, or by the fixed anchor entity based on the reception of the third PRS in the second PRS instance group and the transmission of the fourth PRS in the first PRS instance group.

[0277] Clause 45. A non-transitory storage medium pursuant to any of Clauses 43-44, wherein the PRS from the first PRS instance group and the corresponding PRS from the second PRS instance group in at least two anchor-to-anchor RxTx time difference measurements have the same RxTx timing error group identifier.

[0278] Clause 46. A non-transitory storage medium pursuant to any of Clauses 43-45, wherein the PRS transmitted by a fixed anchor entity in a first PRS instance group associated with at least two anchor-to-anchor RxTx time difference measurements has the same transmission timing error group identifier.

[0279] Clause 47. A non-transitory storage medium pursuant to any of Clauses 43-46, wherein the PRS transmitted by the mobile anchor entity in a second PRS instance group associated with at least two anchor-to-anchor RxTx time difference measurements has the same transmission timing error group identifier.

[0280] Clause 48. A non-transitory storage medium pursuant to any of Clauses 43-47, wherein the RSTD measurement group of the target UE is triggered by a location server or a fixed anchor entity.

[0281] Clause 49. Non-transitory storage media pursuant to Clause 48, wherein an RSTD measurement group for the target UE is triggered based on a location request from the target UE.

[0282] Clause 50. A non-transitory storage medium pursuant to any of Clauses 48-49, wherein a trigger message sent to the target UE to trigger the RSTD measurement group of the target UE indicates PRS resources in the first PRS instance group and the second PRS instance group.

[0283] Clause 51. Non-transitory storage media pursuant to Clause 50, wherein the PRS resources in the first PRS instance group and the second PRS instance group have the same periodicity.

[0284] Clause 52. A non-transitory storage medium pursuant to any of Clauses 48-51, wherein the triggering message indicates a PRS resource in a first PRS instance group for at least two anchor-to-anchor RxTx time difference measurements.

[0285] Clause 53. A non-transitory storage medium pursuant to any of Clauses 43-52, wherein the location estimation entity is a location server, and wherein at least two anchor-to-anchor RxTx time difference measurements are received from one of the fixed anchor entity and the moving anchor entity.

[0286] Clause 54. A non-transitory storage medium pursuant to any of Clauses 43-52, wherein the location estimation entity is the target UE, and wherein at least two anchor-to-anchor RxTx time difference measurements are received from one of the fixed anchor entity and the mobile anchor entity.

[0287] Clause 55. A non-transitory storage medium pursuant to any of Clauses 43-54, wherein the PRS in the second PRS instance group for the RSTD measurement group sent by the mobile anchor entity is retained by the fixed anchor entity.

[0288] Clause 56. A non-transitory storage medium pursuant to any of Clauses 43-55, wherein the PRS in the second PRS instance group for the RSTD measurement group sent by the mobile anchor entity is limited to the number of time periods.

[0289] Therefore, the object of protection sought is not limited to the specific instance disclosed, but may also include all forms that fall within the scope of the appended claim and its equivalents. [Simplified Explanation of the Diagram]

[0010] The accompanying drawings are provided to help describe the various forms of this case, and the drawings are provided only to illustrate the forms and not to limit them.

[0011] Figure 1A illustrates an example wireless communication system according to the present case.

[0012] Figure 1B shows the architecture of the base station nodes that can be found in Figure 1A.

[0013] Figures 2A and 2B illustrate an example wireless network structure according to the present case.

[0014] Figures 3A to 3C are simplified block diagrams of several example states of components that can be used in user equipment (UE), base stations and network entities respectively, and are configured to support the communications taught herein.

[0015] Figures 4A to 4D are diagrams illustrating the example frame structure and channels within the frame structure according to the present case.

[0016] Figure 5 is a diagram of example location reference signal (PRS) resource sets with different time gaps according to the state of this case.

[0017] Figure 6 illustrates an example of positioning based on traditional downlink (DL) time difference of arrival (TDoA).

[0018] Figure 7 illustrates an example of positioning based on traditional uplink (UL) TDoA.

[0019] Figure 8 illustrates the timing diagram of the TDOA measurement signals exchanged between the UE and the fixed anchor.

[0020] Figure 9 illustrates a timing diagram of TDOA measurement signals exchanged between the UE and the fixed anchor with improved accuracy.

[0021] Figure 10 illustrates a wireless communication system for a mobile anchor that can be used for TDOA measurement.

[0022] Figure 11 illustrates a timing diagram of TDOA measurement signals with improved accuracy, exchanged between the UE and the fixed and mobile anchors.

[0023] Figure 12 illustrates another timing diagram of TDOA measurement signals with improved accuracy, exchanged between the UE and the fixed anchor and the moving anchor.

[0024] Figure 13 illustrates the PRS sent by the fixed anchor and the moving anchor to generate a set of measurements for improving accuracy.

[0025] Figure 14 shows the message flow between the location server, the target UE, the fixed anchor and the moving anchor, which supports measurements for improved accuracy.

[0026] Figure 15 illustrates a flowchart of an exemplary process for supporting the operation of a location estimation entity for determining the location of a target UE as disclosed herein. [Biomaterial Storage]

[0291] 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 operating a location estimation entity to determine a location of a target user equipment (UE), comprising the steps of: obtaining a set of Reference Signal Time Difference (RSTD) measurements of the target UE, including at least three RSTD measurements generated by the target UE at different times, wherein each RSTD measurement of the RSTD measurement set is generated using a Positioning Reference Signal (PRS) transmitted from a first PRS instance group by a fixed anchor entity and a corresponding PRS transmitted from a second PRS instance group by a mobile anchor entity; obtaining at least two anchor-to-anchor receive-to-transmit (RxTx) time difference measurements, wherein each anchor-to-anchor RxTx time difference measurement is associated with the PRS from the first PRS instance group and the corresponding PRS from the second PRS instance group, wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the RSTD measurement set; and determining a location estimate of the target UE based on the RSTD measurement set and the at least two anchor-to-anchor RxTx time difference measurements.

2. The method as described in claim 1, wherein each anchor-to-anchor RxTx time difference measurement is one of a measurement performed by the moving anchor entity based on the reception of a first PRS in the first PRS instance group and the transmission of a second PRS in the second PRS instance group, or by the fixed anchor entity based on the reception of a third PRS in the second PRS instance group and the transmission of a fourth PRS in the first PRS instance group.

3. The method as described in claim 1, wherein the PRS from the first PRS instance group and the corresponding PRS from the second PRS instance group in the at least two anchor-to-anchor RxTx time difference measurements have the same RxTx timing error group identifier.

4. The method as described in claim 1, wherein the PRS sent by the fixed anchor entity in the first PRS instance group associated with the at least two anchor-to-anchor RxTx time difference measurements have the same transmission timing error group identifier.

5. The method as described in claim 1, wherein the PRS sent by the moving anchor entity in the second PRS instance group associated with the at least two anchor-to-anchor RxTx time difference measurements have the same transmission timing error group identifier.

6. The method as described in Request 1, wherein the RSTD measurement group of the target UE is triggered by a location server or by the fixed anchor entity.

7. The method as described in claim 6, wherein the RSTD measurement group for the target UE is triggered based on a location request from the target UE.

8. The method as described in claim 6, wherein a trigger message sent to the target UE to trigger the RSTD measurement group of the target UE indicates PRS resources in the first PRS instance group and the second PRS instance group.

9. The method as described in claim 8, wherein the PRS resources in the first PRS instance group and the second PRS instance group have the same periodicity.

10. The method as described in Request 6, wherein a trigger message indicates a PRS resource in the first PRS instance group for the at least two anchor-to-anchor RxTx time difference measurements.

11. The method as described in claim 1, wherein the position estimation entity is a position server, and wherein the at least two anchor-to-anchor RxTx time difference measurements are received from one of the fixed anchor entity and the moving anchor entity.

12. The method as described in claim 1, wherein the location estimation entity is the target UE, and wherein the at least two anchor-to-anchor RxTx time difference measurements are received from one of the fixed anchor entity and the moving anchor entity.

13. The method as described in claim 1, wherein the PRS in the second PRS instance group for the RSTD measurement group sent by the moving anchor entity is retained by the fixed anchor entity.

14. The method as described in claim 1, wherein the number of PRS instances in the second PRS instance group for the RSTD measurement group sent by the mobile anchor entity is limited to a time period.

15. A location estimation entity configured to determine a location of a target user equipment (UE), comprising: One memory; At least one external interface; The system includes at least one processor communicatively coupled to the memory and the at least one external interface, the at least one processor being configured to: obtain a set of Reference Signal Time Difference (RSTD) measurements for the target UE, including at least three RSTD measurements generated by the target UE at different times, wherein each RSTD measurement in the RSTD measurement set is generated using a Position Reference Signal (PRS) transmitted from a first PRS instance group by a fixed anchor entity and a corresponding PRS transmitted from a second PRS instance group by a mobile anchor entity; obtain at least two anchor-to-anchor receive-to-transmit (RxTx) time difference measurements, wherein each anchor-to-anchor RxTx time difference measurement is associated with the PRS from the first PRS instance group and the corresponding PRS from the second PRS instance group, wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the RSTD measurement set; and determine a position estimate of the target UE based on the RSTD measurement set and the at least two anchor-to-anchor RxTx time difference measurements.

16. The location estimation entity as described in claim 15, wherein each anchor-to-anchor RxTx time difference measurement is one of a measurement performed by the moving anchor entity based on the reception of a first PRS in the first PRS instance group and the transmission of a second PRS in the second PRS instance group, or by the fixed anchor entity based on the reception of a third PRS in the second PRS instance group and the transmission of a fourth PRS in the first PRS instance group.

17. The location estimation entity as described in claim 15, wherein the PRS from the first PRS instance group and the corresponding PRS from the second PRS instance group in the at least two anchor-to-anchor RxTx time difference measurements have the same RxTx timing error group identifier.

18. The location estimation entity as described in claim 15, wherein the PRS transmitted by the fixed anchor entity in the first PRS instance group associated with the at least two anchor-to-anchor RxTx time difference measurements have the same transmission timing error group identifier.

19. The location estimation entity as described in claim 15, wherein the PRS transmitted by the moving anchor entity in the second PRS instance group associated with the at least two anchor-to-anchor RxTx time difference measurements has the same transmission timing error group identifier.

20. The location estimation entity as described in claim 15, wherein the RSTD measurement group of the target UE is triggered by a location server or by the fixed anchor entity.

21. The location estimation entity as described in request item 20, wherein the RSTD measurement group for the target UE is triggered based on a location request from the target UE.

22. The location estimation entity as described in request item 20, wherein a trigger message sent to the target UE to trigger the RSTD measurement group of the target UE indicates PRS resources in the first PRS instance group and the second PRS instance group.

23. The location estimation entity as described in claim 22, wherein the PRS resources in the first PRS instance group and the second PRS instance group have the same periodicity.

24. The location estimation entity as described in request item 20, wherein a trigger message indicates the PRS resources in the first PRS instance group for the measurement of the at least two anchor-to-anchor RxTx time difference.

25. The location estimation entity as claimed in claim 15, wherein the location estimation entity is a location server, and wherein the at least one external interface includes at least one network interface, and receives the at least two anchor-to-anchor RxTx time difference measurements from one of the fixed anchor entity and the mobile anchor entity.

26. The location estimation entity as described in claim 15, wherein the location estimation entity is the target UE, and wherein the at least one external interface includes at least one radio transceiver and receives the at least two anchor-to-anchor RxTx time difference measurements from one of the fixed anchor entity and the mobile anchor entity.

27. The location estimation entity as described in claim 15, wherein the PRS in the second PRS instance group for the RSTD measurement group sent by the moving anchor entity is retained by the fixed anchor entity.

28. The location estimation entity as described in claim 15, wherein the number of PRS instances in the second PRS instance group for the RSTD measurement group sent by the moving anchor entity is limited for a time period.

29. A location estimation entity configured to determine a location of a target user equipment (UE), comprising: A component for obtaining a set of Reference Signal Time Difference (RSTD) measurements for the target UE, comprising at least three RSTD measurements generated by the target UE at different times, wherein each RSTD measurement of the RSTD measurement set is generated using a Position Reference Signal (PRS) transmitted from a first PRS instance group by a fixed anchor entity and a corresponding PRS transmitted from a second PRS instance group by a mobile anchor entity; a component for obtaining at least two anchor-to-anchor receive-to-transmit (RxTx) time difference measurements, wherein each anchor-to-anchor RxTx time difference measurement is associated with the PRS from the first PRS instance group and the corresponding PRS from the second PRS instance group, wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the RSTD measurement set; and a component for determining a position estimate of the target UE based on the RSTD measurement set and the at least two anchor-to-anchor RxTx time difference measurements.

30. A non-transitory storage medium including code stored thereon, the code being operable to configure at least one processor in a location estimation entity for determining a location of a target user equipment (UE), the code including instructions for: obtaining a set of reference signal time difference (RSTD) measurements of the target UE, including at least three RSTD measurements generated by the target UE at different times, wherein each RSTD measurement of the RSTD measurement set is generated using a positioning reference signal (PRS) from a first PRS instance group transmitted by a fixed anchor entity and a corresponding PRS from a second PRS instance group transmitted by a mobile anchor entity; At least two anchor-to-anchor receive-to-transmit (RxTx) time difference measurements are obtained, wherein each anchor-to-anchor RxTx time difference measurement is associated with the PRS from the first PRS instance group and the corresponding PRS from the second PRS instance group, wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the RSTD measurement group; and a location estimate of the target UE is determined based on the RSTD measurement group and the at least two anchor-to-anchor RxTx time difference measurements.

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