Method and apparatus for positioning estimation using a mobile anchor point

Abstract

A set of reference signal time difference (RSTD) measurements is used to determine the location of a target user equipment (UE), and the set of RSTD measurements includes at least three RSTD measurements generated by the target UE at different times. Each RSTD measurement is based on a positioning reference signal (PRS) transmitted by a stationary anchor entity and a corresponding PRS transmitted by a moving mobile anchor entity. At least two anchor-to-anchor receive transmit (RxTx) time difference measurements are generated by the anchor entities, where each anchor-to-anchor RxTx time difference measurement is associated with an RSTD measurement, and there are fewer anchor-to-anchor RxTx time difference measurements than RSTD measurements. The location estimate of the target UE is determined based on the set of RSTD measurements and the at least two anchor-to-anchor RxTx time difference measurements.

Description

[0001] Background

[0002] Field

[0003] The subject matter disclosed herein generally relates to the field of wireless communications and, more particularly, to techniques for supporting positioning.

[0004] Information

[0005] Wireless communication systems have evolved through many generations, including first-generation analog wireless telephone service (1G), second-generation (2G) digital wireless telephone service (including transitional 2.5G and 2.75G networks), third-generation (3G) high-speed data, Internet-capable wireless services, 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. Examples of known cellular systems include the cellular analog Advanced Mobile Phone System (AMPS), and digital cellular systems based on Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Global System for Mobile Communications (GSM), etc.

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

[0007] Overview

[0008] Using a set of reference signal time difference (RSTD) measurements to determine the location of a target user equipment (UE), the set of RSTD measurements including at least three RSTD measurements generated by the target UE at different times. Each RSTD measurement is based on a positioning reference signal (PRS) transmitted by a stationary anchor entity and a corresponding PRS transmitted by a moving mobile anchor entity. At least two anchor-to-anchor receive transmit (RxTx) time difference measurements are generated by the anchor entities, where each anchor-to-anchor RxTx time difference measurement is associated with an RSTD measurement, and there are fewer anchor-to-anchor RxTx time difference measurements than RSTD measurements. An estimated location of the target UE is determined based on the set of RSTD measurements and the at least two anchor-to-anchor RxTx time difference measurements.

[0009] In a specific implementation, a method of 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 for the target UE, the set of RSTD measurements including at least three RSTD measurements generated by the target UE at different times, where each RSTD measurement in the set of RSTD measurements is generated using a PRS from a first set of positioning reference signal (PRS) instances transmitted by a stationary anchor entity and a corresponding PRS from a second set of PRS instances transmitted by a moving mobile anchor entity; obtaining at least two anchor-to-anchor receive transmit (RxTx) time difference measurements, where each anchor-to-anchor RxTx time difference measurement is associated with a PRS from the first set of PRS instances and a corresponding PRS from the second set of PRS instances, and where the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements; and determining an estimated location of the target UE based on the set of RSTD measurements and the at least two anchor-to-anchor RxTx time difference measurements.

[0010] In a specific implementation, a positioning estimation entity configured to determine the positioning 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 for the target UE, the set of RSTD measurements including at least three RSTD measurements generated by the target UE at different times, wherein each RSTD measurement in the set of RSTD measurements is generated using a PRS from a first set of positioning reference signal (PRS) instances transmitted by a stationary anchor entity and a corresponding PRS from a second set of PRS instances transmitted by a mobile anchor entity; obtain at least two anchor-to-anchor receive-transmit (RxTx) time difference measurements, wherein each anchor-to-anchor RxTx time difference measurement is associated with a PRS from the first set of PRS instances and a corresponding PRS from the second set of PRS instances, and wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements; and determine a positioning estimate for the target UE based on the set of RSTD measurements and the at least two anchor-to-anchor RxTx time difference measurements.

[0011] In a specific implementation, a positioning estimation entity configured to determine the positioning of a target user equipment (UE) includes: means for obtaining a set of reference signal time difference (RSTD) measurements for the target UE, the set of RSTD measurements including at least three RSTD measurements generated by the target UE at different times, wherein each RSTD measurement in the set of RSTD measurements is generated using a PRS from a first set of positioning reference signal (PRS) instances transmitted by a stationary anchor entity and a corresponding PRS from a second set of PRS instances transmitted by a mobile anchor entity; means for obtaining at least two anchor-to-anchor receive-transmit (RxTx) time difference measurements, wherein each anchor-to-anchor RxTx time difference measurement is associated with a PRS from the first set of PRS instances and a corresponding PRS from the second set of PRS instances, and wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements; and means for determining a positioning estimate for the target UE based on the set of RSTD measurements and the at least two anchor-to-anchor RxTx time difference measurements.

[0012] In a particular implementation, a non-transitory storage medium having program code stored thereon, the program code being operative to configure at least one processor in a positioning estimation entity for determining the positioning of a target user equipment (UE), the program including instructions for performing the following operations: obtaining a set of reference signal time difference (RSTD) measurements for the target UE, the set of RSTD measurements including at least three RSTD measurements generated by the target UE at different times, wherein each RSTD measurement in the set of RSTD measurements is generated using a PRS from a first set of positioning reference signal (PRS) instances transmitted by a stationary anchor entity and a corresponding PRS from a second set of PRS instances transmitted by a mobile anchor entity; obtaining at least two anchor-to-anchor receive-transmit (RxTx) time difference measurements, wherein each anchor-to-anchor RxTx time difference measurement is associated with a PRS from the first set of PRS instances and a corresponding PRS from the second set of PRS instances, and wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements; and determining a positioning estimate for the target UE based on the set of RSTD measurements and the at least two anchor-to-anchor RxTx time difference measurements. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings are presented to assist in describing aspects of the present disclosure and are provided only for illustration and not limitation of the aspects.

[0015] Figure 1A An example wireless communication system in accordance with aspects of the present disclosure is shown.

[0016] Figure 1B Illustrated is what may be Figure 1A the architecture diagram of a base station node within.

[0017] Figure 2A and Figure 2B An example wireless network structure in accordance with aspects of the present disclosure is shown.

[0018] Figures 3A to 3C are simplified block diagrams of several sample aspects of components that may be employed and configured in a user equipment (UE), a base station, and a network entity, respectively, to support communication as taught herein.

[0019] Figures 4A to 4D is a diagram showing example frame structures and channels within these frame structures in accordance with aspects of the present disclosure.

[0020] Figure 5 is a diagram of an example positioning reference signal (PRS) resource set with different time gaps in accordance with aspects of the present disclosure.

[0021] Figure 6Shows an example of a conventional downlink (DL) time difference of arrival (TDoA) based positioning.

[0022] Figure 7 Shows an example of a conventional uplink (UL) TDoA based positioning.

[0023] Figure 8 Shows a timing diagram of TDOA measurement signals exchanged between a UE and a stationary anchor.

[0024] Figure 9 Shows a timing diagram of TDOA measurement signals exchanged between a UE and a stationary anchor with improved accuracy.

[0025] Figure 10 Shows a wireless communication system including a mobile anchor that can be used in TDOA measurements.

[0026] Figure 11 Shows a timing diagram of TDOA measurement signals exchanged between a UE and a stationary anchor and a mobile anchor with improved accuracy.

[0027] Figure 12 Shows another timing diagram of TDOA measurement signals exchanged between a UE and a stationary anchor and a mobile anchor with improved accuracy.

[0028] Figure 13 Shows positioning reference signals (PRS) transmitted by a stationary anchor and a mobile anchor to generate a set of measurements for improved accuracy.

[0029] Figure 14 Is a message flow diagram showing the messaging between a location server, a target UE, a stationary anchor, and a mobile anchor to support measurements for improved accuracy.

[0030] Figure 15 Shows a flowchart of an exemplary process for supporting operations of a positioning estimation entity to determine the location of a target UE as disclosed herein.

[0031] Detailed description

[0032] Aspects of the present disclosure are provided in the following description of various examples provided for illustrative purposes and the associated drawings. Alternative aspects can be designed without departing from the scope of the present disclosure. Additionally, well-known elements of the present disclosure will not be described in detail or will be omitted so as not to obscure the relevant details of the present disclosure.

[0033] The terms "exemplary" and / or "example" are used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" and / or "example" is not necessarily to be construed as preferred or superior to other aspects. Similarly, the term "aspects of the present disclosure" does not require that all aspects of the present disclosure include the discussed feature, advantage, or mode of operation.

[0034] Those skilled in the art will appreciate that any of a variety of different techniques and methods 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 referred to throughout the following description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof, depending in part on a particular application, in part on a desired design, in part on the corresponding technology, and so forth.

[0035] In addition, many aspects are described in terms of sequences of actions to be performed by, for example, elements of a computing device. It will be recognized that the various actions described herein can be performed by a particular circuit (e.g., an application specific integrated circuit (ASIC)), by program instructions executed by one or more processors, or by a combination of both. Additionally, the sequence of actions described herein can be considered to be fully embodied within any form of non-transitory computer-readable storage medium having stored therein a corresponding set of computer instructions that, when executed, will cause or direct a relevant processor of a device to perform the functions described herein. Accordingly, the various aspects of the present disclosure can be embodied in many different forms, all of which are contemplated to be within the scope of the claimed subject matter. Additionally, for each of the aspects described herein, a corresponding form of any such aspect can be described herein as, for example, "logic configured to perform the described action."

[0036] As used herein, unless otherwise specified, the terms "user equipment" (UE) and "base station" are not intended to be specific or otherwise limited to any particular radio access technology (RAT). In general, a UE can be any wireless communication device used by a user to communicate over a wireless communication network (e.g., a mobile phone, router, tablet computer, laptop computer, consumer asset tracking device, wearable device (e.g., smart watch, glasses, augmented reality (AR) / virtual reality (VR) headsets, etc.), vehicle (e.g., car, motorcycle, bicycle, etc.), Internet of Things (IoT) device, etc.). The UE can be mobile or can be stationary (e.g., at certain times), and can communicate with a radio access network (RAN). As used herein, the term "UE" can be interchangeably referred to as "access terminal" or "AT", "client device", "wireless device", "subscriber device", "subscriber terminal", "subscriber station", "user terminal" or "UT", "mobile device", "mobile terminal", "mobile station", or variants thereof. In general, a UE can communicate with a core network via the RAN, and through the core network, the UE can connect to external networks such as the Internet and to other UEs. Of course, other mechanisms for a UE to connect to the core network and / or the Internet are possible, such as via a wired access network, a wireless local area network (WLAN) network (e.g., based on Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards, etc.).

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

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

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

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

[0041] Figure 1AFIG. 0 shows an example wireless communication system 100 in accordance with aspects of the present disclosure. The wireless communication system 100 (which may also be referred to as a wireless wide area network (WWAN)) can include various base stations 102 (labeled "BS") and various UEs 104. The base stations 102 can include macro cell base stations (high-power cellular base stations) and / or small cell base stations (low-power cellular base stations). In one aspect, the macro cell base stations can include eNBs and / or ng-eNBs (where the wireless communication system 100 corresponds to an LTE network), or gNBs (where the wireless communication system 100 corresponds to an NR network), or a combination of both, and the small cell base stations can include femto cells, pico cells, micro cells, and the like.

[0042] The base stations 102 can together form a RAN and interface with a core network 170 (e.g., an evolved packet core (EPC) or a 5G core (5GC)) via a backhaul link 122 and interface with one or more location servers 172 (e.g., a location management function (LMF) or a secure user plane location (SUPL) location platform (SLP)) via the core network 170. The location server 172 can be part of the core network 170 or can be external to the core network 170. Among other functions, the base stations 102 can perform functions related to one or more of the following: 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, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment tracking, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations 102 can communicate with each other directly or indirectly (e.g., via the EPC / 5GC) on a backhaul link 134, which can be wired or wireless.

[0043] Base station 102 can communicate wirelessly with UE 104. Each base station in base station 102 can provide communication coverage for a corresponding geographical coverage area 110. In one aspect, one or more cells can be supported by the base stations 102 in each geographical coverage area 110. A "cell" is a logical communication entity for communicating with a base station (e.g., on a certain frequency resource, which is referred to as a carrier frequency, component carrier, carrier, frequency band, etc.), and can be associated with an identifier for distinguishing 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 that can provide access for different types of UEs (e.g., machine type communication (MTC), narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB), or other protocol types). Since a cell is supported by a specific base station, the term "cell" can, depending on the context, refer to either the logical communication entity, the base station that supports it, or both. In some cases, the term "cell" can also refer to the geographical coverage area of a base station (e.g., a sector), as long as the carrier frequency can be detected and used for communication within a certain part of the geographical coverage area 110.

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

[0045] The communication link 120 between base station 102 and UE 104 can include an uplink (also referred to as a reverse link) transmission from UE 104 to base station 102 and / or a downlink (downlink) (also referred to as a forward link) transmission from base station 102 to UE 104. The communication link 120 can also include a sidelink channel 120', which can be used to directly connect multiple UEs 104, e.g., in Figure 1Ais shown as UE 104'. The communication link 120 can use MIMO antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link 120 can operate over one or more carrier frequencies. Regarding the downlink and uplink, the allocation of carriers can be asymmetric (e.g., more or fewer carriers can be allocated to the downlink compared to the uplink).

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

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

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

[0049] Transmit beamforming is a technique used to focus RF signals in a specific direction. Traditionally, when a network node (e.g., a base station) broadcasts an RF signal, it broadcasts the signal omnidirectionally, i.e., in all directions. With transmit beamforming, the network node determines where a given target device (e.g., a UE) is located (relative to the transmitting network node) and projects a stronger downlink RF signal in that specific direction, thus providing a faster (in terms of data rate) and stronger RF signal to the receiving device(s). 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 transmitter of the one or more transmitters that broadcast the RF signal. For example, the network node can use an antenna array (referred to as a "phased array" or "antenna array") that creates an RF beam that can be "manipulated" to point in different directions without actually moving the antennas. Specifically, the RF currents from the transmitters are fed to the individual antennas with the correct phase relationships such that the radio waves from the separate antennas add together to increase the radiation in the desired direction while canceling to suppress the radiation in the undesired directions.

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

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

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

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

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

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

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

[0057] The wireless communication system 100 may also include a UE 164, which may communicate with the macro cell base station 102 via the communication link 120 and / or communicate with the mmW base station 180 via the mmW communication link 184. For example, the macro cell base station 102 may support a PCell and one or more SCell for the UE 164, and the mmW base station 180 may support one or more SCell for the UE 164.

[0058] In Figure 1A an example of, one or more space vehicle (SV) 112 of a global positioning system (GPS) (e.g., a satellite) of the Earth orbit may be used as an independent source of location information for any of the illustrated UEs (shown as a single UE 104 for simplicity in Figure 1A ). The UE 104 may include one or more dedicated GPS receivers, which are specifically designed to receive GPS signals 124 from the SV 112 to derive geographical location information. GPS generally includes a transmitter system (e.g., the SV 112), which is positioned such that a receiver (e.g., the UE 104) can determine the location of these receivers on or above the Earth at least in part based on signals received from the transmitter (e.g., the GPS signals 124). Such a transmitter typically transmits a signal marked with a repetitive pseudo-random noise (PN) code of a set number of chips. Although typically located in the SV 112, the transmitter may sometimes be located on a ground-based control station, the base station 102, and / or other UEs 104.

[0059] The use of the GPS signals 124 can be augmented by various satellite-based augmentation systems (SBAS), which may be associated with one or more global and / or regional navigation satellite systems or otherwise enabled to be used in conjunction with one or more global and / or regional navigation satellite systems. For example, the SBAS may include an enhancement system (s) that provides integrity information, differential corrections, etc., such as the Wide Area Augmentation System (WAAS), the European Geostationary Navigation Overlay Service (EGNOS), the Multi-functional Satellite Augmentation System (MSAS), the GPS-aided Geo Augmented Navigation or the GPS and Geo Augmented Navigation System (GAGAN), etc. Thus, as used herein, GPS may include any combination of one or more global and / or regional navigation satellite systems and / or augmentation systems, and the GPS signals 124 may include GPS, GPS-like, and / or other signals associated with such one or more GPS.

[0060] The wireless communication system 100 may also include one or more UEs, such as the UE 190, which are indirectly connected to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links (referred to as "sidelinks"). InFigure 1A In the example, UE 190 has a D2D P2P link 192 with a UE 104 connected to a base station 102 (e.g., UE 190 can thereby indirectly obtain cellular connectivity), and a D2D P2P link 194 with a WLAN STA 152 connected to a WLAN AP 150 (UE 190 can thereby indirectly obtain WLAN-based Internet connectivity). In one example, D2D P2P links 192 and 194 can be supported by any well-known D2D RAT, such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), and so on.

[0061] Figure 1B shows the architecture diagram of an NG-RAN node (e.g., base station 102) (e.g., as a separate entity or as part of another gNB) within the Figure 1A NG-RAN. According to a specific implementation, base station 102 can be gNB 109. For example, Figure 1B the architecture shown in Figure 1A can be applicable to any gNB 109 in

[0062] As shown in the figure, gNB 109 may include a gNB Central Unit (gNB-CU) 103, a gNB Distributed Unit (gNB-DU) 105-DU, and a gNB Remote Unit (gNB-RU) 105-RU, which may be physically co-located in the gNB 109 or may be physically separated. The gNB-CU 103 is a logical or physical node that hosts the radio resource control (RRC), service data adaptation protocol (SDAP), and packet data convergence protocol (PDCP) protocols used to support the gNB 109 on the NR Uu air interface and controls the operation of one or more gNB-DUs and / or gNB-RUs. The gNB-CU 103 terminates the F1 interface connected to the gNB-DU and, in some specific implementations, terminates the F1 interface connected to the gNB-RU. As shown in the figure, the gNB-CU 103 may communicate with the AMF via the NG interface. The gNB-CU 103 may further communicate with one or more other gNBs 109 via the Xn interface. The gNB-DU 105-DU is a logical or physical node that hosts the radio link control (RLC), media access control (MAC), and physical (PHY) protocol layers used to support the NR Uu air interface of the gNB 109, and the operation of the gNB-DU 105 is partially controlled by the gNB-CU 103. The gNB-DU terminates the F1 interface connected to the gNB-CU 103 and may terminate the lower layer split point interface Fx with the gNB-RU. The gNB-RU 105-RU may be based on lower layer function splitting and is a logical or physical node that hosts 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 the operation of the gNB-RU 105-RU 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 specific implementations, may terminate the F1 interface connected to the gNB-CU 103.

[0063] The gNB-CU 103 requests positioning measurements (e.g., E-CID) from the gNB-DU 105-DU and / or the gNB-RU 105-RU. The gNB-DU 105-DU and / or the gNB-RU 105-RU may report the measurements back to the gNB-CU 103. The gNB-DU 105-DU or the gNB-RU 105-RU may include a positioning measurement function. It should be understood that a separate measurement node is not excluded.

[0064] Additionally, as Figure 1BAs shown, gNB 109 may include a transmission point (TP) 107 and a reception point (RP) 108 combined into a transmission and reception point (TRP) 106, and the TRP 106 may be physically or logically located in gNB 109. gNB-CU 103 may be configured to communicate with TP 107 and RP 108 via, for example, the F1 interface. Thus, gNB-CU 103 controls one or more TPs 107 and RPs 108 that can be accessed from gNB-CU 103 via the F1 interface.

[0065] In some embodiments, the base station 102 (or gNB 109) may include Figure 1B a subset of the elements shown in. For example, the NG-RAN node 102 may include gNB-CU 103, but may not include one or more of gNB-DU 105-DU, gNB-RU 105-RU, RP 108, or TP 107. Alternatively, the base station 102 may include gNB-DU 105-DU and one or more of RP 108 or TP 107, but may not include gNB-RU 105-RU. Additionally, Figure 1B the elements shown in may be logically separated but physically co-located, or may be physically partially or fully separated. For example, gNB-DU 105-DU and / or one or more of gNB-RU105-RU, RP 108, or TP 107 may be physically separated from gNB-CU 103, or may be physically combined with gNB-CU 103. In the case of physical separation, the F1 or Fx interface may define signaling on the physical link or connection between the two separate elements. In some specific implementations, gNB-CU 103 may be split into a control plane part (referred to as CU-CP or gNB-CU-CP) and a user plane part (referred to as CU-UP or gNB-CU-UP). In this case, both gNB-CU-CP and gNB-CU-UP may interact with gNB-DU 105-DU and / or gNB-RU 105-RU to support NR Uu air interface signaling for the control plane and user plane, respectively. However, only gNB-CU-CP may interact with TP 107 and RP 108 to support and control location-related communication.

[0066] The protocol layering between gNB-CU 103 and TP 107 and RP 108 may be based on F1 C as defined in 3GPP TS 38.470, which uses the F1 application protocol (F1AP) at the top layer as specified in 3GPP TS 38.473. New messages supporting positioning may be directly added to F1AP, or may be introduced into a new location-specific protocol that uses F1AP for transmission.

[0067] The positioning procedures with the gNB-CU 103 may include all the location-related procedures on the NG, Xn, and NR-Uu interfaces. For example, the positioning procedures between the AMF and the base station 102 may use NGAP. The positioning procedures between the base station 102 and other NG-RAN nodes (e.g., gNB 109) may use XnAP or a protocol on top of XnAP, such as the Extended NR Positioning Protocol A (NRPPa) defined in 3GPP TS 38.455. The positioning procedures between the base station 102 and the UE 104 may use RRC and / or LPP.

[0068] The corresponding messages supporting positioning may be carried within a transparent F1AP message transfer container. For example, the transfer of NGAP location report control and NAS transmit messages may be carried in UL / DL NGAP message transfer. The transfer of location-related XnAP messages may be carried in UL / DL XnAP message transfer. The transfer of location-related RRC (LPP) messages may be carried in UL / DL RRC (LPP) message transfer.

[0069] Figure 2A An example wireless network structure 200 is shown. For example, the 5GC 210 (also referred to as the Next Generation Core (NGC)) may be functionally regarded 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, access to data networks, IP routing, etc.), which cooperate 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, and specifically connect to the user plane function 212 and the control plane function 214 respectively. In an alternative configuration, the ng-eNB 224 may also be connected to the 5GC 210 via the NG-C 215 to the control plane function 214 and the NG-U 213 to the user plane function 212. In addition, the ng-eNB 224 may communicate directly with the gNB 222 via a 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 either the ng-eNB 224 and the gNB 222. Either the gNB 222 or the ng-eNB 224 (or both) may communicate with one or more UEs 204 (e.g., any of the UEs described herein).

[0070] Another optional aspect 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 be in communication with the control plane function 214 and the user plane function 212 in the 5GC 210, respectively, to provide location assistance for the UE 204. The location server 230 may be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules distributed across multiple physical servers, etc.), or alternatively, may each correspond to a single server. The location server 230 may be configured to support one or more location services for the UE(s) 204 that may be connected to the location server 230 via the core network 5GC 210 and / or via the Internet (not shown). Additionally, the location server 230 may be integrated into a component of the core network, or alternatively may be external to the core network (e.g., a third-party server, such as an original equipment manufacturer (OEM) server or a service server).

[0071] Figure 2B Another example wireless network structure 250 is shown. For example, the 5GC 260 (also referred to as the "NGC") may be functionally considered to consist of a control plane function provided by the access and mobility management function (AMF) 264, a user plane function (UPF) 262, a session management function (SMF) 266, an SLP 268, and an LMF 270, which cooperate to form the core network (i.e., 5GC 260). The user plane interface 263 and the control plane interface 265 connect the ng-eNB 224 to the 5GC 260, specifically to the UPF 262 and the AMF 264, respectively. In an additional configuration, the gNB 222 may also be connected to the 5GC 260 via the control plane interface 265 to the AMF 264 and the user plane interface 263 to the UPF 262. Additionally, the eNB 224 may communicate directly with the gNB 222 via a backhaul connection 223 with or without direct connectivity of the gNB to the 5GC 260. In some configurations, the new RAN 220 may have only one or more gNBs 222, while other configurations include one or more of both the ng-eNB 224 and the gNB 222. The gNB 222 or the eNB 224 may communicate with the UE 204 (e.g., Figure 1A any UE depicted therein). The base stations of the new RAN 220 communicate with the AMF 264 via the N2 interface and with the UPF 262 via the N3 interface.

[0072] The functions of the AMF include registration management, connection management, reachability management, mobility management, lawful interception, transmission of session management (SM) messages between the UE 204 and the SMF 266, transparent proxy service for routing SM messages, access authentication and access authorization, transmission of short message service (SMS) messages between the UE 204 and the short message service function (SMSF) (not shown), and the security anchor function (SEAF). The AMF also interacts with the authentication server function (AUSF) (not shown) and the UE 204, and receives the intermediate key established as a result of the UE 204 authentication process. In the case of authentication based on a UMTS (Universal Mobile Telecommunications System) user identity module (USIM), the AMF retrieves the security material from the AUSF. The functions of the AMF also include security context management (SCM). The SCM receives the key from the SEAF and uses the key to derive the access network specific key. The functions of the AMF also include location service management for regulatory services, location service messaging between the UE 204 and the location management function (LMF) 270 (which may correspond to the location server 172) and between the new RAN 220 and the LMF 270, EPS bearer identifier allocation for interworking with the evolved packet system (EPS), and UE 204 mobility event notification. In addition, the AMF also supports the functions of non-3rd Generation Partnership Project (3GPP) access networks.

[0073] The functions of the UPF include: acting as an anchor for mobility within / across radio access technologies (RATs) (when applicable), acting as an external protocol data unit (PDU) session point for interconnection to data networks (not shown), providing packet routing and forwarding, packet inspection, user plane policy rule enforcement (e.g., gating, redirection, traffic control), lawful interception (user plane collection), traffic usage reporting, quality of service (QoS) handling for the user plane (e.g., UL / DL rate enforcement, reflection QoS marking in DL), UL traffic verification (service data flow (SDF) to QoS flow mapping), transmission layer packet marking in UL and DL, DL packet buffering and DL data notification triggering, and sending and forwarding of one or more "end markers" to the source RAN node.

[0074] The functions of the SMF 266 include: session management, UE Internet Protocol (IP) address allocation and management, selection and control of the user plane function, configuration of traffic control at the UPF for routing traffic to the appropriate destination, enforcement of policies and control of a part of QoS, and downlink data notification. The interface used by the SMF 266 to communicate with the AMF 264 is referred to as the N11 interface.

[0075] Another optional aspect may include an LMF 270, which may communicate with the 5GC 260 to provide location assistance for the UE 204. The LMF 270 may be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules 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, which may be connected to the LMF 270 via the core network 5GC 260 and / or via the Internet (not shown).

[0076] Figure 3A , Figure 3B and Figure 3C illustrates several example components (represented by corresponding boxes) that may be incorporated into a UE 302 (which may correspond to any UE described herein), a base station 304 (which may correspond to any base station described herein), and a network entity 306 (which may correspond to or embody any network function described herein, including the location server 230 and the LMF 270, or alternatively may be independent of Figure 2A and Figure 2B the NG-RAN 220 and / or 5GC 210 / 260 infrastructure depicted in, such as a private network) to support file transmission operations as taught herein. It will be understood that these components may be implemented in different specific implementations in different types of devices (e.g., in an ASIC, in a system-on-chip (SoC), etc.). The illustrated components may also be incorporated into other devices in the communication system. For example, other devices in the system may include components similar to those described as providing similar functions. Additionally, a given device may include one or more of these components. For example, a device may include multiple transceiver components that enable the device to operate on multiple carriers and / or communicate via different technologies.

[0077] UE 302 and base station 304 each include at least one wireless wide area network (WWAN) transceiver 310 and 350, respectively, to provide means (e.g., means for transmitting, means for receiving, means for measuring, means for tuning, means for suppressing transmission, etc.) for communicating via one or more wireless communication networks (not shown) (such as an NR network, an LTE network, a GSM network, etc.). WWAN transceivers 310 and 350 may be respectively connected to one or more antennas 316 and 356 to communicate with other network nodes (such as other UEs, access points, base stations (e.g., eNB, gNB), etc.) via at least one specified RAT (e.g., NR, LTE, GSM, etc.) over an interested wireless communication medium (e.g., a certain set of time / frequency resources in a specific spectrum). WWAN transceivers 310 and 350 may be respectively configured in various ways according to the specified RAT for transmitting and encoding signals 318 and 358 (e.g., messages, indications, information, etc.), and vice versa for receiving and decoding signals 318 and 358 (e.g., messages, indications, information, pilots, etc.). Specifically, WWAN transceivers 310 and 350 respectively include: one or more transmitters 314 and 354 respectively for transmitting and encoding signals 318 and 358, and one or more receivers 312 and 352 respectively for receiving and decoding signals 318 and 358.

[0078] At least in some cases, UE 302 and base station 304 each further include at least one short-range wireless transceiver 320 and 360, respectively. The short-range wireless transceivers 320 and 360 may be respectively connected to one or more antennas 326 and 366 and provide means for communicating over an interested wireless communication medium via at least one specified RAT (e.g., WiFi, LTE-D, Z- Devices for communicating with other network nodes (such as other UEs, access points, base stations, etc.) using PC5, dedicated short-range communication (DSRC), wireless access for vehicle environments (WAVE), near-field communication (NFC), etc. (e.g., devices for transmitting, receiving, measuring, tuning, blocking transmission, etc.). The short-range wireless transceivers 320 and 360 can be configured in various ways to transmit and encode signals 328 and 368 (e.g., messages, indications, information, etc.) respectively according to the specified RAT, and vice versa to receive and decode signals 328 and 368 (e.g., messages, indications, information, pilots, etc.). Specifically, the short-range wireless transceivers 320 and 360 each 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 a specific example, the short-range wireless transceivers 320 and 360 can be WiFi transceivers, transceivers, and / or Z- transceivers, NFC transceivers, or vehicle-to-vehicle (V2V) and / or vehicle-to-everything (V2X) transceivers.

[0079] The transceiver circuitry including at least one transmitter and at least one receiver may include an integrated device (e.g., a transmitter circuit and a receiver circuit implemented as a single communication device) in some specific implementations, may include separate transmitter devices and separate receiver devices in some specific implementations, or may be implemented in other ways in other specific implementations. In one aspect, the transmitter may include or be coupled to a plurality of antennas such as an antenna array (e.g., antennas 316, 326, 356, 366), which allows the corresponding device to perform transmit "beamforming" as described herein. Similarly, the receiver may include or be coupled to a plurality of antennas such as an antenna array (e.g., antennas 316, 326, 356, 366), which allows the corresponding device to perform receive beamforming as described herein. In one aspect, the transmitter and the receiver may share the same plurality of antennas (e.g., antennas 316, 326, 356, 366) such that the corresponding device can only receive or transmit at a given time, not both simultaneously. The wireless communication devices of the UE 302 and / or the base station 304 (e.g., one or both of the transceivers 310 and 320 and / or one or both of the transceivers 350 and 360) may also include a network listening module (NLM) for performing various measurements, etc.

[0080] In at least some cases, the UE 302 and the base station 304 also include satellite positioning system (SPS) receivers 330 and 370. The SPS receivers 330 and 370 can be respectively connected to one or more antennas 336 and 376, and can respectively provide means 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), etc. The SPS receivers 330 and 370 can respectively include any suitable hardware and / or software for receiving and processing the SPS signals 338 and 378. The SPS receivers 330 and 370 request information and operations from other systems when appropriate, and perform the necessary calculations to determine the positions of the UE 302 and the base station 304 using the measurements obtained by any suitable SPS algorithm.

[0081] The base station 304 and the network entity 306 each respectively include at least one network interface 380 and 390, thereby providing means for communicating with other network entities (e.g., means for transmitting, means for receiving, etc.). For example, the network interfaces 380 and 390 (e.g., one or more network access ports) can be configured to communicate with one or more network entities via a wired-based or wireless backhaul connection. In some aspects, the network interfaces 380 and 390 can be implemented as transceivers configured to support wired-based or wireless signal communication. This communication can involve, for example, sending and receiving: messages, parameters, and / or other types of information.

[0082] In one aspect, at least one WWAN transceiver 310 and / or at least one short-range wireless transceiver 320 can form the (wireless) communication interface of the 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 can form the (wireless) communication interface of the base station 304. Likewise, at least one network interface 390 can form the (wireless) communication interface of the network entity 306. Various wireless transceivers (e.g., transceivers 310, 320, 350, 360, etc.) and wired transceivers (e.g., network interfaces 380 and 390) can generally be characterized as at least one transceiver, or alternatively, as at least one communication interface. Thus, whether a particular transceiver or communication interface involves a wired or wireless transceiver or communication interface can be inferred from the type of communication being performed (e.g., backhaul communication between network devices or servers typically involves signaling via at least one wired transceiver).

[0083] UE 302, base station 304, and network entity 306 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. Accordingly, processors 332, 384, and 394 can provide means for processing, such as means for determining, means for calculating, means for receiving, means for transmitting, means for indicating, etc. In one aspect, processors 332, 384, and 394 can 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 devices or processing circuitry, or various combinations thereof.

[0084] UE 302, base station 304, and network entity 306 include memory circuitry that implements memory components 340, 386, and 396 (e.g., each including a memory device) for maintaining information (e.g., information indicating reserved resources, thresholds, parameters, etc.). Memory components 340, 386, and 396 can thus provide means for storing, means for retrieving, means for maintaining, etc. In some cases, UE 302, base station 304, and network entity 306 can each include PRS modules 342, 388, and 398. PRS modules 342, 388, and 398 can be hardware circuits that are part of or coupled to processors 332, 384, and 394, respectively, and that, when executed, cause UE 302, base station 304, and network entity 306 to perform the functions described herein. In other aspects, PRS modules 342, 388, and 398 can 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 can be memory modules stored in memory components 340, 386, and 396, respectively, that, 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 The possible locations of PRS module 342 are shown, which can be, for example, part of at least one WWAN transceiver 310, memory component 340, at least one processor 332, or any combination thereof, or can be an independent component. Figure 3BShows a possible location of the PRS module 388, which can be, for example, part of at least one WWAN transceiver 350, a memory component 386, at least one processor 384, or any combination thereof, or can be an independent component. Figure 3C Shows a possible location of the PRS module 398, which can be, for example, part of at least one network interface 390, a memory component 396, at least one processor 394, or any combination thereof, or can be an independent component.

[0085] The UE 302 can include one or more sensors 344 coupled to at least one processor 332 to provide means for sensing or detecting movement and / or orientation information that is 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 an SPS receiver 330. As an example, the sensor 344 can include an accelerometer (e.g., a microelectromechanical systems (MEMS) device), a gyroscope, a geomagnetic sensor (e.g., a compass), an altimeter (e.g., a barometric altimeter), and / or any other type of motion detection sensor. Additionally, the sensor 344 can include multiple different types of devices and combine their outputs to provide motion information. For example, the sensor 344 can use a combination of a multi-axis accelerometer and an orientation sensor to provide the ability to calculate positioning in a two-dimensional (2D) and / or three-dimensional (3D) coordinate system.

[0086] Additionally, the UE 302 includes a user interface 346 that provides means for providing an indication to the user (e.g., an audible and / or visual indication) and / or for receiving user input (e.g., when the user actuates a sensing device such as a keypad, a touch screen, a microphone, etc.). Although not shown, the base station 304 and the network entity 306 can also include a user interface.

[0087] Referring more specifically to at least one processor 384, in the downlink, IP packets from the network entity 306 can be provided to at least one processor 384. The at least one processor 384 can implement functions for the RRC layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, and Medium Access Control (MAC) layer. The at least one processor 384 can provide: RRC layer functions associated with the broadcast of 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), inter-RAT mobility, and measurement configuration for UE measurement reporting; PDCP layer functions associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functions associated with the transfer of upper layer PDUs, error correction via Automatic Repeat reQuest (ARQ), concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and re-ordering of RLC data PDUs; MAC layer functions associated with the mapping between logical channels and transport channels, scheduling information reporting, error correction, priority handling, and logical channel prioritization.

[0088] The transmitter 354 and the 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 transport channel, forward error correction (FEC) encoding / decoding of the transport channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The transmitter 354 processes the mapping to the signal constellation based on various modulation schemes (e.g., Binary Phase Shift Keying (BPSK), Quadrature Phase Shift Keying (QPSK), M-Phase Shift Keying (M-PSK), M-Quadrature Amplitude Modulation (M-QAM)). The coded and modulated symbols can then be divided into parallel streams. Each stream can then be mapped to Orthogonal Frequency Division Multiplexing (OFDM) subcarriers, multiplexed with reference signals (e.g., pilots) in the time domain and / or frequency domain, and then combined together using the Inverse Fast Fourier Transform (IFFT) to generate a physical channel carrying a time-domain OFDM symbol stream. The OFDM symbol stream is spatially pre-coded to generate multiple spatial streams. Channel estimates from the channel estimator can be used to determine the coding and modulation schemes and for spatial processing. The channel estimates can be derived based on reference signals transmitted by the UE 302 and / or channel status feedback. Each spatial stream can then be provided to one or more different antennas 356. The transmitter 354 modulates the RF carrier with the corresponding spatial stream for transmission.

[0089] At the UE 302, the receiver 312 receives signals via its respective antenna(s) 316. The receiver 312 recovers the information modulated onto the RF carrier and provides this information to at least one processor 332. The transmitter 314 and the receiver 312 implement layer 1 functions associated with various signal processing functions. The receiver 312 may perform spatial processing on the information to recover any spatial streams destined for the UE 302. If multiple spatial streams are destined for the UE 302, they may be combined by the receiver 312 into a single OFDM symbol stream. The receiver 312 then uses the fast Fourier transform (FFT) to transform the OFDM symbol stream from the time domain to the frequency domain. The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols and reference signals on each subcarrier are recovered and demodulated by determining the signal constellation points most likely transmitted by the base station 304. These soft decisions may be based on channel estimates computed by the channel estimator. The soft decisions are then decoded and deinterleaved to recover the data and control signals initially transmitted by the base station 304 on the physical channel. These data and control signals are subsequently provided to at least one processor 332 that implements layer 3 (L3) and layer 2 (L2) functions.

[0090] In the uplink, at least one processor 332 provides demultiplexing between the transport channel and the logical channel, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the core network. At least one processor 332 is also responsible for error detection.

[0091] Similar to the functionality described in connection with downlink transmissions by the base station 304, at least one processor 332 provides: RRC layer functionality associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functionality associated with header compression / decompression and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction via ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with the mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction via hybrid automatic repeat request (HARQ), priority handling, and logical channel prioritization.

[0092] Channel estimates derived by a channel estimator from reference signals or feedback transmitted by the base station 304 can be used by the transmitter 314 to select an appropriate decoding and modulation scheme and assist in spatial processing. The spatial streams generated by the transmitter 314 can be provided to different antennas 316. The transmitter 314 can modulate an RF carrier with the corresponding spatial streams for transmission.

[0093] Uplink transmissions are processed at the base station 304 in a manner similar to that described in connection with the receiver functionality at the UE 302. The receiver 352 receives signals via its corresponding antennas 356. The receiver 352 recovers the information modulated onto the RF carrier and provides the information to at least one processor 384.

[0094] In the uplink, at least one processor 384 provides demultiplexing between the transmit channel and the logical channel, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 302. The 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.

[0095] For convenience, the UE 302, the base station 304, and / or the network entity 306 are shown in Figures 3A to 3C as including various components that can be configured according to the various examples described herein. However, it will be understood that the shown components can have different functions in different designs. In particular, while the operation of a computing device generally requires some components (e.g., memory and processor components), Figures 3A to 3C the various other components in Figure 3A are optional and can vary according to the specific implementation. For example, in the case of Figure 3B , a particular implementation of the UE 302 can omit the WWAN transceiver(s) 310 (e.g., a wearable device or a tablet calculator or a PC or a laptop device can have Wi-Fi and / or Bluetooth functionality without cellular functionality), or can omit the short-range wireless transceiver(s) 320 (e.g., only cellular, etc.), or can omit the SPS receiver 330, or can omit the sensor(s) 344, etc. In another example, in the case of

[0096] The various components of the UE 302, base station 304, and network entity 306 may communicate with each other on data buses 334, 382, and 392, respectively. In one aspect, the data buses 334, 382, and 392 may form or be part of the communication interfaces of the UE 302, base station 304, and network entity 306, respectively. For example, in cases where different logical entities are included in the same device (e.g., a gNB and a location server function incorporated into the same base station 304), the data buses 334, 382, and 392 may provide communication between them.

[0097] Figures 3A to 3C The various components of can be implemented in various ways. In some specific implementations, Figures 3A to 3C the components of

[0097] can be implemented in one or more circuits, such as, by way of example, one or more processors and / or one or more ASICs (which may include one or more processors). Here, each circuit may use and / or incorporate at least one memory component for storing information or executable code used by the circuit to provide the function. For example, some or all of the functions represented by blocks 310 to 346 may be implemented by the processor(s) and memory components of the 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 may be implemented by the processor(s) and memory components of the base station 304 (e.g., by executing appropriate code and / or by appropriate configuration of the processor components). Additionally, some or all of the functions represented by blocks 390 to 398 may be implemented by the processor(s) and memory components of the 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", "performed by the base station", "performed by the network entity", etc. However, as will be understood, such operations, actions, and / or functions may actually be performed by specific components or combinations of components of the 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.

[0098] In some designs, the network entity 306 may be implemented as a core network component. In other designs, the network entity 306 may operate differently from a network operator or a cellular network infrastructure (e.g., NG RAN 220 and / or 5GC 210 / 260). For example, the network entity 306 may be a component of a private network that may be configured to communicate with the UE 302 via the base station 304 or independently of the base station 304 (e.g., via a non-cellular communication link such as WiFi).

[0099] Various frame structures can be used to support downlink and uplink transmissions between network nodes (e.g., base stations and UEs). Figure 4A FIG. 400 is an illustration showing an example of a downlink frame structure according to aspects of the present disclosure. Figure 4B FIG. 430 is an illustration showing an example of channels within a downlink frame structure according to aspects of the present disclosure. Figure 4C FIG. 450 is an illustration showing an example of an uplink frame structure according to aspects of the present disclosure. Figure 4D FIG. 480 is an illustration showing an example of channels within an uplink frame structure according to aspects of the present disclosure. Other wireless communication technologies may have different frame structures and / or different channels.

[0100] LTE, and in some cases NR, utilize OFDM on the downlink and single - carrier frequency - division multiplexing (SC - FDM) on the uplink. However, different from LTE, NR also has the option of using OFDM on the uplink. OFDM and SC - FDM divide the system bandwidth into multiple (K) orthogonal sub - carriers, which are also often referred to as frequency tones, frequency slots, etc. Each sub - carrier can be modulated with data. Generally, modulation symbols are transmitted using OFDM in the frequency domain and SC - FDM in the time domain. The spacing between adjacent sub - carriers can be fixed, and the total number (K) of sub - carriers can depend on the system bandwidth. For example, the sub - carrier spacing can be 15 kilohertz (kHz), and the minimum resource allocation (resource block) can be 12 sub - carriers (or 180 kHz). Thus, for system bandwidths of 1.25 megahertz (MHz), 2.5 MHz, 5 MHz, 10 MHz, or 20 MHz, the nominal FFT sizes can be equal to 128, 256, 512, 1024, or 2048 respectively. The system bandwidth can also be divided into multiple sub - bands. For example, a sub - band can cover 1.08 MHz (i.e., 6 resource blocks), and for system bandwidths of 1.25 MHz, 2.5 MHz, 5 MHz, 10 MHz, or 20 MHz, there can be 1, 2, 4, 8, or 16 sub - bands respectively.

[0101] LTE supports single parameter design (subcarrier spacing (SCS), symbol length, etc.). In contrast, NR can support multiple parameter designs (μ). For example, subcarrier spacings of 15 kHz (μ = 0), 30 kHz (μ = 1), 60 kHz (μ = 2), 120 kHz (μ = 3), and 240 kHz (μ = 4) or larger may be available. In each subcarrier spacing, there are 14 symbols per time slot. For 15 kHz SCS (μ = 0), there is one time slot per subframe, 10 time slots per frame, the time slot duration is 1 millisecond (ms), the symbol duration is 66.7 microseconds (μs), and the maximum nominal system bandwidth (in MHz) with a 4K FFT size is 50. For 30 kHz SCS (μ = 1), there are two time slots per subframe, 20 time slots per frame, the time slot duration is 0.5 ms, the symbol duration is 33.3 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFT size is 100. For 60 kHz SCS (μ = 2), there are four time slots per subframe, 40 time slots per frame, the time slot duration is 0.25 ms, the symbol duration is 16.7 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFT size is 200. For 120 kHz SCS (μ = 3), there are eight time slots per subframe, 80 time slots per frame, the time slot duration is 0.125 ms, the symbol duration is 8.33 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFT size is 400. For 240 kHz SCS (μ = 4), there are 16 time slots per subframe, 160 time slots per frame, the time slot duration is 0.0625 ms, the symbol duration is 4.17 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFT size is 800.

[0102] In Figures 4A to 4D the example of, the parameter design of 15 kHz is used. Thus, in the time domain, a 10 ms frame is divided into 10 equal-sized subframes, each subframe being 1 ms, and each subframe includes one time slot. In Figures 4A to 4D it, time is represented horizontally (on the X-axis), where time increases from left to right, while frequency is represented vertically (on the Y-axis), where frequency increases (or decreases) from bottom to top.

[0103] A resource grid can be used to represent a time slot, and each time slot includes one or more time-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 one symbol length in the time domain and one subcarrier in the frequency domain. In Figures 4A to 4DIn the parameter design, for the normal cyclic prefix, an RB can include 12 consecutive subcarriers in the frequency domain and 7 consecutive symbols in the time domain, for a total of 84 REs. For the extended cyclic prefix, an RB can include 12 consecutive subcarriers in the frequency domain and 6 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.

[0104] Some REs carry downlink reference (pilot) signals (DL-RS). The DL-RS can 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), and so on. Figure 4A An example location of an RE carrying PRS (labeled "R") is shown.

[0105] The set of resource elements (REs) used for the transmission of PRS is referred to as the "PRS resource". The set of resource elements can span multiple PRBs in the frequency domain and "N" (such as 1 or more) consecutive symbols within a time slot in the time domain. In a given OFDM symbol in the time domain, the PRS resource occupies consecutive PRBs in the frequency domain.

[0106] The transmission of the PRS resource within a given PRB has a specific comb size (also referred to as "comb density"). The comb size "N" represents the subcarrier spacing (or frequency / tone spacing) 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 of the PRB. For example, for a comb-4, for each symbol of the PRS resource configuration, the REs corresponding to every fourth subcarrier (such as subcarriers 0, 4, 8) are used to transmit the PRS of the PRS resource. Currently, DL-PRS is supported for comb sizes of comb-2, comb-4, comb-6, and comb-12. Figure 4A An example PRS resource configuration for a comb-6 (which spans 6 symbols) is shown. That is, the location of the shaded REs (labeled "R") indicates the PRS resource configuration of the comb-6.

[0107] Currently, DL-PRS resources use a full-frequency domain interleaving pattern that can span 2, 4, 6, or 12 consecutive symbols within a time slot. The DL-PRS resources can be configured in any downlink or flexible (FL) symbol configured by the higher layers in the 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 per-symbol frequency offsets for comb sizes 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: {0,1,0,1,0,1,0,1,0,1,0,1,0,1}; 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}; and 12-symbol comb - 12: {0,6,3,9,1,7,4,10,2,8,5,11}.

[0108] A "PRS resource set" is a set of PRS resources used to transmit PRS signals, where each PRS resource has a PRS resource identifier (ID). Additionally, the 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 is associated with a specific TRP (identified by the TRP ID). Additionally, the PRS resources in a PRS resource set have the same periodicity, shared silent mode configuration, and the same repetition factor (such as "PRS-ResourceRepetitionFactor") across time slots. The periodicity is the time from the first repetition of the first PRS resource of the first PRS instance to the same first repetition of the same first PRS resource of the next PRS instance. The periodicity can have a length selected from: 2^μ*{4,5,8,10,16,20,32,40,64,80,160,320,640,1280,2560,5120,10240} time slots, where μ = 0,1,2,3. The repetition factor can have a length selected from {1,2,4,6,8,16,32} time slots.

[0109] The PRS resource ID in a PRS resource set is associated with a single beam (or beam ID) transmitted from a single TRP (where a 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 thus, a "PRS resource" (or simply "resource") can also be referred to as a "beam". Note that this does not imply anything about whether the UE knows the TRP and beam transmitting the PRS.

[0110] A "PRS instance" or "PRS occasion" is an instance of a periodically repeating time window (such as a group of one or more consecutive time slots) in which a PRS is expected to be transmitted. A PRS occasion may also be referred to as a "PRS positioning occasion", "PRS positioning instance", "positioning occasion", "positioning instance", "positioning repetition", or simply as an "occasion", "instance", or "repetition".

[0111] A "positioning frequency layer" (also abbreviated as "frequency layer") is a set of one or more PRS resource sets that have the same values for certain parameters across one or more TRPs. Specifically, the set of PRS resource sets has the same subcarrier spacing and cyclic prefix (CP) type (meaning that all parameter designs supported for PDSCH are also supported for PRS), the same point A, the same value for the downlink PRS bandwidth, the same starting PRB (and center frequency), and the same comb size. The point A parameter takes the value of the parameter "ARFCN-ValueNR" (where "ARFCN" stands for "absolute radio frequency channel number") and is an identifier / code that specifies a pair of physical radio channels to be used for transmission and reception. The downlink PRS bandwidth can have a granularity of 4 PRB, and the minimum value is 24 PRB while the maximum value is 272 PRB. Currently, up to 4 frequency layers are defined, and up to 2 PRS resource sets can be configured per TRP per frequency layer.

[0112] The concept of a frequency layer is somewhat similar to the concepts of a component carrier and a bandwidth part (BWP), but the difference is that component carriers and BWPs are used by a base station (or a macro cell base station and a small cell base station) to transmit data channels, while frequency layers are used by several (often three or more) base stations to transmit PRSs. A UE can indicate the number of frequency layers that the UE can support when the UE sends its positioning capabilities to the network (such as during an LTE positioning protocol (LPP) session). For example, the UE can indicate whether the UE can support one or four positioning frequency layers.

[0113] Figure 4BShows an example of various channels within the downlink time slots of a radio frame. In NR, the channel bandwidth or system bandwidth is divided into multiple BWPs. A BWP is a set of contiguous PRBs selected from a contiguous subset of common RBs designed for a given carrier with given parameters. Generally, a maximum of 4 BWPs can be specified for both the downlink and the uplink. That is, a UE can be configured to have at most 4 BWPs on the downlink and at most 4 BWPs on the uplink. At a given time, only one BWP (either uplink or downlink) can be active, which means that the UE can only receive or transmit on one BWP at a time. On 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.

[0114] Reference Figure 4B , the primary synchronization signal (PSS) is used by the UE to determine subframe / symbol timing and the physical layer identity. The secondary synchronization signal (SSS) is used by the UE to determine the physical layer cell identity group number and the radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine the PCI. Based on the PCI, the UE can determine the position of the aforementioned DL-RS. The physical broadcast channel (PBCH) carrying the MIB can be logically grouped with the PSS and SSS to form the SSB (also known as SS / PBCH). The MIB provides the number of RBs in the downlink system bandwidth and the system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information (such as system information blocks (SIBs)) not transmitted through the PBCH, and paging messages.

[0115] 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 may 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 the PDCCH / DCI is called the control resource set (CORESET) in NR. In NR, the PDCCH is restricted to a single CORESET and is transmitted together with its own DMRS. This enables UE-specific beamforming for the PDCCH.

[0116] In Figure 4BIn the example, there is one CORESET for each BWP, and this CORESET spans three symbols in the time domain (although it can be only one symbol or two symbols). Different from the LTE control channel that occupies the entire system bandwidth, in NR, the PDCCH channel is localized in a specific region in the frequency domain (i.e., the CORESET). Thus, Figure 4B The frequency components of the PDCCH shown in Figure 4B are shown in the frequency domain as less than a single BWP. Note that although the illustrated CORESET is continuous in the frequency domain, the CORESET does not need to be continuous. Additionally, the CORESET can span less than three symbols in the time domain.

[0117] The DCI within the PDCCH carries information about uplink resource allocation (persistent and non-persistent) and a description of the downlink data transmitted to the UE (referred to as uplink grant and downlink grant, respectively). More specifically, the DCI indicates the resources scheduled for the downlink data channel (e.g., PDSCH) and the uplink data channel (e.g., PUSCH). Multiple (e.g., up to 8) DCIs can be configured in the PDCCH, and these DCIs can have one of multiple formats. For example, there are different DCI formats for uplink scheduling, downlink scheduling, uplink transmit power control (TPC), etc. The PDCCH can be transmitted by 1, 2, 4, 8, or 16 CCEs to accommodate different DCI payload sizes or decoding rates.

[0118] As Figure 4C shown in Figure 4C , some of the REs (labeled "R") carry DMRS for channel estimation at the receiver (e.g., the base station, another UE, etc.). The UE can additionally transmit SRS, for example, in the last symbol of a time slot. The SRS can have a comb structure, and the UE can transmit the SRS on one of the combs. In Figure 4C the example of Figure 4C , the shown SRS is a comb-2 on one symbol. The SRS can be used by the base station to obtain the channel state information (CSI) of each UE. The CSI describes how the RF signal propagates from the UE to the base station and represents the combined effect of scattering, fading, and power attenuation with distance. The system uses the SRS for resource scheduling, link adaptation, massive MIMO, beam management, etc.

[0119] Currently, SRS resources with comb sizes of Comb-2, Comb-4, or Comb-8 can span 1, 2, 4, 8, or 12 consecutive symbols within a time slot. The following are the per-symbol frequency offsets for currently supported SRS comb patterns. 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}.

[0120] The set of resource elements used for SRS transmission is referred to as an "SRS resource" and can be identified by the parameter "SRS-ResourceId (SRS resource ID)". The set of resource elements can span multiple PRBs in the frequency domain and N (e.g., one or more) consecutive symbols within a time slot. In a given OFDM symbol, the SRS resource occupies consecutive PRBs. An "SRS resource set" is a group of SRS resources used for SRS signal transmission and is identified by an SRS resource set ID ("SRS-ResourceSetId").

[0121] Generally, a UE transmits SRS so that the receiving base station (serving base station or neighboring base station) can measure the channel quality between the UE and the base station. However, 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), uplink angle of arrival (UL-AoA), etc. As used herein, the term "SRS" can refer to SRS configured for channel quality measurement or SRS configured for positioning purposes. When it is necessary to distinguish between the two types of SRS, the former can be referred to herein as "SRS-for-communication" and / or the latter can be referred to as "SRS-for-positioning".

[0122] A number of enhancements to the previously defined SRS have been proposed for "SRS for positioning" (also known as "UL-PRS"), such as new interleaving patterns within the SRS resource (in addition to single-symbol / comb-2), new comb types of the SRS, new sequences of the SRS, a larger number of SRS resource sets per component carrier, and a larger number of SRS resources per component carrier. Additionally, the parameters "SpatialRelationInfo" and "PathLossReference" are to be configured based on the downlink reference signals or SSBs from neighboring TRPs. Further still, an SRS resource can be transmitted outside the active BWP, and an SRS resource can span multiple component carriers. Also, the SRS can be configured in the RRC connected state and transmitted only within the active BWP. Moreover, there may be no frequency hopping, no repetition factor, a single antenna port, and a new length of the SRS (e.g., 8 and 12 symbols). There may also be open-loop power control and no closed-loop power control, and comb-8 (i.e., SRS transmitted on every eighth subcarrier in the same symbol) can be used. Finally, the UE can transmit from multiple SRS resources using the same transmit beam for UL-AoA. All of these are features outside the current SRS framework, which is configured via RRC higher layer signaling (and potentially triggered or activated via MAC control element (CE) or DCI).

[0123] Figure 4D An example of various channels within an uplink time slot of a frame in accordance with aspects of the present disclosure is shown. The random access channel (RACH) (also known as the physical random access channel (PRACH)) can be within one or more time slots in the frame based on the PRACH configuration. The PRACH can include 6 consecutive RB pairs within a time slot. The PRACH allows the UE to perform initial system access and achieve 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 a scheduling request, CSI report, 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 additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and / or UCI.

[0124] Note that the terms "positioning reference signal" and "PRS" generally refer to specific reference signals for positioning in NR and LTE systems. However, as used herein, the terms "positioning 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. Additionally, the terms "positioning reference signal" and "PRS" can refer to downlink or uplink positioning reference signals, unless otherwise indicated by the context. If further differentiation of the type of PRS is needed, the downlink positioning reference signal can be referred to as "DL-PRS", and the uplink positioning reference signal (e.g., SRS, PTRS for positioning) can be referred to as "UL-PRS". Additionally, for signals that can be transmitted in both the uplink and downlink (e.g., DMRS, PTRS), these signals can be prefixed with "UL" or "DL" to distinguish the direction. For example, "UL-DMRS" can be distinguished from "DL-DMRS".

[0125] Figure 5 is a diagram of example PRS resource sets with different time gaps according to aspects of the present disclosure. In Figure 5 the example, time is represented horizontally and frequency is represented vertically. Each box represents a time slot in the time domain and a certain bandwidth in the frequency domain.

[0126] Figure 5 Two DL-PRS resource set configurations are shown, namely a first DL-PRS resource set configuration 510 and a second DL-PRS resource set configuration 550. Each of the 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. The repetition factor of four means that each of the four PRS resources is repeated four times (i.e., transmitted four times) in the DL-PRS resource set. That is, each of the four PRS resources within the DL-PRS resource set has four repetitions.

[0127] The DL-PRS resource set configuration 510 has a time gap of one time slot, which means that each repetition of a PRS resource (e.g., "Resource 1") starts on the first time slot after the previous repetition of that PRS resource. Thus, as shown in the DL-PRS resource set configuration 510, the four repetitions of each of the four PRS resources are grouped together. Specifically, 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 next four time slots (i.e., time slots n + 4 to n + 7), the four repetitions of PRS resource "Resource 3" occupy the next 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).

[0128] In contrast, the DL-PRS resource set configuration 550 has a time gap of four time slots, which means that each repetition of a PRS resource (e.g., "Resource 2") starts on the fourth time slot after the previous repetition of that PRS resource. Thus, as shown in the DL-PRS resource set configuration 550, the four repetitions of each of the four PRS resources are scheduled on every fourth time slot. For example, the four repetitions of 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).

[0129] Note that, as shown in Figure 5 the time duration spanned by one DL-PRS resource set containing repeated DL-PRS resources should not exceed the PRS periodicity. Also, the UE receive beam sweeping for receiving / measuring the DL-PRS resource set is not specified and depends on the UE implementation.

[0130] NR supports multiple cellular network-based positioning techniques, including downlink-based positioning methods, uplink-based positioning methods, and downlink- and uplink-based positioning methods. Downlink-based positioning methods 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 the OTDOA or DL-TDOA positioning procedures, the UE measures the difference in the time of arrival (ToA) of reference signals (e.g., positioning reference signals (PRS)) received from paired base stations (referred to as reference signal time difference (RSTD) or time difference of arrival (TDOA) measurements), and reports these differences to the positioning entity. More specifically, the UE receives the identifiers (IDs) of the reference base station (e.g., serving base station) and multiple non-reference base stations in the assistance 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 involved base stations and the RSTD measurements, the positioning entity can estimate the location of the UE.

[0131] For DL-AoD positioning, the positioning entity uses beam reports of received signal strength measurements of multiple downlink transmission beams from the UE to determine the angle(s) between the UE and the transmitting base station(s). The positioning entity can then estimate the location of the UE based on the determined angle(s) and the known location(s) of the transmitting base station(s).

[0132] 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 UL-TDOA 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 reception beams. The positioning entity uses the signal strength measurements and the angle(s) of the reception beam(s) to determine the angle(s) between the UE and the base station(s). Based on the determined angle(s) and the known location(s) of the base station(s), the positioning entity can then estimate the location of the UE.

[0133] Downlink- and uplink-based positioning methods include: Enhanced Cell ID (E-CID) positioning and Multi-Round Trip Time (RTT) positioning (also known as "Multi-Cell RTT"). In the RTT procedure, the initiator (base station or UE) transmits an RTT measurement signal (e.g., PRS or SRS) to the responder (UE or base station), and the responder transmits 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 Received Transmission (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 Transmission-to-Receive (Tx-Rx) time difference). The propagation time between the initiator and the responder (also known as "time of flight") can be calculated based on 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 so that the position of the UE can be determined based on the known positions of the respective base stations (e.g., using multilateration). The RTT and multi-RTT methods can be combined with other positioning techniques (such as UL-AoA and DL-AoD) to improve position accuracy.

[0134] 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 timing, and signal strength of the detected neighboring base stations. Subsequently, the position of the UE is estimated based on this information and the known positions of the base station(s).

[0135] To assist in the positioning operation, a location server (e.g., location server 230, LMF 270, SLP 272) may provide the UE with assistance data. For example, the assistance data may include: the identifier of the base station (or the cell / TRP of the base station) from which to measure the reference signal, reference signal configuration parameters (e.g., the number of consecutive positioning subframes, the periodicity of the positioning subframes, the silence sequence, the hopping sequence, the reference signal identifier, the reference signal bandwidth, etc.) and / or other parameters applicable to a specific positioning method. Alternatively, the assistance data may directly originate from the base station itself (e.g., in periodically broadcast overhead messages, etc.). In some cases, the UE itself may be able to detect neighboring network nodes without using assistance data.

[0136] In the case of OTDOA or DL-TDOA positioning procedures, the assistance data may further include an expected RSTD value and an associated uncertainty, or a search window around the expected RSTD. In some cases, the value range of the expected RSTD may be + / - 500 microseconds (μs). In some cases, when any resource used for positioning measurements is in FR1, the value range of the uncertainty of the expected RSTD may be + / - 32 μs. In other cases, when all resources used for positioning measurements are in FR2, the value range of the uncertainty of the expected RSTD may be + / - 8 μs.

[0137] A location estimate may be referred to by other names, such as positioning estimate, location, positioning, position lock, lock, etc. A location estimate may be geodetic and include coordinates (e.g., latitude, longitude, and possibly altitude), or it may be civic and include a street address, postal address, or some other verbal location description. A location estimate may be further defined relative to some other known location or in absolute terms (e.g., using latitude, longitude, and possibly altitude). A location estimate may include an expected error or uncertainty (e.g., by including the area or volume within which the location is expected to be included with a certain specified or default confidence).

[0138] Figure 6 An exemplary wireless communication system 600 is shown that illustrates the implementation of positioning using the downlink time difference of arrival (TDOA) technique. In Figure 6 the example, 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 third-party application, etc.) in calculating an estimate of its location. UE 104 may use RF signals and standardized protocols for modulating RF signals and exchanging information packets to wirelessly communicate with a plurality of base stations 102-1, 102-2, and 102-3 (collectively referred to as base stations 102) that may correspond to any combination of base stations 102, 180 in Figure 1A . By extracting different types of information from the exchanged RF signals and leveraging the layout of the wireless communication system 600 (i.e., base station locations, geometries, etc.), UE 104 may determine its location or assist in determining its location in a predefined reference coordinate system. In one aspect, UE 104 may use a two-dimensional coordinate system to specify its location. However, the aspects disclosed herein are not limited thereto and are also applicable to determining location using a three-dimensional coordinate system in cases where an additional dimension is desired. Additionally, although Figure 6 shows one UE 104 and three base stations 102, as will be appreciated, there may be more UE 104s and more or fewer base stations 102.

[0139] 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 in its coverage area so that UE 104 can measure the characteristics of such reference RF signals. For example, Figure 6 illustrates that base station 102-1 transmits a downlink reference signal (PRS) 602 to UE 104, and base stations 102-2 and 102-3 respectively transmit downlink reference signals (PRS) 604 and 606 to UE. UE 104 may use a DL-TDOA (e.g., OTDOA) location method (which is a multi-point location method), in which UE routinely measures the time of arrival (TOA) of reference RF signals (e.g., PRS, CRS, CSI-RS, etc.) transmitted by different pairs of network nodes (e.g., base station 102, antennas of base station 102, etc.). Transmit and / or receive beamforming at the base station and / or UE 104 can achieve broadband bandwidth to improve accuracy. The TOA from a reference base station can be subtracted from the TOA from several neighboring base stations to determine the RSTD of the base station pair.

[0140] Generally, RSTD is measured between a reference network node and one or more neighboring network nodes. In Figure 6 the example shown, base station 102-1 may be the serving base station of UE 104 and may further be used as a reference base station, while base stations 102-2 and 102-3 are used as neighboring base stations. For any single location use of OTDOA, the reference network node remains the same for all RSTDs measured by UE 104 and will generally correspond to the serving cell of UE 104 or another nearby cell with good signal strength at UE 104. In one aspect, in the case where the measured network nodes are cells supported by a base station, the neighboring network nodes will generally be cells supported by a base station different from the base station for the reference cell and may have good or bad signal strength at UE 104. RSTD is generally the relative timing difference between two cells (e.g., the reference cell and the neighboring cell), and this relative timing difference is determined based on the minimum time difference between two subframe boundaries from two different cells.

[0141] Location calculation may be based on the measured time difference (e.g., RSTD) and knowledge of the location and relative transmission timing of the network nodes (e.g., regarding whether the network nodes are accurately synchronized or whether each network node transmits with a known time difference relative to other network nodes).

[0142] To assist in location operations, for a reference network node (e.g., Figure 6 base station 102-1 in the example of Figure 6in the example of base stations 102-2 and 102-3), Figure 1A the location server 172 shown in (e.g., Figure 2B the LMF 270 shown in) may provide OTDOA assistance data to the UE 104. For example, the assistance data may provide the center channel frequency of each network node, various reference signal configuration parameters (e.g., the number of consecutive positioning subframes, the periodicity of positioning subframes, the silence sequence, the frequency hopping sequence, the reference RF signal ID, the reference RF signal bandwidth), the network node global ID, and / or other cell-related parameters applicable to OTDOA, as described above. The OTDOA assistance data may also indicate the serving cell of the UE 104 as the reference network node.

[0143] In one aspect, while the location server 172 (e.g., the LMF 270) may send data to the UE 104, alternatively, the assistance data may directly originate from the network nodes (e.g., the base stations 102) themselves (e.g., in periodically broadcast overhead messages, etc.). Alternatively, the UE 104 may detect neighbor network nodes on its own without using the assistance data.

[0144] In Figure 6 the example of, the time differences measured between the reference cell of the base station 102-1 and the neighboring cells of the base stations 102-2 and 102-3 are represented as τ2–τ1 and τ3–τ1, where τ1, τ2, and τ3 represent the reception times at which the UE 104 receives the reference RF signals from the transmit antennas of the base stations 102-1, 102-2, and 102-3, respectively, and include any measurement noise at the UE 104. Then, the UE 104 may convert the ToA measurements for different network nodes into RSTD measurements (e.g., as defined in 3GPP TS 36.214 titled "Physical layer; Measurements") and (optionally) send them to the location server 172. Using (i) the RSTD measurements, (ii) the known absolute or relative transmit timings of each network node, (iii) the known positions of the physical transmit antennas for the reference network node and the neighboring network nodes, and / or (iv) the directional reference RF signal characteristics (such as the direction of transmission), the location of the UE 104 may be determined (by the UE 104 or the location server 172 (e.g., the LMF 270)).

[0145] For the shortest path from base station i, the ToA T at the UE 104 i is where D i is the one with the position (q i) The Euclidean distance between base station i and UE 104 with position (p), c is the speed of light in air (299700 km / s), and q i is known through the cell information database. The Euclidean distance (i.e., the straight-line distance between two points) is given by:

[0146]

[0147] where D is the distance between two points on the Earth's surface, R is the radius of the Earth (6371 km), are the latitudes of the first point (in radians) and the second point (in radians), respectively, and β1, β2 are the longitudes of the first point (in radians) and the second point (in radians), respectively.

[0148] To identify the ToA of the 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) is transmitting the reference RF signal, and performs an inverse Fourier transform to convert the received RF signal into the time domain. The conversion of the received RF signal into the time domain is referred to as the estimation of the channel energy response (CER). The CER shows the peak varying with time on the channel, and thus the earliest "significant" peak should correspond to the ToA of the reference RF signal. Generally, the UE will use a noise-related quality threshold to filter out spurious local peaks, thereby assuming correct identification of the significant peak on the channel. For example, UE 104 can select the ToA estimate that is the earliest local maximum of the CER, which is at least X dB higher than the median of the CER and at most Y dB lower than the main peak on the channel. 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.

[0149] The TOA measurement performed by UE 104 is related to the geometric distance between this UE and base station 102. In a 2-D Cartesian coordinate system, the (known) coordinates of the base station can be labeled as x i =[x i ,y i T , and the (unknown) coordinates of UE 104 can be labeled as x t =[x t ,y t T . The RSTD measurement can be defined as the time difference (modulo 1 subframe (1 - ms)) between two base stations, and thus corresponds to the range difference between adjacent base stations 102 - i and reference base station 102 - 1.

[0150] ​​

[0151] In Equation 2, RSTD i,1 is the time difference between adjacent base station 102-i and reference base station 102-1 measured at UE 104, (T i - T1) is the transmit time offset between these base stations, referred to as the "real time difference" (RTD); n i and n1 are UETOA measurement errors, and c is the speed of light.

[0152] At least two adjacent base stations are required to measure i, but more than two adjacent base station measurements are desirable, and the system of equations can be solved using least squares or weighted least squares methods. In a synchronous network, the transmit time offset (Ti - T1) should (ideally) be zero, and the above equation defines the time difference of arrival (TDOA). Geometrically, each TDOA defines a hyperbola, where the width of the hyperbola is determined by the TDOA error (ni - n1), as Figure 6 shown. If the coordinates of base station 102 and the transmit time offset (Ti - T1) are known at location server 172 (e.g., LMF 270) or at UE 104, then the location of UE 104 can be determined. The uncertainty of the base station 102 coordinates or the transmit time offset will directly affect the accuracy of the UE location estimate. Additional sources of delay or error are due to the UE and gNB hardware group delays, which are mainly due to the internal hardware delays between the baseband (BB) components and antennas (ANT) at the UE and gNB. The hardware group delay can contribute to timing errors and / or calibration errors that can affect the positioning measurement, which in turn can affect the positioning performance.

[0153] Therefore, for conventional OTDOA measurements, very accurate and reliable network synchronization is important for accuracy. At the speed of light, each nanosecond of timing error translates to approximately one foot (about 0.3 m) of positioning error. As the inter-base station synchronization degrades, the OTDOA measurements become less accurate, e.g., Figure 6 the hyperbola shown in, and the positioning error increases proportionally. However, the synchronization requirements for OTDOA are more stringent compared to the synchronization requirements for communication purposes.

[0154] Uplink time difference of arrival (UTDOA) is a positioning method similar to OTDOA, but based on uplink reference RF signals, e.g., UL PRS or SRS transmitted by the UE (e.g., UE 104). Additionally, transmit and / or receive beamforming at the network node and / or UE 104 can achieve broadband bandwidth at the cell edge for increased accuracy. Beam refinement can also utilize the channel reciprocity procedure in 5G NR. Similar to OTDOA, the lack of synchronization during UTDOA positioning results in accuracy degradation.

[0155] Figure 7 An exemplary wireless communication system 700 is shown that illustrates positioning using uplink time difference of arrival (TDOA) techniques. Figure 7 Similar to that discussed above Figure 6 , but illustrates UTDOA as opposed to OTDOA. As shown, UE 104 transmits SRS 702 to base station 102-1 and simultaneously transmits SRS 704 and SRS 706 to adjacent base stations 102-2 and 102-3, respectively. In some embodiments, SRS 702, SRS 704, and SRS 706 may be the same transmission. In other embodiments, SRS 702, SRS 704, and SRS 706 may be separate transmissions, where 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.

[0156] Assuming that base stations 102 are synchronized, the RSTD for SRS 702 and 704 can be determined based on the difference between the reception times of SRS 702 and SRS 704 at base stations 102-1 and 102-2, respectively, minus any delay (if any) between the transmissions of SRS 702 and 704 at UE 104. Similarly, the RSTD for SRS 702 and 706 can be determined based on the difference between the reception times of SRS 702 and SRS 706 at base stations 102-1 and 102-3, respectively, minus any delay (if any) between the transmissions of SRS 702 and 706 at UE 104. Similar to the above discussion, the location of UE 104 can thus be determined based on the intersection of the resulting hyperbolas.

[0157] Although such as Figure 6 and Figure 7The positioning techniques shown (such as DL TDOA and UL TDOA) generally involve measurement procedures between a target UE and multiple base stations. However, in some designs, a reference device associated with a known location may participate in one or more positioning procedures. For example, sidelink positioning can be used in the measurement procedure to replace one or more base stations. The sidelink positioning can use, for example, another UE or other device with a known position that can communicate with the target UE 104 via sidelink communication. Using sidelink for positioning may be desirable because it allows for more flexible deployment with anchor devices in the form of UEs. For example, in an environment where satellite-based positioning (such as Global Navigation Satellite System (GNSS)) or network positioning is impaired. For example, in an indoor environment (such as a shopping mall, manufacturing factory, etc.) or in an urban canyon, the GNSS or network signals for positioning may be poor, or there may be multipath components, interference, etc. that make positioning difficult. Additionally, sidelink positioning can operate independently of network coverage and thus may have lower latency because it does not require establishing a network connection before positioning. Sidelink positioning also allows for relative positioning that does not require absolute positioning calculations. For example, in public safety operations (such as tracking emergency responders), vehicle applications (such as platooning, collision avoidance), unmanned aerial vehicle (UAV) applications (such as approaching a docking point or landing), augmented reality (AR) applications (such as user interactions within AR), smart home entertainment applications (such as connection and interaction between devices), etc., relative positioning using sidelink may be useful.

[0158] Reference devices (such as a UE with the most recent positioning lock, a roadside unit (RSU), etc.) can be configured to support downlink-related positioning such as DL-TDOA, uplink-related positioning such as UL-TDOA, or a combination of downlink and uplink-related positioning such as RTT. The reference device can be configured to support the measurement of DL-PRS (or sidelink (SL-PRS)) and report the associated measurements (such as RSTD, RxTx time difference, RSRP) to the LMF (or to the UE for UE-based positioning), transmit UL-PRS (or SL-PRS) and report the associated measurements (such as Tx time, RxTx time difference, etc.). The reference device may sometimes be referred to herein as an anchor device for positioning. Additionally, a base station may sometimes also be referred to as a (stationary) anchor device for positioning.

[0159] Figure 8 A timing diagram 800 of TDOA measurement signals exchanged between a target UE 104 and a stationary anchor (such as BS A (e.g., base station 102), reference device B (e.g., a UE 104 with a known position or another base station 102)) is shown by way of example. In this example, BS A and reference device B are stationary and have known positions.Figure 8 The timing diagram 800 shows that the difference (T_RxTx) between the reception Rx time of PRS#1 and the transmission time of PRS#2 of the reference device B is represented as τ B , 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 represented as τ UE , and as used herein and represent measured values.

[0160] TDOA-based positioning heavily relies on network synchronization (between gNBs) to achieve positioning accuracy. By introducing a reference device (UE or gNB) with a known stationary position (hereinafter referred to as reference device B), by substituting the anchor-to-anchor time measurement T oF (A,B) (Rx - Tx time difference) into the calculation of RSTD (T RSTD = T oF (B,UE) - T oF (A,UE)), the requirement for gNB synchronization can be relaxed, whereby

[0161]

[0162] where T oF (time of flight) is the propagation time between two nodes, and the T oF (A,B) between BS A and the reference device B can be obtained from the almanac information (for example, since the positions of BS A and the reference device B are known, the propagation delay between BS A and the reference device B can be calculated instead of measured).

[0163] Assuming a constant clock drift during the short period τ, the measured where e is the clock drift that can be ±0.1 ppm for both the UE and the gNB. The error mainly depends on For example:

[0164]

[0165] where τ B (e UE - e B ) is the main part of the error, and (e UE - e B ) can be ±0.2 ppm.

[0166] In some systems, this level of error may be unacceptable. For example, in some designs, the average of the fundamental measurements of the carrier frequency that the UE is to modulate may be required to be accurate to within ±0.1 PPM as observed over a 1 ms period of the cumulative measurement interval, compared to the carrier frequency received from the NRB node.

[0167] In some designs, the error due to time drift mainly depends on the PRS#1 to PRS#2 gap (τ B ). For the increased accuracy requirements in 3GPP Release 17 (e.g., 1 m for general commercial use, or 20 cm for IIoT), assuming a 10% error budget for cumulative ±0.2 ppm, the maximum required PRS#1 to PRS#2 gaps can be 1.67 milliseconds and 0.33 milliseconds respectively, e.g.:

[0168]

[0169] Figure 9 An exemplary process 900 of the TDOA procedure is shown, which uses time drift mitigation to improve the positioning accuracy of the positioning estimate of the target UE 104. In Figure 9 which, 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 position or another base station 102), and the target UE 104. In this example, BS A and reference device B are stationary and have known positions.

[0170] For context, the baseline DL-TDOA algorithm is where the associated error is [T oF (A,B)+T oF (B,UE)-T oF (A,UE)]e UE +τ B,1 (e UE -e B )). However, this baseline DL-TDOA algorithm can be compensated for time drift, e.g.:

[0171]

[0172] where T oF (A,B) between BS A and reference device B 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 rather than measured). In this case, the error can be e A [T oF(A,B)+T oF (B,UE)-T oF (A,UE)], which is lower than the error of the baseline DL - TDOA algorithm as described above in Equation 4. For effectiveness, the drift correction reference duration must be long to be effective, otherwise the multiplication correction factor such as will be the constant 1.

[0173] In one example, paired RSTDs (which are associated with paired PRSs (PRS#1 and #3) from BS A and another PRS (PRS#2) from reference device B) can be measured by the target UE 104, for example, to obtain and For UE - assisted positioning, the measured RSTD is reported to the LMF. An alternative option is to report the ratio associated with In some designs, paired RxTx time differences (which are associated with paired PRSs (PRS#1 and #3) from BS A) can be measured by reference device B - for example, to obtain and For UE - assisted positioning, the paired RxTx time differences are reported to the LMF. For UE - based positioning, the paired RxTx time differences are reported to the UE. An alternative option is to report the ratio associated with related.

[0174] The use of a reference device (such as Figure 8 and Figure 9 reference device B in) is premised on the reference device being stationary. However, a stationary reference device may not be available in all environments. For example, in some environments, there may be a reference device with a known location available for positioning, but the reference device can be mobile. By way of example, a mobile reference device with a known location can be a vehicle UE.

[0175] For example, in a vehicle - to - everything (V2X) wireless system, a mobile vehicle UE can be used as multiple reference devices (anchors) over time for positioning a relatively stationary target UE (e.g., a UE held by a pedestrian).

[0176] Figure 10 For example, wireless communication system 1000 is shown, which shows vehicle - to - everything (V2X) communication for using downlink time - difference - of - arrival (TDOA) techniques with a fixed (stationary) anchor 1002 and a mobile anchor 1006 to position target UE 104. It should be understood that, Figure 10Shows a single moving anchor point 1006 at multiple times (t1, t2, t3, and t4), showing the change in the positioning of the moving anchor point 1006 relative to the target UE 104 over time. For example, the moving anchor point 1006 is shown as a dashed line at times t2, t3, and t4 and is lighter in color than the color shown at time t1.

[0177] In some specific implementations, the wireless communication system 1000 can be a cellular V2X (C-V2X) system. Generally speaking, there are two operating modes for V2X services, as defined in the 3rd Generation Partnership Project (3GPP) TS23.285. One operating mode uses direct wireless communication between V2X entities (e.g., the target UE 104, the fixed anchor point 1002, and the moving anchor point 1006). Another operating mode uses network-based wireless communication between entities. These two operating modes can be combined, or other operating modes can be used if needed.

[0178] As Figure 10 shown, the wireless communication system 100 can operate using direct or indirect wireless communication between the target UE 104, the fixed anchor point 1002, and the moving anchor point 1006. For example, the wireless communication can be through, for example, the Proximity-based Services (ProSe) direct communication (PC5) reference point defined in 3GPP TS23.303, and can use wireless communication based on IEEE 1609, Wireless Access in Vehicular Environments (WAVE), Intelligent Transportation Systems (ITS), and IEEE 802.11p, on the ITS band at 5.9 GHz, or other wireless connections directly between entities. The wireless communication system 100 can use, for example, the Vehicle-to-Everything (V2X) communication standard, where information is transferred between vehicles and other entities within the wireless communication network. V2X services include, for example, services for Vehicle-to-Vehicle (V2V), Vehicle-to-Pedestrian (V2P), Vehicle-to-Infrastructure (V2I), and Vehicle-to-Network (V2N). The V2X standard aims to develop autonomous or semi-autonomous driving systems (such as ADAS), which help drivers make critical decisions (such as lane changes, speed changes, overtaking speeds) and can be used to assist with parking, as discussed herein. Low-latency communication is used in V2X and is therefore suitable for precise relative positioning, for example, using RTT, TDOA, etc.

[0179] In some specific implementations, the fixed anchor point 1002 can 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 can be a logical entity that combines V2X application logic with the functions 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 UE (referred to as a UE-type RSU). The fixed anchor point 1002 (if it is an RSU), together with one or more of the UE 104 and the mobile anchor point 1006, can communicate with the base station 102 via the communication channel 120. In some specific implementations, the fixed anchor point 1002 can be the base station 102 or another UE 104 that is stationary and has a known location.

[0180] As shown in the figure, the target UE 104, the fixed anchor point 1002, and the mobile anchor point 1006 can directly transmit and emit positioning signals that can be used for positioning, such as DL PRS, UL PRS (SRS for positioning), or SL PRS. For example, the target UE 104 and the fixed anchor point 1002 can directly transmit and emit positioning signals using the communication link 1005, the target UE 104 and the mobile anchor point 1006 can directly transmit and emit positioning signals using the communication link 1007, and the fixed anchor point 1002 and the mobile anchor point 1006 can directly transmit and emit positioning signals using the communication link 1003. The PRS broadcast by the target UE 104, the fixed anchor point 1002, and the mobile anchor point 1006 can be any signal suitable for positioning, such as a signal defined for DSRC or C-V2X. The PRS can be broadcast on licensed or unlicensed spectrum. For example, in some specific implementations, the PRS can be broadcast on one or more unlicensed National Information Infrastructure (UNII) radio frequency bands, including, for example, one or more of the UNII-1 radio frequency band, the UNII-2A radio frequency band, the UNII-2B radio frequency band, or the UNII-3 radio frequency band. When broadcasting on unlicensed spectrum, a listen-before-talk (LBT) protocol can be employed.

[0181] The mobile anchor 1006 can be a vehicle UE (or other mobile entity) with an accurate location during a time period while performing TDOA measurements. For example, at a first time (t1) during the TDOA positioning of the target UE 104, the mobile anchor 1006 can have an accurate location, e.g., due to GNSS or terrestrial positioning technology. At subsequent times (e.g., at times t2, t3, and t4) during the TDOA positioning of the target UE 104, the mobile anchor 1006 can have a known location, e.g., due to dead reckoning based on the initial location at time t1 and mobility information (including speed, yaw / pitch / roll, acceleration, etc.) provided by in-vehicle sensors of the vehicle such as accelerometers, gyroscopes, wheel odometry sensors, etc. Additionally or alternatively, GNSS or terrestrial positioning technology can be used, for example, to obtain an updated location of the mobile anchor 1006 at subsequent times.

[0182] For a mobile anchor, as Figure 9 The TDOA algorithm for compensating drift as shown in Equation 6 cannot be extended in a straightforward manner. For example, as discussed, for it to be effective, Figure 9 The drift correction reference duration shown must be long to be effective, otherwise the multiplicative correction factor, e.g., will be the constant 1. If Figure 9 the reference device B in

[0183] is moving, then during the long time period between the BS A transmitting PRS#1 and PRS#3, the reference device B will move away from its initial location. For example, for a vehicle moving at a speed of 30 m / s, a 200 ms drift correction reference duration between PRS#1 and PRS#3 will cause the reference device B to travel 6 m from its initial position. Figure 9 Figure 10 Figure 9

[0184] Figure 11

[0185] Figure 11 An exemplary process 1100 of the TDOA procedure is shown by way of example, which uses time drift mitigation of the mobile anchor to improve the positioning accuracy of the positioning estimate of the target UE 104.

[0185] In Figure 11In this case, measurement signals are exchanged among an anchor point A 1002 (which can be an RSU, another UE with a known position, a base station 102, etc.), a mobile anchor point B 1006 (which can be a vehicle UE or other mobile UE), and a target UE 104. In Figure 11 this case, the anchor point A 1002 and the target UE 104 are relatively stationary, and the mobile anchor point B 1006 is moving and is thus regarded as several virtual anchor points. For example, Figure 11 the same mobile anchor point B 1006 is shown as three virtual anchor points (i.e., mobile anchor point B 1006, mobile anchor point B' 1006, and mobile anchor point B'' 1006), which are in different relative positions with respect to the target UE 104 over time (shown as separate timelines t1, t2, and t3 respectively). For example, the timelines t1, t2, and t3 correspond to Figure 10 the times t1, t2, and t3 shown in Figure 11 this case. In addition, the set of RSTD generated by the signaling exchange for the TDOA procedure in Figure 11 this case is shown as three RSTD measurement instances 1110, 1120, and 1130 identified by a dotted box, each of which is associated with the mobile anchor point 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 shown in the set of RSTD in Figure 10 this case, additional RSTD measurement instances can be included in the set of RSTD if desired, for example, corresponding to Figure 10 the time t4 (and additional times) shown in Figure 10 this case. The TDOA determined from the RSTD measurement instances 1110, 1120, and 1130 at times t1, t2, and t3 defines Figure 10 the hyperbolas 1010, 1020, and 1030 shown in

[0186] such that Figure 11 these hyperbolas intersect at the position of the target UE 104. Therefore, using the known positions of the anchor point A 1002 and the mobile anchor point B 1006 at each of the times t1, t2, and t3, the location of the target UE 104 can be determined.

[0186] As Figure 11 shown in the set of RSTD in

[0187] this case, the fixed anchor point A 1002 transmits reference signals (PRS) for multiple 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 mobile anchor point B 1006 transmits corresponding reference signals (PRS) in multiple RSTD measurement instances (e.g., PRS#2, PRS#4, and PRS#6 transmitted in the RSTD measurement instances 1110, 1120, and 1130).

[0187] In RSTD measurement instance 1110, anchor A 1002 transmits PRS#1, which is received by mobile anchor B 1006 (at time t1) and by target UE 104. In response to receiving PRS#1, after a time period τ B,1 mobile anchor B 1006 transmits PRS#2, which is received by target UE 104. In RSTD measurement instance 1120, after drift correction reference duration T_PRS#1 to #3, anchor A 1002 transmits PRS#3, which is received by mobile anchor B’ 1006 (at time t2) and by target UE 104. In response to receiving PRS#3, after a time period τ B′,3 mobile anchor B’ 1006 transmits PRS#4, which is received by target UE 104. In RSTD measurement instance 1130, after 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 (at time t3) transmits PRS#6, which is received by target UE 104. It should be noted that in RSTD measurement instance 1130, mobile anchor B” 1006 does not need to receive PRS#6 or monitor the time period between receiving PRS#5 from anchor UE 1002 and transmitting PRS#6 to target UE 104.

[0188] As shown in respective RSTD measurement instances 1110 and 1120, mobile anchor B 1006 at time t1 and 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 target UE 104. Since these RSTD measurement instances 1110 and 1120 involve 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 labeled τ B,1 and is labeled as when measured by mobile anchor B 1006, while in RSTD measurement instance 1120, the RxTx time difference between receiving PRS#3 and transmitting PRS#4 is labeled τ B′,3 and is labeled as

[0189] The RxTx time difference measured in two RSTD measurement instances can be used to determine the clock drift error that can be caused by the non-ideal synchronization between the anchor point A 1002 and the mobile anchor point B 1006. In the case of using two RSTD measurement instances (e.g., RSTD measurement instances 1110 and 1120) to determine the clock drift error, additional RSTD measurement instances (RSTD measurement instance 1130) can be measured for the RSTD set without an anchor-to-anchor procedure, that is, without measuring the RxTx time difference between receiving the reference signal (PRS) from the anchor point A 1002 and transmitting the reference signal (PRS) to the target UE 104. If desired, in the case where the clock drift error has been determined, the RSTD set can include multiple RSTD measurement instances without an anchor-to-anchor procedure.

[0190] It should be understood that although Figure 11 two adjacent RSTD measurement instances including an anchor-to-anchor procedure are shown (i.e., RSTD measurement instances 1110 and 1120), one or more intermediate RSTD measurement instances can exist without an anchor-to-anchor procedure if desired.

[0191] The clock drift error caused by the non-ideal synchronization between the anchor point A 1002 and the mobile anchor point B 1006 can be identified as follows. As Figure 11 can be seen in

[0192] τ UE,1 =[T oF (A,B)-T oF (A,UE)]+τ B,1 +T oF (B,UE). Equation 7

[0193] Therefore, for non-ideal anchor synchronization, the baseline DL-TDOA algorithm for RSTD measurement instance 1110 can be written as:

[0194]

[0195] If the time gap (configured time slot offset, in milliseconds) between the transmissions of PRS#1 and PRS#2 is specified as T PRS#1至#2 , then for ideal anchor synchronization, the baseline DL-TDOA algorithm can be written as:

[0196]

[0197] Therefore, the synchronization deviation can be determined by subtracting Equation 8 from Equation 9, resulting in:

[0198]

[0199] Similarly, for PRS #3 and PRS #4 in RSTD measurement instance 1120, the synchronization deviation can be written as:

[0200]

[0201] Assuming that the change in the anchor synchronization deviation is only attributed to clock drift, (where e A is the error at anchor A 1002 and e B is the error at the mobile anchor B 1006), then the synchronization deviation of PRS #3 and PRS #4 can be written as:

[0202] Δ anchorsync,3 = Δ anchorsync,1 + (e B - e A ) T PRS#1-to-#3 , Equation 12

[0203]

[0204] Therefore, as can be seen in Equation 13, the clock drift error (e B - e A ) is dependent on the measured quantities, which include the RxTx time difference (τ B,1 ) measured by the mobile anchor B 1006 at time t1 in the RSTD measurement instance 1110 and the RxTx time difference (τ B,2 ) measured by the mobile anchor B' 1006 at time t2 in the RSTD measurement instance 1120.

[0205] Having determined the clock drift error (e B - e A ), additional RSTD measurement instances (e.g., RSTD measurement instance 1130) can be estimated without an anchor-to-anchor procedure. For example, under the non-ideal synchronization assumption for anchor A1002 and the mobile anchor B", at time t3, the DL-TDOA algorithm for the RSTD measurement instance 1130 can be written as:

[0206]

[0207] Δ anchorSync,5 can be written as:

[0208] Δ anchorSync,5 = Δ anchorsync,1 + (e B - e A ) T PRS#1-to-#5 , Equation 15

[0209] Therefore, when measuring a set of RSTDs with an anchor moving over time (moving anchor B 1006), only two RSTD measurement instances ( Figure 11 shown as Figure 11 RSTD measurement instances 1110 and 1120 in Figure 11 ) are needed for clock drift error mitigation. One or more of the remaining RSTD measurement instances (shown as RSTD measurement instance 1130 in

[0210] ) are not needed for determining clock drift error mitigation and thus no anchor-to-anchor procedure is required.

[0210] It should be understood that the anchor-to-anchor procedure that produces the RxTx time difference of the two corresponding PRS sets transmitted by anchor A 1002 and moving anchor B 1006 can be measured by moving anchor B 1006 (as Figure 11 shown), or can be measured by anchor A 1002.

[0211] Figure 12 An exemplary process 1200 of the TDOA procedure is shown by way of example, which uses time drift mitigation of the moving anchor to improve the positioning accuracy of the positioning estimate of target UE 104. Figure 12 The process 1200 shown in Figure 11 is similar to the process 1100 shown in Figure 11 , but shows the RxTx time difference labeled τ B,1 between receiving PRS#1 (transmitted at time t1) from moving anchor B 1006 and transmitting PRS#2 to target UE 104 in RSTD measurement instance 1210, which can be measured by fixed anchor A1002 as and the RxTx time difference labeled τ B′,3 between receiving PRS#3 (transmitted at time t2) from moving anchor B’1006 and transmitting PRS#4 to target UE 104 in RSTD measurement instance 1220, which can be measured by fixed anchor A 1002 as while no RxTx time difference needs to be measured or reported in RSTD measurement instance 1230.

[0212] Figure 13 are transmitted by anchor A 1002 and moving anchor B 1006 for use as Figure 11Description of generating a set of reference signals (PRS) for RSTD measurements by clock drift error mitigation as discussed in. The set of RSTD measurements generated over time for target UE 104 is defined by a first PRS instance set 1302 of PRS transmitted by fixed anchor A 1002 and a second PRS instance set 1304 of PRS transmitted by mobile anchor B 1006, where corresponding PRS pairs from the first PRS instance set 1302 and the second PRS instance set 1304 generate RSTD measurement instances 1310, 1320, 1330, and 1340 identified by the dotted boxes.

[0213] As described above, only two RSTD measurement instances are required for clock drift error mitigation. Therefore, for this set of RSTD generated using mobile anchor B 1006, only two anchor-to-anchor measurements are required, i.e., the RxTx time difference between two PRS of the first PRS instance set 1302 of PRS from anchor A 1002 and the corresponding two PRS of the second PRS instance set 1304 of PRS from mobile anchor B 1006 (e.g., in the PRS pairs in RSTD measurement instances 1310 and 1330) should be measured and reported (e.g., reported to the location server or target UE 104) by mobile anchor B 1006 or by fixed anchor A 1002, as Figure 12 shown in.

[0214] The two PRS instances for anchor-to-anchor RxTx time difference measurement should have the same RxTx timing error group (TEG) identification (ID) such that the difference in RxTx time difference measurements (e.g., ) can mitigate some additive group delays. The two PRS transmitted by either of the two anchors in the two PRS instances (e.g., Figure 11 or Figure 12 PRS#1 and PRS#3 or PRS#2 and PRS#4 shown in ) should have the same Tx TEG ID such that it can be assumed that the drift error increases linearly over time, e.g., without synchronization adjustment between PRS#1 and PRS#3 or between PRS#2 and PRS#4.

[0215] In some embodiments, for example Figure 11 or Figure 12 the set of RSTD measurements for target UE 104 shown in can be triggered by a network entity or by fixed anchor A 1002. This trigger can be based on a location request from target UE 104 before triggering this set of RSTD measurements. For example, the trigger message can indicate the first PRS instance set of PRS resources ( Figure 13 the PRS instance set 1302 from anchor A 1002 in ) and the second PRS instance set of PRS resources ( Figure 13The set of PRS instances 1304 from the mobile anchor B1006) in is associated with the set of RSTD measurements. For example, in some specific implementations, the first set of PRS instances of the PRS resources from the anchor A 1002 and the second set of PRS instances of the PRS resources from the mobile anchor B 1006 for the RSTD measurements selected may have the same periodicity.

[0216] In addition, two RSTD measurement instances for anchor-to-anchor RxTx time difference measurement may be indicated in the trigger message. The two anchor-to-anchor RxTx time difference measurements measured by the mobile anchor B 1006 or the anchor A 1002 may be reported to the location calculation entity, i.e., the target UE 104 or the location server 172 (e.g., the LMF 270).

[0217] PRS resources from the mobile anchor B 1006 may be reserved. For example, the set of PRS instances of the PRS resources transmitted by the mobile anchor B 1006 ( Figure 13 the set of PRS instances 1304 in) may be reserved by a network entity or by the fixed anchor A 1002. In addition, the set of PRS instances of the PRS resources transmitted by the mobile anchor B 1006 ( Figure 13 the set of PRS instances 1304 in) may have a lifetime, e.g., the number of periodicities.

[0218] Figure 14 Message flow 1400 shows the message passing between the location server 172, the anchor A 1402, the anchor B 1404, and the target UE 104 for supporting TDOA positioning of the UE using RSTD measurements from the mobile anchor, as discussed herein. For example, the location server 172 may be the LMF 270. In one specific implementation, the anchor A 1402 may be the fixed anchor A1002, and the anchor B 1404 may be the mobile anchor B 1006 that performs two anchor-to-anchor RxTx time difference measurements, as Figure 11 shown in. In another specific implementation, the anchor A 1402 may be the mobile anchor B 1006 that performs two anchor-to-anchor RxTx time difference measurements, and the anchor B 1404 may be the fixed anchor A 1002 as Figure 12 shown in. For ease of reference Figure 14 , the anchor A 1402 will be assumed to be the fixed anchor, while the anchor B 1406 will be assumed to be the mobile anchor, but it should be understood that, without loss of generality, in Figure 14 the anchor A 1402 may be the mobile anchor, and the anchor B may be the fixed anchor. It should be understood that, Figure 14Messages related to TDOA positioning of a target UE using the RSTD measurements discussed herein are shown, but additional messages (including conventional LPP messages) or fewer messages may be included in message flow 1400. For example, messaging for establishing a positioning session and for determining the capabilities of UE 104 may or may not be exchanged or assistance data may not be included.

[0219] In phase 1, location server 172 may send assistance data to UE 104, for example, in an LPP assistance data message. The assistance data may include PRS configuration information for anchor points 1402 and 1406 and may identify the fixed anchor point 1402 and the mobile anchor point 1406. The assistance data may also include, for example, the location of the fixed anchor point for the UE-based positioning process. Location server 172 may provide the PRS configuration information of the PRS resources that the target UE 104 is to receive from anchor point A 1402 and anchor point B 1406.

[0220] In phase 2, location server 172 may send the PRS configuration information to anchor points 1402 and 1406 for transmission to the target UE 104. Location server 172 may further provide to anchor point B 1406 the PRS configuration information of the PRS resources to be transmitted by anchor point A 1402 and to be detected by anchor point B 1406. Location server 172 may, for example, indicate the set of PRS instances of the PRS resources to be transmitted by anchor point A 1402 and the set of PRS instances of the resources to be transmitted by anchor point B 1406 that are associated with this set of RSTD measurements of UE 104. For example, the set of PRS instances of the PRS resources may be selected to have the same periodicity. Location server 172 may indicate the RSTD measurement instances of the anchor-to-anchor RxTx time difference measurement performed by anchor point B 1406. The PRS in the anchor-to-anchor RxTx time difference measurement may have the same RxTx TEG ID. In addition, the PRS transmitted by the stationary anchor entity, such as anchor point A 1402, for two anchor-to-anchor RxTx time difference measurements may have the same Tx TEG ID, and / or the PRS transmitted by the mobile anchor entity, such as anchor point B 1406, for two anchor-to-anchor RxTx time difference measurements may have the same Tx TEG ID. The set of PRS instances of the PRS resources to be transmitted by the mobile anchor point B 1406 may be reserved by a network entity (e.g., location server 172) or by the fixed anchor point A 1402. In addition, the set of PRS instances of the PRS resources to be transmitted by the mobile anchor point B 1406 may have a lifetime, e.g., a number of periodicities. The PRS to be transmitted by the mobile anchor point B 1406 may be reserved by the fixed anchor point A 1402. In some specific implementations, the PRS configuration information may be sent by the fixed anchor point A 1402 instead of the location server 172.

[0221] In stage 3, the location server 172 may send a location information request to the UE 104, for example, in an LPP request location information message. For example, the location information request or another message may trigger this set of RSTD measurements of the target UE 104. In some specific implementations, a stationary anchor entity (e.g., anchor A 1402) may send a trigger message to the target UE 104. This trigger request may be in response to a location request for the target UE 104. In some specific implementations, the trigger message (e.g., location information request) may provide PRS resource information for the PRS resources from the anchor entity for the purpose of performing measurements for this set of RSTD measurements. For example, the request may be for RSTD measurements for UE-assisted positioning or for location estimation (and optionally, RSTD measurements) for UE-based positioning.

[0222] Boxes 1410, 1420, and 1430 illustrate different RSTD measurement instances over time during which the positioning of the mobile anchor B 1406 relative to the target UE 104 changes, and thus the mobile anchor B 1406 serves as multiple virtual anchors for the RSTD measurement instances. The mobile anchor B 1406 may perform and report anchor-to-anchor RxTx time difference measurements for clock drift error mitigation only in two RSTD measurement instances (shown as RSTD 1410 and 1420).

[0223] At stage 4 in the RSTD measurement instance 1410, the anchor 1402 transmits a reference signal (e.g., DL PRS) to the target UE 104 and the anchor 1406. The transmission of the PRS to the anchor 1406 may occur simultaneously with the transmission of the PRS to the target UE 104, or may occur after a transmission delay that is measured and reported and that may be used in the RSTD measurement.

[0224] At stage 5 of the RSTD measurement instance 1410, the anchor 1406 transmits a reference signal (e.g., SL or DL PRS) to the target UE 104.

[0225] At stage 6 in the RSTD measurement instance 1410, the anchor 1406 measures the first RxTx time difference between receiving the PRS from the anchor 1402 in stage 4 and transmitting the PRS to the target UE 104 in stage 5. The anchor 1406 may further record the transmission time T_tx of the PRS transmitted to the target UE 104 in stage 5. The anchor 1406 additionally records its positioning during the RSTD measurement instance 1410, which may be determined, for example, from accurate GNSS and / or ground measurements that coincide with the RSTD measurement instance 1410, or may be based on a previously determined accurate positioning (e.g., GNSS and / or ground measurements) updated using sensor information in a dead reckoning procedure, as discussed above.

[0226] At stage 7 in RSTD measurement instance 1420, anchor 1402 transmits a reference signal (e.g., DL PRS) to target UE 104 and anchor 1406. Similar to stage 4, the transmission of the PRS to anchor 1406 can occur simultaneously with the transmission of the PRS to target UE 104, or can occur after a transmission delay that is measured and reported and can be used in RSTD measurements.

[0227] At stage 8 of RSTD measurement instance 1420, anchor 1406 transmits a reference signal (e.g., SL or DL PRS) to target UE 104, similar to stage 5.

[0228] At stage 9 in RSTD measurement instance 1420, anchor 1406 measures the second RxTx time difference between receiving the PRS from anchor 1402 in stage 7 and transmitting the PRS to target UE 104 in stage 8. Anchor 1406 can further record the transmission time T_tx of the PRS transmitted to target UE 104 in stage 8. Anchor 1406 additionally records its location during RSTD measurement instance 1420, similar to stage 6, which can be determined, for example, using GNSS and / or terrestrial measurements or dead reckoning using accurate GNSS and / or terrestrial measurements via sensor information.

[0229] At stage 10 of RSTD measurement instance 1430, anchor 1402 transmits a reference signal (e.g., DL PRS) to target UE 104. The PRS transmitted in stage 10 does not need to be transmitted to or received by anchor 1406.

[0230] At stage 11 of RSTD measurement instance 1430, anchor 1406 transmits a reference signal (e.g., SL or DL PRS) to target UE 104, similar to stage 8. Different from 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 stage 10. Anchor 1406 can further record the transmission time T_tx of the PRS transmitted to target UE 104 in stage 11. However, anchor 1406 can additionally record its location during RSTD measurement instance 1430, similar to stage 6, which can be determined, for example, using GNSS and / or terrestrial measurements or dead reckoning using accurate GNSS and / or terrestrial measurements via sensor information.

[0231] In stage 12, UE 104 performs positioning measurements using the DL PRS received from anchor point A 1402 and anchor point B 1406 in stages 4 and 5, stages 7 and 8, and stages 10 and 11. The positioning measurements include, for example, an indication of the difference (e.g., time difference (T_Rx - Rx)) between the reception Rx time of the PRS from anchor point A 1402 and the reception time of the PRS from anchor point B 1404 at the target UE 104 (e.g., represented as τ UE,1 , τ UE,3 and τ UE,5 , as shown in Figure 11 and Figure 13 ), or include the reception time.

[0232] In stage 13, anchor point B 1406 provides a measurement report to the position calculation entity (i.e., position server 172) or, in some specific embodiments (shown in dashed lines), to the target UE 104. The measurement report may include the RxTx time difference measurements from RSTD measurement instances 1410 and 1420, the transmission time T_tx of the PRS transmitted in stages 5, 8, and 11, and the positioning information of anchor point B 1406 (e.g., the absolute positioning at each time instance such as stages 5, 8, and 11) (assuming anchor point B 1406 is a mobile anchor point).

[0233] In stage 14, anchor point A 1402 provides a measurement report to the position calculation entity (i.e., position server 172) or, in some specific embodiments (shown in dashed lines), to 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 specific embodiments, if anchor point A 1402 does not provide its positioning in the assistance data in stage 1 (or if anchor point A 1402 is a mobile anchor point), then anchor point A 1402 may provide its positioning.

[0234] At stage 15, shown in a dashed box, for UE-based positioning, the target UE 104 may use TDOA as discussed herein, the positioning measurements performed in stage 12, and the measurement reports received from anchor point B 1406 and anchor point A 1402 in stages 13 and 14 to generate a positioning estimate. For example, the target UE 104 may determine the time of flight T oF between anchor point A 1402 and anchor point B 1406 for each RSTD measurement instance 1410, 1420, 1430 based on the assistance data and the reported positioning of the mobile anchor point (e.g., in stage 13), and use the measured quantities (including the RxTx time difference measured by anchor point B 1406) to determine the clock drift error (e B -e A), as described in reference equation 13, and can be calculated using measurements from RSTD measurement instances 1410, 1420, and 1430 and the clock drift error (e B -e A ) to determine TDOA (as described with reference to Equation 8 and Equation 14, Equation 15). Using the known position of the anchor point (e.g., TDOA received and / or determined in the assistance data in Phase 1), the positioning of UE 104 can be estimated using multi-point measurements.

[0235] At stage 16, UE 104 sends location information in an LPP Provide Location Information message to location server 172. The location information may include, for example, the positioning estimate determined from stage 15 and / or the positioning measurement determined at stage 12, such as an indication of the difference between the reception time of the PRS from anchor point A 1402 and the reception time of the PRS from anchor point 1406. For example, the location information may include the difference in reception time or the reception time of the PRSs.

[0236] At stage 17, the location server 172 may determine a location estimate for the target UE 104 or verify a location estimate from the UE 104 based on the location information received in the messages in stages 13, 14, and 16. The location server 172 may use TDOA to determine the location of the target UE 104, as discussed herein. For example, the location server 172 may determine the flight time T between anchor point A 1402 and anchor point B 1406 for each RSTD measurement instance 1410, 1420, 1430 based on the known location of the fixed anchor point and the reported location of the mobile anchor point (e.g., from stage 13). oF , using measurements including the RxTx time difference measured by anchor point B 1406 to determine the clock drift error (e B -e A ), as described in reference equation 13, and using the measurements from RSTD measurement instances 1410, 1420, and 1430 and the clock drift error (e B -e A ) is used to determine TDOA, as described with reference to Equation 7 and Equations 14 and 15. Using the known positions of the anchor points and the determined TDOA, multi-lateration positioning may be used to estimate the location of UE 104.

[0237] Figure 15 1500 is a flowchart showing an exemplary process 1500 for supporting the operation of a positioning estimation entity to determine the position of a target UE. In one specific implementation, the process may be performed by, for example, a location server (such as Figure 1A The location server 172 shown in Figure 2B In one specific implementation, the process may be performed by the target UE (e.g.,Figure 1A performed by the target UE 104 shown in

[0238] At block 1502, a positioning estimation entity may obtain a set of reference signal time difference (RSTD) measurements for a target UE, the set of RSTD measurements including at least three RSTD measurements generated by the target UE at different times, wherein each RSTD measurement in the set of RSTD measurements is generated using a PRS from a first set of positioning reference signal (PRS) instances transmitted by a stationary anchor entity and a corresponding PRS from a second set of PRS instances transmitted by a mobile anchor entity, e.g., as shown in Figures 10 to 13 and Figure 14 phase 12 or phase 16 of. The stationary anchor entity may be, for example, Figures 10 to 13 anchor A 1002 shown in Figure 14 or anchor A 1402 or anchor B 1406 in Figures 10 to 13 The mobile anchor entity may be, for example, mobile anchor B 1006 shown in Figure 14 or anchor A 1402 or anchor B 1406 in Figure 3A A device for obtaining a set of reference signal time difference (RSTD) measurements for a target UE, the set of RSTD measurements including at least three RSTD measurements generated by the target UE at different times, wherein each RSTD measurement in the set of RSTD measurements is generated using a PRS from a first set of positioning reference signal (PRS) instances transmitted by a stationary anchor entity and a corresponding PRS from a second set of PRS instances transmitted by a mobile anchor entity, the device may include: at least one WWAN transceiver 310 or at least one short-range wireless transceiver 320; and at least one processor 332, the at least one processor having dedicated hardware or implementing executable code or software instructions in a memory 340, such as Figure 3C the PRS module 342 in the UE 302 shown in

[0239] At block 1504, the positioning estimation entity may obtain at least two anchor-to-anchor receive transmit (RxTx) time difference measurements, wherein each anchor-to-anchor RxTx time difference measurement is associated with a PRS from the first set of PRS instances and a corresponding PRS from the second set of PRS instances, and wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements, e.g., as shown in Figures 10 to 13 and Figure 14as shown in Stages 6, 9, and 13. A device for obtaining at least two anchor-to-anchor receive-transmit (RxTx) time difference measurements, where each anchor-to-anchor RxTx time difference measurement is associated with a PRS from a first set of PRS instances and a corresponding PRS from a second set of PRS instances, and where the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements, the device may include: at least one WWAN transceiver 310 or at least one short-range wireless transceiver 320; and at least one processor 332 having dedicated hardware or implementing executable code or software instructions in a memory 340, such as Figure 3A the PRS module 342 in the UE 302 as shown in Figure 3C ; or at least one network interface 390; and at least one processor 394 having dedicated hardware or implementing executable code or software instructions in a memory 396, such as

[0240] Figures 10 to 13 Figure 14 shown in Figure 14 and in Stages 15 or 17 of Figure 3A ; or at least one network interface 390; and at least one processor 394 having dedicated hardware or implementing executable code or software instructions in a memory 396, such as Figure 3C the PRS module 398 in the network entity 306 as shown in

[0241] In a particular implementation, each anchor-to-anchor RxTx time difference measurement is a measurement performed by a mobile anchor entity based on the reception of a first PRS in a first set of PRS instances and the transmission of a second PRS in a second set of PRS instances, or is a measurement performed by a stationary anchor entity based on the reception of a third PRS in a second set of PRS instances and the transmission of a fourth PRS in a first set of PRS instances, for example as discussed in Figure 11 and Figure 12 and including Stages 6 and 9 as discussed in Figure 14 ; and

[0242] In a specific implementation, in the at least two anchor-to-anchor RxTx time difference measurements, the PRS from the first set of PRS instances and the corresponding PRS from the second set of PRS instances have the same RxTx timing error group identifier, for example, as discussed in Phase 2 of Figure 13 and Figure 14 as discussed.

[0243] In a specific implementation, the PRS transmitted by the stationary anchor entity associated with the at least two anchor-to-anchor RxTx time difference measurements in the first set of PRS instances has the same transmission timing error group identifier, for example, as discussed in Phase 2 of Figure 13 and Figure 14 as discussed.

[0244] In a specific implementation, the PRS transmitted by the mobile anchor entity associated with the at least two anchor-to-anchor RxTx time difference measurements in the second set of PRS instances has the same transmission timing error group identifier, for example, as discussed in Phase 2 of Figure 13 and Figure 14 as discussed.

[0245] In a specific implementation, the set of RSTD measurements for the target UE is triggered by a location server or by a stationary anchor entity, for example, as discussed in Phase 3 of Figure 13 and Figure 14 as discussed. For example, the set of RSTD measurements for the target UE can be triggered based on a location request from the target UE, for example, as discussed in Phase 3 of Figure 13 and Figure 14 as discussed. The trigger message sent to the target UE to trigger the set of RSTD measurements for the target UE can indicate the PRS resources in the first set of PRS instances and the second set of PRS instances, for example, as discussed in Phase 3 of Figure 13 and Figure 14 as discussed. The PRS resources in the first set of PRS instances and the second set of PRS instances can have the same periodicity, for example, as discussed in Phase 2 of Figure 13 and Figure 14 as discussed. The trigger message indicates the PRS resources in the first set of PRS instances for the at least two anchor-to-anchor RxTx time difference measurements, for example, as discussed in Phase 2 of Figure 13 and Figure 14 as discussed.

[0246] In a specific implementation, the positioning estimation entity is a location server, and the at least two anchor-to-anchor RxTx time difference measurements are received from one of the stationary anchor entity and the mobile anchor entity, for example, as discussed in Phases 13 and 17 of Figure 14 as discussed.

[0247] In a specific implementation, the positioning estimation entity is the target UE, and the at least two anchor-to-anchor RxTx time difference measurements are received from one of a stationary anchor entity and a mobile anchor entity, e.g., as Figure 14 discussed in phases 13 and 15 of

[0248] In a specific implementation, the PRSs in the second set of PRS instances transmitted by the mobile anchor entity for the set of RSTD measurements are reserved by the stationary anchor entity, e.g., as Figure 13 and Figure 14 discussed in phase 2 of

[0249] In a specific implementation, the PRSs in the second set of PRS instances transmitted by the mobile anchor entity for the set of RSTD measurements have a limit on the number of periods, e.g., as Figure 13 and Figure 14 discussed in phase 2 of

[0250] "An example", "an example", "certain examples", or "exemplary specific implementations" recited throughout this specification mean that a particular feature, structure, or characteristic described in connection with the feature and / or example can be included in at least one feature and / or example of the claimed subject matter. Thus, the phrases "in an example", "an example", "in certain examples", or "in certain specific implementations" or other similar phrases that appear throughout the specification do not necessarily refer to the same feature, example, and / or limitation. Furthermore, these particular features, structures, or characteristics may be combined in one or more examples and / or features.

[0251] Some portions of the detailed descriptions included herein are presented in the form of algorithms or symbolic representations of operations on binary digital signals stored within the memory of a specific apparatus or a dedicated computing device or platform. In the context of this particular specification, the term specific apparatus and the like includes a general-purpose computer that, once programmed, performs specific operations in accordance with instructions from program software. An algorithmic description or symbolic representation is an example of a technique used by those of ordinary skill in the signal processing or related arts to convey the substance of their work to others in the art. An algorithm herein is generally regarded as a self-consistent sequence of operations or the like that causes a desired result. In this context, an operation or process involves the physical manipulation of physical quantities. Typically, but not necessarily, such quantities may take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, or otherwise manipulated. For reasons of common usage, it has proven convenient at times to refer to such signals as bits, data, values, elements, symbols, characters, terms, numbers, numerical values, and the like. However, it should be understood that all such or similar terms are to be associated with the appropriate physical quantities and are merely convenient labels. Unless specifically stated otherwise, as will be apparent from the discussion herein, it should be appreciated that throughout this specification, discussions using terms such as "processing," "computing," "calculating," "determining," and the like refer to the actions or processes of a specific apparatus, such as a special-purpose computer, a dedicated computing device, or a similar dedicated electronic computing device. In the context of this specification, therefore, a special-purpose computer or a similar dedicated electronic computing device is capable of manipulating or transforming signals that are typically represented as physical electronic or magnetic quantities within the memory, registers, or other information storage devices, transmission devices, or display devices of that special-purpose computer or similar dedicated electronic computing device.

[0252] In the foregoing detailed description, numerous specific details are 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 may be practiced without these specific details. In other instances, methods and apparatuses known to those of ordinary skill in the art have not been described in detail so as not to obscure the claimed subject matter.

[0253] As used herein, the terms "and," "or," and "and / or" may include various meanings that also are, at least in part, dependent upon the context in which such terms are used. Generally, "or" when used in connection with a list, such as A, B, or C, is intended to mean A, B, and C (here used in an inclusive sense) as well as A, B, or C (here used in an exclusive sense). In addition, the term "one or more" as used herein may be used to describe any feature, structure, or characteristic in a singular form or may be used to describe plural features, structures, or characteristics or some other combination thereof. However, it should be noted that this is merely illustrative and the claimed subject matter is not limited to this example.

[0254] Although the presently 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. Additionally, many modifications can be made to adapt a particular scenario to the teachings of the claimed subject matter without departing from the central concepts described herein.

[0255] In view of this specification, the various embodiments can include different combinations of features. Examples of implementations are described in the following numbered clauses:

[0256] Clause 1. A method of operating a positioning estimation entity to determine the location of a target user equipment (UE), comprising: obtaining a set of reference signal time difference (RSTD) measurements for the target UE, the set of RSTD measurements including at least three RSTD measurements generated by the target UE at different times, wherein each RSTD measurement in the set of RSTD measurements is generated using a PRS from a first set of positioning reference signal (PRS) instances transmitted by a stationary anchor entity and a corresponding PRS from a second set of PRS instances transmitted by a mobile anchor entity; obtaining at least two anchor-to-anchor receive-transmit (RxTx) time difference measurements, wherein each anchor-to-anchor RxTx time difference measurement is associated with the PRS from the first set of PRS instances and the corresponding PRS from the second set of PRS instances, and wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements; and determining a positioning estimate for the target UE based on the set of RSTD measurements and the at least two anchor-to-anchor RxTx time difference measurements.

[0257] Clause 2. The method according to clause 1, wherein each anchor-to-anchor RxTx time difference measurement is a measurement performed by the mobile anchor entity based on reception of a first PRS in the first set of PRS instances and transmission of a second PRS in the second set of PRS instances, or is a measurement performed by the stationary anchor entity based on reception of a third PRS in the second set of PRS instances and transmission of a fourth PRS in the first set of PRS instances.

[0258] Clause 3. The method according to any one of clauses 1 to 2, wherein the PRS from the first set of PRS instances and the corresponding PRS from the second set of PRS instances in the at least two anchor-to-anchor RxTx time difference measurements have the same RxTx timing error group identifier.

[0259] Clause 4. The method according to any one of Clauses 1 to 3, wherein the PRS transmitted by the stationary anchor entity associated with the at least two anchor-to-anchor RxTx time difference measurements in the first set of PRS instances has the same transmission timing error group identifier.

[0260] Clause 5. The method according to any one of Clauses 1 to 4, wherein the PRS transmitted by the mobile anchor entity associated with the at least two anchor-to-anchor RxTx time difference measurements in the second set of PRS instances has the same transmission timing error group identifier.

[0261] Clause 6. The method according to any one of Clauses 1 to 5, wherein the set of RSTD measurements for the target UE is triggered by a location server or by the stationary anchor entity.

[0262] Clause 7. The method according to Clause 6, wherein the set of RSTD measurements for the target UE is triggered based on a location request from the target UE.

[0263] Clause 8. The method according to any one of Clauses 6 to 7, wherein the trigger message sent to the target UE to trigger the set of RSTD measurements for the target UE indicates the PRS resources in the first set of PRS instances and the second set of PRS instances.

[0264] Clause 9. The method according to Clause 8, wherein the PRS resources in the first set of PRS instances and the second set of PRS instances have the same periodicity.

[0265] Clause 10. The method according to any one of Clauses 6 to 9, wherein the trigger message indicates the PRS resources in the first set of PRS instances for the at least two anchor-to-anchor RxTx time difference measurements.

[0266] Clause 11. The method according to any one of Clauses 1 to 10, wherein the positioning estimation entity is a location server, and wherein the at least two anchor-to-anchor RxTx time difference measurements are received from one of the stationary anchor entity and the mobile anchor entity.

[0267] Clause 12. The method according to any one of Clauses 1 to 10, wherein the positioning 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 stationary anchor entity and the mobile anchor entity.

[0268] Clause 13. The method according to any one of Clauses 1 to 12, wherein the PRS in the set of second PRS instances transmitted by the mobile anchor entity for the set of RSTD measurements is reserved by the stationary anchor entity.

[0269] Clause 14. The method according to any one of Clauses 1 to 13, wherein the PRS in the set of second PRS instances transmitted by the mobile anchor entity for the set of RSTD measurements has a limit on the number of periods.

[0270] Clause 15. A positioning estimation entity configured to determine the positioning of a target user equipment (UE), the positioning estimation entity 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: obtain a set of reference signal time difference (RSTD) measurements for the target UE, the set of RSTD measurements including at least three RSTD measurements generated by the target UE at different times, wherein each RSTD measurement in the set of RSTD measurements is generated using a PRS from a set of first positioning reference signal (PRS) instances transmitted by a stationary anchor entity and a corresponding PRS from a set of second PRS instances transmitted by a mobile anchor entity; obtain at least two anchor-to-anchor receive-transmit (RxTx) time difference measurements, wherein each anchor-to-anchor RxTx time difference measurement is associated with the PRS from the set of first PRS instances and the corresponding PRS from the set of second PRS instances, and wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements; and determine a positioning estimate for the target UE based on the set of RSTD measurements and the at least two anchor-to-anchor RxTx time difference measurements.

[0271] Clause 16. The positioning estimation entity according to Clause 15, wherein each anchor-to-anchor RxTx time difference measurement is a measurement performed by the mobile anchor entity based on the reception of a first PRS in the set of first PRS instances and the transmission of a second PRS in the set of second PRS instances, or is a measurement performed by the stationary anchor entity based on the reception of a third PRS in the set of second PRS instances and the transmission of a fourth PRS in the set of first PRS instances.

[0272] Clause 17. The positioning estimation entity according to any one of Clauses 15 to 16, wherein the PRS from the set of first PRS instances and the corresponding PRS from the set of second PRS instances in the at least two anchor-to-anchor RxTx time difference measurements have the same RxTx timing error group identifier.

[0273] Clause 18. A positioning estimation entity according to any one of Clauses 15 to 17, wherein the PRS transmitted by the stationary anchor entity associated with the at least two anchor-to-anchor RxTx time difference measurements in the first set of PRS instances has the same transmission timing error group identifier.

[0274] Clause 19. A positioning estimation entity according to any one of Clauses 15 to 18, wherein the PRS transmitted by the mobile anchor entity associated with the at least two anchor-to-anchor RxTx time difference measurements in the second set of PRS instances has the same transmission timing error group identifier.

[0275] Clause 20. A positioning estimation entity according to any one of Clauses 15 to 19, wherein the set of RSTD measurements for the target UE is triggered by a location server or by the stationary anchor entity.

[0276] Clause 21. A positioning estimation entity according to Clause 20, wherein the set of RSTD measurements for the target UE is triggered based on a location request from the target UE.

[0277] Clause 22. A positioning estimation entity according to any one of Clauses 20 to 21, wherein a trigger message sent to the target UE to trigger the set of RSTD measurements for the target UE indicates the PRS resources in the first set of PRS instances and the second set of PRS instances.

[0278] Clause 23. A positioning estimation entity according to Clause 22, wherein the PRS resources in the first set of PRS instances and the second set of PRS instances have the same periodicity.

[0279] Clause 24. A positioning estimation entity according to any one of Clauses 20 to 23, wherein the trigger message indicates the PRS resources in the first set of PRS instances for the at least two anchor-to-anchor RxTx time difference measurements.

[0280] Clause 25. A positioning estimation entity according to any one of Clauses 15 to 24, wherein the positioning estimation entity is a location server, and wherein the at least one external interface includes at least one network interface, and the at least two anchor-to-anchor RxTx time difference measurements are received from one of the stationary anchor entity and the mobile anchor entity.

[0281] Clause 26. The positioning estimation entity according to any one of Clauses 15 to 24, wherein the positioning estimation entity is the target UE, and wherein the at least one external interface includes at least one wireless transceiver, and the at least two anchor-to-anchor RxTx time difference measurements are received from one of the stationary anchor entity and the mobile anchor entity.

[0282] Clause 27. The positioning estimation entity according to any one of Clauses 15 to 26, wherein the PRS in the second set of PRS instances transmitted by the mobile anchor entity for the set of RSTD measurements is reserved by the stationary anchor entity.

[0283] Clause 28. The positioning estimation entity according to any one of Clauses 15 to 27, wherein the PRS in the second set of PRS instances transmitted by the mobile anchor entity for the set of RSTD measurements has a limit on the number of periods.

[0284] Clause 29. A positioning estimation entity configured to determine the positioning of a target user equipment (UE), the positioning estimation entity comprising: means for obtaining a set of reference signal time difference (RSTD) measurements for the target UE, the set of RSTD measurements including at least three RSTD measurements generated by the target UE at different times, wherein each RSTD measurement in the set of RSTD measurements is generated using a PRS from a first set of positioning reference signal (PRS) instances transmitted by a stationary anchor entity and a corresponding PRS from a second set of PRS instances transmitted by a mobile anchor entity; means for obtaining at least two anchor-to-anchor receive-transmit (RxTx) time difference measurements, wherein each anchor-to-anchor RxTx time difference measurement is associated with the PRS from the first set of PRS instances and the corresponding PRS from the second set of PRS instances, and wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements; and means for determining a positioning estimate of the target UE based on the set of RSTD measurements and the at least two anchor-to-anchor RxTx time difference measurements.

[0285] Clause 30. The positioning estimation entity according to Clause 29, wherein each anchor-to-anchor RxTx time difference measurement is a measurement performed by the mobile anchor entity based on the reception of a first PRS in the first set of PRS instances and the transmission of a second PRS in the second set of PRS instances, or a measurement performed by the stationary anchor entity based on the reception of a third PRS in the second set of PRS instances and the transmission of a fourth PRS in the first set of PRS instances.

[0286] Clause 31. The positioning estimation entity according to any one of Clauses 29 to 30, wherein in the at least two anchor-to-anchor RxTx time difference measurements, the PRS from the first set of PRS instances and the corresponding PRS from the second set of PRS instances have the same RxTx timing error group identifier.

[0287] Clause 32. The positioning estimation entity according to any one of Clauses 29 to 31, wherein in the first set of PRS instances, the PRS transmitted by the stationary anchor entity associated with the at least two anchor-to-anchor RxTx time difference measurements has the same transmission timing error group identifier.

[0288] Clause 33. The positioning estimation entity according to any one of Clauses 29 to 32, wherein in the second set of PRS instances, the PRS transmitted by the mobile anchor entity associated with the at least two anchor-to-anchor RxTx time difference measurements has the same transmission timing error group identifier.

[0289] Clause 34. The positioning estimation entity according to any one of Clauses 29 to 33, wherein the set of RSTD measurements for the target UE is triggered by a location server or by the stationary anchor entity.

[0290] Clause 35. The positioning estimation entity according to Clause 34, wherein the set of RSTD measurements for the target UE is triggered based on a location request from the target UE.

[0291] Clause 36. The positioning estimation entity according to any one of Clauses 34 to 35, wherein the trigger message sent to the target UE to trigger the set of RSTD measurements for the target UE indicates the PRS resources in the first set of PRS instances and the second set of PRS instances.

[0292] Clause 37. The positioning estimation entity according to Clause 36, wherein the PRS resources in the first set of PRS instances and the second set of PRS instances have the same periodicity.

[0293] Clause 38. The positioning estimation entity according to any one of Clauses 34 to 37, wherein the trigger message indicates the PRS resources in the first set of PRS instances for the at least two anchor-to-anchor RxTx time difference measurements.

[0294] Clause 39. The positioning estimation entity according to any one of Clauses 29 to 38, wherein the positioning estimation entity is a location server, and wherein the at least two anchor-to-anchor RxTx time difference measurements are received from one of the stationary anchor entity and the mobile anchor entity.

[0295] Clause 40. A positioning estimation entity according to any one of Clauses 29 to 38, wherein the positioning 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 stationary anchor entity and the mobile anchor entity.

[0296] Clause 41. A positioning estimation entity according to any one of Clauses 29 to 40, wherein the PRS in the second set of PRS instances transmitted by the mobile anchor entity for the set of RSTD measurements is reserved by the stationary anchor entity.

[0297] Clause 42. A positioning estimation entity according to any one of Clauses 29 to 41, wherein the PRS in the second set of PRS instances transmitted by the mobile anchor entity for the set of RSTD measurements has a limit on the number of cycles.

[0298] Clause 43. A non-transitory storage medium having program code stored thereon, the program code being operable to configure at least one processor in a positioning estimation entity for determining the positioning of a target user equipment (UE), the program code including instructions for performing the following operations: obtaining a set of reference signal time difference (RSTD) measurements for the target UE, the set of RSTD measurements including at least three RSTD measurements generated by the target UE at different times, wherein each RSTD measurement in the set of RSTD measurements is generated using a PRS from a first set of positioning reference signal (PRS) instances transmitted by a stationary anchor entity and a corresponding PRS from a second set of PRS instances transmitted by a mobile anchor entity; obtaining at least two anchor-to-anchor receive transmit (RxTx) time difference measurements, wherein each anchor-to-anchor RxTx time difference measurement is associated with the PRS from the first set of PRS instances and the corresponding PRS from the second set of PRS instances, and wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements; and determining a positioning estimate for the target UE based on the set of RSTD measurements and the at least two anchor-to-anchor RxTx time difference measurements.

[0299] Clause 44. The non-transitory storage medium according to Clause 43, wherein each anchor-to-anchor RxTx time difference measurement is a measurement performed by the mobile anchor entity based on the reception of a first PRS in the first set of PRS instances and the transmission of a second PRS in the second set of PRS instances, or is a measurement performed by the stationary anchor entity based on the reception of a third PRS in the second set of PRS instances and the transmission of a fourth PRS in the first set of PRS instances.

[0300] Clause 45. The non-transitory storage medium according to any one of Clauses 43 to 44, wherein in the at least two anchor-to-anchor RxTx time difference measurements, the PRS from the first set of PRS instances and the corresponding PRS from the second set of PRS instances have the same RxTx timing error group identifier.

[0301] Clause 46. The non-transitory storage medium according to any one of Clauses 43 to 45, wherein the PRS transmitted by the stationary anchor entity associated with the at least two anchor-to-anchor RxTx time difference measurements in the first set of PRS instances has the same transmission timing error group identifier.

[0302] Clause 47. The non-transitory storage medium according to any one of Clauses 43 to 46, wherein the PRS transmitted by the mobile anchor entity associated with the at least two anchor-to-anchor RxTx time difference measurements in the second set of PRS instances has the same transmission timing error group identifier.

[0303] Clause 48. The non-transitory storage medium according to any one of Clauses 43 to 47, wherein the set of RSTD measurements for the target UE is triggered by a location server or by the stationary anchor entity.

[0304] Clause 49. The non-transitory storage medium according to Clause 48, wherein the set of RSTD measurements for the target UE is triggered based on a location request from the target UE.

[0305] Clause 50. The non-transitory storage medium according to any one of Clauses 48 to 49, wherein the trigger message sent to the target UE to trigger the set of RSTD measurements for the target UE indicates the PRS resources in the first set of PRS instances and the second set of PRS instances.

[0306] Clause 51. The non-transitory storage medium according to Clause 50, wherein the PRS resources in the first set of PRS instances and the second set of PRS instances have the same periodicity.

[0307] Clause 52. The non-transitory storage medium according to any one of Clauses 48 to 51, wherein the trigger message indicates the PRS resources in the first set of PRS instances for the at least two anchor-to-anchor RxTx time difference measurements.

[0308] Clause 53. The non-transitory storage medium according to any one of Clauses 43 to 52, wherein the positioning estimation entity is a location server, and wherein the at least two anchor-to-anchor RxTx time difference measurements are received from one of the stationary anchor entity and the mobile anchor entity.

[0309] Clause 54. The non-transitory storage medium according to any one of Clauses 43 to 52, wherein the positioning 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 stationary anchor entity and the mobile anchor entity.

[0310] Clause 55. The non-transitory storage medium according to any one of Clauses 43 to 54, wherein the PRS in the set of second PRS instances transmitted by the mobile anchor entity for the set of RSTD measurements is reserved by the stationary anchor entity.

[0311] Clause 56. The non-transitory storage medium according to any one of Clauses 43 to 55, wherein the PRS in the set of second PRS instances transmitted by the mobile anchor entity for the set of RSTD measurements has a limit on the number of periods.

[0312] Accordingly, the claimed subject matter is not intended to be limited to the specific examples disclosed, but the claimed subject matter may also include all aspects falling within the scope of the appended claims and their equivalents.

Claims

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

2. The method according to claim 1, wherein each anchor-to-anchor RxTx time difference measurement is a measurement performed by the mobile anchor entity based on reception of a first PRS in the first set of PRS instances and transmission of a second PRS in the second set of PRS instances, or is a measurement performed by the stationary anchor entity based on reception of a third PRS in the second set of PRS instances and transmission of a fourth PRS in the first set of PRS instances.

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

4. The method according to claim 1, wherein the PRS transmitted by the stationary anchor entity associated with the at least two anchor-to-anchor RxTx time difference measurements in the first set of PRS instances has the same transmit timing error group identifier.

5. The method according to claim 1, wherein the PRS transmitted by the mobile anchor entity associated with the at least two anchor-to-anchor RxTx time difference measurements in the second set of PRS instances has the same transmit timing error group identifier.

6. The method according to claim 1, wherein the set of RSTD measurements for the target UE is triggered by a location server or by the stationary anchor entity.

7. The method according to claim 6, wherein the set of RSTD measurements for the target UE is triggered based on a location request from the target UE.

8. The method according to claim 6, wherein a trigger message sent to the target UE to trigger the set of RSTD measurements for the target UE indicates the PRS resources in the first set of PRS instances and the second set of PRS instances.

9. The method according to claim 8, wherein the PRS resources in the first set of PRS instances and the second set of PRS instances have the same periodicity.

10. The method according to claim 6, wherein the trigger message indicates the PRS resources in the first set of PRS instances for the at least two anchor-to-anchor RxTx time difference measurements.

11. The method according to claim 1, wherein the positioning estimation entity is a location server, and wherein the at least two anchor-to-anchor RxTx time difference measurements are received from one of the stationary anchor entity and the mobile anchor entity.

12. The method according to claim 1, wherein the positioning 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 stationary anchor entity and the mobile anchor entity.

13. The method according to claim 1, wherein the PRS in the second set of PRS instances transmitted by the mobile anchor entity for the set of RSTD measurements is reserved by the stationary anchor entity.

14. The method according to claim 1, wherein the PRS in the second set of PRS instances transmitted by the mobile anchor entity for the set of RSTD measurements has a limit on the number of periods.

15. A positioning estimation entity configured to determine the positioning of a target user equipment (UE), the positioning estimation entity 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: obtain a set of reference signal time difference (RSTD) measurements for the target UE, the set of RSTD measurements including at least three RSTD measurements generated by the target UE at different times, wherein each RSTD measurement in the set of RSTD measurements is generated using the PRS from a first set of positioning reference signal (PRS) instances transmitted by a stationary anchor entity and the corresponding PRS from a second set of PRS instances transmitted by a mobile anchor entity; obtain at least two anchor-to-anchor receive transmit (RxTx) time difference measurements, wherein each anchor-to-anchor RxTx time difference measurement is associated with the PRS from the first set of PRS instances and the corresponding PRS from the second set of PRS instances, and wherein the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements; and determine a positioning estimate for the target UE based on the set of RSTD measurements and the at least two anchor-to-anchor RxTx time difference measurements.

16. The positioning estimation entity according to claim 15, wherein each anchor-to-anchor RxTx time difference measurement is a measurement performed by the mobile anchor entity based on the reception of the first PRS in the first PRS instance set and the transmission of the second PRS in the second PRS instance set, or is a measurement performed by the stationary anchor entity based on the reception of the third PRS in the second PRS instance set and the transmission of the fourth PRS in the first PRS instance set.

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

18. The positioning estimation entity according to claim 15, wherein the PRS transmitted by the stationary anchor entity associated with the at least two anchor-to-anchor RxTx time difference measurements in the first PRS instance set has the same transmission timing error group identifier.

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

20. The positioning estimation entity according to claim 15, wherein the set of RSTD measurements for the target UE is triggered by a location server or by the stationary anchor entity.

21. The positioning estimation entity according to claim 20, wherein the set of RSTD measurements for the target UE is triggered based on a location request from the target UE.

22. The positioning estimation entity according to claim 20, wherein the trigger message sent to the target UE to trigger the set of RSTD measurements for the target UE indicates the PRS resources in the first PRS instance set and the second PRS instance set.

23. The positioning estimation entity according to claim 22, wherein the PRS resources in the first PRS instance set and the second PRS instance set have the same periodicity.

24. The positioning estimation entity according to claim 20, wherein the trigger message indicates the PRS resources in the first PRS instance set for the at least two anchor-to-anchor RxTx time difference measurements.

25. The positioning estimation entity according to claim 15, wherein the positioning estimation entity is a location server, and wherein the at least one external interface includes at least one network interface, and the at least two anchor-to-anchor RxTx time difference measurements are received from one of the stationary anchor entity and the mobile anchor entity.

26. The positioning estimation entity according to claim 15, wherein the positioning estimation entity is the target UE, and wherein the at least one external interface includes at least one wireless transceiver, and the at least two anchor-to-anchor RxTx time difference measurements are received from one of the stationary anchor entity and the mobile anchor entity.

27. The positioning estimation entity according to claim 15, wherein the PRS in the second set of PRS instances transmitted by the mobile anchor entity for the set of RSTD measurements is reserved by the stationary anchor entity.

28. The positioning estimation entity according to claim 15, wherein the PRS in the second set of PRS instances transmitted by the mobile anchor entity for the set of RSTD measurements has a limit on the number of periods.

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

30. A non-transitory storage medium having program code stored thereon that is operative to configure at least one processor in a positioning estimation entity to determine the positioning of a target user equipment (UE), the program code including instructions for: obtaining a set of reference signal time difference (RSTD) measurements for the target UE, the set of RSTD measurements including at least three RSTD measurements generated by the target UE at different times, wherein each RSTD measurement in the set of RSTD measurements is generated using a PRS from a first set of positioning reference signal (PRS) instances transmitted by a stationary anchor entity and a corresponding PRS from a second set of PRS instances transmitted by a mobile anchor entity; Obtain at least two anchor-to-anchor receive transmit (RxTx) time difference measurements, where each anchor-to-anchor RxTx time difference measurement is associated with the PRS from the first set of PRS instances and the corresponding PRS from the second set of PRS instances, and where the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements; and Determine a positioning estimate for the target UE based on the set of RSTD measurements and the at least two anchor-to-anchor RxTx time difference measurements.

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