Position Estimation Method and Device Using a Mobile Anchor

Abstract

A location of a target user equipment (UE) is determined using a set of reference signal time difference (RSTD) measurements including at least three RSTD measurements generated at different times by the target UE. Each RSTD measurement is generated 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 inter-anchor transmit / receive (RxTx) time difference measurements are generated by the anchor entities, each inter-anchor RxTx time difference measurement is associated with an RSTD measurement, and there are fewer inter-anchor RxTx time difference measurements than the RSTD measurement. A location estimate of the target UE is determined based on the set of RSTD measurements and the at least two inter-anchor RxTx time difference measurements.

Description

[Technical Field]

[0001] BACKGROUND OF THE INVENTION

[0001] The subject matter disclosed herein relates generally to the field of wireless communications, and more particularly to techniques for supporting positioning. [Background technology]

[0002] Wireless communication systems have evolved through various generations, including first-generation analog wireless telephone service (1G), second-generation (2G) digital wireless telephone service (including interim 2.5G and 2.75G networks), third-generation (3G) high-speed data, Internet-enabled wireless service, and fourth-generation (4G) service (e.g., Long Term Evolution (LTE) or WiMax). Currently, many different types of wireless communication systems are in use, including cellular systems and personal communications service (PCS) systems. Examples of known cellular systems include the cellular analog advanced mobile phone system (AMPS) and digital cellular systems based on code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), Global System for Mobile communications (GSM), etc.

[0003]

[0003] The fifth-generation (5G) wireless standard, known as New Radio (NR), requires higher data rates, a larger number of connections, and better coverage, among other improvements. According to the Next Generation Mobile Network Alliance, the 5G standard is designed to provide data rates of tens of megabits per second to tens of thousands of users, providing 1 gigabit per second to a few dozen users on an office floor. To support large-scale deployment of sensors, hundreds of thousands of simultaneous connections must be supported. Therefore, the spectral efficiency of 5G mobile communications should be significantly increased compared to the current 4G standard. Furthermore, signaling efficiency must be increased and latency significantly reduced compared to current standards. Summary of the Invention

[0004] The location of a target user equipment (UE) is determined using a set of RSTD measurements including at least three Reference Signal Time Difference (RSTD) measurements generated by the target UE at different times. Each RSTD measurement is generated 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 inter-anchor receive-transmit (RxTx) time difference measurements are generated by the anchor entities, each inter-anchor RxTx time difference measurement is associated with an RSTD measurement, and there are fewer inter-anchor RxTx time difference measurements than RSTD measurements. A location estimate of the target UE is determined based on the set of RSTD measurements and the at least two inter-anchor RxTx time difference measurements.

[0005]

[0005] In one implementation, a method for operating a location estimation entity to determine a location of a target user equipment (UE) includes: obtaining a set of reference signal time difference (RSTD) measurements for the target UE, the set 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 positioning reference signal (PRS) instance set transmitted by a stationary anchor entity and a corresponding PRS from a second PRS instance set transmitted by a mobile anchor entity; obtaining at least two inter-anchor transmit / receive (RxTx) time difference measurements, wherein each inter-anchor RxTx time difference measurement is associated with a PRS from the first PRS instance set and a corresponding PRS from the second PRS instance set, and wherein the number of inter-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements; and determining a location estimate for the target UE based on the set of RSTD measurements and the at least two inter-anchor RxTx time difference measurements.

[0006] In one implementation, a location estimation entity configured to determine a location of a target user equipment (UE) includes a memory, at least one external interface, and at least one processor communicatively coupled to the memory and the at least one external interface, wherein the at least one processor is configured to generate 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 based on a PRS instance from a first PRS instance set transmitted by a stationary anchor entity and a PRS instance set transmitted by a mobile anchor entity. acquire a set of RSTD measurements generated using a PRS from the first PRS instance set and a corresponding PRS from a second PRS instance set that is transmitted to the anchor; acquire at least two inter-anchor transmit / receive (RxTx) time difference measurements, where each inter-anchor RxTx time difference measurement is associated with a PRS from the first PRS instance set and a corresponding PRS from the second PRS instance set, and the number of inter-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements; and determine a location estimate for the target UE based on the set of RSTD measurements and the at least two inter-anchor RxTx time difference measurements.

[0007]

[0007] In one implementation, a location estimation entity configured to determine a location of a target user equipment (UE) includes: means for acquiring a set of reference signal time difference (RSTD) measurements for the target UE, the set 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 positioning reference signal (PRS) instance set transmitted by a stationary anchor entity and a corresponding PRS from a second PRS instance set transmitted by a mobile anchor entity; means for acquiring at least two inter-anchor transmit / receive (RxTx) time difference measurements, wherein each inter-anchor RxTx time difference measurement is associated with a PRS from the first PRS instance set and a corresponding PRS from the second PRS instance set, and the number of inter-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements; and means for determining a location estimate for the target UE based on the set of RSTD measurements and the at least two inter-anchor RxTx time difference measurements.

[0008] In one implementation, a non-transitory storage medium including program code recorded thereon, the program code operable to configure at least one processor in a position estimation entity to determine a position of a target user equipment (UE), the program being instructions for: a set of reference signal time difference (RSTD) measurements for the target UE including at least three RSTD measurements generated by the target UE at different times, each RSTD measurement in the set of RSTD measurements being a PRS from a first set of positioning reference signal (PRS) instances transmitted by a stationary anchor entity and a second PRS transmitted by a mobile anchor entity; and a corresponding PRS from a first PRS instance set; acquire at least two inter-anchor transmit / receive (RxTx) time difference measurements, wherein each inter-anchor RxTx time difference measurement is associated with a PRS from a first PRS instance set and a corresponding PRS from a second PRS instance set, and the number of inter-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements; and determine a location estimate for the target UE based on the set of RSTD measurements and the at least two inter-anchor RxTx time difference measurements. [Brief explanation of the drawings]

[0009]

[0009] The accompanying drawings are presented to aid in the explanation of various aspects of the present disclosure and are provided only to illustrate the aspects, not to limit the aspects. [Figure 1A]

[0010] 1 illustrates an exemplary wireless communication system according to an aspect of the present disclosure. [Figure 1B]

[0011] FIG. 1A shows an architectural diagram of a possible base station node. [Figure 2A]

[0012] 1 illustrates an exemplary wireless network structure according to aspects of the present disclosure. [Figure 2B]1 illustrates an exemplary wireless network structure according to aspects of the present disclosure. [Figure 3A]

[0013] FIG. 1 is a simplified block diagram of several sample aspects of components that may be employed within a user equipment (UE), a base station, and a network entity and configured to support communication as taught herein. [Figure 3B] FIG. 1 is a simplified block diagram of several sample aspects of components that may be employed within a user equipment (UE), a base station, and a network entity and configured to support communication as taught herein. [Figure 3C] FIG. 1 is a simplified block diagram of several sample aspects of components that may be employed within a user equipment (UE), a base station, and a network entity and configured to support communication as taught herein. [Figure 4A]

[0014] FIG. 2 illustrates an example frame structure and channels within the frame structure, according to aspects of the present disclosure. [Figure 4B] FIG. 2 illustrates an example frame structure and channels within the frame structure, according to aspects of the present disclosure. [Figure 4C] FIG. 2 illustrates an example frame structure and channels within the frame structure, according to aspects of the present disclosure. [Figure 4D] FIG. 2 illustrates an example frame structure and channels within the frame structure, according to aspects of the present disclosure. [Figure 5]

[0015] 1 is a diagram of example positioning reference signal (PRS) resource sets with different time gaps, according to an aspect of the disclosure. [Figure 6]

[0016] 1 illustrates an example of conventional downlink (DL) time difference of arrival (TDoA) based positioning. [Figure 7]

[0017] 1 illustrates an example of conventional uplink (UL) TDoA-based positioning. [Figure 8]

[0018] 1 shows a timing diagram of TDOA measurement signals exchanged between a UE and a stationary anchor. [Figure 9]

[0019] 10 shows a timing diagram of TDOA measurement signals exchanged between a UE and a stationary anchor with improved accuracy. [Figure 10]

[0020] 1 illustrates a wireless communication system including a mobile anchor that may be used in TDOA measurements. [Figure 11]

[0021] 10 shows a timing diagram of TDOA measurement signals exchanged between a UE and stationary and mobile anchors with improved accuracy. [Figure 12]

[0022] 10 shows another timing diagram of TDOA measurement signals exchanged between a UE and stationary and mobile anchors with improved accuracy. [Figure 13]

[0023] The PRS transmitted by the stationary and mobile anchors are shown to generate measurement sets for improved accuracy. [Figure 14]

[0024] 10 is a message flow illustrating messaging between a location server target UE and stationary and mobile anchors to support measurements for improved accuracy. [Figure 15]

[0025] 1 illustrates a flowchart of an example process disclosed herein for supporting the operation of a location estimation entity to determine the location of a target UE. DETAILED DESCRIPTION OF THE INVENTION

[0010]

[0026] Aspects of the present disclosure are provided in the following description and related drawings, directed to various examples provided for illustrative purposes. Alternative aspects may be devised 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.

[0011]

[0027] The words "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 advantageous over other aspects. Likewise, 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.

[0012]

[0028] Those skilled in the art will understand that the information and signals described below may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the following description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof, depending in part on the particular application, desired design, corresponding technology, etc.

[0013]

[0029] Further, many aspects are described in terms of sequences of actions to be performed by, for example, elements of a computing device. It will be appreciated that various activities described herein may be performed by particular circuitry (e.g., an application specific integrated circuit (ASIC)), by program instructions executed by one or more processors, or a combination of both. In addition, a sequence of actions described herein may be considered to be embodied entirely in any form of non-transitory computer-readable storage medium storing a corresponding set of computer instructions, which, when executed, cause or instruct associated processors of a device to perform the functions described herein. Accordingly, various aspects of the present disclosure may be embodied in several different forms, all of which are contemplated to be within the scope of the claimed subject matter. Additionally, for each aspect described herein, the corresponding form of any such aspect may be described herein, for example, as “logic configured to” perform the described actions.

[0014]

[0030] The terms “user equipment” (UE) and “base station,” as used herein, are not intended to be specific to or otherwise limited to any particular radio access technology (RAT) unless otherwise specified. Generally, a UE may be any wireless communication device (e.g., a mobile phone, a router, a tablet computer, a laptop computer, a consumer location device, a wearable (e.g., a smart watch, glasses, augmented reality (AR) / virtual reality (VR) headset, etc.), a vehicle (e.g., a car, a motorcycle, a bicycle, etc.), an Internet of Things (IoT) device, etc.) used by a user to communicate over a wireless communication network. A UE may be mobile or stationary (e.g., at a given time) and may communicate with a radio access network (RAN). As used herein, the term “UE” may be referred to interchangeably as an “access terminal” or “AT,” a “client device,” a “wireless device,” a “subscriber device,” a “subscriber terminal,” a “subscriber station,” a “user terminal” or “UT,” a “mobile device,” a “mobile terminal,” a “mobile station,” or variations thereof. Generally, a UE can communicate with a core network via a RAN, through which the UE can be connected to external networks such as the Internet and to other UEs. Of course, other mechanisms for connecting to the core network and / or the Internet are also possible for a UE, such as via a wired access network, a wireless local area network (WLAN) network (e.g., based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 specification, etc.), etc.

[0015]

[0031] A base station may operate according to one of several RATs with which it communicates with UEs depending on the network in which it is deployed and may alternatively be referred to as an access point (AP), network node, Node B, evolved Node B (eNB), next generation eNB (ng-eNB), new radio (NR) Node B (also referred to as gNB or gNode B), etc. A base station may be used primarily to support wireless access by UEs, including supporting data, voice, and / or signaling connections for supported UEs. In some systems, a base station may provide only edge node signaling functionality, while in other systems, a base station may provide additional control and / or network management functionality. A communication link through which a UE can send signals to a base station is called an uplink (UL) channel (e.g., a reverse traffic channel, a reverse control channel, an access channel, etc.). A communication link through which a base station can send signals to a UE is called a downlink (DL) or forward link channel (e.g., a paging channel, a control channel, a broadcast channel, a forward traffic channel, etc.). As used herein, the term traffic channel (TCH) can refer to either an uplink / reverse traffic channel or a downlink / forward traffic channel. In addition, a communication link over which a UE can send signals to other UEs is called a sidelink (SL) channel.

[0016]

[0032] The term "base station" can refer to a single physical transmission / reception point (TRP) or multiple physical TRPs, which may or may not be collocated. For example, when the term "base station" refers to a single physical TRP, the physical TRP may be an antenna of the base station corresponding to the base station's cell (or several cell sectors). When the term "base station" refers to multiple collocated physical TRPs, the physical TRP may be an array of antennas of the base station (e.g., as in a multiple-input multiple-output (MIMO) system or when the base station employs beamforming). When the term "base station" refers to multiple non-collocated physical TRPs, the physical TRP may be a distributed antenna system (DAS) (a network of spatially separated antennas connected to a common source via a transport medium) or a remote radio head (RRH) (a remote base station connected to a serving base station). Alternatively, non-co-located physical TRPs may be the serving base station that receives measurement reports from the UE and neighboring base stations whose reference radio frequency (RF) signals the UE is measuring. Because a TRP is a point from which a base station transmits and receives wireless signals, as used herein, references to transmission from or reception at a base station should be understood as referring to a particular TRP of the base station.

[0017]

[0033] In some implementations that support UE positioning, a base station may not support wireless access by the UE (e.g., may not support a data connection, a voice connection, and / or a signaling connection for the UE), but may instead transmit reference signals to the UE to be measured by the UE and / or receive and measure signals transmitted by the UE. Such a base station may be referred to as a positioning beacon (e.g., when transmitting signals to the UE) and / or a location measurement unit (e.g., when receiving and measuring signals from the UE).

[0018]

[0034] An "RF signal" includes electromagnetic waves of a given frequency that propagate information through space between a transmitter and a receiver. As used herein, a transmitter may transmit a single "RF signal" or multiple "RF signals" to a receiver. However, due to the propagation characteristics of RF signals through multipath channels, the receiver may receive multiple "RF signals" corresponding to each transmitted RF signal. The same RF signal transmitted over different paths between the transmitter and receiver is sometimes referred to as a "multipath" RF signal.

[0019]

[0035] 1A illustrates an exemplary wireless communication system 100 according to an aspect of the present disclosure. The wireless communication system 100 (sometimes referred to as a wireless wide area network (WWAN)) may include various base stations 102 (labeled “BS”) and various UEs 104. The base stations 102 may include macrocell base stations (high-power cellular base stations) and / or small cell base stations (low-power cellular base stations). In an aspect, the macrocell base stations may include eNBs and / or ng-eNBs where the wireless communication system 100 corresponds to an LTE network, or gNBs where the wireless communication system 100 corresponds to an NR network, or a combination of both, and the small cell base stations may include femtocells, picocells, microcells, etc.

[0020]

[0036] The base stations 102 may collectively form a RAN and may interface with a core network 170 (e.g., evolved packet core (EPC) or 5G core (5G core, 5GC)) through backhaul links 122 and to one or more location servers 172 (e.g., a location management function (LMF) or a secure user plane location (SUPL) location platform (SLP)) through the core network 170. The location servers 172 may be part of the core network 170 or may be external to the core network 170. In addition to other functions, the base stations 102 may perform functions related to one or more of the following: forwarding user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, non-access stratum (NAS) message delivery, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment tracing, RAN information management (RIM), paging, positioning, and alert message delivery. The base stations 102 may communicate with each other directly or indirectly (e.g., through EPC / 5GC) via backhaul links 134, which may be wired or wireless.

[0021]

[0037] The base stations 102 may wirelessly communicate with the UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. In an aspect, one or more cells may be supported by the base stations 102 within each geographic coverage area 110. A “cell” is a logical communication entity used for communication with a base station (e.g., over some frequency resources referred to as a carrier frequency, component carrier, carrier, band, etc.) and may be associated with an identifier (e.g., a physical cell identifier (PCI), an enhanced cell identifier (ECI), a virtual cell identifier (VCI), a cell global identifier (CGI), etc.) to distinguish between cells operating over the same or different carrier frequencies. In some cases, different cells may be configured according to different protocol types (e.g., machine-type communication (MTC), narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB), or others) that may provide access for different types of UEs. Because a cell is supported by a particular base station, the term "cell" can refer to either or both of a logical communication entity and the base station that supports it, depending on the context. In some cases, the term "cell" can also refer to the geographic coverage area (e.g., sector) of a base station, so long as a carrier frequency can be detected and used for communication within some portion of the geographic coverage area 110.

[0022]

[0038] The geographic coverage areas 110 of neighboring macrocell base stations 102 may partially overlap (e.g., in handover regions), and some of the geographic coverage areas 110 may be substantially overlapped by larger geographic coverage areas 110. For example, a small cell base station 102' (labeled "SC" for "small cell") may have a geographic coverage area 110' that significantly overlaps with the geographic coverage area 110 of one or more macrocell base stations 102. A network including both small cell and macrocell base stations may be known as a heterogeneous network. A heterogeneous network may also include home eNBs (HeNBs), which may serve closed groups known as closed subscriber groups (CSGs).

[0023]

[0039] The communication link 120 between the base station 102 and the UE 104 may include uplink (also referred to as reverse link) transmissions from the UE 104 to the base station 102 and / or downlink (DL) (also referred to as forward link) transmissions from the base station 102 to the UE 104. The communication link 120 may further include a sidelink channel 120′ that may be used to directly connect multiple UEs 104, e.g., denoted UEs 104′ in FIG. 1A. The communication link 120 may use MIMO antenna techniques, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link 120 may be over one or more carrier frequencies. Carrier allocation may be asymmetric with respect to the downlink and uplink (e.g., more or fewer carriers may be allocated for the downlink than for the uplink).

[0024]

[0040] The wireless communication system 100 may further include a wireless local area network (WLAN) access point (WLAN) 150 communicating with a WLAN station (STA) 152 via a communication link 154 in an unlicensed frequency spectrum (e.g., 5 GHz). When communicating in the unlicensed frequency spectrum, the WLAN STA 152 and / or the WLAN AP 150 may perform a clear channel assessment (CCA) or listen before talk (LBT) procedure before communicating to determine whether a channel is available.

[0025]

[0041] The small cell base station 102' may operate in licensed and / or unlicensed frequency spectrum. When operating in the unlicensed frequency spectrum, the small cell base station 102' may utilize LTE or NR technology and use the same 5 GHz unlicensed frequency spectrum used by the WLAN AP 150. A small cell base station 102' employing LTE / 5G in the unlicensed frequency spectrum may extend coverage to and / or increase the capacity of the access network. NR in the unlicensed spectrum may be referred to as NR-U. LTE in the unlicensed spectrum may be referred to as LTE-U, licensed assisted access (LAA), or MultiFire.

[0026]

[0042] The wireless communication system 100 may further include an mmW base station 180 that may operate within millimeter wave (mmW) and / or sub-mmW frequencies in communication with the UE 182. Extremely high frequency (EHF) is a portion of RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength of 1 millimeter to 10 millimeters. Radio waves in this band are sometimes referred to as millimeter waves. Sub-mmW may extend down to frequencies of 3 GHz with wavelengths of 100 millimeters. The super high frequency (SHF) band extends from 3 GHz to 30 GHz and is also referred to as centimeter waves. Communications using the mmW / sub-mmW radio frequency bands have high path loss and relatively short distances. The mmW base station 180 and the UE 182 may utilize beamforming (transmit and / or receive) over the mmW communication link 184 to compensate for the extremely high path loss and short distances. It will be further understood that in alternative configurations, one or more base stations 102 may also transmit using mmW or quasi-mmW and beamforming. Accordingly, it will be understood that the above illustrations are merely examples and should not be construed as limiting various aspects disclosed herein.

[0027]

[0043] Transmit beamforming is a technique for focusing an RF signal in a particular direction. Traditionally, when a network node (e.g., a base station) broadcasts an RF signal, it broadcasts that signal in all directions (omnidirectionally). 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 emits a stronger downlink RF signal in that particular direction, thereby providing a faster and more powerful RF signal (in terms of data rate) to the receiving device. To change the directionality of the RF signal when transmitting, the network node can control the phase and relative amplitude of the RF signal at each of one or more transmitters broadcasting the RF signal. For example, the network node may use an array of antennas (also called a "phased array" or "antenna array") that creates beams of RF waves that can be "steered" to point in different directions without actually moving the antennas. Specifically, RF currents from the transmitters are supplied to individual antennas with the appropriate phase relationship so that radio waves from separate antennas combine together to enhance radiation in desired directions while canceling out radiation in undesired directions.

[0028]

[0044] A transmit beam may be quasi-colocated, meaning that the transmit beam appears to a receiver (e.g., a UE) to have the same parameters regardless of whether the network node's own transmit antenna is physically colocated. In NR, there are four types of quasi-colocation (QCL) relationships. Specifically, a given type of QCL relationship means that some parameters for a second reference RF signal on a second beam can be derived from information about a source reference RF signal on a source beam. Thus, if the source reference RF signal is QCL Type A, the receiver can use the source reference RF signal to estimate the Doppler shift, Doppler spread, mean 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 spatial reception parameters of a second reference RF signal transmitted on the same channel.

[0029]

[0045] In receive beamforming, a receiver uses receive beams to amplify RF signals detected on a given channel. For example, the receiver can increase the gain setting and / or adjust the phase setting of an antenna array in a particular direction to amplify (e.g., increase the gain level of) RF signals received from that direction. Thus, when a receiver is said to beamform in a direction, it means that the beam gain in that direction is higher than the beam gains along other directions, or that the beam gain in that direction is 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 (e.g., reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-interference-plus-noise ratio (SINR), etc.) of RF signals received from that direction.

[0030]

[0046] The transmit beam and the receive beam may be spatially related. A spatial relationship means that parameters for a second beam (e.g., a transmit beam or a receive beam) for a second reference signal may be derived from information about a first beam (e.g., a receive beam or a transmit beam) for a first reference signal. For example, a UE may use a particular receive beam to receive a reference downlink reference signal (e.g., a synchronization signal block (SSB)) from a base station. The UE can then form a transmit beam for sending an uplink reference signal (e.g., a sounding reference signal (SRS)) to that base station based on the parameters of the receive beam.

[0031]

[0047] Note that a "downlink" beam can be either a transmit beam or a receive beam, depending on the entity that forms it. For example, if a base station forms a downlink beam to transmit a reference signal to a UE, the downlink beam is a transmit beam. However, if the UE forms a downlink beam, it is a receive beam to receive a downlink reference signal. Similarly, an "uplink" beam can be either a transmit beam or a receive beam, depending on the entity that forms it. For example, if a base station forms an uplink beam, it is an uplink receive beam, and if the UE forms an uplink beam, it is an uplink transmit beam.

[0032]

[0048] In 5G, the frequency spectrum in which wireless nodes (e.g., base stations 102 / 180, UEs 104 / 182) operate is divided into multiple frequency ranges: FR1 (450-6000 MHz), FR2 (24250-52600 MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). The mmW frequency band generally includes the FR2, FR3, and FR4 frequency ranges. Thus, the terms "mmW" and "FR2" or "FR3" or "FR4" may generally be used interchangeably.

[0033]

[0049] 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 the carrier operating on the primary frequency (e.g., FR1) utilized by the UE 104 / 182 and on the cell where the UE 104 / 182 either performs an initial radio resource control (RRC) connection establishment procedure or initiates an RRC connection re-establishment procedure. The primary carrier carries all common control channels and UE-specific control channels and may (but is not always) be a carrier among licensed frequencies. The secondary carrier is a carrier operating on a second frequency (e.g., FR2) that may be configured once an RRC connection is established between the UE 104 and the anchor carrier and may be used to provide additional radio resources. In some cases, the secondary carrier may be a carrier among unlicensed frequencies. Since both the primary uplink carrier and the primary downlink carrier are typically UE-specific, the secondary carrier may contain only the necessary signaling information and signals; e.g., UE-specific signaling information and signals may not be present in the secondary carrier. This means that different UEs 104 / 182 in a cell may have different downlink primary carriers. The same applies to the uplink primary carrier. The network can change the primary carrier of any UE 104 / 182 at any time. This is done, for example, to balance the load on different carriers. Since a "serving cell" (whether PCell or SCell) corresponds to a carrier frequency / component carrier over which several base stations are communicating, terms such as "cell," "serving cell," "component carrier," and "carrier frequency" may be used interchangeably.

[0034]

[0050] 1A, one of the frequencies utilized by the macrocell base station 102 may be an anchor carrier (or "PCell"), and other frequencies utilized by the macrocell base station 102 and / or the mmW base station 180 may be secondary carriers ("SCells"). Simultaneous transmission and / or reception of multiple carriers allows the UE 104 / 182 to significantly increase its data transmission and / or reception rates. For example, two 20 MHz carriers aggregated in a multi-carrier system would theoretically lead to a two-fold increase in data rate (i.e., 40 MHz) compared to the data rate achieved by a single 20 MHz carrier.

[0035]

[0051] Wireless communications system 100 may further include a UE 164 that may communicate with macrocell base station 102 via communications link 120 and / or with mmW base station 180 via mmW communications link 184. For example, macrocell base station 102 may support a PCell and one or more SCells for UE 164, and mmW base station 180 may support one or more SCells for UE 164.

[0036]

[0052] In the example of FIG. 1A , one or more Earth-orbiting satellite positioning system (SPS) space vehicles (SVs) 112 (e.g., satellites) may be used as independent sources of location information for any of the depicted UEs (shown in FIG. 1A as a single UE 104 for simplicity). The UE 104 may include one or more dedicated SPS receivers specifically designed to receive SPS signals 124 to derive geolocation information from the SVs 112. An SPS typically includes a system of transmitters (e.g., SVs 112) positioned to enable receivers (e.g., UEs 104) to determine their location on or above the Earth based, at least in part, on signals received from the transmitters (e.g., SPS signals 124). Such transmitters typically transmit signals marked with a repeating pseudo-random noise (PN) code with a set number of chips. While typically located within the SVs 112, transmitters may sometimes be located on ground-based control stations, base stations 102, and / or other UEs 104.

[0037]

[0053] Use of SPS signals 124 may be augmented by various satellite-based augmentation systems (SBAS) that may be associated with or otherwise enabled for use with one or more global and / or regional navigation satellite systems. For example, SBAS may include augmentation systems that provide integrity information, differential corrections, and the like, such as the Wide Area Augmentation System (WAAS), the European Geostationary Navigation Overlay Service (EGNOS), the Multi-functional Satellite Augmentation System (MSAS), the Global Positioning System (GPS)-aided Geo-Augmented Navigation, or the GPS and Geo Augmented Navigation system (GAGAN). Thus, as used herein, SPS may include any combination of one or more global and / or regional navigation satellite systems and / or augmentation systems, and SPS signals 124 may include SPSs, SPS-like signals, and / or other signals associated with such one or more SPSs.

[0038]

[0054] The wireless communication system 100 may further include one or more UEs, such as a UE 190, that indirectly connect to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links (referred to as “sidelinks”). In the example of FIG. 1A , the UE 190 has a D2D P2P link 192 with one of the UEs 104 connected to one of the base stations 102 (e.g., through which the UE 190 may indirectly obtain cellular connectivity) and a D2D P2P link 194 with a WLAN STA 152 connected to a WLAN AP 150 (through which the UE 190 may indirectly obtain WLAN-based Internet connectivity). In an example, the D2D P2P links 192 and 194 may be supported using any well-known D2D RAT, such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), Bluetooth®, etc.

[0039]

[0055] 1B shows an architectural diagram of an NG-RAN node, e.g., a base station 102, that may be in the NG-RAN in FIG. 1A, e.g., as a separate entity or as part of another gNB. The base station 102 may be a gNB 109, according to one implementation. The architecture shown in FIG. 1B may be applicable to, for example, any of the gNBs 109 in FIG. 1A.

[0040]

[0056] As shown, the 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 within the gNB 109 or may be physically separate. The gNB-CU 103 is a logical or physical node that hosts the gNB 109's Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), and Packet Data Convergence Protocol (PDCP) protocol support, which are used over the NR Uu air interface and control 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 implementations, the F1 interface connected to the gNB-RU. As shown, the gNB-CU 103 may communicate with the AMF via an NG interface. The gNB-CU 103 may further communicate with one or more other gNBs 109 via an Xn interface. The gNB-DU 105-DU is a logical or physical node that hosts support for the Radio Link Control (RLC), Medium Access Control (MAC), and Physical (PHY) protocol layers used on the NR Uu air interface of the gNB 109, and its operation is controlled in part by the gNB-CU 103. The gNB-DU terminates the F1 interface connected to the gNB-CU 103 and may terminate a lower layer split point interface Fx with the gNB-RU.The gNB-RU105-RU may be based on a lower layer function split and is a logical or physical node that hosts support for lower layer functions, such as the PHY and radio frequency (RF) protocol layers used over the NR Uu air interface of the gNB109, and its operation is controlled in part by the gNB-CU103 and / or gNB-DU105-DU. The gNB-RU105-RU terminates the Fx interface connected to the gNB-DU105-DU, and in some implementations may terminate the F1 interface connected to the gNB-CU103.

[0041]

[0057] The gNB-CU103 requests positioning measurements (e.g., E-CID) from the gNB-DU105-DU and / or gNB-RU105-RU. The gNB-DU105-DU and / or gNB-RU105-RU may report the measurements back to the gNB-CU103. The gNB-DU105-DU or gNB-RU105-RU may include positioning measurement functionality. It should be understood that other measurement nodes are not excluded.

[0042]

[0058] 1B, the gNB 109 may include a Transmission Point (TP) 107 and a Reception Point (RP) 108 combined into a Transmission Reception Point (TRP) 106, which may be physically or logically located within the gNB 109. The gNB-CU 103 may be configured to communicate with the TP 107 and the RP 108, for example, via an F1 interface. Thus, the gNB-CU 103 controls one or more TPs 107 and RPs 108 that are accessible to the gNB-CU 103 via the F1 interface.

[0043]

[0059] In some embodiments, the base station 102 (or gNB 109) may comprise a subset of the elements shown in FIG. 1B. For example, the NG-RAN node 102 may comprise the gNB-CU 103 but may not include one or more of the gNB-DU 105-DU and gNB-RU 105-RU, the RP 108, or the TP 107. Alternatively, the base station 102 may include the gNB-DU 105-DU and one or more of the RP 108 or the TP 107 but may not include the gNB-RU 105-RU. Furthermore, the elements shown in FIG. 1B may be logically separate but physically co-located, or may be partially or completely physically separate. For example, the gNB-DU 105-DU and / or one or more of the gNB-RU 105-RU, the RP 108, or the TP 107 may be physically separate from the gNB-CU 103 or may be physically combined with the gNB-CU 103. In the case of physical separation, an F1 interface or Fx interface may define the signaling over the physical link or connection between the two separated elements. In some implementations, the gNB-CU 103 may be split into a control plane portion (referred to as CU-CP or gNB-CU-CP) and a user plane portion (referred to as CU-UP or gNB-CU-UP). In this case, both the gNB-CU-CP and gNB-CU-UP may interact with the 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 the gNB-CU-CP may interact with the TP 107 and RP 108 to support and control location-related communications.

[0044]

[0060] The protocol layering between the gNB-CU 103 and the TP 107 and between the 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 level as specified in 3GPP TS 38.473. New messages to support positioning may be added directly to the F1AP or may be introduced in a new location-specific protocol that is transported using the F1AP.

[0045]

[0061] Location procedures with the gNB-CU 103 may comprise all location-related procedures over the NG interface, the Xn interface, and the NR-Uu interface. For example, location procedures between the AMF and the base station 102 may use NGAP. Location procedures between the base station 102 and other NG-RAN nodes, such as the gNB 109, may use XnAP or a protocol above XnAP, such as the enhanced NR Positioning Protocol A (NRPPa) as defined in 3GPP TS38.455. Location procedures between the base station 102 and the UE 104 may use RRC and / or LPP.

[0046]

[0062] Corresponding messages to support positioning may be carried inside a transparent F1AP message transport container. For example, NGAP location reporting control and NAS transport message transports may be carried in UL / DL NGAP message transports, location related XnAP message transports may be carried in UL / DL XnAP message transfers, and location related RRC (LPP) message transports may be carried in UL / DL RRC (LPP) message transports.

[0047]

[0063] 2A illustrates an exemplary wireless network structure 200. For example, a 5GC 210 (also referred to as a Next Generation Core (NGC)) may be functionally viewed as control plane (C-plane) functions 214 (e.g., UE registration, authentication, network access, gateway selection, etc.) and user plane (U-plane) functions 212 (e.g., UE gateway functionality, data network access, IP routing, etc.) that operate cooperatively to form a core network. A user plane interface (NG-U) 213 and a control plane interface (NG-C) 215 connect a gNB 222 to the 5GC 210, specifically to the user plane function 212 and the control plane function 214, respectively. In additional configurations, an 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. Additionally, 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 both 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).

[0048]

[0064] Another optional aspect may include one or more location servers 230a, 230b (sometimes collectively referred to as location servers 230) (which may correspond to location server 172), which may be in communication with the control plane function 214 and user plane function 212, respectively, in the 5GC 210 to provide location assistance to the UE 204. The location servers 230 may be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules across multiple physical servers, etc.), or alternatively, may each correspond to a single server. The location servers 230 may be configured to support one or more location services for UEs 204 that can connect to the location server 230 via the core network, the 5GC 210, and / or via the Internet (not shown). Furthermore, 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).

[0049]

[0065] 2B illustrates another exemplary wireless network structure 250. For example, a 5GC 260 (also referred to as an "NGC") may be functionally viewed as the control plane functions provided by an 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 operate in conjunction to form a core network (i.e., 5GC 260). A user plane interface 263 and a 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, eNB 224 may communicate directly with gNB 222 via backhaul connection 223, with or without a gNB direct connection to 5GC 260. In some configurations, new RAN 220 may have only one or more gNBs 222, while other configurations include one or more of both ng-eNB 224 and gNB 222. Either gNB 222 or eNB 224 may communicate with UE 204 (e.g., any of the UEs shown in FIG. 1A). Base stations of new RAN 220 communicate with AMF 264 via the N2 interface and with UPF 262 via the N3 interface.

[0050]

[0066] The AMF functions include registration management, connection management, reachability management, mobility management, lawful interception, transport of session management (SM) messages between the UE 204 and the SMF 266, a transparent proxy service for routing SM messages, access authentication and authorization, transport of short message service (SMS) messages between the UE 204 and a short message service function (SMSF) (not shown), and a security anchor functionality (SEAF). The AMF also interacts with an authentication server function (AUSF) (not shown) and the UE 204 to receive intermediate keys established as a result of the UE 204 authentication process. In the case of authentication based on a Universal Mobile Telecommunications System (UMTS) subscriber identity module (USIM), the AMF retrieves security material from the AUSF. The AMF's functions also include security context management (SCM), which receives keys from the SEAF that the SCM uses to derive access network specific keys. The functions of the AMF also include location service management for barred services, transport of location service messages 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 an evolved packet system (EPS), and UE 204 mobility event notification. In addition, the AMF also supports functionality for non-Third Generation Partnership Project (3GPP) access networks.

[0051]

[0067] The functions of the UPF include acting as an anchor point for intra / inter-RAT mobility (when applicable), acting as an external protocol data unit (PDU) session point for interconnection to a data network (not shown), packet routing and forwarding, packet inspection, user plane policy rule enforcement (e.g., gating, redirection, traffic steering), lawful interception (user plane collection), traffic usage reporting, quality of service (QoS) processing for the user plane (e.g., UL / DL rate enforcement, reflective QoS marking in DL), UL traffic validation (service data flow (SDF) to QoS flow mapping), transport-level packet marking in UL and DL, DL packet buffering and DL data notification triggering, and providing delivery and forwarding of one or more "end markers" to the source RAN node.

[0052]

[0068] The functions of the SMF 266 include session management, UE Internet protocol (IP) address allocation and management, user plane function selection and control, configuration of traffic steering in the UPF to route traffic to the appropriate destination, policy enforcement and part of the control of QoS, and downlink data notification. The interface through which the SMF 266 communicates with the AMF 264 is called the N11 interface.

[0053]

[0069] Another optional aspect may include an LMF 270, which may be in communication with the 5GC 260, to provide location assistance to 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 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 UEs 204 that may connect to the LMF 270 via a core network, the 5GC 260, and / or via the Internet (not shown).

[0054]

[0070] 3A, 3B, and 3C illustrate several example components (represented by corresponding blocks) that may be incorporated within a UE 302 (which may correspond to any of the UEs described herein), a base station 304 (which may correspond to any of the base stations described herein), and a network entity 306 (which may correspond to or embody any of the network functions described herein, including location server 230 and LMF 270, or alternatively, may be separate from the NG-RAN 220 and / or 5GC 210 / 260 infrastructure shown in FIGS. 2A and 2B, 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 types of devices in different implementations (e.g., within an ASIC, within a system-on-chip (SoC), etc.). The illustrated components may also be incorporated into other devices in a communication system. For example, other devices in the system may include components similar to the illustrated components to provide similar functionality. Also, a given device may include one or more of the 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.

[0055]

[0071] The UE 302 and base station 304 each include at least one wireless wide area network (WWAN) transceiver 310 and 350, respectively, that provides means for communicating (e.g., means for transmitting, means for receiving, means for measuring, means for tuning, means for refraining from transmitting, etc.) over one or more wireless communications networks (not shown), such as an NR network, an LTE network, a GSM network, etc. The WWAN transceivers 310 and 350 may be connected to one or more antennas 316 and 356, respectively, for communicating with other network nodes, such as other UEs, access points, base stations (e.g., eNBs, gNBs), etc., via at least one designated RAT (e.g., NR, LTE, GSM, etc.) over the wireless communications medium (e.g., some set of time / frequency resources within a particular frequency spectrum). The WWAN transceivers 310 and 350 may be variously configured to transmit and encode signals 318 and 358, respectively (e.g., messages, instructions, information, etc.), and conversely, to receive and decode signals 318 and 358, respectively (e.g., messages, instructions, information, pilots, etc.) in accordance with a designated RAT. Specifically, the WWAN transceivers 310 and 350 include one or more transmitters 314 and 354, respectively, to transmit and encode signals 318 and 358, respectively, and include one or more receivers 312 and 352, respectively, to receive and decode signals 318 and 358, respectively.

[0056]

[0072] The UE 302 and base station 304 each also, at least in some cases, include at least one short-range wireless transceiver 320 and 360, respectively. The short-range wireless transceivers 320 and 360 may be connected to one or more antennas 326 and 366, respectively, and may provide means for communicating (e.g., means for transmitting, means for receiving, means for measuring, means for tuning, means for refraining from transmitting, etc.) with other network nodes, such as other UEs, access points, base stations, etc., via at least one designated RAT (e.g., WiFi, LTE-D, Bluetooth, Zigbee, Z-Wave, PC5, dedicated short-range communications (DSRC), wireless access for vehicular environments (WAVE), near-field communication (NFC), etc.) over the wireless communication medium. The short-range wireless transceivers 320 and 360 may be variously configured to transmit and encode signals 328 and 368, respectively (e.g., messages, instructions, information, etc.), and conversely, to receive and decode signals 328 and 368, respectively (e.g., messages, instructions, information, pilots, etc.) in accordance with a designated RAT. Specifically, the short-range wireless transceivers 320 and 360 include one or more transmitters 324 and 364, respectively, to transmit and encode signals 328 and 368, respectively, and one or more receivers 322 and 362, respectively, to receive and decode signals 328 and 368, respectively. As specific examples, the short-range wireless transceivers 320 and 360 may be WiFi transceivers, Bluetooth® transceivers, Zigbee® and / or Z-Wave® transceivers, NFC transceivers, or vehicle-to-vehicle (V2V) and / or vehicle-to-everything (V2X) transceivers.

[0057]

[0073] The transceiver circuitry including at least one transmitter and at least one receiver may in some implementations comprise an integrated device (e.g., embodied as transmitter and receiver circuitry in a single communications device), in some implementations comprise separate transmitter and receiver devices, or in other implementations may be embodied in other manners. In certain aspects, the transmitter may include or be coupled to multiple antennas, such as an antenna array (e.g., antennas 316, 326, 356, 366), enabling each device to perform transmit "beamforming," as described herein. Similarly, the receiver may include or be coupled to multiple antennas, such as an antenna array (e.g., antennas 316, 326, 356, 366), enabling each device to perform receive beamforming, as described herein. In certain aspects, the transmitter and receiver may share the same multiple antennas (e.g., antennas 316, 326, 356, 366) such that each device can only receive or transmit at a given time, but not both simultaneously. The wireless communication devices (e.g., one or both of transceivers 310 and 320 and / or 350 and 360) of the UE 302 and / or base station 304 may also include a network listen module (NLM) or the like for performing various measurements.

[0058]

[0074] The UE 302 and base station 304 also, at least in some cases, include satellite positioning system (SPS) receivers 330 and 370. The SPS receivers 330 and 370 may be connected to one or more antennas 336 and 376, respectively, and may provide means for receiving and / or measuring SPS signals 338 and 378, respectively, 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 may comprise any suitable hardware and / or software for receiving and processing the SPS signals 338 and 378, respectively. SPS receivers 330 and 370 request information and actions from other systems as appropriate and perform the calculations necessary to determine the location of UE 302 and base station 304 using measurements obtained by any suitable SPS algorithm.

[0059]

[0075] The base station 304 and the network entity 306 each include at least one network interface 380 and 390, respectively, providing a means for communicating (e.g., a means for transmitting, a means for receiving, etc.) with other network entities. For example, the network interfaces 380 and 390 (e.g., one or more network access ports) may be configured to communicate with one or more network entities via a wire-based connection or a wireless backhaul connection. In some aspects, the network interfaces 380 and 390 may be implemented as transceivers configured to support wire-based or wireless signaling. This communication may involve, for example, sending and receiving messages, parameters, and / or other types of information.

[0060]

[0076] In certain aspects, the at least one WWAN transceiver 310 and / or the at least one short-range wireless transceiver 320 may form a (wireless) communication interface of the UE 302. Similarly, the at least one WWAN transceiver 350, the at least one short-range wireless transceiver 360, and / or the at least one network interface 380 may form a (wireless) communication interface of the base station 304. Similarly, the at least one network interface 390 may form a (wireless) communication interface of the network entity 306. The various wireless transceivers (e.g., transceivers 310, 320, 350, and 360) and wired transceivers (e.g., network interfaces 380 and 390) may be generally characterized as at least one transceiver, or alternatively, as at least one communication interface. Thus, whether a particular transceiver or communication interface relates to a wired or wireless transceiver or communication interface, respectively, can be inferred from the type of communication being performed (e.g., backhaul communication between network devices or servers generally involves signaling via at least one wired transceiver).

[0061]

[0077] The UE 302, base station 304, and network entity 306 also include other components that may be used in conjunction with operations as disclosed herein. The UE 302, base station 304, and network entity 306 each include at least one processor 332, 384, and 394, e.g., for providing functionality related to wireless communications and for providing other processing functionality. Thus, the processors 332, 384, and 394 may provide means for processing, such as determining, calculating, receiving, transmitting, and directing. In certain aspects, the processors 332, 384, and 394 may include, for example, at least one or more general-purpose processors, multi-core processors, central processing units (CPUs), ASICs, digital signal processors (DSPs), field programmable gate arrays (FPGAs), other programmable logic devices, or processing circuits, or various combinations thereof.

[0062]

[0078] The UE 302, the base station 304, and the network entity 306 include memory circuitry implementing memory components 340, 386, and 396, respectively (e.g., each including a memory device) for maintaining information (e.g., information indicative of reserved resources, thresholds, parameters, etc.). Thus, the memories 340, 386, and 396 may provide a means for storing, a means for retrieving, a means for maintaining, etc. In some cases, the UE 302, the base station 304, and the network entity 306 may include PRS modules 342, 388, and 398, respectively. The PRS modules 342, 388, and 398 may be hardware circuits that are part of or coupled to the processors 332, 384, and 394, respectively, and that, when executed, cause the UE 302, the base station 304, and the network entity 306 to perform the functions described herein. In other aspects, the PRS modules 342, 388, and 398 may be external to the processors 332, 384, and 394 (e.g., part of a modem processing system, integrated with another processing system, etc.). Alternatively, the PRS modules 342, 388, and 398 may be memory modules stored within the memory components 340, 386, and 396, respectively, and when executed by the processors 332, 384, and 394 (or modem processing system, another processing system, etc.), cause the UE 302, the base station 304, and the network entity 306 to perform the functions described herein. Figure 3A illustrates possible locations for the PRS module 342, which may be, for example, part of the at least one WWAN transceiver 310, the memory component 340, the at least one processor 332, or any combination thereof, or may be a standalone component. FIG. 3B shows possible locations for a PRS module 388, which may 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 may be a stand-alone component.FIG. 3C shows possible locations for a PRS module 398, which may 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 may be a stand-alone component.

[0063]

[0079] The UE 302 may include one or more sensors 344 coupled to the at least one processor 332 to provide a means for sensing or detecting motion and / or orientation information that is independent of motion data derived from signals received by the at least one WWAN transceiver 310, the at least one short-range wireless transceiver 320, and / or the SPS receiver 330. By way of example, the sensors 344 may include an accelerometer (e.g., a micro-electrical mechanical 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. Furthermore, the sensors 344 may include multiple different types of devices and combine their outputs to provide motion information. For example, the sensors 344 may use a combination of a multi-axis accelerometer and an orientation sensor to provide the ability to calculate position in a two-dimensional (2D) and / or three-dimensional (3D) coordinate system.

[0064]

[0080] Additionally, the UE 302 includes a user interface 346 that provides a means for providing an indication to a user (e.g., an audio and / or visual indication) and / or receiving user input (e.g., upon user actuation of a sensing device such as a keypad, touch screen, microphone, etc.). Although not shown, the base station 304 and the network entity 306 may also include user interfaces.

[0065]

[0081] Referring more particularly to the at least one processor 384, on the downlink, IP packets from the network entity 306 may be provided to the at least one processor 384. The at least one processor 384 may implement functionality for an RRC layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, and a Medium Access Control (MAC) layer. The at least one processor 384 may provide RRC layer functions associated with broadcasting system information (e.g., master information block (MIB), system information blocks (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 forwarding upper layer PDUs, error correction with automatic repeat request (ARQ), concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, scheduling information reporting, error correction, priority handling, and logical channel prioritization.

[0066]

[0082] The transmitter 354 and receiver 352 may implement Layer-1 (L1) functions associated with various signal processing functions. Layer-1, including the physical (PHY) layer, may include error detection on transport channels, forward error correction (FEC) coding / decoding of transport channels, interleaving, rate matching, mapping onto physical channels, modulation / demodulation of physical channels, and MIMO antenna processing. The transmitter 354 handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (MPSK), and M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to orthogonal frequency division multiplexing (OFDM) subcarriers, multiplexed with a reference signal (e.g., a pilot) in the time and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to generate a physical channel carrying a time-domain OFDM symbol stream. The OFDM symbol stream is spatially precoded to generate multiple spatial streams. Channel estimates from a channel estimator may be used to determine coding and modulation schemes and for spatial processing. The channel estimates may be derived from a reference signal and / or channel condition feedback transmitted by the UE 302. Each spatial stream may then be provided to one or more different antennas 356. The transmitter 354 may modulate an RF carrier with each spatial stream for transmission.

[0067]

[0083] At the UE 302, the receiver 312 receives signals through its respective antenna 316. The receiver 312 recovers information modulated onto RF carriers and provides the information to at least one processor 332. The transmitter 314 and 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 into a single OFDM symbol stream by the receiver 312. The receiver 312 then converts the OFDM symbol stream from the time domain to the frequency domain using a fast Fourier transform (FFT). The frequency-domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, as well as the reference signal, are recovered and demodulated by determining the most likely signal constellation point transmitted by the base station 304. These soft decisions may be based on channel estimates calculated by a channel estimator. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally transmitted on the physical channel by the base station 304. The data and control signals are then provided to at least one processor 332 that implements Layer-3 (L3) and Layer-2 (L2) functions.

[0068]

[0084] In the uplink, at least one processor 332 provides demultiplexing between transport and logical channels, packet reassembly, decryption, 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.

[0069]

[0085] Similar to the functionality described in connection with downlink transmission by the base station 304, the at least one processor 332 provides RRC layer functionality associated with system information (e.g., MIB, SIB) collection, RRC connection, and measurement reporting; PDCP layer functionality associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functionality associated with forwarding upper layer PDUs, error correction via ARQ, concatenation, segmentation, and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing MAC SDUs onto transport blocks (TBs), demultiplexing MAC SDUs from TBs, scheduling information reporting, error correction via hybrid automatic repeat request (HARQ), priority handling, and logical channel prioritization.

[0070]

[0086] Channel estimates derived by the channel estimator from a reference signal or feedback transmitted by the base station 304 may be used by the transmitter 314 to select an appropriate coding and modulation scheme and to facilitate spatial processing. The spatial streams generated by the transmitter 314 may be provided to different antennas 316. The transmitter 314 may modulate an RF carrier with each spatial stream for transmission.

[0071]

[0087] Uplink transmissions are processed at the base station 304 in a manner similar to that described with respect to the receiver function at the UE 302. The receiver 352 receives signals via its respective antenna 356. The receiver 352 recovers information modulated onto an RF carrier and provides the information to at least one processor 384.

[0072]

[0088] In the uplink, the at least one processor 384 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the UE 302. The IP packets from the at least one processor 384 may be provided to the core network. The at least one processor 384 is also responsible for error detection.

[0073]

[0089] For convenience, the UE 302, base station 304, and / or network entity 306 are illustrated in FIGS. 3A-3C as including various components that may be configured in accordance with various examples described herein. However, it will be understood that the illustrated components may have different functions in different designs. In particular, while some components (e.g., memory and processor components) are generally required for the operation of a computing device, various other components in FIGS. 3A-3C are optional and may vary depending on the implementation. For example, in FIG. 3A, a particular implementation of the UE 302 may omit the WWAN transceiver 310 (e.g., a wearable device, tablet computer, PC, or laptop may have Wi-Fi and / or Bluetooth functionality without cellular functionality), or may omit the short-range wireless transceiver 320 (e.g., cellular only, etc.), or may omit the SPS receiver 330, or may omit the sensor 344, etc. In another example, in the case of FIG. 3B, a particular implementation of base station 304 may omit WWAN transceiver 350 (e.g., a Wi-Fi hotspot AP without cellular capability), or may omit short-range wireless transceiver 360 (e.g., cellular only), or may omit SPS receiver 370, and so on.

[0074]

[0090] The various components of the UE 302, the base station 304, and the network entity 306 may communicate with one another via data buses 334, 382, ​​and 392, respectively. In certain aspects, the data buses 334, 382, ​​and 392 may form or be part of communication interfaces of the UE 302, the base station 304, and the network entity 306, respectively. For example, when different logical entities are embodied within the same device (e.g., gNB and location server functionality incorporated within the same base station 304), the data buses 334, 382, ​​and 392 may provide communication therebetween.

[0075]

[0091] The components of Figures 3A-3C may be implemented in various ways. In some implementations, the components of Figures 3A-3C may be implemented in one or more circuits, such as, for example, one or more processors and / or one or more ASICs (which may include one or more processors), where each circuit may use and / or incorporate at least one memory component for storing information or executable code used by the circuit to provide its functionality. For example, some or all of the functionality represented by blocks 310-346 may be implemented by the processor 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 functionality represented by blocks 350-388 may be implemented by the processor and memory components of the base station 304 (e.g., by executing appropriate code and / or by appropriate configuration of the processor components). Also, some or all of the functionality represented by blocks 390-398 may be implemented by the processor 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," "by the base station," "by the network entity," etc. However, it will be understood that such operations, actions, and / or functions may actually be performed by particular 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.

[0076]

[0092] In some designs, the network entity 306 may be implemented as a core network component. In other designs, the network entity 306 may be separate from the network operator or operation of the cellular network infrastructure (e.g., the NG RAN 220 and / or the 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).

[0077]

[0093] Various frame structures may be used to support downlink and uplink transmissions between network nodes (e.g., base stations and UEs). Figure 4A is a diagram 400 illustrating an example downlink frame structure according to an aspect of the present disclosure. Figure 4B is a diagram 430 illustrating an example channel within a downlink frame structure according to an aspect of the present disclosure. Figure 4C is a diagram 450 illustrating an example uplink frame structure according to an aspect of the present disclosure. Figure 4D is a diagram 480 illustrating an example channel within an uplink frame structure according to an aspect of the present disclosure. Other wireless communication technologies may have different frame structures and / or different channels.

[0078]

[0094] LTE and, in some instances, NR utilize OFDM on the downlink and single-carrier frequency division multiplexing (SC-FDM) on the uplink. However, unlike LTE, NR also has the option of using OFDM on the uplink. OFDM and SC-FDM partition the system bandwidth into multiple (K) orthogonal subcarriers, also commonly referred to as tones, bins, etc. Each subcarrier may be modulated with data. Generally, modulation symbols are sent in the frequency domain with OFDM and in the time domain with SC-FDM. The spacing between adjacent subcarriers may be fixed, or the total number of subcarriers (K) may depend on the system bandwidth. For example, the subcarrier spacing may be 15 kilohertz (kHz), and the minimum resource allocation (resource block) may be 12 subcarriers (i.e., 180 kHz). Thus, the nominal FFT size may be equal to 128, 256, 512, 1024, or 2048 for a system bandwidth of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), respectively. The system bandwidth may also be partitioned into subbands. For example, a subband may cover 1.08 MHz (i.e., 6 resource blocks), and there may be 1, 2, 4, 8, or 16 subbands for a system bandwidth of 1.25, 2.5, 5, 10, or 20 MHz, respectively.

[0079]

[0095] LTE supports a single numerology (subcarrier spacing (SCS), symbol length, etc.). In contrast, NR may support multiple numerologies (μ), e.g., 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 greater may be available. At each subcarrier spacing, there are 14 symbols per slot. For a 15 kHz SCS (μ=0), there is one slot per subframe, i.e., 10 slots per frame, the 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 a 30 kHz SCS (μ=1), there are two slots per subframe, i.e., 20 slots per frame, with a slot duration of 0.5 ms, a symbol duration of 33.3 μs, and a maximum nominal system bandwidth (in MHz) of 100 for a 4K FFT size. For a 60 kHz SCS (μ=2), there are four slots per subframe, i.e., 40 slots per frame, with a slot duration of 0.25 ms, a symbol duration of 16.7 μs, and a maximum nominal system bandwidth (in MHz) of 200 for a 4K FFT size. For a 120 kHz SCS (μ=3), there are eight slots per subframe, i.e., 80 slots per frame, with a slot duration of 0.125 ms, a symbol duration of 8.33 μs, and a maximum nominal system bandwidth (in MHz) of 400 for a 4K FFT size. For a 240 kHz SCS (μ=4), there are 16 slots per subframe, i.e., 160 slots per frame, the slot duration is 0.0625 ms, the symbol duration is 4.17 μs, and the maximum nominal system bandwidth (in MHz) with an FFT size of 4K is 800.

[0080]

[0096] In the example of Figures 4A-4D, a 15 kHz numerology is used. Thus, in the time domain, a 10 ms frame is divided into 10 equally sized subframes of 1 ms each, with each subframe containing one time slot. In Figures 4A-4D, time is represented horizontally (on the X-axis), with time increasing from left to right, and frequency is represented vertically (on the Y-axis), with frequency increasing (or decreasing) from bottom to top.

[0081]

[0097] A resource grid may be used to represent a time slot, and each time slot includes one or more time-parallel resource blocks (RBs) (also called physical RBs (PRBs)) in the frequency domain. The resource grid is further divided into multiple resource elements (REs). An RE may correspond to one symbol length in the time domain and one subcarrier in the frequency domain. In the numerology of FIGS. 4A-4D, for a normal cyclic prefix, an RB may include 12 consecutive subcarriers in the frequency domain and 7 consecutive symbols in the time domain, for a total of 84 REs. For an extended cyclic prefix, an RB may 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.

[0082]

[0098] Some of the REs carry downlink reference (pilot) signals (DL-RS). DL-RS may include positioning reference signals (PRS), tracking reference signals (TRS), phase tracking reference signals (TRS), cell-specific reference signals (CRS), channel state information reference signals (CSI-RS), demodulation reference signals (DMRS), primary synchronization signals (PSS), secondary synchronization signals (SSS), synchronization signal blocks (SSB), etc. Figure 4A illustrates example locations of REs carrying PRS (labeled "R").

[0083]

[0099] A set of resource elements (REs) used for transmitting a PRS is called a "PRS resource." A set of resource elements can span multiple PRBs in the frequency domain and "N" consecutive symbols (e.g., one or more) within a slot in the time domain. Within a given OFDM symbol in the time domain, a PRS resource occupies consecutive PRBs in the frequency domain.

[0084]

[0100] The transmission of PRS resources within a given PRB has a particular comb size (also called "comb density"). The comb size "N" represents the subcarrier spacing (or frequency / tone spacing) within each symbol of the PRS resource configuration. Specifically, for comb size "N," a PRS is transmitted on every Nth subcarrier of a symbol of the PRB. For example, for comb 4, for each symbol of the PRS resource configuration, an RE corresponding to every fourth subcarrier (such as subcarriers 0, 4, and 8) is used to transmit the PRS of the PRS resource. Currently, comb sizes of comb 2, comb 4, comb 6, and comb 12 are supported for DL-PRS. Figure 4A shows an example PRS resource configuration for comb 6 (spanning six symbols). That is, the location of the shaded RE (labeled "R") indicates the comb 6 PRS resource configuration.

[0085]

[0101] Currently, DL-PRS resources can span 2, 4, 6, or 12 consecutive symbols within a slot with a staggered pattern across the frequency domain. DL-PRS resources can be configured within any higher layer configured downlink or flexible (FL) symbols of a slot. There may be a constant energy per resource element (EPRE) for all REs of a given DL-PRS resource. Below are the symbol-to-symbol frequency offsets for comb sizes 2, 4, 6, and 12 across 2, 4, 6, and 12 symbols: 2-symbol-com2: {0,1}, 4-symbol-com2: {0,1,0,1}, 6-symbol-com2: {0,1,0,1,0,1}, 12-symbol-com2: {0,1,0,1,0,1,0,1,0,1,0,1}, 4-symbol-com4: {0,2,1,3}, 12-symbol-com4: {0,2,1,3,0,2,1,3,0,2,1,3}, 6-symbol-com6: {0,3,1,4,2,5}, 12-symbol-com6: {0,3,1,4,2,5,0,3,1,4,2,5}, and 12-symbol-com12: {0,6,3,9,1,7,4,10,2,8,5,11}.

[0086]

[0102] A "PRS resource set" is a set of PRS resources used for transmitting PRS signals, where each PRS resource has a PRS resource ID. In addition, PRS resources within a PRS resource set are associated with the same TRP. A PRS resource set is identified by a PRS resource set ID and associated with a specific TRP (identified by a TRP ID). In addition, PRS resources within a PRS resource set have the same periodicity across slots, a common muting pattern configuration, and the same repetition factor (e.g., "PRS-ResourceRepetitionFactor"). 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 is 2^μ * The repetition factor may have a length selected from {4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 160, 320, 640, 1280, 2560, 5120, 10240} slots, where μ=0, 1, 2, 3. The repetition factor may have a length selected from {1, 2, 4, 6, 8, 16, 32} slots.

[0087]

[0103] A 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 may transmit one or more beams). That is, each PRS resource in a PRS resource set may be transmitted on a different beam and may therefore also be referred to as a "PRS resource" or simply a "resource" or a "beam." Note that this does not have any implications regarding whether the TRP and beam on which the PRS is transmitted are known to the UE.

[0088]

[0104] A "PRS instance" or "PRS occasion" is one instance of a periodically repeating time window (e.g., a group of one or more contiguous slots) during 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 an "occasion," "instance," or "repetition."

[0089]

[0105] A "positioning frequency layer" (also simply referred to as a "frequency layer") is a collection of one or more PRS resource sets across one or more TRPs with the same values ​​for several parameters. Specifically, the collection of PRS resource sets has the same subcarrier spacing and cyclic prefix (CP) type (meaning that all numerologies supported for PDSCH are also supported for PRS), the same Point A, the same value of 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"), which is an identifier / code that specifies a pair of physical radio channels used for transmission and reception. The downlink PRS bandwidth may have a granularity of 4 PRBs, with a minimum of 24 PRBs and a maximum of 272 PRBs. Currently, up to four frequency layers are defined, and up to two PRS resource sets per TRP can be configured per frequency layer.

[0090]

[0106] The concept of a frequency layer is somewhat similar to that of a component carrier and bandwidth parts (BWP), but differs in that a component carrier and BWP are used by one base station (or a macrocell base station and a small cell base station) to transmit a data channel, while a frequency layer is used by several (usually three or more) base stations to transmit PRS. A UE may indicate the number of frequency layers it can support when it sends its positioning capabilities to the network, such as during an LTE positioning protocol (LPP) session. For example, a UE may indicate whether it can support one positioning frequency layer or four positioning frequency layers.

[0091]

[0107] FIG. 4B shows an example of various channels within a downlink slot of a radio frame. In NR, the channel bandwidth or system bandwidth is divided into multiple BWPs. A BWP is a contiguous set of PRBs selected from a contiguous subset of common RBs for a given numerology on a given carrier. Generally, up to four BWPs can be specified on the downlink and uplink. That is, a UE can be configured with up to four BWPs on the downlink and up to four BWPs on the uplink. Only one BWP (uplink or downlink) can be active at a given time, meaning that a UE can only receive or transmit via one BWP at a time. On the downlink, the bandwidth of each BWP should be equal to or greater than the bandwidth of an SSB, but each BWP may or may not include an SSB.

[0092]

[0108] Referring to FIG. 4B, a primary synchronization signal (PSS) is used by a UE to determine subframe / symbol timing and physical layer identity. A secondary synchronization signal (SSS) is used by a UE to determine a physical layer cell identity group number and 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 location of the DL-RS mentioned above. A physical broadcast channel (PBCH) carrying an MIB may be logically grouped with the PSS and SSS to form an SSB (also referred to as SS / PBCH). The MIB provides the number of RBs in the downlink system bandwidth and the system frame number (SFN). A physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted over the PBCH, such as system information blocks (SIBs), and paging messages.

[0093]

[0109] The physical downlink control channel (PDCCH) carries downlink control information (DCI) in one or more control channel elements (CCEs), where each CCE contains one or more RE group (REG) bundles (which may span multiple symbols in the time domain). Each REG bundle contains 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 set of physical resources used to carry the PDCCH / DCI is called a control resource set (CORESET) in NR. In NR, the PDCCH is limited to a single CORESET and transmitted with its own DMRS. This enables UE-specific beamforming for the PDCCH.

[0094]

[0110] In the example of Figure 4B, there is one CORESET per BWP, and the CORESET spans three symbols in the time domain (although it may be only one or two symbols). Unlike the LTE control channel, which occupies the entire system bandwidth, in NR, the PDCCH channel is confined to a specific region (i.e., the CORESET) in the frequency domain. Therefore, the frequency components of the PDCCH shown in Figure 4B are shown as being smaller than a single BWP in the frequency domain. Note that the shown CORESET is contiguous in the frequency domain, but this does not have to be the case. In addition, the CORESET may span less than three symbols in the time domain.

[0095]

[0111] The DCI in the PDCCH carries information about uplink resource allocations (persistent and non-persistent), called uplink grants and downlink grants, respectively, and a description of the downlink data to be transmitted to the UE. More specifically, the DCI indicates resources scheduled for a downlink data channel (e.g., PDSCH) and an uplink data channel (e.g., PUSCH). Multiple (e.g., up to eight) DCIs may be configured in the PDCCH, and these DCIs may have one of multiple formats. For example, different DCI formats exist for uplink scheduling, downlink scheduling, uplink transmit power control (TPC), etc. The PDCCH may be transported by 1, 2, 4, 8, or 16 CCEs to accommodate different DCI payload sizes or coding rates.

[0096]

[0112] As shown in FIG. 4C , some of the REs (labeled “R”) carry DMRS for channel estimation at a receiver (e.g., a base station, another UE, etc.). The UE may additionally transmit an SRS, for example, in the last symbol of a slot. The SRS may have a comb structure, and the UE may transmit the SRS on one of the combs. In the example of FIG. 4C , the SRS shown is comb 2 spanning one symbol. The SRS may be used by the base station to obtain channel state information (CSI) for each UE. The CSI describes how an RF signal propagates from the UE to the base station and represents the combined effects of scattering, fading, and power attenuation with distance. The system uses the SRS for resource scheduling, link adaptation, massive MIMO, beam management, etc.

[0097]

[0113] Currently, an SRS resource can span 1, 2, 4, 8, or 12 consecutive symbols within a slot with comb size Comb 2, Comb 4, or Comb 8. The following are the symbol-to-symbol frequency offsets for the 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}.

[0098]

[0114] A set of resource elements used for transmitting an SRS is called an "SRS resource" and may be identified by a parameter "SRS-ResourceId." The set of resource elements may span multiple PRBs in the frequency domain and N (e.g., one or more) consecutive symbols within a slot in the time domain. Within a given OFDM symbol, SRS resources occupy consecutive PRBs. An "SRS resource set" is a set of SRS resources used for transmitting an SRS signal and is identified by an SRS resource set ID ("SRS-ResourceSetId").

[0099]

[0115] Generally, a UE transmits an SRS to enable a receiving base station (either a serving base station or a neighboring base station) to measure the channel quality between the UE and the base station. However, the SRS may also be specifically configured as an uplink positioning reference signal for uplink-based positioning procedures such as uplink time difference of arrival (UL-TDOA), round-trip time (RTT), and uplink angle-of-arrival (UL-AoA). As used herein, the term "SRS" may refer to an SRS configured for channel quality measurement or an SRS configured for positioning purposes. When it is necessary to distinguish between the two types of SRS, the former may be referred to herein as a "communication SRS" and / or the latter may be referred to as a "positioning SRS."

[0100]

[0116] Several extensions beyond the previous definition of SRS have been proposed for SRS for positioning (also called "UL-PRS"), such as a new staggered pattern in SRS resources (except for single symbol / comb2), a new comb type for SRS, a new sequence for SRS, a larger number of SRS resource sets per component carrier, and a larger number of SRS resources per component carrier. In addition, the parameters "SpatialRelationInfo" and "PathLossReference" will be configured based on downlink reference signals or SSBs from neighboring TRPs. Furthermore, one SRS resource may be transmitted outside the active BWP, and one SRS resource may span multiple component carriers. Also, SRS may be configured in the RRC connected state and may only be transmitted within the active BWP. Furthermore, there may be no frequency hopping, no repetition factor, a single antenna port, and new lengths for SRS (e.g., 8 and 12 symbols). Also, there may be open-loop power control rather than closed-loop power control, and Com8 (i.e., SRS transmitted on every 8th subcarrier in the same symbol) may be used. Finally, the UE may transmit from multiple SRS resources over the same transmit beam for UL-AoA. All of these are additional features to the current SRS framework, configured through RRC higher layer signaling (and potentially triggered or activated through a MAC control element (CE) or DCI).

[0101]

[0117] 4D illustrates an example of various channels within an uplink slot of a frame according to an aspect of the present disclosure. A random-access channel (RACH), also referred to as a physical random-access channel (PRACH), may be present within one or more slots within a frame based on a PRACH configuration. The PRACH may include six consecutive RB pairs within a slot. The PRACH enables a UE to perform initial system access and achieve uplink synchronization. A physical uplink control channel (PUCCH) may be located on the edge of the uplink system bandwidth. The PUCCH carries uplink control information (UCI), such as scheduling requests, CSI reports, channel quality indicators (CQIs), precoding matrix indicators (PMIs), rank indicators (RIs), and HARQ ACK / NACK feedback. The physical uplink shared channel (PUSCH) carries data and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and / or UCI.

[0102]

[0118] It should be noted that the terms “positioning reference signal” and “PRS” generally refer to specific reference signals used for positioning in NR and LTE systems. However, as used herein, the terms “positioning reference signal” and “PRS” may also refer to any type of reference signal that can be used for positioning, such as, but not limited to, PRS defined in LTE and NR, TRS, PTRS, CRS, CSI-RS, DMRS, PSS, SSS, SSB, SRS, UL-PRS, etc. In addition, the terms “positioning reference signal” and “PRS” may refer to downlink or uplink positioning reference signals, unless otherwise suggested by the context. If necessary to further distinguish between PRS types, downlink positioning reference signals may be referred to as “DL-PRS,” and uplink positioning reference signals (e.g., SRS for positioning, PTRS) may be referred to as “UL-PRS.” In addition, for signals that can be transmitted in both uplink and downlink (e.g., DMRS, PTRS), “UL” or “DL” may be prepended to the signal to distinguish the direction. For example, "UL-DMRS" can be distinguished from "DL-DMRS."

[0103]

[0119] 5 is a diagram of example PRS resource sets with different time gaps according to an embodiment of the present disclosure. In the example of FIG. 5, time is represented horizontally and frequency is represented vertically. Each block represents a slot in the time domain and some bandwidth in the frequency domain.

[0104]

[0120] 5 shows two DL-PRS resource set configurations, a first DL-PRS resource set configuration 510 and a second DL-PRS resource set configuration 550. Each DL-PRS resource set configuration 510 and 550 comprises 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 (i.e., transmitted four times) within the DL-PRS resource set. That is, there are four repetitions of each of the four PRS resources within the DL-PRS resource set.

[0105]

[0121] The DL-PRS resource set configuration 510 has a one-slot time gap, meaning that each repetition of a PRS resource (e.g., "Resource 1") starts on the first slot after the previous repetition of that PRS resource. Thus, as shown by 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 slots (i.e., slots n through n+3) of the DL-PRS resource set configuration 510, the four repetitions of PRS resource "Resource 2" occupy the second four slots (i.e., slots n+4 through n+7), the four repetitions of PRS resource "Resource 3" occupy the third four slots (i.e., slots n+8 through n+11), and the four repetitions of PRS resource "Resource 4" occupy the last four slots (i.e., slots n+12 through n+15).

[0106]

[0122] In contrast, DL-PRS resource set configuration 550 has a four-slot time gap, meaning that each repetition of a PRS resource (e.g., "resource 2") starts on the fourth slot after the previous repetition of that PRS resource. Thus, as shown by DL-PRS resource set configuration 550, the four repetitions of each of the four PRS resources are scheduled every four slots. For example, the four repetitions of PRS resource "resource 1" occupy the first, fifth, ninth, and thirteenth slots (i.e., slots n, n+4, n+8, and n+12) of DL-PRS resource set configuration 550.

[0107]

[0123] Note that the duration spanned by one DL-PRS resource set containing repeated DL-PRS resources should not exceed the PRS periodicity as shown in Figure 5. Additionally, the UE receive beam sweep for receiving / measuring the DL-PRS resource set is not specified, but rather depends on the UE implementation.

[0108]

[0124] NR supports several 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 an OTDOA or DL-TDOA positioning procedure, a UE measures the difference between the time of arrival (ToA) of reference signals (e.g., positioning reference signals (PRS)) received from pairs of base stations, called reference signal time difference (RSTD) or time difference of arrival (TDOA) measurements, and reports them to a positioning entity. More specifically, the UE receives identifiers (IDs) of a reference base station (e.g., a serving base station) and multiple non-reference base stations in the assistance data. The UE then measures the RSTD between the reference base station and each of the non-reference base stations. Based on the known locations of the involved base stations and the RSTD measurements, the positioning entity can estimate the location of the UE.

[0109]

[0125] For DL-AoD positioning, the positioning entity uses beam reports from the UE of received signal strength measurements of multiple downlink transmit beams to determine the angle between the UE and the transmitting base station. The positioning entity can then estimate the location of the UE based on the determined angle and the known location of the transmitting base station.

[0110]

[0126] Uplink-based positioning methods include uplink time difference of arrival (UL-TDOA) and uplink angle of arrival (UL-AoA). UL-TDOA is similar to DL-TDOA, but is based on uplink reference signals (e.g., sounding reference signals (SRS)) transmitted by the UE. For UL-AoA positioning, one or more base stations measure the received signal strength of one or more uplink reference signals (e.g., SRS) received from the UE on one or more uplink receive beams. The positioning entity uses the signal strength measurements and the angles of the receive beams to determine the angle between the UE and the base station. Based on the determined angle and the known location of the base station, the positioning entity can then estimate the location of the UE.

[0111]

[0127] Downlink and uplink-based positioning methods include enhanced cell-ID (E-CID) positioning and multi-round trip time (RTT) positioning (also referred to as "multi-cell RTT"). In the RTT procedure, an initiator (base station or UE) transmits an RTT measurement signal (e.g., PRS or SRS) to a responder (UE or base station), and the responder returns an RTT response signal (e.g., SRS or PRS) 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, called the transmit / receive (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, called the transmit / receive (Tx-Rx) time difference. The propagation time (also referred to as "time of flight") between the initiator and the responder can be calculated from the Tx-Rx time difference and the RxTx time difference. Based on the propagation time and the known speed of light, the distance between the initiator and the responder can be determined. For multi-RTT positioning, the UE performs RTT procedures with multiple base stations to allow its location to be determined based on the known locations of the base stations (e.g., using multilateration). RTT and multi-RTT methods may be combined with other positioning techniques, such as UL-AoA and DL-AoD, to improve location accuracy.

[0112]

[0128] 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 identities, estimated timing, and signal strength of detected neighboring base stations. The UE's location is then estimated based on this information and the known locations of the base stations.

[0113]

[0129] To assist positioning operations, a location server (e.g., location server 230, LMF 270, SLP 272) may provide assistance data to the UE. For example, the assistance data may include identifiers of base stations (or base station cells / TRPs) from which to measure reference signals, reference signal configuration parameters (e.g., number of consecutive positioning subframes, periodicity of the positioning subframes, muting sequence, frequency hopping sequence, reference signal identifier, reference signal bandwidth, etc.), and / or other parameters applicable to a particular positioning method. Alternatively, the assistance data may originate directly from the base stations themselves (e.g., in periodically broadcast overhead messages, etc.). In some cases, the UE may be able to detect neighboring network nodes itself without using assistance data.

[0114]

[0130] In the case of an OTDOA or DL-TDOA positioning procedure, the assistance data may further include an expected RSTD value and an associated uncertainty around the expected RSTD, i.e., a search window. In some cases, the value range for the expected RSTD may be + / - 500 microseconds (μs). In some cases, when any of the resources used for positioning measurements are in FR1, the value range for the expected RSTD uncertainty may be + / - 32 μs. In other cases, when all of the resources used for positioning measurements are in FR2, the value range for the expected RSTD uncertainty may be + / - 8 μs.

[0115]

[0131] A location estimate may be referred to by other names, such as a position estimate, location, position, position determination, or determination. A location estimate may be geodetic and comprise coordinates (e.g., latitude, longitude, and possibly altitude), or urban and comprise a street address, postal address, or some other linguistic description of the location. A location estimate may also be defined relative to some other known location, or may be defined absolutely (e.g., using latitude, longitude, and possibly altitude). A location estimate may include an expected error or uncertainty (e.g., by including an area or volume within which the location is expected to lie with some specified or default level of confidence).

[0116]

[0132] FIG. 6 illustrates an exemplary wireless communication system 600 implementing positioning using a downlink time difference of arrival (TDOA) technique. In the example of FIG. 6, the 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.) to determine an estimate of its location. The UE 104 may wirelessly communicate with multiple base stations 102-1, 102-2, and 102-3 (collectively, base stations 102), which may correspond to any combination of base stations 102, 180 in FIG. 1, using RF signals and standardized protocols for modulating the RF signals and exchanging information packets. By extracting different types of information from the exchanged RF signals and utilizing the layout of the wireless communication system 600 (i.e., base station locations, geometric arrangements, etc.), the UE 104 may determine or assist in determining its location in a predefined reference coordinate system. In an aspect, the UE 104 may specify its location using a two-dimensional coordinate system. However, the aspects disclosed herein are not so limited and may equally be applicable to determining position using a three-dimensional coordinate system if additional dimensions are desired. Additionally, while Figure 6 shows one UE 104 and three base stations 102, it will be understood that there may be more UEs 104 and more or fewer base stations 102.

[0117]

[0133] To support position estimation, the base station 102 may be configured to broadcast reference RF signals (e.g., PRS, CRS, CSI-RS, synchronization signals, etc.) to the UE 104 within the coverage area of ​​the base station 102 to allow the UE 104 to measure characteristics of such reference RF signals. For example, FIG. 6 shows that the base station 102-1 transmits a downlink reference signal (PRS) 602 to the UE 104, and the base stations 102-2 and 102-3 transmit downlink reference signals (PRS) 604 and 606, respectively, to the UE. The UE 104 may use a DL-TDOA (e.g., OTDOA) positioning method, which is a multilateration method in which the UE conventionally 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., the base station 102, the antennas of the base station 102, etc.). Transmit and / or receive beamforming at the base station and / or UE 104 may allow for wider bandwidth for improved accuracy. The TOAs from several neighboring base stations may be subtracted from the TOA from the reference base station to determine the RSTD for the base station pair.

[0118]

[0134] Generally, RSTD is measured between a reference network node and one or more neighboring network nodes. In the example shown in FIG. 6, base station 102-1 may be the serving base station for UE 104 and may further serve as the reference base station, and base stations 102-2 and 102-3 serve as neighboring base stations. The reference network node remains the same for all RSTD measured by UE 104 for any single positioning application of OTD-OA and generally corresponds to the serving cell for UE 104 or another nearby cell with good signal strength at UE 104. In an aspect, when the measured network node is a cell supported by a base station, the neighboring network node is typically a cell supported by a different base station than the base station for the reference cell, and may have good or bad signal strength at UE 104. RSTD is traditionally the relative timing difference between two cells, e.g., between a reference cell and a neighboring cell, and is determined based on the minimum time difference between two subframe boundaries from two different cells.

[0119]

[0135] Location calculations may be based on measured time differences (e.g., RSTD) and knowledge of the network node locations and relative transmission timing (e.g., whether the network nodes are precisely synchronized or whether each network node transmits with some known time difference relative to other network nodes).

[0120]

[0136] To assist in positioning operations, the location server 172 shown in FIG. 1A (e.g., the LMF 270 shown in FIG. 2B) may provide the UE 104 with OTDOA assistance data for a reference network node (e.g., the base station 102-1 in the example of FIG. 6) and neighboring network nodes with respect to the reference network node (e.g., the base stations 102-2 and 102-3 in the example of FIG. 6). For example, the assistance data may provide the center channel frequency of each network node, various reference RF signal configuration parameters (e.g., the number of consecutive positioning subframes, the periodicity of the positioning subframes, the muting 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 for the UE 104 as the reference network node.

[0121]

[0137] In an aspect, the location server 172 (e.g., the LMF 270) may send the assistance data to the UE 104, but alternatively, the assistance data may originate directly from the network node (e.g., the base station 102) itself (e.g., in periodically broadcast overhead messages, etc.) Alternatively, the UE 104 may detect neighboring network nodes itself without using assistance data.

[0122]

[0138] 6, the time differences measured between the reference cell of base station 102-1 and the neighboring cells of base stations 102-2 and 102-3 are represented as τ−τ and τ−τ, where τ, τ, and τ represent the times of reception of the reference RF signals from the transmit antennas of base stations 102-1, 102-2, and 102-3, respectively, by UE 104, including any measurement noise at UE 104. UE 104 may then convert the ToA measurements for different network nodes into RSTD measurements (e.g., as defined in 3GPP TS 36.214 entitled “Physical layer; Measurements”) and (optionally) send them to location server 172. Using (i) RSTD measurements, (ii) known absolute or relative transmit timing of each network node, (iii) known locations of physical transmit antennas for the reference network node and neighboring network nodes, and / or (iv) directional reference RF signal characteristics such as direction of transmission, the location of the UE 104 can be determined (either by the UE 104 or by the location server 172 (e.g., the LMF 270)).

[0123]

[0139] ToA T at UE 104 for the shortest path from base station i i teeth,

[0124]

number

[0125] where D i is the location (q i ) and the UE 104 at location (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

[0126]

number

[0127]

[0140] where D is the distance between two points on the Earth's surface, R is the Earth's radius (6371 km), φ1, φ2 are the latitude (in radians) of the first point and the latitude (in radians) of the second point, respectively, and β1, β2 are the longitude (in radians) of the first point and the latitude (in radians) of the second point, respectively.

[0128]

[0141] To identify the ToA of a reference RF signal transmitted by a given network node, the UE 104 first processes all resource elements (REs) on the channel on which that network node (e.g., base station 102) is transmitting the reference RF signal together and performs an inverse Fourier transform to convert the received RF signal to the time domain. Converting the received RF signal to the time domain is called estimating the channel energy response (CER). The CER indicates the peaks on the channel over time, and therefore the earliest “valid” peak should correspond to the ToA of the reference RF signal. Typically, the UE uses a noise-related quality threshold to remove false local peaks, thereby correctly identifying the likely valid peak on the channel. For example, the UE 104 may choose the ToA estimate that is the earliest local maximum of the CER that is at least X dB higher than the median CER and up to Y dB lower than the main peak on the channel. The UE 104 determines the CER for each reference RF signal from each network node to determine the ToA of each reference RF signal from different network nodes.

[0129]

[0142] The TOA measurements performed by the UE 104 relate to the geographic distance between the UE and the base station 102. In a 2D Cartesian coordinate system, the (known) coordinates of the base station are x i =[x i ,y i ] T and the (unknown) coordinates of the UE 104 can be expressed as x t =[x t ,y t ] TThe RSTD measurement may be defined as the time difference between two base stations, modulo 1 subframe (1 ms), and thus corresponds to the distance difference between the neighbor base station 102-i and the reference base station 102-1.

[0130]

number

[0131]

[0143] In Equation 2, RSTD i,1 is the time difference between the neighbor base station 102-i and the reference base station 102-1 as measured at the UE 104, and (T i -T1) is the transmission time offset between base stations, called the "Real Time Differences (RTD)." i and n1 is the UE TOA measurement error, and c is the speed of light.

[0132]

[0144] At least two neighbor base station measurements i are required, but three or more neighbor base station measurements are desirable, and the simultaneous equations can be solved in a least-squares or weighted least-squares manner. The transmit time offset (Ti-T1) should (ideally) be zero in a synchronized network, 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 shown in FIG. 6. If the base station 102 coordinates and transmit time offset (Ti-T1) are known in the location server 172 (e.g., LMF 270) or in the UE 104, the location of the UE 104 can be determined. Uncertainty in the base station 102 coordinates or transmit time offset directly impacts the accuracy of the UE location estimate. An additional source of delay or error is due to the UE and gNB hardware group delay, which is primarily due to internal hardware delays between the baseband (BB) component and the antenna (ANT) in the UE and gNB. Hardware group delays can contribute to timing and / or calibration errors that can affect positioning measurements, which in turn can affect positioning performance.

[0133]

[0145] Therefore, in traditional OTDOA measurements, highly accurate and reliable network synchronization is critical to accuracy. At the speed of light, each nanosecond error in timing translates to approximately one foot (approximately 0.3 m) of error in position. As base station synchronization deteriorates, OTDOA measurements become less accurate, as shown by the hyperbola in Figure 6, for example, and position error increases proportionally. However, synchronization requirements for OTDOA are much more stringent than those for communications purposes.

[0134]

[0146] Uplink Time Difference of Arrival (UTDOA) is a positioning method similar to OTDOA, but is based on an uplink reference RF signal, e.g., a UL PRS or SRS transmitted by a UE (e.g., UE 104). Additionally, transmit and / or receive beamforming at the network node and / or UE 104 may enable wider bandwidth at the cell edge for improved accuracy. Beam refinement may also leverage channel reciprocity procedures in 5G NR. As with OTDOA, lack of synchronization during UTDOA positioning results in degraded accuracy.

[0135]

[0147] FIG. 7 illustrates an exemplary wireless communication system 700 illustrating a positioning implementation using an uplink time difference of arrival (TDOA) technique. FIG. 7 is similar to FIG. 6 discussed above, but illustrates UTDOA instead of OTDOA. As shown, the UE 104 transmits an SRS 702 to the reference base station 102-1 while simultaneously transmitting SRSs 704 and 706 to neighbor base stations 102-2 and 102-3, respectively. In some implementations, the SRSs 702, 704, and 706 may be the same transmission. In other implementations, the SRSs 702, 704, and 706 may be separate transmissions, where the UE 104 measures and stores the time between the transmission of the SRSs 702 and 704 and between the transmission of the SRSs 702 and 706.

[0136]

[0148] Assuming the base stations 102 are synchronized, the RSTD for SRSs 702 and 704 may then be determined based on the difference between the reception times of SRSs 702 and 704 at base stations 102-1 and 102-2, respectively, minus any delay between the transmissions of SRSs 702 and 704 (if any) at the UE 104. Similarly, the RSTD for SRSs 702 and 706 may be determined based on the difference between the reception times of SRSs 702 and 706 at base stations 102-1 and 102-3, respectively, minus any delay between the transmissions of SRSs 702 and 706 (if any) at the UE 104. The location of the UE 104 may then be determined based on the intersection of the resulting hyperbolic curves, similar to the discussion above.

[0137]

[0149] While positioning techniques such as DL TDOA and UL TDOA shown in FIGS. 6 and 7 generally involve measurement procedures between a target UE and multiple base stations, in some designs, a reference device associated with a known location may be involved in one or more positioning procedures. For example, sidelink positioning using another UE or other device, e.g., with a known location, that may communicate with the target UE 104 via sidelink communication, may be used in place of one or more base stations in the measurement procedures. The use of sidelink for positioning may be desirable because it enables more flexible deployment using anchor devices in the form of UEs, e.g., in environments where satellite-based positioning, such as Global Navigation Satellite System (GNSS), or network positioning, is impaired. For example, in indoor environments, e.g., shopping malls, manufacturing plants, etc., or in urban canyons, GNSS signal reception or network signal reception for positioning may be poor, or multipath components, interference, etc. may be present that make positioning difficult. Furthermore, sidelink positioning can operate independently of network coverage and therefore may have lower latency because it does not require the establishment of a network connection prior to positioning. Sidelink positioning also enables relative positioning without the need for absolute position calculations. Relative positioning using sidelink can be useful, for example, in public safety operations (e.g., tracking emergency personnel), vehicle applications (e.g., platooning, collision avoidance), unmanned aerial vehicle (UAV) applications (e.g., approaching or landing at a docking station), augmented reality (AR) applications (e.g., user interaction within AR), smart home entertainment applications (e.g., connectivity and interaction between devices), etc.

[0138]

[0150] A reference device, such as a UE, roadside unit (RSU), or other UE with a recent positioning fix, may be configured to support downlink-related positioning such as DL-TDOA, uplink-related positioning such as UL-TDOA, or a combination of downlink-related and uplink-related positioning such as RTT. The reference device may be configured to support measurement of DL-PRS (or sidelink (SL-PRS)) and report associated measurements (e.g., RSTD, RxTx time difference, RSRP) to the LMF (or UE for UE-based positioning), and to transmit UL-PRS (or SL-PRS) and report associated measurements (e.g., Tx time, RxTx time difference, etc.). The reference device may be referred to herein as an anchor device for positioning. In addition, a base station may also be referred to as a (stationary) anchor device for positioning.

[0139]

[0151] 8 shows, by way of example, 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), a reference device B (e.g., a UE 104 or another base station 102 with a known location), etc. BS A and reference device B, in this example, are stationary and have known positions. The timing diagram 800 of FIG. 8 illustrates the difference (T_RxTx) between the time of reception Rx of PRS#1 by reference device B and the time of transmission of PRS#2 (T_RxTx) as τ B and the difference between the time of reception Rx of PRS#1 at the target UE 104 and the time of reception Rx of PRS#2 (T_Rx-Rx) is denoted as τ UE Shown as

[0140]

number

[0141] represents a measured value in this specification.

[0142]

[0152] TDOA-based positioning heavily relies on network synchronization (between gNBs) for positioning accuracy. By introducing a reference device (hereafter denoted as reference device B) with a known stationary location (either UE or gNB), the requirement for gNB synchronization is reduced to the inter-anchor time measurement T oF (A,B) (Rx-Tx time difference) is RSTD(T RSTD =T oF (B,UE)-T oF (A,UE)) calculation, which allows

[0143]

number

[0144]

[0153] Here, T oF (time of flight) is the propagation time between two nodes, and T oF (A,B) may be obtained from almanac information (e.g., the locations of BS A and reference device B are known, so the propagation delay between BS A and reference device B may be calculated rather than measured).

[0145]

[0154] Assuming a constant clock drift during the short period τ, the measured

[0146]

number

[0147]

number

[0148] Depends on, for example,

[0149]

number

[0150]

[0155] where τ B (e UE -e B ) is the main part of the error, and (e UE -e B ) may be ±0.2 ppm.

[0151]

[0156] In some systems, this level of error may not be acceptable. For example, in some designs, the average value of the fundamental measurement of the UE modulation carrier frequency may be required to be accurate to within ±0.1 PPM observed over a 1 ms cumulative measurement interval period compared to the carrier frequency received from the NR Node B.

[0152]

[0157] In some designs, the error due to time drift is mainly due to the gap from PRS#1 to PRS#2 (τ B With the increased accuracy requirements in 3GPP Ref-17 (e.g., 1 m for general commercial use or 20 cm for IIoT), for an accumulated ±0.2 ppm, assuming a 10% error budget, the required maximum PRS#1 to PRS#2 gap may be 1.67 msec and 0.33 msec, respectively, e.g.,

[0153]

number

[0154]

[0158] Figure 9 shows an example process 900 for a TDOA procedure that uses time drift mitigation to improve positioning accuracy for position estimation of a target UE 104. In Figure 9, similar to Figure 8, measurement signals are exchanged between BS A (e.g., base station 102), reference device B (e.g., UE 104 or another base station 102 with a known location), and target UE 104. BS A and reference device B are stationary and have known locations in this example.

[0155]

[0159] By way of background, the baseline DL-TDOA algorithm:

[0156]

number

[0157] and [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.,

[0158]

number

[0159]

[0160] Here, T oF (A,B) can be obtained from almanac information (e.g., the locations of BS A and reference device B are known, so the propagation delay between BS A and reference device B can be calculated rather than measured). In this case, the error is 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. To be effective, the drift-corrected reference duration

[0160]

number

[0161] must be long to be valid, otherwise a multiplicative correction factor, e.g.

[0162]

number

[0163] is the constant 1.

[0164] In an example, the paired RSTD may be measured by the target UE 104, which may be, for example,

[0165]

number

[0166] In order to obtain RSTD, the UE associates with a pair of PRSs (PRS#1 and #3) from BS A and another PRS (PRS#2) from reference device B. In case of UE-assisted positioning, the measured RSTD is reported to the LMF. An alternative option is to

[0167]

number

[0168] In some designs, for example,

[0169]

number

[0170] Paired RxTx time difference measured by reference device B associated with paired PRS (PRS#1 and #3) from BS A to obtain. In case of UE assisted positioning, the paired RxTx time difference is reported to the LMF. In case of UE based positioning, the paired RxTx time difference is reported to the UE. Alternative options are:

[0171]

number

[0172] The objective is to report the ratio associated with

[0173] The use of a reference device such as reference device B in Figures 8 and 9 assumes that the reference device is stationary. However, a stationary reference device is not 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 may be mobile. As an example, a mobile reference device with a known location may be a vehicle UE.

[0174]

[0163] For example, in a Vehicle-to-Everything (V2X) wireless system, a moving vehicle UE may be utilized as multiple reference devices (anchors) over time to position a relatively stationary target UE, e.g., a UE held by a pedestrian.

[0175] 10 illustrates a wireless communication system 1000 showing vehicle-to-everything (V2X) communications used for positioning of a target UE 104, for example, using downlink time difference of arrival (TDOA) techniques with a fixed (stationary) anchor 1002 and a mobile anchor 1006. It should be appreciated that FIG. 10 illustrates a single mobile anchor 1006 at multiple times (t1, t2, t3, and t4) illustrating the change in position of the mobile anchor 1006 over time relative to the target UE 104. The mobile anchor 1006 is shown, for example, at times t2, t3, and t4 as a dotted line and in a lighter color than it is shown at time t1.

[0176] In some implementations, the wireless communication system 1000 may be a Cellular V2X (C-V2X) system. Generally, there are two modes of operation for V2X services, as defined in 3GPP TS 23.285. One mode of operation uses direct wireless communication between the V2X entities, e.g., the target UE 104, the fixed anchor 1002, and the mobile anchor 1006. The other mode of operation uses network-based wireless communication between the entities. If desired, the two modes of operation may be combined, or other modes of operation may be used.

[0177] 10 , the wireless communication system 100 may operate using direct or indirect wireless communication between the target UE 104, the fixed anchor 1002, and the mobile anchor 1006. For example, the wireless communication may be via the Proximity-based Services (ProSe) Direct Communication (PC5) reference point defined in 3GPP TS23.303, may use wireless communication over the 5.9 GHz ITS band under IEEE 1609, Wireless Access in Vehicular Environments (WAVE), Intelligent Transport Systems (ITS), IEEE 802.11p, or other wireless connection between direct entities. The wireless communication system 100 may use, for example, a Vehicle-to-Everything (V2X) communication standard in which information is passed between vehicles and other entities in a wireless communication network. V2X services include, for example, vehicle-to-vehicle (V2V), vehicle-to-pedestrian (V2P), vehicle-to-infrastructure (V2I), and vehicle-to-network (V2N) services. The V2X standard aims to develop autonomous or semi-autonomous driving systems, such as ADAS, that assist drivers with critical decisions such as lane changes, speed changes, and overtaking speeds, and may be used to assist parking as discussed herein. V2X uses low-latency communications and is therefore suitable for precise relative positioning, e.g., RTT, TDOA, etc.

[0178] In some implementations, the fixed anchor 1002 may be a roadside unit (RSU) in a V2X system. The RSU may, for example, support V2X applications and exchange messages with other entities supporting V2X applications. The RSU may be a logical entity that can combine V2X application logic with the functionality of a base station in a RAN, such as an eNB, ng-eNB, or eLTE (referred to as an eNB-type RSU), or a gNB, or a UE (referred to as a UE-type RSU). If the fixed anchor 1002 is an RSU, it may communicate with the base station 102 over the communication channel 120 along with one or more of the UE 104 and the mobile anchor 1006. In some implementations, the fixed anchor 1002 may be a stationary base station 102 or another UE 104 with a known location.

[0179] As shown, the target UE 104, the fixed anchor 1002, and the mobile anchor 1006 may directly communicate and transmit 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 1002 may directly communicate and transmit positioning signals using communication link 1005, the target UE 104 and the mobile anchor 1006 may directly communicate and transmit positioning signals using communication link 1007, and the fixed anchor 1002 and the mobile anchor 1006 may directly communicate and transmit positioning signals using communication link 1003. The PRS broadcast by the target UE 104, the fixed anchor 1002, and the mobile anchor 1006 may be any signal suitable for ranging, such as defined for DSRC or C-V2X. The PRS may be broadcast on licensed or unlicensed spectrum. For example, in some implementations, the PRS may be broadcast on one or more Unlicensed National Information Infrastructure (UNII) radio bands, including, for example, one or more of the UNII-1 radio band, the UNII-2A radio band, the UNII-2B radio band, or the UNII-3 radio band. When broadcast on unlicensed spectrum, a listen before transmit (LBT) protocol may be employed.

[0180] The mobile anchor 1006 may be a vehicle UE (or other mobile entity) that has a precise position over the time period during which TDOA measurements are made. For example, at a first time (t1) during TDOA positioning of the target UE 104, the mobile anchor 1006 may have a precise position, e.g., through GNSS positioning techniques or terrestrial positioning techniques. At subsequent times during TDOA positioning of the target UE 104, e.g., times t2, t3, and t4, the mobile anchor 1006 may have a known position, e.g., through dead reckoning based on its initial position at time t1 and mobility information (including speed, yaw / pitch / roll, acceleration, etc.) provided by on-board sensors of the vehicle, such as an accelerometer, gyroscope, wheel tick sensor, etc. Additionally or alternatively, updated positions of the mobile anchor 1006 at subsequent times may be obtained, e.g., using GNSS positioning techniques or terrestrial positioning techniques.

[0181] For moving anchors, the TDOA algorithm for compensating for drift shown in Figure 9 and Equation 6 cannot be extended in a straightforward manner. For example, as discussed, to be effective, the drift-correction reference duration shown in Figure 9

[0182]

number

[0183] must be long to be valid, otherwise a multiplicative correction factor, e.g.

[0184]

number

[0185] is a constant 1. If reference device B in Figure 9 is moving, during the long period between the transmission of PRS#1 and PRS#3 by BS A, reference device B will move away from its initial position. For example, for a vehicle with a speed of 30 m / s, a drift-corrected reference duration of 200 ms between PRS#1 and PRS#3 will cause reference device B to move 6 m from its initial location.

[0186]

[0171] Thus, if reference device B in Figure 9 is moving, for example if reference device B is mobile anchor 1006 shown in Figure 10, reference device B can be treated as two virtual anchors at different locations, for example, a distance of 6 m in the above example. The change in position of the mobile anchor can modify the time drift mitigation shown in Figure 9.

[0187] FIG. 11 illustrates, by way of example, an exemplary process 1100 for a TDOA procedure that improves positioning accuracy for location estimation of a target UE 104 using time drift mitigation for a moving anchor.

[0188] 11, measurement signals are exchanged between anchor A 1002, which may be an RSU, another UE with a known location, a base station 102, etc., mobile anchor B 1006, which may be a vehicular UE or other mobile UE, and a target UE 104. In FIG. 11, anchor A 1002 and target UE 104 are relatively stationary, while mobile anchor B 1006 is moving and is therefore treated as several virtual anchors. FIG. 11, for example, illustrates the same mobile anchor B 1006 as three virtual anchors (i.e., mobile anchor B 1006, mobile anchor B' 1006, and mobile anchor B'' 1006), which are at different relative positions relative to the target UE 104 over time, shown as separate timelines t1, t2, and t3, respectively. Timelines t1, t2, and t3 may correspond, for example, to times t1, t2, and t3 shown in FIG. 10. Additionally, the RSTD set generated by the signaling exchange for the TDOA procedure in Figure 11 is shown as three RSTD measurement instances 1110, 1120, and 1130 identified by dashed boxes, each associated with mobile anchor B 1106 at corresponding times t1, t2, and t3. While three RSTD measurement instances 1110, 1120, and 1130 are shown within the RSTD set in Figure 11, it should be understood that additional RSTD measurement instances, for example, corresponding to time t4 (and additional times) shown in Figure 10, may be included within the RSTD set if desired. The TDOA determined based on the RSTD measurement instances 1110, 1120, and 1130 from times t1, t2, and t3 define hyperbolic curves 1010, 1020, and 1030 shown in Figure 10 that intersect at the location of the target UE 104. Thus, using the known location of anchor A 1002 and the known location of mobile anchor B 1006 at each of times t1, t2, and t3, the position of target UE 104 can be determined.

[0189]

[0174] As shown by the RSTD set shown in Figure 11, fixed anchor A1002 transmits reference signals (PRS) for multiple RSTD measurement instances (e.g., PRS#1, PRS#3, and PRS#5 transmitted in respective RSTD measurement instances 1110, 1120, and 1130), and mobile anchor B1006 transmits corresponding reference signals (PRS) in multiple RSTD measurement instances (e.g., PRS#2, PRS#4, and PRS#6 transmitted in RSTD measurement instances 1110, 1120, and 1130).

[0190] 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, anchor A 1002 transmits PRS#1 for a period of time τ B,1 After t, 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 through #3, anchor A 1002 transmits PRS#3, which is received by mobile anchor B' 1006 (at time t) and by target UE 104. In response to receiving PRS#3, B’,3 After time t, 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 through #5, anchor A 1002 transmits PRS#5, which is received by target UE 104. In addition (at time t), mobile anchor B'' 1006 transmits PRS#6, which is received by target UE 104. Note that in RSTD measurement instance 1130, mobile anchor B'' 1006 does not need to receive PRS#6 or monitor the period between receiving PRS#5 from anchor UE 1002 and transmitting PRS#6 to target UE 104.

[0191] 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 the target UE 104. 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, and therefore these RSTD involve "inter-anchor" procedures. For example, in RSTD measurement instance 1110, the RxTx time difference between receiving PRS#1 and transmitting PRS#2 is τ B,1 and when measured by the moving anchor B1006,

[0192]

number

[0193] , whereas in RSTD measurement instance 1120, the RxTx time difference between receiving PRS#3 and transmitting PRS#4 is τ B’,3 and measured by the moving anchor B'1006,

[0194]

number

[0195] It is marked as follows.

[0196] The RxTx time difference measured in the two RSTD measurement instances may be used to determine a clock drift error that may result from non-ideal synchronization between anchor A 1002 and mobile anchor B 1006. Once the clock drift error has been determined using two RSTD measurement instances (e.g., RSTD measurement instances 1110 and 1120), an additional RSTD measurement instance may be measured for the RSTD set (RSTD measurement instance 1130) without inter-anchor procedures, i.e., without measuring the RxTx time difference between receiving a reference signal (PRS) from anchor A 1002 and transmitting a reference signal (PRS) to the target UE 104. If desired, once the clock drift error has been determined, the RSTD set may include multiple RSTD measurement instances without inter-anchor procedures.

[0197]

[0178] Although Figure 11 shows two adjacent RSTD measurement instances (i.e., RSTD measurement instances 1110 and 1120) that involve inter-anchor procedures, it should be understood that there may be one or more intervening RSTD measurement instances that do not involve inter-anchor procedures, if desired.

[0198]

[0179] The clock drift error resulting from non-ideal synchronization between anchor A 1002 and mobile anchor B 1006 can be identified as follows: As can be seen in Figure 11, τ UE,1 =[T oF (A,B)-T oF (A,UE)]+τ B,1 +T oF (B,UE))Equation 7

[0199]

[0180] Therefore, in the case of non-ideal anchor synchronization, the baseline DL-TDOA algorithm for the RSTD measurement instance 1110 may be written as follows:

[0200]

number

[0201]

[0181] The time gap (configured slot offset in milliseconds) between the transmission of PRS#1 and the transmission of PRS#2 is T PRS#1-to-#2 For ideal anchor synchronization, the baseline DL-TDOA algorithm may be written as:

[0202]

number

[0203]

[0182] Therefore, the synchronization bias can be determined by subtracting Equation 8 and Equation 9, resulting in:

[0204]

number

[0205] Similarly, for PRS#3 and PRS#4 in RSTD measurement instance 1120, the synchronization bias may be written as follows:

[0206]

number

[0184] Assuming that the variation in anchor synchronization bias is due only to clock drift (where e A is the error at anchor A1002, and e B is the error at mobile anchor B 1006), the synchronization bias of PRS#3 and PRS#4 may be written as:

[0207]

number

[0208] Therefore, as seen in Equation 13, the clock drift error (e B -e A) is the RxTx time difference (τ B,1 ) and the RxTx time difference (τ B,2 ) is a function of the measurands including

[0209]

[0186] Clock drift error (e B -e A ) is determined, additional RSTD measurement instances (e.g., RSTD measurement instance 1130) can be estimated without inter-anchor procedures. For example, under non-ideal synchronization assumptions for anchor A 1002 and mobile anchor B″ 1006, at time t3, the DL-TDOA algorithm for RSTD measurement instance 1130 may be written as follows:

[0210]

number

[0211]

[0187] Δ anchorSync,5 may be written as follows: Δ anchorSync,5 =Δ anchorSync,1 +(e B -e A )T PRS#1-to-#5 formula 15

[0212]

[0188] Thus, when measuring a set of RSTDs with a mobile anchor (mobile anchor B 1006) over time, only two RSTD measurement instances are required for clock drift error mitigation, shown in Figure 11 as RSTD measurement instances 1110 and 1120. One or more of the remaining RSTD measurement instances, shown in Figure 11 as RSTD measurement instance 1130, are not required to determine clock drift error mitigation and therefore do not require an inter-anchor procedure.

[0213]

[0189] It should be understood that the inter-anchor procedure for generating the RxTx time difference for two corresponding sets of PRS transmitted by anchor A1002 and mobile anchor B1006 can be measured by mobile anchor B1006 as shown in Figure 11 or can be measured by anchor A1002.

[0214] 12 shows, by way of example, an exemplary process 1200 for a TDOA procedure using time drift mitigation for a mobile anchor to improve positioning accuracy for position estimation of a target UE 104. The process 1200 shown in FIG. 12 is similar to the process 1100 shown in FIG. 11, except that, during an RSTD measurement instance 1210, τ between receiving PRS#1 from mobile anchor B 1006 (transmitted at time t1) and transmitting PRS#2 to the target UE 104 is increased. B,1 The RxTx time difference, marked as

[0215]

number

[0216] and in RSTD measurement instance 1220, τ between receiving PRS#3 from mobile anchor B′ 1006 (transmitted at time t) and transmitting PRS#4 to target UE 104 B’,3 The RxTx time difference, marked as

[0217]

number

[0218] , but the RxTx time difference does not need to be measured or reported in the RSTD measurement instance 1230.

[0219] Figure 13 is a diagram of reference signals (PRS) transmitted by anchor A 1002 and mobile anchor B 1006 to generate a set of RSTD measurements using clock drift error mitigation as discussed in Figure 11. The set of RSTD measurements generated for a target UE 104 over time may be defined with 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 pairs of PRS from the first PRS instance set 1302 and second PRS instance set 1304 generate RSTD measurement instances 1310, 1320, 1330, and 1340 identified by dashed boxes.

[0220] As discussed above, only two RSTD measurement instances are needed for clock drift error mitigation. Thus, for an RSTD set generated using mobile anchor B 1006, only two inter-anchor measurements are needed, i.e., for example, in a PRS pair in RSTD measurement instances 1310 and 1330, the RxTx time difference for two PRSs from the first PRS instance set 1302 of PRS from anchor A 1002 and the corresponding two PRSs from the second PRS instance set 1304 of PRS from mobile anchor B 1006 should be measured and reported (e.g., to a location server or target UE 104) by mobile anchor B 1006 or fixed anchor A 1002, as shown in FIG. 12 .

[0221]

[0193] The two PRS instances for the inter-anchor RxTx time difference measurement are determined by the difference in the RxTx time difference measurement (e.g.,

[0222]

number

[0223] ) should have the same RxTx timing error group (TEG) identity (ID) so that some additive group delay can be mitigated. Two PRSs transmitted by any one of two anchors in two PRS instances, e.g., PRS#1 and PRS#3 or PRS#2 and PRS#4 shown in FIG. 11 or FIG. 12, should have the same Tx TEG ID, so that the drift error can be assumed to increase linearly over time, e.g., without synchronization adjustment between PRS#1 and PRS#3 or between PRS#2 and PRS#4.

[0224] In some implementations, the set of RSTD measurements for the target UE 104, for example, as shown in FIG. 11 or 12, may be triggered by a network entity or by fixed anchor A 1002. The triggering may be based on a location request from the target UE 104 prior to triggering the set of RSTD measurements. The triggering message may indicate, for example, a first PRS instance set of PRS resources (the PRS instance set 1302 from anchor A 1002 in FIG. 13) and a second PRS instance set of PRS resources (the PRS instance set 1304 from mobile anchor B 1006 in FIG. 13) to be associated with the set of RSTD measurements. For example, in some implementations, the first PRS instance set of PRS resources from anchor A 1002 and the second PRS instance set of PRS resources from mobile anchor B 1006 selected for the PRS instance set of the RSTD measurements may have the same periodicity.

[0225] Furthermore, two RSTD measurement instances for the inter-anchor RxTx time difference measurements may be indicated in the triggering message. The two inter-anchor RxTx time difference measurements measured by mobile anchor B 1006 or anchor A 1002 may be reported to a location calculation entity, i.e., target UE 104 or location server 172 (e.g., LMF 270).

[0226]

[0196] PRS resources from mobile anchor B 1006 may be reserved. For example, a PRS instance set of PRS resources transmitted by mobile anchor B 1006 (PRS instance set 1304 in FIG. 13) may be reserved by a network entity or by fixed anchor A 1002. Furthermore, a PRS instance set of PRS resources transmitted by mobile anchor B 1006 (PRS instance set 1304 in FIG. 13) may have a lifetime, e.g., a periodicity number.

[0227] 14 is a message flow 1400 illustrating messaging between a location server 172, anchor A 1402, anchor B 1404, and a target UE 104 to support TDOA positioning of a UE using RSTD measurements from a mobile anchor, as discussed herein. The location server 172 may be, for example, an LMF 270. In one implementation, anchor A 1402 may be a fixed anchor A 1002, and anchor B 1404 may be a mobile anchor B 1006 that performs RxTx time difference measurements between the two anchors, as shown in FIG. 11. In another implementation, anchor A 1402 may be a mobile anchor B 1006 that performs RxTx time difference measurements between the two anchors, and anchor B 1404 may be a fixed anchor A 1002, as shown in FIG. 12. For ease of reference in Figure 14, anchor A 1402 is assumed to be a fixed anchor and anchor B 1406 is assumed to be a mobile anchor, but it should be understood that without loss of generality, anchor A 1402 may also be a mobile anchor and anchor B may also be a fixed anchor in Figure 14. While Figure 14 shows messages related to TDOA positioning of a target UE using RSTD measurements as discussed herein, it should be understood that additional or fewer messages, including traditional LPP messages, may be included in the message flow 1400. For example, messaging to establish a positioning session and determine the capabilities of the UE 104 may be exchanged, or no assistance data may be included.

[0228] In stage 1, the location server 172 may send assistance data to the UE 104, for example, in an LPP Assistance Data message. The assistance data may include PRS configuration information for the anchors 1402 and 1406 and may identify the fixed anchor 1402 and the mobile anchor 1406. The assistance data may further include the location of the fixed anchor, for example, for a UE-based positioning process. The location server 172 may provide PRS configuration information regarding PRS resources to be received by the target UE 104 from anchor A 1402 and anchor B 1406.

[0229] In stage 2, the location server 172 may send PRS configuration information to the anchors 1402 and 1406 to be transmitted to the target UE 104. The location server 172 may further provide PRS configuration information to anchor B 1406 regarding PRS resources to be transmitted by anchor A 1402 that should be detected by anchor B 1406. The location server 172 may, for example, indicate a PRS instance set of PRS resources to be transmitted by anchor A 1402 and a PRS instance set of resources to be transmitted by anchor B 1406 that should be associated with a set of RSTD measurements for the UE 104. The PRS instance sets of PRS resources may, for example, be selected to have the same periodicity. The location server 172 may indicate an RSTD measurement instance for inter-anchor RxTx time difference measurements by anchor B 1406. The PRSs in the inter-anchor RxTx time difference measurements may have the same RxTx TEG ID. Furthermore, the PRS transmitted by a stationary anchor entity, e.g., anchor A 1402 for RxTx time difference measurement between two anchors, may have the same Tx TEG ID, and / or the PRS transmitted by a mobile anchor entity, e.g., anchor B 1406 for RxTx time difference measurement between two anchors, may have the same Tx TEG ID. The PRS instance set of PRS resources to be transmitted by mobile anchor B 1406 may be reserved by a network entity, e.g., the location server 172, or by the fixed anchor A 1402. Furthermore, the PRS instance set of PRS resources transmitted by mobile anchor B 1406 may have a lifetime, e.g., a periodicity number. The PRS to be transmitted by mobile anchor B 1406 may be reserved by the fixed anchor A 1402. In some implementations, PRS configuration information may be sent by the fixed anchor A 1402 as opposed to the location server 172.

[0230] 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. The Location Information Request or another message may trigger, for example, a set of RSTD measurements for the target UE 104. In some implementations, a stationary anchor entity, for example, anchor A 1402, may send a trigger message to the target UE 104. The trigger request may be in response to a location request for the target UE 104. In some implementations, the triggering message, for example, a Location Information Request, may provide PRS resource information from the anchor entity regarding PRS resources to be measured for the set of RSTD measurements. The request may be, for example, for RSTD measurements for UE-assisted positioning or for location estimation (and optionally RSTD measurements) for UE-based positioning.

[0231] Blocks 1410, 1420, and 1430 show different RSTD measurement instances over time, during which the position of mobile anchor B 1406 changes relative to the target UE 104 and therefore mobile anchor B 1406 acts as multiple virtual anchors for the RSTD measurement instances. Mobile anchor B 1406 may perform and report inter-anchor RxTx time difference measurements at only two RSTD measurement instances, shown as RSTD 1410 and 1420, for clock drift error mitigation.

[0232] In stage 4 of 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 may be measured and reported and used in the RSTD measurement.

[0233]

[0203] In stage 5 of the RSTD measurement instance 1410, the anchor 1406 transmits a reference signal (eg, SL or DL ​​PRS) to the target UE 104.

[0234] In stage 6 of the RSTD measurement instance 1410, the anchor 1406 measures a 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 position in the RSTD measurement instance 1410, which may, for example, be determined from precise GNSS and / or ground measurements that coincide with the RSTD measurement instance 1410, or may be based on a previously determined precise position (e.g., GNSS and / or ground measurements) that is updated using sensor information, as discussed above, for example, in a dead reckoning procedure.

[0235] In step 7 of the RSTD measurement instance 1420, the anchor 1402 transmits a reference signal, e.g., (DL PRS), to the target UE 104 and the anchor 1406. As in step 4, 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 can be measured and reported and used in the RSTD measurement.

[0236]

[0206] In step 8 of the RSTD measurement instance 1420, the anchor 1406 transmits a reference signal (eg, SL or DL ​​PRS) to the target UE 104, similar to step 5.

[0237] In step 9 of the RSTD measurement instance 1420, the anchor 1406 measures a second RxTx time difference between receiving the PRS from the anchor 1402 in step 7 and transmitting the PRS to the target UE 104 in step 8. The anchor 1406 may further record the transmission time, T_tx, of the PRS transmitted to the target UE 104 in step 8. The anchor 1406 additionally records its position in the RSTD measurement instance 1420, which may be determined similarly to step 6, e.g., using GNSS and / or terrestrial measurements, or dead reckoning using precise GNSS and / or terrestrial measurements together with sensor information.

[0238] In step 10 of the RSTD measurement instance 1430, the anchor 1402 transmits a reference signal, e.g., (DL PRS), to the target UE 104. The PRS transmitted in step 10 does not need to be transmitted to or received by the anchor 1406.

[0239] In stage 11 of the RSTD measurement instance 1430, the anchor 1406 transmits a reference signal (e.g., an SL or DL ​​PRS) to the target UE 104, similar to stage 8. Unlike the RSTD measurement instances 1410 and 1420, in RSTD 1430, the anchor 1406 does not need to measure the RxTx time difference between receiving the PRS from the anchor 1402 and transmitting the PRS to the target UE 104 in stage 10. The anchor 1406 may further record the transmission time, T_tx, of the PRS transmitted to the target UE 104 in stage 11. However, similar to stage 6, the anchor 1406 may additionally record in the RSTD measurement instance 1430 its position which may be determined, for example, using GNSS and / or terrestrial measurements, or precise GNSS and / or terrestrial measurements with sensor information.

[0240] In step 12, the UE 104 performs location measurement using the DL PRS received from anchor A 1402 and anchor B 1406 in steps 4 and 5, steps 7 and 8, and steps 10 and 11. The location measurement may be calculated, for example, as a difference between the reception time Rx of the PRS from anchor A 1402 and the reception time of the PRS from anchor B 1404 at the target UE 104, e.g., τ UE,1 , τ UE,3 , and τ UE,5 For example, the time difference (T_Rx-Rx) or an indication of the number of receptions may be included, shown as

[0241] In stage 13, anchor B 1406 provides a measurement report to a location calculation entity, i.e., location server 172, or in some implementations (shown by the dotted line) target UE 104. The measurement report may include RxTx time difference measurements from RSTD measurement instances 1410 and 1420, the transmission times T_tx of the PRS transmitted in stages 5, 8, and 11, and (assuming anchor B 1406 is a mobile anchor) location information of anchor B 1406 (e.g., absolute position for each time instance, e.g., stages 5, 8, and 11).

[0242] In stage 14, anchor A 1402 provides a measurement report to a location calculation entity, i.e., location server 172, or in some implementations (shown by the dotted line) target UE 104. The measurement report may include the transmission time T_tx of the PRS transmitted in stages 4, 7, and 10. In some implementations, anchor A 1402 may provide its location if not provided in the assistance data in stage 1 (or if anchor A 1402 is a mobile anchor).

[0243] In step 15, as shown by the dotted box, in the case of UE-based positioning, the target UE 104 may use the positioning measurements performed as step 12 and the measurement reports received from anchor B 1406 and anchor A 1402 in steps 13 and 14 to generate a position estimate using TDOA as discussed herein. The target UE 104 may use, for example, the assistance data and the reported positions of the mobile anchors, e.g., the clock drift error (e B -e A ) and the time of flight T between anchor A 1402 and anchor B 1406 for each RSTD measurement instance 1410, 1420, 1430. oF , which may be determined using measurements from RSTD measurement instances 1410, 1420, and 1430 and the clock drift error (e B -e A ) may be used to determine the TDOA. For example, using the known locations of the anchors received in the assistance data in stage 1 and / or the determined TDOA, the position of the UE 104 may be estimated using multilateration.

[0244] In step 16, the UE 104 sends the location information in an LPP Provide Location Information message to the location server 172. The location information may include, for example, the determined position estimate from step 15 and / or the position measurement determined in step 12, e.g., an indication of the difference between the time of reception of the PRS from anchor A 1402 and the time of reception of the PRS from anchor 1406. For example, the location information may include the difference in the time of reception of the PRS, or the time of reception.

[0245] In step 17, the location server 172 may determine a position estimate for the target UE 104 or verify a position estimate from the UE 104 based on the location information received in the messages in steps 13, 14, and 16. The location server 172 may determine the position of the target UE 104 using TDOA, as discussed herein. The location server 172 may calculate the time of flight T between anchor A 1402 and anchor B 1406 for each RSTD measurement instance 1410, 1420, 1430 based on, for example, the known positions of the fixed anchors and the reported positions of the mobile anchors, for example, from step 13. oF and the clock drift error (e B -e A ) and measurements from RSTD measurement instances 1410, 1420, and 1430 and the clock drift error (e B -e A Using the known locations of the anchors and the determined TDOA, the position of the UE 104 may be estimated using multilateration.

[0246] 15 shows a flowchart of an example process 1500 for supporting operation of a location estimation entity to determine the location of a target UE. In one implementation, the process may be performed by a location server, such as the location server 172 shown in FIG. 1A or the LMF 270 or SLP 268 shown in FIG. 2B. In one implementation, the process may be performed by the target UE, such as the target UE 104 shown in FIG. 1A.

[0247] In block 1502, the position estimation entity may obtain a set of reference signal time difference (RSTD) measurements for the target UE, the RSTD measurement set 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 positioning reference signal (PRS) from a first PRS instance set transmitted by a stationary anchor entity and a corresponding PRS from a second PRS instance set transmitted by a mobile anchor entity, for example, as shown in Figures 10-13 and in step 12 or step 16 of Figure 14. The stationary anchor entity may be, for example, anchor A 1002 shown in Figures 10-13, or anchor A 1402 or anchor B 1406 in Figure 14. The mobile anchor entity may be, for example, mobile anchor B 1006 shown in Figures 10-13, or anchor A 1402 or anchor B 1406 in Figure 14.

[0023] Means for obtaining a set of reference signal time difference (RSTD) measurements for a target UE 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 positioning reference signal (PRS) from a first set of 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, may include at least one WWAN transceiver 310, or at least one short-range wireless transceiver 320, and at least one processor 332 with dedicated hardware or implementing executable code or software instructions in memory 340, such as a PRS module 342 in the UE 302 shown in FIG. 3A, or at least one network interface 390 and at least one processor 394 with dedicated hardware or implementing executable code or software instructions in memory 396, such as a PRS module 398 in the network entity 306 shown in FIG. 3C.

[0248]

[0218] In block 1504, the position estimation entity may obtain at least two anchor-to-anchor transmit / receive (RxTx) time difference measurements, each anchor-to-anchor RxTx time difference measurement being associated with a PRS from a first PRS instance set and a corresponding PRS from a second PRS instance set, and the number of anchor-to-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements, for example, as shown in Figures 10 to 13 and at steps 6, 9, and 13 of Figure 14. The means for obtaining at least two inter-anchor transmit / receive (RxTx) time difference measurements, where each inter-anchor RxTx time difference measurement is associated with a PRS from a first PRS instance set and a corresponding PRS from a second PRS instance set, and where the number of inter-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements, may include at least one WWAN transceiver 310 or at least one short-range wireless transceiver 320 and at least one processor 332 with dedicated hardware or implementing executable code or software instructions in memory 340, such as the PRS module 342 in the UE 302 shown in FIG. 3A, or at least one network interface 390 and at least one processor 394 with dedicated hardware or implementing executable code or software instructions in memory 396, such as the PRS module 398 in the network entity 306 shown in FIG. 3C.

[0249] In block 1506, the location estimation entity may determine a location estimate for the target UE based on the set of RSTD measurements and the at least two inter-anchor RxTx time difference measurements, for example, as shown in Figures 10-13 and at step 15 or step 17 of Figure 14. The means for determining a location estimate for the target UE based on the set of RSTD measurements and the at least two inter-anchor RxTx time difference measurements may include at least one WWAN transceiver 310 or at least one short-range wireless transceiver 320 and at least one processor 332 with dedicated hardware or implementing executable code or software instructions in memory 340, such as the PRS module 342 in the UE 302 shown in Figure 3A, or at least one network interface 390 and at least one processor 394 with dedicated hardware or implementing executable code or software instructions in memory 396, such as the PRS module 398 in the network entity 306 shown in Figure 3C.

[0250]

[0220] In one implementation, each inter-anchor RxTx time difference measurement is either a measurement performed by a mobile anchor entity based on the reception of a first PRS in a first PRS instance set and the transmission of a second PRS in a second PRS instance set, or a measurement performed by a stationary anchor entity based on the reception of a third PRS in a second PRS instance set and the transmission of a fourth PRS in the first PRS instance set, as discussed in Figures 11 and 12, respectively, and in Figure 14, including steps 6 and 9.

[0251]

[0221] In one implementation, a PRS from a first PRS instance set and a corresponding PRS from a second PRS instance set within at least two inter-anchor RxTx time difference measurements have the same RxTx timing error group identifier, for example, as discussed in stage 2 of Figures 13 and 14.

[0252]

[0222] In one implementation, the PRSs transmitted by the stationary anchor entity within the first PRS instance set associated with at least two inter-anchor RxTx time difference measurements have the same transmit timing error group identifier, for example, as discussed in stage 2 of Figures 13 and 14.

[0253]

[0223] In one implementation, the PRSs transmitted by the mobile anchor entity within the second PRS instance set associated with at least two inter-anchor RxTx time difference measurements have the same transmit timing error group identifier, for example, as discussed in stage 2 of Figures 13 and 14.

[0254] In one implementation, the set of RSTD measurements for the target UE is triggered by a location server or by a stationary anchor entity, e.g., as discussed in stage 3 of Figures 13 and 14. The set of RSTD measurements for the target UE may be triggered, e.g., based on a location request from the target UE, e.g., as discussed in stage 3 of Figures 13 and 14. A triggering message sent to the target UE to trigger a set of RSTD measurements for the target UE may indicate PRS resources in a first PRS instance set and a second PRS instance set, e.g., as discussed in stage 3 of Figures 13 and 14. The PRS resources in the first PRS instance set and the second PRS instance set may have the same periodicity, e.g., as discussed in stage 2 of Figures 13 and 14. The triggering message indicates PRS resources in the first PRS instance set for at least two inter-anchor RxTx time difference measurements, e.g., as discussed in stage 2 of Figures 13 and 14.

[0255]

[0225] In one implementation, the position estimation entity is a location server and at least two inter-anchor RxTx time difference measurements are received from one of a stationary anchor entity and a mobile anchor entity, for example, as discussed in steps 13 and 17 of Figure 14.

[0256]

[0226] In one implementation, the location estimation entity is a target UE and at least two inter-anchor RxTx time difference measurements are received from one of a stationary anchor entity and a mobile anchor entity, for example, as discussed in steps 13 and 15 of Figure 14.

[0257]

[0227] In one implementation, the PRSs in the second PRS instance set transmitted by the mobile anchor entity for the set of RSTD measurements are reserved by the stationary anchor entity, for example, as discussed in stage 2 of Figures 13 and 14.

[0258]

[0228] In one implementation, the PRSs in the second PRS instance set transmitted by the mobile anchor entity for a set of RSTD measurements have a restriction on the number of periods, for example, as discussed in stage 2 of Figures 13 and 14.

[0259] References throughout this specification to "one example," "an example," "particular example," or "exemplary implementation" mean that a particular feature, structure, or characteristic described in a feature and / or example may be included in at least one feature and / or example of the claimed subject matter. Thus, the appearances of the phrases "in one example," "an example," "particular example," or "in a particular implementation" or other similar phrases in various places throughout this specification are not necessarily all referring to the same features, examples, and / or limitations. Furthermore, particular features, structures, or characteristics may be combined in one or more examples and / or characteristics.

[0260] Some portions of the detailed descriptions contained herein are presented in terms of algorithms or symbolic representations of operations on binary digital signals stored within the memory of a particular apparatus or special-purpose computing device or platform. In the context of this particular specification, the term particular apparatus or the like includes a general-purpose computer that, when programmed, performs particular operations pursuant to instructions from program software. Algorithmic descriptions or symbolic representations are examples of techniques used by those skilled in the signal processing or related arts to convey the substance of their work to others skilled in the art. An algorithm, as used herein, is generally considered to be a self-consistent sequence of operations or similar signal processing leading to a desired result. In this context, operations or processing involve physical manipulation of physical quantities. Usually, though not necessarily, such quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, primarily for reasons of common usage, to refer to such signals as bits, data, values, elements, symbols, characters, terms, numbers, numerical values, or the like. However, it should be understood that all of these and similar terms are merely convenient labels and must be associated with the appropriate physical quantities. Unless otherwise expressly indicated, as will be apparent from the discussion herein, it will be understood that throughout this specification, discussions utilizing terms such as "processing," "calculating," "computing," "determining," etc. refer to the actions or processes of a particular apparatus, such as a special purpose computer, a special purpose computing apparatus, or a similar special purpose electronic computing device. Thus, in the context of this specification, a special purpose computer or similar special purpose electronic computing device is typically capable of manipulating or transforming signals that are represented as physical electronic or magnetic quantities within a memory, register, or other information storage, transmission, or display device of the special purpose computer or similar special purpose electronic computing device.

[0261]

[0231] In the above detailed description, numerous specific details are set forth to provide a thorough understanding of the claimed subject matter. However, it will be understood by those skilled in the art that the claimed subject matter can be practiced without these specific details. In other instances, methods and apparatuses that would be known by those skilled in the art have not been described in detail so as not to obscure the claimed subject matter.

[0262] As used herein, the terms "and," "or," and "and / or" can have a variety of meanings, which are expected to depend at least in part on the context in which such terms are used. Typically, when "or" is used to link a list such as A, B, or C, it is intended that it be used herein in the inclusive sense of A, B, and C, and herein in the exclusive sense of A, B, or C. Additionally, as used herein, the term "one or more" may be used to describe any feature, structure, or characteristic in singular, or it may be used to describe a plurality of features, structures, or characteristics, or some other combination of features, structures, or characteristics. However, it should be noted that this is merely an example and that claimed subject matter is not limited to this example.

[0263]

[0233] While what are presently considered to be exemplary features have been illustrated and described, it will be understood by those skilled in the art that various other modifications can be made and equivalents substituted without departing from the claimed subject matter. Additionally, many modifications may be made to adapt a particular situation to the teachings of the claimed subject matter without departing from the central concept described herein.

[0264]

[0234] In view of this description, embodiments may include various combinations of features. Example implementations are described in the following numbered clauses.

[0265]

[0235] Clause 1. A method for operating a location estimation entity to determine a location of a target user equipment (UE), the method comprising: acquiring a set of reference signal time difference (RSTD) measurements for the target UE, the set 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 positioning reference signal (PRS) instance set transmitted by a stationary anchor entity and a corresponding PRS from a second PRS instance set transmitted by a mobile anchor entity; acquiring at least two inter-anchor transmit / receive (RxTx) time difference measurements, wherein each inter-anchor RxTx time difference measurement is associated with a PRS from the first PRS instance set and a corresponding PRS from the second PRS instance set, and the number of inter-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements; and determining a location estimate for the target UE based on the set of RSTD measurements and the at least two inter-anchor RxTx time difference measurements.

[0266]

[0236] Clause 2. The method described in Clause 1, wherein each inter-anchor RxTx time difference measurement is either a measurement performed by a mobile anchor entity based on reception of a first PRS in a first PRS instance set and transmission of a second PRS in a second PRS instance set, or a measurement performed by a stationary anchor entity based on reception of a third PRS in a second PRS instance set and transmission of a fourth PRS in the first PRS instance set.

[0267]

[0237] Clause 3. The method of clause 1 or 2, wherein a PRS from a first PRS instance set and a corresponding PRS from a second PRS instance set in at least two inter-anchor RxTx time difference measurements have the same RxTx timing error group identifier.

[0268]

[0238] Clause 4. A method according to any one of clauses 1 to 3, wherein the PRSs transmitted by the stationary anchor entity within a first PRS instance set associated with at least two inter-anchor RxTx time difference measurements have the same transmission timing error group identifier.

[0269]

[0239] Clause 5. A method according to any one of clauses 1 to 4, wherein the PRSs transmitted by the mobile anchor entity within the second PRS instance set associated with at least two inter-anchor RxTx time difference measurements have the same transmission timing error group identifier.

[0270]

[0240] Clause 6. The method of any of clauses 1 to 5, wherein the set of RSTD measurements for the target UE is triggered by a location server or by a stationary anchor entity.

[0271]

[0241] 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.

[0272]

[0242] Clause 8. The method of clause 6 or 7, wherein a triggering message sent to the target UE to trigger a set of RSTD measurements for the target UE indicates PRS resources in the first PRS instance set and the second PRS instance set.

[0273]

[0243] Clause 9. The method of clause 8, wherein the PRS resources in the first PRS instance set and the second PRS instance set have the same periodicity.

[0274]

[0244] Clause 10. The method of any one of clauses 6 to 9, wherein the triggering message indicates PRS resources in a first PRS instance set for at least two inter-anchor RxTx time difference measurements.

[0275]

[0245] Clause 11. A method according to any one of clauses 1 to 10, wherein the position estimation entity is a location server and at least two inter-anchor RxTx time difference measurements are received from one of a stationary anchor entity and a mobile anchor entity.

[0276]

[0246] Clause 12. A method according to any one of clauses 1 to 10, wherein the location estimation entity is a target UE and at least two inter-anchor RxTx time difference measurements are received from one of a stationary anchor entity and a mobile anchor entity.

[0277]

[0247] Clause 13. The method of any of clauses 1 to 12, wherein a PRS in the second PRS instance set transmitted by the mobile anchor entity for the set of RSTD measurements is reserved by the stationary anchor entity.

[0278]

[0248] Clause 14. A method according to any one of clauses 1 to 13, wherein the PRS in the second PRS instance set transmitted by the mobile anchor entity for the set of RSTD measurements has a restriction on the number of periods.

[0279]

[0249] Clause 15. A location estimation entity configured to determine a location of a target user equipment (UE), comprising: a memory; at least one external interface; and at least one processor communicatively coupled to the memory and the at least one external interface, wherein the at least one processor is configured to generate a set of reference signal time difference (RSTD) measurements for the target UE, the set of RSTD measurements comprising at least three RSTD measurements generated by the target UE at different times, each RSTD measurement being a PRS from a first set of positioning reference signal (PRS) instances transmitted by a stationary anchor entity and a PRS from a second set of PRS instances transmitted by a mobile anchor entity. and a corresponding PRS from a first PRS instance set; acquire at least two inter-anchor transmit / receive (RxTx) time difference measurements, wherein each inter-anchor RxTx time difference measurement is associated with a PRS from a first PRS instance set and a corresponding PRS from a second PRS instance set, and the number of inter-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements; and determine a location estimate for the target UE based on the set of RSTD measurements and the at least two inter-anchor RxTx time difference measurements.

[0280]

[0250] Clause 16. A position estimation entity as described in Clause 15, wherein each inter-anchor RxTx time difference measurement is either a measurement performed by a mobile anchor entity based on reception of a first PRS in a first PRS instance set and transmission of a second PRS in a second PRS instance set, or a measurement performed by a stationary anchor entity based on reception of a third PRS in the second PRS instance set and transmission of a fourth PRS in the first PRS instance set.

[0281]

[0251] Clause 17. A position estimation entity as described in clause 15 or 16, wherein a PRS from a first PRS instance set and a corresponding PRS from a second PRS instance set within at least two inter-anchor RxTx time difference measurements have the same RxTx timing error group identifier.

[0282]

[0252] Clause 18. A position estimation entity described in any of clauses 15 to 17, wherein the PRSs transmitted by a stationary anchor entity within a first PRS instance set associated with at least two inter-anchor RxTx time difference measurements have the same transmission timing error group identifier.

[0283]

[0253] Clause 19. A location estimation entity described in any of clauses 15 to 18, wherein the PRS transmitted by the mobile anchor entity within the second PRS instance set associated with at least two inter-anchor RxTx time difference measurements have the same transmission timing error group identifier.

[0284]

[0254] Clause 20. A location estimation entity according to any of clauses 15 to 19, wherein the set of RSTD measurements for the target UE is triggered by a location server or by a stationary anchor entity.

[0285]

[0255] Clause 21. The location estimation entity of clause 20, wherein the set of RSTD measurements for the target UE is triggered based on a location request from the target UE.

[0286]

[0256] Clause 22. A location estimation entity as described in clause 20 or 21, wherein a triggering message sent to a target UE to trigger a set of RSTD measurements for the target UE indicates PRS resources in a first PRS instance set and a second PRS instance set.

[0287]

[0257] Clause 23. The position estimation entity of clause 22, wherein the PRS resources in the first PRS instance set and the second PRS instance set have the same periodicity.

[0288]

[0258] Clause 24. The location estimation entity of any of clauses 20 to 23, wherein the triggering message indicates PRS resources in a first PRS instance set for at least two inter-anchor RxTx time difference measurements.

[0289]

[0259] Clause 25. A position estimation entity described in any of clauses 15 to 24, wherein the position estimation entity is a location server, at least one external interface includes at least one network interface, and at least two inter-anchor RxTx time difference measurements are received from one of a stationary anchor entity and a mobile anchor entity.

[0290]

[0260] Clause 26. A location estimation entity described in any of clauses 15 to 24, wherein the location estimation entity is a target UE, at least one external interface includes at least one wireless transceiver, and at least two inter-anchor RxTx time difference measurements are received from one of a stationary anchor entity and a mobile anchor entity.

[0291]

[0261] Clause 27. A position estimation entity according to any of clauses 15 to 26, wherein a PRS in the second PRS instance set transmitted by the mobile anchor entity for the set of RSTD measurements is reserved by the stationary anchor entity.

[0292]

[0262] Clause 28. A position estimation entity according to any of clauses 15 to 27, wherein the PRS in the second PRS instance set transmitted by the mobile anchor entity for the set of RSTD measurements has a restriction on the number of periods.

[0293]

[0263] Clause 29. A location estimation entity configured to determine a location of a target user equipment (UE), comprising: means for acquiring a set of reference signal time difference (RSTD) measurements for the target UE, the set 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 positioning reference signal (PRS) instance set transmitted by a stationary anchor entity and a corresponding PRS from a second PRS instance set transmitted by a mobile anchor entity; means for acquiring at least two inter-anchor transmit / receive (RxTx) time difference measurements, wherein each inter-anchor RxTx time difference measurement is associated with a PRS from the first PRS instance set and a corresponding PRS from the second PRS instance set, and the number of inter-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements; and means for determining a location estimate for the target UE based on the set of RSTD measurements and the at least two inter-anchor RxTx time difference measurements.

[0294]

[0264] Clause 30. A position estimation entity as described in Clause 29, wherein each inter-anchor RxTx time difference measurement is either a measurement performed by a mobile anchor entity based on reception of a first PRS in a first PRS instance set and transmission of a second PRS in a second PRS instance set, or a measurement performed by a stationary anchor entity based on reception of a third PRS in the second PRS instance set and transmission of a fourth PRS in the first PRS instance set.

[0295]

[0265] Clause 31. A position estimation entity as described in clause 29 or 30, wherein a PRS from a first PRS instance set and a corresponding PRS from a second PRS instance set within at least two inter-anchor RxTx time difference measurements have the same RxTx timing error group identifier.

[0296]

[0266] Clause 32. A position estimation entity described in any of clauses 29 to 31, wherein the PRSs transmitted by a stationary anchor entity within a first PRS instance set associated with at least two inter-anchor RxTx time difference measurements have the same transmission timing error group identifier.

[0297]

[0267] Clause 33. A location estimation entity described in any of clauses 29 to 32, wherein the PRS transmitted by the mobile anchor entity within the second PRS instance set associated with at least two inter-anchor RxTx time difference measurements have the same transmission timing error group identifier.

[0298]

[0268] Clause 34. A location estimation entity according to any of clauses 29 to 33, wherein the set of RSTD measurements for the target UE is triggered by a location server or by a stationary anchor entity.

[0299]

[0269] Clause 35. The location estimation entity of clause 34, wherein the set of RSTD measurements for the target UE is triggered based on a location request from the target UE.

[0300]

[0270] Clause 36. A location estimation entity as described in clause 34 or 35, wherein a triggering message sent to a target UE to trigger a set of RSTD measurements for the target UE indicates PRS resources in a first PRS instance set and a second PRS instance set.

[0301]

[0271] Clause 37. The position estimation entity of clause 36, wherein the PRS resources in the first PRS instance set and the second PRS instance set have the same periodicity.

[0302]

[0272] Clause 38. The location estimation entity of any of clauses 34 to 37, wherein the triggering message indicates PRS resources in a first PRS instance set for at least two inter-anchor RxTx time difference measurements.

[0303]

[0273] Clause 39. A position estimation entity described in any of clauses 29 to 38, wherein the position estimation entity is a location server and at least two inter-anchor RxTx time difference measurements are received from one of a stationary anchor entity and a mobile anchor entity.

[0304]

[0274] Clause 40. A location estimation entity described in any of clauses 29 to 38, wherein the location estimation entity is a target UE and at least two inter-anchor RxTx time difference measurements are received from one of a stationary anchor entity and a mobile anchor entity.

[0305]

[0275] Clause 41. A position estimation entity according to any of clauses 29 to 40, wherein a PRS in the second PRS instance set transmitted by the mobile anchor entity for the set of RSTD measurements is reserved by the stationary anchor entity.

[0306]

[0276] Clause 42. A position estimation entity according to any of clauses 29 to 41, wherein the PRS in the second PRS instance set transmitted by the mobile anchor entity for the set of RSTD measurements has a restriction on the number of periods.

[0307]

[0277] Clause 43. A non-transitory storage medium having program code stored thereon, the program code operable to configure at least one processor in a position estimation entity to determine a position of a target user equipment (UE), the program comprising instructions for: a set of reference signal time difference (RSTD) measurements for the target UE comprising at least three RSTD measurements generated by the target UE at different times, each RSTD measurement in the set of RSTD measurements being a PRS from a first set of positioning reference signal (PRS) instances transmitted by a stationary anchor entity and a second PRS instance transmitted by a mobile anchor entity; and a corresponding PRS from a first PRS instance set; acquire at least two inter-anchor transmit / receive (RxTx) time difference measurements, wherein each inter-anchor RxTx time difference measurement is associated with a PRS from a first PRS instance set and a corresponding PRS from a second PRS instance set, and the number of inter-anchor RxTx time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements; and determine a location estimate for the target UE based on the set of RSTD measurements and the at least two inter-anchor RxTx time difference measurements.

[0308]

[0278] Clause 44. A non-transitory storage medium as described in Clause 43, wherein each inter-anchor RxTx time difference measurement is either a measurement performed by a mobile anchor entity based on reception of a first PRS in a first PRS instance set and transmission of a second PRS in a second PRS instance set, or a measurement performed by a stationary anchor entity based on reception of a third PRS in the second PRS instance set and transmission of a fourth PRS in the first PRS instance set.

[0309]

[0279] Clause 45. A non-transitory storage medium as described in clause 43 or 44, wherein a PRS from a first PRS instance set and a corresponding PRS from a second PRS instance set within at least two inter-anchor RxTx time difference measurements have the same RxTx timing error group identifier.

[0310]

[0280] Clause 46. A non-transitory storage medium described in any of clauses 43 to 45, wherein the PRSs transmitted by a stationary anchor entity within a first PRS instance set associated with at least two inter-anchor RxTx time difference measurements have the same transmission timing error group identifier.

[0311]

[0281] Clause 47. A non-transitory storage medium described in any of clauses 43 to 46, wherein the PRSs transmitted by the mobile anchor entity within the second PRS instance set associated with at least two inter-anchor RxTx time difference measurements have the same transmission timing error group identifier.

[0312]

[0282] Clause 48. A 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 a stationary anchor entity.

[0313]

[0283] Clause 49. The non-transitory storage medium of clause 48, wherein the set of RSTD measurements for the target UE is triggered based on a location request from the target UE.

[0314]

[0284] Clause 50. A non-transitory storage medium as described in clause 48 or 49, wherein a triggering message sent to a target UE to trigger a set of RSTD measurements for the target UE indicates PRS resources in a first PRS instance set and a second PRS instance set.

[0315]

[0285] Clause 51. The non-transitory storage medium of clause 50, wherein the PRS resources in the first PRS instance set and the second PRS instance set have the same periodicity.

[0316]

[0286] Clause 52. A non-transitory storage medium according to any one of clauses 48 to 51, wherein the triggering message indicates PRS resources in a first PRS instance set for at least two inter-anchor RxTx time difference measurements.

[0317]

[0287] Clause 53. A non-transitory storage medium described in any of clauses 43 to 52, wherein the position estimation entity is a location server and at least two inter-anchor RxTx time difference measurements are received from one of a stationary anchor entity and a mobile anchor entity.

[0318]

[0288] Clause 54. A non-transitory storage medium described in any of clauses 43 to 52, wherein the location estimation entity is a target UE and at least two inter-anchor RxTx time difference measurements are received from one of a stationary anchor entity and a mobile anchor entity.

[0319]

[0289] Clause 55. A non-transitory storage medium according to any one of clauses 43 to 54, wherein a PRS in the second PRS instance set transmitted by the mobile anchor entity for the set of RSTD measurements is reserved by the stationary anchor entity.

[0320]

[0290] Clause 56. A non-transitory storage medium according to any of clauses 43 to 55, wherein the PRS in the second PRS instance set transmitted by the mobile anchor entity for the set of RSTD measurements has a limitation on the number of periods.

[0321]

[0291] Accordingly, it is intended that the claimed subject matter not be limited to the particular examples disclosed, but that such claimed subject matter may include all aspects falling within the scope of the appended claims and equivalents thereof.

Claims

1. A method of operating a positioning entity to determine the position 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 comprising at least three RSTD measurements generated at different times by the target UE, wherein each RSTD measurement in the set of RSTD measurements is generated using a first positioning reference signal (PRS) instance set transmitted by a stationary anchor entity and a corresponding PRS from a second PRS instance set transmitted by a mobile anchor entity; obtaining at least two inter-anchor receive-transmit (RXTX) time difference measurements, wherein each inter-anchor RXTX time difference measurement is associated with the PRS from the first PRS instance set and the corresponding PRS from the second PRS instance set, and the number of inter-anchor RXTX time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements; determining an estimated position of the target UE based on the set of RSTD measurements and the at least two inter-anchor RXTX time difference measurements; A method comprising the steps of:

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

3. The method according to claim 1, wherein the PRS from the first PRS instance set and the corresponding PRS from the second PRS instance set in the at least two inter-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 within the first set of PRS instances associated with the RxTx time difference measurement values between the at least two anchors has the same transmission timing error group identifier.

5. The method according to claim 1, wherein the PRS transmitted by the mobile anchor entity within the second set of PRS instances associated with the RxTx time difference measurement values between the at least two anchors has the same transmission timing error group identifier.

6. The method according to claim 1, wherein the set of RSTD measurement values 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 measurement values for the target UE is triggered based on a location request from the target UE.

8. The method according to claim 6, wherein the triggering message sent to the target UE to trigger the set of RSTD measurement values for the target UE indicates the PRS resources within the first set of PRS instances and the second set of PRS instances.

9. The method according to claim 8, wherein the PRS resources within 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 triggering message indicates the PRS resources within the first set of PRS instances for the RxTx time difference measurement values between the at least two anchors.

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

12. The method according to claim 1, wherein the location estimation entity is the target UE, and the RxTx time difference measurement values between the at least two anchors 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 position estimation entity configured to determine the position of a target user equipment (UE), a memory, at least one external interface, at least one processor communicatively coupled to the memory and the at least one external interface, comprising, wherein the at least one processor obtains a set of RSTD measurements for the target UE, the set of RSTD measurements comprising at least three reference signal time difference (RSTD) measurements generated at different times by the target UE, wherein each RSTD measurement in the set of RSTD measurements is generated using a PRS from a first set of positioning reference signals (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. obtains at least two inter-anchor receive-transmit (R x T x) time difference measurements, wherein each inter-anchor R x T x 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 the number of inter-anchor R x T x time difference measurements is less than the number of RSTD measurements in the set of RSTD measurements. determines an estimated position of the target UE based on the set of RSTD measurements and the at least two inter-anchor R x T x time difference measurements. A position estimation entity configured to perform the above.

16. The RxTx time difference measurement between each anchor 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 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. The positioning entity according to claim 15, wherein the positioning entity is any one of the above.

17. The PRS from the first PRS instance set and the corresponding PRS from the second PRS instance set within the RxTx time difference measurement values between at least two anchors have the same RxTx timing error group identifier. The positioning entity according to claim 15.

18. The PRS transmitted by the stationary anchor entity within the first PRS instance set associated with the RxTx time difference measurement values between at least two anchors has the same transmission timing error group identifier. The positioning entity according to claim 15.

19. The PRS transmitted by the mobile anchor entity within the second PRS instance set associated with the RxTx time difference measurement values between at least two anchors has the same transmission timing error group identifier. The positioning entity according to claim 15.

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

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

22. The triggering message sent to the target UE to trigger the set of RSTD measurement values for the target UE indicates the PRS resources in the first PRS instance set and the second PRS instance set. The positioning entity according to claim 20.

23. The position 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 position estimation entity according to claim 20, wherein the triggering message indicates PRS resources in the first PRS instance set for the at least two anchor - to - anchor RxTx time difference measurement values.

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

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

27. The position estimation entity according to claim 15, wherein the PRS in the second PRS instance set transmitted by the mobile anchor entity for the set of RSTD measurement values is reserved by the stationary anchor entity.

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

29. A position estimation entity configured to determine the position of a target user equipment (UE), Means for obtaining a set of reference signal time difference (RSTD) measurement values for the target UE, comprising at least three RSTD measurement values generated at different times by the target UE, wherein each RSTD measurement value in the set of RSTD measurement values 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 (RxTx) time difference measurement values, wherein each anchor-to-anchor RxTx time difference measurement value is associated with the PRS from the first set of PRS instances and the corresponding PRS from the second set of PRS instances, and the number of anchor-to-anchor RxTx time difference measurement values is less than the number of RSTD measurement values in the set of RSTD measurement values. Means for determining an estimated position of the target UE based on the set of RSTD measurement values and the at least two anchor-to-anchor RxTx time difference measurement values. A position estimation entity comprising the above.

30. A non-transitory storage medium containing program code stored thereon, the program code being operable to configure at least one processor in a position estimation entity to determine the positioning of a target user equipment (UE), the program comprising instructions. Obtain a set of RSTD measurement values for the target UE, comprising at least three RSTD measurement values generated at different times by the target UE, wherein each RSTD measurement value in the set of RSTD measurement values 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 inter-anchor round-trip (RxTx) time difference measurement values, where each inter-anchor RxTx time difference measurement value is associated with the PRS from the first PRS instance set and the corresponding PRS from the second PRS instance set, and the number of inter-anchor RxTx time difference measurement values is less than the number of RSTD measurement values in the set of RSTD measurement values, Based on the set of RSTD measurement values and the at least two inter-anchor RxTx time difference measurement values, determine an estimated position value of the target UE, A non-transitory storage medium comprising instructions for.

Images