FFT window adjustment based on prs peak processing

Abstract

A user equipment (UE) associated with a wireless network determines a first reference signal time difference value. The UE determines a first RSTD estimate and a first RSTD uncertainty associated with the first RSTD value, identifies a search interval for the first RSTD value, the search interval extending from a difference between the first RSTD estimate and the first RSTD uncertainty to a sum of the first RSTD estimate and the first RSTD uncertainty, receives wireless signals during the identified search interval, determines a fast Fourier transform (FFT) window offset for decoding a first positioning reference signal (PRS) received during the identified search interval, and determines the first RSTD value based at least in part on the determined FFT window offset.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of Greek patent application No. 20210100014, filed on January 8, 2021, which is incorporated herein by reference in its entirety.

[0003] background

[0004] field :

[0005] The subject matter disclosed in this article relates to determining the Reference Signal Time Difference (RSTD) value in user equipment (UE) associated with a wireless network.

[0006] information :

[0007] Location information for mobile devices (such as cellular phones) can be useful or essential for several applications, including emergency calls, navigation, direction finding, consumer asset tracking, and internet services. The location of a mobile device can be estimated based on information collected from various systems. For example, in cellular networks implemented using 4G (also known as fourth-generation) Long Term Evolution (LTE) radio access or 5G (also known as fifth-generation) “New Radio” (NR), base stations can transmit a Position Reference Signal (PRS). Sending auxiliary data to the mobile device to assist in acquiring and measuring signals and / or calculating location estimates from these measurements can be useful for obtaining the PRS for location determination. Mobile devices that require PRS transmitted by different base stations can deliver signal-based measurements to a location server (which may be part of an Evolved Packet Core (EPC) or a 5G Core Network (5GCN)) for use in calculating the location estimate of that mobile device. For example, the UE can generate positioning measurements (such as Reference Signal Time Difference (RSTD), Reference Signal Received Power (RSRP), and Receive-to-Transmit (RX-TX) Time Difference measurements) based on the downlink (DL) PRS. These positioning measurements can be used for various positioning methods (such as Time Difference of Arrival (TDOA), Angle of Departure (AOD), and Multi-Cell Round-Trip Time (RTT)).

[0008] Positioning reference signals (PRS) are transmitted, for example, during periodically or dynamically assigned positioning times. Reception of such PRS can be impaired in the presence of channel noise or interference. Therefore, improving reception of such PRS would be desirable.

[0009] Overview

[0010] The user equipment (UE) determines the Reference Signal Time Difference (RSTD) for the received Positioning Reference Signal (PRS) without binding the Fast Fourier Transform (FFT) window used to receive the PRS to the serving cell symbol timing. The UE can determine a search interval for the RSTD value, which depends only on the expected value of the RSTD and the associated uncertainty of the RSTD value. The UE can then determine the FFT window offset for decoding the PRS received during that search interval and determine the RSTD value based on the determined FFT window offset.

[0011] In one implementation, a method for supporting localization of a user equipment (UE) in a wireless network is disclosed. The method may include determining a first RSTD estimate and a first RSTD uncertainty associated with the first RSTD value; identifying a search interval for the first RSTD value extending from the difference between the first RSTD estimate and the first RSTD uncertainty to the sum of the first RSTD estimate and the first RSTD uncertainty; receiving a radio signal during the identified search interval; determining a Fast Fourier Transform (FFT) window offset for decoding a first Positioning Reference Signal (PRS) received during the identified search interval; and determining the first RSTD value based at least in part on the determined FFT window offset.

[0012] In one implementation, a user equipment (UE) configured to determine a first RSTD value is disclosed, wherein the UE is associated with a wireless network and includes a wireless transceiver configured to wirelessly communicate with entities in the wireless network, at least one memory, and at least one processor coupled to the wireless transceiver and the at least one memory. The at least one processor is configured to: determine a first RSTD estimate and a first RSTD uncertainty associated with the first RSTD value; identify a search interval for the first RSTD value, wherein the search interval extends from the difference between the first RSTD estimate and the first RSTD uncertainty to the sum of the first RSTD estimate and the first RSTD uncertainty; receive a wireless signal during the identified search interval; determine an FFT window offset for decoding a first PRS received during the identified search interval; and determine the first RSTD value based at least in part on the determined FFT window offset.

[0013] In one implementation, a non-transient computer-readable storage medium is disclosed storing instructions executable by one or more processors of a UE associated with a wireless network. Execution of the instructions causes the UE to perform operations including determining a first RSTD estimate and a first RSTD uncertainty associated with the first RSTD value, identifying a search interval for the first RSTD value extending from the difference between the first RSTD estimate and the first RSTD uncertainty to the sum of the first RSTD estimate and the first RSTD uncertainty, receiving a wireless signal during the identified search interval, determining a Fast Fourier Transform (FFT) window offset for decoding a first Positioning Reference Signal (PRS) received during the identified search interval, and determining the first RSTD value based at least in part on the determined FFT window offset.

[0014] Other objectives and advantages associated with the aspects disclosed herein will be apparent to those skilled in the art based on the accompanying drawings and detailed description. Brief description of the attached diagram

[0016] The accompanying drawings are provided to help describe various aspects of this disclosure, and the drawings are provided for illustrative purposes only and not for limiting the aspects.

[0017] Figure 1 Exemplary wireless communication systems according to various aspects of this disclosure are explained.

[0018] Figure 2A and 2B Example wireless network architectures based on various aspects of this disclosure are explained.

[0019] Figure 3 The explanation can be Figure 1 A block diagram of the design of one of the base stations and one of the user equipment (UE) in the system.

[0020] Figure 4 The structure of an exemplary system for determining the size of a reference signal time difference (RSTD) search window according to various aspects of this disclosure is shown.

[0021] Figure 5 The standard set of PRS timing assumptions is shown.

[0022] Figure 6 Visually explain the relationship between signal-to-noise ratio (SNR) and PRS symbol timing relative to the serving cell boundary.

[0023] Figure 7 A depiction of RSTD determination and PRS timing assumptions according to various aspects of this disclosure is shown.

[0024] Figure 8 A schematic block diagram illustrating certain exemplary features of a UE implemented to support the determination of RSTD values ​​according to various aspects of this disclosure is shown.

[0025] Figure 9 A flowchart is shown of an exemplary method performed by a UE in a wireless network to support the location of the UE.

[0026] Detailed description

[0027] Various aspects of this disclosure are provided below in the description and accompanying drawings of various examples provided for illustrative purposes. Alternative aspects may be designed without departing from the scope of this disclosure. Furthermore, elements well-known in this disclosure will not be described in detail or will be omitted so as not to obscure the relevant details of this disclosure.

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

[0029] Those skilled in the art will appreciate that the information and signals described below can be represented using any of a variety of different techniques and arts. For example, the data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the following description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof, depending in part on the specific application, in part on the desired design, in part on the corresponding technology, etc.

[0030] Furthermore, many aspects are described in the form of sequences of actions performed by elements of, for example, computing devices. It will be appreciated that the various actions described herein can be performed by special-purpose circuitry (e.g., application-specific integrated circuits (ASICs)), by program instructions being executed by one or more processors, or by a combination of both. Additionally, the sequences of actions described herein can be considered to be fully embodied in any form of non-transient computer-readable storage medium storing a corresponding set of computer instructions that, upon execution, will cause an associated processor of the device to perform the functions described herein. Thus, various aspects of this disclosure can be embodied in several different forms, all of which are contemplated to fall within the scope of the claimed subject matter. Furthermore, for each aspect described herein, a corresponding form of any such aspect may be described herein as, for example, "logic configured to perform the described actions."

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

[0032] A base station may operate according to one of several RATs when communicating with a UE, depending on the network in which it is deployed, and may be alternatively referred to as an Access Point (AP), Network Node, B-Node, Evolved B-Node (eNB), New Radio (NR) B-Node (also known as gNB), etc. Additionally, in some systems, the base station may provide purely edge node signaling functions, while in others, it may provide additional control and / or network management functions. The communication link through which the UE can signal to the base station is called an uplink (UL) channel (e.g., reverse traffic channel, reverse control channel, access channel, etc.). The communication link through which the base station can signal to the UE is called a downlink (DL) or forward link channel (e.g., paging channel, control channel, broadcast channel, forward traffic channel, etc.). As used herein, the term traffic channel (TCH) may refer to either a UL / reverse or DL / forward traffic channel.

[0033] The term "base station" can refer to a single physical transmission point or multiple physical transmission points that may or may not be located in the same place. For example, when the term "base station" refers to a single physical transmission point, the physical transmission point may be a base station antenna corresponding to a cell of the base station. When the term "base station" refers to multiple physical transmission points located in the same place, these physical transmission points may be the antenna array of the base station (e.g., as in a multiple-input multiple-output (MIMO) system or where the base station employs beamforming). When the term "base station" refers to multiple physical transmission points not located in the same place, these physical transmission points may be a distributed antenna system (DAS) (a network of spatially separated antennas connected to a common source via a transmission medium) or a remote radio headend (RRH) (a remote base station connected to a serving base station). Alternatively, physical transmission points not located in the same place may be the serving base station from which the UE receives measurement reports and neighboring base stations from which the UE is measuring its reference radio frequency (RF) signal.

[0034] To support UE location, two main categories of location solutions have been defined: control plane and user plane. Using control plane (CP) location, location-related and location support signaling can be carried over existing network (and UE) interfaces using existing protocols dedicated to signaling transmission. Using user plane (UP) location, location-related and location support signaling can be carried using protocols such as Internet Protocol (IP), Transmission Control Protocol (TCP), and User Datagram Protocol (UDP) as part of other data.

[0035] The 3rd Generation Partnership Project (3GPP) has defined control plane location solutions for UEs using radio access based on GSM (2G), UMTS (3G), LTE (4G), and New Radio (NR) for 5G. These solutions are defined in 3GPP Technical Specifications (TS) 23.271 and 23.273 (common parts), 43.059 (GSM access), 25.305 (UMTS access), 36.305 (LTE access), and 38.305 (NR access). The Open Mobility Alliance (OMA) similarly defines an up-plane location solution called Secure User Plane Location (SUPL), which can be used to locate UEs accessing any of several radio interfaces supporting IP packet access, such as General Packet Radio Service (GPRS) in GSM, GPRS in UMTS, or IP access in LTE or NR.

[0036] Both CP and UP location solutions can employ location servers to support positioning. A location server can be part of or accessible from the UE's serving or home network, or it can be simply accessed via the Internet or a local intranet. If positioning of a UE is required, the location server can initiate a session with the UE (e.g., a location session or SUPL session) and coordinate location measurements performed by the UE and the determination of the estimated location for the UE. During a location session, the location server can request positioning capabilities from the UE (or the UE can provide these capabilities without request), provide auxiliary data to the UE (e.g., upon request by the UE or without request), and request location estimates or measurements from the UE for use with various positioning techniques (e.g., for Global Navigation Satellite System (GNSS), Time Difference of Arrival (TDOA), Angle of Departure (AOD), Round Trip Time (RTT), or Multi-Cell RTT (Multi-RTT) and / or Enhanced Cellular ID (ECID) positioning methods). Auxiliary data can be used by the UE to acquire and measure GNSS and / or PRS signals (e.g., by providing expected characteristics of these signals such as frequency, expected time of arrival, signal coding, and signal Doppler).

[0037] In UE-based operating modes, auxiliary data may be used by the UE, either additionally or alternatively, to help determine the location estimate from the resulting location measurement (e.g., providing satellite ephemeris data in the case of GNSS positioning or providing base station location and other base station characteristics (such as PRS timing) in the case of ground positioning using, for example, TDOA, AoD, Multi-RTT, etc).

[0038] In UE-assisted operation mode, the UE can return location measurements to a location server, which can determine the UE's estimated location based on these measurements and possibly also on other known or configured data (e.g., satellite ephemeris data for GNSS positioning or base station characteristics (including base station location and possible PRS timing) in the case of ground positioning using methods such as TDOA, AoD, multi-RTT, etc.).

[0039] In the case of a 3GPP CP location, the location server may be an Enhanced Serving Mobile Location Center (E-SMLC) for LTE access, a Self-reliant SMLC (SAS) for UMTS access, a Serving Mobile Location Center (SMLC) for GSM access, or a Location Management Function (LMF) for 5G NR access. In the case of an OMASUPL location, the location server may be a SUPL Location Platform (SLP), which may act as any of the following: (i) a Home SLP (H-SLP) (in the case of being in or associated with the UE's home network, or in the case of providing a permanent subscription for location services to the UE); (ii) a Discovered SLP (D-SLP) (in the case of being in or associated with some other (non-home) network, or in the case of not being associated with any network); (iii) an Emergency SLP (E-SLP) (in the case of supporting locations for emergency calls initiated by the UE); or (iv) a Visited SLP (V-SLP) (in the case of being in or associated with the UE's serving network or current local area).

[0040] During a location session, the location server and the UE can exchange messages defined according to a location protocol to coordinate the determination of the estimated location. Possible location protocols may include, for example, the LTE Location Protocol (LPP) defined by 3GPP in 3GPP TS 36.355 and the LPP Extensions (LPPe) protocols defined by OMA in OMA TS OMA-TS-LPPe-V1_0, OMA-TS-LPPe-V1_1, and OMA-TS-LPPe-V2_0. LPP and LPPe protocols can be used in combination, where an LPP message contains an embedded LPPe message. The combined LPP and LPPe protocols may be referred to as LPP / LPPe. LPP and LPP / LPPe can be used to help support 3GPP control plane solutions for LTE or NR access, in which case LPP or LPP / LPPe messages are exchanged between the UE and the E-SMLC or between the UE and the LMF. LPP or LPPe messages can be exchanged between the UE and the E-SMLC via the UE's Serving Mobility Management Entity (MME) and the Serving Evolved B-Node. LPP or LPPe messages can also be exchanged between the UE and the LMF via the UE's Serving Access and Mobility Management Function (AMF) and Serving NR B-Node (gNB). LPP and LPP / LPPe can also be used to help support OMASUPL solutions for many types of radio access that support IP messaging, such as LTE, NR, and WiFi, where LPP or LPP / LPPe messages are exchanged between the SUPL-enabled terminal (SET) (SET is the term used for the UE in SUPL) and the SLP, and can be transmitted within SUPL messages such as SUPL POS or SUPL POS INIT messages.

[0041] Location servers and base stations (e.g., evolved B-nodes for LTE access) can exchange messages enabling the location server to: (i) obtain location measurements for a specific UE from the base station, or (ii) obtain parameters of location information (such as the location coordinates of the base station's antennas), the cells supported by the base station (e.g., cell identity), the base station's cell timing, and / or signals transmitted by the base station (such as PRS signals) that are not associated with a specific UE. In the case of LTE access, the LPP A (LPPa) protocol can be used to transmit such messages between the base station acting as an evolved B-node and the location server acting as an E-SMLC. In the case of NR access, the NRPPA protocol can be used to transmit such messages between the base station acting as a gigabit node and the location server acting as an LMF. Note that the terms "parameter" and "information element" (IE) are synonyms and are used interchangeably herein.

[0042] During positioning using signaling in LTE and 5G NR, the UE typically acquires a dedicated positioning signal (referred to as the Positioning Reference Signal (PRS)) transmitted by the base station. This dedicated PRS is used to generate desired measurements for the supported positioning technologies. The Positioning Reference Signal (PRS) is defined for 5G NR positioning, enabling the UE to detect and measure more neighboring base stations or Transport and Receive Points (TRPs). Several configurations are supported to enable various deployments (indoor, outdoor, sub-6, mmW). To support PRS beaming operation, beam sweeping against the PRS is additionally supported. Table 1 below explains the 3GPP version numbers (e.g., version 16 or version 15) that define the specific reference signals used for various UE measurements and accompanying positioning technologies.

[0043]

[0044]

[0045] Table 1

[0046] Figure 1 An exemplary wireless communication system 100 has been described. The wireless communication system 100 (also referred to as a wireless wide area network (WWAN)) may include various base stations 102 and various UEs 104. Base station 102 may include macrocell base stations (high-power cellular base stations) and / or small cell base stations (low-power cellular base stations). In one aspect, the macrocell base station may include an eNB (where the wireless communication system 100 corresponds to an LTE network), or a gNB (where the wireless communication system 100 corresponds to a 5G network), or a combination of both, and the small cell base station may include femtocells, picocells, microcells, etc.

[0047] Each base station 102 can collectively form a RAN and interface with a core network 170 (e.g., an evolved packet core (EPC) or next-generation core (NGC)) via a backhaul link 122, and interface with one or more location servers 172 via the core network 170. Among other functions, base station 102 can also perform functions related to one or more of the following: transmitting user data, radio channel cryptography and decoding, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment tracking, RAN information management (RIM), paging, location, and delivery of alarm messages. Base stations 102 can communicate with each other directly or indirectly (e.g., via EPC / NGC) on a backhaul link 134, which can be wired or wireless.

[0048] Base station 102 can wirelessly communicate with UE 104. Each base station 102 can provide communication coverage for its respective geographical coverage area 110. In one aspect, one or more cells can be supported by base station 102 in each coverage area 110. A “cell” is a logical communication entity used to communicate with a base station (e.g., on a frequency resource, it is referred to as a carrier frequency, component carrier, carrier, frequency band, etc.) and can be associated with an identifier (e.g., Physical Cell Identifier (PCID), Virtual Cell Identifier (VCID)) to distinguish cells operating via the same or different carrier frequencies. In some cases, different cells can be configured according to different protocol types that can provide access for different types of UEs (e.g., Machine Type Communication (MTC), Narrowband IoT (NB-IoT), Enhanced Mobile Broadband (eMBB), or others). In some cases, the term “cell” can also refer to a geographical coverage area (e.g., a sector) of a base station in the sense that a carrier frequency can be detected and used for communication within a portion of the geographical coverage area 110.

[0049] While the geographic coverage areas 110 of adjacent macrocell base stations 102 may partially overlap (e.g., in handover areas), some geographic coverage areas 110 may substantially overlap with larger geographic coverage areas 110. For example, a small cell base station 102' may have a coverage area 110' that substantially overlaps with the coverage areas 110 of one or more macrocell base stations 102. A network that includes both small cell and macrocell base stations may be referred to as a heterogeneous network. A heterogeneous network may also include home eNBs (HeNBs) that provide service to a restricted group known as a Closed Subscriber Group (CSG).

[0050] The communication link 120 between base station 102 and UE 104 may include downlink (UL) transmission from UE 104 to base station 102 (also known as the reverse link) and / or downlink (DL) transmission from base station 102 to UE 104 (also known as the forward link). The communication link 120 may use MIMO antenna technologies, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link 120 may use one or more carrier frequencies. Carrier allocation may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated to DL compared to UL).

[0051] The wireless communication system 100 may further include a wireless local area network (WLAN) access point (AP) 150 communicating with a WLAN station (STA) 152 via a communication link 154 in unlicensed spectrum (e.g., 5 GHz). When communicating in unlicensed spectrum, the WLAN STA 152 and / or WLAN AP 150 may perform a clear channel assessment (CCA) to determine channel availability before communication.

[0052] Small cell base station 102' can operate in licensed and / or unlicensed spectrum. When operating in unlicensed spectrum, small cell base station 102' can employ LTE or 5G technology and use the same 5GHz unlicensed spectrum as used by WLAN AP 150. Small cell base station 102' employing LTE / 5G in unlicensed spectrum can enhance access network coverage and / or increase access network capacity. LTE in unlicensed spectrum may be referred to as LTE Unlicensed (LTE-U), Licensed Assisted Access (LAA), or MulteFire.

[0053] The wireless communication system 100 may further include a millimeter-wave (mmW) base station 180, which can operate in mmW and / or near-mmW frequencies to communicate with the UE 182. Extremely high frequency (EHF) is a portion of the electromagnetic spectrum that contains radio frequency (RF). EHF has a range of 30 GHz to 300 GHz and wavelengths between 1 mm and 10 mm. Radio waves in this band are referred to as millimeter waves. Near-mmW extends down to a 3 GHz frequency with a 100 mm wavelength. Ultra-high frequency (SHF) bands extend between 3 GHz and 30 GHz, and are also referred to as centimeter waves. Communication using mmW / near-mmW RF bands has high path loss and relatively short range. The mmW base station 180 and the UE 182 can utilize beamforming (transmit and / or receive) on the mmW communication link 184 to compensate for the extremely high path loss and short range. Furthermore, it will be appreciated that in alternative configurations, one or more base stations 102 may also use mmW or near-mmW and beamforming for transmission. Accordingly, it will be understood that the foregoing explanations are merely illustrative and should not be construed as limiting the aspects disclosed herein.

[0054] Transmit beamforming is a technique for focusing RF signals in a specific direction. Conventionally, when a network node (e.g., a base station) broadcasts an RF signal, it broadcasts the signal in all directions (omnidirectionally). Using transmit beamforming, the network node determines where a given target device (e.g., a UE) is located (relative to the transmitting network node) and projects a stronger downlink RF signal in that specific direction, thus providing the receiving device with a faster (in terms of data rate) and stronger RF signal. To change the directivity of the RF signal during transmission, the network node can control the phase and relative amplitude of the RF signal at each of one or more transmitters broadcasting the RF signal. For example, the network node can use an antenna array (referred to as a "phased array" or "antenna array") that generates a beam of RF waves, which can be "guided" to different directions without actually moving the antennas. Specifically, RF currents from the transmitters are fed to the individual antennas with the correct phase relationship so that radio waves from the separate antennas add together in the desired direction to increase radiation, while simultaneously canceling each other out in the undesired direction to suppress radiation.

[0055] In receive beamforming, a receiver uses a receive beam to amplify an RF signal detected on a given channel. For example, a receiver may increase the gain setting of an antenna array and / or adjust the phase setting of the antenna array in a specific direction to amplify the RF signal received from that direction (e.g., increase its gain level). Thus, when a receiver is referred to as beamforming in a certain direction, it means that the beam gain in that direction is higher than the beam gain in other directions, or that the beam gain in that direction is the highest compared to the beam gain of all other receive beams available to the receiver in that direction. This results in a stronger received signal strength (e.g., Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Signal-to-Interference-plus-Noise Ratio (SINR), etc.) of the RF signal received from that direction.

[0056] In 5G, the spectrum in which radio nodes (e.g., base stations 102 / 180, UE 104 / 182) operate is divided into several frequency ranges: FR1 (from 450 to 6000 MHz), FR2 (from 24250 to 52600 MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). In multi-carrier systems (such as 5G), one of the carrier frequencies is called the “primary carrier” or “anchor carrier” or “primary serving cell” or “PCell,” and the remaining carrier frequencies are called “secondary carriers” or “secondary serving cells” or “SCell.” In carrier aggregation, the anchor carrier is the carrier operating on the primary frequency (e.g., FR1) utilized by UE 104 / 182 and on the cell in which UE 104 / 182 performs an initial radio resource control (RRC) connection establishment procedure or initiates an RRC connection re-establishment procedure. The primary carrier carries all shared and UE-specific control channels. A secondary carrier is a carrier operating on a second frequency (e.g., FR2). This carrier can be configured once an RRC connection is established between UE 104 and the anchor carrier, and it can be used to provide additional radio resources. The secondary carrier may contain only the necessary signaling information and signals; for example, UE-specific signaling information and signals may not be present in the secondary carrier, as both the primary uplink and downlink carriers are typically UE-specific. This means that different UEs 104 / 182 within a cell can have different downlink primary carriers. The same applies to the uplink primary carrier. The network can change the primary carrier of any UE 104 / 182 at any time. For example, this is done to balance the load on different carriers. Since a “serving cell” (whether PCell or SCell) corresponds to the carrier frequency / component carrier that a base station is using for communication, the terms “cell,” “serving cell,” “component carrier,” “carrier frequency,” etc., can be used interchangeably.

[0057] For example, still refer to Figure 1 One of the frequencies utilized by the macrocell base station 102 can be an anchor carrier (or "PCell"), and other frequencies utilized by the macrocell base station 102 and / or mmW base station 180 can be secondary carriers ("SCell"). Simultaneous transmission and / or reception on multiple carriers allows the UE 104 / 182 to significantly increase its data transmission and / or reception rates. For example, two 20MHz aggregated carriers in a multi-carrier system would theoretically result in twice the data rate (i.e., 40MHz) compared to the data rate obtained from a single 20MHz carrier.

[0058] The wireless communication system 100 may further include one or more UEs (such as UE 190) that are indirectly connected to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links. Figure 1 In the example, UE190 has a D2D P2P link 192 with a UE 104 connected to a base station 102 (e.g., through which UE 190 indirectly obtains cellular connectivity), and a D2D P2P link 194 with a WLAN STA 152 connected to a WLAN AP 150 (through which UE190 indirectly obtains WLAN-based Internet connectivity). In one example, D2D P2P links 192 and 194 can use any known D2D RAT (such as LTE Direct (LTE-D), WiFi Direct (WiFi-D)). (etc.) to support.

[0059] The wireless communication system 100 may further include a UE 164, which can communicate with the macrocell base station 102 on the communication link 120 and / or with the mmW base station 180 on the mmW communication link 184. For example, the macrocell base station 102 may support PCell and one or more SCells for the UE 164, and the mmW base station 180 may support one or more SCells for the UE 164.

[0060] Figure 2A Example wireless network architecture 200 is explained. For example, NGC 210 (also referred to as "5GC") can be functionally considered as control plane functions 214 (e.g., UE registration, authentication, network access, gateway selection, etc.) and user plane functions 212 (e.g., UE gateway functions, access to data networks, IP routing, etc.), which operate collaboratively to form the core network. User plane interface (NG-U) 213 and control plane interface (NG-C) 215 connect gNB 222 to NGC 210, specifically to control plane functions 214 and user plane functions 212. In an additional configuration, eNB 224 can also connect to NGC 210 via NG-C 215 to control plane function 214 and NG-U 213 to user plane function 212. Furthermore, eNB 224 can communicate directly with gNB 222 via backhaul connection 223. In some configurations, the new RAN 220 may have only one or more gNBs 222, while other configurations include both one or more eNBs 224 and one or more gNBs 222. The gNB 222 or eNB 224 may be used with UE 204 (e.g., Figure 1The UE 204 may communicate with any UE depicted herein. Another optional aspect may include one or more location servers 230a, 230b (sometimes collectively referred to as location server 230) (which may correspond to location server 172), which may communicate with control plane function 214 and user plane function 212 in NGC 210, respectively, to provide location assistance to UE 204. Location server 230 may be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules extending across multiple physical servers, etc.), or alternatively, each may correspond to a single server. Location server 230 may be configured to support one or more location services for UE 204, which UE 204 can connect to via the core network, NGC 210, and / or via the Internet (not described). Furthermore, location server 230 may be integrated into components of the core network, or alternatively, may be external to the core network (e.g., in a new RAN 220).

[0061] Figure 2B Another example wireless network architecture 250 is described. For example, NGC 260 (also referred to as "5GC") can be functionally considered as a core network consisting of control plane functions (AMF) 264, user plane functions (UPF) 262, session management functions (SMF) 266, SLP 268, and LMF 270, which operate collaboratively to form the core network (i.e., NGC 260). User plane interface 263 and control plane interface 265 connect ng-eNB 224 to NGC 260, specifically to UPF 262 and AMF 264, respectively. In an additional configuration, gNB 222 can also connect to NGC 260 via control plane interface 265 to AMF 264 and user plane interface 263 to UPF 262. Furthermore, eNB 224 can communicate directly with gNB 222 via backhaul connection 223, regardless of whether it has direct gNB connectivity to NGC 260. In some configurations, the new RAN 220 may have only one or more gNB 222s, while other configurations include both one or more ng-eNB 224s and one or more gNB 222s. The gNB 222 or eNB 224 can be used with UE 204 (e.g., Figure 1 The base station of the new RAN 220 communicates with the AMF 264 on the N2 interface and with the UPF 262 on the N3 interface.

[0062] The AMF's functions include registration management, connection management, reachability management, mobility management, lawful interception, session management (SM) messaging between UE 204 and SMF 266, transparent proxy service for routing SM messages, access authentication and access authorization, short message service (SMS) messaging between UE 204 and the Short Message Service Function (SMSF) (not shown), and security anchor functionality (SEAF). The AMF also interacts with the Authentication Server Function (AUSF) (not shown) and UE 204, and receives the intermediate key established as a result of the UE 204 authentication process. In cases where authentication is based on the UMTS (Universal Mobile Telecommunications System) Subscriber Identity Module (USIM), the AMF retrieves security material from the AUSSF. The AMF's functions also include security context management (SCM). The SCM receives a key from the SEAF, which is used by the SCM to derive a key that varies depending on the access network. The functionality of the AMF also includes location service management for regulatory services, location service messaging between UE 204 and Location Management Function (LMF) 270 (which may correspond to location server 172) and between the new RAN 220 and LMF 270, EPS bearer identifier allocation for interoperability with Evolved Packet System (EPS), and UE 204 mobility event notification. Furthermore, the AMF also supports functionality for non-3GPP access networks.

[0063] The functions of the UPF include: acting as an anchor point for intra / inter-RAT mobility (where applicable), acting as an external protocol data unit (PDU) session point for interconnection to a data network (not shown), providing packet routing and forwarding, packet inspection, user plane policy rule enforcement (e.g., gating, redirection, traffic steering), lawful interception (user plane collection), traffic usage reporting, user plane quality of service (QoS) handling (e.g., UL / DL rate enforcement, reflective QoS marking in DL), UL traffic verification (mapping of service data flow (SDF) to QoS flow), transport-level packet marking in UL and DL, DL packet buffering and DL data notification triggering, and sending and forwarding one or more "end markers" to the source RAN node.

[0064] The functions of SMF 266 include session management, UE Internet Protocol (IP) address allocation and management, selection and control of user plane functions, configuration of traffic steering at the UPF for routing traffic to the correct destination, control of policy enforcement and QoS, and downlink data notification. The interface used by SMF 266 to communicate with AMF 264 is called the N11 interface.

[0065] Another optional aspect may include an LMF 270, which can communicate with the NGC 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 extending across multiple physical servers, etc.), or alternatively, each may correspond to a single server. The LMF 270 may be configured to support one or more location services for the UE 204, which can connect to the LMF 270 via the core network, the NGC 260, and / or via the Internet (not described).

[0066] Figure 3 A block diagram of a design 300 for base station 102 and UE 104 is shown, which can be Figure 1 One of the base stations and one of the UEs. Base station 102 may be equipped with T antennas 334a to 334t, while UE 104 may be equipped with R antennas 352a to 352r, where generally T≥1 and R≥1.

[0067] At base station 102, transmit processor 320 can receive data destined for one or more UEs from data source 312, select one or more modulation and coding schemes (MCS) for each UE based at least in part on channel quality indicators (CQI) received from each UE, process (e.g., encode and modulate) the data destined for each UE based at least in part on the MCS selected for each UE, and provide data symbols for all UEs. Transmit processor 320 can also process system information (e.g., semi-static resource allocation information (SRPI) and control information (e.g., CQI requests, grants, upper-layer signaling, etc.) and provide overhead symbols and control symbols. Transmit processor 320 can also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS)) and synchronization signals (e.g., primary synchronization signal (PSS) and secondary synchronization signal (SSS)). The transmit (TX) multiple-input multiple-output (MIMO) processor 330 can perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, overhead symbols, and / or reference symbols, where applicable, and can provide T output symbol streams to T modulators (MODs) 332a to 332t. Each modulator 332 can process its own output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 332 can further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The T downlink signals from modulators 332a to 332t can be transmitted via T antennas 334a to 334t, respectively. According to the aspects described in more detail below, position coding can be used to generate synchronization signals to convey additional information.

[0068] At UE 104, antennas 352a to 352r can receive downlink signals from base station 102 and / or other base stations and can provide the received signals to demodulators (DEMODs) 354a to 354r respectively. Each demodulator 354 can condition (e.g., filter, amplify, downconvert, and digitize) the received signal to obtain an input sample. Each demodulator 354 can further process the input sample (e.g., for OFDM, etc.) to obtain received symbols. MIMO detector 356 can obtain the received symbols from all R demodulators 354a to 354r, perform MIMO detection on these received symbols where applicable, and provide detected symbols. Receiver processor 358 can process (e.g., demodulate and decode) these detected symbols, provide the decoded data for UE 104 to data sink 360, and provide the decoded control information and system information to controller / processor 380. The channel processor can determine the Reference Received Power (RSRP), Received Signal Strength Indicator (RSSI), Reference Received Quality (RSRQ), Channel Quality Indicator (CQI), and so on. In some respects, one or more components of UE 104 may be included in the housing.

[0069] On the uplink, at UE 104, transmit processor 364 can receive and process data from data source 362 and control information from controller / processor 380 (e.g., reports including RSRP, RSSI, RSRQ, CQI, etc.). Transmit processor 364 can also generate reference symbols for one or more reference signals. Symbols from transmit processor 364 can be pre-encoded by TX MIMO processor 366 where applicable, further processed by modulators 354a to 354r (e.g., for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to base station 102. At base station 102, uplink signals from UE 104 and other UEs can be received by antenna 334, processed by demodulator 332, detected by MIMO detector 336 where applicable, and further processed by receive processor 338 to obtain decoded data and control information transmitted by UE 104. The receiver processor 338 can provide decoded data to the data trap 339 and decoded control information to the controller / processor 340. The base station 102 may include a communication unit 344 and communicates with the network controller 389 via the communication unit 344. The network controller 389 may include a communication unit 394, a controller / processor 390, and a memory 392.

[0070] The controller / processor 340 of base station 102, the controller / processor 380 of UE 104, the controller 390 of network controller 389 (which may be location server 172) and / or Figure 3Any other component may perform one or more techniques associated with broadcasting positioning assistance data differentially, as described in more detail elsewhere herein. For example, the controller / processor 340 of base station 102, the controller 390 of network controller 389, the controller / processor 380 of UE 104, and / or Figure 3 Any other component may execute or direct, for example Figure 9 The operation of process 900 and / or other processes as described herein. Memory 342, 382, ​​and 392 may store data and program code for base station 102, UE 104, and network controller 389, respectively. In some aspects, memory 342 and / or memory 382 and / or memory 392 may include a non-transient computer-readable medium storing one or more instructions for wireless communication. For example, these one or more instructions may be executed or direct, when executed by one or more processors of base station 102, network controller 389, and / or UE 104, for example... Figure 9 The operation of process 9 and / or other processes as described herein. Scheduler 346 can schedule the UE for data transmission on the downlink and / or uplink.

[0071] As indicated above, Figure 3 This is provided as an example. Other examples may differ from the one provided. Figure 3 The example described.

[0072] As discussed above, UE localization can be based on the PRS received by the UE. For example, timing differences between different UEs can be used for localization, such as Reference Signal Timing Difference (RSTD) measurements. However, in order to perform RSTD measurements, the UE needs information about when the PRS signal to be measured is expected to arrive. For example, a location server in the network (such as location server 172, 230a, or 230b) can send TDOA auxiliary data to the UE, which includes, for example, the expected RSTD value that the UE expects to measure between neighboring cells and a reference cell, as well as the uncertainty in that expected RSTD value. In some implementations, the expected RSTD value and uncertainty can be included in TDOA neighbor cell auxiliary information provided by the location server, for example, in the TDOA neighbor cell information element (IE). The location server can determine the expected RSTD value and uncertainty based on, for example, the UE's coarse prior location (e.g., localization from a cell ID or enhanced cell ID) and the known location of the corresponding neighboring eNB or gNB. Other information can also be specified in this TDOA neighbor cell IE, such as the cyclic prefix (CP) length of the neighbor cell's PRS and other configuration information about the neighbor cell's PRS (if it is different from the reference cell).

[0073] Figure 4 The structure of an exemplary system 400 for determining the size of a Reference Signal Time Difference (RSTD) search window, according to various aspects of this disclosure, is shown. As discussed above, a location server may provide the UE with an expected RSTD value and uncertainties in that expected RSTD value. Such expected RSTD value and uncertainties may be based on the distance between a reference cell and neighboring cells, as well as the size of the reference cell. (Refer to...) Figure 4 Neighboring cell 410 can transmit PRS to the UE associated with reference cell 420. Note that the neighboring cell can be an eNB, gNB, TRP, or any other suitable device capable of radio transmission and reception. Neighboring cell 410 and reference cell 420 can be separated by a known distance d. A UE (such as UE 104) may not have a known location within reference cell 420 and therefore may be at most a distance r from the reference cell, where r is the maximum cell radius. Thus, for example, UE 104 may not be closer to neighboring cell 410 than a first location 422 and not farther from neighboring cell 410 than a second location 424, where each of the first location 422 and the second location 424 is a distance r from reference cell 420. The neighboring cell can transmit PRS to UE 104 at time t and receive it by UE 104 at a time depending on the UE's location. For example, if UE 104 is in the first location 422, the PRS can be received via the shortest path 430, and if UE 104 is in the second location 424, the PRS can be received via the longest path 440. The earliest time that the PRS from neighboring cell 410 can be received by UE 104 (via the shortest path 430) is (t+d / c–r / c), where c is the propagation speed of the PRS. Similarly, the latest time that the PRS from neighboring cell 410 can be received by UE 104 (via the longest path 440) is (t+d / c+r / c). The RSTD of neighboring cell 410 is therefore measured by UE 104 in the first and second locations 422 and 424 as (d / c-2r / c) and (d / c), respectively. Therefore, the search window can be within the range [-r / c,+r / c] centered at (d / c–r / c). The center of the search window is the expected RSTD value provided by the location server, and the size of the search window corresponds to the uncertainty of the expected RSTD. Note that the center of this search window, and therefore the expected RSTD value, can vary depending on the transmission time difference of the reference signals provided by the reference cell and the neighboring cell. This transmission time difference may be referred to as the reference time difference or RTD. The above calculation assumes that the RTD is zero, which means that the transmissions from the reference cell 420 and the neighboring cell 410 are synchronized.

[0074] Figure 5 The typical set of PRS timing assumptions is shown. As discussed above, the UE can, for example, receive the expected RSTD value and the associated RSTD uncertainty in the auxiliary data received from the location server. Therefore, referring to... Figure 5 The RSTD search window can be centered on the expected RSTD 510, extending the RSTD uncertainty 520 before and after this expected RSTD 510. For example, the expected RSTD could be 10µs, and the associated RSTD uncertainty could be 100µs. In conventional PRS reception techniques, timing is tied to the serving cell's CRS / TRS / CSI channel. In other words, the Fast Fourier Transform (FFT) window used for receiving PRS is aligned with the symbol timing on the serving cell's CRS / TRS / CSI channel. For conventional techniques, this timing is tied to the serving cell's symbol timing because other channel activities and data decoding are performed in parallel with PRS reception and processing. Therefore, referring to... Figure 5 The search window for receiving the PRS can include four hypotheses: symbols 530, 540, 550, and 560, which include the corresponding cyclic prefixes 531, 541, 551, and 551, and the corresponding payloads 532, 542, 552, and 562. The UE can attempt to receive the PRS using each of these four symbols and select the symbol that allows for the best reception of the PRS, such as selecting the symbol with the highest signal-to-noise ratio (SNR) among these hypotheses.

[0075] In regular PRS reception, such as in Figure 5 As described, because the PRS assumption is tied to the serving cell's symbol timing, the chosen FFT window will very likely not cover the PRS received from neighboring cells. That is, the received PRS is highly unlikely to be aligned with the serving cell's symbol timing. This can impair PRS reception, such as... Figure 6 As shown. Figure 6 Visually explain the relationship between signal-to-noise ratio (SNR) and PRS symbol timing relative to the serving cell boundary 600. More specifically, Figure 6 The diagram illustrates how the SNR of the received PRS 630 can vary depending on its alignment with the symbol timing of the serving cell. For example, serving cell symbols 610 and 620 can be two hypothetical serving cell symbols used for receiving the PRS—in other words, the serving cell and symbols 610 and 620 can be... Figure 5The symbols 530-560 are included. Symbols 610, 620, and PRS 630 may include corresponding cyclic prefixes 611, 621, and 631, and corresponding payloads 612, 622, and 632. SNR plot 640 shows how the SNR of the received PRS 630 changes from being fully aligned with symbol 610 to being fully aligned with symbol 620 as the reception time of PRS 630 changes in steps of 8 ns. More specifically, plot 641 shows the SNR of the received PRS 630 using an FFT window fully aligned with PRS 630, plot 642 shows the SNR of the received PRS 630 using an FFT window aligned with symbol 610, and plot 643 shows the SNR of the received PRS 630 using an FFT window aligned with symbol 620. SNR plot 640 illustrates the SNR degradation caused by conventional PRS reception techniques (where PRS 630 uses an FFT window aligned with the symbols of the serving cell for reception). Unless PRS 630 is perfectly aligned with symbol 610 or symbol 620, an SNR loss will occur, and this SNR loss is additional to any SNR loss from channel interference or other sources. Therefore, it would be desirable for the UE to receive PRS without suffering SNR loss from conventional techniques.

[0076] The example implementation allows the UE to determine the RSTD values ​​of neighboring cells without binding PRS reception to the serving cell symbol timing. More specifically, the example implementation provides a measurement gap for receiving PRS, during which the UE does not perform other modem activities. The FFT window timing is not bound to the serving cell symbol timing, and the PRS timing assumptions are based solely on the expected RSTD values ​​and associated RSTD uncertainties. Therefore, according to various aspects of this disclosure, the UE can determine the FFT window offset for obtaining the peak SNR of the PRS received from neighboring cells. Furthermore, in some implementations, the example UE may incorporate a more compact RSTD search window compared to conventional techniques, and may further reduce the number and timing of subsequent PRS assumptions to focus on the determined FFT window offset.

[0077] Figure 7 A depiction 700 of the RSTD determination and PRS timing assumptions according to various aspects of this disclosure is shown. Similar to... Figure 5The expected RSTD value and the associated RSTD uncertainty are known, for example, provided to UE 104 by the location server in the auxiliary information, as discussed above. However, unlike conventional techniques, PRS assumes that timing is not tied to the serving cell timing. The FFT window offset search space 710 therefore depends only on the expected RSTD value and the RSTD uncertainty. More specifically, the FFT window offset search space 710 for receiving PRS extends from the difference between the expected RSTD value and the RSTD uncertainty (expected RSTD – RSTD uncertainty) to the sum of the expected RSTD value and the RSTD uncertainty (expected RSTD + RSTD uncertainty). UE 104 can determine the FFT window offset that maximizes the SNR of received PRS within the search space 710.

[0078] In some implementations, UE 104 may initially select a PRS hypothesis that maximizes the SNR of the received PRS, while additionally determining an FFT window offset that maximizes the SNR of the received PRS. In some implementations, this selection and determination may be performed concurrently by UE 104. For example, during the Nth PRS reception 720, UE 104 may select from a first PRS symbol hypothesis 721, a second PRS symbol hypothesis 722, and a third PRS symbol hypothesis 723 to select a PRS symbol hypothesis that maximizes the SNR of the received PRS. UE 104 may concurrently determine an FFT window offset that maximizes the SNR of the received PRS. Subsequently, for example, during the (N+1)th PRS reception 730, UE 104 may cause PRS symbol hypothesis 731 to be centered on an FFT window offset that maximizes the SNR of the received PRS during the Nth PRS reception.

[0079] More generally, UE 104 can reduce the number of PRS assumptions in subsequent PRS receptions and base these PRS assumptions on the determined FFT window offset. Furthermore, in some implementations, UE 104 can also reduce RSTD uncertainty associated with subsequent PRS receptions. Additionally, although the FFT window offset and RSTD are determined without reference to the serving cell timing, the FFT window offset and RSTD can subsequently be adjusted with reference to this serving cell timing.

[0080] Figure 8 The illustration shows a UE 800 implemented to support the use of PRS signals to locate the UE as described herein (e.g., it could be...). Figure 1 A schematic block diagram illustrating some exemplary features of UE 104 is shown below. UE 800 is executable. Figure 9The process flow is shown in the diagram. UE 800 may include, for example, one or more processors 802, memory 804, and external interfaces (such as transceiver 810, e.g., a wireless network interface) operably coupled to non-transient computer-readable medium 820 and memory 804 via one or more connections 806 (e.g., bus, line, fiber optic, link, etc.). UE 800 may further include additional items not shown, such as a user interface by which a user can interface with the UE, which may include, for example, a display, keypad, or other input device (such as a virtual keypad on a display), or a satellite positioning system receiver. In some example implementations, all or part of UE 800 may take the form of a chipset, etc. Transceiver 810 may include, for example, a transmitter 812 implemented to transmit one or more signals over one or more types of wireless communication networks, and a receiver 814 to receive one or more signals transmitted over such one or more types of wireless communication networks.

[0081] In some embodiments, UE 800 may include an antenna 811, which may be internal or external. The UE antenna 811 may be used to transmit and / or receive signals processed by transceiver 810. In some embodiments, the UE antenna 811 may be coupled to transceiver 810. In some embodiments, measurements of signals received (transmitted) by UE 800 may be performed at the connection point between UE antenna 811 and transceiver 810. For example, a measurement reference point for measuring the received (transmitted) RF signal may be an input (output) terminal of receiver 814 (transmitter 812) and an output (input) terminal of UE antenna 811. In a UE 800 having multiple UE antennas 811 or an antenna array, the antenna connector may be considered as a virtual point representing the aggregated output (input) of multiple UE antennas. In some embodiments, UE 800 may measure received signals (including signal strength and TOA measurements), and the raw measurements may be processed by one or more processors 802.

[0082] The one or more processors 802 may be implemented using a combination of hardware, firmware, and software. For example, the one or more processors 802 may be configured to perform the functions discussed herein by implementing one or more instructions or program code 808 on a non-transient computer-readable medium, such as medium 820 and / or memory 804. In some embodiments, the one or more processors 802 may represent one or more circuits that may be configured to perform at least a portion of a data signal calculation procedure or process associated with the operation of UE 800.

[0083] Medium 820 and / or memory 804 may store instruction or program code 808 containing executable code or software instructions that, when executed by one or more processors 802, cause those processors 802 to operate as a dedicated computer programmed to perform the techniques disclosed herein. As explained in UE 800, medium 820 and / or memory 804 may include one or more components or modules that may be implemented by the one or more processors 802 to perform the methodologies described herein. Although each component or module is described as software in medium 820 executable by the one or more processors 802, it should be understood that each component or module may be stored in memory 804 or may be dedicated hardware in or outside of the one or more processors 802. Several software modules and data tables may reside in medium 820 and / or memory 804 and be utilized by one or more processors 802 to manage both the communications and functionalities described herein. It should be understood that the organization of the contents of the medium 820 and / or memory 804 as shown in UE 800 is merely exemplary, and thus, the functionality of the modules and / or data structures may be combined, separated, and / or constructed in different ways depending on the implementation of UE 800.

[0084] The medium 820 and / or memory 804 may include a positioning session module 822, which, when implemented by one or more processors 802, configures the one or more processors 802 to participate in a positioning session for the UE. For example, the one or more processors 802 may be configured to participate in the positioning session by providing positioning capabilities to a location server via transceiver 810. The one or more processors 802 may be configured to receive positioning assistance data from a location server and / or serving base station via transceiver 810. The one or more processors 802 may be configured to perform positioning measurements, for example, using transceiver 810. The one or more processors 802 may be further configured to provide measurement information reports to network nodes (such as location servers, serving base stations, or sidelink UEs) via transceiver 810.

[0085] The methodologies described herein can be implemented through various means depending on the application. For example, these methodologies can be implemented in hardware, firmware, software, or any combination thereof. For hardware implementation, the one or more processors 802 can be implemented within one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, electronic devices, other electronic units designed to perform the functions described herein, or combinations thereof.

[0086] For firmware and / or software implementations, these methodologies can be implemented using modules (e.g., procedures, functions, etc.) that perform the functions described herein. Any machine-readable medium that tangibly embodies instructions can be used to implement the methodologies described herein. For example, software code can be stored in a non-transient computer-readable medium 820 or memory 804 connected to and executed by one or more processors 802. Memory can be implemented within or outside of the one or more processors. As used herein, the term "memory" means any type of long-term, short-term, volatile, non-volatile, or other memory, and is not limited to any particular type or number of memories, or the type of medium on which memory is stored.

[0087] If implemented in firmware and / or software, the functionality may be stored as one or more instructions or program code 808 on a non-transient computer-readable medium (such as medium 820 and / or memory 804). Examples include computer-readable media encoding data structures and computer-readable media encoding computer programs 808. For example, a non-transient computer-readable medium including program code 808 stored thereon may include program code 808 for supporting the positioning of the UE using PRS signals according to the disclosed embodiments. The non-transient computer-readable medium 820 includes a physical computer storage medium. The storage medium may be any available medium that can be accessed by a computer. By way of example and not limitation, such non-transient computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage, or other magnetic storage devices, or any other medium that can be used to store desired program code 808 in the form of instructions or data structures and that can be accessed by a computer; as used herein, disk and disc include compact discs (CDs), laser discs, optical discs, digital multi-purpose discs (DVDs), floppy disks, and Blu-ray discs, wherein disks often magnetically reproduce data, while discs optically reproduce data using lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0088] In addition to being stored on the computer-readable medium 820, instructions and / or data may also be provided as signals included on a transmission medium in a communication apparatus. For example, a communication apparatus may include a transceiver 810 having signals indicating instructions and data. These instructions and data are configured to cause one or more processors to perform the functions outlined in the claims. That is, the communication apparatus includes a transmission medium having signals indicating information for performing the disclosed functions.

[0089] Memory 804 can represent any data storage device. Memory 804 may include, for example, main memory and / or secondary memory. Main memory may include, for example, random access memory, read-only memory, etc. Although described in this example as separate from one or more processors 802, it should be understood that all or part of the main memory may be located within one or more processors 802 or otherwise coexist / coupled with one or more processors 802. Secondary memory may include, for example, memory of the same or similar type as the main memory and / or one or more data storage devices or systems (such as, for example, disk drives, optical disc drives, tape drives, solid-state drives, etc.).

[0090] In some implementations, secondary memory may be operatively accommodated or otherwise configured to be coupled to non-transient computer-readable medium 820. Thus, in some example implementations, the methods and / or apparatus presented herein may take the form of a computer-readable medium 820 which may include all or a portion of computer-readable code 808 stored thereon, which, when executed by one or more processors 802, may be operatively implemented to perform all or a portion of the example operations as described herein. Computer-readable medium 820 may be part of memory 804.

[0091] Figure 9 A flowchart of an exemplary method 900 for supporting the location of a UE (such as UE 104) performed by a UE in a wireless network is shown in a manner consistent with the disclosed implementation.

[0092] In block 902, the UE determines a first reference signal time difference (RSTD) estimate and a first RSTD uncertainty associated with the first RSTD estimate. For example, the UE may determine the first RSTD estimate and the first RSTD uncertainty based on auxiliary data received, such as in a neighboring cell IE (Transient Information Area) of the TDOA (Transient Information Area) or in another IE received from a location server or other devices in the network associated with the UE. In some aspects, the means for determining the first RSTD estimate and the first RSTD uncertainty may include… Figure 8 The UE 800 shown includes a wireless transceiver 810 with dedicated hardware or executable code or software instructions (such as a location session module 822) in memory 804 and / or medium 820, and one or more processors 802.

[0093] In block 904, the UE identifies a search interval for the first RSTD value, wherein the search interval extends from the difference between the first RSTD estimate and the first RSTD uncertainty to the sum of the first RSTD estimate and the first RSTD uncertainty. In some aspects, the UE's modem performs receive and transmit operations for receiving the first PRS and does not perform other receive or transmit operations during the search interval. Means for identifying the search interval for the first RSTD value may include... Figure 8 The UE 800 shown includes a wireless transceiver 810 with dedicated hardware or executable code or software instructions (such as a location session module 822) in memory 804 and / or medium 820, and one or more processors 802.

[0094] In box 906, the UE receives radio signals during the identified search interval. The means for receiving radio signals during the identified search interval may include... Figure 8 The UE 800 shown includes a wireless transceiver 810 with dedicated hardware or executable code or software instructions (such as a location session module 822) in memory 804 and / or medium 820, and one or more processors 802.

[0095] In block 908, the UE determines a Fast Fourier Transform (FFT) window offset for decoding a first Positioning Reference Signal (PRS) received during the identified search interval. In some aspects, this FFT window offset is not based on a Cellular Reference Signal (CRW) or Tracking Reference Signal (TRS) of the serving cell associated with the UE. In some aspects, the UE may further adjust the determined FFT window offset relative to the timing of the anchor serving cell associated with the UE. In some aspects, the determined FFT window offset is an offset that aligns the FFT window with the first PRS. In some aspects, the FFT window offset is not an integer number of offset symbols relative to the timing of the anchor serving cell associated with the UE. The means for determining the FFT window offset for decoding the first PRS may include... Figure 8 The UE 800 shown includes a wireless transceiver 810 with dedicated hardware or executable code or software instructions (such as a location session module 822) in memory 804 and / or medium 820, and one or more processors 802.

[0096] In block 910, the UE determines the first RSTD value at least in part based on the determined FFT window offset. In some aspects, the first RSTD value is associated with a first transmit / receive point (TRP) associated with the first PRS. In other aspects, the first RSTD value may be associated with a neighboring cell or another radio device associated with the first PRS. In some aspects, the UE may determine the first RSTD value concurrently with determining the FFT window offset in block 908. The means for determining the first RSTD value may include... Figure 8 The UE 800 shown includes a wireless transceiver 810 with dedicated hardware or executable code or software instructions (such as a location session module 822) in memory 804 and / or medium 820, and one or more processors 802.

[0097] In some aspects, operation 900 may further include determining an FFT window offset for decoding a subsequently received second PRS based at least in part on a first RSTD value. In some aspects, operation 900 may further include determining a second RSTD uncertainty associated with the second RSTD value, wherein the second RSTD uncertainty is less than the first RSTD uncertainty. In some aspects, the second RSTD estimate is equal to the first RSTD value.

[0098] Throughout this specification, the terms "an example," "an example," "some examples," or "exemplary implementation" mean that a particular feature, structure, or characteristic described in conjunction with a feature and / or example may be included in at least one feature and / or example of the claimed subject matter. Therefore, phrases appearing throughout the specification such as "an example," "an example," "some examples," or "in some implementations," or other similar phrases, do not necessarily all refer to the same feature, example, and / or limitation. Furthermore, these particular features, structures, or characteristics may be combined in one or more examples and / or features.

[0099] Some portions of the detailed description included herein are presented in the form of algorithms or symbolic representations of operations on binary digital signals stored in the memory of a particular device or dedicated computing device or platform. In the context of this particular specification, the terms "particular device," etc., include general-purpose computers that, once programmed, perform specific operations according to instructions from program software. Algorithm descriptions or symbolic representations are examples of techniques used by those skilled in the art of signal processing or related fields to convey the essence of their work to others skilled in the art. An algorithm herein and generally is considered as a self-consistent sequence of operations or similar signal processing leading to a desired result. In this context, the operation or processing involves the physical manipulation of physical quantities. Typically, but not necessarily, such quantities may take the form of electrical or magnetic signals capable of being stored, transmitted, combined, compared, or otherwise manipulated. It has proven convenient at times to refer to such signals as bits, data, values, elements, symbols, characters, items, numbers, numerical values, etc., primarily for reasons of general use. However, it should be understood that all such terms, or similar terms, are to be associated with the appropriate physical quantity and are merely convenient labels. Unless otherwise specifically stated, as will be apparent from the discussion herein, throughout this specification, the use of terms such as “processing,” “calculating,” “determining,” and “determining” refers to the actions or processes of a particular device (such as a dedicated computer, dedicated computing device, or similar dedicated electronic computing device). In the context of this specification, therefore, a dedicated computer or similar dedicated electronic computing device is capable of manipulating or transforming signals that are generally represented as physical electronic or magnetic quantities within the memory, registers, or other information storage, transmission, or display devices of such dedicated computer or similar dedicated electronic computing device.

[0100] In the detailed description above, numerous specific details have been set forth to provide a thorough understanding of the claimed subject matter. However, those skilled in the art will understand that the claimed subject matter can be practiced without these specific details. In other instances, methods and apparatus known to those of ordinary skill in the art have not been described in detail to avoid obscuring the claimed subject matter.

[0101] As used herein, the terms “and,” “or,” and “and / or” may include a variety of meanings, which are also contemplated, at least in part, depending on the context in which such terms are used. Generally, “or,” when used to relate a list such as A, B, or C, is intended to mean A, B, and C (in the inclusive sense) and A, B, or C (in the exclusive sense). Additionally, the term “one or more” as used herein may be used to describe any feature, structure, or characteristic in the singular form, or to describe multiple features, structures, or characteristics, or some other combination thereof. However, it should be noted that this is merely an illustrative example, and the claimed subject matter is not limited to this example.

[0102] Examples of implementations are described in the following numbered clauses:

[0103] 1. A method for determining a first reference signal time difference (RSTD) value, the method being performed by a user equipment (UE) associated with a wireless network and comprising:

[0104] Determine the first RSTD estimate and the first RSTD uncertainty associated with the first RSTD value;

[0105] Identify the search interval for the first RSTD value, the search interval extending from the difference between the first RSTD estimate and the first RSTD uncertainty to the sum of the first RSTD estimate and the first RSTD uncertainty;

[0106] Receive wireless signals during the identified search area;

[0107] Determine the Fast Fourier Transform (FFT) window offset for decoding the first Positioning Reference Signal (PRS) received during the identified search interval; and

[0108] The first RSTD value is determined at least in part based on the determined FFT window offset.

[0109] 2. The method as described in Clause 1, wherein the first RSTD value is associated with a first transmit receiving point (TRP) associated with the first PRS.

[0110] 3. The method of any of the provisions 1-2 further includes determining the FFT window offset for decoding the subsequently received second PRS based at least in part on the first RSTD value.

[0111] 4. The method of Clause 3 further includes determining a second RSTD uncertainty associated with the second RSTD value, the second RSTD uncertainty being less than the first RSTD uncertainty.

[0112] 5. The method as described in any of Clauses 3-4, wherein the second RSTD estimate is equal to the first RSTD value.

[0113] 6. The method of any of Items 1-5, wherein the FFT window offset is determined concurrently with the determination of the first RSTD value.

[0114] 7. The method as described in Clause 1, further comprising adjusting the determined FFT window offset relative to the timing of the anchor serving cell associated with the UE.

[0115] 8. The method as described in any of Clauses 1-7, wherein the FFT window offset is not based on the Cell Reference Signal (CRS) or Tracking Reference Signal (TRS) of the serving cell associated with the UE.

[0116] 9. The method of any of the provisions 1-8, wherein determining the FFT window offset aligns the FFT window with the first PRS.

[0117] 10. The method of any of the provisions 1-9, wherein during the search interval, the modem of the UE performs a receive and transmit operation for receiving the first PRS and does not perform any other receive or transmit operation.

[0118] 11. The method of any of the provisions 1-10, wherein the FFT window offset used for decoding the first PRS is not an integer number of offset symbols relative to the timing of the anchor serving cell associated with the UE.

[0119] 12. A user equipment (UE) configured to determine a first reference signal time difference (RSTD) value, the UE being associated with a wireless network and comprising:

[0120] A wireless transceiver configured to communicate wirelessly with entities in the wireless network;

[0121] At least one memory; and

[0122] At least one processor coupled to the wireless transceiver and the at least one memory, wherein the at least one processor is configured to:

[0123] Determine the first RSTD estimate and the first RSTD uncertainty associated with the first RSTD value;

[0124] Identify the search interval for the first RSTD value, the search interval extending from the difference between the first RSTD estimate and the first RSTD uncertainty to the sum of the first RSTD estimate and the first RSTD uncertainty;

[0125] Receive wireless signals via the wireless transceiver during the identified search range;

[0126] Determine the Fast Fourier Transform (FFT) window offset for decoding the first Positioning Reference Signal (PRS) received during the identified search interval; and

[0127] The first RSTD value is determined at least in part based on the determined FFT window offset.

[0128] 13. The UE as described in Clause 12, wherein the first RSTD value is associated with a first transmit receiving point (TRP) associated with the first PRS.

[0129] 14. The UE as described in any of Clauses 12-13, wherein the at least one processor is further configured to determine the FFT window offset for decoding the subsequently received second PRS based at least in part on the first RSTD value.

[0130] 15. The UE as described in Clause 14, wherein the at least one processor is further configured to determine a second RSTD uncertainty associated with the second RSTD value, the second RSTD uncertainty being less than the first RSTD uncertainty.

[0131] 16. The UE as described in any of Clauses 14-15, wherein the second RSTD estimate is equal to the first RSTD value.

[0132] 17. The UE as described in any of Clauses 12-16, wherein the FFT window offset is determined concurrently with the determination of the first RSTD value.

[0133] 18. The UE as described in any of Clauses 12-17, wherein the at least one processor is further configured to offset the FFT window relative to a timing adjustment of the anchor serving cell associated with the UE.

[0134] 19. A UE as described in any of Clauses 12-18, wherein the FFT window offset is not based on the Cell Reference Signal (CRS) or Tracking Reference Signal (TRS) of the serving cell associated with the UE.

[0135] 20. The UE as described in any of Clauses 12-19, wherein the FFT window offset used for decoding the first PRS is not an integer number of offset symbols relative to the timing of the anchor serving cell associated with the UE.

[0136] 21. The UE as described in any of Clauses 12-20, wherein during the search interval, the radio transceiver performs receive and transmit operations for receiving the first PRS and does not perform other receive or transmit operations.

[0137] 22. A non-transitory computer-readable storage medium storing instructions that, when executed by one or more processors of a user equipment (UE) associated with a wireless network, cause the UE to perform operations, the operations including:

[0138] Determine the first RSTD estimate and the first RSTD uncertainty associated with the first RSTD value;

[0139] Identify the search interval for the first RSTD value, the search interval extending from the difference between the first RSTD estimate and the first RSTD uncertainty to the sum of the first RSTD estimate and the first RSTD uncertainty;

[0140] Receive wireless signals during the identified search area;

[0141] Determine the Fast Fourier Transform (FFT) window offset for decoding the first Positioning Reference Signal (PRS) received during the identified search interval; and

[0142] The first RSTD value is determined at least in part based on the determined FFT window offset.

[0143] 23. The non-transient computer-readable storage medium as described in Clause 22, wherein the first RSTD value is associated with a first transmit receiving point (TRP) associated with the first PRS.

[0144] 24. A non-transient computer-readable storage medium as described in any of Clauses 22-23, wherein execution of the instructions causes the UE to perform an operation that further includes: determining an FFT window offset for decoding a subsequently received second PRS based at least in part on the first RSTD value.

[0145] 25. The non-transient computer-readable storage medium as described in Clause 24, wherein execution of the instructions causes the UE to perform an operation that further includes determining a second RSTD uncertainty associated with the second RSTD value, the second RSTD uncertainty being less than the first RSTD uncertainty.

[0146] 26. A non-transient computer-readable storage medium as described in any of Clauses 24-25, wherein the second RSTD estimate is equal to the first RSTD value.

[0147] 27. A non-transient computer-readable storage medium as described in any of clauses 22-26, wherein the FFT window offset is determined concurrently with the determination of the first RSTD value.

[0148] 28. A non-transient computer-readable storage medium as described in any of clauses 22-27, wherein execution of the instructions causes the UE to perform an operation that further includes adjusting the first RSTD value based on the timing of the anchor serving cell associated with the UE.

[0149] 29. A non-transient computer-readable storage medium as described in any of Clauses 22-28, wherein the FFT window offset is not based on the Cellular Reference Signal (CRS) or Tracking Reference Signal (TRS) of the serving cell associated with the UE.

[0150] 30. A non-transient computer-readable storage medium as described in any of clauses 22-29, wherein the FFT window offset for decoding the first PRS is not an integer number of offset symbols relative to the timing of the anchor serving cell associated with the UE.

[0151] While the features currently considered exemplary have been explained and described, those skilled in the art will understand that various other modifications can be made and equivalents can be substituted without departing from the claimed subject matter. Additionally, numerous modifications can be made to adapt a particular scenario to the teachings of the claimed subject matter without departing from the central concepts described herein.

[0152] Therefore, the subject matter claimed is not intended to be limited to the specific examples disclosed, but may also include all aspects falling within the scope of the appended claims and their equivalents.

Claims

1. A method for determining a first reference signal time difference (RSTD) value, the method being performed by a user equipment (UE) associated with a wireless network and comprising: Determine the first RSTD estimate and the first RSTD uncertainty associated with the first RSTD value; Identify the search interval for the first RSTD value, the search interval extending from the difference between the first RSTD estimate and the first RSTD uncertainty to the sum of the first RSTD estimate and the first RSTD uncertainty; Receive wireless signals during the identified search area; Determine the Fast Fourier Transform (FFT) window offset for decoding the first Position Reference Signal (PRS) received during the identified search interval; as well as The first RSTD value is determined at least in part based on the determined FFT window offset.

2. The method of claim 1, wherein the first RSTD value is associated with a first transmit receiving point (TRP) associated with the first PRS.

3. The method of claim 1, further comprising determining an FFT window offset for decoding a subsequently received second PRS based at least in part on the first RSTD value.

4. The method of claim 3, further comprising determining a second RSTD uncertainty associated with a second RSTD value, the second RSTD uncertainty being less than the first RSTD uncertainty.

5. The method of claim 3, wherein the second RSTD estimate is equal to the first RSTD value.

6. The method of claim 1, wherein the FFT window offset is determined concurrently with determining the first RSTD value.

7. The method of claim 1, further comprising adjusting the determined FFT window offset relative to the timing of the anchor serving cell associated with the UE.

8. The method of claim 1, wherein the FFT window offset is not based on the Cell Reference Signal (CRS) or Tracking Reference Signal (TRS) of the serving cell associated with the UE.

9. The method of claim 1, wherein determining the FFT window offset aligns the FFT window with the first PRS.

10. The method of claim 1, wherein during the search interval, the modem of the UE performs receive and transmit operations for receiving the first PRS and does not perform other receive or transmit operations.

11. The method of claim 1, wherein the FFT window offset for decoding the first PRS is not an integer number of offset symbols relative to the timing of the anchor serving cell associated with the UE.

12. A user equipment (UE) configured to determine a first reference signal time difference (RSTD) value, the UE being associated with a wireless network and comprising: A wireless transceiver configured to communicate wirelessly with entities in the wireless network; At least one memory; as well as At least one processor coupled to the wireless transceiver and the at least one memory, wherein the at least one processor is configured to: Determine the first RSTD estimate and the first RSTD uncertainty associated with the first RSTD value; Identify the search interval for the first RSTD value, the search interval extending from the difference between the first RSTD estimate and the first RSTD uncertainty to the sum of the first RSTD estimate and the first RSTD uncertainty; The wireless transceiver is used to receive wireless signals during the identified search range. Determine the Fast Fourier Transform (FFT) window offset for decoding the first Position Reference Signal (PRS) received during the identified search interval; as well as The first RSTD value is determined at least in part based on the determined FFT window offset.

13. The UE of claim 12, wherein the first RSTD value is associated with a first transmit receiving point (TRP) associated with the first PRS.

14. The UE of claim 12, wherein the at least one processor is further configured to determine the FFT window offset for decoding the subsequently received second PRS based at least in part on the first RSTD value.

15. The UE of claim 14, wherein the at least one processor is further configured to determine a second RSTD uncertainty associated with a second RSTD value, the second RSTD uncertainty being less than the first RSTD uncertainty.

16. The UE of claim 14, wherein the second RSTD estimate is equal to the first RSTD value.

17. The UE of claim 12, wherein the FFT window offset is determined concurrently with determining the first RSTD value.

18. The UE of claim 12, wherein the at least one processor is further configured to offset the FFT window relative to a timing adjustment of the anchor serving cell associated with the UE.

19. The UE of claim 12, wherein the FFT window offset is not based on the Cell Reference Signal (CRS) or Tracking Reference Signal (TRS) of the serving cell associated with the UE.

20. The UE of claim 12, wherein the FFT window offset for decoding the first PRS is not an integer number of offset symbols relative to the timing of the anchor serving cell associated with the UE.

21. The UE of claim 12, wherein during the search interval, the wireless transceiver performs receive and transmit operations for receiving the first PRS and does not perform other receive or transmit operations.

22. A non-transitory computer-readable storage medium storing instructions that, when executed by one or more processors of a user equipment (UE) associated with a wireless network, cause the UE to perform operations, the operations including: Determine the first RSTD estimate and the first RSTD uncertainty associated with the first RSTD value; Identify the search interval for the first RSTD value, the search interval extending from the difference between the first RSTD estimate and the first RSTD uncertainty to the sum of the first RSTD estimate and the first RSTD uncertainty; Receive wireless signals during the identified search area; Determine the Fast Fourier Transform (FFT) window offset for decoding the first Position Reference Signal (PRS) received during the identified search interval; as well as The first RSTD value is determined at least in part based on the determined FFT window offset.

23. The non-transient computer-readable storage medium of claim 22, wherein the first RSTD value is associated with a first transmit-receive point (TRP) associated with the first PRS.

24. The non-transient computer-readable storage medium of claim 22, wherein execution of the instructions causes the UE to perform an operation that further includes: determining an FFT window offset for decoding a subsequently received second PRS based at least in part on the first RSTD value.

25. The non-transient computer-readable storage medium of claim 24, wherein execution of the instructions causes the UE to perform an operation further comprising: determining a second RSTD uncertainty associated with a second RSTD value, the second RSTD uncertainty being less than the first RSTD uncertainty.

26. The non-transient computer-readable storage medium of claim 24, wherein the second RSTD estimate is equal to the first RSTD value.

27. The non-transient computer-readable storage medium of claim 22, wherein the FFT window offset is determined concurrently with the determination of the first RSTD value.

28. The non-transient computer-readable storage medium of claim 22, wherein execution of the instructions causes the UE to perform an operation further comprising: adjusting the first RSTD value based on the timing of the anchor serving cell associated with the UE.

29. The non-transient computer-readable storage medium of claim 22, wherein the FFT window offset is not based on the Cell Reference Signal (CRS) or Tracking Reference Signal (TRS) of the serving cell associated with the UE.

30. The non-transient computer-readable storage medium of claim 22, wherein the FFT window offset for decoding the first PRS is not an integer number of offset symbols relative to the timing of the anchor serving cell associated with the UE.

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