Multi-path detection and mitigation using doppler in RF-based positioning

Abstract

Aspects presented herein may improve performance and accuracy of RF-based positioning. Aspects presented herein may enable a device to detect and mitigate multipath effects in RF-based positioning using RF Doppler measurements. The RF-based positioning may include satellite navigation, ground positioning systems, and / or indoor positioning. In one aspect, the UE receives signals from one or more entities via a receiver. The UE determines whether each received signal is a multipath signal based on Doppler shift measurements. The UE de-weights or excludes one or more of the received signals when estimating the location of the UE based on whether the respective received signals are determined as multipath signals.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. non-provisional patent application serial number 17 / 809,533, entitled “USING DOPPLER FOR MULTIPATH DETECTION AND MITIGATION IN RF-BASED POSITIONING” and filed on June 28, 2022, which is expressly incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates generally to positioning systems, and more particularly to positioning systems related to radio frequency (RF) based positioning. Background Art

[0004] Wireless communication systems are widely deployed to provide a variety of telecommunication services, such as telephony, video, data, messaging, and broadcast. Typical wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

[0005] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at city, national, regional, and even global levels. An example telecommunication standard is 5G New Radio (NR). 5G NR is part of the continuous mobile broadband evolution promulgated by the Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with the Internet of Things (IoT)) and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable low latency communications (URLLC). Certain aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. Further improvements to 5G NR technology are needed. In addition, these improvements may also be applicable to other multiple access technologies and telecommunication standards that employ these technologies. Summary of the invention

[0006] A simplified summary of one or more aspects is presented below to provide a basic understanding of these aspects. This summary is not an extensive review of all contemplated aspects. This summary is neither intended to identify key or important elements of all aspects, nor to describe the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to a more detailed description presented later.

[0007] In one aspect of the present disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus receives signals from one or more entities via a receiver. The apparatus determines whether each received signal is a multipath signal based on Doppler shift measurements. The apparatus de-weights or excludes one or more of the received signals when estimating the location of the UE based on whether the corresponding received signal is determined to be a multipath signal.

[0008] In one aspect of the present disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus receives signals from one or more entities via a receiver. The apparatus determines whether each received signal is a multipath signal based on Doppler shift measurements. The apparatus transmits measurement information associated with one or more of the received signals via a transmitter, the measurement information at least partially indicating whether each of the one or more signals is a multipath signal.

[0009] To achieve the aforementioned and related purposes, one or more aspects include the features fully described below and particularly pointed out in the claims. The following description and the accompanying drawings set forth in detail some exemplary features of one or more aspects. However, these features are only indicative of only some of the various ways in which the principles of the various aspects can be employed. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a diagram illustrating an example of a wireless communication system and an access network.

[0011] Figure 2A is a diagram illustrating an example of a first frame according to various aspects of the present disclosure.

[0012] Figure 2B is a diagram illustrating an example of DL channels within a subframe according to various aspects of the present disclosure.

[0013] Figure 2C is a diagram illustrating an example of a second frame according to various aspects of the present disclosure.

[0014] Figure 2D is a diagram illustrating an example of UL channels within a subframe according to various aspects of the present disclosure.

[0015] Figure 3is a diagram illustrating an example of a base station and a user equipment (UE) in an access network.

[0016] Figure 4 is a diagram illustrating an example of UE positioning based on reference signal measurement.

[0017] Figure 5 is a diagram illustrating an example of global navigation satellite system (GNSS) positioning according to various aspects of the present disclosure.

[0018] Figure 6 is a diagram illustrating an example of real-time kinematic (RTK) positioning according to various aspects of the present disclosure.

[0019] Figure 7 is a diagram illustrating an example of non-line-of-sight (NLOS) GNSS measurements in an urban area in accordance with various aspects of the present disclosure.

[0020] Figure 8 is a diagram illustrating an example in which a GNSS device according to various aspects of the present disclosure detects a multipath effect based on Doppler measurement in a GNSS scenario.

[0021] Fig. 9 is a diagram illustrating an example in which a UE detects a multipath effect based on Doppler measurement in a terrestrial scenario according to various aspects of the present disclosure.

[0022] Fig.10 A flow chart of a wireless communication method.

[0023] Fig.11 A flow chart of a wireless communication method.

[0024] Fig.12 are diagrams illustrating examples of hardware implementations of example devices and / or network entities.

[0025] Fig.13 A flow chart of a wireless communication method.

[0026] Fig.14 are diagrams illustrating examples of hardware implementations of example devices and / or network entities. DETAILED DESCRIPTION

[0027] The various aspects presented herein can improve the performance and accuracy of RF-based positioning. The various aspects presented herein can enable a device to use RF Doppler measurements to detect and mitigate multipath effects in RF-based positioning. RF-based positioning may include satellite navigation (e.g., GNSS, low earth orbit (LEO) satellites, etc.), ground positioning systems (e.g., network-based positioning associated with 5G NR, 4G LTE, etc.) and / or indoor positioning (e.g., Wi-Fi-based positioning, ultra-wideband (UWB) positioning, Bluetooth positioning, etc.). Since Doppler measurements may be ubiquitous in most RF-based systems, and additional hardware infrastructure may not be specified, the various aspects presented herein may be applicable to a wide range of RF-based positioning technologies.

[0028] The detailed description set forth below in conjunction with the accompanying drawings is a description of various configurations and does not represent the only configurations with which the concepts described herein can be practiced. In order to provide a thorough understanding of the various concepts, the specific embodiments include specific details. However, these concepts can be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form to avoid obscuring these concepts.

[0029] Several aspects of the telecommunication system are also presented with reference to various apparatus and methods. These apparatus and methods are described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements"). These elements can be implemented using electronic hardware, computer software, or any combination thereof. Whether these elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0030] As an example, an element or any part of an element or any combination of elements can be implemented as a "processing system", which includes one or more processors. The example of a processor includes a microprocessor, a microcontroller, a graphics processing unit (GPU), a central processing unit (CPU), an application processor, a digital signal processor (DSP), a reduced instruction set computing (RISC) processor, a system on a chip (SoC), a baseband processor, a field programmable gate array (FPGA), a programmable logic device (PLD), a state machine, a gate logic piece, a discrete hardware circuit and other suitable hardware configured to perform various functionalities described throughout the present disclosure. One or more processors in a processing system can execute software. Whether referred to as software, firmware, middleware, microcode, hardware description language or other terms, software should be broadly interpreted as meaning an instruction, an instruction set, a code, a code segment, a program code, a program, a subroutine, a software component, an application, a software application, a software package, a routine, a subroutine, an object, an executable, a thread of execution, a process, a function or any combination thereof.

[0031] Therefore, in one or more example aspects, specific implementations and / or use cases, the described functions may be implemented with hardware, software, or any combination thereof. If implemented with software, the functions may be stored or encoded as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media. Storage media may be any available medium that can be accessed by a computer. By way of example, such computer-readable media may include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of these types of computer-readable media, or any other medium that can be used to store computer-executable code in the form of instructions or data structures that can be accessed by a computer.

[0032] Although various aspects, specific implementations and / or use cases are described in this application by the illustration of some examples, additional or different aspects, specific implementations and use cases may be generated in many different arrangements and scenarios. The various aspects, specific implementations and / or use cases described herein can be implemented across many different platform types, devices, systems, shapes, sizes and packaging arrangements. For example, aspects, specific implementations and / or use cases can be generated via integrated chip specific implementations and other devices based on non-module components (e.g., end-user equipment, vehicles, communication equipment, computing equipment, industrial equipment, retail / purchase equipment, medical equipment, artificial intelligence (AI) enabled devices, etc.). Although some examples may be specifically for use cases or applications, or may not be specifically for use cases or applications, the described examples may have a wide range of applicability. Aspects, specific implementations and / or use cases may be in the range from chip-level or modular components to non-modular, non-chip-level specific implementations, and further to the range of aggregated, distributed or original equipment manufacturer (OEM) devices or systems in conjunction with one or more technologies herein. In some practical environments, the equipment in conjunction with the various aspects and features described may also include additional components and features for implementing and practicing the various aspects claimed and described. For example, the transmission and reception of wireless signals necessarily include multiple components for analog and digital purposes (e.g., hardware components including antennas, RF chains, power amplifiers, modulators, buffers, processors, interleavers, adders / accumulators, etc.) The various techniques described herein can be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, aggregated or disaggregated components, end-user devices, etc., of various sizes, shapes, and configurations.

[0033] The deployment of a communication system (such as a 5G NR system) may be arranged with various components or constituent parts in a variety of ways. In a 5G NR system or network, a network node, a network entity, a mobility element of a network, a radio access network (RAN) node, a core network node, a network element or a network equipment (such as a base station (BS), or one or more units (or one or more components) that perform base station functionality may be implemented in an aggregated architecture or a decomposed architecture. For example, a BS (such as a Node B (NB), an evolved NB (eNB), an NR BS, a 5G NB, an access point (AP), a transmit receive point (TRP) or a cell, etc.) may be implemented as an aggregated base station (also referred to as an independent BS or a monolithic BS) or a decomposed base station.

[0034] A converged base station may be configured to utilize a radio protocol stack physically or logically integrated within a single RAN node. A decomposed base station may be configured to utilize a protocol stack physically or logically distributed between two or more units, such as one or more central or centralized units (CUs), one or more distributed units (DUs), or one or more radio units (RUs). In some aspects, a CU may be implemented within a RAN node, and one or more DUs may be co-located with the CU, or alternatively, may be geographically or virtually distributed in one or more other RAN nodes. A DU may be implemented to communicate with one or more RUs. Each of a CU, a DU, and a RU may be implemented as a virtual unit, i.e., a virtual central unit (VCU), a virtual distributed unit (VDU), or a virtual radio unit.

[0035] Base station operation or network design may take into account the aggregated nature of base station functionality. For example, a disaggregated base station may be used in an integrated access backhaul (IAB) network, an open radio access network (O-RAN (network configuration such as that initiated by the O-RAN Alliance)), or a virtualized radio access network (vRAN, also known as a cloud radio access network (C-RAN)). Decomposition may include distributing functionality across two or more units at various physical locations, as well as virtually distributing functionality of at least one unit, which may enable flexibility in network design. Various units of a disaggregated base station or disaggregated RAN architecture may be configured for wired or wireless communication with at least one other unit.

[0036] Figure 11 is a diagram 100 illustrating an example of a wireless communication system and an access network. The illustrated wireless communication system includes a disaggregated base station architecture. The disaggregated base station architecture may include one or more CUs 110 that may communicate directly with a core network 120 via a backhaul link, or indirectly with the core network 120 through one or more disaggregated base station units, such as a near real-time (near RT) RAN intelligent controller (RIC) 125 via an E2 link, or a non-real-time (non-RT) RIC 115 associated with a service management and orchestration (SMO) framework 105, or both. The CU 110 may communicate with one or more DUs 130 via corresponding midhaul links, such as an F1 interface. The DU 130 may communicate with one or more RUs 140 via corresponding fronthaul links. The RU 140 may communicate with corresponding UEs 104 via one or more radio frequency (RF) access links. In some implementations, a UE 104 may be served simultaneously by multiple RUs 140.

[0037] Each of the units (i.e., CU 110, DU 130, RU 140, and near-RT RIC 125, non-RT RIC 115, and SMO framework 105) may include or be coupled to one or more interfaces configured to receive or send signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the units or an associated processor or controller that provides instructions to the communication interface of the unit may be configured to communicate with one or more of the other units via a transmission medium. For example, the units may include a wired interface configured to receive or send signals to one or more of the other units on a wired transmission medium. Additionally, the units may include a wireless interface that may include a receiver, a transmitter, or a transceiver (such as an RF transceiver) configured to receive or send signals, or both, to one or more of the other units on a wireless transmission medium.

[0038] In some aspects, CU 110 may host one or more higher layer control functions. Such control functions may include radio resource control (RRC), packet data convergence protocol (PDCP), service data adaptation protocol (SDAP), etc. Each control function may be implemented using an interface that is configured to communicate signals with other control functions hosted by CU 110. CU 110 may be configured to handle user plane functionality (i.e., central unit-user plane (CU-UP)), control plane functionality (i.e., central unit-control plane (CU-CP)), or a combination thereof. In some specific implementations, CU 110 may be logically split into one or more CU-UP units and one or more CU-CP units. When implemented in an O-RAN configuration, the CU-UP unit may communicate bidirectionally with the CU-CP unit via an interface (such as an E1 interface). As needed, CU 110 may be implemented to communicate with DU 130 for network control and signaling.

[0039] DU 130 may correspond to a logical unit that includes one or more base station functions for controlling the operation of one or more RUs 140. In some aspects, DU 130 may host one or more of a radio link control (RLC) layer, a medium access control (MAC) layer, and one or more high physical (PHY) layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, etc.) depending at least in part on a functional split such as that defined by 3GPP. In some aspects, DU 130 may also host one or more low PHY layers. Each layer (or module) may be implemented using an interface that is configured to communicate signals with other layers (and modules) hosted by DU 130 or with control functions hosted by CU 110.

[0040] The lower layer functionality may be implemented by one or more RUs 140. In some deployments, the RU 140 controlled by the DU 130 may correspond to a logical node that hosts RF processing functions or low PHY layer functions (such as performing fast Fourier transform (FFT), inverse FFT (iFFT), digital beamforming, physical random access channel (PRACH) extraction and filtering, etc.), or both, based at least in part on functional splitting (such as lower layer functional splitting). In such an architecture, the RU 140 may be implemented to handle over-the-air (OTA) communications with one or more UEs 104. In some specific implementations, real-time and non-real-time aspects of control plane and user plane communications with the RU 140 may be controlled by the corresponding DU 130. In some scenarios, this configuration may enable the implementation of the DU 130 and the CU 110 in a cloud-based RAN architecture (such as a vRAN architecture).

[0041] The SMO framework 105 may be configured to support RAN deployment and provisioning of non-virtualized network elements and virtualized network elements. For non-virtualized network elements, the SMO framework 105 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements, which may be managed via an operation and maintenance interface (such as an O1 interface). For virtualized network elements, the SMO framework 105 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) 190) to perform network element lifecycle management (such as instantiating virtualized network elements) via a cloud computing platform interface (such as an O2 interface). Such virtualized network elements may include, but are not limited to, CU 110, DU 130, RU 140, and near-RT RIC 125. In some specific implementations, the SMO framework 105 may communicate with hardware aspects of the 4G RAN (such as an open eNB (O-eNB) 111) via the O1 interface. Additionally, in some specific implementations, the SMO framework 105 may communicate directly with one or more RUs 140 via the O1 interface. The SMO framework 105 may also include a non-RT RIC 115 configured to support the functionality of the SMO framework 105 .

[0042] The non-RT RIC 115 may be configured to include logic functions that enable non-real-time control and optimization of RAN elements and resources, artificial intelligence (AI) / machine learning (ML) (AI / ML) workflows including model training and updating, or policy-based guidance of applications / features in the near-RT RIC 125. The non-RT RIC 115 may be coupled to or communicate with the near-RT RIC 125 (such as via an A1 interface). The near-RT RIC 125 may be configured to include logic functions that enable near-real-time control and optimization of RAN elements and resources via data collection and actions through an interface (such as via an E2 interface) that connects one or more CUs 110, one or more DUs 130, or both, and the O-eNB with the near-RT RIC 125.

[0043] In some implementations, in order to generate an AI / ML model to be deployed in the near-RT RIC 125, the non-RT RIC 115 may receive parameters or external enrichment information from an external server. Such information may be utilized by the near-RT RIC 125 and may be received from a non-network data source or from a network function at the SMO framework 105 or the non-RT RIC 115. In some examples, the non-RT RIC 115 or the near-RT RIC 125 may be configured to tune RAN behavior or performance. For example, the non-RT RIC 115 may monitor long-term trends and patterns of performance and employ AI / ML models to perform corrective actions through the SMO framework 105 (such as via reconfiguration of O1) or via the creation of RAN management policies (such as A1 policies).

[0044] At least one of the CU 110, the DU 130, and the RU 140 may be referred to as a base station 102. Therefore, the base station 102 may include one or more of the CU 110, the DU 130, and the RU 140 (each component is indicated by a dotted line to indicate that each component may be included in the base station 102, or may not be included in the base station). The base station 102 provides an access point to the core network 120 for the UE 104. The base station 102 may include a macro cell (a high-power cellular base station) and / or a small cell (a low-power cellular base station). Small cells include femto cells, pico cells, and micro cells. A network including both small cells and macro cells may be referred to as a heterogeneous network. A heterogeneous network may also include a home evolved Node B (eNB) (HeNB), which may provide services to a restricted group referred to as a closed subscriber group (CSG). The communication link between RU 140 and UE 104 may include uplink (UL) (also known as reverse link) transmission from UE 104 to RU 140 and / or downlink (DL) (also known as forward link) transmission from RU 140 to UE 104. The communication link may use multiple-input multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming and / or transmission diversity. The communication link may be through one or more carriers. For each carrier allocated in a carrier aggregation of up to Yx MHz (x component carriers) for transmission in each direction, the base station 102 / UE 104 may use a spectrum of up to Y MHz (e.g., 5MHz, 10MHz, 15MHz, 20MHz, 100MHz, 400MHz, etc.) bandwidth. The carriers may or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL ​​compared to UL). The component carrier may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as a primary cell (PCell) and the secondary component carrier may be referred to as a secondary cell (SCell).

[0045] Some UEs 104 may communicate with each other using a device-to-device (D2D) communication link 158. The D2D communication link 158 may use DL / UL wireless wide area network (WWAN) spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). The D2D communication may be through a variety of wireless D2D communication systems, such as, for example, Bluetooth, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR.

[0046] The wireless communication system may also include a Wi-Fi AP 150 that communicates with a UE 104 (also referred to as a Wi-Fi station (STA)) via a communication link 154, for example, in a 5 GHz unlicensed spectrum, etc. When communicating in an unlicensed spectrum, the UE 104 / AP 150 may perform a clear channel assessment (CCA) to determine whether a channel is available prior to communication.

[0047] The electromagnetic spectrum is typically subdivided into various categories, bands, channels, etc. based on frequency / wavelength. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz). Although a portion of FR1 is greater than 6 GHz, FR1 is often (interchangeably) referred to as the “sub-6 GHz” band in various documents and articles. A similar naming issue sometimes occurs with respect to FR2, which is often (interchangeably) referred to as the “millimeter wave” band in documents and articles, although it is different from the extremely high frequency (EHF) band (30 GHz–300 GHz) that is identified as the “millimeter wave” band by the International Telecommunication Union (ITU).

[0048] Frequencies between FR1 and FR2 are generally referred to as mid-band frequencies. Recent 5G NR research has identified the operating bands for these mid-band frequencies as frequency range designation FR3 (7.125 GHz–24.25 GHz). The bands falling within FR3 can inherit FR1 characteristics and / or FR2 characteristics, and therefore can effectively extend the features of FR1 and / or FR2 to mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operations to more than 52.6 GHz. For example, three higher operating bands have been identified as frequency range designations FR2-2 (52.6 GHz–71 GHz), FR4 (71 GHz–114.25 GHz), and FR5 (114.25 GHz–300 GHz). Each of these higher frequency bands falls within the EHF band.

[0049] In view of the above, unless otherwise specified, if the term "6 GHz or less" is used in this document, it can broadly refer to frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. In addition, unless otherwise specified, if the term "millimeter wave" is used in this document, it can broadly refer to frequencies that may include mid-band frequencies, may be within FR2, FR4, FR2-2 and / or FR5, or may be within the EHF band.

[0050] The base station 102 and the UE 104 may each include multiple antennas (such as antenna elements, antenna panels, and / or antenna arrays) to facilitate beamforming. The base station 102 may send a beamformed signal 182 to the UE 104 in one or more transmit directions. The UE 104 may receive the beamformed signal from the base station 102 in one or more receive directions. The UE 104 may also send a beamformed signal 184 to the base station 102 in one or more transmit directions. The base station 102 may receive the beamformed signal from the UE 104 in one or more receive directions. The base station 102 / UE 104 may perform beam training to determine the best receive direction and transmit direction for each of the base station 102 / UE 104. The transmit direction and receive direction of the base station 102 may be the same or different. The transmit direction and receive direction of the UE 104 may be the same or different.

[0051] The base station 102 may include and / or be referred to as a gNB, a Node B, an eNB, an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmit receive point (TRP), a network node, a network entity, a network equipment, or some other suitable term. The base station 102 may be implemented as an integrated access backhaul (IAB) node, a relay node, a sidelink node, an aggregated (monolithic) base station with a baseband unit (BBU) (including a CU and a DU) and a RU, or as a disaggregated base station including one or more of a CU, a DU, and / or a RU. A set of base stations that may include disaggregated base stations and / or aggregated base stations may be referred to as a next generation (NG) RAN (NG-RAN).

[0052] The core network 120 may include an access and mobility management function (AMF) 161, a session management function (SMF) 162, a user plane function (UPF) 163, a unified data management (UDM) 164, one or more location servers 168, and other functional entities. AMF 161 is a control node that handles signaling between UE 104 and core network 120. AMF 161 supports registration management, connection management, mobility management, and other functions. SMF 162 supports session management and other functions. UPF 163 supports packet routing, packet forwarding, and other functions. UDM 164 supports the generation of authentication and key agreement (AKA) credentials, user identity handling, access authorization, and subscription management. One or more location servers 168 are illustrated as including a gateway mobile location center (GMLC) 165 and a location management function (LMF) 166. However, in general, the one or more location servers 168 may include one or more location / positioning servers, which may include one or more of the GMLC 165, the LMF 166, the positioning determination entity (PDE), the serving mobile location center (SMLC), the mobile positioning center (MPC), etc. The GMLC 165 and the LMF 166 support UE location services. The GMLC 165 provides an interface for clients / applications (e.g., emergency services) to access UE positioning information. The LMF 166 receives measurement results and assistance information from the NG-RAN and the UE 104 via the AMF 161 to calculate the positioning of the UE 104. The NG-RAN may determine the positioning of the UE 104 using one or more positioning methods. Positioning the UE 104 may involve signal measurements, positioning estimates, and optional speed calculations based on these measurements. Signal measurements may be performed by the UE 104 and / or the serving base station 102. The measured signals may be based on a satellite positioning system (SPS) 170 (e.g., one or more of a global navigation satellite system (GNSS), a global positioning system (GPS), a non-terrestrial network (NTN), or other satellite positioning / location systems), LTE signals, wireless local area network (WLAN) signals, Bluetooth signals, a terrestrial beacon system (TBS), sensor-based information (e.g., an atmospheric pressure sensor, a motion sensor), an NR enhanced cell ID (NR E-CID) method, NR signals (e.g., multi-round trip time (multi-RTT), DL angle of departure (DL-AoD), DL time difference of arrival (DL-TDOA), UL time difference of arrival (UL-TDOA), and UL angle of arrival (UL-AoA) positioning), and / or one or more of other systems / signals / sensors.

[0053] Examples of UE 104 include cellular phones, smart phones, session initiation protocol (SIP) phones, laptops, personal digital assistants (PDAs), satellite radios, global positioning systems, multimedia devices, video devices, digital audio players (e.g., MP3 players), cameras, game consoles, tablet computers, smart devices, wearable devices, vehicles, electric meters, gas pumps, large or small kitchen appliances, healthcare equipment, implants, sensors / actuators, displays, or any other similarly functional devices. Some of the UEs 104 may be referred to as IoT devices (e.g., parking meters, gas pumps, toasters, vehicles, heart monitors, etc.). UE 104 may also be referred to as stations, mobile stations, subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless terminals, remote terminals, mobile phones, user agents, mobile clients, clients, or some other suitable terminology. In some scenarios, the term UE may also be applied to one or more supporting devices, such as in a device cluster arrangement. One or more of these devices may access the network collectively and / or individually.

[0054] Reference again Figure 1 In certain aspects, the UE 104 may include a Doppler measurement component 198 configured to measure the Doppler of signals received from a plurality of transmitters (e.g., SVs, base stations, TRPs, etc.). In one configuration, the Doppler measurement component 198 may be configured to receive signals from one or more entities via a receiver. In such a configuration, the Doppler measurement component 198 may determine whether each received signal is a multipath signal based on a Doppler shift measurement. In such a configuration, the Doppler measurement component 198 may de-weight or exclude one or more of the received signals when estimating the positioning of the UE based on whether the corresponding received signal is determined to be a multipath signal.

[0055] In another configuration, the Doppler measurement component 198 can be configured to receive signals from one or more entities via a receiver. In this configuration, the Doppler measurement component 198 can determine whether each received signal is a multipath signal based on the Doppler shift measurement. In this configuration, the Doppler measurement component 198 can transmit measurement information associated with one or more of the received signals via a transmitter, the measurement information indicating, at least in part, whether each of the one or more signals is a multipath signal.

[0056] Figure 2A FIG200 is a diagram illustrating an example of a first subframe within a 5G NR frame structure. Figure 2B FIG230 is a diagram illustrating an example of DL channels within a 5G NR subframe. Figure 2C FIG250 is a diagram illustrating an example of a second subframe within a 5G NR frame structure. Figure 2D FIG280 is a diagram illustrating an example of UL channels within a 5G NR subframe. The 5G NR frame structure may be frequency division duplex (FDD), where for a particular set of subcarriers (carrier system bandwidth), subframes within that subcarrier set are dedicated to either DL or UL, or may be time division duplex (TDD), where for a particular set of subcarriers (carrier system bandwidth), subframes within that subcarrier set are dedicated to both DL and UL. Figure 2A , Figure 2C In the example provided, the 5G NR frame structure is assumed to be TDD, where subframe 4 is configured with slot format 28 (most of which are DL), where D is DL, U is UL, and F is flexible between DL / UL, and subframe 3 is configured with slot format 1 (all of which are UL). Although subframes 3 and 4 are shown as having slot formats 1 and 28, respectively, any particular subframe may be configured with any of the various available slot formats 0 to 61. Slot formats 0 and 1 are both DL and both UL, respectively. Other slot formats 2-61 include a mix of DL, UL, and flexible symbols. The slot format is configured for the UE via a received slot format indicator (SFI) (dynamically configured via DL control information (DCI) or semi-statically / statically configured via radio resource control (RRC) signaling). Note that the following description also applies to the 5G NR frame structure as TDD.

[0057] FIG. 2A to FIG. 2D The frame structure is illustrated, and various aspects of the present disclosure may be applicable to other wireless communication technologies that may have different frame structures and / or different channels. A frame (10ms) may be divided into 10 subframes of the same size (1ms). Each subframe may include one or more time slots. A subframe may also include a microslot, which may include 7, 4 or 2 symbols. Each time slot may include 14 or 12 symbols, depending on whether the cyclic prefix (CP) is conventional or extended. For a conventional CP, each time slot may include 14 symbols, and for an extended CP, each time slot may include 12 symbols. The symbol on the DL may be a CP orthogonal frequency division multiplexing (OFDM) (CP-OFDM) symbol. The symbol on the UL may be a CP-OFDM symbol (for high throughput scenarios) or a discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbol (also known as a single carrier frequency division multiple access (SC-FDMA) symbol) (for power-limited scenarios; limited to single-stream transmission). The number of time slots within a subframe is based on the CP and parameter set. The parameter set defines the subcarrier spacing (SCS) and effectively defines the symbol length / duration, which is equal to 1 / SCS.

[0058]

[0059] For normal CP (14 symbols / slot), different parameter sets μ0 to 4 allow 1, 2, 4, 8, and 16 slots per subframe, respectively. For extended CP, parameter set 2 allows 4 slots per subframe. Accordingly, for normal CP and parameter set μ, there are 14 symbols / slot and 2 μ timeslots / subframe. The subcarrier spacing can be equal to 2 μ *15kHz, where μ is parameter set 0 to 4. Therefore, the subcarrier spacing for parameter set μ=0 is 15kHz, and the subcarrier spacing for parameter set μ=4 is 240kHz. The symbol length / duration is inversely related to the subcarrier spacing. FIG. 2A to FIG. 2D An example of a parameter set μ=2 with a normal CP of 14 symbols per slot and 4 slots per subframe is provided. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is about 16.67 μs. Within a frame set, there may be one or more different bandwidth parts (BWPs) that are frequency-division multiplexed (see Figure 2B ). Each BWP may have a specific parameter set and CP (normal or extended).

[0060] A resource grid may be used to represent a frame structure. Each slot includes a resource block (RB) (also referred to as a physical RB (PRB)) extending over 12 consecutive subcarriers. The resource grid is divided into a plurality of resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0061] like Figure 2A As illustrated, some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include a demodulation RS (DM-RS) (indicated as R for a particular configuration, but other DM-RS configurations are possible) and a channel state information reference signal (CSI-RS) for channel estimation at the UE. The RS may also include a beam measurement RS (BRS), a beam refinement RS (BRRS), and a phase tracking RS (PT-RS).

[0062] Figure 2BExamples of various DL channels within a subframe of a frame are illustrated. A physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs) (e.g., 1, 2, 4, 8, or 16 CCEs), each CCE including six RE groups (REGs), each REG including 12 consecutive REs in an OFDM symbol of an RB. A PDCCH within a BWP may be referred to as a control resource set (CORESET). The UE is configured to monitor PDCCH candidates in a PDCCH search space (e.g., a common search space, a UE-specific search space) during a PDCCH monitoring opportunity on a CORESET, wherein the PDCCH candidates have different DCI formats and different aggregation levels. Additional BWPs may be located at higher and / or lower frequencies on the channel bandwidth. A primary synchronization signal (PSS) may be within symbol 2 of a particular subframe of a frame. The PSS is used by UE 104 to determine subframe / symbol timing and physical layer identification. A secondary synchronization signal (SSS) may be within symbol 4 of a particular subframe of a frame. The SSS is used by the UE to determine the physical layer cell identity group number and the radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine the physical cell identifier (PCI). Based on the PCI, the UE can determine the location of the DM-RS. The physical broadcast channel (PBCH) carrying the master information block (MIB) can be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block (also referred to as an SS block (SSB)). The MIB provides the system frame number (SFN) and the number of RBs in the system bandwidth. The physical downlink shared channel (PDSCH) carries user data, broadcast system information such as system information blocks (SIBs) that are not sent via the PBCH, and paging messages.

[0063] like Figure 2C As illustrated, some of the REs carry DM-RS (indicated as R for a particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE may send a DM-RS for a physical uplink control channel (PUCCH) and a DM-RS for a physical uplink shared channel (PUSCH). The PUSCH DM-RS may be sent in the first or first two symbols of the PUSCH. Depending on whether a short PUCCH or a long PUCCH is sent and depending on the specific PUCCH format used, the PUCCH DM-RS may be sent in different configurations. The UE may send a sounding reference signal (SRS). The SRS may be sent in the last symbol of a subframe. The SRS may have a comb structure, and the UE may send the SRS on one of the teeth of the comb. The SRS may be used by the base station for channel quality estimation to achieve frequency-dependent scheduling of the UL.

[0064] Figure 2DExamples of various UL channels within a subframe of a frame are illustrated. The PUCCH may be located at a position as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicators (CQI), precoding matrix indicators (PMI), rank indicators (RI), and hybrid automatic repeat request (HARQ) acknowledgement (ACK) (HARQ-ACK) feedback (i.e., one or more HARQ ACK bits indicating one or more ACKs and / or negative ACKs (NACKs)). The PUSCH carries data and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and / or UCI.

[0065] Figure 3 370 is a block diagram of a base station 310 communicating with a UE 350 in an access network. In the DL, Internet Protocol (IP) packets may be provided to a controller / processor 375. The controller / processor 375 implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller / processor 375 provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with delivery of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0066] The transmit (TX) processor 316 and receive (RX) processor 370 implement layer 1 functionality associated with various signal processing functions. Layer 1 (which includes the physical (PHY) layer) may include error detection on the transport channel, forward error correction (FEC) coding / decoding of the transport channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The TX processor 316 handles the mapping to the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-order phase shift keying (M-PSK), M-order quadrature amplitude modulation (M-QAM)). The decoded and modulated symbols can then be divided into parallel streams. Subsequently, each stream can be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., a pilot) in the time domain and / or frequency domain, and then combined using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially pre-coded to generate multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine the coding and modulation schemes, as well as for spatial processing. Channel estimates may be derived from reference signals and / or channel state feedback sent by the UE 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318Tx. Each transmitter 318Tx may modulate a radio frequency (RF) carrier for transmission using a corresponding spatial stream.

[0067] At the UE 350, each receiver 354Rx receives a signal through its corresponding antenna 352. Each receiver 354Rx recovers the information modulated onto the RF carrier and provides the information to a receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover any spatial streams destined for the UE 350. If multiple spatial streams are destined for the UE 350, they can be merged into a single OFDM symbol stream by the RX processor 356. The RX processor 356 then converts the OFDM symbol stream from the time domain to the frequency domain using a fast Fourier transform (FFT). The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier and the reference signal are recovered and demodulated by determining the most likely signal constellation point sent by the base station 310. These soft decisions can be based on channel estimates calculated by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally sent on the physical channel by the base station 310. The data and control signals are then provided to the controller / processor 359, which implements layer 3 and layer 2 functionality.

[0068] The controller / processor 359 may be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer readable medium. In the UL, the controller / processor 359 provides demultiplexing between transport channels and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets. The controller / processor 359 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operations.

[0069] Similar to the functions described in conjunction with DL transmissions performed by the base station 310, the controller / processor 359 provides RRC layer functionality associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functionality associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functionality associated with delivery of upper layer PDUs, error correction through ARQ, concatenation, segmentation and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0070] The TX processor 368 may use channel estimates derived by the channel estimator 358 from a reference signal or feedback sent by the base station 310 to select appropriate coding and modulation schemes and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antennas 352 via corresponding transmitters 354Tx. Each transmitter 354Tx may modulate an RF carrier with a corresponding spatial stream for transmission.

[0071] UL transmissions are processed at the base station 310 in a manner similar to that described in conjunction with the receiver functionality at the UE 350. Each receiver 318Rx receives a signal through its respective antenna 320. Each receiver 318Rx recovers information modulated onto an RF carrier and provides the information to the RX processor 370.

[0072] The controller / processor 375 may be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer readable medium. In the UL, the controller / processor 375 provides demultiplexing between transport channels and logical channels, packet reassembly, decryption, header decompression, control signal processing to recover IP packets. The controller / processor 375 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operations.

[0073] At least one of the TX processor 368, the RX processor 356, and the controller / processor 359 may be configured to perform operations related to Figure 1 The Doppler measurement component 198 combines various aspects.

[0074] Figure 4 4 is a diagram illustrating an example of UE positioning based on reference signal measurements (which may also be referred to as “network-based positioning”) according to various aspects of the present disclosure. UE 404 may be at time T SRS_TX UL-SRS 412 is sent and at time T PRS_RX A DL positioning reference signal (PRS) (DL-PRS) 410 is received. TRP 406 may be at time T SRS_RX Receive UL-SRS 412 and at time T PRS_TX 410. UE 404 may receive DL-PRS 410 before transmitting UL-SRS 412, or may transmit UL-SRS 412 before receiving DL-PRS 410. In both cases, a positioning server (e.g., location server 168) or UE 404 may determine the UL-SRS 412 based on ||T SRS_RX –T PRS_TX |–|T SRS_TX –T PRS_RX || determines RTT 414. Thus, multi-RTT positioning may utilize UE Rx-Tx time difference measurements (i.e., |T SRS_TX –T PRS_RX |) and DL-PRS reference signal received power (RSRP) (DL-PRS-RSRP), and the measured TRP Rx-Tx time difference measurement (ie, |T SRS_RX –T PRS_TX |) and UL-SRS-RSRP. The UE 404 measures the UE Rx-Tx time difference measurement (and optionally the DL-PRS-RSRP of the received signal) using the assistance data received from the positioning server, and the TRP 402, 406 measures the gNB Rx-Tx time difference measurement (and optionally the UL-SRS-RSRP of the received signal) using the assistance data received from the positioning server. These measurements may be used at the positioning server or the UE 404 to determine the RTT, which is used to estimate the position of the UE 404. Other methods for determining the RTT are possible, such as, for example, using DL-TDOA and / or UL-TDOA measurements.

[0075] DL-AoD positioning may utilize the measured DL-PRS-RSRP of downlink signals received from multiple TRPs 402, 406 at the UE 404. The UE 404 measures the DL-PRS-RSRP of the received signals using assistance data received from a positioning server, and the resulting measurements, along with the departure azimuth angle (A-AoD), departure zenith angle (Z-AoD), and other configuration information, are used to position the UE 404 relative to neighboring TRPs 402, 406.

[0076] DL-TDOA positioning may utilize DL Reference Signal Time Difference (RSTD) (and optionally DL-PRS-RSRP) of downlink signals received from multiple TRPs 402, 406 at the UE 404. The UE 404 measures the DL RSTD (and optionally DL-PRS-RSRP) of the received signals using assistance data received from a positioning server, and the resulting measurements are used along with other configuration information to position the UE 404 relative to neighboring TRPs 402, 406.

[0077] UL-TDOA positioning may utilize the UL relative time of arrival (RTOA) (and optionally UL-SRS-RSRP) of uplink signals sent from the UE 404 at multiple TRPs 402, 406. The TRPs 402, 406 measure the UL-RTOA (and optionally UL-SRS-RSRP) of the received signals using assistance data received from a positioning server, and the resulting measurements are used along with other configuration information to estimate the position of the UE 404.

[0078] UL-AoA positioning may utilize the measured azimuth angle of arrival (A-AoA) and zenith angle of arrival (Z-AoA) of uplink signals sent from the UE 404 at multiple TRPs 402, 406. The TRPs 402, 406 measure the A-AoA and Z-AoA of the received signals using assistance data received from a positioning server, and the resulting measurements, along with other configuration information, are used to estimate the position of the UE 404. For purposes of this disclosure, positioning operations in which a UE provides measurements to a base station / positioning entity / server for use in calculating the UE's position may be described as "UE-assisted," "UE-assisted positioning," and / or "UE-assisted position calculation," while positioning operations in which a UE measures and calculates its own position may be described as "UE-based," "UE-based positioning," and / or "UE-based position calculation."

[0079] Additional positioning methods may be used to estimate the position of the UE 404, such as, for example, UE-side UL-AoD and / or DL-AoA. Note that data / measurements from various techniques may be combined in various ways to increase accuracy, determine and / or enhance certainty, supplement / complete measurements, and / or replace / provide missing information.

[0080] A device equipped with a Global Navigation Satellite System (GNSS) receiver may determine its position based on GNSS positioning. GNSS is a network of satellites that broadcasts timing and orbit information used for navigation and positioning measurements. GNSS may include groups of satellites, called clusters, that broadcast signals (which may be referred to as GNSS signals) to control stations and users of the GNSS. Based on the broadcast signals, a user may be able to determine its position (e.g., via trilateration). For the purposes of this disclosure, a device (e.g., UE) equipped with a GNSS receiver or capable of receiving GNSS signals may be referred to as a GNSS device, and a device (such as a satellite) capable of sending GNSS signals may be referred to as a space vehicle (SV).

[0081] Figure 5 5 is a diagram illustrating an example of GNSS positioning according to various aspects of the present disclosure. A GNSS device 506 may estimate its position and time based at least in part on data (e.g., GNSS signals 504) received from a plurality of space vehicles (SVs) 502, wherein each SV 502 may carry a record of its position and time and may send the data (e.g., the record) to the GNSS device 506. Each SV 502 may also include a clock that is synchronized with other clocks of the SV and with a ground clock. If the SV 502 detects a deviation from the time kept on the ground, the SV 502 may correct for it. The GNSS device 506 may also include a clock, but the clock of the GNSS device 506 may be less stable and accurate than the clock of the SV 502.

[0082] Because the speed of radio waves may be constant and independent of satellite speed, the time delay between the time when SV 502 transmits GNSS signal 504 and the time when GNSS device 506 receives GNSS signal 504 may be proportional to the distance from SV 502 to GNSS device 506. In some examples, GNSS device 506 may use a minimum of four SVs to calculate / estimate one or more unknown quantities associated with positioning (e.g., three positioning coordinates and a clock bias from satellite time, etc.).

[0083] Each SV 502 may continuously broadcast a GNSS signal 504 (e.g., with a modulated carrier wave) that may include a pseudo-random code (e.g., a sequence of ones and zeros) known to the GNSS device 506, and may also include a message including the time of transmission and the SV position at that time. In other words, each GNSS signal 504 may carry two types of information: time and carrier wave (e.g., with a modulated waveform of an input signal to be transmitted electromagnetically). Based on the GNSS signal 504 received from the SV 502, the GNSS device 506 may measure the time of arrival (TOA) of the GNSS signal 504 and estimate the time of flight (TOF) of the GNSS signal 504. Then, based on the TOF, the GNSS device 506 may calculate its three-dimensional position and clock bias, and the GNSS device 506 may determine its position on the earth. For example, the position of the GNSS device 506 may be converted into latitude, longitude, and altitude relative to an ellipsoidal earth model. These coordinates may be displayed on a display such as a moving map, or recorded or used by some other system (such as a vehicle guidance system).

[0084] Although the distance between the GNSS device and the SV can be estimated based on the time it takes for the GNSS signal to reach the GNSS device, the signal sequence of the SV may be delayed relative to the sequence of the GNSS device. Therefore, in some examples, a delay may be applied to the sequence of the GNSS device so that the two sequences are aligned. For example, in order to estimate the delay, the GNSS device may align the pseudo-random binary sequence included in the SV signal with an internally generated pseudo-random binary sequence. Since the GNSS signal of the SV takes time to reach the GNSS device, the sequence of the SV may be delayed relative to the sequence of the GNSS device. By gradually delaying the sequence of the GNSS device, the two sequences can eventually be aligned. The accuracy of GNSS positioning may depend on various factors, such as SV geometry, GNSS signal blockage, atmospheric conditions and / or GNSS receiver design features / quality. For example, the accuracy of the GNSS receiver used by a smart phone or smart watch may be lower than that of the GNSS receiver used by vehicles and exploration equipment.

[0085] The accuracy of GNSS-based positioning may depend on various factors, such as satellite geometry, signal blockage, atmospheric conditions, and / or receiver design features / quality. For example, the GNSS receiver used by a smart phone or smart watch may have lower accuracy than the GNSS receiver used by vehicles and exploration equipment. In order to improve the accuracy of GNSS positioning (e.g., from several meters to several centimeters), real-time kinematic (RTK) technology or mechanism can be used for positioning equipment. RTK is a technology or mechanism that can be used by positioning equipment (e.g., UE, exploration equipment, automotive GNSS system, etc.) to improve positioning accuracy. For example, based on RTK, the positioning device can use the correction information of the base station to reduce several error sources in the PR and CP measurements of the GNSS receiver of the positioning device, which may include satellite orbits, satellite clocks, atmospheric errors, etc. Therefore, the positioning device can achieve better accuracy.

[0086] Figure 6 600 is a diagram illustrating an example of RTK positioning according to various aspects of the present disclosure. In one example, at least two receivers may be used in association with RTK positioning, wherein at least one of the receivers may be fixed, which may be referred to as a base station 603 (or RTK base station), and at least one other receiver may be mobile (e.g., freely movable), which may be referred to as a rover or rover device 604 (e.g., a GNSS / GPS receiver, UE, rover, etc.). In other words, an RTK system may include a base station and a rover, wherein the base station may be a fixed receiver whose position is known.

[0087] The range between the SV 602 (e.g., GNSS / GPS satellite) and the rover device 604 or between the SV 602 and the base station 603 may be calculated by determining the number of carrier cycles between the SV 602 and the rover device 604 or the base station 603 and multiplying the number by the carrier wavelength 608 of the carrier wave 606 (e.g., carrier signal) transmitted by the SV 602. For example, if the SV 602 transmits the carrier wave 606 having a wavelength 608 of ten (10) meters, and the rover device 604 receives the carrier wave 606 and determines that there are five hundred (600) carrier cycles between the SV 602 and the rover device 604, the rover device 604 may calculate the distance between the SV 602 and the rover device 604 by multiplying the determined number of carrier cycles (e.g., 600) by the carrier wavelength 608 (e.g., 10 meters), which may be five kilometers (e.g., 600×10=6000). Similarly, base station 603 may also receive carrier wave 606 from SV 602 and determine the range of the carrier wave from satellite 602 based on the wavelength 608 of carrier wave 606 and the number of carrier wave cycles between base station 603 and SV 602. Rover device 604 and / or base station 603 may calculate the range (e.g., distance) between rover device 604 / base station 603 and multiple (e.g., four or more) SVs (e.g., SV 601 and SV 602) to determine their geographic locations (e.g., their positions on the earth).

[0088] During RTK positioning, the rover device 604 (e.g., UE, client device, etc.) may undergo an “ambiguity resolution” process to determine the number of carrier cycles between the SV 602 and the rover device 604. In other words, when the rover device 604 receives carrier from the SV 602, the rover device 604 may take time to calculate how many carrier cycles exist between the SV 602 and the rover device 604. In some examples, a GNSS receiver with a more complex or high-end antenna / hardware (such as an automotive-grade antenna) may be able to resolve ambiguities in a relatively short time (e.g., within seconds), while a GNSS receiver with a less complex or low-end antenna / hardware (such as an antenna for a mobile phone and / or smart watch) may take longer (e.g., 10 minutes to 30 minutes or more) to resolve ambiguities. In some examples, the ambiguities may also be referred to as “integer ambiguities.”

[0089] In some examples, the range calculated by the rover device 604 may include errors due to SV clocks and ephemeris, as well as ionospheric delays and tropospheric delays, etc. In addition, since the rover device 604 is more likely to be mobile, the quality of the signal / carrier received from each SV may change as the rover device moves from one location to another. For example, if the rover device 604 moves from an open sky area to an area with buildings, the signal from one or more SVs 601 / 602 may be blocked / reflected by the buildings. Therefore, the range calculated by the rover device 604 may begin to drift and may include errors.

[0090] On the other hand, since the base station 603 is likely to be fixed, have a known position, and the base station 603 may be equipped with a more complex and high-end GNSS receiver, the base station 603 may be able to maintain an accurate calculation of the range compared to the mobile station device 604. For example, the base station 603 may be configured to be located at a site (e.g., an open sky area) with minimal environmental impacts (such as interference and multipath). Therefore, under RTK positioning, the base station 603 may be configured to calculate its position by using a signal received from a SV (e.g., SV 601 / 602) based on carrier phase measurements, and then the base station 603 may compare the calculated position with its known position to identify whether there is any error. If the base station 603 identifies that there is an error, the base station 603 may generate correction data 610 (or correction signal) and send the correction data 610 to the mobile station device 604 to assist the mobile station device 604 in correcting the error. For example, since the mobile station device 604 can be generally configured to be located near the base station 603 (e.g., within 6 miles, 12 miles, etc.), the mobile station device 604 is likely to encounter errors similar to those of the base station 603 (e.g., similar ionospheric delays and tropospheric delays). Therefore, the mobile station device 604 can use the correction data 610 from the base station 603 to improve its own positioning calculated from the GNSS cluster to achieve centimeter accuracy. In other words, the base station can be configured to remain in a fixed / known position and send correction data to one or more mobile station devices, and the one or more mobile station devices can use the correction data to increase the accuracy of their positioning and the speed of error correction. Therefore, the mobile station device 604 can use an algorithm that combines ambiguity resolution and differential correction to determine its positioning. The positioning accuracy that the mobile station device 604 can achieve may depend on its distance from the base station 603 and the accuracy of the differential correction (e.g., correction data 610).

[0091] In some scenarios, non-line-of-sight (NLOS) GNSS measurements (e.g., measurements of GNSS signals made by a GNSS device) may reduce outdoor position fix accuracy, such as in urban areas. For example, if there are obstacles between the SV and the GNSS device, such as physical structures (e.g., buildings, tunnels) and terrain (e.g., mountains), the GNSS signals received by the GNSS device may be weakened and / or include offsets / delays. Similarly, for combined Figure 4 As discussed for network-based positioning, NLOS measurements (eg, measurements of positioning reference signals) may also degrade the accuracy of UE positioning, such as by causing delays to the reference signals.

[0092] Figure 7 700 is a diagram illustrating an example of NLOS GNSS measurements in an urban area according to various aspects of the present disclosure. A GNSS device 706 may receive a GNSS signal (which may be referred to as an LOS signal) from an SV 702 based on a line-of-sight (LOS) condition. However, due to obstruction and environmental conditions, the GNSS device 706 may receive a GNSS signal (which may be referred to as an NLOS signal) from another SV 704 based on an NLOS condition, wherein the GNSS signal from the SV 704 may penetrate and / or bounce off one or more objects (e.g., buildings, trees, etc.) before reaching the GNSS device 706. Since an NLOS signal may generally take longer to reach the GNSS device than an LOS signal, the NLOS signal may include excessive delay. Therefore, when multiple GNSS measurements are based on NLOS conditions, the positioning accuracy and speed of the GNSS device may be reduced. This in turn may reduce the efficiency and accuracy of certain location-based service (LBS) applications (such as navigation applications and ride-sharing applications). In addition, the reduction in accuracy may be more significant during the initial time and warm start of the GNSS device when the positioning uncertainty is large (e.g., about one kilometer). In some examples, the continuous lock accuracy may also be reduced. Although the example illustrated in Figure 700 is applicable to GNSS-based positioning, similar NLOS conditions may also be applicable to network-based positioning.

[0093] In some examples, the services provided for GNSS-based positioning and network-based positioning may be referred to as "positioning, navigation, and timing (PNT) services." As the name implies, PNT services mainly include three elements: positioning, navigation, and timing. The positioning element may refer to the ability to accurately and precisely determine a person's position and orientation in two dimensions (or three dimensions when specified) with reference to a standard geodetic system. The navigation element may refer to the ability to determine the current and desired positioning (relative or absolute) and apply corrections to heading, orientation, and velocity to achieve the desired positioning anywhere in the world (from underground to the ground and from the ground to space). The timing element may refer to the ability to obtain and maintain accurate and precise time according to a standard (e.g., Coordinated Universal Time or UTC) anywhere in the world and within user-defined timeliness parameters. Timing may also include time transmission. For the purposes of this disclosure, GNSS-based positioning and network-based positioning may be collectively referred to as radio frequency (RF)-based positioning technology or RF-based positioning services.

[0094] For RF-based positioning techniques, signal multipath effects (e.g., combined with Figure 7 The NLOS condition discussed above) is generally considered to be one of the main error sources that may affect positioning performance. Signal multipath effect or multipath effect may refer to a signal sent from a transmitter reaching a receiver via more than one path. For example, a GNSS signal may reach the antenna of a GNSS receiver via multiple different paths, which may affect both pseudorange and carrier phase measurements at the GNSS receiver. Therefore, for many positioning devices, how to deal with multipath effects (e.g., such as in a signal challenge environment) has always been an important aspect of device design. For example, for GNSS-based positioning (or GNSS-based PNT), a GNSS receiver may detect and / or mitigate multipath effects based on pseudorange (PR) unilateral de-weighting, signal-to-noise ratio measurement, three-dimensional (3D) mapping assistance, machine learning (ML), or a combination thereof.

[0095] The various aspects presented herein can improve the performance and accuracy of RF-based positioning. The various aspects presented herein can enable a device to use RF Doppler measurements to detect and mitigate multipath effects in RF-based positioning. RF-based positioning may include satellite navigation (e.g., GNSS, low earth orbit (LEO) satellites, etc.), ground positioning systems (e.g., network-based positioning associated with 5G NR, 4G LTE, etc.) and / or indoor positioning (e.g., Wi-Fi-based positioning, ultra-wideband (UWB) positioning, Bluetooth positioning, etc.). Since Doppler measurements may be ubiquitous in most RF-based systems, and additional hardware infrastructure may not be specified, the various aspects presented herein may be applicable to a wide range of RF-based positioning technologies.

[0096] Doppler measurements may include measurements of the Doppler effect / frequency shift. The Doppler effect / frequency shift may refer to the change in the frequency of a wave relative to an observer that is moving relative to the source of the wave. For example, as the source of the wave moves toward the observer, each successive wave crest may be transmitted from a location closer to the observer than the crest of the previous wave. Therefore, each wave may arrive at the observer slightly less than the previous wave. Therefore, the time between successive wave crests arriving at the observer decreases, resulting in an increase in frequency. As they travel, the distance between successive wave fronts decreases, so the waves may "bunch together." On the other hand, if the source of the wave moves away from the observer, each wave may be transmitted from a location farther from the observer than the previous wave, so the arrival time between successive waves increases, thereby reducing the frequency. Then, the distance between successive wave fronts increases, so the waves may instead "spread out."

[0097] Figure 8 800 is a diagram illustrating an example of a GNSS device detecting multipath effects based on Doppler measurements in a GNSS scenario according to various aspects of the present disclosure. In one aspect of the present disclosure, a GNSS device 802 (which may be a UE) may receive a signal transmitted from one or more SVs, which may include a first SV 804 and a second SV 806. The GNSS device 802 may then measure a Doppler shift of the received signal. For example, the Doppler shift may be based on is measured, where Δv is the relative velocity between the GNSS device 802 and the SV (eg, Δv = c is the speed of light (eg, RF speed), and f 0 is the transmission frequency. If the velocity of the GNSS device 802 has been determined, the line-of-sight Doppler may be calculated. In addition, the residual of the Doppler shift (which may also be referred to as the Doppler residual or the Doppler shift residual) may be obtained based on calculating the difference between the expected Doppler shift and the measured Doppler shift (e.g., Doppler residual=expected Doppler shift−measured Doppler shift).

[0098] Thus, based on the measured Doppler shift or the calculated Doppler residual, the GNSS device 802 may determine whether the received signal is a multipath signal. For example, if the Doppler shift residual of the received signal exceeds a Doppler shift threshold (or the measured Doppler shift of the received signal exceeds the expected Doppler shift by a certain margin / threshold), the received signal may be a multipath signal. For example, as shown at 810 and 814, the GNSS device 802 may measure the Doppler shift of the signal transmitted from the first SV 804 and the second SV 806, and the GNSS device 802 may calculate the residual of the Doppler shift and compare the calculated Doppler shift residual with the Doppler shift threshold. The various aspects presented herein may be used for positioning associated with smartphones, car positioning, unmanned aerial vehicles (UAVs) in deep urban areas (e.g., metropolitan areas), wearable devices, and / or connected smart systems (IoT), etc.

[0099] In one aspect, the Doppler shift threshold may be based on information from another GNSS device (such as a Figure 6 804, the Doppler shift threshold may be based on an expected Doppler shift (e.g., a constant value measured by the base station) plus and minus (+ / -) a Doppler shift range (e.g., 10 Hz, 20 Hz, etc.). In another example, the Doppler shift threshold may be based on a range, where the range may be different for different SVs (e.g., for a first SV 804, an upper limit of 20 Hz and a lower limit of -20 Hz; for a second SV 806, an upper limit of -20 Hz and a lower limit of -45 Hz, etc.). It should be noted that the various aspects presented herein are applicable to all types of GNSS positioning technologies and are not limited to RTK.

[0100] In another aspect, the Doppler shift threshold may be configured to be dynamic. For example, the Doppler shift threshold (or the Doppler shift range of the Doppler shift threshold) may be configured as a function of the measured Doppler shift / Doppler residual. If the measured Doppler shift / Doppler residual is within a first range (e.g., -20 Hz to -40 Hz), the GNSS device 802 may apply a first Doppler shift threshold / range (-15 Hz to -45 Hz), and if the measured Doppler shift / Doppler residual is within a second range (e.g., -10 Hz to -40 Hz), the GNSS device 802 may apply a second Doppler shift threshold / range (e.g., -5 Hz to -45 Hz). In another example, the Doppler shift range may be configured as a function of the speed of the GNSS device 802. For example, if the GNSS device 802 is moving at a lower speed (e.g., below 65 miles per hour), the Doppler shift range may be smaller (e.g., plus and minus 10 Hz), and if the GNSS device 802 is moving at a higher speed (e.g., above 65 miles per hour), the Doppler shift range may be larger (e.g., plus and minus 20 Hz), etc. In another example, the Doppler shift range may be configured as a function of the environment surrounding the GNSS device 802. For example, if the GNSS device 802 is in an environment where signal blockage or reflections are less likely to occur (e.g., open sky or shallow urban environment), the Doppler shift threshold / range may be lower, and if the GNSS device 802 is in an environment where signal blockage or reflections are more likely to occur (e.g., metropolitan or deep urban environment), the Doppler shift threshold / range may be larger.

[0101] Then, as shown at 812, if the calculated Doppler shift residual of the signal received from the first SV 804 exceeds the Doppler shift threshold or the measured Doppler shift exceeds the expected Doppler shift by a certain margin / threshold (for a certain period of time or duration), the first SV 804 can determine that the signal received from the first SV 804 is a multipath signal. On the other hand, as shown at 814, since the Doppler shift residual of the signal sent from the second SV 806 does not exceed the Doppler shift threshold, the GNSS device 802 can determine that the signals sent from the second SV 806 are not subject to multipath effects (e.g., these signals are LOS signals / non-multipath signals). Thus, various aspects presented herein can enable the GNSS device 802 or a location entity / server to detect multipath signals based on Doppler residual or Doppler shift, where the Doppler residual is equal to the expected (or modeled) Doppler shift minus the measured Doppler shift. If the velocity of the GNSS device 802 is accurate, the expected Doppler shift can be determined. In some examples, the velocity of the GNSS device 802 can be estimated from other sources, such as Doppler shifts from other RF ranging systems, inertial measurement unit (IMU) sensors, or vehicle sensors, etc. The Doppler residual can be composed of multipath terms and noise terms (e.g., Gaussian white noise). The multipath term can generally show a one-sided effect on the velocity estimate. That is, multipath may cause the estimated velocity to be less than the actual velocity. Detection of such a pattern can indicate the presence of multipath. For the purposes of this disclosure, a multipath signal can refer to a NLOS signal (e.g., a signal received only via reflections, such as Fig. 9 918 and 920 of FIG. 1 ) or a signal including at least one NLOS signal (eg, a signal received via a combination of LOS and NLOS signals, such as Figure 8 818 of FIG. 1 ). Therefore, in some scenarios, the term multipath signal and the term NLOS signal may be used interchangeably throughout the specification. However, this does not mean that the two effects (e.g., multipath effect and NLOS effect) are the same. In some examples, if a signal is received only via reflections, the signal may not be interpreted as a multipath signal. On the other hand, a non-multipath signal may refer to a LOS signal (e.g., a directly received signal, such as Figure 8 820 of FIG. 1 ).

[0102] Based on determining whether the signals received from different SVs are multipath signals or non-multipath signals (or LOS signals or NLOS signals), the GNSS device 802 (e.g., for UE-based positioning) or a network entity / server (e.g., for UE-assisted positioning) may mark, de-weight, and / or exclude one or more signals received from one or more SVs. For example, if the GNSS device 802 is performing a positioning session with multiple SVs including a first SV 804, the GNSS device 802 or the network entity / server may exclude measurements associated with the first SV 804 for use in positioning calculations / estimations because the signals from the first SV 804 are determined to be multipath signals. In another example, instead of excluding measurements associated with the first SV 804, the GNSS device 802 or the network entity / server may de-weight the measurements, such as by providing less weight to the measurements than measurements obtained from non-multipath signals. For example, the measurements of each signal from the first SV 804 may be de-weighted by a factor W (e.g., 0≤W<1), where W may be based on a difference between a measured Doppler shift / Doppler shift residual and a threshold Doppler shift. In other words, W may be configured as a function of a difference (e.g., |D-DT|) between a measured Doppler shift / Doppler shift residual and a threshold Doppler shift, such as being inversely proportional to the difference (e.g., a higher difference is associated with a lower factor value, a lower difference is associated with a higher factor value, etc.). In another example, W may be configured as a function of the number of SVs that are transmitting non-multipath / LOS signals. For example, when there are more SVs transmitting non-multipath / LOS signals, a lower factor W (e.g., a higher de-weighting) may be applied to measurements associated with multipath / NLOS signals, and when there are fewer SVs transmitting non-multipath / LOS signals, a higher factor W (e.g., a lower de-weighting) may be applied to measurements associated with multipath / NLOS signals, and when there are fewer SVs transmitting non-multipath / LOS signals, a higher factor W (e.g., a lower de-weighting) may be applied to measurements associated with multipath / NLOS signals, and so on. Thus, the first number N may be equal to the number of one or more SVs, the second number M may be equal to the number of SVs in the one or more base stations from which signals determined to be multipath signals are received, and W may be based on a comparison of the first number N and the second number M. In another example, the GNSS device 802 may simply flag measurements (e.g., as multipath / NLOS signals or non-multipath / LOS signals), and a corresponding location server / entity (e.g., location server 816) may exclude or de-weight these measurements based on these flags.

[0103] In another example, instead, the GNSS device 802 or the network entity / server may give more weight to non-multipath or LOS measurements. For example, if the GNSS device 802 determines that the signal from the second SV 806 is a LOS signal, the GNSS device 802 may give a heavier weight (e.g., W>1) to the measurements associated with the second SV 806.

[0104] In another aspect, there may be more than one Doppler shift threshold, wherein the GNSS device 802 may de-weight the measurements of the SV if the measurement (e.g., Doppler residual or measured Doppler shift) is above a first Doppler shift threshold but below a second Doppler shift threshold, and the GNSS device 802 may exclude the measurements if the measurements are above the second Doppler shift threshold. For example, a first upper Doppler threshold of 20 Hz and a second upper Doppler threshold of 40 Hz may be defined for the first SV 804. The GNSS device 802 may de-weight the measurements if the Doppler measurements from the first SV 804 are within 20 Hz to 40 Hz. On the other hand, if the Doppler measurements from the first SV 804 are above 40 Hz, the GNSS device 802 may exclude these measurements (e.g., the measurements associated with the first SV 804 may be ignored).

[0105] Thus, various aspects presented herein can enable a GNSS device or location entity / server to mitigate positioning errors by examining Doppler residuals. If the Doppler residual exceeds a predefined threshold (Limit_1), the Doppler can be considered an outlier and the corresponding signal can be marked as strong multipath. Ranging measurements such as pseudorange and / or carrier phase of the signal can be removed. If the Doppler residual is less than Limit_1 but greater than another threshold (Limit_2) corresponding to the noise level of the Doppler measurement. The ranging measurements (PR / CP) can be de-weighted based on the Doppler residual value.

[0106] Although combined Figure 8 The described example shows that the GNSS device 802 can determine whether the signal from the SV is a multipath signal or a non-multipath signal, but this determination can also be made by the location entity / server (e.g., for UE-assisted positioning). For example, the GNSS device 802 can send measurement information or positioning estimates associated with the de-weighted or excluded signal to the location entity / server 816 for processing at the location entity / server. In another example, the GNSS device 802 can send information indicating whether the measurement information or positioning estimate is associated with a multipath signal to the location entity / server 816 (e.g., sending flag information to the location entity / server for processing at the location server).

[0107] Fig. 9900 is a diagram illustrating an example of a UE detecting multipath effects based on Doppler measurements in a ground scenario according to various aspects of the present disclosure. In another aspect of the present disclosure, during a network-based positioning session, a UE 902 (which may be static or mobile) (e.g., a vehicle UE, a pedestrian UE, etc.) may receive signals (e.g., RF signals, reference signals, PRS, etc.) transmitted from one or more base stations or transmit receive points (TRPs) of base stations, which may include a first base station 904 (or a first TRP) and a second base station 906 (or a second TRP), such as in combination with Figure 4 Then, UE 902 may measure the Doppler shift of the received reference signal. For example, the Doppler shift may be based on is measured, where Δv is the relative speed between UE 902 and the base station (e.g., c is the speed of light (eg, RF speed), and f 0 is the transmission frequency. If the speed of UE 902 can be determined, such as based on a sensor (e.g., GNSS, IMU, vehicle speed sensor (VSS), etc.), the deviation of the Doppler measured at UE 902 from the expected (modeled) value may indicate whether the received signal may be subject to multipath effects (e.g., line-of-sight Doppler may be calculated). In other words, the residual of the Doppler shift may be obtained based on calculating the difference between the expected Doppler shift and the measured Doppler shift (e.g., Doppler residual=expected Doppler shift-measured Doppler shift).

[0108] Thus, based on the measured Doppler shift or the calculated Doppler residual, the UE 902 may determine whether the received signal is a multipath signal, for example, if the Doppler shift residual of the received signal exceeds a Doppler shift threshold (or the measured Doppler shift of the received signal exceeds the expected Doppler shift by a certain margin / threshold), then the received signal may be a multipath signal. For example, as shown at 910 and 914, the UE 902 may measure the Doppler shift of the signal transmitted from the first base station 904 and the second base station 906, and the UE 902 may calculate the residual of the Doppler shift and compare the calculated Doppler shift residual with the Doppler shift threshold. The detection of whether a signal may be subject to multipath effects may include scenarios such as a signal reflected from a moving object (e.g., a truck) and then received by the UE 902 when the UE 902 is static (as shown at 918), a signal reflected from a static object (e.g., a building) (as shown at 920), and / or a signal reflected from a mixture of static objects and moving objects. Various aspects presented herein may be used for positioning associated with smartphones, automobile positioning, unmanned aerial vehicles (UAVs) in deep urban areas (e.g., metropolitan areas), wearable devices, and / or connected smart systems (IoT), etc.

[0109] In one aspect, the Doppler shift threshold may be based on the Doppler of an expected (modeled) value, which may be obtained via measurements from another UE or a device with higher capabilities. For example, as shown at 908, the Doppler shift threshold may be based on the expected Doppler shift (e.g., a constant value) plus and minus (+ / -) a Doppler shift range (e.g., 10 Hz, 20 Hz, etc.). In another example, the Doppler shift threshold may be based on a range, where the range may be different for different base stations (e.g., for the first base station 904, the upper limit is 20 Hz and the lower limit is -20 Hz; for the second base station 906, the upper limit is -20 Hz and the lower limit is -45 Hz, etc.).

[0110] On the other hand, the Doppler shift threshold can be dynamic. For example, the Doppler shift threshold (or the Doppler shift range of the Doppler shift threshold) can be configured as a function of the measured Doppler shift / Doppler residual. If the measured Doppler shift / Doppler residual is within a first range (e.g., -20 Hz to -40 Hz), the UE 902 can apply a first Doppler shift threshold / range (-15 Hz to -45 Hz), and if the measured Doppler shift / Doppler residual is within a second range (e.g., -10 Hz to -40 Hz), the UE 902 can apply a second Doppler shift threshold / range (e.g., -5 Hz to -45 Hz). In another example, the Doppler shift range can be configured as a function of the speed of the UE 902. For example, if the UE 902 is moving at a lower speed (e.g., less than 65 miles per hour), the Doppler shift range may be smaller (e.g., plus and minus 10 Hz), and if the UE 902 is moving at a higher speed (e.g., greater than 65 miles per hour), the Doppler shift range may be larger (e.g., plus and minus 20 Hz), etc. In another example, the Doppler shift range may be configured as a function of the environment surrounding the UE 902. For example, if the UE 902 is in an environment where signal blockage or reflections are less likely to occur (e.g., an open sky or shallow urban environment), the Doppler shift threshold / range may be lower, while if the UE 902 is in an environment where signal blockage or reflections are more likely to occur (e.g., a metropolitan or deep urban environment), the Doppler shift threshold / range may be larger.

[0111] Then, as shown at 912, if the calculated Doppler shift residual of the signal received from the first base station 904 exceeds the Doppler shift threshold or the measured Doppler shift exceeds the expected Doppler shift by a certain margin / threshold (for a certain period of time or duration), the first base station 904 can determine that the signal received from the first base station 904 is a multipath signal. On the other hand, as shown at 914, since the Doppler shift residual of the signal sent from the second base station 906 does not exceed the Doppler shift threshold, the UE 902 can determine that the signals sent from the second base station 906 are not subject to multipath effects (e.g., these signals are LOS signals / non-multipath signals). Therefore, various aspects presented herein can enable the UE 902 or the location entity / server 916 to detect multipath signals based on the Doppler residual, where the Doppler residual can be equal to the expected (or modeled) Doppler minus the measured Doppler.

[0112] Based on determining whether the signals received from different base stations are multipath signals or non-multipath signals (or LOS signals or NLOS signals), the UE 902 (e.g., for UE-based positioning) or a network entity / server (e.g., for UE-assisted positioning) may mark, de-weight, and / or exclude one or more signals received from one or more base stations. For example, if the UE 902 is performing a positioning session with multiple base stations including the first base station 904, the UE 902 or the network entity / server (e.g., the location server 916) may exclude measurements associated with the first base station 904 for positioning calculation / estimation because the signals from the first base station 904 are determined to be multipath signals. In another example, instead of excluding measurements associated with the first base station 904, the UE 902 or the network entity / server may de-weight the measurements, such as by providing less weight to the measurements than measurements obtained from non-multipath signals. For example, the measurement of each signal from the first base station 904 can be de-weighted by a factor W (e.g., 0≤W<1), where W can be based on the difference between the measured Doppler shift / Doppler shift residual and the threshold Doppler shift. In other words, W can be configured as a function of the difference between the measured Doppler shift / Doppler shift residual and the threshold Doppler shift (e.g., |D-DT|), such as being inversely proportional to the difference (e.g., a higher difference is associated with a lower factor value, while a lower difference is associated with a higher factor value, etc.). In another example, W can be configured to be a function of the number of base stations that are transmitting non-multipath / LOS signals. For example, when there are more base stations transmitting non-multipath / LOS signals, a lower factor W (e.g., a higher de-weighting) can be applied to measurements associated with multipath / NLOS signals, and when there are fewer base stations transmitting non-multipath / LOS signals, a higher factor W (e.g., a lower de-weighting) can be applied to measurements associated with multipath / NLOS signals, and when there are fewer base stations transmitting non-multipath / LOS signals, a higher factor W (e.g., a lower de-weighting) can be applied to measurements associated with multipath / NLOS signals, and so on. Thus, the first number N may be equal to the number of one or more base stations, the second number M may be equal to the number of base stations in the one or more base stations from which signals determined to be multipath signals are received, and W may be based on a comparison of the first number N and the second number M. In another example, the UE 902 may simply mark the measurements (e.g., as multipath / NLOS signals or non-multipath / LOS signals), and the corresponding network entity / server (e.g., location server 916) may exclude or de-weight the measurements based on these markings.

[0113] In another example, as an alternative, the UE 902 or network entity / server may give more weight to non-multipath or LOS measurements. For example, if the UE 902 determines that the signal from the second base station 906 is a LOS signal, the UE 902 may give a heavier weight (e.g., W>1) to the measurement associated with the second base station 906.

[0114] In another aspect, there may be more than one Doppler shift threshold, wherein if the measurement (e.g., Doppler residual or measured Doppler shift) is above a first Doppler shift threshold but below a second Doppler shift threshold, the UE 902 may de-weight the measurement of the base station, and if the measurement is above the second Doppler shift threshold, the UE 902 may exclude the measurement. For example, a first upper Doppler threshold of 20 Hz and a second upper Doppler threshold of 40 Hz may be associated with the first base station 904. If the Doppler measurement from the first base station 904 is within 20 Hz to 40 Hz, the UE 902 may de-weight the measurement. On the other hand, if the Doppler measurement from the first base station 904 is above 40 Hz, the UE 902 may exclude these measurements (e.g., the measurement associated with the first base station 904 may be ignored).

[0115] Thus, various aspects presented herein can enable a UE or location entity / server to mitigate positioning errors by examining the Doppler residual. If the Doppler residual exceeds a predefined threshold (Limit_1), the Doppler can be considered an outlier and the corresponding signal can be marked as strong multipath. Measurements associated with multipath signals can then be removed. If the Doppler residual is less than Limit_1 but greater than another threshold (Limit_2) corresponding to the noise level of the Doppler measurement. The measurements can be de-weighted based on the Doppler residual value.

[0116] Although combined Fig. 9 The described example shows that the UE 902 can determine whether the signal from the base station is a multipath signal or a non-multipath signal, but the determination can also be made by the location entity / server (e.g., for UE-assisted positioning). For example, the UE 902 can send measurement information or positioning estimates associated with the de-weighted or excluded signal to the location entity / server 916 for processing at the location entity / server. In another example, the UE 902 can send information indicating whether the measurement information or positioning estimate is associated with a multipath signal to the location entity / server 916 (e.g., sending flag information to the location entity / server for processing at the location server).

[0117] Fig.10 1000 is a flow chart of a method of positioning estimation. The method may be performed by a UE (e.g., UE 104, 404, 902; GNSS device 506, 706, 802; rover device 604; apparatus 1204). The method may enable a UE to use RF Doppler measurements to detect and mitigate multipath effects in RF-based UE positioning.

[0118] At 1002, the UE may receive, via a receiver, a signal from one or more entities, such as a Figure 8 and Fig. 9 For example, the GNSS device 802 may receive GNSS signals from the first SV 804 and the second SV 806. The reception of the signals may be performed by, for example Fig.12 The Doppler measurement component 198 and / or the transceiver 1222 of the device 1204 may be used to perform the operation.

[0119] In one example, the one or more entities include one or more satellites, one or more base stations, or a combination thereof.

[0120] At 1004, the UE may determine whether each received signal is a multipath signal based on the Doppler shift measurement, such as in combination with Figure 8 and Fig. 9 For example, the GNSS device 802 may determine whether each GNSS signal received from the first SV 804 and the second SV 806 is a multipath signal based on the Doppler shift measurement. The determination of whether each received signal is a multipath signal based on the Doppler shift measurement may be performed by, for example Fig.12 The Doppler measurement component 198 of the device 1204 is used to perform.

[0121] In one example, as shown at 1008, to determine whether each received signal is a multipath signal based on the Doppler shift measurement, the UE may measure the Doppler shift of the received signal, and the UE may determine whether a residual of the measured Doppler shift of the received signal exceeds a threshold Doppler shift, wherein when the residual of the measured Doppler shift of the received signal exceeds the threshold Doppler shift, the received signal is determined to be a multipath signal, such as in combination with Figure 8 and Fig. 9 as described.

[0122] In one example, the threshold Doppler shift may be equal to the expected Doppler shift plus or minus the Doppler shift range.

[0123] In another example, the Doppler shift range is a constant value.

[0124] In another example, the Doppler shift range is a function of the measured Doppler shift.

[0125] In another example, the Doppler shift range is a function of the residual of the measured Doppler shift.

[0126] In another example, the Doppler shift range is a function of the speed of the UE.

[0127] In another example, the Doppler shift range is a function of the environment of the UE.

[0128] In another example, the multipath signal includes a non-line-of-sight signal.

[0129] At 1006, the UE may de-weight or exclude one or more of the received signals when estimating the location of the UE based on whether the corresponding received signal is determined to be a multipath signal, such as in combination with Figure 8 and Fig. 9 For example, the GNSS device 802 may de-weight or exclude one or more signals received from the first SV 804 when estimating the position of the GNSS device 802 based on the signal from the first SV 804 being a multipath signal. The de-weighting or exclusion of the signal may be performed, for example, by Fig.12 The Doppler measurement component 198 of the device 1204 is used to perform.

[0130] In one example, as shown at 1010, in order to de-weight or exclude one or more of the received signals when estimating the location of the UE based on whether the corresponding received signal is determined to be a multipath signal, the UE may exclude each of the one or more of the received signals when estimating the location of the UE when the corresponding signal is determined to be a multipath signal, such as in combination with Figure 8 and Fig. 9 as described.

[0131] In one example, as shown at 1012, in order to de-weight or exclude one or more of the received signals when estimating the positioning of the UE based on whether the corresponding received signal is determined to be a multipath signal, the UE may de-weight the measurement of each of the one or more of the received signals by W when estimating the positioning of the UE when the corresponding signal is determined to be a multipath signal, where 0≤W<1, such as in combination with Figure 8 and Fig. 9 In this example, W is based on the difference between the measured Doppler shift and the threshold Doppler shift. In another example, the first number N is equal to the number of one or more entities, the second number M is equal to the number of transmitters of the one or more entities from which the signal determined to be multipath is received, and W is based on a comparison of the first number N and the second number M.

[0132] At 1014, the UE may transmit, via a transmitter, measurement information or a UE positioning estimate associated with the de-weighted or excluded one or more signals to at least one location server, such as in conjunction with Figure 8 and Fig. 9 For example, the GNSS device 802 may send measurement information or UE location estimates associated with the de-weighted or excluded GNSS signals to the location server 816. The sending of measurement information or UE location estimates associated with the de-weighted or excluded one or more signals may be performed by, for example, Fig.12The Doppler measurement component 198 and / or the transceiver 1222 of the device 1204 in the embodiment may be performed. In such an example, the UE may send information indicating whether the measurement information or the UE positioning estimate is associated with one or more multipath signals to at least one location server.

[0133] Fig.11 1100 is a flow chart of a method of positioning estimation. The method may be performed by a UE (e.g., UE 104, 404, 902; GNSS device 506, 706, 802; rover device 604; apparatus 1204). The method may enable a UE to use RF Doppler measurements to detect and mitigate multipath effects in RF-based UE positioning.

[0134] At 1102, the UE may receive, via a receiver, a signal from one or more entities, such as a Figure 8 and Fig. 9 For example, the GNSS device 802 may receive GNSS signals from the first SV 804 and the second SV 806. The reception of the signals may be performed by, for example Fig.12 The Doppler measurement component 198 and / or the transceiver 1222 of the device 1204 may be used to perform the operation.

[0135] In one example, the one or more entities include one or more satellites, one or more base stations, or a combination thereof.

[0136] At 1104, the UE may determine whether each received signal is a multipath signal based on the Doppler shift measurement, such as in combination with Figure 8 and Fig. 9 For example, the GNSS device 802 may determine whether each GNSS signal received from the first SV 804 and the second SV 806 is a multipath signal based on the Doppler shift measurement. The determination of whether each received signal is a multipath signal based on the Doppler shift measurement may be performed by, for example Fig.12 The Doppler measurement component 198 of the device 1204 is used to perform.

[0137] In one example, to determine whether each received signal is a multipath signal based on Doppler shift measurement, the UE may measure the Doppler shift of the received signal, and the UE may determine whether a residual of the measured Doppler shift of the received signal exceeds a threshold Doppler shift, wherein when the residual of the measured Doppler shift of the received signal exceeds the threshold Doppler shift, the received signal is determined to be a multipath signal, such as in combination with Figure 8 and Fig. 9 as described.

[0138] In another example, the threshold Doppler shift may be equal to the expected Doppler shift plus or minus the Doppler shift range.

[0139] In another example, the Doppler shift range is a constant value.

[0140] In another example, the Doppler shift range is a function of the measured Doppler shift.

[0141] In another example, the Doppler shift range is a function of the residual of the measured Doppler shift.

[0142] In another example, the Doppler shift range is a function of the speed of the UE.

[0143] In another example, the Doppler shift range is a function of the environment of the UE.

[0144] In another example, the multipath signal includes a non-line-of-sight signal.

[0145] At 1106, the UE may de-weight or exclude one or more of the received signals when estimating the location of the UE based on whether the corresponding received signal is determined to be a multipath signal, such as in combination with Figure 8 and Fig. 9 For example, the GNSS device 802 may de-weight or exclude one or more signals received from the first SV 804 when estimating the position of the GNSS device 802 based on the signal from the first SV 804 being a multipath signal. The de-weighting or exclusion of the signal may be performed, for example, by Fig.12 The Doppler measurement component 198 of the device 1204 is used to perform.

[0146] In one example, in order to de-weight or exclude one or more of the received signals when estimating the positioning of the UE based on whether the corresponding received signal is determined to be a multipath signal, the UE may exclude each of the one or more of the received signals when estimating the positioning of the UE when the corresponding signal is determined to be a multipath signal, such as in combination with Figure 8 and Fig. 9 as described.

[0147] In another example, in order to de-weight or exclude one or more of the received signals when estimating the positioning of the UE based on whether the corresponding received signal is determined to be a multipath signal, the UE may de-weight the measurement of each of the one or more of the received signals by W when estimating the positioning of the UE when the corresponding signal is determined to be a multipath signal, where 0≤W<1, such as in combination with Figure 8 and Fig. 9In this example, W is based on the difference between the measured Doppler shift and the threshold Doppler shift. In another example, the first number N is equal to the number of one or more entities, the second number M is equal to the number of transmitters of the one or more entities from which the signal determined to be multipath is received, and W is based on a comparison of the first number N and the second number M.

[0148] In another example, the UE may send measurement information or UE positioning estimates associated with the de-weighted or excluded one or more signals to at least one location server via a transmitter, such as in conjunction with Figure 8 and Fig. 9 For example, the GNSS device 802 may send measurement information or UE location estimates associated with the de-weighted or excluded GNSS signals to the location server 816. The sending of measurement information or UE location estimates associated with the de-weighted or excluded one or more signals may be performed by, for example, Fig.12 The Doppler measurement component 198 and / or the transceiver 1222 of the device 1204 in the embodiment may be performed. In such an example, the UE may send information indicating whether the measurement information or the UE positioning estimate is associated with one or more multipath signals to at least one location server.

[0149] Fig.121200 is an example of a hardware implementation of an example device 1204. The device 1204 may be a UE, a component of a UE, or may implement UE functionality. In some aspects, the device 1204 may include a cellular baseband processor 1224 (also referred to as a modem) coupled to one or more transceivers 1222 (e.g., a cellular RF transceiver). The cellular baseband processor 1224 may include on-chip memory 1224'. In some aspects, the device 1204 may also include one or more subscriber identity module (SIM) cards 1220 and an application processor 1206 coupled to a secure digital (SD) card 1208 and a screen 1210. The application processor 1206 may include on-chip memory 1206'. In some aspects, the device 1204 may also include a Bluetooth module 1212, a WLAN module 1214, an SPS receiver 1216 (e.g., a GNSS module), one or more sensor modules 1218 (e.g., an atmospheric pressure sensor / altimeter; a motion sensor such as an inertial management unit (IMU), a gyroscope, and / or an accelerometer; light detection and ranging (LIDAR), radio-aided detection and ranging (RADAR), sound navigation and ranging (SONAR), a magnetometer, audio, and / or other technologies for positioning), an additional memory module 1226, a power source 1230, and / or a camera 1232. The Bluetooth module 1212, the WLAN module 1214, and the SPS receiver 1216 may include an on-chip transceiver (TRX) (or in some cases, only a receiver (RX)). The Bluetooth module 1212, the WLAN module 1214, and the SPS receiver 1216 may include their own dedicated antennas and / or communicate using an antenna 1280. The cellular baseband processor 1224 communicates with the UE 104 and / or with the RU associated with the network entity 1202 through the transceiver 1222 via one or more antennas 1280. The cellular baseband processor 1224 and the application processor 1206 may each include a computer-readable medium / memory 1224', 1206', respectively. The additional memory module 1226 may also be considered a computer-readable medium / memory. Each computer-readable medium / memory 1224', 1206', additional memory module 1226 may be non-transitory. The cellular baseband processor 1224 and the application processor 1206 are each responsible for general processing, including executing software stored on a computer-readable medium / memory. The software, when executed by the cellular baseband processor 1224 / application processor 1206, enables the cellular baseband processor 1224 / application processor 1206 to perform the various functions described above. The computer-readable medium / memory can also be used to store data manipulated by the cellular baseband processor 1224 / application processor 1206 when executing the software.The cellular baseband processor 1224 / application processor 1206 may be a component of the UE 350 and may include the memory 360 and / or at least one of the TX processor 368, the RX processor 356, and the controller / processor 359. In one configuration, the device 1204 may be a processor chip (modem and / or application) and include only the cellular baseband processor 1224 and / or the application processor 1206, while in another configuration, the device 1204 may be the entire UE (e.g., see. Figure 3 350) and includes additional modules of device 1204.

[0150] As discussed above, the Doppler measurement component 198 is configured to: receive signals from one or more entities via a receiver; determine whether each received signal is a multipath signal based on Doppler shift measurements; and de-weight or exclude one or more of the received signals when estimating the location of the UE based on whether the corresponding received signal is determined to be a multipath signal. The Doppler measurement component 198 may be in the cellular baseband processor 1224, the application processor 1206, or in both the cellular baseband processor 1224 and the application processor 1206. The Doppler measurement component 198 may be one or more hardware components that are specifically configured to perform the process / algorithm, implemented by one or more processors configured to perform the process / algorithm, stored in a computer-readable medium for implementation by one or more processors, or some combination thereof. As shown, the device 1204 may include a variety of components configured for various functions. In one configuration, the device 1204, and specifically the cellular baseband processor 1224 and / or the application processor 1206, includes: a component for receiving signals from one or more entities via a receiver; a component for determining whether each received signal is a multipath signal based on Doppler shift measurements; and a component for de-weighting or excluding one or more of the received signals when estimating the positioning of the UE based on whether the corresponding received signal is determined to be a multipath signal.

[0151] In one configuration, the means for determining whether each received signal is a multipath signal based on the Doppler shift measurement includes configuring the device 1204 to: measure the Doppler shift of the received signal; and determine whether the residual of the measured Doppler shift of the received signal exceeds a threshold Doppler shift, wherein when the residual of the measured Doppler shift of the received signal exceeds the threshold Doppler shift, the received signal is determined to be a multipath signal. In this configuration, the threshold Doppler shift is equal to the expected Doppler shift plus or minus a Doppler shift range. In this configuration, the Doppler shift range is a constant value, a function of the measured Doppler shift, a function of the residual of the measured Doppler shift, a function of the speed of the UE, or a function of the environment of the UE.

[0152] In another configuration, the means for de-weighting or excluding one or more of the received signals when estimating the positioning of the UE based on whether the corresponding received signal is determined to be a multipath signal includes configuring the device 1204 to: when the corresponding signal is determined to be a multipath signal, exclude each of the one or more of the received signals when estimating the positioning of the UE.

[0153] In another configuration, the means for de-weighting or excluding one or more of the received signals when estimating the location of the UE based on whether the corresponding received signal is determined to be a multipath signal includes configuring the device 1204 to: when the corresponding signal is determined to be a multipath signal, de-weight the measurement of each of the one or more of the received signals by W when estimating the location of the UE, where 0≤W<1. In this configuration, W is based on the difference between the measured Doppler shift and the threshold Doppler shift. In another configuration, the first number N is equal to the number of one or more entities, the second number M is equal to the number of transmitters from which the one or more entities that are determined to be multipath signals are received, and W is based on a comparison of the first number N and the second number M.

[0154] In another configuration, the apparatus 1204 further comprises means for sending, via the transmitter, to at least one location server measurement information or UE location estimate associated with the de-weighted or excluded one or more signals. In this configuration, the apparatus 1204 further comprises means for sending, to at least one location server, information indicating whether the measurement information or UE location estimate is associated with one or more multipath signals.

[0155] In another configuration, the multipath signal includes a non-line-of-sight signal.

[0156] The means may be a component 198 of the apparatus 1204 configured to perform the functions recited by the means. As described above, the apparatus 1204 may include a TX processor 368, an RX processor 356, and a controller / processor 359. Thus, in one configuration, the means may be the TX processor 368, the RX processor 356, and / or the controller / processor 359 configured to perform the functions recited by the means.

[0157] Fig.13 1300 is a flow chart of a method for positioning estimation. The method may be performed by a UE (e.g., UE 104, 404, 902; GNSS device 506, 706, 802; rover device 604; apparatus 1204). The method may enable the UE to indicate to a location server whether a signal received from one or more entities is a multipath signal.

[0158] At 1302, the UE may receive, via a receiver, a signal from one or more entities, such as a Figure 8 and Fig. 9 For example, the GNSS device 802 may receive GNSS signals from the first SV 804 and the second SV 806. The reception of the signals may be performed by, for example Fig.14 The Doppler measurement component 198 and / or the transceiver 1422 of the device 1404 is performed.

[0159] In one example, the one or more entities include one or more satellites, one or more base stations, or a combination thereof.

[0160] At 1304, the UE may determine whether each received signal is a multipath signal based on the Doppler shift measurement, such as in combination with Figure 8 and Fig. 9 For example, the GNSS device 802 may determine whether each GNSS signal received from the first SV 804 and the second SV 806 is a multipath signal based on the Doppler shift measurement. The determination of whether each received signal is a multipath signal based on the Doppler shift measurement may be performed by, for example Fig.14 The Doppler measurement component 198 of the device 1404 is used to perform.

[0161] In one example, to determine whether each received signal is a multipath signal based on Doppler shift measurement, the UE may measure the Doppler shift of the received signal, and the UE may determine whether a residual of the measured Doppler shift of the received signal exceeds a threshold Doppler shift, wherein when the residual of the measured Doppler shift of the received signal exceeds the threshold Doppler shift, the received signal is determined to be a multipath signal, such as in combination with Figure 8 and Fig. 9 In this example, the threshold Doppler shift may be equal to the expected Doppler shift plus or minus a Doppler shift range. In this example, the Doppler shift range is one of: a constant value, a function of the measured Doppler shift, a function of the residual of the measured Doppler shift, a function of the speed of the UE, or a function of the environment of the UE.

[0162] In another example, the multipath signal includes a non-line-of-sight signal.

[0163] At 1306, the UE may transmit, via a transmitter, measurement information associated with one or more of the received signals, the measurement information indicating, at least in part, whether each of the one or more signals is a multipath signal, such as in combination with Figure 8 and Fig. 9For example, the GNSS device 802 may send measurement information associated with GNSS signals received from the first SV 804 and the second SV 806 to the location server 816, wherein the measurement information may at least partially indicate whether each of the one or more signals is a multipath signal (e.g., for UE-assisted positioning). The transmission of the measurement information may be performed, for example, by Fig.14 The Doppler measurement component 198 of the device 1404 is used to perform.

[0164] In one example, the measurement information also indicates a Doppler shift measurement of the one or more signals.

[0165] In another example, the measurement information is sent to a location server.

[0166] Fig.141400 is an example of a hardware implementation of an example device 1404. The device 1404 may be a UE, a component of a UE, or may implement UE functionality. In some aspects, the device 1404 may include a cellular baseband processor 1424 (also referred to as a modem) coupled to one or more transceivers 1422 (e.g., a cellular RF transceiver). The cellular baseband processor 1424 may include on-chip memory 1424'. In some aspects, the device 1404 may also include one or more subscriber identity module (SIM) cards 1420 and an application processor 1406 coupled to a secure digital (SD) card 1408 and a screen 1410. The application processor 1406 may include on-chip memory 1406'. In some aspects, the device 1404 may also include a Bluetooth module 1412, a WLAN module 1414, an SPS receiver 1416 (e.g., a GNSS module), one or more sensor modules 1418 (e.g., an atmospheric pressure sensor / altimeter; a motion sensor such as an inertial management unit (IMU), a gyroscope, and / or an accelerometer; light detection and ranging (LIDAR), radio-aided detection and ranging (RADAR), sound navigation and ranging (SONAR), a magnetometer, audio, and / or other technologies for positioning), an additional memory module 1426, a power source 1430, and / or a camera 1432. The Bluetooth module 1412, the WLAN module 1414, and the SPS receiver 1416 may include an on-chip transceiver (TRX) (or in some cases, only a receiver (RX)). The Bluetooth module 1412, the WLAN module 1414, and the SPS receiver 1416 may include their own dedicated antennas and / or communicate using an antenna 1480. The cellular baseband processor 1424 communicates with the UE 104 and / or with the RU associated with the network entity 1402 through the transceiver 1422 via one or more antennas 1480. The cellular baseband processor 1424 and the application processor 1406 may each include a computer-readable medium / memory 1424', 1406', respectively. The additional memory module 1426 may also be considered as a computer-readable medium / memory. Each computer-readable medium / memory 1424', 1406', additional memory module 1426 may be non-transitory. The cellular baseband processor 1424 and the application processor 1406 are each responsible for general processing, including executing software stored on a computer-readable medium / memory. The software, when executed by the cellular baseband processor 1424 / application processor 1406, enables the cellular baseband processor 1424 / application processor 1406 to perform the various functions described above. The computer-readable medium / memory can also be used to store data manipulated by the cellular baseband processor 1424 / application processor 1406 when executing the software.The cellular baseband processor 1424 / application processor 1406 may be a component of the UE 350 and may include the memory 360 and / or at least one of the TX processor 368, the RX processor 356, and the controller / processor 359. In one configuration, the device 1404 may be a processor chip (modem and / or application) and include only the cellular baseband processor 1424 and / or the application processor 1406, while in another configuration, the device 1404 may be the entire UE (e.g., see. Figure 3 350) and includes additional modules of device 1404.

[0167] As discussed above, the Doppler measurement component 198 is configured to: receive signals from one or more entities via a receiver; determine whether each received signal is a multipath signal based on Doppler shift measurements; and transmit measurement information associated with one or more of the received signals via a transmitter, the measurement information at least partially indicating whether each of the one or more signals is a multipath signal. The Doppler measurement component 198 may be within the cellular baseband processor 1224, the application processor 1206, or both the cellular baseband processor 1224 and the application processor 1206. The Doppler measurement component 198 may be one or more hardware components that are specifically configured to perform the process / algorithm, implemented by one or more processors configured to perform the process / algorithm, stored in a computer-readable medium for implementation by one or more processors, or some combination thereof. As shown, the device 1204 may include a variety of components configured for various functions. In one configuration, the device 1204, and specifically the cellular baseband processor 1224 and / or the application processor 1206, includes: a component for receiving signals from one or more entities via a receiver; a component for determining whether each received signal is a multipath signal based on Doppler shift measurement; and a component for sending measurement information associated with one or more of the received signals via a transmitter, the measurement information at least partially indicating whether each of the one or more signals is a multipath signal.

[0168] In one configuration, the means for determining whether each received signal is a multipath signal based on the Doppler shift measurement includes configuring the device 1204 to: measure the Doppler shift of the received signal; and determine whether the residual of the measured Doppler shift of the received signal exceeds a threshold Doppler shift, wherein when the residual of the measured Doppler shift of the received signal exceeds the threshold Doppler shift, the received signal is determined to be a multipath signal. In this configuration, the threshold Doppler shift is equal to the expected Doppler shift plus or minus a Doppler shift range. In this configuration, the Doppler shift range is a constant value, a function of the measured Doppler shift, a function of the speed of the UE, a function of the residual of the measured Doppler shift, or a function of the environment of the UE.

[0169] In another configuration, the measurement information further indicates a Doppler shift measurement of the one or more signals.

[0170] In another configuration, the measurement information is sent to a location server.

[0171] In another configuration, the multipath signal includes a non-line-of-sight signal.

[0172] The means may be a component 198 of the apparatus 1204 configured to perform the functions recited by the means. As described above, the apparatus 1204 may include a TX processor 368, an RX processor 356, and a controller / processor 359. Thus, in one configuration, the means may be the TX processor 368, the RX processor 356, and / or the controller / processor 359 configured to perform the functions recited by the means.

[0173] It should be understood that the specific order or hierarchy of the blocks in the disclosed process / flowchart is only an illustration of the exemplary method. It should be understood that the specific order or hierarchy of the blocks in the process / flowchart can be rearranged based on design preferences. In addition, some blocks can be combined or omitted. The attached method claims provide the elements of each block in a sample order, but are not limited to the specific order or hierarchy provided.

[0174] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects. Therefore, the claims are not limited to the various aspects described herein, but should be given the full scope consistent with the language claims. Unless otherwise specified, reference to an element in the singular form does not mean "one and only one", but "one or more". Terms such as "if", "when ..." and "at ..." do not mean a direct temporal relationship or reaction. That is, these phrases, such as "when ...", do not mean an instant action in response to the occurrence of an action or during the occurrence of an action, but only mean that if the condition is met, the action will occur without a specific or instantaneous time constraint to make the action occur. The word "exemplary" is used herein to mean "used as an example, instance, or illustration". Any aspect described as "exemplary" herein is not necessarily interpreted as being preferred or having an advantage over other aspects. Unless otherwise specified, the term "some" refers to one or more. Combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof" include any combination of A, B, and / or C, and may include multiple A, multiple B, or multiple C. Specifically, combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof" may be only A, only B, only C, A and B, A and C, B and C, or A and B and C, where any such combination may contain one or more members of A, B, or C. A set should be interpreted as a set of elements, where the number of elements is one or more. Thus, for a set of X, X will include one or more elements. If the first device receives data from the second device or sends data to the second device, the data may be received / sent directly between the first device and the second device, or indirectly between the first device and the second device through a collection of devices. All structural and functional equivalents of the elements throughout the various aspects described in this disclosure that are known or will later be known to a person of ordinary skill in the art are expressly incorporated herein by reference and are covered by the claims. In addition, nothing disclosed herein is intended to be dedicated to the public, regardless of whether such disclosure is explicitly stated in the claims. Words such as "module", "mechanism", "element", "device", etc. cannot replace the word "component". Therefore, no claim element will be understood as a component plus function unless the element is explicitly stated using the phrase "component for..."

[0175] As used herein, the phrase "based on" should not be interpreted as referring to a closed set of information, one or more conditions, one or more factors, etc. In other words, the phrase "based on A" (where "A" can be information, a condition, a factor, etc.) should be interpreted as "based at least on A" unless specifically stated differently.

[0176] The following aspects are merely illustrative and may be combined with other aspects or teachings described herein without limitation.

[0177] Aspect 1 is a method for positioning at a UE, the method comprising: receiving signals from one or more entities via a receiver; determining whether each received signal is a multipath signal based on Doppler shift measurement; and de-weighting or excluding one or more of the received signals when estimating the positioning of the UE based on whether the corresponding received signal is determined to be a multipath signal.

[0178] Aspect 2 is a method according to Aspect 1, wherein determining whether each received signal is a multipath signal based on the Doppler frequency shift measurement includes: measuring the Doppler frequency shift of the received signal; and determining whether the residual of the measured Doppler frequency shift of the received signal exceeds a threshold Doppler frequency shift, wherein when the residual of the measured Doppler frequency shift of the received signal exceeds the threshold Doppler frequency shift, the received signal is determined to be a multipath signal.

[0179] Aspect 3 is a method according to aspect 2, wherein the threshold Doppler shift is equal to the expected Doppler shift plus or minus the Doppler shift range.

[0180] Aspect 4 is a method according to aspect 3, wherein the Doppler shift range is a constant value.

[0181] Aspect 5 is a method according to aspect 3, wherein the Doppler shift range is a function of the measured Doppler shift.

[0182] Aspect 6 is a method according to aspect 3, wherein the Doppler shift range is a function of the speed of the UE.

[0183] Aspect 7 is a method according to aspect 3, wherein the Doppler shift range is a function of the environment of the UE.

[0184] Aspect 8 is a method according to any one of Aspects 1 to 7, wherein the de-weighting or exclusion of one or more signals in the received signals when estimating the positioning of the UE based on whether the corresponding received signal is determined to be a multipath signal includes: when the corresponding signal is determined to be a multipath signal, excluding each of the one or more signals in the received signals when estimating the positioning of the UE.

[0185] Aspect 9 is a method according to any one of Aspects 1 to 8, wherein the de-weighting or exclusion of one or more of the received signals when estimating the positioning of the UE based on whether the corresponding received signal is determined to be a multipath signal includes: when the corresponding signal is determined to be a multipath signal, when estimating the positioning of the UE, the measurement of each of the one or more signals in the received signal is de-weighted using W, where 0≤W<1.

[0186] Aspect 10 is a method according to aspect 9, wherein W is based on a difference between the measured Doppler shift and a threshold Doppler shift.

[0187] Aspect 11 is a method according to Aspect 9, wherein the first number N is equal to the number of the one or more entities, the second number M is equal to the number of transmitters of the one or more entities from which the signals determined to be multipath are received, and W is based on a comparison of the first number N and the second number M.

[0188] Aspect 12 is a method according to any one of aspects 1 to 11, the method also comprising sending measurement information or UE positioning estimates associated with the de-weighted or excluded one or more signals to at least one location server via a transmitter.

[0189] Aspect 13 is a method according to aspect 12, the method further comprising sending information indicating whether the measurement information or the UE positioning estimate is associated with one or more multipath signals to the at least one location server.

[0190] Aspect 14 is a method according to any one of aspects 1 to 13, wherein the multipath signal comprises a non-line-of-sight signal.

[0191] Aspect 15 is a method according to any one of Aspects 1 to 14, wherein the one or more entities include one or more satellites, one or more base stations, or a combination thereof.

[0192] Aspect 16 is a device for positioning estimation, wherein the device is used to implement any one of aspects 1 to 15.

[0193] Aspect 17 is a device for positioning estimation, comprising means for implementing any one of aspects 1 to 15.

[0194] Aspect 18 is a computer-readable medium storing computer-executable code, wherein the code, when executed by a processor, causes the processor to implement any one of aspects 1 to 15.

[0195] Aspect 19 is a method for positioning at a UE, the method comprising: receiving signals from one or more entities via a receiver; determining whether each received signal is a multipath signal based on Doppler frequency shift measurement; and sending measurement information associated with one or more of the received signals via a transmitter, the measurement information at least partially indicating whether each of the one or more signals is a multipath signal.

[0196] Aspect 20 is a method according to Aspect 19, wherein determining whether each received signal is a multipath signal based on the Doppler frequency shift measurement includes: measuring the Doppler frequency shift of the received signal; and determining whether the residual of the measured Doppler frequency shift of the received signal exceeds a threshold Doppler frequency shift, wherein when the residual of the measured Doppler frequency shift of the received signal exceeds the threshold Doppler frequency shift, the received signal is determined to be a multipath signal.

[0197] Aspect 21 is a method according to aspect 20, wherein the threshold Doppler shift is equal to the expected Doppler shift plus or minus a Doppler shift range.

[0198] Aspect 22 is a method according to aspect 21, wherein the Doppler shift range is one of: a constant value; a function of the measured Doppler shift; a function of the residual of the measured Doppler shift; a function of the speed of the UE; or a function of the environment of the UE.

[0199] Aspect 23 is a method according to any one of aspects 19 to 22, wherein the measurement information further indicates the Doppler shift measurement of the one or more signals.

[0200] Aspect 24 is a method according to any one of aspects 19 to 23, wherein the measurement information is sent to a location server.

[0201] Aspect 25 is a method according to any one of aspects 19 to 24, wherein the multipath signal comprises a non-line-of-sight signal.

[0202] Aspect 26 is a method according to any one of Aspects 19 to 25, wherein the one or more entities include one or more satellites, one or more base stations, or a combination thereof.

[0203] Aspect 27 is a device for positioning estimation, wherein the device is used to implement any one of aspects 19 to 26.

[0204] Aspect 28 is an apparatus for positioning estimation, comprising means for implementing any one of aspects 19 to 26.

[0205] Aspect 29 is a computer-readable medium storing computer-executable code, wherein the code, when executed by a processor, causes the processor to implement any one of aspects 19 to 26.

Claims

1. An apparatus for performing positioning at a user equipment (UE), the apparatus comprising: Memory; Receiver; and at least one processor, the at least one processor coupled to the memory and the receiver, the at least one processor configured to: receiving, via the receiver, a signal from one or more entities; determining whether each received signal is a multipath signal based on the Doppler shift measurement; as well as One or more of the received signals are de-weighted or excluded when estimating the location of the UE based on whether the corresponding received signal is determined to be a multipath signal.

2. The apparatus of claim 1 , wherein to determine whether each received signal is a multipath signal based on the Doppler shift measurement, the at least one processor is further configured to: measuring the Doppler shift of the received signal; and determining whether a residual of the measured Doppler shift frequency of the received signal exceeds a threshold Doppler shift frequency, Wherein when the residual of the measured Doppler shift of the received signal exceeds the threshold Doppler shift, the received signal is determined to be a multipath signal.

3. The apparatus of claim 2, wherein the threshold Doppler shift is equal to an expected Doppler shift plus or minus a Doppler shift range.

4. The apparatus of claim 3, wherein the Doppler shift range is one of: Constant value, A function of the measured Doppler shift, A function of the residual of the measured Doppler shift, a function of the speed of the UE, or A function of the environment of the UE.

5. The apparatus of claim 1 , wherein in order to de-weight or exclude one or more of the received signals when estimating the positioning of the UE based on whether the corresponding received signal is determined to be a multipath signal, the at least one processor is further configured to: When the corresponding signal is determined to be a multipath signal, each of the one or more signals in the received signals is excluded when estimating the position of the UE.

6. The apparatus of claim 1 , wherein in order to de-weight or exclude one or more of the received signals when estimating the positioning of the UE based on whether the corresponding received signal is determined to be a multipath signal, the at least one processor is further configured to: When the corresponding signal is determined to be a multipath signal, the measurement of each of the one or more signals in the received signals is de-weighted by W when estimating the positioning of the UE, where 0≤W<1.

7. The apparatus of claim 6, wherein W is based on a difference between the measured Doppler shift and a threshold Doppler shift.

8. The apparatus of claim 6, wherein a first number N is equal to the number of the one or more entities, a second number M is equal to the number of transmitters of the one or more entities from which signals determined to be multipath are received, and W is based on a comparison of the first number N and the second number M.

9. The apparatus according to claim 1 further comprises a transmitter, wherein the at least one processor is further configured to send measurement information or UE positioning estimates associated with the de-weighted or excluded one or more signals to at least one location server via the transmitter.

10. The apparatus of claim 9, wherein the at least one processor is further configured to send information to the at least one location server indicating whether the measurement information or the UE position estimate is associated with one or more multipath signals.

11. The apparatus of claim 1, wherein the multipath signal comprises a non-line-of-sight (NLOS) signal.

12. The apparatus of claim 1, wherein the one or more entities comprise one or more satellites, one or more base stations, or a combination thereof.

13. A method for positioning at a user equipment (UE), the method comprising: receiving, via a receiver, a signal from one or more entities; determining whether each received signal is a multipath signal based on the Doppler shift measurement; as well as One or more of the received signals are de-weighted or excluded when estimating the location of the UE based on whether the corresponding received signal is determined to be a multipath signal.

14. The method of claim 13, wherein the determining whether each received signal is a multipath signal based on the Doppler shift measurement comprises: measuring the Doppler shift of the received signal; as well as determining whether a residual of the measured Doppler shift frequency of the received signal exceeds a threshold Doppler shift frequency, Wherein when the residual of the measured Doppler shift of the received signal exceeds the threshold Doppler shift, the received signal is determined to be a multipath signal.

15. The method of claim 14, wherein the threshold Doppler shift is equal to an expected Doppler shift plus or minus a Doppler shift range.

16. The method of claim 15, wherein the Doppler shift range is one of: Constant value, A function of the measured Doppler shift, A function of the residual of the measured Doppler shift, a function of the speed of the UE, or A function of the environment of the UE.

17. The method of claim 13, wherein the de-weighting or the excluding of one or more of the received signals when estimating the positioning of the UE based on whether the corresponding received signals are determined to be multipath signals comprises: When the corresponding signal is determined to be a multipath signal, each of the one or more signals in the received signals is excluded when estimating the position of the UE.

18. The method of claim 13, wherein the de-weighting or the excluding of one or more of the received signals when estimating the positioning of the UE based on whether the corresponding received signals are determined to be multipath signals comprises: When the corresponding signal is determined to be a multipath signal, the measurement of each of the one or more signals in the received signals is de-weighted by W when estimating the positioning of the UE, where 0≤W<1.

19. The method according to claim 13, further comprising: transmitting, via a transmitter, measurement information or a UE positioning estimate associated with the de-weighted or the excluded one or more signals to at least one location server; as well as Information indicating whether the measurement information or the UE position estimate is associated with one or more multipath signals is sent to the at least one location server.

20. An apparatus for performing positioning at a user equipment (UE), the apparatus comprising: Memory; Receiver; Transmitter; and at least one processor, the at least one processor coupled to the memory, the receiver, and the transmitter, the at least one processor configured to: receiving, via the receiver, a signal from one or more entities; determining whether each received signal is a multipath signal based on the Doppler shift measurement; as well as Measurement information associated with one or more of the received signals is transmitted via the transmitter, the measurement information indicating, at least in part, whether each of the one or more signals is a multipath signal.

21. The apparatus of claim 20, wherein to determine whether each received signal is a multipath signal based on the Doppler shift measurement, the at least one processor is further configured to: measuring the Doppler shift of the received signal; and determining whether a residual of the measured Doppler shift frequency of the received signal exceeds a threshold Doppler shift frequency, Wherein when the residual of the measured Doppler shift of the received signal exceeds the threshold Doppler shift, the received signal is determined to be a multipath signal.

22. The apparatus of claim 21, wherein the threshold Doppler shift is equal to an expected Doppler shift plus or minus a Doppler shift range.

23. The apparatus of claim 22, wherein the Doppler shift range is one of: Constant value; function of the measured Doppler shift; A function of the residual of the measured Doppler shift, a function of the speed of the UE; or A function of the environment of the UE.

24. The apparatus of claim 20, wherein the measurement information further indicates the Doppler shift measurement of the one or more signals.

25. The apparatus of claim 20, wherein the measurement information is sent to a location server.

26. The apparatus of claim 20, wherein the multipath signal comprises a non-line-of-sight (NLOS) signal.

27. The apparatus of claim 20, wherein the one or more entities comprise one or more satellites, one or more base stations, or a combination thereof.

28. A method for positioning at a user equipment (UE), the method comprising: receiving, via a receiver, a signal from one or more entities; determining whether each received signal is a multipath signal based on the Doppler shift measurement; as well as Measurement information associated with one or more of the received signals is transmitted via a transmitter, the measurement information indicating, at least in part, whether each of the one or more signals is a multipath signal.

29. The method of claim 28, wherein determining whether each received signal is a multipath signal based on the Doppler shift measurement comprises: measuring the Doppler shift of the received signal; as well as determining whether a residual of the measured Doppler shift frequency of the received signal exceeds a threshold Doppler shift frequency, Wherein when the residual of the measured Doppler shift of the received signal exceeds the threshold Doppler shift, the received signal is determined to be a multipath signal.

30. The method of claim 29, wherein the threshold Doppler shift is equal to an expected Doppler shift plus or minus a Doppler shift range, and wherein the Doppler shift range is one of: Constant value; function of the measured Doppler shift; A function of the residual of the measured Doppler shift, a function of the speed of the UE; or A function of the environment of the UE.

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