Configurable Reference Signal Timing Difference measurement (RSTD) search window

Abstract

A method and apparatus for providing a configurable reference signal timing difference (RSTD) search window for positioning is disclosed. In one aspect, the RSTD search window is configured based on a positioning reference signal (PRS) configuration (1310). The RSTD search window is provided to a UE (1320). Multiple PRSs are sent from a network entity to a user equipment (UE), each PRS having a PRS configuration. The multiple PRSs are sent in a subset of less than all subcarriers on a given bandwidth (1330).

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority under 35 U.S.C. §119 to Greek Patent Application No. 20190100022, filed on January 11, 2019, entitled “CONFIGURABLE REFERENCE SIGNAL TIME DIFFERENCE MEASUREMENT (RSTD) SEARCH WINDOW,” and U.S. Provisional Application No. 62 / 914,236, filed on October 11, 2019, entitled “CONFIGURABLE REFERENCE SIGNAL TIME DIFFERENCE MEASUREMENT (RSTD) SEARCH WINDOW,” and U.S. Non-Provisional Patent Application No. 16 / 739,067, filed on January 9, 2020, entitled “CONFIGURABLE REFERENCE SIGNAL TIME DIFFERENCE MEASUREMENT (RSTD) SEARCH WINDOW,” each of which is assigned to the present assignee and expressly incorporated herein by reference in its entirety. Technical Field

[0003] Various aspects described herein relate generally to wireless communication systems, and more particularly to a configurable reference signal timing difference (RSTD) search window for observed time difference of arrival (OTDOA) and multiple round trip times (RTT) based positioning. Background Art

[0004] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, data, multimedia, etc. A typical wireless communication system is a multiple access system capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple access systems 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, etc. These systems are typically deployed in accordance with the following specifications: Long Term Evolution (LTE) and Advanced LTE (LTE-A) provided by the Third Generation Partnership Project (3GPP), Ultra Mobile Broadband (UMB) and Evolution Data Optimized (EV-DO) provided by the Third Generation Partnership Project 2 (3GPP2), WiFi (also known as Wi-Fi) 802.11 provided by the Institute of Electrical and Electronics Engineers (IEEE), etc.

[0005] The fifth generation of mobile standards, known as "5G" or "New Radio" (NR), will enable, among other improvements, higher data speeds, a greater number of connections, and better coverage. The 5G standard according to the Next Generation Mobile Network Alliance aims to provide data rates of tens of megabits per second for each of tens of thousands of users and 1 gigabit per second for dozens of workers on an office floor. To support large sensor deployments, hundreds of thousands of simultaneous connections should be supported. As a result, the spectral efficiency of 5G mobile communications should be significantly enhanced compared to the current LTE standard. In addition, signaling efficiency should be enhanced and latency should be significantly reduced compared to current standards.

[0006] To support position estimation in terrestrial wireless networks, a mobile device may be configured to measure and report OTDOA or RSTD between reference RF signals received from two or more network nodes (e.g., different base stations or different transmission points (e.g., antennas) belonging to the same base station). Summary of the invention

[0007] A brief summary of one or more aspects disclosed herein is presented below. Therefore, the following summary should not be considered as a broad summary of all expected aspects, nor should the following summary be considered as identifying key or important elements related to all expected aspects or describing the scope associated with any particular aspect. Therefore, the sole purpose of the following summary is to present certain concepts about one or more aspects related to the mechanisms disclosed herein in a simplified form before the detailed description given below.

[0008] In one aspect, a method of operating a network entity includes: determining a reference signal timing difference (RSTD) search window based on a positioning reference signal (PRS) configuration; providing the RSTD search window to a user equipment (UE); and sending a plurality of PRSs to the UE, each PRS having a PRS configuration, wherein the plurality of PRSs are sent in a subset that is less than all subcarriers over a given bandwidth.

[0009] In one aspect, a network entity includes: a transceiver circuit; a memory circuit; and a processor circuit, wherein the transceiver circuit, the memory circuit, and the processor circuit are configured to: configure an RSTD search window based on a PRS configuration; provide the RSTD search window to a UE; and send a plurality of PRSs to the UE, each PRS having a PRS configuration, wherein the plurality of PRSs are sent in a subset of less than all subcarriers over a given bandwidth.

[0010] In one aspect, a network entity includes: a component for configuring an RSTD search window based on a PRS configuration; a component for providing the RSTD search window to a UE; and a component for sending a plurality of PRSs to the UE, each PRS having a PRS configuration, wherein the plurality of PRSs are sent in a subset of less than all subcarriers over a given bandwidth.

[0011] In one aspect, a non-transitory computer-readable medium storing computer-executable instructions for a network entity includes computer-executable instructions, the computer-executable instructions including: one or more instructions instructing the network entity to configure an RSTD search window based on a PRS configuration; one or more instructions instructing the network entity to provide the RSTD search window to a UE; and one or more instructions instructing the network entity to send a plurality of PRSs to the UE, each PRS having a PRS configuration, wherein the plurality of PRSs are sent in a subset that is less than all subcarriers over a given bandwidth.

[0012] In one aspect, a method of operating a UE includes: receiving an RSTD search window based on a PRS configuration; receiving multiple PRSs from a network node, each PRS having a PRS configuration, wherein the multiple PRSs are transmitted in a subset that is less than all subcarriers on a given bandwidth; and determining an RSTD between the network node and a reference node based on the RSTD search window.

[0013] In one aspect, a UE comprises: a transceiver circuit; a memory circuit; and a processor circuit, wherein the transceiver circuit, the memory circuit, and the processor circuit are configured to: receive an RSTD search window based on a PRS configuration; receive multiple PRSs from a network node, each PRS having a PRS configuration, wherein the multiple PRSs are sent in a subset that is less than all subcarriers on a given bandwidth; and determine the RSTD between the network node and a reference node based on the RSTD search window.

[0014] In one aspect, a UE includes: a component for receiving an RSTD search window based on a PRS configuration; a component for receiving multiple PRSs from a network node, each PRS having a PRS configuration, wherein the multiple PRSs are sent in a subset that is less than all subcarriers on a given bandwidth; and a component for determining the RSTD between the network node and a reference node based on the RSTD search window.

[0015] In one aspect, a non-transitory computer-readable medium storing computer-executable instructions for a UE includes computer-executable instructions, which include: one or more instructions instructing the UE to receive an RSTD search window based on a PRS configuration; one or more instructions instructing the UE to receive multiple PRSs from a network node, each PRS having a PRS configuration, wherein the multiple PRSs are sent in a subset that is less than all subcarriers on a given bandwidth; and one or more instructions instructing the UE to determine the RSTD between the network node and a reference node based on the RSTD search window.

[0016] In one aspect, a method of operating a location server includes: determining an RSTD search window based on a PRS configuration; providing the RSTD search window to a UE or a base station serving the UE; and configuring multiple PRSs to be sent to the UE, each PRS having a PRS configuration, wherein the multiple PRSs are sent in a subset that is less than all subcarriers on a given bandwidth.

[0017] In one aspect, a location server comprises: a transceiver circuit; a memory circuit; and a processor circuit, wherein the transceiver circuit, the memory circuit, and the processor circuit are configured to: determine an RSTD search window based on a PRS configuration; provide the RSTD search window to a UE or a base station serving the UE; and configure multiple PRSs to be sent to the UE, each PRS having a PRS configuration, wherein the multiple PRSs are sent in a subset that is smaller than all subcarriers on a given bandwidth.

[0018] In one aspect, a location server includes: a component for determining an RSTD search window based on a PRS configuration; a component for providing the RSTD search window to a UE or a base station serving the UE; and a component for configuring multiple PRSs to be sent to the UE, each PRS having a PRS configuration, wherein the multiple PRSs are sent in a subset that is less than all subcarriers on a given bandwidth.

[0019] In one aspect, a non-transitory computer-readable medium storing computer-executable instructions for a location server includes computer-executable instructions, which include: one or more instructions instructing the location server to determine an RSTD search window based on a PRS configuration; one or more instructions instructing the location server to provide the RSTD search window to a UE or a base station serving the UE; and one or more instructions instructing the location server to configure multiple PRSs to be sent to the UE, each PRS having a PRS configuration, wherein the multiple PRSs are sent in a subset that is less than all subcarriers on a given bandwidth.

[0020] Other objects and advantages associated with the various aspects disclosed herein will be apparent to those skilled in the art from the accompanying drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings are presented to aid in describing various aspects of the disclosure and are intended to be illustrative of these aspects only and not limiting thereof.

[0022] Figure 1 An exemplary wireless communication system in accordance with various aspects of the present disclosure is shown.

[0023] Figure 2A and Figure 2B Example wireless network structures in accordance with various aspects of the present disclosure are shown.

[0024] Figure 3 An example wireless communication system including a macro cell eNode B and a secondary cell eNode B in communication with a UE is illustrated in accordance with at least one aspect of the present disclosure.

[0025] Figure 4 is a diagram of the structure of an example LTE subframe sequence with PRS positioning opportunities.

[0026] Figure 5 and Figure 6 is a diagram illustrating further aspects of PRS transmission for cells supported by a wireless node.

[0027] Figure 7 is a diagram illustrating an example technique for determining the location of a mobile device using information obtained from multiple base stations.

[0028] Fig. 8A and Figure 8B A performance comparison between non-subsampled subcarriers and subsampled subcarriers for a given bandwidth is shown.

[0029] Fig. 9 is a graph illustrating channel energy response (CER) and potential aliasing issues for sub-sampled sub-carriers of a given bandwidth in accordance with at least one aspect of the present disclosure.

[0030] Fig.10 Defining an RSTD search window with respect to a substitute base station instead of a serving base station in accordance with at least one aspect of the present disclosure is shown.

[0031] Fig.11 Examples of operating frequency bands for a wireless communication system according to one or more aspects are shown.

[0032] Fig.12 Examples of frequency overlap between operating bands in accordance with one or more aspects are shown.

[0033] Fig.13 A method of operating a network entity according to at least one aspect of the present disclosure is shown.

[0034] Fig.14 A method of operating a UE according to at least one aspect of the present disclosure is shown.

[0035] Fig.15 A method of operating a location server in accordance with at least one aspect of the present disclosure is shown.

[0036] Elements with the same number or the same label in different figures will be considered to correspond to each other. Elements with a common numerical label followed by different letter suffixes may correspond to different examples of a common element type. Thus, for example, Figure 1 The base stations 102A, 102B, 102C, and 102D in FIG. 1 are all specific examples of a base station, and when all examples 102A to 102D are applicable, they may be referred to as a base station 102 . DETAILED DESCRIPTION

[0037] Various aspects described herein relate generally to wireless communication systems, and more particularly to configurable RSTD search windows for OTDOA and RTT based positioning.

[0038] These and other aspects are disclosed in the following description and related drawings to illustrate specific examples related to the exemplary aspects. After reading this disclosure, alternative aspects will be apparent to those skilled in the relevant art and may be constructed and practiced without departing from the scope or spirit of the disclosure. In addition, in order not to obscure the relevant details of the various aspects described herein, well-known elements may not be described in detail or may be omitted.

[0039] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects. Likewise, the term "aspects" does not require that all aspects include the discussed feature, advantage, or mode of operation.

[0040] The terms used herein only describe specific aspects and should not be construed as limiting any aspect disclosed herein. As used herein, unless the context clearly indicates otherwise, the singular forms "one", "one" and "described / the" are intended to also include plural forms. It will be further understood by those skilled in the art that the terms "include", "include", "include" and / or "include" used herein specify the presence of the features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof. In addition, many aspects are described according to the sequence of actions to be performed by the elements of, for example, computing devices. It will be appreciated that the various actions described herein can be performed by a specific circuit (for example, an application specific integrated circuit (ASIC)), by a program instruction executed by one or more processors, or by a combination of the two. In addition, for each aspect described herein, the corresponding form of any such aspect can be implemented as, for example, "configured to" perform the described action "logic" in this article.

[0041] As used herein, the terms "user equipment" ("UE") and "base station" are not intended to be dedicated to or otherwise limited to any particular radio access technology (RAT), unless otherwise specified. In general, a UE may be any wireless communication device (e.g., a mobile phone, a router, a tablet computer, a laptop computer, a tracking device, a wearable device (e.g., a smart watch, glasses, an augmented display (AR) / virtual display (VR) viewer, etc.), a vehicle (e.g., a car, a motorcycle, a bicycle, etc.), an Internet of Things (IoT) device, etc.) used by a user to communicate on a wireless communication network. The UE may be mobile or may be (e.g., at certain times) stationary and may communicate with a radio access network (RAN). As used herein, the term "UE" may be interchangeably referred to as an "access terminal" or "AT", "client device", "wireless device", "subscriber equipment", "subscriber terminal", "subscriber station", "user terminal" or "UT", "mobile terminal", "mobile station" or variations thereof. Typically, a UE may communicate with a core network via a RAN, and through the core network, the UE may be connected to external networks such as the Internet and to other UEs. Of course, other mechanisms for the UE to connect to the core network and / or the Internet are also possible, such as through a wired access network, a wireless local area network (WLAN) network (eg, based on IEEE 802.11, etc.), and the like.

[0042] A base station may operate according to one of several RATs for communicating with a UE, depending on the network in which it is deployed, and may alternatively be referred to as an access point (AP), a network node, a NodeB, an evolved NodeB (eNB), an NR NodeB (also referred to as a gNB or gNodeB), etc. In addition, in some systems, a base station may provide pure edge node signaling functionality, while in other systems it may provide additional control and / or network management functionality. The communication link through which a UE may send a signal to a base station is referred to as an uplink (UL) channel (e.g., a reverse traffic channel, a reverse control channel, an access channel, etc.). The communication link through which a base station may send a signal to a UE is referred to as a downlink (DL) or forward link channel (e.g., a paging channel, a control channel, a broadcast channel, a forward traffic channel, etc.). As used herein, the term traffic channel (TCH) may refer to a UL / reverse or DL / forward traffic channel.

[0043] The term "base station" may refer to a single physical transmit receive point (TRP) or multiple physical TRPs, which may or may not be co-located. For example, when the term "base station" refers to a single physical TRP, the physical TRP may be an antenna of the base station corresponding to the cell of the base station. In the case where the term "base station" refers to multiple co-located physical TRPs, the physical TRP may be an antenna array of the base station (for example, as in a multiple-input multiple-output (MIMO) system or in the case where the base station adopts beamforming). In the case where the term "base station" refers to multiple non-co-located physical TRPs, the physical TRP may be a distributed antenna system (DAS) (a network of spatially separated antennas connected to a common source via a transmission medium) or a remote radio head (RRH) (a remote base station connected to a serving base station). Alternatively, a non-co-located physical TRP may be a serving base station that receives measurement reports from a UE and a neighboring base station whose reference RF signal the UE is measuring. Because a TRP is a point from which a base station sends and receives wireless signals, as used herein, references to sending from a base station or receiving at a base station will be understood to refer to a specific TRP of a base station.

[0044] An "RF signal" includes an electromagnetic wave of a given frequency that transmits information through the space between a transmitter and a receiver. As used herein, a transmitter may transmit a single "RF signal" or multiple "RF signals" to a receiver. However, due to the propagation characteristics of RF signals through multipath channels, a receiver may receive multiple "RF signals" corresponding to each transmitted RF signal. The same transmitted RF signal on different paths between a transmitter and a receiver may be referred to as a "multipath" RF signal.

[0045] Figure 1An exemplary wireless communication system 100 is shown. The wireless communication system 100 (which may also be referred to as a wireless wide area network (WWAN)) may include various base stations 102 and various UEs 104. The base stations 102 may include macro cells (high-power cellular base stations) and / or small cell base stations (low-power cellular base stations). In one aspect, the macro cell base stations may include eNBs (where the wireless communication system 100 corresponds to an LTE network), gNBs (where the wireless communication system 100 corresponds to an NR network), or a combination thereof, while the small cell base stations may include femto cells, pico cells, micro cells, etc.

[0046] The base stations 102 may collectively form a RAN and interface with a core network 170 (e.g., an evolved packet core (EPC) or a next generation core (NGC)) via a backhaul link 122 and to one or more location servers 172 via the core network 170. The base stations 102 may perform, among other functions, functions related to one or more of: transmitting user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS), subscriber and device tracking, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations 102 may communicate with each other directly or indirectly (e.g., via EPC / NGC) via a backhaul link 134, which may be wired or wireless.

[0047] Base stations 102 can communicate wirelessly with UEs 104. Each base station 102 can provide communication coverage for a respective geographic coverage area 110. In one aspect, one or more cells can be supported by base stations 102 in each coverage area 110. A "cell" is a logical communication entity used to communicate with a base station (e.g., through a certain frequency resource, which is called a carrier frequency, component carrier, carrier, frequency band, etc.), and can be associated with an identifier (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID)) for distinguishing cells operating via the same or different carrier frequencies. In some cases, different cells can be configured according to different protocol types (e.g., machine type communication (MTC), narrowband Internet of Things (NB-IoT), enhanced mobile broadband (eMBB) or others), which can provide access for different types of UEs. Because a cell is supported by a specific base station, the term "cell" can refer to one or both of the logical communication entity and the base station that supports it, depending on the context. In some cases, the term "cell" can also refer to a geographic coverage area (e.g., a sector) of a base station, as long as the carrier frequency can be detected and used for communication within a certain portion of the geographic coverage area 110.

[0048] Although the geographic coverage areas 110 of adjacent macrocell base stations 102 may partially overlap (e.g., in a handover region), some geographic coverage areas 110 may be largely overlapped by a larger geographic coverage area 110. For example, a small cell base station 102' may have a coverage area 110' that largely overlaps with the coverage area 110 of one or more macrocell base stations 102. A network including small cell base stations and macrocell base stations may be referred to as a heterogeneous network. A heterogeneous network may also include a home eNB (HeNB), which may provide services to a restricted group referred to as a closed subscriber group (CSG).

[0049] The communication link 120 between the base station 102 and the UE 104 may include an uplink (UL) (also referred to as a reverse link) transmission from the UE 104 to the base station 102 and / or a downlink (DL) (also referred to as a forward link) transmission from the base station 102 to the UE 104. The communication link 120 may employ MIMO antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link 120 may be over one or more carrier frequencies. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL ​​than for UL).

[0050] The wireless communication system 100 may also include a wireless local area network (WLAN) access point (AP) 150 that communicates with a WLAN station (STA) 152 via a communication link 154 in an unlicensed spectrum (e.g., 5 GHz). When communicating in the unlicensed spectrum, the WLAN STA 152 and / or the WLAN AP 150 may perform a clear channel assessment (CCA) or a listen before talk (LBT) process prior to communication to determine whether the channel is available.

[0051] More specifically, LBT is a mechanism by which a transmitter (e.g., a UE on the uplink or a base station on the downlink) applies CCA before using a channel / subband. Thus, before transmission, the transmitter performs a CCA check and listens to the channel / subband for the duration of the CCA observation time, which should not be less than a certain threshold (e.g., 15 microseconds). If the energy level in the channel exceeds a certain threshold (proportional to the transmitter's transmit power), the channel can be considered occupied. If the channel is occupied, the transmitter should delay further attempts to access the medium by a random factor (e.g., a number between 1 and 20) multiplied by the CCA observation time. If the channel is not occupied, the transmitter can start transmitting. However, the maximum continuous transmission time on the channel should be less than a certain threshold, such as 5 milliseconds.

[0052] The small cell base station 102' can operate in a licensed and / or unlicensed spectrum. When operating in an unlicensed spectrum, the small cell base station 102' can adopt LTE or NR technology and use the same 5GHz unlicensed spectrum used by the WLAN AP150. The small cell base station 102' adopting LTE / 5G in the unlicensed spectrum can enhance the coverage of the access network and / or increase the capacity of the access network. NR in the unlicensed spectrum can be referred to as NR-U. LTE in the unlicensed spectrum can be referred to as LTE-U, License Assisted Access (LAA) or MulteFire.

[0053] The wireless communication system 100 may also include a millimeter wave (mmW) base station 180, which can operate at mmW frequencies and / or near mmW frequencies to communicate with UE 182. Extremely high frequency (EHF) is part of RF in the electromagnetic spectrum. The range of EHF is 30GHz to 300GHz, and the wavelength is between 1 mm and 10 mm. The radio waves in this band can be called millimeter waves. Near mmW can range down to a frequency of 3GHz, while the wavelength is 100 mm. The range of the super high frequency (SHF) band between 3GHz and 30GHz is also called centimeter waves. Communication using mmW / near mmW radio frequency bands has high path loss and a relatively short range. The mmW base station 180 and the UE 182 can utilize beamforming (transmitting and / or receiving) on ​​the mmW communication link 184 to compensate for the extremely high path loss and short distance. In addition, it will be understood that in an alternative configuration, one or more base stations 102 may also use mmW or near mmW and beamforming to send. Therefore, it should be understood that the foregoing description is merely exemplary and should not be construed as limiting the various aspects disclosed herein.

[0054] Transmit beamforming is a technique for focusing an RF signal in a specific direction. Traditionally, when a network node (e.g., a base station) broadcasts an RF signal, it broadcasts the signal in all directions (omnidirectional). With transmit beamforming, the network node determines the location (relative to the transmitting network node) of a given target device (e.g., a UE) and projects a stronger downlink RF signal in that specific direction, thereby providing a faster (in terms of data rate) and stronger RF signal to the receiving device. In order to change the directionality of the RF signal when transmitting, the network node can control the phase and relative amplitude of the RF signal at each of the one or more transmitters that broadcast the RF signal. For example, the network node can use an array of antennas (called a "phased array" or "antenna array") that creates a beam of RF waves that can be "steered" to point in different directions without actually moving the antenna. Specifically, the RF current from the transmitter is fed to each antenna in the correct phase relationship so that the radio waves from different antennas can be superimposed to increase the radiation in the desired direction, while canceling to suppress the radiation in the undesired direction.

[0055] The transmit beams can be quasi-co-located, which means that they appear to have the same parameters to the receiver (e.g., UE), regardless of whether the transmit antennas of the network nodes themselves are actually co-located. In NR, there are four types of quasi-co-location (QCL) relationships. Specifically, a given type of QCL relationship means that certain parameters about the second reference RF signal on the second beam can be derived from information about the source reference RF signal on the source beam. Therefore, if the source reference RF signal is QCL type A, the receiver can use the source reference RF signal to estimate the Doppler shift, Doppler spread, average delay and delay spread of the second reference RF signal sent on the same channel. If the source reference RF signal is QCL type B, the receiver can use the source reference RF signal to estimate the Doppler shift and Doppler spread of the second reference RF signal sent on the same channel. If the source reference RF signal is QCL type C, the receiver can use the source reference RF signal to estimate the Doppler shift and average delay of the second reference RF signal sent on the same channel. If the source reference RF signal is QCL type D, the receiver can use the source reference RF signal to estimate the spatial reception parameters of the second reference RF signal sent on the same channel.

[0056] In receive beamforming, a receiver uses a receive beam to amplify an RF signal detected on a given channel. For example, a receiver may increase a gain setting and / or adjust a phase setting of an antenna array in a particular direction to amplify (e.g., increase its gain level) the RF signal received from that direction. Thus, when a receiver is said to be beamforming in a certain direction, this means that the beam gain in that direction is high relative to the beam gain along other directions, or that the beam gain in that direction is the highest compared to the beam gain in that direction of all other receive beams available to the receiver. This results in a stronger received signal strength (e.g., reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-interference-plus-noise ratio (SINR), etc.) for the RF signal received from that direction.

[0057] The receive beams may be spatially correlated. Spatial correlation means that the parameters of the transmit beam of the second reference signal may be derived from information about the receive beam of the first reference signal. For example, the UE may receive a reference downlink reference signal (e.g., a synchronization signal block (SSB)) from a base station using a specific receive beam. The UE may then form a transmit beam for transmitting an uplink reference signal (e.g., a sounding reference signal (SRS)) to the base station based on the parameters of the receive beam.

[0058] Note that a "downlink" beam can be either a transmit beam or a receive beam, depending on the entity that forms it. For example, if the base station is forming a downlink beam to send a reference signal to the UE, the downlink beam is a transmit beam. However, if the UE is forming a downlink beam, then it is the receive beam that receives the downlink reference signal. Similarly, an "uplink" beam can be either a transmit beam or a receive beam, depending on the entity that forms it. For example, if the base station is forming an uplink beam, then it is an uplink receive beam, and if the UE is forming an uplink beam, then it is an uplink transmit beam.

[0059] In 5G, the spectrum in which wireless nodes (e.g., base stations 102 / 180, UEs 102 / 180) operate is divided into multiple frequency ranges: FR1 (from 450 to 6000 MHz), FR2 (from 24250 to 52600 MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). In a multi-carrier system (such as 5G), one of the carrier frequencies is called the "primary carrier" or "anchor carrier" or "primary serving cell" or "PCell", and the remaining carrier frequencies are called "secondary carriers" or "secondary serving cells" or "SCells". In carrier aggregation, the anchor carrier is a carrier operating on the primary frequency (e.g., FR1) employed by the UE 102 / 180 and the cell in which the UE 102 / 180 performs an initial radio resource control (RRC) connection establishment procedure or initiates an RRC connection reestablishment procedure. The primary carrier carries all common and UE-specific control channels and can be a carrier in a licensed frequency (however, this is not always the case). A secondary carrier is a carrier operating on a second frequency (e.g., FR2) that can be configured once an RRC connection is established between the UE 104 and the anchor carrier, and can be used to provide additional radio resources. In some cases, the secondary carrier may be a carrier in an unlicensed frequency. The secondary carrier may contain only necessary signaling information and signals, for example, UE-specific signaling information and signals may not be present in the secondary carrier, because the primary uplink and downlink carriers are typically UE-specific. This means that different UEs 102 / 180 in a cell may have different downlink primary carriers. The same is true for the uplink primary carrier. The network is able to change the primary carrier of any UE 102 / 180 at any time. For example, this is done to balance the load on different carriers. Because a "serving cell" (whether a PCell or an SCell) corresponds to a carrier frequency / component carrier through which a base station is communicating, the terms "cell", "serving cell", "component carrier", "carrier frequency", etc. can be used interchangeably.

[0060] For example, still refer to Figure 1 , one of the frequencies used by the macrocell base station 102 may be an anchor carrier (or "PCell"), and the other frequencies used by the macrocell base station 102 and / or the mmW base station 180 may be secondary carriers ("SCells"). Simultaneous transmission and / or reception of multiple carriers enables the UE 102 / 180 to significantly increase its data transmission and / or reception rate. For example, two 20 MHz aggregated carriers in a multi-carrier system will theoretically achieve a data rate that is twice as high (i.e., 40 MHz) as that achieved by a single 20 MHz carrier.

[0061] The wireless communication system 100 may also include one or more UEs, such as UE 190, that are indirectly connected to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links. Figure 1 In the example of FIG. 1 , UE 190 has a D2D P2P link 192 with one of UEs 104 connected to one of base stations 102 (e.g., through which UE 190 can indirectly obtain cellular connectivity), and also has a D2D P2P link 194 with WLAN STA 152 connected to WLAN AP 150 (through which UE 190 can indirectly obtain WLAN-based Internet connectivity). In one example, any well-known D2DRAT (such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), Bluetooth etc.) to support D2D P2P links 192 and 194.

[0062] The wireless communication system 100 may also include a UE 164, which may communicate with the macrocell base station 102 via a communication link 120 and / or communicate with the mmW base station 180 via a mmW communication link 184. For example, the macrocell base station 102 may support a PCell and one or more SCells for the UE 164, and the mmW base station 180 may support one or more SCells for the UE 164.

[0063] According to various aspects, Figure 2AAn example wireless network architecture 200 is shown. For example, the NGC 210 (also referred to as "5GC") can be functionally viewed as a control plane function 214 (e.g., UE registration, authentication, network access, gateway selection, etc.) and a user plane function 212 (e.g., UE gateway function, access to data networks, IP routing, etc.), which operate in coordination to form a core network. The user plane interface (NG-U) 213 and the control plane interface (NG-C) 215 connect the gNB 222 to the NGC 210, and specifically to the control plane function 214 and the user plane function 212. In an additional configuration, the eNB 224 can also be connected to the NGC 210 via the NG-C 215 to the control plane function 214 and the NG-U 213 to the user plane function 212. In addition, the eNB 224 can communicate directly with the gNB 222 via the backhaul connection 223. In some configurations, the new RAN 220 may have only one or more gNBs 222, while other configurations include one or more of the eNBs 224 and the gNBs 222. The gNB 222 or the eNB 224 may communicate with the UE 204 (e.g., Figure 1 204). Another optional aspect may include a location server 230 that can communicate with the NGC 210 to provide location assistance for the UE 204. The location server 230 may be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules distributed across multiple physical servers, etc.), or alternatively may each correspond to a single server. The location server 230 may be configured to support one or more location services for the UE 204, which may be connected to the location server 230 via the core network, the NGC 210, and / or via the Internet (not shown). In addition, the location server 230 may be integrated into a component of the core network, or alternatively may be located external to the core network.

[0064] According to various aspects, Figure 2BAnother example wireless network structure 250 is shown. For example, the NGC 260 (also referred to as "5GC") can be functionally viewed as a control plane function (provided by the access and mobility management function (AMF) / user plane function (UPF) 264) and a user plane function (provided by the session management function (SMF) 262), which operate in coordination to form a core network (i.e., NGC 260). The user plane interface 263 and the control plane interface 265 connect the eNB 224 to the NGC 260, and specifically to the SMF 262 and the AMF / UPF 264, respectively. In an additional configuration, the gNB 222 may also be connected to the NGC 260 via a control plane interface 265 to the AMF / UPF 264 and a user plane interface 263 to the SMF 262. In addition, the eNB 224 can communicate directly with the gNB 222 via the backhaul connection 223, whether or not there is a gNB direct connection to the NGC 260. In some configurations, the new RAN 220 may have only one or more gNBs 222, while other configurations include one or more of the eNBs 224 and the gNBs 222. The gNB 222 or the eNB 224 may communicate with the UE 204 (e.g., Figure 1 The base station of the new RAN 220 communicates with the AMF side of the AMF / UPF 264 through the N2 interface, and communicates with the UPF side of the AMF / UPF 264 through the N3 interface.

[0065] The functions of AMF include registration management, connection management, reachability management, mobility management, lawful interception, transmission of session management (SM) messages between UE 204 and SMF 262, transparent proxy service for routing SM messages, access authentication and access authorization, transmission of short message service (SMS) messages between UE 204 and short message service function (SMSF) (not shown), and security anchor functionality (SEAF). AMF also interacts with authentication server function (AUSF) (not shown) and UE 204, and receives intermediate keys established because of UE 204 authentication process. In the case of authentication based on UMTS (Universal Mobile Telecommunications System) Subscriber Identity Module (USIM), AMF retrieves security materials from AUSF. The functionality of AMF also includes security context management (SCM). SCM receives keys from SEAF, which is used to derive keys specific to access networks. The functions of AMF also include location service management for regulatory services, transmission of location service messages between UE 204 and location management function (LMF) 270 and between new RAN 220 and LMF 270, allocation of Evolved Packet System (EPS) carried identifier for interworking with EPS, and notification of mobility events of UE 204. In addition, AMF also supports the functions of non-3GPP access networks.

[0066] The functions of the UPF include acting as an anchor point for intra-RAT / inter-RAT mobility (when applicable), acting as an external protocol data unit (PDU) session point for interconnection with a data network (not shown), providing packet routing and forwarding, packet inspection, user plane policy rule enforcement (e.g., gating, redirection, traffic steering), lawful interception (user plane collection), traffic usage reporting, user plane quality of service (QoS) processing (e.g., UL / DL rate enforcement, reflective QoS marking in DL), UL traffic verification (service data flow (SDF) to QoS flow mapping), transport level packet marking in UL and DL, DL packet buffering and DL data notification triggering, and sending and forwarding of one or more "end markers" to the source RAN node.

[0067] The functions of SMF 262 include session management, UE Internet Protocol (IP) address allocation and management, selection and control of user plane functions, configuring service steering at UPF to route services to the correct destination, partial control of policy enforcement and QoS, and downlink data notification. The interface through which SMF 262 communicates with the AMF side of AMF / UPF 264 is called the N11 interface.

[0068] Another optional aspect may include an LMF 270 that can communicate with the NGC 260 to provide location assistance for the UE 204. The LMF 270 can be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules distributed on multiple physical servers, etc.), or alternatively can each correspond to a single server. The LMF 270 can be configured to support one or more location services for the UE 204, which can be connected to the LMF 270 via the core network, the NGC 260, and / or via the Internet (not shown).

[0069] Figure 3 The system includes two base stations (macro cell base station 102A and small cell base station 102B (eg, Figure 1 An example wireless communication system for a dual-mode UE 104 communicating with a small cell base station 102' in a wireless communication system. The UE 104 and the base station 102 each typically include a wireless communication device (represented by communication devices 312, 352, and 362) for communicating with other network elements via at least one designated RAT. Depending on the designated RAT, the communication devices 312, 352, and 362 can be configured in different ways to send and encode signals (e.g., messages, indications, information, etc.), and conversely, to receive and decode signals (e.g., messages, indications, information, pilots, etc.). In some aspects, the communication devices 312, 352, and 362 can be implemented as a transceiver (a combination of transmitter and receiver circuits), or as separate transmitter and receiver circuits.

[0070] As used herein, a "transceiver" may include transmitter circuitry, receiver circuitry, or a combination thereof, but need not provide both transmit and receive functionality in all designs. For example, when full communication need not be provided, a low-functionality receiver circuit may be employed in some designs to reduce cost (e.g., a receiver chip or similar circuit that provides only low-level sniffing). In addition, as used herein, the term "co-locate" (e.g., a radio, access point, transceiver, etc.) may refer to one of a variety of arrangements. For example, components located in the same housing; components hosted by the same processor; components within a defined distance of each other; and / or components connected via an interface (e.g., an Ethernet switch) that meets any required latency requirements for inter-component communication (e.g., message passing).

[0071] The UE 104 and the base station 102 may also each generally include a communication controller (represented by communication controllers 314, 354, and 364) for controlling the operation (e.g., directing, modifying, enabling, disabling, etc.) of their respective communication devices 312, 352, and 362. The communication controllers 314, 354, and 364 may operate in accordance with or otherwise in conjunction with respective host system functionality (shown as processing systems 316, 356, and 366 and memory components 318, 358, and 368). In some aspects, the processing systems 316, 356, and 366 may be implemented as one or more processors, one or more processor cores, a digital signal processor (DSP), an ASIC, a field programmable gate array (FPGA), etc. In some designs, the communication controllers 314, 354, and 364 may be partially or fully subsumed into the respective host system functionality.

[0072] As will be described in greater detail herein, the communications controller 314 includes a positioning module 324 that can perform (or cause performance of) the UE operations described herein for determining the location of the UE 104. In one aspect, the positioning module 324 can be a software module that stores instructions that, when executed by the processing system 316, cause the UE 104 to perform the UE operations described herein. In another aspect, the positioning module 324 can be a circuit that is part of or coupled to the processing system 316 that performs the UE operations described herein. In yet another aspect, the positioning module 324 can be a combination of hardware and software, such as a firmware component of the UE 104 or a modem for the UE 104.

[0073] In addition, despite the Figure 3 104. Although not shown in the drawings, the base stations 102 can each include a positioning module that can perform or cause the base station operations described herein for determining the location of the UE 104. In one aspect, such a positioning module can be a software module that stores instructions that, when executed by the processing system 356 / 366, cause the base station 102 to perform the base station operations described herein. In another aspect, such a positioning module can be a circuit that is part of the processing system 356 / 366 or coupled to the processing system 356 / 366 that performs the base station operations described herein. In yet another aspect, such a positioning module can be a combination of hardware and software, such as a firmware component of the base station 102.

[0074] Turning to the communications shown in more detail, the UE 104 can send and / or receive messages with the macrocell base station 102A via a "primary" wireless link 342 in a licensed spectrum. The UE 104 can also send and / or receive messages with the small cell base station 102B via a "secondary" wireless link 344 in an unlicensed spectrum. Therefore, the small cell base station 102B can also be referred to as a secondary cell base station. Messages may include information related to various types of communications (e.g., voice, data, multimedia services, related control signaling, etc.). In general, the macrocell base station 102A can operate in accordance with a licensed RAT (e.g., LTE or 5G) via the primary wireless link 342. The small cell base station 102B can operate in accordance with an unlicensed RAT (e.g., LTE-Unlicensed TM 、MulteFire TM , WiFi TM , 5G in unlicensed spectrum, etc.) via a secondary wireless link 344. The secondary wireless link 344 may operate over a public wireless communication medium of interest, which is Figure 3 340, which may be shared with other communication systems and signaling schemes. This type of medium may be composed of one or more frequency, time, and / or space communication resources (e.g., including one or more channels across one or more carriers) associated with communication between one or more transmitter / receiver pairs.

[0075] As a specific example, the wireless communication medium 340 may correspond to at least a portion of an unlicensed frequency band shared among various RATs. Although different licensed frequency bands have been reserved for certain communication systems (e.g., by government entities such as the Federal Communications Commission (FCC) in the United States), these systems (particularly systems employing small cell access points) have recently expanded operations to unlicensed frequency bands (such as the U-NII band used by WLAN technologies, most notably IEEE 802.11x WLAN technologies (commonly referred to as "WiFi" or "Wi-Fi"). Examples of such systems include different variations of CDMA systems, TDMA systems, FDMA systems, OFDMA systems, SC-FDMA systems, and the like.

[0076] exist Figure 3In the example of , the communication device 312 of the UE 104 includes a licensed RAT transceiver 320 configured to operate according to the licensed RAT of the macrocell base station 102A and a co-located unlicensed RAT transceiver 322 configured to operate according to the unlicensed RAT of the small cell base station 102B. As an example, the licensed RAT transceiver 320 can operate according to LTE or 5G technology, while the unlicensed RAT transceiver 322 can operate according to LTE in unlicensed frequencies, 5G in unlicensed spectrum, or WiFi technology. In some implementations, the licensed RAT transceiver 320 and the unlicensed RAT transceiver 322 can include the same transceiver.

[0077] Referring to processing systems 356 and 366 in more detail, in the downlink, IP packets from network entities (e.g., location server 230, LMF 270) may be provided to processing systems 356 / 366. Processing systems 356 / 366 may implement functionality for the RRC layer, the Packet Data Convergence Protocol (PDCP) layer, the Radio Link Control (RLC) layer, and the Medium Access Control (MAC) layer. The processing system 356 / 366 can provide RRC layer functionality associated with broadcasting of system information (e.g., master information block (MIB), system information block (SIB)), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-RAT mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and switching support functions; RLC layer functionality associated with transmission of upper layer packet data units (PDUs), error correction through automatic repeat request (ARQ), concatenation, segmentation and reassembly of RLC service data units (SDUs), resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, scheduling information reporting, error correction, priority handling, and logical channel priority.

[0078] The communication device 352 / 362 can implement layer 1 functionality associated with various signal processing functions. Layer 1, including the physical (PHY) layer, can include error detection on the transmission channel, forward error correction (FEC) encoding / decoding of the transmission channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The transmitter (not shown) of the communication device 352 / 362 processes the mapping to the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols can then be divided into parallel streams. Each stream can then be mapped to an orthogonal frequency multiplexing (OFDM) subcarrier, multiplexed with a reference signal (e.g., a pilot) in the time domain and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to generate multiple spatial streams. The channel estimate from the channel estimator can be used to determine the coding and modulation scheme and for spatial processing. The channel estimate can be derived from a reference signal and / or channel condition feedback sent by the UE 104. Each spatial stream can then be provided to one or more different antennas. The transmitter of the communication device 352 / 362 can modulate the RF carrier with the respective spatial stream for transmission.

[0079] At UE 104, transceiver 320 / 322 receives the signal through its respective antenna. Transceiver 320 / 322 recovers the information modulated onto the RF carrier and provides the information to processing system 316. Transceiver 320 / 322 implements layer 1 functionality associated with various signal processing functions. Transceiver 320 / 322 can perform spatial processing on the information to recover any spatial stream destined for UE 104. If multiple spatial streams are destined for UE 104, they can be combined into a single OFDM symbol stream by transceiver 320 / 322. Then, transceiver 320 / 322 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. By determining the most likely signal constellation point sent by base station 102, the symbol on each subcarrier and the reference signal are recovered and demodulated. These soft decisions can be based on channel estimates calculated by a channel estimator. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally sent on the physical channel by the base station 102. The data and control signals are then provided to a processing system 316 that implements layer 3 and layer 2 functionality.

[0080] In the UL, the processing system 316 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets from the core network. The processing system 316 is also responsible for error detection.

[0081] Similar to the functionality described in conjunction with the DL transmission performed by the base station 102, the processing system 316 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 transmission of upper layer PDUs, error correction through ARQ, splicing, 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 on transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0082] Channel estimates derived by the channel estimator from a reference signal or feedback sent by the base station 102 can be used by the transceiver 320 / 322 to select appropriate coding and modulation schemes and facilitate spatial processing. The spatial streams generated by the transceiver 320 / 322 can be provided to different antennas. The transceiver 320 / 322 can modulate the RF carrier with the respective spatial streams for transmission.

[0083] UL transmissions are processed at the base station 102 in a manner similar to that described in conjunction with the receiver functionality at the UE 104. A receiver (not shown) of the communication device 352 / 362 receives the signal through its respective antenna. The communication device 352 / 362 recovers the information modulated onto the RF carrier and provides the information to the processing system 356 / 366.

[0084] In the UL, the processing system 356 / 366 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover IP packets from the UE 104. The IP packets from the processing system 356 / 366 may be provided to the core network. The processing system 356 / 366 is also responsible for error detection.

[0085] The various components of UE 104 and base station 102 may communicate with each other via a data bus (not shown). Figure 3 The components of can be implemented in various ways. In some implementations, Figure 3The components of may be implemented in one or more circuits, for example, one or more processors and / or one or more ASICs (which may include one or more processors). Here, each circuit may use and / or incorporate at least one memory component for storing information or executable code used by the circuit to provide this functionality. For example, some or all of the functionality represented by blocks 312, 314, 316, 318, 320, 322, and 324 may be implemented by the processor and memory components of UE 104 (e.g., by executing appropriate code and / or by appropriate configuration of the processor components). Similarly, some or all of the functionality represented by blocks 352, 354, 356, and 358 may be implemented by the processor and memory components of base station 102A (e.g., by executing appropriate code and / or by appropriate configuration of the processor components). In addition, some or all of the functionality represented by blocks 362, 364, 366, and 368 may be implemented by the processor and memory components of base station 102B (e.g., by executing appropriate code and / or by appropriate configuration of the processor components). For simplicity, various operations, actions and / or functions are described herein as being performed “by a UE,” “by a base station,” “by a positioning entity,” etc. However, as will be appreciated, such operations, actions and / or functions may actually be performed by a specific component or combination of components of the UE, base station, positioning entity, etc., such as the processing systems 316, 356, and 366, the communication devices 312, 352, and 362, the communication controllers 314, 354, and 364, etc.

[0086] To support position estimation in terrestrial wireless networks, the UE 104 may be configured to measure and report OTDOA between reference RF signals received from two or more network nodes (e.g., different base stations 102 or different TRPs (e.g., antenna arrays) belonging to the same base station 102). Such reference signals may be referred to as positioning reference signaling (PRS) signals in LTE and as navigation reference signaling (NRS) signals in 5G. As used herein, the term "positioning reference signal" or PRS refers to LTE PRS, 5G NRS, or any other type of reference signal that may be used for positioning, such as a cell-specific reference signal (CRS), a tracking reference signal (TRS), a channel state information reference signal (CSI-RS), a primary synchronization signal (PSS), a secondary synchronization signal (SSS), etc.

[0087] As discussed further below, OTDOA is a positioning method for wireless networks that use NR to provide wireless access, and is also a multi-point positioning method. In this method, UE 104 measures the time differences (referred to as RSTD) between specific reference RF signals (e.g., PRS, CRS, CSI-RS, etc.) sent by different pairs of network nodes (e.g., base station 102, antenna of base station 102, etc.), and reports these time differences to a location server (such as location server 230, LMF 270) or calculates the position estimate based on these time differences.

[0088] Figure 4 The structure of an example subframe sequence 400 with PRS positioning opportunities is shown. The subframe sequence 400 may be suitable for broadcasting a PRS signal from a base station 102 in the communication system 100. Figure 4 An example of a subframe sequence for LTE is provided, however, similar or different subframe sequence implementations may be implemented for other communication technologies / protocols (such as NR). Figure 4 In FIG. 1 , time is represented horizontally (e.g., on the X-axis), where time increases from left to right, and frequency is represented vertically (e.g., on the Y-axis), where frequency increases (or decreases) from bottom to top. Figure 4 As shown, downlink and uplink radio frames 410 may each have a duration of 10 milliseconds (ms). For downlink frequency division duplex (FDD) mode, in the illustrated embodiment, radio frames 410 are organized into ten subframes 412, each having a duration of 1 ms. Each subframe 412 includes two time slots 414, each having a duration of, for example, 0.5 ms.

[0089] In the frequency domain, the available bandwidth can be divided into evenly spaced orthogonal subcarriers 416. For example, for a normal length cyclic prefix using, for example, 15 kHz spacing, the subcarriers 416 can be grouped into groups of twelve (12) subcarriers. Each grouping of 12 subcarriers 416 is called a resource block (RB), and in the above example, the number of subcarriers in a resource block can be written as For a given channel bandwidth, the number of available resource blocks on each channel 422 (which is also referred to as a transmission bandwidth configuration 422) is represented as For example, for the 3 MHz channel bandwidth in the above example, the number of available resource blocks on each channel 422 is given by Given.

[0090] exist Figure 1 In the communication system 100 shown, a base station 102 (such as a macro cell base station 102A or any one of small cell base stations 102B to 110D) can be configured according to the Figure 4and (described later) Figure 5 Frames or other physical layer signaling sequences supporting PRS signals (i.e., downlink (DL) PRS) may be transmitted in a similar or identical frame configuration to the frame configuration shown in , which may be measured and used for UE (e.g., UE 104) position determination. As noted, other types of wireless nodes and base stations (e.g., gNBs or WiFi APs) may also be configured to transmit frames to communicate with Figure 4 and Figure 5 A PRS signal configured in a manner similar to (or identical to) that described in Since the PRS transmission performed by a wireless node or base station is directed to all UEs within the radio range, it can also be considered that the wireless node or base station transmits (or broadcasts) the PRS.

[0091] The PRS may be sent by a wireless node (e.g., base station 102) after appropriate configuration (e.g., by an operations and maintenance (O&M) server). The PRS may be sent in a special positioning subframe that is grouped into multiple positioning opportunities. The PRS opportunities may be grouped into one or more PRS opportunity groups. For example, in LTE, a PRS positioning opportunity may include a number of N PRS consecutive positioning subframes, where the number is N PRS can be between 1 and 160 (e.g., can include values ​​1, 2, 4, and 6, among other values). PRS positioning opportunities for cells supported by a wireless node can be spaced at time intervals (numbered by T PRS milliseconds (or subframes) of time intervals) occur periodically, where T PRS can be equal to 5, 10, 20, 40, 80, 160, 320, 640, or 1280 (or any other suitable value). As an example, Figure 4 shows the periodicity of positioning opportunities, where N PRS 418 is equal to 4, and T PRS 420 is greater than or equal to 20. In some aspects, T PRS It may be measured as the number of subframes between the start of consecutive positioning opportunities.

[0092] As described herein, in some aspects, OTDOA assistance data may be provided to the UE 104 by the location server 230 or LMF 270 for a "reference cell" and one or more "neighboring cells" or "adjacent cells" relative to the "reference cell." For example, the assistance data may provide the center channel frequency of each cell, various PRS configuration parameters (e.g., N PRS , T PRS , muting sequence, frequency hopping sequence, PRS ID, PRS bandwidth), cell global ID, PRS signal characteristics associated with directional PRS, and / or other cell-related parameters applicable to OTDOA or some other location method.

[0093] By indicating a serving cell for the UE 104 in the OTDOA assistance data (eg, where a reference cell is indicated as the serving cell), PRS-based positioning by the UE 104 may be facilitated.

[0094] In some aspects, the OTDOA assistance data may also include "expected RSTD" parameters that provide the UE 104 with information about the RSTD value that the UE 104 expects to measure at the current position between the reference cell and each neighboring cell, as well as the uncertainty of the expected RSTD parameter. The expected RSTD and the associated uncertainty may define a search window for the UE 104 within which the UE 104 expects to measure the RSTD value. In 5G NR, the expected RSTD value is a single value that is defined as the RSTD that the UE 104 expects to measure (at the location of the UE 104). The expected RSTD has a value range of + / -500 microseconds (μs). When any resources used for DL ​​positioning measurements are located in FR1, the expected RSTD uncertainty has a value range of + / -32μs. When all resources used for DL ​​positioning measurements are located in FR2, the expected RSTD uncertainty has a value range of + / -8μs. The OTDOA assistance information may also include PRS configuration information parameters that allow the UE 104 to determine when PRS positioning opportunities occur on signals received from various neighboring cells relative to PRS positioning opportunities for a reference cell, and determine the PRS sequences sent from various cells in order to measure signal arrival time (ToA) or RSTD.

[0095] By using RSTD measurements, known absolute or relative transmission timing for each cell, and known locations of wireless node physical transmit antennas for the reference cell and neighboring cells, the location of UE 104 may be calculated (e.g., by UE 104 or by location server 230 / LMF 270). More specifically, the RSTD of neighboring cell "k" relative to reference cell "Ref" may be given as (TOA k -TOA Ref ), where the TOA value may be measured modulo one subframe duration (1 ms) to remove the effect of measuring different subframes at different times. The TOA measurements for different cells may then be converted into RSTD measurements and sent by the UE 104 to the location server 230 / LMF 270. The location of the UE 104 may be determined using (i) RSTD measurements, (ii) known absolute or relative transmission timing for each cell, (iii) known locations of physical transmit antennas for reference cells and neighboring cells, and / or (iv) directional PRS characteristics such as transmission direction.

[0096] A set of resource elements used to transmit PRS is called a "PRS resource". A set of resource elements may span multiple physical resource blocks (PRBs) in the frequency domain and N (e.g., 1 or more) consecutive symbols within a slot 414 in the time domain. In a given OFDM symbol, one PRS resource occupies consecutive PRBs. A PRS resource is described by at least the following parameters: a PRS resource identifier (ID), a sequence ID, a comb size-N, a resource element offset in the frequency domain, a starting slot and a starting symbol, the number of symbols per PRS resource (i.e., the duration of the PRS resource), and QCL information (e.g., QCL with other DL reference signals). Currently, one antenna port is supported. The comb size indicates the number of subcarriers carrying PRS in each symbol. For example, a comb size of comb-4 means that every fourth subcarrier of a given symbol carries PRS.

[0097] A "PRS resource set" is a collection of PRS resources used to transmit a PRS signal, where each PRS resource has a PRS resource ID. In addition, the PRS resources in a PRS resource set are associated with the same TRP. A PRS resource set is identified by a PRS resource set ID and can be associated with a specific TRP (identified by a cell ID) sent by the antenna panel of the base station. The PRS resource ID in a PRS resource set is associated with a single beam (and / or beam ID) sent from a single TRP (where the TRP can send one or more beams). That is, each PRS resource of a PRS resource set can be sent on a different beam, so a "PRS resource" (or simply "resource") can also be referred to as a "beam". It should be noted that this has no effect on whether the UE is aware of the TRP and the beam on which the PRS is sent.

[0098] A "PRS instance" or "PRS opportunity" is an instance of a periodically repeating time window (e.g., a set of one or more consecutive time slots) in which a PRS is expected to be sent. A PRS opportunity may also be referred to as a "PRS positioning opportunity", "PRS positioning instance", "positioning opportunity", "positioning instance", or simply "opportunity" or "instance".

[0099] Figure 5 An exemplary PRS configuration 500 for a cell supported by a wireless node (such as base station 102) is shown. Figure 5 PRS transmission for LTE is assumed in Figure 5 Various aspects of PRS transmission that are the same or similar to those shown and described in the specification may be applied to NR and / or other wireless technologies. Figure 5 shows how to use the system frame number (SFN), cell-specific subframe offset (Δ PRS )552 and PRS periodicity (T PRS)520 to determine the PRS positioning opportunity. Typically, the cell-specific PRS subframe configuration is determined by a “PRS configuration index” included in the OTDOA assistance data. PRS Definition. PRS periodicity (T PRS )520 and cell-specific subframe offset (Δ PRS ) is based on PRS configuration index I PRS The definition is shown in Table 1 below.

[0100]

[0101]

[0102] Table 1

[0103] The PRS configuration is defined with reference to the system frame number (SFN) of the cell that transmits the PRS. PRS In the first subframe of a downlink subframe, the PRS instance may satisfy:

[0104]

[0105] Among them, n f is SFN (where 0≤n f ≤1023), n s By n f The timeslot number within a defined radio frame (where 0≤n s ≤19), T PRS is the PRS periodicity 520, Δ PRS It is the cell-specific subframe offset 552.

[0106] like Figure 5 As shown, the cell-specific subframe offset Δ PRS 552 may be defined based on the number of subframes transmitted from system frame number 0 (time slot 'number 0', denoted as time slot 550) to the start of the first (subsequent) PRS positioning opportunity. Figure 5 In the example of FIG. 5 , in each of the consecutive PRS positioning opportunities 518 a, 518 b, and 518 c, the consecutive positioning subframes (N PRS ) is equal to 4.

[0107] In some aspects, when UE 104 receives the PRS configuration index I in the OTDOA assistance data for a particular cell, PRS When UE104 can use Table 1 to determine the PRS periodicity T PRS 520 and PRS subframe offset Δ PRSUE 104 may then determine the radio frame, subframe, and time slot when scheduling PRS in the cell (e.g., using equation (1)). The OTDOA assistance data may be determined by, for example, location server 172, and include assistance data for a reference cell and a plurality of neighboring cells supported by various wireless nodes.

[0108] Typically, the PRS opportunities from all cells in the network using the same frequency are aligned in time and may have a fixed known time offset (e.g., cell-specific subframe offset 552) relative to other cells in the network using different frequencies. In a SFN synchronous network, all wireless nodes (e.g., base stations 102) may be aligned on frame boundaries and system frame numbers. Thus, in a SFN synchronous network, all cells supported by various wireless nodes may use the same PRS configuration index for any specific frequency of PRS transmission. On the other hand, in a SFN asynchronous network, various wireless nodes may be aligned on frame boundaries but not on system frame numbers. Thus, in a SFN asynchronous network, the PRS configuration index for each cell may be individually configured by the network so that the PRS opportunities are aligned in time.

[0109] The UE 104 can determine the timing of the PRS opportunities of the reference cell and the neighboring cells for OTDOA positioning, provided that the UE 104 can obtain the cell timing (e.g., SFN) of at least one of the cells (e.g., the reference cell or the serving cell). Then, the timing of other cells can be derived by the UE 104 based on the assumption that, for example, the PRS opportunities from different cells overlap.

[0110] For an LTE system, the sequence of subframes used to send PRS (e.g., for OTDOA positioning) can be characterized and defined by multiple parameters, as described above, including: (i) a reserved bandwidth block (BW), (ii) a configuration index I PRS (iii) Duration N PRS , (iv) an optional silence pattern; and (v) a silence sequence periodicity T REP , which may be implicitly included as part of the muting pattern in (iv) (when present). In some cases, where the PRS duty cycle is quite low, N PRS =1,T PRS = 160 subframes (equivalent to 160ms), BW = 1.4, 3, 5, 10, 15 or 20MHz. In order to increase the PRS duty cycle, N PRS The value can be increased to six (ie N PRS =6), the bandwidth (BW) value can be increased to the system bandwidth (ie, in the case of LTE, BW = LTE system bandwidth). PRS(e.g., greater than six) and / or a shorter T PRS (e.g., less than 160 ms) of extended PRS (up to full duty cycle (i.e., N PRS =T PRS )) can also be used in later versions of LPP. The directional PRS can be configured as just described, and can use a low PRS duty cycle (e.g., NPR=1, T PRS =160 subframes) or high duty cycle.

[0111] Figure 6 An exemplary PRS configuration 600 including a PRS muting sequence in LTE is shown. Figure 5 Same, Figure 6 shows how to use SFN, cell-specific subframe offset (Δ PRS )652 and PRS periodicity (T PRS )620 to determine the PRS positioning timing. Figure 6 As shown, the cell-specific subframe offset Δ PRS 652 may be defined based on the number of subframes transmitted starting from system frame number 0 (time slot 'number 0', denoted as time slot 650) to the start of the first (subsequent) PRS positioning opportunity. Figure 6 In the example of FIG. 6 , in each of the consecutive PRS positioning opportunities 618 a and 618 b, the consecutive positioning subframes (N PRS ) is equal to 4.

[0112] In each positioning opportunity, PRS is usually sent at constant power. PRS can also be sent at zero power (i.e., silenced). When PRS signals between different cells overlap because they occur simultaneously or almost simultaneously, it may be useful to turn off the silence of regularly scheduled PRS transmissions. In this case, PRS signals from certain cells can be silenced, while PRS signals from other cells are sent (e.g., at constant power). Silence can help UEs (such as UE 104) to perform signal acquisition and ToA and RSTD measurements on PRS signals that are not silenced (by avoiding interference from PRS signals that have been silenced). For example, when a (strong) PRS signal received by UE 104 from one base station 102 is silenced, a (weak) PRS signal from a neighboring base station 102 can be more easily detected by UE 104. Silence can be regarded as not sending PRS for a given positioning opportunity for a specific cell. A bit string can be used to signal a silence pattern (also referred to as a silence sequence) to UE 104. For example, in the bit string signaled to indicate the muting pattern, if the bit at position j is set to '0', the UE 104 may infer that the PRS is muted for the jth positioning occasion.

[0113] refer to Figure 6 , silent sequence periodicity T REP 630 includes two consecutive PRS positioning opportunities 618a and 618b, followed by two consecutive silent PRS positioning opportunities 618c and 618d. In LTE, the PRS muting configuration of a cell consists only of a periodic muting sequence (e.g., a periodicity of the muting sequence T REP 630), which is the opposite of a non-periodic or semi-persistent silent sequence. Therefore, two consecutive PRS positioning opportunities 618a and 618b followed by two consecutive silent PRS positioning opportunities 618c and 618d will be for the next silent sequence periodicity T REP 630 repetitions.

[0114] To further improve the measurability of the PRS, the positioning subframe may be a low-interference subframe transmitted without a user data channel. Thus, in an ideally synchronized network, the PRS may receive interference from PRSs of other cells with the same PRS pattern index (i.e., with the same frequency shift) rather than from data transmission. In LTE, the frequency shift is defined, for example, as a function of the PRS ID of the cell or other transmission point (TP) (denoted by ) or, if no PRS ID is assigned, a function of the physical cell identifier (PCI) (denoted by ), which results in an effective frequency reuse factor of 6.

[0115] Still to improve the measurability of the PRS (e.g., when the PRS bandwidth is limited to, for example, only 6 resource blocks corresponding to a 1.4 MHz bandwidth), the frequency band for consecutive PRS positioning occasions (or consecutive PRS subframes) may be changed via frequency hopping in a known and predictable manner. In addition, a cell supported by a wireless node may support more than one PRS configuration (e.g., PRS configuration 400 / 500), each of which may include a specific frequency offset (vshift), a specific carrier frequency, a specific bandwidth, a specific code sequence, and / or a specific number of subframes per positioning occasion (N). PRS ) and specific periodicity (T PRS ) of the PRS positioning opportunity. In some implementations, one or more PRS configurations supported in a cell may be used for directional PRS and may then have additional specific characteristics (such as a specific transmission direction, a specific horizontal angle range, and / or a specific vertical angle range). Further enhancements to PRS may also be supported by the wireless node.

[0116] Figure 7 An exemplary wireless communication system 700 is shown in accordance with various aspects of the present disclosure. Figure 7In an example, a UE 704 (e.g., any one of the UEs described herein) is attempting to compute an estimate of its location, or assist another entity (e.g., a base station or core network component, another UE, a location server, a third-party application, etc.) in computing an estimate of its location. The UE 704 may wirelessly communicate with a plurality of base stations 702-1, 702-2, and 702-3 (collectively, base stations 702), which may correspond to any of the base stations described herein, using RF signals and standardized protocols for modulating the RF signals and exchanging information packets. By extracting different types of information from the exchanged RF signals and utilizing the layout of the wireless communication system 700 (i.e., base station locations, geometry, etc.), the UE 704 may determine its location, or may assist in determining its location in a predefined reference coordinate system. In one aspect, the UE 704 may specify its location using a two-dimensional coordinate system; however, the aspects disclosed herein are not limited thereto, and may also be applicable to determining a location using a three-dimensional coordinate system where additional dimensions are anticipated. Additionally, although Figure 7 One UE 704 and three base stations 702 are shown, but as will be appreciated, there may be more UEs 704 and more or fewer base stations 702 .

[0117] To support position estimation, the base station 702 may be configured to broadcast reference RF signals (e.g., PRS, CRS, CSI-RS, synchronization signals, etc.) to the UE 704 in its coverage area, so that the UE 704 can measure the characteristics of such reference RF signals. For example, the UE 704 may use an OTDOA positioning method, and the UE 704 may measure the RSTD between specific reference RF signals (e.g., PRS, CRS, CSI-RS, etc.) transmitted by different pairs of network nodes (e.g., the base station 702, antennas of the base station 702, etc.).

[0118] Typically, at a reference network node (e.g. Figure 7 ) and one or more neighboring network nodes (e.g., Figure 7RSTD is measured between base stations 702-2 and 702-3 in the example of UE 704). For any single positioning use of OTDOA, the reference network node remains the same for all RSTDs measured by UE 704, and the reference network node will typically correspond to a serving cell for UE 704 or another nearby cell with good signal strength at UE 704. In one aspect, where the measuring network node is a cell supported by a base station, the neighboring network nodes will typically be cells supported by a different base station than the base station of the reference cell and may have good or poor signal strength at UE 704. The position calculation may be based on the measured time differences (e.g., RSTD) and knowledge of the locations and relative transmission timing of the network nodes (e.g., whether the network nodes are accurately synchronized, or whether each network node transmits at some known time difference relative to the other network nodes).

[0119] To assist in positioning operations, a location server (e.g., location server 230, LMF 270) may send a reference network node (e.g., Figure 7 ) and neighboring network nodes relative to a reference network node (e.g., base station 702-1 in the example of Figure 7 The OTDOA assistance data may be provided to the UE 704 of the example of the base stations 702-2 and 702-3 in FIG. 1 . For example, the assistance data may provide the center channel frequency of each network node, various reference RF signal configuration parameters (e.g., the number of consecutive positioning subframes, the periodicity of the positioning subframes, the silent sequence, the frequency hopping sequence, the reference RF signal ID, the reference RF signal bandwidth), the network node global ID, and / or other cell-related parameters applicable to OTDOA, as described above. The OTDOA assistance data may also indicate the serving cell of the UE 704 as the reference network node.

[0120] In an aspect, although a location server (e.g., location server 230, LMF 270) can send assistance data to UE 704, alternatively, the assistance data can originate directly from the network node (e.g., base station 702) itself (e.g., in a periodically broadcast overhead message, etc.). Alternatively, UE 704 can detect neighboring network nodes itself without using assistance data.

[0121] exist Figure 7In the example of , the measured time differences between the reference cell of base station 702-1 and the neighboring cells of base stations 702-2 and 702-3 are represented as τ2-τ1 and τ3-τ1, where τ1, τ2 and τ3 represent the transmission time of the reference RF signal from the transmit antennas of base stations 702-1, 702-2 and 702-3 to UE 704, respectively, and include any measurement noise at UE 704. UE 704 can then convert the ToA measurements for different network nodes into RSTD measurements and (optionally) send them to the location server. The location of UE 704 can be determined (by UE 704 or location server) by using (i) RSTD measurements, (ii) known absolute or relative transmission timing of each network node, (iii) known locations of physical transmit antennas for reference cell and neighboring network nodes, and / or (iv) directional reference RF signal characteristics (such as transmission direction).

[0122] The ToA of the shortest path from UE 704 to base station i is i for Among them, D i is a position (q i ) and the Euclidean distance between the base station i and the UE 704 with position (p), c is the speed of light in air (299700 km / s), and q i The Euclidean distance (i.e. the line distance between two points) is given by the following formula:

[0123]

[0124] Where D is the distance between two points on the Earth's surface, R is the Earth's radius (6371 km), are the latitude of the first point (expressed in radians) and the latitude of the second point (expressed in radians), β1 and β2 are the longitude of the first point (expressed in radians) and the latitude of the second point (expressed in radians), respectively.

[0125] In order to identify the ToA of the reference RF signal sent by a given network node, the UE 104 first jointly processes all resource elements (REs) on the channel on which the network node (e.g., base station 702) sends the reference RF signal, and performs an inverse Fourier transform to convert the received RF signal to the time domain. The conversion of the received RF signal to the time domain is called an estimate of the channel energy response (CER). The CER shows the peaks on the channel that change over time, so the earliest "significant" peak should correspond to the ToA of the reference RF signal. Typically, the UE will use a quality threshold related to noise to filter out false local peaks, thereby roughly correctly identifying the significant peaks on the channel. For example, the UE 704 can select a ToA estimate that is the earliest local maximum of the CER, which is at least X dB higher than the median of the CER and a maximum of Y dB lower than the main peak on the channel. The UE 704 determines the CER for each reference RF signal from each network node in order to determine the ToA of each reference RF signal from different network nodes.

[0126] When the UE 704 itself obtains a position estimate by measuring the time difference using OTDOA, the necessary additional data (e.g., the locations and relative transmission timings of network nodes) may be provided to the UE 704 by a location server (e.g., location server 230, LMF 270). In some implementations, the position estimate of the UE 704 may be obtained (e.g., by the UE 704 itself or by a location server) from the OTDOA measured time difference and other measurements made by the UE 704 (e.g., measurements of signal timing from global positioning system (GPS) or other global navigation satellite system (GNSS) satellites). In these implementations, which are referred to as hybrid positioning, the OTDOA measurements may help obtain a position estimate for the UE 704, but may not completely determine the position estimate.

[0127] Uplink time difference of arrival (UTDOA) is a positioning method similar to OTDOA, but is based on an uplink reference RF signal transmitted by a UE (e.g., UE 704). In addition, transmit and / or receive beamforming at the network node and / or UE 704 can enable wideband bandwidth at the cell edge, thereby improving accuracy. Beam refinement can also exploit channel reciprocity processes in NR.

[0128] As used herein, a "network node" may be a base station (e.g., base station 102), a cell of a base station (e.g., a cell of base station 102), a remote radio head, an antenna of a base station (e.g., an antenna of base station 102, where the antenna of the base station is located differently from the location of the base station itself), an antenna array of a base station (e.g., an antenna array of base station 102, where the location of the antenna array is different from the location of the base station itself), or any other network entity capable of sending a reference RF signal. In addition, as used herein, a "network node" may refer to a network node or a UE.

[0129] The term "position estimate" is used herein to refer to an estimate of the location of a UE (e.g., UE 104), which estimate may be geographic (e.g., may include latitude, longitude, and possibly altitude) or civic (e.g., may include a street address, a building name, or a precise point or area within or near a building or street address, such as a specific entrance to a building, a specific room or suite in a building, or a landmark (such as a town square)). A position estimate may also be referred to as a "location," "position," "fix," "position fix," "location fix," "location estimate," "fix estimate," or some other term. The manner in which a position estimate is obtained may generally be referred to as "positioning," "addressing," or "position determination." A specific solution for obtaining a position estimate may be referred to as a "position solution." A specific method for obtaining a position estimate as part of a position solution may be referred to as a "position method" or as a "positioning method."

[0130] Fig. 8A and Figure 8B A performance comparison between Comb-1 and Comb-4 is shown. As used herein, the term "Comb-N" means that 1 out of every N subcarriers of a given bandwidth for a given symbol contains a PRS, without frequency interleaving (i.e., all OFDM symbols carrying PRS contain PRS on the same subcarrier). It should be understood that for Comb-1, every subcarrier of the transmission bandwidth contains a PRS, while in the case of Comb-4, 1 out of every 4 subcarriers of the transmission bandwidth contains a PRS. Fig. 8A In FIG. 810 , each shaded block represents a resource element / subcarrier containing a PRS. Comb 1 (full comb) diagram 810 shows that each subcarrier has a PRS that can be obtained by the UE. It should be understood that not all PRSs must be in the same OFDM symbol, but can be scattered among various OFDM symbols. In any case, the UE will sample the PRS in each subcarrier / frequency tone.

[0131] In contrast, diagram 820 of a comb-4 pattern (without additional frequency interleaving) is shown with several resource elements / subcarriers without PRS to be sampled (eg, null blocks) and PRS in every fourth subcarrier / tone. Figure 8B 8 is a graph 850 showing the performance difference between a comb-1 PRS configuration and a comb-4 PRS configuration. It can be seen that the performance loss occurs in the tail of the cumulative distribution function (CDF) (after the 60% percentile). Comb-4 has a 6dB better energy per resource element (EPRE) ratio. While the performance is better with the comb-1 configuration, it also increases the overhead and reduces the effective bandwidth of a given subframe, so it is advantageous to use less than all subcarriers in a subframe for PRS transmission.

[0132] Fig. 9 900 is a graph showing Comb-4 CER and potential aliasing issues. If the cells are far apart, aliasing may occur due to subsampling in the frequency domain. For example, in a Comb-4 PRS configuration, as shown, subsampling in the frequency domain produces multiple peaks (four). The distance to each peak (x-axis, in meters (m)) can be assumed based on the speed of light and the time difference. As shown, there are approximately 1000m between the peaks. In addition, as shown, the strongest peak 910 detected is an alias of the true peak 920. This can produce an offset of 2500m, as shown in FIG. Fig. 9 As shown in the example. When a PRS configuration less than comb-1 is used, the aliasing problem can be alleviated by establishing an RSTD search window based on the estimated position of the UE. For example, the RSTD search window 950 can be -2μs to +2μs near the 100m position. In the case of using the RSTD search window 950, the true peak 920 will be detected and the aliased peak 910 will be discarded, and the correct position will be identified. It will also be understood that the allowed RSTD search window is based on the PRS configuration and / or frequency range (e.g., FR1, FR2). If there is a PRS configuration that does not fully sample the frequency domain, the allowed / maximum size of the uncertainty window should be different to account for different PRS configurations. For example, if the allowed RSTD search window 950 is too large, it will not prevent the detection of aliased peaks (e.g., 910), and therefore, the allowed RSTD search window should be smaller than the peak-to-peak distance caused by subsampling.

[0133] As described above, in LTE systems, a search window centered on the expected RSTD parameter can be provided, and the size of the search window can be the expected RSTD uncertainty parameter. However, the RSTD search window uncertainty and resolution are constant in LTE. These two values ​​together define the search window in which the RSTD can be found for the UE. The expected RSTD is encoded in the LTE Positioning Protocol (LPP) as an integer value between -8192 and +8191 (14 bits). Therefore, the maximum range of the search window is -8192×3×T s ;+8191×3×T s , where T s=1 / (15000×2048) seconds, which results in a search window range of approximately -0.8 ms to +0.8 ms. This value range also supports "partially synchronized" PRS timings (where the maximum offset between transmitted PRS position timings cannot exceed half a subframe (0.5 ms)). For example, if T x is the reception time of the start of subframe X of the auxiliary data reference cell at the target UE, then the target UE may assume that the start of the subframe closest to subframe X of the neighboring cell is at T x The center is [-expectedRSTD-Uncertainty×3×T s ,expectedRSTD-Uncertainty×3×T s ] is received within the search window of . The uncertainty represents the uncertainty of the expected RSTD and is related to the location server's a priori estimate of the target UE's position. However, this coarse range is not configurable and may help with subframe misalignment, but does not help with frequency subsampling and symbol-level aliasing, as discussed above and as Fig. 9 As shown in .

[0134] The allowed range of the RSTD search window may be different and thus configurable for different structures of the PRS. For example, for a comb-12 PRS configuration without frequency domain interleaving, the range of the search window and / or resolution may only allow for smaller values ​​than when the PRS is configured as comb-N and N is less than 12, or if there is frequency domain interleaving (which may allow PRS in all subcarriers). It should be understood that frequency domain interleaving is effectively reduced to a comb-1 PRS configuration (although not transmitted in a single symbol). In the absence of frequency domain interleaving, the PRS will only be available for sampling in a subset of subcarriers of a given bandwidth in the frequency domain. It should be noted that even with frequency interleaving, PRS transmission on one or more subbands of larger bandwidth would still be an example of sampling a subset of subcarriers of a given bandwidth in the frequency domain.

[0135] LTE supports a single numerology (subcarrier spacing (15kHz) and symbol length, etc.). In contrast, NR can support multiple numerologies, for example, 15kHz, 30kHz, 60kHz, 120kHz, and 240kHz or larger subcarrier spacing can be used. Table 2 provided below lists some of the various parameters of different NR numerologies.

[0136]

[0137] Table 2

[0138] In one example, if there is a given parameter set with a subcarrier spacing of 120kHz, then in a 125μs time slot, 14 OFDM symbols can be used. Given a comb-12PRS configuration, the main peak will be repeated or repeated 12 times every 1 / 12 symbol in the time domain, that is, each is 125×1000 / (14×12)=744ns. Therefore, the allowed range of the RSTD search window should not exceed the size of 744ns, and is preferably smaller. If the search window exceeds 744ns, an erroneous peak may occur. It will be understood that the subframe-level uncertainty discussed above is on the order of 0.8ms. In contrast, based on the above PRS configuration, the allowed range of the RSTD search window is on the order of 700ns. Therefore, the uncertainty window at the subframe level does not have an advantage in preventing symbol-level aliasing. In general, for a comb-N PRS configuration in a time slot of T ms size, the allowed range of the RSTD search window should not be greater than T×1000 / (14×N)ns.

[0139] Similarly, for different comb type PRS configurations, the resolution may be different from the fixed value provided in the above LTE (eg, K×T s , K=3). As used herein, the resolution is related to the interval in time between two consecutive values ​​of the expected RSTD. For example, in LTE, the resolution is 3*T s This is because the expected RSTD is encoded in LPP as an integer value between -8192 and +8191 (14 bits), where the maximum search window range is -8192×3×T s ;+8191×3×T s , where T s =1 / (15000×2048) seconds, which results in a search window range of approximately -0.8ms to +0.8ms.

[0140] Typically, for a comb-N PRS configuration (where the allowed range of the RSTD search window is smaller), the resolution is also a smaller value. The possible resolution values ​​may depend on the parameter set, that is, different resolution values ​​may be allowed for different parameter sets. In addition, the resolution values ​​may be set relative to T c To calculate the resolution, so as to better solve the NR parameter set. Throughout the specification, unless otherwise specified, the size of each field in the time domain can be expressed in time units T c =1 / (Δf max ·N f ) is used to represent the max =480·10 3 Hz and N f =4096. Constant k = T s / T c=64, where T s =1 / (Δf ref ·N fref ), Δf ref =15·10 3 Hz and N fref = 2048. In NR, higher accuracy may be required, and this higher accuracy may depend on T c = 0.509ns and parameter set factor. For example, the step size can be T c 2 u , where "u" is one of 0, 1, 2, 3, 4, 5, 6. In general, the resolution can be based on K·T c 2 u The parameter set of K and u generally decreases with the increase of subcarrier spacing. Table 3 below provides K·T for various values ​​of K and u. c 2 u The value of (in ns).

[0141]

[0142] Table 3

[0143] For NR parameter sets with a subcarrier spacing of 15kHz, it may be necessary to remain consistent with LTE. Therefore, for 15kHz, K = 3 and u = 6, which results in the same value of 97.656ns as 3·Ts. However, for other NR parameter sets, the value of u can vary. For example, when the subcarrier spacing is greater than 15kHz, K = {1,2,3} and u = {1,2,3,4,5}.

[0144] In some aspects, adjustments to the allowed range of the RSTD search window can also be associated with the refinement / tracking procedure because the procedure assumes that there is a coarse estimate available to locate the UE to one of the aliased repetitions generated by the Comb-N PRS configuration. For example, if the coarse position estimate is known, this information can be used to limit the RSTD search window to be centered on the coarse position (e.g., 100m position, the above combined Fig. 9 The coarse position together with the configurable RSTD search window can have an allowed range based on the PRS configuration, e.g., comb type and parameter set helps ensure that true peaks and thus true timing / position are detected.

[0145] In some additional aspects, a base station (e.g., a gNB) may configure multiple {RSTD search windows, resolution} or only {RSTD search window} parameters. The gNB may signal (e.g., using downlink control information (DCI) or MAC control element (MAC-CE)) which RSTD search window will apply to a particular PRS configuration, or PRS opportunity, or PRS opportunity group. Aperiodic PRS or semi-persistent PRS configurations may be allowed to have different {RSTD search window, resolution} or {RSTD search window} parameters, or multiple such options, while periodic PRS may use default specified values. These search windows may be configured to be contiguous, but not necessarily.

[0146] For example, Table 4 shows that when the expected RSTD parameter uses a granularity of (where μ1=1,2,3,4,5,6, T c =0.509ns), where . Using 14 bits allows the expected RSTD parameter to represent values ​​from negative 8192 to 8192.

[0147] Configuring μ Expected RSTD range Distance Difference μ=1 [-25,25]μs 4.5km μ=2 [-50,50]μs 12km μ=3 [-100,100]μs 27km μ=4 [-200,200]μs 57km μ=5 [-400,800]μs 117km μ=6 [-800,800]μs 237km

[0148] Table 4

[0149] As another example, Table 5 shows that when the expected RSTD parameter usage granularity is (where μ2=1,2,3,4,5,6, T c =0.509ns), where . Using 10 bits allows the expected RSTD parameter to represent values ​​from negative 0 to 1023.

[0150]

[0151] Table 5

[0152] On the one hand, the size of the RSTD search window may depend on the frequency band (or sub-band). On the one hand, each frequency band may have a search window of different sizes. However, overlapping frequency bands may be allowed to have the same value. On the one hand, the parameters of each search window may be selected from Tables 5 and 6 above. For example, a frequency band (e.g., 28GHz, referred to as "n257") may have a configuration of μ = 3, a minimum expected RSTD-uncertainty of 12.2ns, a maximum expected RSTD-uncertainty of 12.49μs, and an uncertainty distance difference of 3.75km. A second frequency band (e.g., "n41" frequency band) may have a configuration of μ = 6, a minimum expected RSTD-uncertainty of 97.7ns, a maximum expected RSTD-uncertainty of 99.97μs, and an uncertainty distance difference of 30km. In the same example, a first frequency band may have a configuration of μ = 0, an expected RSTD range of [-12.5, 12.5]μs, and a distance difference of 3.75km. The second frequency band may have a configuration μ=3, an expected RSTD range of [-100, 100] μs, and a range difference of 27 km.

[0153] On the one hand, the size of the RSTD search window can depend on the frequency range (e.g., FR1, FR2). On the one hand, each frequency range can have a search window of different sizes, and the search window has parameters different from other search windows. The parameters of each search window can be selected from Tables 5 and 6 above. For example, a frequency range (e.g., FR2) can have a configuration μ = 3, a minimum expected RSTD-uncertainty of 12.2ns, a maximum expected RSTD-uncertainty of 12.49μs, and an uncertainty distance difference of 3.75km. The second frequency range (e.g., FR1) can have a configuration μ = 6, a minimum expected RSTD-uncertainty of 97.7ns, a maximum expected RSTD-uncertainty of 99.97μs, and an uncertainty distance difference of 30km. In the same example, the first frequency range (e.g., FR2) can have a configuration μ = 0, an expected RSTD range of [-12.5, 12.5]μs, and a distance difference of 3.75km. The second frequency range (eg, FR1) may have an expected RSTD range of configuration μ=3, [-100, 100] μs, and a distance difference of 27 km. Note that FR2 is a power-of-two scaled-down version of FR1. In the example above, it is 1 / 8.

[0154] Fig.10Another aspect of the present disclosure is shown, which includes defining the RSTD search window with respect to an alternative base station instead of a serving base station. The RSTD search window is based on the uncertainty of the base station's timing with respect to a reference base station / node (typically a serving base station). However, if the base stations are asynchronous or insufficiently synchronized, the RSTD search window / uncertainty window will be primarily affected by the timing uncertainty between the two base stations and may not be significantly reduced. As an example of a fully synchronized base station, two base stations need to be within 3μs in FR2 and 10μs in FR1 to be considered fully synchronized. NR is divided into two different frequency ranges. For example, FR1 includes frequency bands below 6GHz, while FR2 includes frequency bands in the millimeter wave range. However, these values ​​may vary depending on specific network configurations, transmission frequencies, etc. For example, this may be related to positioning operations in LTE dual connectivity or other multi-RAT configurations, which assume that all positioning processes are run independently in each cell group and that the two cell groups are not well synchronized with each other.

[0155] like Fig.10 As shown, BS1 is the serving base station. Therefore, UE 1004 has performed a PRACH process 1010 with BS1 and it obeys the timing advance (TA) command with respect to a specific base station. In addition, as shown in the figure, it is assumed that there are two neighboring base stations (BS2 and BS3), such that BS2 is not synchronized or is not sufficiently synchronized with respect to BS1, but BS3 is sufficiently synchronized with respect to BS1. For BS3, an RSTD search window can be defined with respect to BS1. However, in order to address this insufficient synchronization with respect to BS2, UE 1004 can be configured to perform an additional PRACH 1020 with the insufficiently synchronized neighboring base station (BS2), which then becomes an alternative base station or alternative node for reference. The RSTD search window can be with respect to the alternative base station / alternative node (i.e., Fig.10 The RSTD search window can be defined with respect to the PRACH timing of BS2 in the example of BS2). The RSTD search window can now be adjusted with respect to BS2 for each base station that is fully synchronized with BS2. For example, as shown in the figure, BS4 is fully synchronized with BS2, but not fully synchronized with BS1 (or BS3). In this case, the RSTD search window of BS4 can be defined with respect to BS2 and can be used for RSTD measurements between BS2 and BS4.

[0156] On the one hand, as an alternative to selecting an approximate integer of microseconds (μs), the search space value of the RSTD search window can also be aligned based on the OFDM symbol length. In the case of symbol alignment for FR1, a symbol duration of a CP including a 60kHz subcarrier spacing (SCS) can be used: 1e6*(144+2048) / (2048*15e3) / 4=17.8385μs. The search space offset of [-107.0313,107.0313] can be supported by a total of 13 symbol offset assumptions {-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6}. In addition to the offset, supporting an additional search space of approximately 50μs will use three symbols, or approximately 53.3μs. In summary, SCS at 60 kHz in FR1 can be supported by a total of 19 symbol assumptions: {-9,-8,-7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7,8,9}. That is, the total coverage will be [-160.5469,160.5469]μs, or approximately ±48km.

[0157] Similarly, for FR2, for 120kHz symbol duration, 1e6*(144+2048) / (2048*15e3) / 8=8.9193μs. In this case, a symbol offset of {-2,-1,0,1,2} will support a search offset range of [-17.8385 17.8385]μs. If a search window of ±1 symbol or 8.9μs is added, it would mean that the seven symbol assumptions {-3,-2,-1,0,1,2,3} would cover a range of ±3*8.9193μs=[-26.7578,26.7578]μs or ±8.02km.

[0158] As a specific example for FR1, assume that the expected RSTD is [-107.0, 107.0] μs, the expected RSTD-uncertainty is [-53.5, 53.5] μs, the range of the supported search space for all TRPs (in μs) is [-160.5, 160.5], the range of the supported search space for all TRPs (in km) is [-48.1, 48.1], and the maximum supported distance between any TRPs used in the same positioning session is 31.2 km. For an SCS of 60 kHz (designed SCS), the search window offset options for each cell at each opportunity can be 13 symbol offsets {-6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6}, corresponding to [-107.0, 107.0] μs. The search window size for each cell at each opportunity may be a total of seven offsets {-3,-2,-1,0,1,2,3} corresponding to [-53.5,53.5] μs. The complete search range for all cells per positioning session may be a total of 19 offsets {-9,-8,-7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7,8,9} corresponding to [-160.5,160.5] μs.

[0159] Continuing to refer to the specific FR1 example above, for a 30kHz SCS (derived from a 60kHz SCS), the search window offset options for each cell at each opportunity can be seven symbol offsets {-3, -2, -1, 0, 1, 2, 3}, corresponding to [-107.0, 107.0] μs. The search window size for each cell at each opportunity can be a total of five offsets {-2, -1, 0, 1, 2}, corresponding to [-71.4, 71.4] μs. The complete search range for all cells for each positioning session can be a total of 11 offsets {-5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5}, corresponding to [-178.4, 178.4] μs. Note that for a 30kHz SCS, the symbol is twice the duration of the symbol for the 60KHz SCS. Therefore, the six symbols of the 60kHz SCS have the same duration as the three symbols of the 30KHz SCS.

[0160] Continuing with the specific FR1 example above, for a 15kHz SCS (derived from a 60kHz SCS), the search window offset options for each cell at each opportunity can be 5 symbol offsets {-2, -1, 0, 1, 2}, corresponding to [-142.7, 142.7] μs. The search window size for each cell at each opportunity can be a total of three offsets {-1, 0, 1}, corresponding to [-71.4, 71.4] μs. The complete search range for all cells for each positioning session can be a total of seven offsets {-3, -2, -1, 0, 1, 2, 3}, corresponding to [-214.1, 214.1] μs. Note that five total offsets can be used for a 15kHz SCS because each hypothesis spans [-0.5, 0.5] symbols. Note that 2.5 symbols are 178.4 μs to 160.5 μs.

[0161] As a specific example for FR2, assume that the expected RSTD is [-13.3789, 13.3789] μs, the expected RSTD-uncertainty is [-13.3789, 13.3789] μs, the range of the supported search space for all TRPs (in μs) is [-26.7578, 26.7578], the range of the supported search space for all TRPs (in km) is [-8.02, 8.02], and the maximum supported distance between any TRPs used in the same positioning session is 8.02 km. For an SCS of 240 kHz (designed SCS), the search window offset options for each cell at each opportunity can be seven symbol offsets {-3, -2, -1, 0, 1, 2, 3}, corresponding to [-13.4, 13.4] μs. The search window size for each cell per opportunity may be a total of seven offsets {-3, -2, -1, 0, 1, 2, 3} corresponding to [-13.4, 13.4] μs. The complete search range for all cells per positioning session may be a total of 13 offsets {-6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6} corresponding to [-26.8, 26.8] μs.

[0162] Continuing with the specific FR2 example above, for a 104kHz SCS (derived from a 240kHz SCS), the search window offset options for each cell at each opportunity can be five symbol offsets {-2, -1, 0, 1, 2}, corresponding to [-17.8, 17.8] μs. The search window size for each cell at each opportunity can be a total of five offsets {-2, -1, 0, 1, 2}, corresponding to [-17.8, 17.8] μs. The complete search range for all cells per positioning session can be a total of seven offsets {-4, -3, -2, -1, 0, 1, 2, 3, 4}, corresponding to [-26.8, 26.8] μs.

[0163] Continuing with the specific FR2 example above, for a 60kHz SCS (derived from a 240kHz SCS), the search window offset options for each cell at each opportunity can be 3 symbol offsets {-1,0,1}, corresponding to [-17.8,17.8]μs. The search window size for each cell at each opportunity can be a total of three offsets {-1,0,1, corresponding to [-17.8,17.8]μs. The complete search range for all cells per positioning session can be a total of five offsets {-2,-1,0,1,2}, corresponding to [-35.7,35.7]μs.

[0164] As briefly mentioned above, in NR, frequency bands may overlap in frequency, i.e. conflict. Fig.11 In the example, for a bandwidth of 900 MHz, band n77 ranges from 3300 MHz (3.3 GHz) to 4200 MHz (4.2 GHz). In addition, for a bandwidth of 500 MHz, band n78 ranges from 3300 MHz (3.3 GHz) to 3800 MHz (3.8 GHz). In other words, the entire band n78 conflicts with band n77. Fig.12 Some FR1 and FR2 frequency bands and their overlaps are shown. For example, in FR1, band n1 at least partially overlaps bands n2, n25, and n66, and also completely overlaps band n84. For another example, in FR2, band n257 partially overlaps band n258 and completely overlaps band n261.

[0165] Fig.13 A method 1300 of operating a network entity 1305 according to various aspects of the present disclosure is shown. It should be understood that the network entity 1305 can be any network element or combination of network elements capable of performing the functional aspects described. For example, the network entity 1305 can be a base station 102 (and the above-mentioned variations), a location server 230 or an LMF 270, or a combination of a base station and a location server. In box 1310, the method 1300 includes configuring an RSTD search window based on a PRS configuration (and / or a frequency range (e.g., FR1, FR2)). In box 1320, the RSTD search window is provided to the UE. The RSTD search window can be provided as part of the OTDOA assistance data provided to the UE. In 1330, the method 1300 includes sending a plurality of PRSs to the UE, each PRS having a PRS configuration. The PRS can be sent in a subset of all subcarriers less than a given bandwidth.

[0166] Generally, as described above, for different structures of reference signals used for positioning, the allowed range of the search window may be different. For example, the allowed range of the comb-N PRS configuration is greater than the allowed range of the comb-M PRS configuration, and where N is less than M and N is greater than 1. It will be understood that as N increases, the allowed range decreases.

[0167] Fig.14 A method 1400 of operating a UE 1404 (e.g., any UE described herein) in accordance with various aspects of the present disclosure is shown. In box 1410, an RSTD search window (with an allowed range) based on a PRS configuration (and / or a frequency range (e.g., FR1, FR2)) is received from a network node. In box 1420, multiple PRSs are received from the network node, each PRS having a PRS configuration. The PRS may be sent in a subset that is less than all subcarriers over a given bandwidth. In box 1430, an RSTD between the network node and a reference node is determined based on the RSTD search window. It should be understood that, as discussed herein, the network node and the reference node may be each of a base station, an access point, or a transmission point belonging to the same base station. Once the RSTD is determined, the UE may report the RSTD to a network entity (e.g., a base station, a location server, etc.) and / or use the RSTD to determine the location of the UE for UE-based positioning. In other aspects, the UE may determine that the network node is not sufficiently synchronized with the reference node serving the UE, such as in conjunction with the above. Fig.10 As discussed above. For example, the serving base station may send information about the synchronization capabilities of other nearby base stations. Once identified, then, to resolve the RSTD search window and assistance data from the insufficiently synchronized network node, the UE may perform a PRACH procedure with the alternative node, where the RSTD search window serves as a reference for the alternative node that is sufficiently synchronized with the network node.

[0168] Fig.15 A method 1500 of operating a location server in accordance with aspects of the present disclosure is shown. In block 1510, the location server determines an RSTD search window based on a PRS configuration (and / or frequency range (e.g., FR1, FR2)). In block 1520, the location server provides the RSTD search window to a UE or a base station serving the UE. In block 1530, the location server configures a plurality of PRSs to be sent to the UE, each PRS having a PRS configuration in which the PRS is to be sent in a subset of less than all subcarriers over a given bandwidth.

[0169] It should be understood that any reference to an element using names such as "first", "second" and the like herein generally does not limit the quantity or order of these elements. On the contrary, these names can be used as a convenient method to distinguish two or more elements or element instances in this article. Therefore, the reference to the first element and the second element does not mean that only two elements can be adopted here, or the first element must be located before the second element in some way. Similarly, unless otherwise stated, an element set may include one or more elements. In addition, the term form "at least one of A, B or C" or "one or more of A, B or C" or "at least one of the group consisting of A, B and C" used in the specification or claims means "A or B or C or any combination of these elements". For example, this term can include A, or B, or C, or A and B, or A and C, or A and B and C, or 2A, or 2B, or 2C, etc.

[0170] In view of the above description and explanation, it will be appreciated by those skilled in the art that the multiple illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the various aspects disclosed herein may be implemented as electronic hardware, computer software, or a combination of the two. In order to clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the entire system. Those skilled in the art may implement the described functionality in different ways for each specific application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

[0171] Thus, it should be appreciated that, for example, a device or any component of a device may be configured (or operable or adapted) to provide the functionality taught herein. This may be achieved, for example, by manufacturing (e.g., making) a device or component so that it will provide the functionality; by programming a device or component so that it will provide the functionality; or by using some other suitable implementation technique. As one example, an integrated circuit may be fabricated to provide the requisite functionality. As another example, an integrated circuit may be fabricated to support the requisite functionality and then configured (e.g., by programming) to provide the requisite functionality. As yet another example, a processor circuit may execute code to provide the requisite functionality.

[0172] In addition, the methods, sequences and / or algorithms described in conjunction with the various aspects disclosed herein may be directly embodied in hardware, in a software module executed by a processor, or in a combination of the two. The software module may reside in a random access memory (RAM), a flash memory, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor so that the processor can read information from the storage medium and write information to the storage medium. In an alternative, the storage medium may be integrated with a processor (e.g., a cache memory).

[0173] Thus, for example, it will also be appreciated that certain aspects of the invention may comprise a computer-readable medium embodying the methods as described herein.

[0174] Although the foregoing shows a number of illustrative aspects, it should be noted that various changes and modifications may be made to the illustrated examples without departing from the scope as defined in the appended claims. The present invention is not intended to be limited to the specifically illustrated examples. For example, unless otherwise indicated, the functions, steps, and / or actions of the method claims according to the various aspects of the present disclosure described herein need not be performed in any particular order. In addition, although certain aspects may be described or claimed in singular form, plural forms are also encompassed unless limitation to the singular form is explicitly stated.

Claims

1. A method of operating a network entity, comprising: obtaining a reference signal timing difference (RSTD) search window based on a positioning reference signal (PRS) configuration, wherein the RSTD search window is defined by an expected RSTD parameter and an RSTD uncertainty parameter, wherein the RSTD search window has an allowed range based on the PRS configuration, and wherein a different size of the RSTD search window is determined for each frequency range associated with the PRS configuration; Providing the RSTD search window to a user equipment UE; as well as A plurality of PRSs defined by the PRS configuration are transmitted to the UE, wherein the plurality of PRSs are transmitted in a subset of subcarriers that is less than all subcarriers over a given bandwidth.

2. The method according to claim 1, wherein: The allowed range of the comb-N PRS configuration is greater than the allowed range of the comb-M PRS configuration, and wherein N is less than M.

3. The method according to claim 2, wherein: N is greater than 1.

4. The method according to claim 1, wherein: The allowed range is inversely proportional to a Comb-N PRS configuration without frequency interleaving.

5. The method according to claim 1, wherein: The allowable range is on the order of nanoseconds ns.

6. The method according to claim 1, wherein: The allowed range is based on a parameter set of the PRS configuration.

7. The method according to claim 6, wherein: The allowed range is no greater than T·1000 / (14·N) nanoseconds, wherein T is a time slot size in microseconds μs, and wherein the PRS configuration is comb-N.

8. The method according to claim 1, wherein: Obtaining the RSTD search window based on the PRS configuration includes: A different RSTD search window is obtained for each frequency range associated with the PRS configuration.

9. The method according to claim 1, wherein: The resolution value of the RSTD search window is K·T c 2 u , where T c =1 / (480,000·4096), and wherein K={1,2,3} and u={1,2,3,4,5,6}.

10. The method according to claim 9, wherein: The selected value of K or u is based on the parameter set of the PRS configuration.

11. The method according to claim 10, wherein: Based on a numerology set with 15 kHz subcarrier spacing, K=3 and u=6.

12. The method according to claim 10, wherein: For any parameter set with subcarrier spacing greater than 15 kHz, K is selected from the integers 1, 2, or 3, and u is less than 6.

13. The method according to claim 9, wherein: The selected value of K or u is configured.

14. The method according to claim 9, wherein: The expected RSTD parameter uses a granularity 14 bits to encode, where u1 = {1, 2, 3, 4, 5, 6}, and T c It is 0.509 nanoseconds.

15. The method according to claim 9, wherein: The RSTD uncertainty parameters are given using a granularity 10 bits to encode, where u2 = {1, 2, 3, 4, 5, 6}, and T c It is 0.509 nanoseconds.

16. The method according to claim 15, wherein: u1 and u2 are different.

17. The method according to claim 1, wherein: Providing the RSTD search window also includes: configuring multiple allowed ranges for multiple RSTD search windows; and The plurality of RSTD search windows having the plurality of allowed ranges are provided to the UE.

18. The method according to claim 17, wherein: At least one of the plurality of RSTD search windows is associated with a resolution.

19. The method according to claim 17, further comprising: The UE is signaled which of the multiple RSTD search windows applies to a PRS configuration, a PRS opportunity, a PRS instance, or a PRS opportunity group.

20. The method according to claim 19, wherein: The UE is signaled using downlink control information DCI or medium access control MAC control element CE.

21. The method of claim 17, further comprising: A report is received from the UE reporting the RSTD determined for the plurality of RSTD search windows.

22. The method according to claim 17, wherein: A different one of the plurality of RSTD search windows is configured for each frequency band on which the UE is expected to measure the plurality of PRSs.

23. The method according to claim 17, wherein: A different one of the plurality of RSTD search windows is configured for each frequency range in which the UE is expected to measure the plurality of PRSs.

24. The method according to claim 1, wherein: The PRS configuration is an aperiodic PRS or a semi-persistent PRS.

25. The method of claim 1, further comprising: A position estimate of the UE is obtained, wherein the accuracy of the position estimate is less than aliased repetitions produced by a Comb-N PRS configuration.

26. The method according to claim 25, wherein: The position estimate of the UE is obtained while tracking the UE.

27. The method of claim 1, wherein: The network entity is not sufficiently synchronized with a serving base station of the UE, and wherein the RSTD search window is referenced to an alternative base station that is sufficiently synchronized with the network entity.

28. The method according to claim 27, wherein: The UE is configured to perform a physical random access channel (PRACH) procedure with the alternative base station.

29. The method of claim 1, wherein: The network entity is a base station.

30. The method of claim 29, wherein: The obtaining includes receiving the RSTD search window from a location server.

31. The method of claim 29, wherein: The obtaining includes configuring the RSTD search window at the base station.

32. The method of claim 1, wherein: The RSTD search window is provided as part of the downlink positioning reference signal assistance information, and The size of the RSTD search window is provided in the downlink positioning reference signal auxiliary information as the number of one or more orthogonal frequency division multiplexing OFDM symbols.

33. The method of claim 32, wherein: The number of the one or more OFDM symbols is based on a frequency range in which the UE is expected to measure the plurality of PRSs.

34. The method of claim 32, wherein: Each of the following is represented by a number of one or more OFDM symbols: the search window offset per cell per opportunity parameter, the search window size per cell per opportunity parameter, and the complete search range for all cells per positioning session parameter.

35. The method of claim 1, wherein: The frequency range of the plurality of PRSs is FR1, the range of FR1 is from 450 MHz to 6000 MHz, and The value of the RSTD uncertainty parameter is + / - 32 microseconds.

36. The method of claim 1, wherein: The frequency range of the plurality of PRSs is FR2, the range of FR2 is from 24250 MHz to 52600 MHz, and The value of the RSTD uncertainty parameter is + / - 8 microseconds.

37. A method of operating a user equipment UE, comprising: receiving a reference signal timing difference (RSTD) search window based on a positioning reference signal (PRS) configuration, wherein the RSTD search window is defined by an expected RSTD parameter and an RSTD uncertainty parameter, wherein the RSTD search window has an allowed range based on the PRS configuration, and wherein a different size of the RSTD search window is determined for each frequency range associated with the PRS configuration; receiving, from a network node, a plurality of PRSs defined by the PRS configuration, wherein the plurality of PRSs are transmitted in a subset of subcarriers that is less than all subcarriers over a given bandwidth; and An RSTD between the network node and a reference node is determined based on the RSTD search window.

38. The method of claim 37, wherein: The allowed range of the comb-N PRS configuration is greater than the allowed range of the comb-M PRS configuration, and wherein N is less than M.

39. The method of claim 38, wherein: N is greater than 1.

40. The method of claim 37, wherein: The allowed range is inversely proportional to a Comb-N PRS configuration without frequency interleaving.

41. The method of claim 37, wherein: The allowable range is on the order of nanoseconds ns.

42. The method of claim 37, wherein: The allowed range is based on a parameter set of the PRS configuration.

43. The method of claim 42, wherein: The allowed range is no greater than T·1000 / (14·N) nanoseconds, wherein T is a time slot size in microseconds μs, and wherein the PRS configuration is comb-N.

44. The method of claim 37, wherein: A different RSTD search window is determined for each frequency range associated with the PRS configuration.

45. The method of claim 37, wherein: The resolution value of the RSTD search window is K·T c 2 u , where T c =1 / (480,000·4096), and wherein K={1,2,3} and u={1,2,3,4,5,6}.

46. ​​The method of claim 45, wherein: The selected value of K or u is based on the parameter set of the PRS configuration.

47. The method of claim 46, wherein: Based on a numerology set with 15 kHz subcarrier spacing, K=3 and u=6.

48. The method of claim 46, wherein: For any parameter set with subcarrier spacing greater than 15 kHz, K is selected from the integers 1, 2, or 3, and u is less than 6.

49. The method of claim 45, wherein: The selected value of K or u is configured.

50. The method of claim 45, wherein: The expected RSTD parameter uses a granularity 14 bits to encode, where u1 = {1, 2, 3, 4, 5, 6}, and T c It is 0.509 nanoseconds.

51. The method of claim 45, wherein: The RSTD uncertainty parameters are given using a granularity 10 bits to encode, where u2 = {1, 2, 3, 4, 5, 6}, and T c It is 0.509 nanoseconds.

52. The method of claim 51, wherein: u1 and u2 are different.

53. The method of claim 37, wherein: Receiving the RSTD search window further includes: A plurality of RSTD search windows having a plurality of allowed ranges are received.

54. The method of claim 53, wherein: At least one of the plurality of RSTD search windows is associated with a resolution.

55. The method of claim 53, further comprising: Which of the plurality of RSTD search windows applies to a PRS configuration, a PRS opportunity, a PRS instance, or a PRS opportunity group is received.

56. The method of claim 55, wherein: The UE is signaled using downlink control information DCI or medium access control MAC control element CE.

57. The method of claim 53, further comprising: A report is sent to the network node reporting the RSTD determined for the plurality of RSTD search windows.

58. The method of claim 53, wherein: A different one of the plurality of RSTD search windows is configured for each frequency band on which the UE is expected to measure the plurality of PRSs.

59. The method of claim 53, wherein: A different one of the plurality of RSTD search windows is configured for each frequency range in which the UE is expected to measure the plurality of PRSs.

60. The method of claim 37, wherein: The PRS configuration is an aperiodic PRS or a semi-persistent PRS.

61. The method of claim 37, wherein: The network node is not sufficiently synchronized with a serving base station of the UE, and wherein the RSTD search window is referenced to an alternative base station that is sufficiently synchronized with the network node.

62. The method of claim 61, further comprising performing a Physical Random Access Channel (PRACH) procedure with the alternative base station.

63. The method of claim 37, wherein: The network node is a base station.

64. The method of claim 63, wherein: Receiving includes receiving the RSTD search window from a location server via the base station.

65. The method of claim 37, wherein: The RSTD search window is received as part of downlink positioning reference signal assistance information, and The size of the RSTD search window is received in the downlink positioning reference signal auxiliary information as the number of one or more orthogonal frequency division multiplexing OFDM symbols.

66. The method of claim 65, wherein: The number of the one or more OFDM symbols is based on a frequency range in which the UE is expected to measure the plurality of PRSs.

67. The method of claim 65, wherein: Each of the following is represented by a number of one or more OFDM symbols: the search window offset per cell per opportunity parameter, the search window size per cell per opportunity parameter, and the complete search range for all cells per positioning session parameter.

68. The method of claim 37, further comprising: The RSTD is reported to a network entity.

69. The method of claim 68, wherein: The network entity is a base station or a location server.

70. The method of claim 37, further comprising: The location of the UE is determined at the UE using the RSTD.

71. The method of claim 37, wherein: The network node and the reference node are each one of a base station, an access point, or a transmission point belonging to the same base station.

72. The method of claim 37, wherein: The frequency range of the plurality of PRSs is FR1, the range of FR1 is from 450 MHz to 6000 MHz, and The value of the RSTD uncertainty parameter is + / - 32 microseconds.

73. The method of claim 37, wherein: The frequency range of the plurality of PRSs is FR2, the range of FR2 is from 24250 MHz to 52600 MHz, and The value of the RSTD uncertainty parameter is + / - 8 microseconds.

74. A method of operating a location server, comprising: determining a reference signal timing difference (RSTD) search window based on a positioning reference signal (PRS) configuration, wherein the RSTD search window is defined by an expected RSTD parameter and an RSTD uncertainty parameter, wherein the RSTD search window has an allowed range based on the PRS configuration, and wherein a different size of the RSTD search window is determined for each frequency range associated with the PRS configuration; providing the RSTD search window to a user equipment UE via a base station serving the UE; and A plurality of PRSs defined by the PRS configuration are configured to be transmitted to the UE, wherein the plurality of PRSs are to be transmitted in a subset of subcarriers that is less than all subcarriers over a given bandwidth.

75. The method of claim 74, wherein: The allowed range of the comb-N PRS configuration is greater than the allowed range of the comb-M PRS configuration, and wherein N is less than M.

76. The method of claim 75, wherein: N is greater than 1.

77. The method of claim 74, wherein: The allowed range is inversely proportional to a Comb-N PRS configuration without frequency interleaving.

78. The method of claim 74, wherein: The allowable range is on the order of nanoseconds ns.

79. The method of claim 74, wherein: The allowed range is based on a parameter set of the PRS configuration.

80. The method of claim 79, wherein: The allowed range is no greater than T·1000 / (14·N) nanoseconds, wherein T is a time slot size in microseconds μs, and wherein the PRS configuration is comb-N.

81. The method of claim 74, wherein: Determining the RSTD search window based on the PRS configuration includes: A different RSTD search window is determined for each frequency range associated with the PRS configuration.

82. The method of claim 74, wherein: The resolution value of the RSTD search window is K·T c 2 u , where T c =1 / (480,000·4096), and wherein K={1,2,3} and u={1,2,3,4,5,6}.

83. The method of claim 82, wherein: The selected value of K or u is based on the parameter set of the PRS configuration.

84. The method of claim 83, wherein: Based on a numerology set with 15 kHz subcarrier spacing, K=3 and u=6.

85. The method of claim 83, wherein: For any parameter set with subcarrier spacing greater than 15 kHz, K is selected from the integers 1, 2, or 3, and u is less than 6.

86. The method of claim 82, wherein: The selected value of K or u is configured.

87. The method of claim 82, wherein the expected RSTD parameter uses a The 14 bits are used to encode, where u1={1,2,3,4,5,6}, and T c It is 0.509 nanoseconds.

88. The method of claim 87, wherein: The RSTD uncertainty parameters are given using a granularity 10 bits to encode, where u2 = {1, 2, 3, 4, 5, 6}, and T c It is 0.509 nanoseconds.

89. The method of claim 88, wherein: u1 and u2 are different.

90. The method of claim 74, wherein: Providing the RSTD search window also includes: configuring multiple allowed ranges for multiple RSTD search windows; and The plurality of RSTD search windows having the plurality of allowed ranges are provided to the UE via the base station.

91. The method of claim 90, wherein: At least one of the plurality of RSTD search windows is associated with a resolution.

92. The method of claim 90, further comprising: The UE is signaled which of the multiple RSTD search windows applies to a PRS configuration, a PRS opportunity, a PRS instance, or a PRS opportunity group.

93. The method of claim 92, wherein: The UE is signaled using downlink control information DCI or medium access control MAC control element CE.

94. The method of claim 90, further comprising: A report is received from the UE reporting the RSTD determined for the plurality of RSTD search windows.

95. The method of claim 90, wherein: A different one of the plurality of RSTD search windows is configured for each frequency band on which the UE is expected to measure the plurality of PRSs.

96. The method of claim 90, wherein: A different one of the plurality of RSTD search windows is configured for each frequency range in which the UE is expected to measure the plurality of PRSs.

97. The method of claim 74, wherein: The PRS configuration is an aperiodic PRS or a semi-persistent PRS.

98. The method of claim 74, further comprising: A position estimate of the UE is obtained, wherein the accuracy of the position estimate is less than aliased repetitions produced by a Comb-N PRS configuration.

99. The method of claim 98, wherein: The position estimate of the UE is obtained while tracking the UE.

100. The method of claim 74, wherein: The RSTD search window is provided as part of the downlink positioning reference signal assistance information, and The size of the RSTD search window is provided in the downlink positioning reference signal auxiliary information as the number of one or more orthogonal frequency division multiplexing OFDM symbols.

101. The method according to claim 100, wherein: The number of the one or more OFDM symbols is based on a frequency range in which the UE is expected to measure the plurality of PRSs.

102. The method of claim 100, wherein: Each of the following is represented by a number of one or more OFDM symbols: the search window offset per cell per opportunity parameter, the search window size per cell per opportunity parameter, and the complete search range for all cells per positioning session parameter.

103. The method of claim 74, wherein: The frequency range of the plurality of PRSs is FR1, the range of FR1 is from 450 MHz to 6000 MHz, and The value of the RSTD uncertainty parameter is + / - 32 microseconds.

104. The method of claim 74, wherein: The frequency range of the plurality of PRSs is FR2, the range of FR2 is from 24250 MHz to 52600 MHz, and The value of the RSTD uncertainty parameter is + / - 8 microseconds.

105. A network entity comprising: transceiver circuit; Memory circuit; as well as a processor circuit communicatively coupled to the transceiver circuit and the memory circuit, Wherein, the processor circuit is configured as: obtaining a reference signal timing difference (RSTD) search window based on a positioning reference signal (PRS) configuration, wherein the RSTD search window is defined by an expected RSTD parameter and an RSTD uncertainty parameter, wherein the RSTD search window has an allowed range based on the PRS configuration, and wherein a different size of the RSTD search window is determined for each frequency range associated with the PRS configuration; providing the RSTD search window to a user equipment UE; and A plurality of PRSs defined by the PRS configuration are transmitted to the UE, wherein the plurality of PRSs are transmitted in a subset of subcarriers that is less than all subcarriers over a given bandwidth.

106. A network entity comprising: means for obtaining a reference signal timing difference (RSTD) search window based on a positioning reference signal (PRS) configuration, wherein the RSTD search window is defined by an expected RSTD parameter and an RSTD uncertainty parameter, wherein the RSTD search window has an allowed range based on the PRS configuration, and wherein a different size of the RSTD search window is determined for each frequency range associated with the PRS configuration; A component for providing the RSTD search window to a user equipment UE; as well as Means for transmitting a plurality of PRSs defined by the PRS configuration to the UE, wherein the plurality of PRSs are transmitted in a subset of the subcarriers that is less than all subcarriers over a given bandwidth.

107. A non-transitory computer-readable medium storing computer-executable instructions for a network entity, the computer-executable instructions comprising: one or more instructions instructing the network entity to obtain a reference signal timing difference (RSTD) search window based on a positioning reference signal (PRS) configuration, wherein the RSTD search window is defined by an expected RSTD parameter and an RSTD uncertainty parameter, wherein the RSTD search window has an allowed range based on the PRS configuration, and wherein a different size of the RSTD search window is determined for each frequency range associated with the PRS configuration; Instructing the network entity to provide one or more instructions of the RSTD search window to a user equipment UE; as well as One or more instructions instructing the network entity to send a plurality of PRSs defined by the PRS configuration to the UE, wherein the plurality of PRSs are sent in a subset of subcarriers that is less than all subcarriers over a given bandwidth.

108. A user equipment UE, comprising: transceiver circuit; Memory circuit; as well as a processor circuit communicatively coupled to the transceiver circuit and the memory circuit, Wherein, the processor circuit is configured as: receiving a reference signal timing difference (RSTD) search window based on a positioning reference signal (PRS) configuration, wherein the RSTD search window is defined by an expected RSTD parameter and an RSTD uncertainty parameter, wherein the RSTD search window has an allowed range based on the PRS configuration, and wherein a different size of the RSTD search window is determined for each frequency range associated with the PRS configuration; receiving, from a network node, a plurality of PRSs defined by the PRS configuration, wherein the plurality of PRSs are transmitted in a subset of subcarriers that is less than all subcarriers over a given bandwidth; and An RSTD between the network node and a reference node is determined based on the RSTD search window.

109. A user equipment UE, comprising: means for receiving a reference signal timing difference (RSTD) search window based on a positioning reference signal (PRS) configuration, wherein the RSTD search window is defined by an expected RSTD parameter and an RSTD uncertainty parameter, wherein the RSTD search window has an allowed range based on the PRS configuration, and wherein a different size of the RSTD search window is determined for each frequency range associated with the PRS configuration; means for receiving, from a network node, a plurality of PRSs defined by the PRS configuration, wherein the plurality of PRSs are transmitted in a subset of subcarriers that is less than all subcarriers over a given bandwidth; as well as Means for determining an RSTD between the network node and a reference node based on the RSTD search window.

110. A non-transitory computer-readable medium storing computer-executable instructions for a user equipment (UE), the computer-executable instructions comprising: one or more instructions instructing the UE to receive a reference signal timing difference (RSTD) search window based on a positioning reference signal (PRS) configuration, wherein the RSTD search window is defined by an expected RSTD parameter and an RSTD uncertainty parameter, wherein the RSTD search window has an allowed range based on the PRS configuration, and wherein a different size of the RSTD search window is determined for each frequency range associated with the PRS configuration; instructing the UE to receive one or more instructions from a network node for a plurality of PRSs defined by the PRS configuration, wherein the plurality of PRSs are transmitted in a subset of subcarriers that is less than all subcarriers over a given bandwidth; and One or more instructions instructing the UE to determine the RSTD between the network node and a reference node based on the RSTD search window.

111. A location server comprising: transceiver circuit; Memory circuit; as well as a processor circuit communicatively coupled to the transceiver circuit and the memory circuit, Wherein, the transceiver circuit, the memory circuit and the processor circuit are configured as follows: determining a reference signal timing difference (RSTD) search window based on a positioning reference signal (PRS) configuration, wherein the RSTD search window is defined by an expected RSTD parameter and an RSTD uncertainty parameter, wherein the RSTD search window has an allowed range based on the PRS configuration, and wherein a different size of the RSTD search window is determined for each frequency range associated with the PRS configuration; providing the RSTD search window to a user equipment UE or a base station serving the UE; and A plurality of PRSs defined by the PRS configuration are configured to be transmitted to the UE, wherein the plurality of PRSs are to be transmitted in a subset of subcarriers that is less than all subcarriers over a given bandwidth.

112. A location server comprising: means for determining a reference signal timing difference (RSTD) search window based on a positioning reference signal (PRS) configuration, wherein the RSTD search window is defined by an expected RSTD parameter and an RSTD uncertainty parameter, wherein the RSTD search window has an allowed range based on the PRS configuration, and wherein a different size of the RSTD search window is determined for each frequency range associated with the PRS configuration; A component for providing the RSTD search window to a user equipment UE or a base station serving the UE; as well as Means for configuring a plurality of PRSs defined by the PRS configuration to be transmitted to the UE, wherein the plurality of PRSs are to be transmitted in a subset of subcarriers that is less than all subcarriers over a given bandwidth.

113. A non-transitory computer-readable medium storing computer-executable instructions for a location server, the computer-executable instructions comprising: one or more instructions instructing the location server to determine a reference signal timing difference (RSTD) search window based on a positioning reference signal (PRS) configuration, wherein the RSTD search window is defined by an expected RSTD parameter and an RSTD uncertainty parameter, wherein the RSTD search window has an allowed range based on the PRS configuration, and wherein a different size of the RSTD search window is determined for each frequency range associated with the PRS configuration; Instructing the location server to provide one or more instructions of the RSTD search window to a user equipment UE or a base station serving the UE; as well as One or more instructions instructing the location server to configure a plurality of PRSs defined by the PRS configuration to be sent to the UE, wherein the plurality of PRSs are to be sent in a subset of subcarriers that is less than all subcarriers over a given bandwidth.

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