Patent Description:
Aspects of the disclosure relate generally to wireless communications.

Wireless communication systems have developed through various generations, including a first-generation analog wireless phone service (<NUM>), a second-generation (<NUM>) digital wireless phone service (including interim <NUM> networks), a third-generation (<NUM>) high speed data, Internet-capable wireless service and a fourth-generation (<NUM>) service (e.g., LTE or WiMax). There are presently many different types of wireless communication systems in use, including cellular and personal communications service (PCS) systems. Examples of known cellular systems include the cellular Analog Advanced Mobile Phone System (AMPS), and digital cellular systems based on code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), the Global System for Mobile communication (GSM), etc..

A fifth generation (<NUM>) wireless standard, also referred to as New Radio (NR), enables higher data transfer speeds, greater numbers of connections, and better coverage, among other improvements. The <NUM> standard, according to the Next Generation Mobile Networks Alliance, is designed to provide data rates of several tens of megabits per second to each of tens of thousands of users, with <NUM> gigabit per second to tens of workers on an office floor. Several hundreds of thousands of simultaneous connections should be supported in order to support large wireless deployments. Consequently, the spectral efficiency of <NUM> mobile communications should be significantly enhanced compared to the current <NUM> standard. Furthermore, signaling efficiencies should be enhanced and latency should be substantially reduced compared to current standards.

Document 3GPP, R1-<NUM> relates to UE & gNB measurements for NR Positioning. Document <CIT> discloses providing a processing delay estimate of an access point, or turnaround calibration function (TCF), associated with round trip time (RTT) measurements.

Document 3GPP, R1-<NUM> relates UE and gNB measurements for NR Positioning.

The invention is defined in independent claims. Dependent claims concern particular embodiments of the invention. Any subject matter presented in the description but not falling under the claims constitutes an aspect of the disclosure which may be useful for understanding the invention.

The following presents a simplified summary relating to one or more aspects disclosed herein. Thus, the following summary should not be considered an extensive overview relating to all contemplated aspects, nor should the following summary be considered to identify key or critical elements relating to all contemplated aspects or to delineate the scope associated with any particular aspect. Accordingly, the following summary has the sole purpose to present certain concepts relating to one or more aspects relating to the mechanisms disclosed herein in a simplified form to precede the detailed description presented below.

As used herein, the terms "user equipment" (UE) and "base station" are not intended to be specific or otherwise limited to any particular radio access technology (RAT), unless otherwise noted. In general, a UE may be any wireless communication device (e.g., a mobile phone, router, tablet computer, laptop computer, tracking device, wearable (e.g., smartwatch, glasses, augmented reality (AR) / virtual reality (VR) headset, etc.), vehicle (e.g., automobile, motorcycle, bicycle, etc.), Internet of Things (IoT) device, etc.) used by a user to communicate over a wireless communications network. A UE may be mobile or may (e.g., at certain times) be stationary, and may communicate with a radio access network (RAN). As used herein, the term "UE" may be referred to interchangeably as an "access terminal" or "AT," a "client device," a "wireless device," a "subscriber device," a "subscriber terminal," a "subscriber station," a "user terminal" or UT, a "mobile device," a "mobile terminal," a "mobile station," or variations thereof. Generally, UEs can communicate with a core network via a RAN, and through the core network the UEs can be connected with external networks such as the Internet and with other UEs. Of course, other mechanisms of connecting to the core network and/or the Internet are also possible for the UEs, such as over wired access networks, wireless local area network (WLAN) networks (e.g., based on IEEE <NUM>, etc.) and so on.

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

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

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

An "RF signal" comprises an electromagnetic wave of a given frequency that transports 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, the receiver may receive multiple "RF signals" corresponding to each transmitted RF signal due to the propagation characteristics of RF signals through multipath channels. The same transmitted RF signal on different paths between the transmitter and receiver may be referred to as a "multipath" RF signal. As used herein, an RF signal may also be referred to as a "wireless signal" or simply a "signal" where it is clear from the context that the term "signal" refers to a wireless signal or an RF signal.

According to various aspects, <FIG> illustrates an exemplary wireless communications system <NUM>. The wireless communications system <NUM> (which may also be referred to as a wireless wide area network (WWAN)) may include various base stations <NUM> and various UEs <NUM>. The base stations <NUM> may include macro cell base stations (high power cellular base stations) and/or small cell base stations (low power cellular base stations). In an aspect, the macro cell base station may include eNBs and/or ng-eNBs where the wireless communications system <NUM> corresponds to an LTE network, or gNBs where the wireless communications system <NUM> corresponds to a NR network, or a combination of both, and the small cell base stations may include femtocells, picocells, microcells, etc..

The base stations <NUM> may collectively form a RAN and interface with a core network <NUM> (e.g., an evolved packet core (EPC) or a <NUM> core (5GC)) through backhaul links <NUM>, and through the core network <NUM> to one or more location servers <NUM> (which may be part of core network <NUM> or may be external to core network <NUM>). In addition to other functions, the base stations <NUM> may perform functions that relate to one or more of transferring user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations <NUM> may communicate with each other directly or indirectly (e.g., through the EPC / 5GC) over backhaul links <NUM>, which may be wired or wireless.

In an aspect, one or more cells may be supported by a base station <NUM> in each geographic coverage area <NUM>. A "cell" is a logical communication entity used for communication with a base station (e.g., over some frequency resource, referred to as a carrier frequency, component carrier, carrier, band, or the like), and may be associated with an identifier (e.g., a physical cell identifier (PCI), a virtual cell identifier (VCI), a cell global identifier (CGI)) for distinguishing cells operating via the same or a different carrier frequency. In some cases, different cells may be configured according to different protocol types (e.g., machine-type communication (MTC), narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB), or others) that may provide access for different types of UEs. Because a cell is supported by a specific base station, the term "cell" may refer to either or both of the logical communication entity and the base station that supports it, depending on the context. In addition, because a TRP is typically the physical transmission point of a cell, the terms "cell" and "TRP" may be used interchangeably. In some cases, the term "cell" may also refer to a geographic coverage area of a base station (e.g., a sector), insofar as a carrier frequency can be detected and used for communication within some portion of geographic coverage areas <NUM>.

While neighboring macro cell base station <NUM> geographic coverage areas <NUM> may partially overlap (e.g., in a handover region), some of the geographic coverage areas <NUM> may be substantially overlapped by a larger geographic coverage area <NUM>. For example, a small cell base station <NUM>' may have a coverage area <NUM>' that substantially overlaps with the geographic coverage area <NUM> of one or more macro cell base stations <NUM>. A network that includes both small cell and macro cell base stations may be known as a heterogeneous network. A heterogeneous network may also include home eNBs (HeNBs), which may provide service to a restricted group known as a closed subscriber group (CSG).

The communication links <NUM> between the base stations <NUM> and the UEs <NUM> may include uplink (also referred to as reverse link) transmissions from a UE <NUM> to a base station <NUM> and/or downlink (also referred to as forward link) transmissions from a base station <NUM> to a UE <NUM>. The communication links <NUM> may use MIMO antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links <NUM> may be through one or more carrier frequencies. Allocation of carriers may be asymmetric with respect to downlink and uplink (e.g., more or less carriers may be allocated for downlink than for uplink).

Specifically, the RF current from the transmitter is fed to the individual antennas with the correct phase relationship so that the radio waves from the separate antennas add together to increase the radiation in a desired direction, while canceling to suppress radiation in undesired directions.

Receive beams may be spatially related. A spatial relation means that parameters for a transmit beam for a second reference signal can be derived from information about a receive beam for a first reference signal. For example, a UE may use a particular receive beam to receive one or more reference downlink reference signals (e.g., positioning reference signals (PRS), navigation reference signals (NRS), tracking reference signals (TRS), phase tracking reference signal (PTRS), cell-specific reference signals (CRS), channel state information reference signals (CSI-RS), primary synchronization signals (PSS), secondary synchronization signals (SSS), synchronization signal blocks (SSBs), etc.) from a base station. The UE can then form a transmit beam for sending one or more uplink reference signals (e.g., uplink positioning reference signals (UL-PRS), sounding reference signal (SRS), demodulation reference signals (DMRS), PTRS, etc.) to that base station based on the parameters of the receive beam.

In <NUM>, the frequency spectrum in which wireless nodes (e.g., base stations <NUM>/<NUM>, UEs <NUM>/<NUM>) operate is divided into multiple frequency ranges, FR1 (from <NUM> to <NUM>), FR2 (from <NUM> to <NUM>), FR3 (above <NUM>), and FR4 (between FR1 and FR2). In a multi-carrier system, such as <NUM>, one of the carrier frequencies is referred to as the "primary carrier" or "anchor carrier" or "primary serving cell" or "PCell," and the remaining carrier frequencies are referred to as "secondary carriers" or "secondary serving cells" or "SCells. " In carrier aggregation, the anchor carrier is the carrier operating on the primary frequency (e.g., FR1) utilized by a UE <NUM>/<NUM> and the cell in which the UE <NUM>/<NUM> either performs the initial radio resource control (RRC) connection establishment procedure or initiates the RRC connection re-establishment procedure. The primary carrier carries all common and UE-specific control channels, and may 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 may be configured once the RRC connection is established between the UE <NUM> and the anchor carrier and that may 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, those that are UE-specific may not be present in the secondary carrier, since both primary uplink and downlink carriers are typically UE-specific. This means that different UEs <NUM>/<NUM> in a cell may have different downlink primary carriers. The same is true for the uplink primary carriers. The network is able to change the primary carrier of any UE <NUM>/<NUM> at any time. This is done, for example, to balance the load on different carriers. Because a "serving cell" (whether a PCell or an SCell) corresponds to a carrier frequency / component carrier over which some base station is communicating, the term "cell," "serving cell," "component carrier," "carrier frequency," and the like can be used interchangeably.

The wireless communications system <NUM> may further include one or more UEs, such as UE <NUM>, that connects indirectly to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links. In the example of <FIG>, UE <NUM> has a D2D P2P link <NUM> with one of the UEs <NUM> connected to one of the base stations <NUM> (e.g., through which UE <NUM> may indirectly obtain cellular connectivity) and a D2D P2P link <NUM> with WLAN STA <NUM> connected to the WLAN AP <NUM> (through which UE <NUM> may indirectly obtain WLAN-based Internet connectivity). In an example, the D2D P2P links <NUM> and <NUM> may be supported with any well-known D2D RAT, such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), Bluetooth®, and so on.

The wireless communications system <NUM> may further include a UE <NUM> that may communicate with a macro cell base station <NUM> over a communication link <NUM> and/or the mmW base station <NUM> over a mmW communication link <NUM>. For example, the macro cell base station <NUM> may support a PCell and one or more SCells for the UE <NUM> and the mmW base station <NUM> may support one or more SCells for the UE <NUM>.

According to various aspects, <FIG> illustrates an example wireless network structure <NUM>. For example, a 5GC <NUM> (also referred to as a Next Generation Core (NGC)) can be viewed functionally as control plane functions <NUM> (e.g., UE registration, authentication, network access, gateway selection, etc.) and user plane functions <NUM>, (e.g., UE gateway function, access to data networks, IP routing, etc.) which operate cooperatively to form the core network. User plane interface (NG-U) <NUM> and control plane interface (NG-C) <NUM> connect the gNB <NUM> to the 5GC <NUM> and specifically to the control plane functions <NUM> and user plane functions <NUM>. In an additional configuration, an ng-eNB <NUM> may also be connected to the 5GC <NUM> via NG-C <NUM> to the control plane functions <NUM> and NG-U <NUM> to user plane functions <NUM>. Further, ng-eNB <NUM> may directly communicate with gNB <NUM> via a backhaul connection <NUM>. In some configurations, the New RAN <NUM> may only have one or more gNBs <NUM>, while other configurations include one or more of both ng-eNBs <NUM> and gNBs <NUM>. Either gNB <NUM> or ng-eNB <NUM> may communicate with UEs <NUM> (e.g., any of the UEs depicted in <FIG>). Another optional aspect may include location server <NUM>, which may be in communication with the 5GC <NUM> to provide location assistance for UEs <NUM>. The location server <NUM> can be implemented as a plurality of separate servers (e.g., physically separate servers, different software modules on a single server, different software modules spread across multiple physical servers, etc.), or alternately may each correspond to a single server. The location server <NUM> can be configured to support one or more location services for UEs <NUM> that can connect to the location server <NUM> via the core network, 5GC <NUM>, and/or via the Internet (not illustrated). Further, the location server <NUM> may be integrated into a component of the core network, or alternatively may be external to the core network.

According to various aspects, <FIG> illustrates another example wireless network structure <NUM>. For example, a 5GC <NUM> can be viewed functionally as control plane functions, provided by an access and mobility management function (AMF) <NUM>, and user plane functions, provided by a user plane function (UPF) <NUM>, which operate cooperatively to form the core network (i.e., 5GC <NUM>). User plane interface <NUM> and control plane interface <NUM> connect the ng-eNB <NUM> to the 5GC <NUM> and specifically to UPF <NUM> and AMF <NUM>, respectively. In an additional configuration, a gNB <NUM> may also be connected to the 5GC <NUM> via control plane interface <NUM> to AMF <NUM> and user plane interface <NUM> to UPF <NUM>. Further, ng-eNB <NUM> may directly communicate with gNB <NUM> via the backhaul connection <NUM>, with or without gNB direct connectivity to the 5GC <NUM>. In some configurations, the New RAN <NUM> may only have one or more gNBs <NUM>, while other configurations include one or more of both ng-eNBs <NUM> and gNBs <NUM>. Either gNB <NUM> or ng-eNB <NUM> may communicate with UEs <NUM> (e.g., any of the UEs depicted in <FIG>). The base stations of the New RAN <NUM> communicate with the AMF <NUM> over the N2 interface and with the UPF <NUM> over the N3 interface.

The functions of the AMF <NUM> include registration management, connection management, reachability management, mobility management, lawful interception, transport for session management (SM) messages between the UE <NUM> and a session management function (SMF) <NUM>, transparent proxy services for routing SM messages, access authentication and access authorization, transport for short message service (SMS) messages between the UE <NUM> and the short message service function (SMSF) (not shown), and security anchor functionality (SEAF). The AMF <NUM> also interacts with an authentication server function (AUSF) (not shown) and the UE <NUM>, and receives the intermediate key that was established as a result of the UE <NUM> authentication process. In the case of authentication based on a UMTS (universal mobile telecommunications system) subscriber identity module (USIM), the AMF <NUM> retrieves the security material from the AUSF. The functions of the AMF <NUM> also include security context management (SCM). The SCM receives a key from the SEAF that it uses to derive access-network specific keys. The functionality of the AMF <NUM> also includes location services management for regulatory services, transport for location services messages between the UE <NUM> and a location management function (LMF) <NUM> (which acts as a location server <NUM>), transport for location services messages between the New RAN <NUM> and the LMF <NUM>, evolved packet system (EPS) bearer identifier allocation for interworking with the EPS, and UE <NUM> mobility event notification. In addition, the AMF <NUM> also supports functionalities for non-3GPP access networks.

Functions of the UPF <NUM> include acting as an anchor point for intra-/inter-RAT mobility (when applicable), acting as an external protocol data unit (PDU) session point of interconnect to a data network (not shown), providing packet routing and forwarding, packet inspection, user plane policy rule enforcement (e.g., gating, redirection, traffic steering), lawful interception (user plane collection), traffic usage reporting, quality of service (QoS) handling for the user plane (e.g., uplink/downlink rate enforcement, reflective QoS marking in the downlink), uplink traffic verification (service data flow (SDF) to QoS flow mapping), transport level packet marking in the uplink and downlink, downlink packet buffering and downlink data notification triggering, and sending and forwarding of one or more "end markers" to the source RAN node. The UPF <NUM> may also support transfer of location services messages over a user plane between the UE <NUM> and a location server, such as a secure user plane location (SUPL) location platform (SLP) <NUM>.

The functions of the SMF <NUM> include session management, UE Internet protocol (IP) address allocation and management, selection and control of user plane functions, configuration of traffic steering at the UPF <NUM> to route traffic to the proper destination, control of part of policy enforcement and QoS, and downlink data notification. The interface over which the SMF <NUM> communicates with the AMF <NUM> is referred to as the N11 interface.

Another optional aspect may include an LMF <NUM>, which may be in communication with the 5GC <NUM> to provide location assistance for UEs <NUM>. The LMF <NUM> can be implemented as a plurality of separate servers (e.g., physically separate servers, different software modules on a single server, different software modules spread across multiple physical servers, etc.), or alternately may each correspond to a single server. The LMF <NUM> can be configured to support one or more location services for UEs <NUM> that can connect to the LMF <NUM> via the core network, 5GC <NUM>, and/or via the Internet (not illustrated). The SLP <NUM> may support similar functions to the LMF <NUM>, but whereas the LMF <NUM> may communicate with the AMF <NUM>, New RAN <NUM>, and UEs <NUM> over a control plane (e.g., using interfaces and protocols intended to convey signaling messages and not voice or data), the SLP <NUM> may communicate with UEs <NUM> and external clients (not shown in <FIG>) over a user plane (e.g., using protocols intended to carry voice and/or data like the transmission control protocol (TCP) and/or IP).

<FIG>, <FIG>, and <FIG> illustrate several exemplary components (represented by corresponding blocks) that may be incorporated into a UE <NUM> (which may correspond to any of the UEs described herein), a base station <NUM> (which may correspond to any of the base stations described herein), and a network entity <NUM> (which may correspond to or embody any of the network functions described herein, including the location server <NUM>, the LMF <NUM>, and the SLP <NUM>) to support the file transmission operations as taught herein. It will be appreciated that these components may be implemented in different types of apparatuses in different implementations (e.g., in an ASIC, in a system-on-chip (SoC), etc.). The illustrated components may also be incorporated into other apparatuses in a communication system. For example, other apparatuses in a system may include components similar to those described to provide similar functionality. Also, a given apparatus may contain one or more of the components. For example, an apparatus may include multiple transceiver components that enable the apparatus to operate on multiple carriers and/or communicate via different technologies.

The UE <NUM> and the base station <NUM> each include wireless wide area network (WWAN) transceiver <NUM> and <NUM>, respectively, configured to communicate via one or more wireless communication networks (not shown), such as an NR network, an LTE network, a GSM network, and/or the like. The WWAN transceivers <NUM> and <NUM> may be connected to one or more antennas <NUM> and <NUM>, respectively, for communicating with other network nodes, such as other UEs, access points, base stations (e.g., ng-eNBs, gNBs), etc., via at least one designated RAT (e.g., NR, LTE, GSM, etc.) over a wireless communication medium of interest (e.g., some set of time/frequency resources in a particular frequency spectrum). The WWAN transceivers <NUM> and <NUM> may be variously configured for transmitting and encoding signals <NUM> and <NUM> (e.g., messages, indications, information, and so on), respectively, and, conversely, for receiving and decoding signals <NUM> and <NUM> (e.g., messages, indications, information, pilots, and so on), respectively, in accordance with the designated RAT. Specifically, the WWAN transceivers <NUM> and <NUM> include one or more transmitters <NUM> and <NUM>, respectively, for transmitting and encoding signals <NUM> and <NUM>, respectively, and one or more receivers <NUM> and <NUM>, respectively, for receiving and decoding signals <NUM> and <NUM>, respectively.

The UE <NUM> and the base station <NUM> also include, at least in some cases, wireless local area network (WLAN) transceivers <NUM> and <NUM>, respectively. The WLAN transceivers <NUM> and <NUM> may be connected to one or more antennas <NUM> and <NUM>, respectively, for communicating with other network nodes, such as other UEs, access points, base stations, etc., via at least one designated RAT (e.g., WiFi, LTE-D, Bluetooth®, etc.) over a wireless communication medium of interest. The WLAN transceivers <NUM> and <NUM> may be variously configured for transmitting and encoding signals <NUM> and <NUM> (e.g., messages, indications, information, and so on), respectively, and, conversely, for receiving and decoding signals <NUM> and <NUM> (e.g., messages, indications, information, pilots, and so on), respectively, in accordance with the designated RAT. Specifically, the WLAN transceivers <NUM> and <NUM> include one or more transmitters <NUM> and <NUM>, respectively, for transmitting and encoding signals <NUM> and <NUM>, respectively, and one or more receivers <NUM> and <NUM>, respectively, for receiving and decoding signals <NUM> and <NUM>, respectively.

Transceiver circuitry including at least one transmitter and at least one receiver may comprise an integrated device (e.g., embodied as a transmitter circuit and a receiver circuit of a single communication device) in some implementations, may comprise a separate transmitter device and a separate receiver device in some implementations, or may be embodied in other ways in other implementations. In an aspect, a transmitter may include or be coupled to a plurality of antennas (e.g., antennas <NUM>, <NUM>, <NUM>, <NUM>), such as an antenna array, that permits the respective apparatus to perform transmit "beamforming," as described herein. Similarly, a receiver may include or be coupled to a plurality of antennas (e.g., antennas <NUM>, <NUM>, <NUM>, <NUM>), such as an antenna array, that permits the respective apparatus to perform receive beamforming, as described herein. In an aspect, the transmitter and receiver may share the same plurality of antennas (e.g., antennas <NUM>, <NUM>, <NUM>, <NUM>), such that the respective apparatus can only receive or transmit at a given time, not both at the same time. A wireless communication device (e.g., one or both of the transceivers <NUM> and <NUM> and/or <NUM> and <NUM>) of the UE <NUM> and/or the base station <NUM> may also comprise a network listen module (NLM) or the like for performing various measurements.

The UE <NUM> and the base station <NUM> also include, at least in some cases, satellite positioning systems (SPS) receivers <NUM> and <NUM>. The SPS receivers <NUM> and <NUM> may be connected to one or more antennas <NUM> and <NUM>, respectively, for receiving SPS signals <NUM> and <NUM>, respectively, such as global positioning system (GPS) signals, global navigation satellite system (GLONASS) signals, Galileo signals, Beidou signals, Indian Regional Navigation Satellite System (NAVIC), Quasi-Zenith Satellite System (QZSS), etc. The SPS receivers <NUM> and <NUM> may comprise any suitable hardware and/or software for receiving and processing SPS signals <NUM> and <NUM>, respectively. The SPS receivers <NUM> and <NUM> request information and operations as appropriate from the other systems, and performs calculations necessary to determine positions of the UE <NUM> and the base station <NUM> using measurements obtained by any suitable SPS algorithm.

The base station <NUM> and the network entity <NUM> each include at least one network interfaces <NUM> and <NUM> for communicating with other network entities. For example, the network interfaces <NUM> and <NUM> (e.g., one or more network access ports) may be configured to communicate with one or more network entities via a wire-based or wireless backhaul connection. In some aspects, the network interfaces <NUM> and <NUM> may be implemented as transceivers configured to support wire-based or wireless signal communication. This communication may involve, for example, sending and receiving messages, parameters, and/or other types of information.

The UE <NUM>, the base station <NUM>, and the network entity <NUM> also include other components that may be used in conjunction with the operations as disclosed herein. The UE <NUM> includes processor circuitry implementing a processing system <NUM> for providing functionality relating to, for example, positioning operations, and for providing other processing functionality. The base station <NUM> includes a processing system <NUM> for providing functionality relating to, for example, positioning operations as disclosed herein, and for providing other processing functionality. The network entity <NUM> includes a processing system <NUM> for providing functionality relating to, for example, positioning operations as disclosed herein, and for providing other processing functionality. In an aspect, the processing systems <NUM>, <NUM>, and <NUM> may include, for example, one or more general purpose processors, multi-core processors, ASICs, digital signal processors (DSPs), field programmable gate arrays (FPGA), or other programmable logic devices or processing circuitry.

The UE <NUM>, the base station <NUM>, and the network entity <NUM> include memory circuitry implementing memory components <NUM>, <NUM>, and <NUM> (e.g., each including a memory device), respectively, for maintaining information (e.g., information indicative of reserved resources, thresholds, parameters, and so on). In some cases, the UE <NUM>, the base station <NUM>, and the network entity <NUM> may include positioning components <NUM>, <NUM>, and <NUM>, respectively. The positioning components <NUM>, <NUM>, and <NUM> may be hardware circuits that are part of or coupled to the processing systems <NUM>, <NUM>, and <NUM>, respectively, that, when executed, cause the UE <NUM>, the base station <NUM>, and the network entity <NUM> to perform the functionality described herein. In other aspects, the positioning components <NUM>, <NUM>, and <NUM> may be external to the processing systems <NUM>, <NUM>, and <NUM> (e.g., part of a modem processing system, integrated with another processing system, etc.). Alternatively, the positioning components <NUM>, <NUM>, and <NUM> may be memory modules (as shown in <FIG>) stored in the memory components <NUM>, <NUM>, and <NUM>, respectively, that, when executed by the processing systems <NUM>, <NUM>, and <NUM> (or a modem processing system, another processing system, etc.), cause the UE <NUM>, the base station <NUM>, and the network entity <NUM> to perform the functionality described herein.

The UE <NUM> may include one or more sensors <NUM> coupled to the processing system <NUM> to provide movement and/or orientation information that is independent of motion data derived from signals received by the WWAN transceiver <NUM>, the WLAN transceiver <NUM>, and/or the SPS receiver <NUM>. By way of example, the sensor(s) <NUM> may include an accelerometer (e.g., a micro-electrical mechanical systems (MEMS) device), a gyroscope, a geomagnetic sensor (e.g., a compass), an altimeter (e.g., a barometric pressure altimeter), and/or any other type of movement detection sensor. Moreover, the sensor(s) <NUM> may include a plurality of different types of devices and combine their outputs in order to provide motion information. For example, the sensor(s) <NUM> may use a combination of a multi-axis accelerometer and orientation sensors to provide the ability to compute positions in 2D and/or 3D coordinate systems.

In addition, the UE <NUM> includes a user interface <NUM> for providing indications (e.g., audible and/or visual indications) to a user and/or for receiving user input (e.g., upon user actuation of a sensing device such a keypad, a touch screen, a microphone, and so on). Although not shown, the base station <NUM> and the network entity <NUM> may also include user interfaces.

Referring to the processing system <NUM> in more detail, in the downlink, IP packets from the network entity <NUM> may be provided to the processing system <NUM>. The processing system <NUM> may implement functionality for an RRC layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The processing system <NUM> may provide RRC layer functionality associated with broadcasting of system information (e.g., master information block (MIB), system information blocks (SIBs)), 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 (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs), error correction through automatic repeat request (ARQ), concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, scheduling information reporting, error correction, priority handling, and logical channel prioritization.

The transmitter <NUM> and the receiver <NUM> may implement Layer-<NUM> functionality associated with various signal processing functions. Layer-<NUM>, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The transmitter <NUM> handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). Each stream may then be mapped to an orthogonal frequency division multiplexing (OFDM) subcarrier, multiplexed with a reference signal (e.g., pilot) in the time 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 symbol stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator may be used to determine the coding and modulation scheme, as well as for spatial processing. Each spatial stream may then be provided to one or more different antennas <NUM>. The transmitter <NUM> may modulate an RF carrier with a respective spatial stream for transmission.

At the UE <NUM>, the receiver <NUM> receives a signal through its respective antenna(s) <NUM>. The receiver <NUM> recovers information modulated onto an RF carrier and provides the information to the processing system <NUM>. The transmitter <NUM> and the receiver <NUM> implement Layer-<NUM> functionality associated with various signal processing functions. The receiver <NUM> may perform spatial processing on the information to recover any spatial streams destined for the UE <NUM>. If multiple spatial streams are destined for the UE <NUM>, they may be combined by the receiver <NUM> into a single OFDM symbol stream. The receiver <NUM> then converts the OFDM symbol stream from the time-domain to the frequency domain using a fast Fourier transform (FFT). These soft decisions may be based on channel estimates computed by a channel estimator. The soft decisions are then decoded and de-interleaved to recover the data and control signals that were originally transmitted by the base station <NUM> on the physical channel. The data and control signals are then provided to the processing system <NUM>, which implements Layer-<NUM> and Layer-<NUM> functionality.

In the uplink, the processing system <NUM> provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the core network. The processing system <NUM> is also responsible for error detection.

Similar to the functionality described in connection with the downlink transmission by the base station <NUM>, the processing system <NUM> provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression/decompression, and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through hybrid automatic repeat request (HARQ), priority handling, and logical channel prioritization.

Channel estimates derived by the channel estimator from a reference signal or feedback transmitted by the base station <NUM> may be used by the transmitter <NUM> to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the transmitter <NUM> may be provided to different antenna(s) <NUM>. The transmitter <NUM> may modulate an RF carrier with a respective spatial stream for transmission.

The uplink transmission is processed at the base station <NUM> in a manner similar to that described in connection with the receiver function at the UE <NUM>. The receiver <NUM> receives a signal through its respective antenna(s) <NUM>. The receiver <NUM> recovers information modulated onto an RF carrier and provides the information to the processing system <NUM>.

In the uplink, the processing system <NUM> provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE <NUM>. IP packets from the processing system <NUM> may be provided to the core network. The processing system <NUM> is also responsible for error detection.

For convenience, the UE <NUM>, the base station <NUM>, and/or the network entity <NUM> are shown in <FIG> as including various components that may be configured according to the various examples described herein. It will be appreciated, however, that the illustrated blocks may have different functionality in different designs.

The various components of the UE <NUM>, the base station <NUM>, and the network entity <NUM> may communicate with each other over data buses <NUM>, <NUM>, and <NUM>, respectively. The components of <FIG> may be implemented in various ways. In some implementations, the components of <FIG> may be implemented in one or more circuits such as, for example, one or more processors and/or one or more ASICs (which may include one or more processors). 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 <NUM> to <NUM> may be implemented by processor and memory component(s) of the UE <NUM> (e.g., by execution of appropriate code and/or by appropriate configuration of processor components). Similarly, some or all of the functionality represented by blocks <NUM> to <NUM> may be implemented by processor and memory component(s) of the base station <NUM> (e.g., by execution of appropriate code and/or by appropriate configuration of processor components). Also, some or all of the functionality represented by blocks <NUM> to <NUM> may be implemented by processor and memory component(s) of the network entity <NUM> (e.g., by execution of appropriate code and/or by appropriate configuration of processor components). For simplicity, various operations, acts, 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, acts, and/or functions may actually be performed by specific components or combinations of components of the UE, base station, positioning entity, etc., such as the processing systems <NUM>, <NUM>, <NUM>, the transceivers <NUM>, <NUM>, <NUM>, and <NUM>, the memory components <NUM>, <NUM>, and <NUM>, the positioning components <NUM>, <NUM>, and <NUM>, etc..

Various frame structures may be used to support downlink and uplink transmissions between network nodes (e.g., base stations and UEs). <FIG> is a diagram <NUM> illustrating an example of a downlink frame structure, according to aspects of the disclosure. <FIG> is a diagram <NUM> illustrating an example of channels within the downlink frame structure, according to aspects of the disclosure. <FIG> is a diagram <NUM> illustrating an example of an uplink frame structure, according to aspects of the disclosure. <FIG> is a diagram <NUM> illustrating an example of channels within an uplink frame structure, according to aspects of the disclosure. Other wireless communications technologies may have different frame structures and/or different channels.

LTE, and in some cases NR, utilizes OFDM on the downlink and single-carrier frequency division multiplexing (SC-FDM) on the uplink. Unlike LTE, however, NR has an option to use OFDM on the uplink as well. For example, the spacing of the subcarriers may be <NUM> and the minimum resource allocation (resource block) may be <NUM> subcarriers (or <NUM>). Consequently, the nominal FFT size may be equal to <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> for system bandwidth of <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> megahertz (MHz), respectively. For example, a subband may cover <NUM> (i.e., <NUM> resource blocks), and there may be <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> subbands for system bandwidth of <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>, respectively.

LTE supports a single numerology (subcarrier spacing, symbol length, etc.). In contrast, NR may support multiple numerologies (µ), for example, subcarrier spacing of <NUM>, <NUM>, <NUM>, <NUM>, and <NUM> or greater may be available. Table <NUM> provided below lists some various parameters for different NR numerologies.

In the example of <FIG>, a numerology of <NUM> is used. Thus, in the time domain, a frame (e.g., <NUM>) is divided into <NUM> equally sized subframes of <NUM> each, and each subframe includes one time slot. In <FIG>, time is represented horizontally (e.g., on the X axis) with time increasing from left to right, while frequency is represented vertically (e.g., on the Y axis) with frequency increasing (or decreasing) from bottom to top.

A resource grid may be used to represent time slots, each time slot including one or more time-concurrent resource blocks (RBs) (also referred to as physical RBs (PRBs)) in the frequency domain. The resource grid is further divided into multiple resource elements (REs). An RE may correspond to one symbol length in the time domain and one subcarrier in the frequency domain. In the numerology of <FIG>, for a normal cyclic prefix, an RB may contain <NUM> consecutive subcarriers in the frequency domain and seven consecutive symbols in the time domain, for a total of <NUM> REs. For an extended cyclic prefix, an RB may contain <NUM> consecutive subcarriers in the frequency domain and six consecutive symbols in the time domain, for a total of <NUM> REs.

Some of the REs carry downlink reference (pilot) signals (DL-RS). The DL-RS may include PRS in LTE, NRS in <NUM>, TRS, PTRS, CRS, CSI-RS, DMRS, PSS, SSS, SSB, etc. <FIG> illustrates exemplary locations of REs carrying PRS (labeled "R").

A collection of resource elements (REs) that are used for transmission of PRS is referred to as a "PRS resource. " The collection of resource elements can span multiple PRBs in the frequency domain and 'N' (e.g., <NUM> or more) consecutive symbol(s) within a slot in the time domain. In a given OFDM symbol in the time domain, a PRS resource occupies consecutive PRBs in the frequency domain.

The transmission of a PRS resource within a given PRB has a particular comb size (also referred to as the "comb density"). A comb size 'N' represents the subcarrier spacing (or frequency/tone spacing) within each symbol of a PRS resource configuration. Specifically, for a comb size `N,' PRS are transmitted in every Nth subcarrier of a symbol of a PRB. For example, for comb-<NUM>, for each of the fours symbols of the PRS resource configuration, REs corresponding to every fourth subcarrier (e.g., subcarriers <NUM>, <NUM>, <NUM>) are used to transmit PRS of the PRS resource. Currently, comb sizes of comb-<NUM>, comb-<NUM>, comb-<NUM>, and comb-<NUM> are supported for DL-PRS. <FIG> illustrates an exemplary PRS resource configuration for comb-<NUM> (which spans six symbols). That is, the locations of the shaded REs (labeled "R") indicate a comb-<NUM> PRS resource configuration.

A "PRS resource set" is a set of PRS resources used for the transmission of PRS signals, 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 is associated with a particular TRP (identified by a cell ID). In addition, the PRS resources in a PRS resource set have the same periodicity, a common muting pattern configuration, and the same repetition factor across slots. The periodicity may have a length selected from <NUM>m·{<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>} slots, with µ = <NUM>, <NUM>, <NUM>, <NUM>. The repetition factor may have a length selected from {<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>} slots.

A PRS resource ID in a PRS resource set is associated with a single beam (and/or beam ID) transmitted from a single TRP (where a TRP may transmit one or more beams). That is, each PRS resource of a PRS resource set may be transmitted on a different beam, and as such, a "PRS resource," or simply "resource," can also be referred to as a "beam. " Note that this does not have any implications on whether the TRPs and the beams on which PRS are transmitted are known to the UE.

A "PRS instance" or "PRS occasion" is one instance of a periodically repeated time window (e.g., a group of one or more consecutive slots) where PRS are expected to be transmitted. A PRS occasion may also be referred to as a "PRS positioning occasion," a "PRS positioning instance, a "positioning occasion," "a positioning instance," a "positioning repetition," or simply an "occasion," an "instance," or a "repetition.

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

Referring to <FIG>, a primary synchronization signal (PSS) is used by a UE to determine subframe/symbol timing and a physical layer identity. A secondary synchronization signal (SSS) is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a PCI. Based on the PCI, the UE can determine the locations of the aforementioned DL-RS. The physical broadcast channel (PBCH), which carries an MIB, may be logically grouped with the PSS and SSS to form an SSB (also referred to as an SS/PBCH). The MIB provides a number of RBs in the downlink system bandwidth and a system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH, such as system information blocks (SIBs), and paging messages.

The physical downlink control channel (PDCCH) carries downlink control information (DCI) within one or more control channel elements (CCEs), each CCE including one or more RE group (REG) bundles (which may span multiple symbols in the time domain), each REG bundle including one or more REGs, each REG corresponding to <NUM> resource elements (one resource block) in the frequency domain and one OFDM symbol in the time domain. The set of physical resources used to carry the PDCCH/DCI is referred to in NR as the control resource set (CORESET). In NR, a PDCCH is confined to a single CORESET and is transmitted with its own DMRS. This enables UE-specific beamforming for the PDCCH.

In the example of <FIG>, there is one CORESET per BWP, and the CORESET spans three symbols in the time domain. Unlike LTE control channels, which occupy the entire system bandwidth, in NR, PDCCH channels are localized to a specific region in the frequency domain (i.e., a CORESET). Thus, the frequency component of the PDCCH shown in <FIG> is illustrated as less than a single BWP in the frequency domain. Note that although the illustrated CORESET is contiguous in the frequency domain, it need not be. In addition, the CORESET may span less than three symbols in the time domain.

The DCI within the PDCCH carries information about uplink resource allocation (persistent and non-persistent) and descriptions about downlink data transmitted to the UE. Multiple (e.g., up to eight) DCIs can be configured in the PDCCH, and these DCIs can have one of multiple formats. For example, there are different DCI formats for uplink scheduling, for non-MIMO downlink scheduling, for MIMO downlink scheduling, and for uplink power control. A PDCCH may be transported by <NUM>, <NUM>, <NUM>, <NUM>, or <NUM> CCEs in order to accommodate different DCI payload sizes or coding rates.

As illustrated in <FIG>, some of the REs carry DMRS for channel estimation at the base station. The UE may additionally transmit SRS in, for example, the last symbol of a slot. The comb structure (also referred to as the "comb size") indicates the number of subcarriers in each symbol period carrying a reference signal (here, SRS). For example, a comb size of comb-<NUM> means that every fourth subcarrier of a given symbol carries the reference signal, whereas a comb size of comb-<NUM> means that every second subcarrier of a given symbol carries the reference signal. In the example of <FIG>, the illustrated SRS are both comb-<NUM>. The SRS may be used by a base station to obtain the channel state information (CSI) for each UE. CSI describes how an RF signal propagates from the UE to the base station and represents the combined effect of scattering, fading, and power decay with distance. The system uses the SRS for resource scheduling, link adaptation, massive MIMO, beam management, etc..

<FIG> illustrates an example of various channels within an uplink slot of a frame, according to aspects of the disclosure. A random-access channel (RACH), also referred to as a physical random-access channel (PRACH), may be within one or more slots within a frame based on the PRACH configuration. The PRACH may include six consecutive RB pairs within a slot. The PRACH allows the UE to perform initial system access and achieve uplink synchronization. A physical uplink control channel (PUCCH) may be located on edges of the uplink system bandwidth. The PUCCH carries uplink control information (UCI), such as scheduling requests, CSI reports, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and HARQ ACK/NACK feedback. The physical uplink shared channel (PUSCH) carries data, and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and/or UCI.

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

Generally, a UE transmits SRS to enable the receiving base station (either the serving base station or a neighboring base station) to measure the channel quality between the UE and the base station. However, SRS can also be used as uplink positioning reference signals for uplink positioning procedures, such as uplink time-difference of arrival (UL-TDOA), multi-round-trip-time (multi-RTT), downlink angle-of-arrival (DL-AoA), etc..

Several enhancements over the previous definition of SRS have been proposed for SRS-for-positioning (also referred to as "UL-PRS"), such as a new staggered pattern within an SRS resource (except for single-symbol/comb-<NUM>), a new comb type for SRS, new sequences for SRS, a higher number of SRS resource sets per component carrier, and a higher number of SRS resources per component carrier. In addition, the parameters SpatialRelationInfo and PathLossReference are to be configured based on a downlink reference signal or SSB from a neighboring TRP. Further still, one SRS resource may be transmitted outside the active BWP, and one SRS resource may span across multiple component carriers. Also, SRS may be configured in RRC connected state and only transmitted within an active BWP. Further, there may be no frequency hopping, no repetition factor, a single antenna port, and new lengths for SRS (e.g., <NUM> and <NUM> symbols). There may also be open-loop power control and not closed-loop power control, and comb-<NUM> (i.e., an SRS transmitted every eighth subcarrier in the same symbol) may be used. Lastly, the UE may transmit through the same transmit beam from multiple SRS resources for UL-AoA. All of these are features that are additional to the current SRS framework, which is configured through RRC higher layer signaling (and potentially triggered or activated through MAC control element (CE) or DCI).

Note that the terms "positioning reference signal" and "PRS" may sometimes refer to specific reference signals that are used for positioning in LTE systems. However, as used herein, unless otherwise indicated, the terms "positioning reference signal" and "PRS" refer to any type of reference signal that can be used for positioning, such as but not limited to, PRS in LTE, NRS in <NUM>, TRS, PTRS, CRS, CSI-RS, DMRS, PSS, SSS, SSB, SRS, UL-PRS, etc. In addition, the terms "positioning reference signal" and "PRS" refer to downlink or uplink positioning reference signals, unless otherwise indicated. A downlink positioning reference signal may be referred to as a "DL-PRS," and an uplink positioning reference signal (e.g., an SRS-for-positioning, PTRS) may be referred to as an "UL-PRS. " In addition, for signals that may be transmitted in both the uplink and downlink (e.g., DMRS, PTRS), the signals may be prepended with "UL" or "DL" to distinguish the direction. For example, "UL-DMRS" may be differentiated from "DL-DMRS.

In <NUM> NR, there may not be precise timing synchronization across the network. Instead, it may be sufficient to have coarse time-synchronization across gNBs (e.g., within a cyclic prefix (CP) duration of the OFDM symbols). RTT-based methods generally only need coarse timing synchronization, and as such, are a preferred positioning method in NR.

In a network-centric RTT estimation, the serving base station instructs the UE to scan for / receive the RTT measurement signals from two or more neighboring base stations (and typically the serving base station, as at least three base stations are needed). The one or more base stations transmit RTT measurement signals on low reuse resources (i.e., resources used by the base station to transmit system information) allocated by the network (e.g., location server <NUM>, LMF <NUM>, SLP <NUM>). The UE records the arrival time (also referred to as the receive time, reception time, time of reception, or time of arrival) of each RTT measurement signal relative to the UE's current downlink timing (e.g., as derived by the UE from a downlink signal received from its serving base station), and transmits a common or individual RTT response message to the involved base stations (e.g., when instructed by its serving base station), and may include each of the measured arrival times in a payload of the RTT response message(s).

A UE-centric RTT estimation is similar to the network-based method, except that the UE transmits uplink RTT measurement signal(s) (e.g., when instructed by a serving base station or location server), which are received by multiple base stations in the neighborhood of the UE. Each involved base station responds with a downlink RTT response message, which may include the arrival time of the RTT measurement signal at the base station in the RTT response message payload.

For both network-centric and UE-centric procedures, the side (network or UE) that performs the RTT calculation typically (though not always) transmits the first message(s) or signal(s) (e.g., RTT measurement signal(s)), while the other side responds with one or more RTT response messages or signals that may include the arrival (or receive) time(s) of the first message(s) or signal(s) in the RTT response message payload.

<FIG> illustrates an exemplary wireless communications system <NUM> according to aspects of the disclosure. In the example of <FIG>, a UE <NUM> (which may correspond to any of the UEs described herein) is attempting to calculate an estimate of its location, or assist another positioning entity (e.g., a base station or core network component, another UE, a location server, a third party application, etc.) to calculate an estimate of its location. The UE <NUM> may communicate wirelessly with a plurality of base stations (BS) <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> (collectively, base stations <NUM>, and which may correspond to any of the base stations described herein) using RF signals and standardized protocols for the modulation of the RF signals and the exchange of information packets. By extracting different types of information from the exchanged signals, and utilizing the layout of the wireless communications system <NUM> (i.e., the base stations' locations, geometry, etc.), the UE <NUM> may determine its location, or assist in the determination of its location, in a predefined reference coordinate system. In an aspect, the UE <NUM> may specify its location using a two-dimensional coordinate system; however, the aspects disclosed herein are not so limited, and may also be applicable to determining locations using a three-dimensional coordinate system, if the extra dimension is desired. Additionally, while <FIG> illustrates one UE <NUM> and three base stations <NUM>, as will be appreciated, there may be more UEs <NUM> and more base stations <NUM>.

To support location estimates, the base stations <NUM> may be configured to broadcast reference RF signals (e.g., PRS, NRS, CRS, TRS, CSI-RS, SSB, PSS, SSS, etc.) to UEs <NUM> in their coverage area to enable a UE <NUM> to measure characteristics of such reference signals. For example, the UE <NUM> may measure the time of arrival (ToA) of specific reference signals (e.g., PRS, NRS, CRS, CSI-RS, etc.) transmitted by at least three different base stations <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> and may use the RTT positioning method to report these ToAs (and additional information) back to the serving base station <NUM> or another positioning entity (e.g., location server <NUM>, LMF <NUM>, SLP <NUM>).

In an aspect, although described as the UE <NUM> measuring reference signals from a base station <NUM>, the UE <NUM> may measure reference signals from one of multiple cells or TRPs supported by a base station <NUM>. Where the UE <NUM> measures reference signals transmitted by a cell/TRP supported by a base station <NUM>, the at least two other reference signals measured by the UE <NUM> to perform the RTT procedure would be from cells/TRPs supported by base stations <NUM> different from the first base station <NUM> and may have good or poor signal strength at the UE <NUM>.

In order to determine the location (x, y) of the UE <NUM>, the entity determining the location of the UE <NUM> needs to know the locations of the base stations <NUM>, which may be represented in a reference coordinate system as (xk, yk), where k=<NUM>, <NUM>, <NUM> in the example of <FIG>. Where one of the base stations <NUM> (e.g., the serving base station) or the UE <NUM> determines the location of the UE <NUM>, the locations of the involved base stations <NUM> may be provided to the serving base station <NUM> or the UE <NUM> by a location server with knowledge of the network geometry (e.g., location server <NUM>, LMF <NUM>, SLP <NUM>). Alternatively, the location server may determine the location of the UE <NUM> using the known network geometry.

Either the UE <NUM> or the respective base station <NUM> may determine the distance <NUM> (dk, where k=<NUM>, <NUM>, <NUM>) between the UE <NUM> and the respective base station <NUM>. Specifically, in the example of <FIG>, the distance <NUM>-<NUM> between the UE <NUM> and the base station <NUM>-<NUM> is di, the distance <NUM>-<NUM> between the UE <NUM> and the base station <NUM>-<NUM> is d<NUM>, and the distance <NUM>-<NUM> between the UE <NUM> and the base station <NUM>-<NUM> is d<NUM>. In an aspect, determining the RTT of the RF signals exchanged between the UE <NUM> and any base station <NUM> can be performed and converted to a distance <NUM> (dk). As discussed further below with reference to <FIG>, RTT techniques can measure the time between sending an RTT measurement signal and receiving an RTT response signal. These methods may utilize calibration to remove any processing delays. In some environments, it may be assumed that the processing delays for the UE <NUM> and the base stations <NUM> are the same. However, such an assumption may not be true in practice.

Once each distance <NUM> is determined, the UE <NUM>, a base station <NUM>, or the location server (e.g., location server <NUM>, LMF <NUM>, SLP <NUM>) can solve for the location (x, y) of the UE <NUM> by using a variety of known geometric techniques, such as, for example, trilateration. From <FIG>, it can be seen that the location of the UE <NUM> ideally lies at the common intersection of three semicircles, each semicircle being defined by radius dk and center (xk, yk), where k=<NUM>, <NUM>, <NUM>.

A location estimate (e.g., for a UE <NUM>) may be referred to by other names, such as a position estimate, location, position, position fix, fix, or the like. A position estimate may be geodetic and comprise coordinates (e.g., latitude, longitude, and possibly altitude) or may be civic and comprise a street address, postal address, or some other verbal description of a location. A position estimate may further be defined relative to some other known location or defined in absolute terms (e.g., using latitude, longitude, and possibly altitude). A position estimate may include an expected error or uncertainty (e.g., by including an area or volume within which the location is expected to be included with some specified or default level of confidence).

<FIG> is an exemplary diagram <NUM> showing exemplary timings of RTT measurement signals exchanged between a base station <NUM> (e.g., any of the base stations described herein) and a UE <NUM> (e.g., any of the UEs described herein), according to aspects of the disclosure. In the example of FIG. 6A, the base station <NUM> sends an RTT measurement signal <NUM> (e.g., PRS, NRS, CRS, CSI-RS, etc.) to the UE <NUM> at time T<NUM>. The RTT measurement signal <NUM> has some propagation delay TProp as it travels from the base station <NUM> to the UE <NUM>. At time T<NUM> (the ToA of the RTT measurement signal <NUM> at the UE <NUM>), the UE <NUM> receives/measures the RTT measurement signal <NUM>. After some UE processing time, the UE <NUM> transmits an RTT response signal <NUM> (e.g., an SRS, UL-PRS, DMRS, etc.) at time T<NUM>. After the propagation delay TProp, the base station <NUM> receives/measures the RTT response signal <NUM> from the UE <NUM> at time T<NUM> (the ToA of the RTT response signal <NUM> at the base station <NUM>).

In order to identify the ToA (e.g., T<NUM>) of an RF signal (e.g., an RTT measurement signal <NUM>) transmitted by a given network node, the receiver (e.g., UE <NUM>) first jointly processes all the resource elements (REs) on the channel on which the transmitter (e.g., base station <NUM>) is transmitting the RF signal, and performs an inverse Fourier transform to convert the received RF signals to the time domain. The conversion of the received RF signals to the time domain is referred to as estimation of the channel energy response (CER). The CER shows the peaks on the channel over time, and the earliest "significant" peak should therefore correspond to the ToA of the RF signal. Generally, the receiver will use a noise-related quality threshold to filter out spurious local peaks, thereby presumably correctly identifying significant peaks on the channel. For example, the UE <NUM> may choose a ToA estimate that is the earliest local maximum of the CER that is at least X decibels (dB) higher than the median of the CER and a maximum Y dB lower than the main peak on the channel. The receiver determines the CER for each RF signal from each transmitter in order to determine the ToA of each RF signal from the different transmitters.

The RTT response signal <NUM> may explicitly include the difference between time T<NUM> and time T<NUM> (i.e., TRx→Tx <NUM>), referred to as the "UE Rx-Tx" measurement. Alternatively, it may be derived from the timing advance (TA), i.e., the relative UL/DL frame timing and specification location of uplink reference signals. (Note that the TA is usually the RTT between the base station <NUM> and the UE <NUM>, or double the propagation time in one direction. ) Using this measurement and the difference between time T<NUM> and time T<NUM> (i.e., TTx→Rx <NUM>), referred to as the "BS Tx-Rx" measurement, the base station <NUM> can calculate the distance to the UE <NUM> as: <MAT> where c is the speed of light.

As illustrated in <FIG>, the UE <NUM> can perform an RTT procedure with multiple base stations <NUM>, referred to as "multi-RTT" or "multi-cell RTT. " Such an RTT procedure does not require synchronization between the involved base stations <NUM>. As discussed above with reference to <FIG>, the UE <NUM> and the involved base stations <NUM> report their respective measurements to a positioning entity (e.g., the UE <NUM>, a serving base station <NUM>, a location server, such as location server <NUM>, LMF <NUM>, SLP <NUM>), which calculates an estimate of the location of the UE <NUM> based on the measurements.

The TA is a MAC control element (MAC-CE) or random-access response (RAR) that is used to control uplink signal transmission timing. A base station (e.g., base station <NUM>) periodically measures the time difference between reception of the PUSCH (see e.g., <FIG>), PUCCH (see e.g., <FIG>), and/or SRS (see e.g., <FIG>) from a UE (e.g., UE <NUM>) and the base station's own frame timing. If needed, the base station can send a TA command to the UE instructing it to change the PUSCH/PUCCH/SRS transmission time to better align with the base station's frame timing. For example, if the PUSCH/PUCCH/SRS arrives at the base station too early, the base station can send a TA command to the UE instructing it to send the PUSCH/PUCCH/SRS some period of time later than it is currently sending it. Alternatively, if the PUSCH/PUCCH/SRS arrives at the base station too late, the base station can send a TA command to the UE instructing it to send the PUSCH/PUCCH/SRS some period of time earlier than it is currently sending it.

To translate each value of a TA command to a physical time delay or timing advance value, the UE performs the following calculation if the TA command is received in a MAC-CE: <MAT> where NTA is the new TA value, NTA_old is the previous TA value, TA is an index value (from <NUM> to <NUM>) from the MAC-CE, and µ indicates the subcarrier numerology (see Table <NUM>).

If the TA command is received in an RAR, the UE performs the following calculation: <MAT> where NTA is the new TA value, TA is an index value (from <NUM> to <NUM>) from the RAR, and µ indicates the subcarrier numerology (e.g., from <NUM> to <NUM>).

Once the UE calculates the new TA value, it performs the following calculation to determine the actual uplink transmission time offset to be applied to the beginning of a subsequent uplink slot: <MAT> where NTA is the new TA value as calculated in Equation <NUM> or Equation <NUM>, NTAoffset depends on the frequency range and band of the cell used for uplink transmission (as shown in Table <NUM> below), and Tc = <NUM> nanoseconds (ns).

For a TA command received on an uplink slot n, the corresponding adjustment of the uplink transmission timing (as calculated from Equation <NUM>) applies from the beginning of uplink slot n+k, where <MAT>, NT,<NUM> is a time duration of N<NUM> symbols corresponding to a PDSCH reception time for PDSCH processing capability <NUM> when an additional PDSCH DMRS is configured, NT,<NUM> is a time duration of N<NUM> symbols corresponding to a PUSCH preparation time for PUSCH processing capability <NUM>, NTAmax is the maximum TA value that can be provided by the TA command field, <MAT> is a number of slots per subframe, and Tsf is the subframe duration of <NUM>.

A TA command may have the following granularity (i.e., the step size of the delay or advance): <NUM> ns for <NUM> subcarrier spacing, <NUM> ns for <NUM> subcarrier spacing, <NUM> ns for <NUM> subcarrier spacing, and <NUM> ns for <NUM> subcarrier spacing. That is, for <NUM> subcarrier spacing, the delay specified by a TA command would be a delay of some multiple (e.g., <NUM>, <NUM>, <NUM>, etc.) of <NUM> ns.

In some cases, a UE may be configured to receive multiple reference signals (e.g., PRS) from one base station inside a particular radio frame. The UE may further be configured to transmit multiple SRS (which may be part of the same or different component carriers or bands) inside the same frame (e.g., as part of an RTT procedure). For example, during an RTT positioning session, a base station may transmit multiple PRS as the RTT measurement signal (e.g., RTT measurement signal <NUM>) and the UE may respond with multiple SRS as the RTT response signal (e.g., RTT response signal <NUM>). In that case, the UE averages the CER of all of the PRS to determine the time of arrival (e.g., T<NUM> in <FIG>) of the RTT measurement signal. Similarly, the base station averages the CER of all of the SRS to determine the time of arrival (e.g., T<NUM> in <FIG>) of the RTT response signal. This averaging of multiple reference signals improves the accuracy of the time of arrival estimates, and thereby, the location estimate. However, if the UE receives a MAC-CE command that changes the TA between the SRS transmissions in a radio frame, it can result in degraded positioning performance.

<FIG> is a diagram <NUM> of an exemplary scenario in which a positioning session is interrupted by a TA command. In <FIG>, a base station (labeled "gNB1") transmits multiple PRS (labeled "PRS1") during a radio frame <NUM>, and a UE receives those PRS from the base station during a corresponding radio frame <NUM>. For example, the base station transmits "PRS1" in a first slot <NUM> (labeled "Slot X") and a second slot <NUM> (labeled "Slot X+N") of radio frame <NUM>, and the UE receives the "PRS1" in a first slot <NUM> and a second slot <NUM>, respectively, of a radio frame <NUM>. Because the UE receives "PRS1" as part of a positioning session, the UE transmits an SRS (labeled "SRS1") in a subsequent slot. Thus, in the example of <FIG>, the UE transmits "SRS1" <NUM> after receiving "PRS1" in slot <NUM> and "SRS1" <NUM> after receiving "PRS1" in slot <NUM>.

As shown in <FIG>, the UE receives a TA command in a MAC-CE <NUM> after receiving the "PRS1" in slot <NUM> and before sending the "SRS1" <NUM>. As will be appreciated, the times of arrival of the "SRS1" <NUM> and <NUM> relative to the base station's frame time will be different from each other by at least the amount of the new TA derived from the MAC-CE <NUM>. However, as is apparent, the difference in the times of arrival is not based on a difference in location between the UE and the base station, propagation characteristics of the SRS, or any other relevant factor, but rather, simply the new TA. For example, if the TA command is to add an additional delay to the transmission of uplink signals (e.g., "SRS1"), then for the SRS transmitted after the TA command is applied (e.g., "SRS1" <NUM>), it will appear as if the distance between the UE and the base station is greater than it actually is. As such, simply averaging the times of arrival, or CERs, of the "SRS1" <NUM> and <NUM> would result in an inaccurate location estimate. Depending on the granularity/step size of the delay or advance (e.g., <NUM> ns for <NUM> subcarrier spacing), the decrease in positioning accuracy can be quite significant. For example, the propagation time between the UE and the base station could appear to be <NUM> ns longer or shorter than it actually is.

There are various options for what the UE can report as the UE Rx-Tx measurement (e.g., TRx→Tx <NUM>) if a TA command is received during a positioning session. In LTE, the specified/requested positioning accuracy for the positioning session is not guaranteed to be met if a TA command is received during a positioning session. As a first option, the UE may timestamp each UE Rx-Tx measurement at the slot level with respect to the reference cell (or serving cell). As a second option, the timestamp of each UE Rx-Tx measurement may be such that the UE reports the following tuple of information: {slot ID in which PRS is received, slot ID in which SRS is transmitted}. As a third option, the reported UE Rx-Tx measurement may refer to the latest or earliest measurement inside the reported frame. As a fourth option, the UE may not apply the TA command to SRS used only for positioning, but may instead apply it for the remaining uplink channels. In this case, there would likely need to be gaps between the SRS-for-positioning and the uplink channels in the adjacent OFDM symbols. However, it is possible that the gaps may not be needed if the TA is small enough (e.g., within the size of the CP) to perform via a phase-ramp in the frequency domain (circular shift). Alternatively, the gaps may not be needed if the TA can be covered by the existing downlink-to-uplink switch gap (at the end of the slot for SRS). This may hold only for certain values of the TA command, and the gap configuration could be a function of the TA command. If the SRS is used for both positioning and communications, then the UE may be expected to apply the TA command as specified by the serving cell.

All of these options enable the base station or other positioning entity (e.g., location server <NUM>, LMF <NUM>, SLP <NUM>) to exclude CERs of the SRS received after the TA command is applied from being averaged with the CERs of SRS received before the TA command is applied. While this may improve positioning performance over calculating an average of all SRS, there may not be very many SRS transmitted in a positioning session, and therefore, the base station not being able to average the CERs of all SRS can still result in poor positioning performance.

The foregoing options have additional drawbacks. For example, these options would result in high operational constraints that may not be acceptable for <NUM> NR, especially in mobility (i.e., handover) cases. In addition, the requested positioning accuracy for UL-TDOA or multi-RTT positioning methods may only be guaranteed if a TA command is not received during a positioning session. Regarding the second and third options above specifically, if the UE adds a timestamp with a larger granularity of the time period during which the SRS transmission is valid, it would mean that the receiving base station (especially neighboring base stations) (<NUM>) would not be able to average the received SRS across different slots, since it would not know how much the CER of the new SRS is shifted in time, and (<NUM>) would only be able to perform one-shot measurements and then forward them to the positioning entity.

The present disclosure proposes signaling aspects to ensure that both serving and neighboring base stations are able to compensate for different uplink timings of SRS, average the CERs of the SRS, and then derive the subsequent positioning measurements, such as the received time of arrival (RTOA) (e.g., T<NUM> in <FIG>) or the BS Tx-Rx measurement (e.g., TTx→Rx <NUM> in <FIG>). For example, the present disclosure provides techniques for the UE to report the applied SRS adjustment(s) within a measurement window.

During a configured measurement window, if the UE transmits SRS with different uplink timing (due to the reception of a TA command), then the UE can include a report in an uplink channel (e.g., PUSCH or PUCCH) indicating the timing adjustment of the corresponding SRS in the measurement window. As a first option, this information may be received by the serving base station and then distributed to the neighboring base stations through the Xn interface. In that way, all of the involved base stations can adjust their SRS reception times and average the adjusted SRS CERs to obtain the RTOA or the BS Tx-Rx measurements. As a second option, this information may be received by the positioning entity (e.g., the serving base station, a location server), and the positioning entity can distribute it to the involved base stations, which can use the information to adjust the SRS reception timing. Then, the base stations can forward the RTOAs of the SRS to the positioning entity.

In an aspect, the measurement window can correspond to a positioning session, a radio frame, a collection of frames, a subframe, a collection of subframes, a slot, a collection of slots, a collection of consecutive SRS transmissions from the UE (e.g., <NUM> SRS transmissions), or the like. The UE can be configured with this measurement window through higher layer signaling (e.g., LTE positioning protocol (LPP), RRC). If no timing adjustment to the SRS transmissions is performed inside the measurement window, the UE can report "<NUM>" as the needed adjustment, or may not report any number.

In an aspect, the timing adjustment of SRS transmissions need only be reported if the requested positioning accuracy is larger than a specified (threshold) value. The threshold value could be dependent on the system numerology (see Table <NUM>). Alternatively, or additionally, the threshold value could be dependent on the granularity of the reporting of the UE Rx-Tx measurement. For example, if the UE Rx-Tx measurement is reported with a granularity of `X' ns, then, if the SRS is adjusted with a TA that results in a change of much less than 'X' ns, there would be no need to report the SRS timing adjustment. However, if SRS transmission is adjusted by only a small amount (e.g., some 'Y' much less than 'X'), but after several such adjustments, the total adjustment is comparable to 'X,' then a cumulative value could be reported, possibly with a report of the window of time over which that cumulative adjustment was distributed.

In an aspect, the reporting of the timing adjustment could be discretized to match the corresponding TA command. For example, there may be a TA step size of <MAT> in NR. Thus, the reported timing adjustment to SRS transmissions would match the value of the corresponding TA command. In this case, the report may include 'Z' bits to cover the cases <MAT>. In an aspect, each 'Z' bits can indicate that the current SRS transmission has been adjusted with respect to the previous SRS transmission. Alternatively, each 'Z' bits can indicate that the SRS transmission has been adjusted with respect to the first SRS transmission in the measurement window.

In an aspect, the timing adjustment may be reported with a single bit. In an aspect, the report for a measurement window may include one bit per SRS transmission (or slot / subframe / frame ID) inside the measurement window. As a first option, this bit can indicate that the `Xth' SRS has been adjusted with respect to the previous SRS. For example, given <NUM> SRS transmissions in the measurement window and a TA command applied after the sixth SRS transmission, the report may include six '<NUM>' bits for the first six SRS transmissions, followed by one '<NUM>' bit for the first SRS transmission transmitted after the new TA is applied, followed by three '<NUM>' bits indicating no further TA change from the previous (seventh) SRS transmission. As a second option, this bit can indicate that the `Xth' SRS has been adjusted with respect to the first SRS in the measurement window. For example, given <NUM> SRS transmissions in the measurement window and a TA command applied after the sixth SRS transmission, the report may include six '<NUM>' bits for the first six SRS transmissions, followed by four '<NUM>' bits for the remaining SRS transmissions.

In an alternative aspect, the report may include one bit for all of the SRS transmissions in the measurement window, indicating whether or not at least one SRS in the measurement window was adjusted. For example, given <NUM> SRS transmissions in the measurement window and a TA command applied after the sixth SRS transmission, the report may be a single bit set to '<NUM>. ' In this way, a report indicating that a second timing adjustment parameter has been applied to a second SRS indicates that the second timing adjustment associated with the second SRS is different than a first timing adjustment associated with a first SRS.

In an aspect, the UE could report a set of SRS indexes indicating when the reported SRS transmission timing changed. The likelihood that the UE receives more than some number 'X' (e.g., <NUM>, <NUM>, <NUM>, etc.) TA commands during a measurement window is small. As such, the UE would only need to report up to 'X' SRS index values (or slot / subframe / frame indexes) corresponding to the first SRS transmitted after the timing adjustment is applied. For example, given <NUM> SRS transmissions in the measurement window and a TA command applied after the third and sixth SRS transmissions, the report may include the index values for the fourth and seventh SRS transmissions (i.e., the first SRS transmissions after the TA commands were received).

In an aspect, when the UE does not report the exact value of the SRS timing adjustment applied (and it only reports whether or not the SRS transmission timing has been adjusted), then the base station may assume that up to a specific timing adjustment was applied. For example, the maximum timing adjustment may be one TA step (e.g., <NUM> ns for <NUM> subcarrier spacing) or 'Z' (e.g., <NUM>, <NUM>, etc.) TA steps. 'Z' may also be reported by the UE separately or in the same report.

In an aspect, the serving base station may forward the TA commands to the neighboring base stations. However, the UE may not apply the TA command for some number of subsequent SRS transmissions since it may miss the TA command or because it has simply not applied it yet. To address this issue, the neighboring base stations can perform some implementation-based solutions, such as a blind check of whether or not the TA command was applied, to attempt to average the SRS measurements correctly. The UE may still report information on whether/which SRS transmissions are affected, as described above. Together with the TA information received from the serving base station, the neighboring base station(s) may combine these two different information sources to obtain the exact timing of the SRS transmissions.

In an aspect, the SRS transmission timing can be adjusted due to the reception of an explicit TA command, as described in the foregoing, or due to autonomous UE correction based on the UE sensing a change in the downlink timing. The reporting solutions described above apply in both cases. The same solution can be used because, although the TA command is known to the base station that issues it, there is no precise action-time specified for when the UE will apply it. In addition, the UE may spread out the application of the TA over several slots, so it may be hard for the base station to detect.

<FIG> illustrates an exemplary method <NUM> of wireless communication, according to aspects of the disclosure. In an aspect, the method <NUM> may be performed by any of the UEs described herein.

At <NUM>, the UE transmits, at a first time during a measurement window for positioning purposes, a first uplink reference signal in accordance with a first timing adjustment parameter, wherein the first time is offset from a downlink frame time (e.g., the start of reception of a downlink radio frame) of a base station (e.g., any of the base stations described herein) by an amount of the first timing adjustment parameter. In an aspect, operation <NUM> may be performed by WWAN transceiver <NUM>, processing system <NUM>, memory component <NUM>, and/or positioning component <NUM>, any or all of which may be considered means for performing this operation.

At <NUM>, the UE determines whether to use a second timing adjustment parameter. In an aspect, operation <NUM> may be performed by WWAN transceiver <NUM>, processing system <NUM>, memory component <NUM>, and/or positioning component <NUM>, any or all of which may be considered means for performing this operation.

At <NUM>, the UE transmits, in response to the determination to use the second timing adjustment parameter, at a second time during the measurement window, a second uplink reference signal in accordance with a second timing adjustment parameter, wherein the second time is offset from the downlink frame time of the base station by an amount of the second timing adjustment parameter. In an aspect, operation <NUM> may be performed by WWAN transceiver <NUM>, processing system <NUM>, memory component <NUM>, and/or positioning component <NUM>, any or all of which may be considered means for performing this operation.

At <NUM>, the UE transmits a report indicating that the second timing adjustment parameter has been applied to at least the second uplink reference signal. In an aspect, there may not have been any timing adjustment changes, and the report may indicate that there have been no changes. In an aspect, operation <NUM> may be performed by WWAN transceiver <NUM>, processing system <NUM>, memory component <NUM>, and/or positioning component <NUM>, any or all of which may be considered means for performing this operation.

<FIG> illustrates an exemplary method <NUM> of wireless communication, according to aspects of the disclosure. In an aspect, the method <NUM> may be performed by any of the base stations described herein.

At <NUM>, the base station receives, from a UE (e.g., any of the UEs described herein) during a measurement window for positioning purposes, a first uplink reference signal. In an aspect, operation <NUM> may be performed by WWAN transceiver <NUM>, processing system <NUM>, memory component <NUM>, and/or positioning component <NUM>, any or all of which may be considered means for performing this operation.

At <NUM>, the base station receives, from the UE during the measurement window, a second uplink reference signal. In an aspect, operation <NUM> may be performed by WWAN transceiver <NUM>, processing system <NUM>, memory component <NUM>, and/or positioning component <NUM>, any or all of which may be considered means for performing this operation.

At <NUM>, the base station receives a report indicating that a timing adjustment parameter has been adjusted for at least the second uplink reference signal. In an aspect, operation <NUM> may be performed by WWAN transceiver <NUM>, processing system <NUM>, memory component <NUM>, and/or positioning component <NUM>, any or all of which may be considered means for performing this operation.

At <NUM>, the base station determines one or more positioning measurements based on the first uplink reference signal, the second uplink reference signal, and information in the report related to the second uplink reference signal. In an aspect, operation <NUM> may be performed by WWAN transceiver <NUM>, processing system <NUM>, memory component <NUM>, and/or positioning component <NUM>, any or all of which may be considered means for performing this operation.

The various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose processor, a DSP, an ASIC, an FPGA, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein.

The methods, sequences and/or algorithms described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in random access memory (RAM), flash memory, read-only memory (ROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. The ASIC may reside in a user terminal (e.g., UE).

In one or more exemplary aspects, the functions described may be implemented in hardware, software, firmware, or any combination thereof. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers.

Claim 1:
A user equipment, UE, (<NUM>, <NUM>) comprising:
a memory;
at least one transceiver; and
at least one processor communicatively coupled to the memory and the at least one transceiver, the at least one processor configured to:
cause the at least one transceiver to transmit, at a first time during a measurement window for positioning purposes, a first uplink reference signal in accordance with a first timing adjustment parameter, wherein the first time is offset from a downlink frame time of a base station (<NUM>, <NUM>) by an amount of the first timing adjustment parameter; and characterised in that the processor is further configured to cause the at least one transceiver to transmit a report indicating that the first timing adjustment parameter has been applied to at least the first uplink reference signal.