Reconfigurable Intelligent Surface (RIS) Beam Sweeping of Sounding Reference Signal (SRS) for Angle of Departure (AOD) Based Positioning

Abstract

Techniques for wireless communications are disclosed. In one aspect, a user equipment (UE) may obtain configuration information identifying resources for sounding reference signal (SRS) positioning. The UE may transmit multiple SRS transmissions to a reconfigurable intelligent surface (RIS) at different times according to the configuration information. The UE may receive multiple SRS transmissions from the RIS comprising reflections of the multiple SRS transmissions to the RIS, each of the multiple SRS transmissions from the RIS being transmitted at a different angle of departure (AoD) from the RIS. The UE may measure each of the multiple SRS transmissions from the RIS to generate multiple measurements. The UE may perform a positioning operation based on the multiple measurements.

Description

[Background technology]

[0001] 1. Field of disclosure Aspects of the present disclosure relate generally to wireless communications.

[0002] 2. Description of Related Technology

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

[0003]

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

[0004]

[0004] The following provides a simplified summary relating to one or more aspects disclosed herein. Therefore, the following summary should not be considered as an extensive overview of all contemplated aspects, nor should it be considered as identifying key or critical elements of all contemplated aspects or defining the scope relating to any particular aspect. Therefore, the sole purpose of the following summary is to present some concepts of one or more aspects of the mechanisms disclosed herein in a simplified form prior to the detailed description presented below.

[0005]

[0005] In one aspect, a method of wireless communications performed by a user equipment (UE) includes obtaining configuration information identifying resources for sounding reference signal (SRS) positioning, transmitting multiple SRS transmissions to a reconfigurable intelligent surface (RIS) at different times in accordance with the configuration information, receiving multiple SRS transmissions from the RIS including reflections of the multiple SRS transmissions to the RIS, each of the multiple SRS transmissions from the RIS being transmitted at a different angle of departure (AoD) from the RIS, measuring each of the multiple SRS transmissions from the RIS to generate multiple measurements, and performing a positioning operation based on the multiple measurements.

[0006]

[0006] In one aspect, a method of wireless communications performed by a reconfigurable intelligent surface (RIS) includes obtaining configuration information identifying resources for sounding reference signal (SRS) positioning, receiving multiple SRS transmissions at different times from a user equipment (UE), and transmitting multiple SRS transmissions including reflections of the multiple SRS transmissions received from the UE, where each of the multiple SRS transmissions from the RIS is transmitted at a different angle of departure (AoD) from the RIS in accordance with the configuration information.

[0007]

[0007] In one aspect, a method of wireless communications performed by a location server includes transmitting first configuration information to a reconfigurable intelligent surface (RIS) identifying resources for sounding reference signal (SRS) positioning and transmitting second configuration information to a user equipment (UE) identifying resources for sounding reference signal (SRS) positioning, wherein each of the first configuration information and the second configuration information indicates a number of SRS resources, a time at which the UE transmits an SRS transmission to the RIS, an expected time at which the UE will receive a reflection of the SRS transmission from the RIS, an uncertainty in the expected time at which the UE will receive a reflection of the SRS transmission from the RIS, an angle of departure (AoD) at which the RIS transmits the reflection of the SRS transmission from the UE, or a combination thereof.

[0008]

[0008] In one aspect, a user equipment (UE) includes a memory, at least one transceiver, and at least one processor communicatively coupled to the memory and the at least one transceiver, wherein the at least one processor is configured to obtain configuration information identifying resources for sounding reference signal (SRS) positioning, transmit multiple SRS transmissions via the at least one transceiver to a reconfigurable intelligent surface (RIS) at different times in accordance with the configuration information, receive multiple SRS transmissions from the RIS via the at least one transceiver, the multiple SRS transmissions including reflections of the multiple SRS transmissions to the RIS, each of the multiple SRS transmissions from the RIS being transmitted at a different angle of departure (AoD) from the RIS, measure each of the multiple SRS transmissions from the RIS to generate multiple measurements, and perform a positioning operation based on the multiple measurements.

[0009]

[0009] In one aspect, a reconfigurable intelligent surface (RIS) includes a memory, at least one transceiver, and at least one processor communicatively coupled to the memory and the at least one transceiver, wherein the at least one processor is configured to obtain configuration information identifying resources for sounding reference signal (SRS) positioning, receive multiple SRS transmissions at different times from a user equipment (UE) via the at least one transceiver, and transmit multiple SRS transmissions via the at least one transceiver including reflections of the multiple SRS transmissions received from the UE, wherein each of the multiple SRS transmissions from the RIS is transmitted at a different angle of departure (AoD) from the RIS in accordance with the configuration information.

[0010]

[0010] In one aspect, a location server includes a memory, at least one transceiver, and at least one processor communicatively coupled to the memory and the at least one transceiver, wherein the at least one processor is configured to transmit first configuration information identifying resources for sounding reference signal (SRS) positioning to a reconfigurable intelligent surface (RIS) via the at least one transceiver, and transmit second configuration information identifying resources for sounding reference signal (SRS) positioning to a user equipment (UE) via the at least one transceiver, wherein each of the first configuration information and the second configuration information indicates a number of SRS resources, a time at which the UE transmits an SRS transmission to the RIS, an expected time at which the UE receives a reflection of the SRS transmission from the RIS, an uncertainty in the expected time at which the UE receives a reflection of the SRS transmission from the RIS, an angle of departure (AoD) at which the RIS transmits a reflection of the SRS transmission from the UE, or a combination thereof.

[0011]

[0011] In one aspect, a user equipment (UE) includes means for obtaining configuration information identifying resources for sounding reference signal (SRS) positioning, means for transmitting multiple SRS transmissions to a reconfigurable intelligent surface (RIS) at different times in accordance with the configuration information, means for receiving multiple SRS transmissions from the RIS including reflections of the multiple SRS transmissions to the RIS, each of the multiple SRS transmissions from the RIS being transmitted at a different angle of departure (AoD) from the RIS, means for measuring each of the multiple SRS transmissions from the RIS to generate multiple measurements, and means for performing a positioning operation based on the multiple measurements.

[0012]

[0012] In one aspect, a reconfigurable intelligent surface (RIS) includes means for obtaining configuration information identifying resources for sounding reference signal (SRS) positioning, means for receiving multiple SRS transmissions at different times from a user equipment (UE), and means for transmitting multiple SRS transmissions including reflections of the multiple SRS transmissions received from the UE, each of the multiple SRS transmissions from the RIS being transmitted at a different angle of departure (AoD) from the RIS in accordance with the configuration information.

[0013]

[0013] In one aspect, a location server includes means for transmitting first configuration information to a reconfigurable intelligent surface (RIS) identifying resources for sounding reference signal (SRS) positioning, and means for transmitting second configuration information to a user equipment (UE) identifying resources for sounding reference signal (SRS) positioning, each of the first configuration information and the second configuration information indicating a number of SRS resources, a time at which the UE transmits an SRS transmission to the RIS, an expected time at which the UE will receive a reflection of the SRS transmission from the RIS, an uncertainty in the expected time at which the UE will receive a reflection of the SRS transmission from the RIS, an angle of departure (AoD) at which the RIS transmits a reflection of the SRS transmission from the UE, or a combination thereof.

[0014]

[0014] In one aspect, a non-transitory computer-readable medium stores computer-executable instructions that, when executed by a user equipment (UE), cause the UE to obtain configuration information identifying resources for sounding reference signal (SRS) positioning, cause a reconfigurable intelligent surface (RIS) to transmit multiple SRS transmissions at different times in accordance with the configuration information, receive multiple SRS transmissions from the RIS including reflections of the multiple SRS transmissions to the RIS, where each of the multiple SRS transmissions from the RIS is transmitted at a different angle of departure (AoD) from the RIS, measure each of the multiple SRS transmissions from the RIS to generate multiple measurements, and perform a positioning operation based on the multiple measurements.

[0015]

[0015] In one aspect, a non-transitory computer-readable medium stores computer-executable instructions that, when executed by a reconfigurable intelligent surface (RIS), cause the RIS to obtain configuration information identifying resources for sounding reference signal (SRS) positioning, receive multiple SRS transmissions at different times from a user equipment (UE), and transmit multiple SRS transmissions including reflections of the multiple SRS transmissions received from the UE, where each of the multiple SRS transmissions from the RIS is transmitted at a different angle of departure (AoD) from the RIS in accordance with the configuration information.

[0016]

[0016] In one aspect, a non-transitory computer-readable medium stores computer-executable instructions that, when executed by a location server, cause the location server to transmit to a reconfigurable intelligent surface (RIS) first configuration information identifying resources for sounding reference signal (SRS) positioning and to transmit to a user equipment (UE) second configuration information identifying resources for sounding reference signal (SRS) positioning, each of the first configuration information and the second configuration information indicating a number of SRS resources, a time at which the UE will transmit an SRS transmission to the RIS, an expected time at which the UE will receive a reflection of the SRS transmission from the RIS, an uncertainty in the expected time at which the UE will receive a reflection of the SRS transmission from the RIS, an angle of departure (AoD) at which the RIS transmits a reflection of the SRS transmission from the UE, or a combination thereof.

[0017]

[0017] Other objects and advantages associated with the embodiments disclosed herein will become apparent to those skilled in the art based on the accompanying drawings and detailed description. [Brief description of the drawings]

[0018]

[0018] The accompanying drawings are presented to aid in the explanation of various aspects of the present disclosure and are provided only to illustrate the aspects and not to limit the aspects. [Figure 1]

[0019] FIG. 1 illustrates an example wireless communication system according to an aspect of the present disclosure. [Figure 2A]

[0020] FIG. 1 illustrates an example wireless network structure according to an aspect of the present disclosure. [Figure 2B] FIG. 1 illustrates an example wireless network structure according to an aspect of the present disclosure. [Figure 3A]

[0021] 1 is a simplified block diagram of several sample aspects of components that may be employed in a user equipment (UE) and configured to support communications as taught herein; [Figure 3B] 1 is a simplified block diagram of several sample aspects of components that may be employed in a base station and configured to support communications as taught herein. [Figure 3C] 1 is a simplified block diagram of several sample aspects of components that may be employed in a network entity and configured to support communications as taught herein. [Figure 4A]

[0022] FIG. 2 illustrates an example frame structure and channels within the frame structure in accordance with an aspect of the present disclosure. [Figure 4B] FIG. 2 illustrates an example frame structure and channels within the frame structure in accordance with an aspect of the present disclosure. [Figure 4C] FIG. 2 illustrates an example frame structure and channels within the frame structure in accordance with an aspect of the present disclosure. [Figure 4D] FIG. 2 illustrates an example frame structure and channels within the frame structure in accordance with an aspect of the present disclosure. [Diagram 5]

[0023] FIG. 2 illustrates an exemplary base station communicating with an exemplary UE, in accordance with an aspect of the present disclosure. [Figure 6]

[0024] FIG. 1 illustrates a conventional method for performing DL-AoD measurements using RSRP measurements. [Figure 7]

[0025] 1 is a plot of expected RSRP values ​​as a function of azimuth angle, normalized to remove the effects of distance. [Figure 8]

[0026] FIG. 1 illustrates a conventional system for multi-round trip time (multi-RTT) positioning. [Figure 9]

[0027] A diagram showing a system for multi-RTT positioning using a single gNB. [Figure 10]

[0028] FIG. 10 illustrates a system 1000 for multi-RTT positioning using uplink (UL) sounding reference signals (SRS) and multiple reconfigurable intelligent surfaces (RIS). [Figure 11]

[0029] 1 is a flowchart of an example process associated with RIS beam sweeping of an SRS for angle-of-departure (AoD) based positioning in accordance with an embodiment of the present disclosure. [Figure 12]

[0030] 1 is a flowchart of an example process associated with RIS beam sweeping of an SRS for angle-of-departure (AoD) based positioning in accordance with an embodiment of the present disclosure. [Figure 13A]

[0031] 1 is a flowchart of an example process associated with RIS beam sweeping of an SRS for angle-of-departure (AoD) based positioning in accordance with an embodiment of the present disclosure. [Figure 13B] 1 is a flowchart of an example process associated with RIS beam sweeping of an SRS for angle-of-departure (AoD) based positioning in accordance with an embodiment of the present disclosure. [Figure 14]

[0032] FIG. 1 illustrates an example network that implements UE-based positioning using a single RIS in accordance with certain aspects of the present disclosure. [Figure 15]

[0033] FIG. 13 is a signaling and event diagram for RIS beam sweeping of an SRS for UE-based AoD positioning according to some aspects of the present disclosure. [Figure 16]FIG. 13 is a signaling and event diagram for RIS beam sweeping of an SRS for UE-based AoD positioning according to some aspects of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019]

[0034] Aspects of the present disclosure are provided in the following description and associated drawings, directed to various examples provided for illustrative purposes. Alternative aspects may be devised without departing from the scope of the present disclosure. Additionally, well-known elements of the present disclosure will not be described in detail or will be omitted so as not to obscure the relevant details of the present disclosure.

[0020]

[0035] The words "exemplary" and / or "example" are used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" and / or "example" should not necessarily be construed as preferred or advantageous over other aspects. Likewise, the term "aspects of the present disclosure" does not require that all aspects of the present disclosure include the described feature, advantage or mode of operation.

[0021]

[0036] Those skilled in the art will appreciate that the information and signals described below may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the following description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof, depending in part on the particular application, desired design, corresponding technology, etc.

[0022]

[0037] Further, many aspects are described in terms of sequences of actions to be performed by, for example, elements of a computing device. It will be appreciated that various actions described herein may be performed by specific circuitry (e.g., an application specific integrated circuit (ASIC)), by program instructions executed by one or more processors, or by a combination of both. In addition, a sequence of actions described herein may be considered to be fully embodied in any form of non-transitory computer-readable storage medium having stored thereon a corresponding set of computer instructions that, when executed, cause or instruct an associated processor of a device to perform the functions described herein. Thus, various aspects of the present disclosure may be embodied in a number of different forms, all of which are contemplated to fall within the scope of the claimed subject matter. In addition, for each of the aspects described herein, the corresponding form of any such aspect may be described herein, for example, as "logic configured to" perform the described actions.

[0023]

[0038] The terms "user equipment" (UE) and "base station" as used herein are not intended to be specific or otherwise limited to any particular radio access technology (RAT) unless otherwise specified. In general, a UE may be any wireless communication device (e.g., a mobile phone, a router, a tablet computer, a laptop computer, a consumer location device, a wearable (e.g., a smart watch, glasses, an augmented reality (AR) / virtual reality (VR) headset, etc.), a vehicle (e.g., a car, a motorcycle, a bicycle, etc.), an Internet of Things (IoT) device, etc.) used by a user to communicate over a wireless communication network. A UE may be mobile or stationary (e.g., at some time) and may communicate with a radio access network (RAN). The term "UE" as used herein may be referred to interchangeably as an "access terminal" or "AT", "client device", "wireless device", "subscriber device", "subscriber terminal", "subscriber station", "user terminal" or "UT", "mobile device", "mobile terminal", "mobile station", or variations thereof. In general, a UE may communicate with a core network via the RAN, through which the UE may be connected to external networks, such as the Internet, and to other UEs. Of course, other mechanisms for connecting to the core network and / or the Internet are also possible for a UE, such as via a wired access network, a Wireless Local Area Network (WLAN) network (e.g., based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 specifications, etc.).

[0024]

[0039] A base station may operate according to one of several RATs in communication with UEs depending on the network in which the base station is deployed and may alternatively be referred to as an access point (AP), network node, NodeB (NodeB), evolved NodeB (eNB), next generation eNB (ng-eNB), New Radio (NR) NodeB (also referred to as gNB or gNodeB), etc. A base station may be primarily used to support wireless access by UEs, including supporting data, voice, and / or signaling connections for supported UEs. In some systems, a base station may provide only edge node signaling functionality, while in other systems, a base station may provide additional control and / or network management functionality. A communication link through which a UE may send signals to a base station is referred to as an uplink (UL) channel (e.g., a reverse traffic channel, a reverse control channel, an access channel, etc.). A communication link through which a base station may send signals to a UE is referred to as a downlink (DL) or forward link channel (e.g., a paging channel, a control channel, a broadcast channel, a forward traffic channel, etc.). The term Traffic Channel (TCH) as used herein can refer to either an uplink / reverse traffic channel or a downlink / forward traffic channel.

[0025]

[0040] The term "base station" may refer to a single physical transmission-reception point (TRP) or multiple physical TRPs that may or may not be collocated. For example, when the term "base station" refers to a single physical TRP, the physical TRP may be an antenna of the base station that corresponds to a cell (or several cell sectors) of the base station. When the term "base station" refers to multiple collocated physical TRPs, the physical TRP may be an array of antennas of the base station (e.g., as in the case of a multiple-input multiple-output (MIMO) system or when the base station employs beamforming). When the term "base station" refers to multiple non-collocated physical TRPs, the physical TRP may be a distributed antenna system (DAS) (a network of spatially separated antennas connected to a common source via a transport medium) or a remote radio head (RRH) (a remote base station connected to a serving base station). Alternatively, non-co-located physical TRPs may be serving base stations that receive measurement reports from the UE and neighboring base stations whose reference radio frequency (RF) signals the UE is measuring. Since a TRP is a point from which a base station transmits and receives wireless signals, as used herein, references to transmission from or reception at a base station should be understood as referring to a particular TRP of the base station.

[0026]

[0041] In some implementations that support positioning of UEs, a base station may not support wireless access by the UE (e.g., may not support data, voice, and / or signaling connections for the UE) but may instead transmit reference signals to the UE to be measured by the UE and / or receive and measure signals transmitted by the UE. Such a base station may be referred to as a positioning beacon (e.g., when it transmits signals to the UE) and / or a position measurement unit (e.g., when it receives and measures signals from the UE).

[0027]

[0042] An "RF signal" includes electromagnetic waves of a given frequency that transport information through space between a transmitter and a receiver. As used herein, a transmitter may transmit a single "RF signal" or multiple "RF signals" to a receiver. However, the receiver may receive multiple "RF signals" corresponding to each transmitted RF signal due to the propagation characteristics of RF signals through a multipath channel. The same transmitted RF signal on different paths between a transmitter and a 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" when it is clear from the context that the term "signal" refers to a wireless signal or an RF signal.

[0028]

[0043] 1 illustrates an example wireless communication system 100 according to an aspect of the disclosure. The wireless communication system 100 (sometimes referred to as a wireless wide area network (WWAN)) may include various base stations 102 (labeled "BS") and various UEs 104. The base stations 102 may include macrocell base stations (high-power cellular base stations) and / or small cell base stations (low-power cellular base stations). In an aspect, the macrocell base stations may include eNBs and / or ng-eNBs where the wireless communication system 100 corresponds to an LTE network, or gNBs where the wireless communication system 100 corresponds to an NR network, or a combination of both, and the small cell base stations may include femtocells, picocells, microcells, etc.

[0029]

[0044] The base stations 102 may collectively form a RAN and may interface with a core network 170 (e.g., Evolved Packet Core (EPC) or 5G Core (5GC)) through the backhaul links 122 and with one or more location servers 172 (e.g., Location Management Function (LMF) or Secure User Plane Location (SUPL) Location Platform (SLP)) through the core network 170. The location servers 172 may be part of the core network 170 or may be external to the core network 170. The UE 104 may communicate with the location server 172 directly or indirectly. For example, the UE 104 may communicate with the location server 172 through a base station 102 currently serving the UE 104. The UE 104 may also communicate with the location server 172 through another path, such as through an application server, through another network, such as through a Wi-Fi access point, and so on. For signaling purposes, communication between the UE 104 and the location server 172 may be represented as a direct connection with intervening nodes (if any) omitted from the signaling diagrams for clarity.

[0030]

[0045] In addition to other functions, the base stations 102 may perform functions related to one or more of the following: forwarding user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, non-access stratum (NAS) message delivery, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment tracing, RAN information management (RIM), paging, positioning, and alert message delivery. The base stations 102 may communicate with each other directly or indirectly (e.g., through EPC / 5GC) via backhaul links 134, which may be wired or wireless.

[0031]

[0046] The base stations 102 may wirelessly communicate with the UEs 104. Each of the base stations 102 may provide communication coverage to a respective geographic coverage area 110. In an aspect, one or more cells may be supported by the base stations 102 in each geographic coverage area 110. A "cell" is a logical communication entity used for communication with a base station (e.g., over some frequency resources, referred to as a carrier frequency, component carrier, carrier, band, etc.) and may be associated with an identifier (e.g., physical cell identifier (PCI), enhanced cell identifier (ECI), virtual cell identifier (VCI), cell global identifier (CGI), etc.) to distinguish cells operating over the same or different carrier frequencies. In some cases, different cells may be configured according to different protocol types (e.g., machine-type communication (MTC), narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB), or others) that may provide access for different types of UEs. Since a cell is supported by a particular base station, the term "cell" may refer to one or both of the logical communication entity and the base station that supports it, depending on the context. In addition, since a TRP is typically a 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 the geographic coverage area (e.g., sector) of a base station, as long as the carrier frequency can be detected and used for communication within a portion of the geographic coverage area 110.

[0032]

[0047] The geographic coverage areas 110 of neighboring macrocell base stations 102 may overlap partially (e.g., in handover regions) and some of the geographic coverage areas 110 may be substantially overlapped by larger geographic coverage areas 110. For example, a small cell base station 102' (labeled "SC" instead of "small cell") may have a geographic coverage area 110' that significantly overlaps with the geographic coverage area 110 of one or more macrocell base stations 102. A network that includes both small cell base stations and macrocell base stations may be known as a heterogeneous network. A heterogeneous network may also include home eNBs (HeNBs), which may serve closed groups known as closed subscriber groups (CSGs).

[0033]

[0048] The communication link 120 between the base station 102 and the UE 104 may include uplink (also referred to as reverse link) transmissions from the UE 104 to the base station 102, and / or downlink (DL) (also referred to as forward link) transmissions from the base station 102 to the UE 104. The communication link 120 may use MIMO antenna techniques, including spatial multiplexing, beamforming, and / or transmit diversity. The communication link 120 may be through one or more carrier frequencies. The allocation of carriers may be asymmetric with respect to the downlink and uplink (e.g., more or fewer carriers may be allocated for the downlink than for the uplink).

[0034]

[0049] The wireless communication system 100 may further include a wireless local area network (WLAN) access point (AP) 150 in communication with a wireless local area network (WLAN) station (STA) 152 over a communication link 154 in an unlicensed frequency spectrum (e.g., 5 GHz). When communicating in the unlicensed frequency spectrum, the WLAN STA 152 and / or the WLAN AP 150 may perform a clear channel assessment (CCA) or listen before talk (LBT) procedure before communicating to determine if a channel is available.

[0035]

[0050] The small cell base station 102' may operate in a licensed and / or unlicensed frequency spectrum. When operating in the unlicensed frequency spectrum, the small cell base station 102' may utilize LTE or NR technology and use the same 5 GHz unlicensed frequency spectrum used by the WLAN AP 150. A small cell base station 102' employing LTE / 5G in the unlicensed frequency spectrum may extend coverage to and / or increase capacity of the access network. NR in the unlicensed spectrum may be referred to as NR-U. LTE in the unlicensed spectrum may be referred to as LTE-U, licensed assisted access (LAA), or MultiFire.

[0036]

[0051] The wireless communication system 100 may further include a millimeter wave (mmW) base station 180 that may operate in mmW and / or sub-mmW frequencies in communication with the UE 182. Extremely high frequency (EHF) is a portion of RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength of 1 millimeter to 10 millimeters. Radio waves in this band may be referred to as millimeter waves. Sub-mmW may extend down to frequencies of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and 30 GHz and is also referred to as centimeter waves. Communications using the mmW / sub-mmW radio frequency bands have high path losses and relatively short distances. The mmW base station 180 and the UE 182 may utilize beamforming (transmit and / or receive) over the mmW communication link 184 to compensate for the extremely large path losses and short distances. Further, it will be appreciated that in alternative configurations, one or more base stations 102 may also transmit using mmW or quasi-mmW and beamforming. Thus, it will be appreciated that the above illustrations are merely examples and should not be construed as limiting various aspects disclosed herein.

[0037]

[0052] Transmit beamforming is a technique for focusing an RF signal in a particular direction. Traditionally, when a network node (e.g., a base station) broadcasts an RF signal, it broadcasts the signal in all directions (omnidirectionally). With transmit beamforming, the network node determines where a given target device (e.g., UE) is located (relative to the transmitting network node) and projects a stronger downlink RF signal in that particular direction, thereby providing a faster and more powerful RF signal (in terms of data rate) to the receiving device. To vary the directionality of the RF signal when transmitting, the network node can control the phase and relative amplitude of the RF signal at each of one or more transmitters broadcasting the RF signal. For example, the network node can use an array of antennas (also called a "phased array" or "antenna array") that creates beams of RF waves that can be "steered" to point in different directions without actually moving the antennas. In particular, RF current from a transmitter is supplied to each antenna with the proper phase relationship so that the radio waves from the separate antennas combine together to enhance radiation in the desired direction while suppressing and canceling radiation in undesired directions.

[0038]

[0053] A transmit beam may be quasi-co-located, meaning that the transmit beam appears to a receiver (e.g., UE) to have the same parameters, regardless of whether the network node's own transmit antennas are physically co-located or not. In NR, there are four types of quasi-co-location (QCL) relationships. Specifically, a QCL relationship of a given type means that some parameters for a second reference RF signal on a second beam can be derived from information about a source reference RF signal on a source beam. Thus, if the source reference RF signal is QCL type A, the receiver can use the source reference RF signal to estimate the Doppler shift, Doppler spread, average delay, and delay spread of the second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL type B, the receiver can use the source reference RF signal to estimate the Doppler shift and Doppler spread of the second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type C, the receiver can use the source reference RF signal to estimate the Doppler shift and average delay of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type D, the receiver can use the source reference RF signal to estimate spatial reception parameters of a second reference RF signal transmitted on the same channel.

[0039]

[0054] In receive beamforming, a receiver uses receive beams to amplify RF signals detected on a given channel. For example, the receiver can increase the gain setting and / or adjust the phase setting of an array of antennas in a particular direction to amplify (e.g., increase the gain level) RF signals received from that direction. Thus, when a receiver is said to beamform in some direction, it means that the beam gain in that direction is higher than the beam gains along other directions, or that the beam gain in that direction is the highest compared to the beam gains in that direction of all other receive beams available to the receiver. This results in a stronger received signal strength (e.g., reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-interference-plus-noise ratio (SINR), etc.) of RF signals received from that direction.

[0040]

[0055] The transmit beam and the receive beam may be spatially related. The spatial relationship means that the parameters for the second beam (e.g., transmit beam or receive beam) for the second reference signal may be derived from information about the first beam (e.g., receive beam or transmit beam) for the first reference signal. For example, the UE may use a particular receive beam to receive a reference downlink reference signal (e.g., synchronization signal block (SSB)) from a base station. The UE may then form a transmit beam for transmitting an uplink reference signal (e.g., sounding reference signal (SRS)) to that base station based on the parameters of the receive beam.

[0041]

[0056] Note that a "downlink" beam can be either a transmit beam or a receive beam, depending on the entity that forms it. For example, if the base station forms a downlink beam to transmit a reference signal to the UE, then the downlink beam is a transmit beam. However, if the UE forms a downlink beam, then it is a receive beam to receive a downlink reference signal. Similarly, an "uplink" beam can be either a transmit beam or a receive beam, depending on the entity that forms it. For example, if the base station forms an uplink beam, then it is an uplink receive beam, and if the UE forms an uplink beam, then it is an uplink transmit beam.

[0042]

[0057] In 5G, the frequency spectrum in which wireless nodes (e.g., base stations 102 / 180, UEs 104 / 182) operate is divided into multiple frequency ranges: FR1 (450-6000 MHz), FR2 (24250-52600 MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). The mmW frequency band generally includes the FR2, FR3, and FR4 frequency ranges. Thus, the terms "mmW" and "FR2" or "FR3" or "FR4" may generally be used interchangeably.

[0043]

[0058] In a multi-carrier system such as 5G, one of the carrier frequencies is called the "primary carrier" or "anchor carrier" or "primary serving cell" or "PCell" and the remaining carrier frequencies are called the "secondary carrier" or "secondary serving cell" or "SCell". In carrier aggregation, the anchor carrier is a carrier operating on the primary frequency (e.g., FR1) utilized by the UE 104 / 182 and on the cell in which the UE 104 / 182 either performs an initial radio resource control (RRC) connection establishment procedure or initiates an RRC connection re-establishment procedure. The primary carrier carries all common control channels and UE-specific control channels and may be (but is not always) a carrier among licensed frequencies. The secondary carrier is a carrier operating on a second frequency (e.g., FR2) that may be configured once an RRC connection is established between the UE 104 and the anchor carrier and may be used to provide additional radio resources. In some cases, the secondary carrier may be a carrier in unlicensed frequencies. Since both the primary uplink carrier and the primary downlink carrier are typically UE specific, the secondary carrier may include only the necessary signaling information and signals, e.g., the signaling information and signals that are UE specific may not be present in the secondary carrier. This means that different UEs 104 / 182 in a cell may have different downlink primary carriers. The same applies to the uplink primary carrier. The network may change the primary carrier of any UE 104 / 182 at any time. This is done, for example, to distribute the load on different carriers. Since a "serving cell" (whether PCell or SCell) corresponds to a carrier frequency / component carrier over which several base stations are communicating, terms such as "cell", "serving cell", "component carrier", "carrier frequency", etc. may be used interchangeably.

[0044]

[0059] For example, still referring to FIG. 1, one of the frequencies utilized by the macrocell base station 102 may be an anchor carrier (or “PCell”), and the other frequencies utilized by the macrocell base station 102 and / or the mmW base station 180 may be secondary carriers (“SCells”). Simultaneous transmission and / or reception of multiple carriers allows the UE 104 / 182 to significantly increase its data transmission and / or data reception rates. For example, two aggregated 20 MHz carriers in a multi-carrier system would theoretically lead to a two-fold increase in data rate (i.e., 40 MHz) compared to the data rate achieved by a single 20 MHz carrier.

[0045]

[0060] The wireless communications system 100 may further include a UE 164, which may communicate with the macrocell base station 102 via communications link 120 and / or with the mmW base station 180 via mmW communications link 184. For example, the macrocell base station 102 may support a PCell and one or more SCells for the UE 164, and the mmW base station 180 may support one or more SCells for the UE 164.

[0046]

[0061] In the example of FIG. 1, one or more Earth-orbiting satellite positioning system (SPS) space vehicles (SVs) 112 (e.g., satellites) may be used as independent sources of location information for any of the illustrated UEs (shown in FIG. 1 as a single UE 104 for simplicity). The UE 104 may include one or more dedicated SPS receivers specifically designed to receive SPS signals 124 to derive geolocation information from the SVs 112. An SPS typically includes a system of transmitters (e.g., SVs 112) positioned to enable receivers (e.g., UEs 104) to determine their position on or above the Earth based at least in part on signals (e.g., SPS signals 124) received from the transmitters. Such transmitters typically transmit signals marked with a repeating pseudo-random noise (PN) code of a set number of chips. Although typically located within the SV 112, the transmitters may sometimes be located on ground-based control stations, base stations 102, and / or other UEs 104.

[0047]

[0062] Use of the SPS signals 124 may be augmented by various satellite-based augmentation systems (SBAS) that may be associated with or otherwise enabled for use with one or more global and / or regional navigation satellite systems. For example, the SBAS may include augmentation systems that provide integrity information, differential corrections, and the like, such as the Wide Area Augmentation System (WAAS), the European Geostationary Navigation Overlay Service (EGNOS), the Multi-functional Satellite Augmentation System (MSAS), the Global Positioning System (GPS)-aided Geo-augmented Navigation, or the GPS and Geo Augmented Navigation system (GAGAN). Thus, as used herein, an SPS may include any combination of one or more global and / or regional navigation satellite systems and / or augmentation systems, and SPS signals 124 may include SPS, SPS-like signals, and / or other signals related to such one or more SPSs.

[0048]

[0063] The wireless communication system 100 may further include one or more UEs, such as UE 190, that indirectly connect to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links (referred to as "sidelinks"). In the example of FIG. 1, the UE 190 has a D2D P2P link 192 (e.g., through which the UE 190 may indirectly obtain cellular connectivity) with one of the UEs 104 connected to one of the base stations 102, and a D2D P2P link 194 (through which the UE 190 may indirectly obtain WLAN-based Internet connectivity) with a WLAN STA 152 connected to a WLAN AP 150. In one example, the D2D P2P links 192 and 194 may be supported using any well-known D2D RAT, such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), Bluetooth, etc.

[0049]

[0064] 2A illustrates an exemplary wireless network structure 200. For example, a 5GC 210 (also referred to as Next Generation Core (NGC)) may be considered functionally as control plane (C-plane) functions 214 (e.g., UE registration, authentication, network access, gateway selection, etc.) and user plane (U-plane) functions 212 (e.g., UE gateway functions, access to data networks, IP routing, etc.) that operate cooperatively to form a core network. A user plane interface (NG-U) 213 and a control plane interface (NG-C) 215 connect the gNB 222 to the 5GC 210, specifically to the user plane function 212 and the control plane function 214, respectively. In an additional configuration, the ng-eNB 224 may also be connected to the 5GC 210 via the NG-C 215 to the control plane function 214 and the NG-U 213 to the user plane function 212. Additionally, the ng-eNB 224 may communicate directly with the gNB 222 via a backhaul connection 223. In some configurations, the Next Generation RAN (NG-RAN) 220 may have one or more gNBs 222, while other configurations include one or more of both the ng-eNB 224 and the gNB 222. Either the gNB 222 or the ng-eNB 224 (or both) may communicate with one or more UEs 204 (e.g., any of the UEs described herein).

[0050]

[0065] Another optional aspect may include a location server 230, which may be in communication with the 5GC 210 to provide location assistance to the UE 204. The location servers 230 may be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules across multiple physical servers, etc.), or alternatively, each may correspond to a single server. The location server 230 may be configured to support one or more location services for the UE 204 that may connect to the location server 230 via the core network 5GC 210 and / or via the Internet (not shown). Furthermore, the location server 230 may be incorporated into a component of the core network, or may alternatively be external to the core network (e.g., a third-party server, such as an original equipment manufacturer (OEM) server or a service server).

[0051]

[0066] 2B illustrates another exemplary wireless network structure 250. A 5GC 260 (which may correspond to 5GC 210 in FIG. 2A) may be considered functionally as control plane functions provided by an access and mobility management function (AMF) 264 and user plane functions provided by a user plane function (UPF) 262, which operate cooperatively to form a core network (i.e., 5GC 260). The functions of the AMF 264 include registration management, connection management, reachability management, mobility management, lawful interception, transport for session management (SM) messages between one or more UEs 204 (e.g., any of the UEs described herein) and a session management function (SMF) 266, transparent proxy services for routing SM messages, access authentication and access authorization, transport for short message service (SMS) messages between the UE 204 and a short message service function (SMSF) (not shown), and security anchor functionality (SEAF). The AMF 264 also interacts with an authentication server function (AUSF) (not shown) and the UE 204 to receive intermediate keys established as a result of the UE 204 authentication process. In case of UMTS (universal mobile telecommunications system) subscriber identity module (USIM) based authentication, the AMF 264 retrieves security material from the AUSF. The AMF 264 functionality also includes security context management (SCM). The SCM receives keys from the SEAF that the SCM uses to derive access network specific keys.The functionality of the AMF 264 also includes location service management for regulated services, transport for location service messages between the UE 204 and the Location Management Function (LMF) 270 (acting as the location server 230), transport for location service messages between the NG-RAN 220 and the LMF 270, Evolved Packet System (EPS) bearer identifier allocation for interworking with EPS, and UE 204 mobility event notification. In addition, the AMF 264 also supports functions for non-3GPP (Third Generation Partnership Project) access networks.

[0052]

[0067] The functions of the UPF 262 include acting as an anchor point for intra / inter-RAT mobility (when applicable), acting as an external protocol data unit (PDU) session point for interconnection to a data network (not shown), routing and forwarding of packets, 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 validation (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 one or more "end markers" to the source RAN node. The UPF 262 may also support forwarding of location service messages on the user plane between the UE 204 and a location server such as the SLP 272.

[0053]

[0068] The functions of the SMF 266 include session management, UE Internet protocol (IP) address allocation and management, selection and control of user plane functions, configuration of traffic steering in the UPF 262 to route traffic to the appropriate destination, control of policy enforcement and part of QoS, and downlink data notification. The interface through which the SMF 266 communicates with the AMF 264 is called the N11 interface.

[0054]

[0069] Another optional aspect may include an LMF 270, which may be in communication with the 5GC 260 to provide location assistance to the UE 204. The LMF 270 may be implemented as multiple separate servers (e.g., physically separate servers, different software modules on a single server, different software modules across multiple physical servers, etc.), or alternatively, each may represent a single server. The LMF 270 may be configured to support one or more location services for the UE 204, which may be connected to the LMF 270 via a core network, the 5GC 260, and / or via the Internet (not shown). The SLP 272 may support similar functions as the LMF 270, except that the LMF 270 may communicate with the AMF 264, the NG-RAN 220, and the UE 204 on the control plane (e.g., using interfaces and protocols intended to carry signaling messages rather than voice or data), and the SLP 272 may communicate with the UE 204 and external clients (not shown in FIG. 2B) on the user plane (e.g., using protocols intended to carry voice and / or data, such as Transmission Control Protocol (TCP) and / or IP).

[0055]

[0070] The user plane interface 263 and the control plane interface 265 connect the 5GC 260, in particular the UPF 262 and the AMF 264, to one or more gNBs 222 and / or ng-eNBs 224 in the NG-RAN 220, respectively. The interface between the gNBs 222 and / or ng-eNBs 224 and the AMF 264 is referred to as the "N2" interface, and the interface between the gNBs 222 and / or ng-eNBs 224 and the UPF 262 is referred to as the "N3" interface. The gNBs 222 and / or ng-eNBs 224 of the NG-RAN 220 may communicate directly with each other via a backhaul connection 223 referred to as the "Xn-C" interface. One or more of the gNBs 222 and / or ng-eNBs 224 may communicate with one or more UEs 204 via a wireless interface referred to as the "Uu" interface.

[0056]

[0071] The functionality of the gNB 222 is divided between a gNB Central Unit (gNB-CU) 226 and one or more gNB Distributed Units (gNB-DU) 228. The interface 232 between the gNB-CU 226 and one or more gNB-DUs 228 is called the "F1" interface. The gNB-CU 226 is a logical node that includes base station functions such as forwarding user data, mobility control, radio access network sharing, positioning, session management, etc., except for those functions exclusively allocated to the gNB-DU 228. More specifically, the gNB-CU 226 hosts the Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), and Packet Data Convergence Protocol (PDCP) protocols of the gNB 222. The gNB-DU 228 is a logical node that hosts the Radio Link Control (RLC), Medium Access Control (MAC), and Physical (PHY) layers of the gNB 222. Its operation is controlled by the gNB-CU 226. One gNB-DU 228 can support one or multiple cells, and one cell is supported by only one gNB-DU 228. Thus, the UE 204 communicates with the gNB-CU 226 via the RRC, SDAP, and PDCP layers, and with the gNB-DU 228 via the RLC, MAC, and PHY layers.

[0057]

[0072] 3A, 3B, and 3C illustrate some example components (represented by corresponding blocks) that may be incorporated in device 302 (corresponding to any of the UEs described herein and therefore may also be referred to as UE 302), device 304 (corresponding to any of the base stations or RISs described herein and therefore may also be referred to as BS 304 or RIS 304), and device 306 (which may correspond to or embody any of the network functions described herein, including location server 230 and LMF 270 and therefore may also be referred to as network entity 306, LS 306, or LMF 306, or may be separate from the NG-RAN 220 and / or 5GC 210 / 260 infrastructure shown in FIGS. 2A and 2B, such as a private network) to support file transmission operations taught herein. The device shown in FIG. 3B, or a simplified version thereof, may be a reconfigurable intelligent surface (RIS). It will be understood that these components may be implemented in different implementations (e.g., in an ASIC, in a system on a chip (SoC), etc.) and in different types of devices. The illustrated components may also be incorporated into other devices in a communication system. For example, other devices in the system may include components similar to the illustrated components to provide similar functionality. Also, a given device may include one or more of the components. For example, a device may include multiple transceiver components that enable the device to operate on multiple carriers and / or communicate via different technologies.

[0058]

[0073] The UE 302 and base station 304 each include one or more wireless wide area network (WWAN) transceivers 310 and 350, respectively, providing means for communicating (e.g., means for transmitting, means for receiving, means for measuring, means for tuning, means for refraining from transmitting, etc.) over one or more wireless communications networks (not shown), such as an NR network, an LTE network, a GSM network, etc. The WWAN transceivers 310 and 350 may each be connected to one or more antennas 316 and 356, respectively, for communicating with other network nodes, such as other UEs, access points, base stations (e.g., eNBs, gNBs), etc., over at least one designated RAT (e.g., NR, LTE, GSM, etc.) over a wireless communications medium of interest (e.g., some set of time / frequency resources in a particular frequency spectrum). The WWAN transceivers 310 and 350 may be variously configured to transmit and encode signals 318 and 358, respectively (e.g., messages, instructions, information, etc.), and conversely, to receive and decode signals 318 and 358, respectively (e.g., messages, instructions, information, pilots, etc.), in accordance with a designated RAT. In particular, the WWAN transceivers 310 and 350 include one or more transmitters 314 and 354, respectively, to transmit and encode signals 318 and 358, respectively, and include one or more receivers 312 and 352, respectively, to receive and decode signals 318 and 358, respectively.

[0059]

[0074] The UE 302 and base station 304 also each, at least in some cases, include one or more short-range wireless transceivers 320 and 360, respectively. The short-range wireless transceivers 320 and 360 may be connected to one or more antennas 326 and 366, respectively, and may provide means for communicating (e.g., means for transmitting, means for receiving, means for measuring, means for tuning, means for refraining from transmitting, etc.) with other network nodes, such as other UEs, access points, base stations, etc., via at least one designated RAT (e.g., WiFi, LTE-D, Bluetooth, Zigbee, Z-Wave, PC5, Dedicated Short-Range Communications (DSRC), wireless access for vehicular environments (WAVE), Near Field Communication (NFC), etc.) over a wireless communication medium of interest. The short-range wireless transceivers 320 and 360 may be variously configured to transmit and encode signals 328 and 368, respectively (e.g., messages, instructions, information, etc.), and conversely, to receive and decode signals 328 and 368, respectively (e.g., messages, instructions, information, pilots, etc.), in accordance with a specified RAT. In particular, the short-range wireless transceivers 320 and 360 include one or more transmitters 324 and 364, respectively, to transmit and encode signals 328 and 368, respectively, and include one or more receivers 322 and 362, respectively, to receive and decode signals 328 and 368, respectively. As specific examples, the short-range wireless transceivers 320 and 360 may be WiFi transceivers, Bluetooth® transceivers, Zigbee® and / or Z-Wave® transceivers, NFC transceivers, or Vehicle-to-Vehicle (V2V) and / or Vehicle-to-Everything (V2X) transceivers.

[0060]

[0075] The UE 302 and base station 304 also, at least in some cases, include satellite positioning system (SPS) receivers 330 and 370. The SPS receivers 330 and 370 may be connected to one or more antennas 336 and 376, respectively, and may provide a means for receiving and / or measuring SPS signals 338 and 378, respectively, such as Global Positioning System (GPS) signals, Global Navigation Satellite System (GLONASS) signals, Galileo signals, Beidou signals, Navigation Satellite System of India (NAVIC), Quasi-Zenith Satellite System (QZSS), etc. The SPS receivers 330 and 370 may comprise any suitable hardware and / or software for receiving and processing the SPS signals 338 and 378, respectively. The SPS receivers 330 and 370 appropriately request information and actions from other systems and perform the necessary calculations to determine the position of the UE 302 and base station 304 using the measurements obtained by any suitable SPS algorithms.

[0061]

[0076] The base station 304 and the network entity 306 each include one or more network transceivers 380 and 390, respectively, that provide a means for communicating (e.g., a means for transmitting, a means for receiving, etc.) with other network entities (e.g., other base stations 304, other network entities 306). For example, the base station 304 may employ one or more network transceivers 380 to communicate with other base stations 304 or network entities 306 over one or more wired or wireless backhaul links. As another example, the network entity 306 may employ one or more network transceivers 390 to communicate with one or more base stations 304 over one or more wired or wireless backhaul links or with other network entities 306 over one or more wired or wireless core network interfaces.

[0062]

[0077] A transceiver may be configured to communicate over a wired link or a wireless link. A transceiver (whether a wired transceiver or a wireless transceiver) includes transmitter circuitry (e.g., transmitters 314, 324, 354, 364) and receiver circuitry (e.g., receivers 312, 322, 352, 362). A transceiver may be an integrated device (e.g., embodying transmitter and receiver circuitry in a single device) in some implementations, may comprise separate transmitter circuitry and separate receiver circuitry in some implementations, or may be embodied in other ways in other implementations. The transmitter and receiver circuitry of a wired transceiver (e.g., network transceivers 380 and 390 in some implementations) may be coupled to one or more wired network interface ports. The wireless transmitter circuitry (e.g., transmitters 314, 324, 354, 364) may include or be coupled to multiple antennas (e.g., antennas 316, 326, 356, 366), such as an antenna array that enables the respective device (e.g., UE 302, base station 304) to perform transmit "beamforming," as described herein. Similarly, the wireless receiver circuitry (e.g., receivers 312, 322, 352, 362) may include or be coupled to multiple antennas (e.g., antennas 316, 326, 356, 366), such as an antenna array that enables the respective device (e.g., UE 302, base station 304) to perform receive beamforming, as described herein. In one aspect, the transmitter circuitry and the receiver circuitry may share multiple identical antennas (e.g., antennas 316, 326, 356, 366), such that the respective device can only receive or transmit at a given time, but not both at the same time. The wireless transceivers (eg, WWAN transceivers 310 and 350, short range wireless transceivers 320 and 360) may also include network listen modules (NLMs) and the like for performing various measurements.

[0063]

[0078] As used herein, various wireless transceivers (e.g., transceivers 310, 320, 350, and 360, and network transceivers 380 and 390, in some implementations) and wired transceivers (e.g., network transceivers 380 and 390, in some implementations) may be generally characterized as a "transceiver," "at least one transceiver," or "one or more transceivers." Thus, whether a particular transceiver is a wired or wireless transceiver may be inferred from the type of communication being performed. For example, backhaul communications between network devices or servers generally involve signaling via wired transceivers, while wireless communications between a UE (e.g., UE 302) and a base station (e.g., base station 304) generally involve signaling via wireless transceivers.

[0064]

[0079] The UE 302, base station 304, and network entity 306 also include other components that may be used in conjunction with operations as disclosed herein. The UE 302, base station 304, and network entity 306 each include one or more processors 332, 384, and 394, for example, to provide functionality related to wireless communications and to provide other processing functionality. Thus, the processors 332, 384, and 394 may comprise processing means, such as means for determining, means for calculating, means for receiving, means for transmitting, means for indicating, etc. In one aspect, the processors 332, 384, and 394 may include, for example, one or more general purpose processors, multi-core processors, central processing units (CPUs), ASICs, digital signal processors (DSPs), field programmable gate arrays (FPGAs), other programmable logic devices or processing circuits, or various combinations thereof.

[0065]

[0080] The UE 302, base station 304, and network entity 306 each include memory circuitry implementing memories 340, 386, and 396 (e.g., each including a memory device) for maintaining information (e.g., information indicating reserved resources, thresholds, parameters, etc.). Thus, the memories 340, 386, and 396 may comprise storage means, retrieval means, maintaining means, etc. In some cases, the UE 302, base station 304, and network entity 306 may each include AoD components 342, 388, and 398. The AoD components 342, 388, and 398 may be hardware circuits that are part of or coupled to the processors 332, 384, and 394, respectively, which, when executed, cause the UE 302, base station 304, and network entity 306 to perform the functions described herein. In other aspects, the AoD components 342, 388, and 398 may be external to the processors 332, 384, and 394 (e.g., part of a modem processing system, integrated with another processing system, etc.). Alternatively, the AoD components 342, 388, and 398 may be memory modules stored in the memories 340, 386, and 396, respectively, which when executed by the processors 332, 384, and 394 (or a modem processing system, another processing system, etc.), cause the UE 302, the base station 304, and the network entity 306 to perform the functions described herein. Figure 3A illustrates possible locations of the AoD component 342, which may be part of, for example, one or more WWAN transceivers 310, the memory 340, the one or more processors 332, or any combination thereof, or may be a stand-alone component. FIG. 3B shows possible locations for an AoD component 388, which may be, for example, part of one or more WWAN transceivers 350, memory 386, one or more processors 384, or any combination thereof, or may be a stand-alone component.FIG. 3C shows possible locations for an AoD component 398, which may be, for example, part of one or more network transceivers 390, memory 396, one or more processors 394, or any combination thereof, or which may be a stand-alone component.

[0066]

[0081] The UE 302 may include one or more sensors 344 coupled to the one or more processors 332 to provide a means for sensing or detecting movement and / or orientation information that is independent of movement data derived from signals received by the one or more WWAN transceivers 310, the one or more short-range wireless transceivers 320, and / or the SPS receiver 330. By way of example, the sensors 344 may include an accelerometer (e.g., a microelectromechanical system (MEMS) device), a gyroscope, a geomagnetic sensor (e.g., a compass), an altimeter (e.g., a barometric altimeter), and / or any other type of movement detection sensor. Additionally, the sensors 344 may include multiple different types of devices and combine their outputs to provide movement information. For example, the sensors 344 may use a combination of a multi-axis accelerometer and an orientation sensor to provide the ability to calculate a position in a two-dimensional (2D) and / or three-dimensional (3D) coordinate system.

[0067]

[0082] Additionally, the UE 302 includes a user interface 346 that provides a means for providing indications to a user (e.g., audio and / or visual indications) and / or receiving user input (e.g., upon user actuation of a sensing device, such as a keypad, touch screen, microphone, etc.). Although not shown, the base station 304 and the network entity 306 may also include user interfaces.

[0068]

[0083] Referring more particularly to the one or more processors 384, on the downlink, IP packets from the network entity 306 may be provided to the processor 384. The one or more processors 384 may implement functionality for an RRC layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, and a Medium Access Control (MAC) layer. The one or more processors 384 may provide RRC layer functions associated with broadcast of system information (e.g., Master Information Block (MIB), System Information Block (SIB)), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-RAT mobility, and measurement configuration for UE measurement reporting; PDCP layer functions related to header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functions related to transfer of upper layer PDUs, error correction with automatic repeat request (ARQ), concatenation, segmentation, and reassembly of RLC service data units (SDUs), resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions related to mapping between logical channels and transport channels, scheduling information reporting, error correction, priority handling, and logical channel prioritization.

[0069]

[0084] The transmitter 354 and receiver 352 may implement Layer 1 (L1) functions related to various signal processing functions. Layer 1, including the physical (PHY) layer, may include error detection on the transport channel, forward error correction (FEC) encoding / decoding of the transport channel, interleaving, rate matching, mapping onto the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The transmitter 354 handles mapping to signal constellations based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-ary quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an orthogonal frequency division multiplexing (OFDM) subcarrier, multiplexed with reference signals (e.g., pilots) in the time and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to generate a physical channel carrying the time-domain OFDM symbol stream. The OFDM symbol stream is spatially precoded to generate multiple spatial streams. Channel estimates from a channel estimator may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimates may be derived from a reference signal and / or channel condition feedback transmitted by the UE 302. Each spatial stream may then be provided to one or more different antennas 356. The transmitter 354 may modulate an RF carrier with each spatial stream for transmission.

[0070]

[0085] At the UE 302, the receiver 312 receives the signal through its respective antenna 316. The receiver 312 recovers the information modulated onto the RF carriers and provides the information to one or more processors 332. The transmitter 314 and the receiver 312 implement layer 1 functions associated with various signal processing functions. The receiver 312 may perform spatial processing on the information to recover any spatial streams destined for the UE 302. If multiple spatial streams are destined for the UE 302, they may be combined by the receiver 312 into a single OFDM symbol stream. The receiver 312 then converts the OFDM symbol stream from the time domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, as well as the reference signal, are recovered and demodulated by determining the most likely signal constellation point transmitted by the base station 304. These soft decisions may be based on channel estimates calculated by a channel estimator. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally transmitted on the physical channel by the base station 304. The data and control signals are then provided to one or more processors 332 that implement Layer 3 (L3) and Layer 2 (L2) functions.

[0071]

[0086] In the uplink, one or more processors 332 provide demultiplexing between transport and logical channels, packet reassembly, decryption, header recovery, and control signal processing to recover IP packets from the core network. The one or more processors 332 are also responsible for error detection.

[0072]

[0087] Similar to the functions described in connection with downlink transmissions by the base station 304, the one or more processors 332 provide RRC layer functions related to system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functions related to header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functions related to transfer of upper layer PDUs, error correction via ARQ, concatenation, segmentation, and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions related to 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 via hybrid automatic repeat request (HARQ), priority handling, and logical channel prioritization.

[0073]

[0088] Channel estimates derived by the channel estimator from a reference signal or feedback transmitted by the base station 304 may be used by the transmitter 314 to select an appropriate coding and modulation scheme and to facilitate spatial processing. The spatial streams generated by the transmitter 314 may be provided to different antennas 316. The transmitter 314 may modulate an RF carrier with each spatial stream for transmission.

[0074]

[0089] Uplink transmissions are processed at the base station 304 in a manner similar to that described with respect to the receiver function at the UE 302. The receiver 352 receives signals through its respective antenna 356. The receiver 352 recovers information modulated onto an RF carrier and provides the information to one or more processors 384.

[0075]

[0090] In the uplink, the one or more processors 384 provide demultiplexing between transport and logical channels, packet reassembly, decryption, header recovery, and control signal processing to recover IP packets from the UE 302. The IP packets from the one or more processors 384 may be provided to a core network. The one or more processors 384 are also responsible for error detection.

[0076]

[0091] For convenience, the UE 302, base station 304, and / or network entity 306 are illustrated in Figures 3A, 3B, and 3C as including various components that may be configured according to various examples described herein. However, it will be understood that the illustrated components may have different functions in different designs. In particular, various components in Figures 3A-3C are optional in alternative configurations, and various aspects include configurations that may vary due to design choice, cost, device use, or other considerations. For example, in the case of Figure 3A, a particular implementation of the UE 302 may omit the WWAN transceiver 310 (e.g., a wearable device or tablet computer or PC or laptop may have Wi-Fi and / or Bluetooth capabilities without cellular capabilities), or may omit the short-range wireless transceiver 320 (e.g., cellular only, etc.), or may omit the SPS receiver 330, or may omit the sensor 344, and so on. 3B, a particular implementation of base station 304 may omit WWAN transceiver 350 (e.g., a Wi-Fi "hotspot" access point without cellular capability), or may omit short-range wireless transceiver 360 (e.g., cellular only), or may omit SPS receiver 370, etc. For brevity, examples of various alternative configurations are not provided herein, but should be readily apparent to one of ordinary skill in the art.

[0077]

[0092] The various components of the UE 302, base station 304, and network entity 306 may be communicatively coupled to one another via data buses 334, 382, ​​and 392, respectively. In an aspect, the data buses 334, 382, ​​and 392 may form or be part of communication interfaces of the UE 302, base station 304, and network entity 306, respectively. For example, when various logical entities are embodied within the same device (e.g., gNB and location server functionality integrated within the same base station 304), the data buses 334, 382, ​​and 392 may provide communication therebetween.

[0078]

[0093] The components of Figures 3A, 3B, and 3C may be implemented in a variety of ways. In some implementations, the components of Figures 3A, 3B, and 3C may be implemented in one or more circuits, such as, for example, one or more processors and / or one or more ASICs (which may include one or more processors), where each circuit may use and / or incorporate at least one memory component for storing information or executable code used by the circuit to provide its functionality. For example, some or all of the functionality represented by blocks 310-346 may be implemented by the processor and memory components of the UE 302 (e.g., by execution of appropriate code and / or by appropriate configuration of the processor components). Similarly, some or all of the functionality represented by blocks 350-388 may be implemented by the processor and memory components of the base station 304 (e.g., by execution of appropriate code and / or by appropriate configuration of the processor components). Also, some or all of the functionality represented by blocks 390-398 may be implemented by the processor and memory components of the network entity 306 (e.g., by execution of appropriate code and / or by appropriate configuration of the processor components). For simplicity, various operations, actions, and / or functions are described herein as being performed "by the UE," "by the base station," "by the network entity," etc. However, it will be understood that such operations, actions, and / or functions may actually be performed by a particular component or combination of components of the UE 302, base station 304, network entity 306, etc., such as the processors 332, 384, 394, transceivers 310, 320, 350, and 360, memories 340, 386, and 396, AoD components 342, 388, and 398, etc.

[0079]

[0094] In some designs, the network entity 306 may be implemented as a core network component. In other designs, the network entity 306 may be separate from the network operator or operation of the cellular network infrastructure (e.g., the NG RAN 220 and / or the 5GC 210 / 260). For example, the network entity 306 may be a component of a private network that may be configured to communicate with the UE 302 via the base station 304 or independently of the base station 304 (e.g., via a non-cellular communication link such as WiFi).

[0080]

[0095] Various frame structures may be used to support downlink and uplink transmissions between network nodes (e.g., base stations and UEs). Figures 4A-4D are diagrams illustrating example frame structures and channels within the frame structures according to aspects of the present disclosure. Other wireless communication technologies may have different frame structures and / or different channels.

[0081]

[0096] FIG. 4A is a diagram 400 illustrating an example of a downlink frame structure according to an embodiment of the disclosure. LTE and NR in some instances utilize OFDM on the downlink and single-carrier frequency division multiplexing (SC-FDM) on the uplink. However, unlike LTE, NR also has the option of using OFDM on the uplink. OFDM and SC-FDM partition the system bandwidth into multiple (K) orthogonal subcarriers, also commonly referred to as tones, bins, etc. Each subcarrier may be modulated with data. Generally, modulation symbols are sent in the frequency domain with OFDM and in the time domain with SC-FDM. The spacing between adjacent subcarriers may be fixed, or the total number of subcarriers (K) may depend on the system bandwidth. For example, the subcarrier spacing may be 15 kilohertz (kHz), and the minimum resource allocation (resource block) may be 12 subcarriers (i.e., 180 kHz). Thus, the nominal FFT size may be equal to 128, 256, 512, 1024, or 2048 for a system bandwidth of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), respectively. The system bandwidth may also be partitioned into subbands. For example, a subband may cover 1.08 MHz (i.e., 6 resource blocks), and there may be 1, 2, 4, 8, or 16 subbands for a system bandwidth of 1.25, 2.5, 5, 10, or 20 MHz, respectively.

[0082]

[0097] LTE supports a single numerology (subcarrier spacing (SCS), symbol length, etc.). In contrast, NR may support multiple numerologies (μ), e.g., subcarrier spacings of 15 kHz (μ=0), 30 kHz (μ=1), 60 kHz (μ=2), 120 kHz (μ=3), and 240 kHz (μ=4) or more may be available. At each subcarrier spacing, there are 14 symbols per slot. For a 15 kHz SCS (μ=0), there is one slot per subframe, i.e., 10 slots per frame, the slot duration is 1 millisecond (ms), the symbol duration is 66.7 microseconds (μs), and the maximum nominal system bandwidth (in MHz) with an FFT size of 4K is 50. For a 30 kHz SCS (μ=1), there are two slots per subframe, i.e., 20 slots per frame, the slot duration is 0.5 ms, the symbol duration is 33.3 μs, and the maximum nominal system bandwidth (in MHz) for a 4K FFT size is 100. For a 60 kHz SCS (μ=2), there are four slots per subframe, i.e., 40 slots per frame, the slot duration is 0.25 ms, the symbol duration is 16.7 μs, and the maximum nominal system bandwidth (in MHz) for a 4K FFT size is 200. For a 120 kHz SCS (μ=3), there are eight slots per subframe, i.e., 80 slots per frame, the slot duration is 0.125 ms, the symbol duration is 8.33 μs, and the maximum nominal system bandwidth (in MHz) for a 4K FFT size is 400. For a 240 kHz SCS (μ=4), there are 16 slots per subframe, i.e., 160 slots per frame, the slot duration is 0.0625 ms, the symbol duration is 4.17 μs, and the maximum nominal system bandwidth (in MHz) with an FFT size of 4K is 800.

[0083]

[0098] In the example of Figures 4A-4D, a numerology of 15 kHz is used. Thus, in the time domain, a 10 ms frame is divided into 10 equally sized subframes of 1 ms each, with each subframe containing one time slot. In Figures 4A-4D, time is represented horizontally (on the X-axis), with time increasing from left to right, and frequency is represented vertically (on the Y-axis), with frequency increasing (or decreasing) from bottom to top.

[0084]

[0099] A resource grid may be used to represent a time slot, with each time slot including one or more time-parallel resource blocks (RBs) (also called physical RBs (PRBs)) in the frequency domain. The resource grid is further divided into multiple resource elements (REs). An RE may correspond to one symbol length in the time domain and one subcarrier in the frequency domain. In the numerology of Figures 4A-4D, for a normal cyclic prefix, an RB may include 12 consecutive subcarriers in the frequency domain and 7 consecutive symbols in the time domain to obtain a total of 84 REs. For an extended cyclic prefix, an RB may include 12 consecutive subcarriers in the frequency domain and 6 consecutive symbols in the time domain to obtain a total of 72 REs. The number of bits carried by each RE depends on the modulation scheme.

[0085]

[0100] Some of the REs carry downlink reference (pilot) signals (DL-RS). DL-RS may include positioning reference signals (PRS), tracking reference signals (TRS), phase tracking reference signals (PTRS), cell-specific reference signals (CRS), channel state information reference signals (CSI-RS), demodulation reference signals (DMRS), primary synchronization signals (PSS), secondary synchronization signals (SSS), synchronization signal blocks (SSB), etc. Figure 4A illustrates example locations of REs carrying PRS (labeled "R").

[0086]

[0101] A collection of resource elements (REs) used for transmission of a PRS is called a "PRS resource." A collection of resource elements can span multiple PRBs in the frequency domain and "N" consecutive symbols (e.g., one or more) within a slot in the time domain. Within a given OFDM symbol in the time domain, a PRS resource occupies consecutive PRBs in the frequency domain.

[0087]

[0102] The transmission of PRS resources within a given PRB has a particular comb size (also called "comb density"). The comb size "N" represents the subcarrier spacing (or frequency / tone spacing) within each symbol of the PRS resource configuration. Specifically, for comb size "N", a PRS is transmitted in every Nth subcarrier of a symbol of the PRB. For example, for Com 4, for each symbol of the PRS resource configuration, an RE corresponding to every fourth subcarrier (such as subcarriers 0, 4, 8) is used to transmit the PRS of the PRS resource. Currently, the following comb sizes are supported for DL-PRS: Com 2, Com 4, Com 6, and Com 12. FIG. 4A shows an example PRS resource configuration for Com 6 (spanning six symbols). That is, the location of the shaded RE (labeled "R") indicates the Com 6 PRS resource configuration.

[0088]

[0103] Currently, DL-PRS resources may span 2, 4, 6, or 12 consecutive symbols in a slot with a staggered pattern across the frequency domain. DL-PRS resources may be configured in any higher layer configured downlink or flexible (FL) symbol of a slot. There may be a constant energy per resource element (EPRE) for all REs of a given DL-PRS resource. Below are the symbol-to-symbol frequency offsets for comb sizes 2, 4, 6, and 12 spanning 2, 4, 6, and 12 symbols. 2symbolcom2:{0,1}; 4symbolcom2:{0,1,0,1}; 6symbolcom2:{0,1,0,1,0,1}; 12symbolcom2:{0,1,0,1,0,1,0,1,0,1,0,1}; 4symbolcom4:{0,2,1,3}; 12symbolcom4:{0,2,1,3,0,2,1,3,0,2,1,3}; 6symbolcom6:{0,3,1,4,2,5}; 12symbolcom6:{0,3,1,4,2,5,0,3,1,4,2,5}; and 12symbolcom12:{0,6,3,9,1,7,4,10,2,8,5,11}.

[0089]

[0104] A "PRS resource set" is a set of PRS resources used for transmission of a PRS signal, where each PRS resource has a PRS resource ID. In addition, the PRS resources in a PRS resource set are associated with the same TRP. A PRS resource set is identified by a PRS resource set ID and is associated with a particular TRP (identified by a TRP ID). In addition, the PRS resources in a PRS resource set have the same periodicity across slots, a common muting pattern configuration, and the same repetition factor (e.g., "PRS-ResourceRepetitionFactor"). The periodicity is the time from the first repetition of the first PRS resource of the first PRS instance to the same first repetition of the same first PRS resource of the next PRS instance. The periodicity may be μ=0, 1, 2, 3 and may have a length selected from 2^μ*{4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 160, 320, 640, 1280, 2560, 5120, 10240} slots. The repetition factor may have a length selected from {1, 2, 4, 6, 8, 16, 32} slots.

[0090]

[0105] A PRS resource ID in a PRS resource set is associated with a single beam (or beam ID) transmitted from a single TRP (where a TRP may transmit one or multiple beams). That is, each PRS resource in a PRS resource set may be transmitted on a different beam, and thus may also be referred to as a "PRS resource" or simply a "resource", also sometimes referred to as a "beam". Note that this does not have any implication as to whether the TRP and beam on which the PRS is transmitted are known to the UE.

[0091]

[0106] A "PRS instance" or "PRS occasion" is one instance of a periodically repeating time window (e.g., a group of one or more contiguous slots) during which a PRS is expected to be transmitted. A PRS occasion may also be referred to as a "PRS positioning occasion", "PRS positioning instance", "positioning occasion", "positioning instance", "positioning repetition", or simply an "occasion", "instance", or "repetition".

[0092]

[0107] A "positioning frequency layer" (also simply called "frequency layer") is a collection of one or more PRS resource sets across one or more TRPs with the same values ​​for some parameters. In particular, the collection of PRS resource sets has the same subcarrier spacing and cyclic prefix (CP) type (meaning that all numerologies supported for PDSCH are also supported for PRS), the same Point A, the same value of downlink PRS bandwidth, the same starting PRB (and center frequency), and the same comb size. The Point A parameter takes the value of the parameter "ARFCN-ValueNR" (where "ARFCN" stands for "absolute radio-frequency channel number"), which is an identifier / code that specifies a pair of physical radio channels used for transmission and reception. The downlink PRS bandwidth may have a granularity of 4 PRB, with a minimum of 24 PRB and a maximum of 272 PRB. Currently, up to four frequency layers are defined, and up to two PRS resource sets per TRP per frequency layer can be configured.

[0093]

[0108] The concept of frequency layer is somewhat like that of component carrier and bandwidth portion (BWP), but differs in that component carrier and BWP are used by one base station (or macrocell base station and small cell base station) to transmit data channels, whereas frequency layer is used by several (usually three or more) base stations to transmit PRS. A UE may indicate the number of frequency layers that it can support when the UE transmits its positioning capabilities to the network, such as during an LTE Positioning Protocol (LPP) session. For example, the UE may indicate whether it can support one positioning frequency layer or four positioning frequency layers.

[0094]

[0109] FIG. 4B is a diagram 430 illustrating an example of channels in a downlink frame structure according to an embodiment of the disclosure. In NR, the channel bandwidth or system bandwidth is divided into multiple BWPs. A BWP is a contiguous set of PRBs selected from a contiguous subset of common RBs for a given numerology on a given carrier. In general, up to 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 with up to four BWPs on the uplink. Only one BWP (uplink or downlink) may be active at a given time, meaning that a UE can only receive or transmit via one BWP at a time. On the downlink, the bandwidth of each BWP should be equal to or greater than the bandwidth of an SSB, but each BWP may or may not include an SSB.

[0095]

[0110] Referring to FIG. 4B, a primary synchronization signal (PSS) is used by the UE to determine subframe / symbol timing and physical layer identity. A secondary synchronization signal (SSS) is used by the UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine the PCI. Based on the PCI, the UE can determine the location of the DL-RS mentioned above. A physical broadcast channel (PBCH) carrying the MIB may be logically grouped with the PSS and SSS to form an SSB (also called SS / PBCH). The MIB provides the number of RBs in the downlink system bandwidth and the system frame number (SFN). A physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted over the PBCH, such as system information blocks (SIBs), and paging messages.

[0096]

[0111] The Physical Downlink Control Channel (PDCCH) carries downlink control information (DCI) in one or more control channel elements (CCEs), where each CCE contains one or more RE group (REG) bundles (which may span multiple symbols in the time domain), where each REG bundle contains one or more REGs, where each REG corresponds to 12 resource elements (one resource block) in the frequency domain and one OFDM symbol in the time domain. The set of physical resources used to carry the PDCCH / DCI is called a control resource set (CORESET) in NR. In NR, the PDCCH is confined to a single CORESET and transmitted with its own DMRS. This allows UE-specific beamforming for the PDCCH.

[0097]

[0112] In the example of Figure 4B, there is one CORESET per BWP, and the CORESET spans three symbols in the time domain (although it may be only one or two symbols). Unlike the LTE control channel, which occupies the entire system bandwidth, in NR, the PDCCH channel is confined to a specific region (i.e., the CORESET) in the frequency domain. Thus, the frequency components of the PDCCH shown in Figure 4B are shown as smaller than a single BWP in the frequency domain. Note that the shown CORESETs are contiguous in the frequency domain, but need not be. In addition, the CORESET may span less than three symbols in the time domain.

[0098]

[0113] The DCI in the PDCCH carries information about uplink resource allocations (persistent and non-persistent), called uplink grants and downlink grants, respectively, and a description of the downlink data to be transmitted to the UE. More specifically, the DCI indicates resources scheduled for a downlink data channel (e.g., PDSCH) and an uplink data channel (e.g., PUSCH). Multiple (e.g., up to eight) DCIs may be configured in the PDCCH, and these DCIs may have one of multiple formats. For example, there are different DCI formats for uplink scheduling, downlink scheduling, uplink transmit power control (TPC), etc. The PDCCH may be transmitted with 1, 2, 4, 8, or 16 CCEs to accommodate different DCI payload sizes or coding rates.

[0099]

[0114] FIG. 4C is a diagram 450 illustrating an example of an uplink frame structure according to an aspect of the disclosure. As shown in FIG. 4C, some of the REs (labeled "R") carry DMRS for channel estimation at a receiver (e.g., a base station, another UE, etc.). The UE may additionally transmit an SRS, e.g., in the last symbol of a slot. The SRS may have a comb structure, and the UE may transmit the SRS on one of the combs. In the example of FIG. 4C, the SRS shown is comb 2 spanning one symbol. The SRS may be used by the base station to obtain channel state information (CSI) for each UE. The CSI describes how the RF signal propagates from the UE to the base station, and describes the combined effects of scattering, fading, and power attenuation with distance. The system uses the SRS for resource scheduling, link adaptation, massive MIMO, beam management, etc.

[0100]

[0115] Currently, an SRS resource can span 1, 2, 4, 8, or 12 consecutive symbols within a slot with comb size Com 2, Com 4, or Com 8. The following are the frequency offsets from symbol to symbol for the currently supported SRS comb patterns: 1 symbol Com 2: {0}; 2 symbols Com 2: {0,1}; 4 symbols Com 2: {0,1,0,1}; 4 symbols Com 4: {0,2,1,3}; 8 symbols Com 4: {0,2,1,3,0,2,1,3}; 12 symbols Com 4: {0,2,1,3,0,2,1,3,0,2,1,3}; 4 symbols Com 8: {0,4,2,6}; 8 symbols Com 8: {0,4,2,6,1,5,3,7}; and 12 symbols Com 8: {0,4,2,6,1,5,3,7,0,4,2,6}.

[0101]

[0116] A set of resource elements used for transmitting an SRS is called an "SRS resource" and may be identified by the parameter "SRS-ResourceId." A set of resource elements may span multiple PRBs in the frequency domain and N (e.g., one or more) consecutive symbols in a slot in the time domain. Within a given OFDM symbol, an SRS resource occupies consecutive PRBs. An "SRS resource set" is a set of SRS resources used for transmitting an SRS signal and is identified by an SRS resource set ID ("SRS-ResourceSetId").

[0102]

[0117] Generally, a UE transmits an SRS to enable a receiving base station (either a serving base station or a neighboring base station) to measure the channel quality between the UE and the base station. However, an SRS may also be specifically configured as an uplink positioning reference signal for uplink-based positioning procedures such as uplink time difference of arrival (UL-TDOA), round-trip time (RTT), uplink angle-of-arrival (UL-AoA), etc. The term "SRS" as used herein may refer to an SRS configured for channel quality measurement or an SRS configured for positioning purposes. When it is necessary to distinguish between the two types of SRS, the former may be referred to herein as "communication SRS" and / or the latter may be referred to as "positioning SRS".

[0103]

[0118] Several extensions beyond the previous definition of SRS have been proposed for positioning SRS (also called "UL-PRS"), such as new staggered patterns in SRS resources (except single symbol / comb2), new comb types for SRS, new sequences for SRS, more SRS resource sets per component carrier, and more SRS resources per component carrier. In addition, the parameters "SpatialRelationInfo" and "PathLossReference" will be configured based on downlink reference signals or SSBs from neighboring TRPs. Still further, 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 may only be transmitted within the active BWP. Furthermore, there may be no frequency hopping, no repetition factor, there may be a single antenna port, and there may be new lengths for SRS (e.g., 8 and 12 symbols). Also, there may be open loop power control rather than closed loop power control, and Com8 (i.e., SRS transmitted on every 8th subcarrier in the same symbol) may be used. Finally, the UE may transmit from multiple SRS resources over the same transmit beam for UL-AoA. All of these are features added to the current SRS framework, configured (and potentially triggered or activated via MAC Control Element (CE) or DCI) through RRC higher layer signaling.

[0104]

[0119] FIG. 4D is a diagram 480 illustrating an example of channels in an uplink frame structure according to an aspect of the disclosure. A random access channel (RACH), also referred to as a physical random access channel (PRACH), may be in one or more slots in a frame based on a PRACH configuration. The PRACH may include six consecutive RB pairs in a slot. The PRACH allows a UE to perform initial system access and achieve uplink synchronization. A physical uplink control channel (PUCCH) may be placed on the edge of the uplink system bandwidth. The PUCCH carries uplink control information (UCI), such as scheduling requests, CSI reports, channel quality indicators (CQI), precoding matrix indicators (PMI), rank indicators (RI), and HARQ ACK / NACK feedback. A physical uplink shared channel (PUSCH) carries data and may additionally be used to carry buffer status reports (BSR), power headroom reports (PHR), and / or UCI.

[0105]

[0120] It should be noted that the terms "positioning reference signal" and "PRS" generally refer to specific reference signals used for positioning in NR and LTE systems. However, the terms "positioning reference signal" and "PRS" as used herein may also refer to any type of reference signal that can be used for positioning, such as, but not limited to, PRS as defined in LTE and NR, TRS, PTRS, CRS, CSI-RS, DMRS, PSS, SSS, SSB, SRS, UL-PRS, etc. Furthermore, the terms "positioning reference signal" and "PRS" may refer to downlink or uplink positioning reference signals, unless otherwise suggested by the context. If necessary to further distinguish between types of PRS, downlink positioning reference signals may be referred to as "DL-PRS" and uplink positioning reference signals (e.g., SRS for positioning, PTRS) may be referred to as "UL-PRS". In addition, for signals that may be transmitted in both uplink and downlink (e.g., DMRS, PTRS), "UL" or "DL" may be prepended to the signal to distinguish the direction. For example, "UL-DMRS" can be distinguished from "DL-DMRS."

[0106]

[0121] 5 is a diagram 500 illustrating a base station (BS) 502 (which may correspond to any of the base stations described herein) communicating with a UE 504 (which may correspond to any of the UEs described herein). With reference to FIG. 5, the base station 502 may transmit beamformed signals to the UE 504 on one or more transmit beams 502a, 502b, 502c, 502d, 502e, 502f, 502g, each having a beam identifier that may be used by the UE 504 to identify the respective beam. If the base station 502 is beamforming toward the UE 504 with a single array of antennas (e.g., a single TRP / cell), the base station 502 may perform "beam sweeping" by transmitting a first beam 502a, then a beam 502b, and so on, until it finally transmits a beam 502g. Alternatively, the base station 502 may transmit beams 502a-502g in several patterns, such as beam 502a, then beam 502g, then beam 502b, then beam 502f. If the base station 502 is beamforming toward the UE 504 using multiple arrays of antennas (e.g., multiple TRPs / cells), each antenna array may perform beam sweeping of a subset of the beams 502a-502g. Alternatively, each of the beams 502a-502g may correspond to a single antenna or antenna array.

[0107]

[0122] FIG. 5 further illustrates paths 512c, 512d, 512e, 512f, and 512g taken by beamformed signals transmitted on beams 502c, 502d, 502e, 502f, and 502g, respectively. Each path 512c, 512d, 512e, 512f, 512g may correspond to a single "multipath" or may consist of multiple "multipaths" (clusters) due to the propagation characteristics of radio frequency (RF) signals through the environment. Although only paths for beams 502c-502g are illustrated, this is for simplicity's sake, and it should be noted that signals transmitted in each of beams 502a-502g follow several paths. In the illustrated example, paths 512c, 512d, 512e, and 512f are straight lines, and path 512g reflects off an obstacle 520 (e.g., a building, a vehicle, a terrain feature, etc.).

[0108]

[0123] The UE 504 may receive beamformed signals from the base station 502 in one or more receive beams 504a, 504b, 504c, 504d. Note that for simplicity, the beams shown in FIG. 5 represent either transmit or receive beams, depending on which of the base station 502 and the UE 504 is transmitting and which is receiving. Thus, the UE 504 may also transmit beamformed signals to the base station 502 in one or more of the beams 504a-504d, and the base station 502 may receive beamformed signals from the UE 504 in one or more of the beams 502a-502g.

[0109]

[0124] In one aspect, the base station 502 and the UE 504 may perform beam training to align the transmit and receive beams of the base station 502 and the UE 504. For example, depending on environmental conditions and other factors, the base station 502 and the UE 504 may determine that the best transmit and receive beams are 502d and 504b, respectively, or are beams 502e and 504c, respectively. The direction of the best transmit beam for the base station 502 may or may not be the same as the direction of the best receive beam, and similarly, the direction of the best receive beam for the UE 504 may or may not be the same as the direction of the best transmit beam. However, it should be noted that the transmit and receive beams do not need to be aligned to perform a downlink angle of departure (DL-AoD) or uplink angle of arrival (UL-AoA) positioning procedure.

[0110]

[0125] To perform the DL-AoD positioning procedure, the base station 502 may transmit reference signals (e.g., PRS, CRS, TRS, CSI-RS, PSS, SSS, etc.) to the UE 504 in one or more of the beams 502a-502g, each beam having a different transmit angle. The different transmit angles of the beams result in different received signal strengths (e.g., RSRP, RSRQ, SINR, etc.) at the UE 504. In particular, the received signal strength is smaller in the transmit beams 502a-502g that are farther from a line-of-sight (LOS) path 510 between the base station 502 and the UE 504 than in the transmit beams 502a-502g that are closer to the LOS path 510.

[0111]

[0126] 5, if the base station 502 transmits reference signals to the UE 504 on beams 502c, 502d, 502e, 502f, and 502g, the transmit beam 502e is best aligned with the LOS path 510, but the transmit beams 502c, 502d, 502f, and 502g are not. Thus, the beam 502e may have a greater received signal strength at the UE 504 than the beams 502c, 502d, 502f, and 502g. Note that the reference signals transmitted on some beams (e.g., beams 502c and / or 502f) may not reach the UE 504, or the energy reaching the UE 504 from these beams may be too low such that the energy may not be detectable or may at least be ignored.

[0112]

[0127] The UE 504 may report the received signal strength of each measured transmit beam 502c-502g, and optionally the associated measurement quality, or the identity of the transmit beam with the highest received signal strength (beam 502e in the example of FIG. 5) to the base station 502. Alternatively or additionally, if the UE 504 is also involved in a round-trip-time (RTT) or time-difference-of-arrival (TDOA) positioning session with at least one or more base stations 502, respectively, the UE 504 may report reception-to-transmission (Rx-Tx) or reference signal time difference (RSTD) measurements (and optionally the associated measurement quality) to the serving base station 502 or other positioning entity, respectively. In either case, a positioning entity (e.g., base station 502, location server, third party client, UE 504, etc.) can estimate the angle from base station 502 to UE 504 as the AoD of the transmit beam with the greatest received signal strength at UE 504, here transmit beam 502e.

[0113]

[0128] In one aspect of DL-AoD based positioning, where there is only one base station 502 involved, the base station 502 and the UE 504 can perform a round trip time (RTT) procedure to determine the distance between the base station 502 and the UE 504. Thus, the positioning entity can determine both the direction to the UE 504 (using DL-AoD positioning) and the distance to the UE 504 (using RTT positioning) to estimate the location of the UE 504. It should be noted that the AoD of the transmit beam with the greatest received signal strength is not necessarily along the LOS path 510 as shown in FIG. 5. However, for DL-AoD based positioning purposes, it is assumed to be the case.

[0114]

[0129] In another aspect of DL-AoD based positioning, where there are multiple base stations 502 involved, each base station 502 can report the determined AoD from the base station 502 to the UE 504 to the positioning entity. The positioning entity receives such multiple AoDs from the multiple base stations 502 involved (or other geographically separated transmission points) for the UE 504. With this information and knowledge of the geographical locations of the base stations 502, the positioning entity can estimate the location of the UE 504 as the intersection of the received AoDs. For a two-dimensional (2D) position solution, there should be at least two base stations 502 involved, but as will be appreciated, the more base stations 502 involved in the positioning procedure, the more accurate the estimated UE 504 location will be. In the case of UE-assisted based positioning, the serving base station reports RSRP measurements to the positioning entity (e.g., a location server). The AoD is not determined or reported by each base station.

[0115]

[0130] To perform the UL-AoA positioning procedure, the UE 504 transmits uplink reference signals (e.g., UL-PRS, SRS, DMRS, etc.) in one or more of the uplink transmit beams 504a-504d to the base station 502. The base station 502 receives the uplink reference signals in one or more of the uplink receive beams 502a-502g. The base station 502 determines the angle of the best receive beam 502a-502g used to receive the one or more reference signals from the UE 504 as the AoA from the UE 504 to the base station 502. Specifically, each of the receive beams 502a-502g results in a different received signal strength (e.g., RSRP, RSRQ, SINR, etc.) of the one or more reference signals at the base station 502. Furthermore, the channel impulse response of the one or more reference signals is smaller in receive beams 502a-502g that are farther from the actual LOS path between the base station 502 and the UE 504 than in receive beams 502a-502g that are closer to the LOS path. Similarly, the received signal strength is smaller in receive beams 502a-502g that are farther from the LOS path than in receive beams 502a-502g that are closer to the LOS path. Thus, the base station 502 identifies the receive beam 502a-502g that results in the greatest received signal strength, and optionally the strongest channel impulse response, and estimates the angle from itself to the UE 504 as the AoA of that receive beam 502a-502g. Note that similar to DL-AoD based positioning, the AoA of the receive beam 502a-502g that results in the greatest received signal strength (and strongest channel impulse response, if measured) is not necessarily along the LOS path 510. However, for UL-AoA based positioning purposes, in FR2, it may be assumed that this is the case. For FR1, AoA estimation may be performed using digital beam scanning. For example, the UE 504 may estimate the AoA as the AoA with the fastest path whose power is greater than some threshold.

[0116]

[0131] It should be noted that although the UE 504 is shown as being capable of beamforming, this is not required for DL-AoD and UL-AoA positioning procedures. Rather, the UE 504 may receive and transmit with an omni-directional antenna.

[0117]

[0132] If the UE 504 is estimating its location (i.e., the UE is a positioning entity), it needs to obtain the geographic location of the base station 502. The UE 504 may obtain the location, for example, from the base station 502 itself or from a location server (e.g., location server 230, LMF 270, SLP 272). With knowledge of the distance to the base station 502 (based on the RTT or timing advance), the angle between the base station 502 and the UE 504 (based on the UL-AoA of the best received beam 502a-502g), and the known geographic location of the base station 502, the UE 504 can estimate its location.

[0118]

[0133] Alternatively, if a positioning entity, such as the base station 502 or a location server, is estimating the location of the UE 504, the base station 502 reports the maximum received signal strength (and optionally the strongest channel impulse response) of the reference signal received from the UE 504, or the AoA of the receive beam 502a-502g that results in all received signal strengths and channel impulse responses for all receive beams 502a-502g (allowing the positioning entity to determine the best receive beam 502a-502g). The base station 502 may additionally report the Rx-Tx time difference to the UE 504. The positioning entity can then estimate the location of the UE 504 based on the distance of the UE 504 to the base station 502, the AoA of the identified receive beams 502a-502g, and the known geographic location of the base station 502.

[0119]

[0134] FIG. 6 illustrates a conventional method 600 of performing DL-AoD measurements using RSRP measurements. In FIG. 6, a TRP 602 transmits a set of PRS signals, each at a different azimuth angle. The radiation pattern of each beam is graphically represented by numbered ellipses, with the ellipse numbered 1 representing PRS1, the ellipse numbered 2 representing PRS2, and so on. A UE 604 having a line-of-sight (LOS) path 606 to the TRP 602 performs RSRP measurements for each of the PRS signals and reports those measurements to the TRP 602, which can then forward those measurements to a positioning entity, such as a Location Management Function (LMF) 608. The perceived RSRP of each PRS from the perspective of the UE 604 will depend on the relative angle of the PRS beam with respect to the angle of the LOS path 606, labeled φ1 in FIG. 6. This is represented diagrammatically in Figure 6 as the intersection of the LOS path 606 and the radiation pattern with the beam, with the distance of the intersection from the TRP corresponding to the perceived power of the beam. In the example shown in Figure 6, the angle of the LOS path 606 is closest to the transmit angle of PRS3, so the RSRP of PRS3 measured by the UE 604 is relatively large compared to the RSRP of PRS2 which is larger than the RSRP of PRS4 which is larger than the RSRP of PRS1. The UE 604 reports these RSRP measurements to the TRP 602.

[0120]

[0135] As can be seen in Figure 6, the set of RSRP measurements, i.e., the measured RSRPs of the PRS beams transmitted by the TRP 602 and measured by the UE, vary depending on the azimuth angle φ of the UE. For example, for a UE at azimuth angle φ2 in Figure 6, the RSRP value of PRS4 is the highest, followed by the RSRP values ​​of PRS3, PRS5, and PRS2. The expected RSRP values ​​of each PRS as a function of azimuth angle can be modeled as a set of expected power curves, as shown in Figure 7.

[0121]

[0136] FIG. 7 is a plot of expected RSRP values ​​as a function of azimuth angle, normalized to remove the effect of distance. In the exemplary plot shown in FIG. 7, plots (a), (b), and (c) respectively show expected RSRP values ​​of PRS2, PRS3, and PRS4 as a function of azimuth angle, and plot (d) is a combination of plots (a)-(c). Thus, at each azimuth angle, there is a known ratio of values ​​of PRS2, PRS3, and PRS4. The same concept applies to PRS beams not shown in FIG. 6. TRP 602 transmits the PRS resources measured by UE 604. UE 604 then reports up to eight RSRPs to TRP 602, one for each PRS resource.

[0122]

[0137] In conventional UE-assisted positioning, the TRP 602 reports the measured RSRP value to the LMF 608, for example, via the LPP protocol. The LMF 608 estimates the AoD, i.e., the LMF 608 determines the azimuth of the UE 604 by comparing the RSRP measurement with the expected RSRP value of each PRS, and can use the AoD to calculate the position of the UE 604. In conventional UE-based positioning, the UE 604 estimates the AoD and calculates its own position using assistance data including the geographical positions of the TRP 602 and other TRPs, and PRS beam information (e.g., beam azimuth and elevation angles). In either case, the expected RSRP value needs to be modeled. In one aspect, this is done by the following method: For each potential φk∈[φ1,...,φM] where the UE may be located, calculate the expected Rx power P(i,k) for each beam l∈[1,...Nbeams,] being transmitted. Next, derive a normalized vector P(k,) for each k ∈ [1,...M].

[0123]

number

[0124] This results in a set of normalized expected RSRP values ​​for each PRS beam, i.e., a set of relative RSRP values ​​for the PRS beam at a particular azimuth angle, with as many of these sets as the azimuth angle being considered. For UE-assisted AoD positioning, the LMF 608 calculates the normalized RSRP received vector as

[0125]

number

[0126] and

[0127]

number

[0128] Close to

[0129]

number

[0130] bring about

[0131]

number

[0132] For UE-based AoD positioning, the UE 604 is provided with a set of relative RSRP values ​​for the PRS beams at each of a set of azimuth angles being modeled.

[0133]

[0138] Figure 8 illustrates a system 800 for conventional multi-round trip time (multi-RTT) positioning. The UE's position can be determined by trilateration or multilateration using the known positions of gNB1, gNB2, and gNB3, and the round trip times (RTTs) from each gNB, e.g., RTT1, RTT2, and RTT3 in Figure 8. This method can achieve position accuracy within 3 m for well-synchronized networks, but requires multiple gNBs.

[0134]

[0139] FIG. 9 illustrates a system 900 for TDoA positioning using a single gNB. In FIG. 9, a serving gNB (SgNB) or other type of serving base station controls a pair of reconfigurable intelligent surfaces (RIS), e.g., RIS1 and RIS2, that ultimately provide transmissions toward the UE. The SgNB transmits a set of positioning reference signals, e.g., PRS1, PRS2, and PRS3, to a target UE. PRS1 is directed to RIS1, which transmits a reflected signal PRS1' toward the UE. PRS2 is directed to RIS2, which transmits a reflected signal PRS2' toward the UE. PRS3 is directed directly to the UE. In the example illustrated in FIG. 9, PRS3 first arrives at the UE at time ToA(SgNB). PRS1 arrives at RIS1 at time Tprop(SgNB→PRS1), and PRS1' arrives at the UE at time ToA(RIS1). PRS2 arrives at RIS2 at time Tprop(SgNB→PRS2) and PRS2' arrives at the UE at time ToA(RIS2). The UE measures the time of arrival (ToA) of each of PRS1', PRS2', and PRS3.

[0135]

[0140] In UE-assisted positioning, the UE simply reports the RSTD of PRS1', PRS2', and PRS3. From that information, and the known positions of SgNB, RIS1, and RIS2, a location server or other node can determine the distance of the UE to SgNB, RIS1, and RIS2. In this way, the position of the UE can be determined using a multilateration method within a single cell, which is useful for low tier UEs. Since the UE does not need to transmit SRS, it can perform positioning based only on the received DL-PRS, which is a low-power solution compared to traditional RTT.

[0136]

[0141] In UE-based positioning, the UE needs to know the transmission times of PRS1', PRS2', and PRS3. The assistance data provides the UE with the location of the base station and the RIS, and the UE knows the transmission times of PRS1, PRS2, and PRS3 from the PRS configuration. If the transmission times of PRS1' and PRS2' are not directly known, the UE can derive this information from knowing the transmission time of PRS1 and the hardware delay in RIS1 between receiving PRS1 and transmitting PRS1', which the UE can obtain from the assistance data from the base station. Similarly, the UE can derive the transmission time of PRS2' based on the transmission time of PRS2 and the hardware delay in RIS2 between receiving PRS2 and transmitting PRS2'.

[0137]

[0142] FIG. 10 illustrates a system 1000 for multi-RTT positioning using a UL-SRS signal and multiple RISs, e.g., RIS1, RIS2, and RIS3. The top of FIG. 10 illustrates the geographic locations of the entities involved in an exemplary scenario, and the bottom of FIG. 10 illustrates an exemplary timing of signal transmission and reflection in this exemplary scenario. In the example illustrated in the bottom of FIG. 10, at time T1, the UE transmits a UL-SRS signal 1002 to the RIS, and the RIS receives the UL-SRS signal at time T2. At time T3, the RIS reflects a UL-SRS signal 1004 to the UE. The UE is guided (e.g., by network assistance data) to receive the reflected UL-SRS signal 1004 at time T4. The RX beam for the UE to receive the reflected UL-SRS signal 1004 may be the same as the TX beam used by the UE to transmit the UL-SRS signal 1002.

[0138]

[0143] In UE assisted positioning, the UE can report the time delay (T4-T1) to a location server or other network node. From that information, along with the hardware delay (T3-T2) at the RIS between receiving the UL-SRS signal 1002 and transmitting the reflected UL-SS signal 1004, the location server can determine the distance from the UE to the RIS.

[0139]

[0144] In UE-based positioning, when the UE receives and verifies the reflected UL-SRS signal 1004, the UE calculates the RTT for the RIS by T RTT =(T4-T1)-(T3-T2)≒2 * Tprop (UE<->RIS) where the UE determines a value of (T4-T1) and receives a value of (T3-T2), e.g., as assistance data provided by a base station controlling that RIS. The UE may then estimate its distance from the RIS based on the RTT to the RIS. After the UE determines the RTT of a sufficient number of reflected UL-SRS signals, it can derive its location based on trilateration or multilateration from multiple RISs. The UE does not need to measure DL-PRS signals and can avoid transmitting SRS at high power towards the gNB by transmitting at lower power towards the closer RIS, both reducing power consumption.

[0140]

[0145] However, this technique still requires that the UE be able to transmit UL-SRS to multiple RISs and receive reflections of those UL-SRSs from multiple RISs. This can be problematic when low tier (e.g., low capacity) UEs, such as "NR-lite" UEs, may not be able to transmit to or receive from a distant RIS. This difficulty can be mitigated somewhat if the RIS is close to the UE, but then the UE must repeat the process for multiple RISs, which consumes more power. A further drawback of this technique is that it requires at least two RISs, which is not the case in many cases.

[0141]

[0146] To address these technical challenges, techniques are presented for UE-based positioning using a single RIS. The methods and systems disclosed herein determine the location of the UE relative to the RIS by using range and AoD techniques, rather than using trilateration / multilateration techniques that require distance measurements from multiple reference points.

[0142]

[0147] FIG. 11 is a flowchart of an example process 1100 associated with RIS beam sweeping of an SRS for AoD-based positioning according to an aspect of the disclosure. In some implementations, one or more process blocks of FIG. 11 may be performed by a UE (e.g., UE 103, UE 1404, etc.). In some implementations, one or more process blocks of FIG. 11 may be performed by another device or a group of devices that are separate from or include the user equipment (UE). Additionally or alternatively, one or more process blocks of FIG. 11 may be performed by one or more components of the UE 302, such as the processor 332, memory 340, WWAN transceiver 310, short-range wireless transceiver 320, SPS receiver 330, user interface 346, and / or AoD component 342, any or all of which may be considered as a means for performing the operations.

[0143]

[0148] As shown in FIG. 11, the process 1100 may include obtaining configuration information identifying resources for sounding reference signal (SRS) positioning (block 1110). Means for performing the operations of block 1110 may include the WWAN transceiver 310 of the UE 302. For example, the UE 302 may receive the configuration information via the receiver 312. In some aspects, obtaining the configuration information includes receiving the configuration information via radio resource control (RRC) signaling. In some aspects, obtaining the configuration information includes receiving the configuration information from a network entity. In some aspects, receiving the configuration information from the network entity includes receiving the configuration information from a location server. In some aspects, the configuration information indicates a number of SRS resources, a time to transmit an SRS transmission to a RIS, an expected time to receive a reflection of the SRS transmission from the RIS, an uncertainty in the expected time to receive a reflection of the SRS transmission from the RIS, or a combination thereof.

[0144]

[0149] 11, for a reconfigurable intelligent surface (RIS), process 1100 may include transmitting multiple SRS transmissions at different times according to the configuration information (block 1120). Means for performing the operations of block 1120 may include the WWAN transceiver 310 of the UE 302. For example, the UE 302 may transmit multiple SRS transmissions at different times via the transmitter 314.

[0145]

[0150] As further illustrated in FIG. 11, the process 1100 may include receiving a plurality of SRS transmissions from the RIS, including reflections of the plurality of SRS transmissions to the RIS, where each of the plurality of SRS transmissions from the RIS is transmitted at a different angle of departure (AoD) from the RIS (block 1130). Means for performing the operations of block 1130 may include the WWAN transceiver 310 of the UE 302. For example, the UE 302 may receive the plurality of SRS transmissions via the receiver 312. In some aspects, each of the plurality of SRS transmissions from the RIS is received at a known time or at a known delay after transmitting the corresponding SRS transmission to the RIS according to configuration information. In some aspects, each of the plurality of SRS transmissions from the RIS includes information associating it with a corresponding one of the plurality of SRS transmissions to the RIS. For example, the SRS transmitted by the UE and the reflected SRS received from the RIS may have the same SRS ID, the same beam ID, the same known sequence, etc., or a combination of the above.

[0146]

[0151] 11, the process 1100 may include measuring each of the multiple SRS transmissions from the RIS to generate multiple measurements (block 1140). Means for performing the operations of block 1140 may include the WWAN transceiver 310 of the UE 302. For example, the UE 302 may measure each of the multiple SRS transmissions from the RIS with the receiver 312. In some aspects, the UE 302 measures a set of RSRP values ​​for each SRS transmission from the RIS.

[0147]

[0152] As further shown in FIG. 11, the process 1100 may include performing a positioning operation based on the plurality of measurements (block 1150). Means for performing the operations of block 1150 may include the processor 332 and the WWAN transceiver 310 of the UE 302. For example, in some aspects, performing a positioning operation based on the plurality of measurements includes transmitting the plurality of measurements to a location server, e.g., via the transmitter 314, and then receiving a position estimate from the location server, e.g., via the receiver 312, based on the plurality of measurements. In other aspects, performing a positioning operation based on the plurality of measurements includes determining an AoD of the UE from the RIS based on the plurality of measurements. In some aspects, this includes receiving assistance data via the receiver 312. The assistance data may include information such as a geographical location of the RIS, an orientation of the RIS, characteristics of the reflected SRS beam, or a combination thereof, that is taken into account by the processor 332 while determining the AoD of the UE from the RIS. In some aspects, the characteristics of the reflected SRS beam include an azimuth angle or beam width, an elevation angle or beam width, boresight direction uncertainty, beam width uncertainty, transmission time uncertainty, or a combination thereof. In some aspects, the process 1100 includes estimating a position of the UE based on the AoD and a distance from the UE to the RIS.

[0148]

[0153] Process 1100 may include additional implementations, such as any single implementation or any combination of implementations described below and / or with respect to one or more other processes described elsewhere herein. Although Figure 11 illustrates example blocks of process 1100, in some implementations process 1100 may include additional, fewer, different, or differently configured blocks than those illustrated in Figure 11. Additionally or alternatively, two or more of the blocks of process 1100 may be performed in parallel.

[0149]

[0154] FIG. 12 is a flow chart of an example process 1200 associated with RIS beam sweeping of an SRS for AoD-based positioning according to an aspect of the disclosure. In some implementations, one or more process blocks of FIG. 12 may be performed by a RIS (such as, for example, RIS 1406). In some implementations, one or more process blocks of FIG. 12 may be performed by another device or group of devices separate from or including a reconfigurable intelligent surface (RIS). Additionally or alternatively, one or more process blocks of FIG. 12 may be performed by one or more components of the RIS 304, such as the processor 384, memory 386, WWAN transceiver 350, short-range wireless transceiver 360, SPS receiver 370, network transceiver 380, and / or AoD component 388, any or all of which may be considered as a means for performing the operations.

[0150]

[0155] As shown in FIG. 12, the process 1200 may include obtaining configuration information identifying resources for sounding reference signal (SRS) positioning (block 1210). Means for performing the operations of block 1210 may include the WWAN transceiver 350 and the network transceiver 380 of the device 304. For example, the RIS may receive the configuration information from a location server via the WWAN transceiver 350 or the network transceiver 380. In some aspects, obtaining the configuration information includes receiving the configuration information via radio resource control (RRC) signaling, for example, from a base station controlling the RIS. In some aspects, obtaining the configuration information includes receiving the configuration information from a network entity, which may be a location server, an LMF, or other network node. In some aspects, the configuration information indicates a number of SRS resources, an expected time to receive an SRS transmission from the UE, an uncertainty in the expected time to receive an SRS transmission from the UE, an expected time to transmit a reflection of the SRS transmission from the UE to the UE, an AoD to transmit a reflection of each SRS transmission from the UE, or a combination thereof.

[0151]

[0156] 12, the process 1200 may include receiving multiple SRS transmissions at different times from a user equipment (UE) (block 1220). Means for performing the operations of block 1220 may include the WWAN transceiver 350 of the device 304. For example, the RIS may receive the multiple SRS transmissions via the receiver 352.

[0152]

[0157] As further illustrated in FIG. 12, the process 1200 may include transmitting a plurality of SRS transmissions, the plurality of SRS transmissions including reflections of the plurality of SRS transmissions received from the UE, where each of the plurality of SRS transmissions from the RIS is transmitted at a different angle of departure (AoD) from the RIS according to the configuration information (block 1230). Means for performing the operations of block 1230 may include the WWAN transceiver 350 of the device 306. For example, the RIS may transmit the plurality of reflected SRS transmissions via the transmitter 354. In some aspects, each of the plurality of SRS transmissions including reflections of the plurality of SRS transmissions received from the UE includes information associating each of them with a corresponding SRS transmission of the plurality of SRS transmissions received from the UE. In some aspects, the SRS received from the UE and the reflected SRS transmitted by the RIS may have the same SRS ID, the same beam ID, the same known sequence, or the like, or a combination thereof.

[0153]

[0158] Process 1200 may include additional implementations, such as any single implementation or any combination of implementations described below and / or with respect to one or more other processes described elsewhere herein. Although Figure 12 illustrates example blocks of process 1200, in some implementations process 1200 may include additional, fewer, different, or differently configured blocks than those illustrated in Figure 12. Additionally or alternatively, two or more of the blocks of process 1200 may be performed in parallel.

[0154]

[0159] 13A and 13B are flow charts illustrating a portion of an exemplary process 1300 associated with RIS beam sweeping of an SRS for AoD-based positioning according to an aspect of the disclosure. In some implementations, one or more process blocks in FIG. 13A and 13B may be performed by a location server (e.g., location server 172, LMF 1402, etc.) or a base station (e.g., BS 102, BS 304, etc.). In some implementations, one or more process blocks in FIG. 13A and 13B may be performed by another device or group of devices that are separate from or include a location server (LS). Additionally or alternatively, one or more process blocks in FIG. 13A and 13B may be performed by one or more components of device 306, such as processor 394, memory 396, network transceiver 390, and / or AoD component 398, any or all of which may be considered as a means for performing the operations.

[0155]

[0160] As shown in FIG. 13A, the process 1300 may include transmitting, to a reconfigurable intelligent surface (RIS), first configuration information identifying resources for sounding reference signal (SRS) positioning (block 1310). Means for performing the operations of block 1310 may include the network transceiver 390 of the device 306. As further shown in FIG. 13A, the process 1300 may include transmitting, to a user equipment (UE), second configuration information identifying resources for sounding reference signal (SRS) positioning (block 1320). Means for performing the operations of block 1320 may include the network transceiver 390 of the device 306. In some aspects, the first configuration information and the second configuration information may indicate a number of SRS resources, a time at which the UE transmits an SRS transmission to the RIS, an expected time at which the UE receives a reflection of the SRS transmission from the RIS, an uncertainty of an expected time at which the UE receives a reflection of the SRS transmission from the RIS, an angle of departure (AoD) at which the RIS should transmit a reflection of each SRS transmission from the UE, or a combination thereof.

[0156]

[0161] 13B, process 1300 may optionally include transmitting assistance data to the UE including a geographic location of the RIS, an orientation of the RIS, characteristics of the reflected SS beam, or a combination thereof (block 1330). The characteristics of the reflected SRS beam may include azimuth angle, azimuth beamwidth, elevation angle, elevation beamwidth, boresight direction uncertainty, beamwidth uncertainty, transmission time uncertainty, or a combination thereof.

[0157]

[0162] 13B, process 1300 may optionally include receiving from the UE a plurality of Reference Signal Received Power (RSRP) values ​​corresponding to a plurality of reflected SRS transmissions measured by the UE (block 1340), determining an AoD of the UE from the RIS based on the plurality of RSRP values ​​(block 1350), estimating a position of the UE based at least in part on the AoD (block 1360), and transmitting the position estimate to the UE (block 1370). Means for performing the operations of blocks 1340, 1350, 1360, and 1370 may include a network transceiver 390, a memory 396, a processor 394, and / or an AoD component 398 of the device 306.

[0158]

[0163] Process 1300 may include additional implementations, such as any single implementation or any combination of implementations described below and / or with respect to one or more other processes described elsewhere herein. Although Figures 13A and 13B show example blocks of process 1300, in some implementations process 1300 may include additional, fewer, different, or differently configured blocks than those shown in Figures 13A and 13B. Additionally or alternatively, two or more of the blocks of process 1300 may be performed in parallel.

[0159]

[0164] FIG. 14 illustrates an example of a network 1400 that implements UE-based positioning with a single RIS according to some aspects of the disclosure. In FIG. 14, the network 1400 includes an LMF 1402, a UE 1404, and a RIS 1406, with intervening nodes in the signaling path between the LMF 1402 and the UE 1404 omitted for clarity. The top part of FIG. 14 illustrates example beam patterns, e.g., SRS1′, SRS2′, etc., having different transmit angles A, B, C, etc., respectively, when transmitted by the RIS 1406 according to an SRS configuration received by the RIS 1406. The actual AoD of the UE 1404 is shown in FIG. 14 as a dashed line 1408, and dots located at the intersections of that vector with beam patterns C-F represent the relative RSRP values ​​that the UE 1404 measures for each of those beams, where the closer the dot is to the UE 1404, the higher the relative measured RSRP. In the example shown in FIG. 12, the relative RSRP values, from high to low, are SRS5′, SRS4′, SRS6′, and SRS3′. From this particular pattern, the AoD 1202 of the UE 1404 can be derived using methods similar to those described for FIG. 6 and FIG. 7, for example. The bottom part of FIG. 12 illustrates an example timing assignment of SRS resources to slots, e.g., SRS3 and SRS3′ occur during slot n+2, SRS4 and SRS4′ occur during slot n+3, etc. In this example, the SRS resources are time domain multiplexed, recognizing that the RIS may not have advanced baseband processing capabilities. Furthermore, the RIS may not be able to comb staggered SRS signals into multiple different beams, in which case the RIS can simply reflect any frequency domain multiplexed SRS resources back to the same TX beam for reflection. In FIG. 12, the SRS resources occupy separate slots, but in some aspects the SRS resources may occupy separate symbols in the same slot, separate symbols in different slots, and other configurations. These examples are illustrative and not limiting.

[0160]

[0165] 15 is a signaling and event diagram 1500 for RIS beam sweeping of an SRS for UE-based AoD positioning in accordance with some aspects of the disclosure. In FIG. 15, the process includes an LMF 1402 or other location server, a UE 1404, and a RIS 1406, and takes advantage of the fact that the RIS 1406 can adjust the direction in which it reflects an incoming beam.

[0161]

[0166] In the example shown in FIG. 15, the LMF 1402 transmits an SRS configuration 1502 to the UE 1404 and an SRS setting 1504 to the RIS 1406. The SRS configuration, which may be transmitted by radio resource control (RRC) messaging, identifies SRS resources for positioning. Each SRS configuration may define one or more SRS resource sets, each SRS resource set including one or more time domain multiplexed (TDMed) SRS resources for positioning. In some aspects, each SRS resource for positioning may be defined in terms of slots and / or symbols. For example, there may be one SRS resource for positioning per slot. The SRS resources for positioning may occupy some or all of the symbols in a slot. The slots including SRS resources for positioning may or may not be contiguous with each other, e.g., every other slot, every third slot, various patterns, etc., as needed to fit the UL / DL configuration of TDD. The SRS configuration may define the opportunities for the UE 1404 to transmit a UL-SRS to the RIS 1406, the opportunities for the RIS 1406 to reflect the UL-SRS back to the UE 1404, or a combination thereof. In some aspects, the SRS configuration of the RIS specifies the azimuth and / or elevation angles at which the reflected UL-SRS beam is transmitted. In the example shown in FIG. 15, SRS configuration SRS1′ is transmitted by the RIS 1406 at an AoD of an angle “A”, SRS2′ is transmitted by the RIS 1406 at an AoD of an angle “B”, and so on. Thus, in some aspects, the SRS configuration 1110 may include a mapping of SRS opportunities to reflected AoDs.

[0162]

[0167] In the example shown in FIG. 15, the UE 1404 then begins transmitting a series of UL-SRS signals to the RIS 1406. Each time the RIS 1406 receives a UL-SRS signal from the UE 1404, the RIS 1406 reflects the UL-SRS signal back to the UE 1404 at a different AoD according to the mapping provided by the SRS configuration. For example, the UE 1404 transmits SRS1 1506 to the RIS 1406, which reflects it as SRS1' 1508 at AoD=A, and the UE 1404 measures the RSRP of SRS1' (block 1510). This process is repeated for each SRS until the UE 1404 transmits SRS8 1512 to the RIS 1406, which reflects it as SRS2' 1514 at AoD=H, and the UE 1404 measures the RSRP of SRS8' (block 1516).

[0163]

[0168] In a UE-based implementation, the UE 1404 then uses the measured RSRP values ​​of SRS1' through SRS8' to determine the AoD of the UE 1404 from the RIS 1406 (block 1518), for example, using a technique such as that described with respect to FIG. 6.

[0164]

[0169] In a UE-assisted implementation, the UE 1404 may transmit the measured RSRP value 1520 and, optionally, a distance estimate based on the RTT between the UE 1404 and the RIS 1406 or the RTT value itself to the LMF 1402. The LMF 1402 then uses this information to calculate the AoD and range from the RIS to the UE, which the LMF then uses to estimate the location of the UE 1404 (block 1522). The LMF 1402 can then transmit the estimated location 1524 to the UE 1404.

[0165]

[0170] If the RIS 1406 is performing as a passive mirror and the time difference between receiving the SRS signal and reflecting the SRS signal is negligible, or if the propagation delay between the UE and the RIS is small, for example because the UE 1404 and the RIS 1406 are close to each other, the reflected SRS may reach the UE 1404 within the cyclic prefix (CP) length. In that scenario, the UE 1404 needs to activate its receiver to receive the reflected SRS at the same time that its transmitter is active to transmit the original SRS, which results in strong self-interference and uses more power than using only a transmitter or only a receiver. Another reason is that the UE 1404 may receive the SRS reflected from the environment before receiving the SRS reflected by the RIS 1406, and therefore cannot distinguish between multipath reflections and RIS reflections. One approach to control this problem is shown in FIG. 16.

[0166]

[0171] 16 is a signaling and event diagram 1600 for RIS beam sweeping of SRS for UE-based AoD positioning according to some aspects of the disclosure, including controlling when the RIS 1406 transmits reflected signals. In this approach, there is an association between SRS resources and downlink slots or symbols used to reflect SRS signals received by the RIS 1406 during the SRS resources, which may be provided to the UE 1404 via SRS configuration 1602 and to the RIS 1406 via SRS settings 1604. 16, all SRS signals (e.g., SRS1 1606, SRS2 1608, SRS3 1610, SRS4 1612, SRS5 1614, SRS6 1616, ...) are transmitted before the RIS 1406 reflects them as SRS1' 1618, SRS2' 1620, SRS3' 1622, SRS4' 1624, SRS5' 1626, and SRS6' 1628, although in other aspects, each reflected SRS may be transmitted by the RIS 1406 before the UE 1404 transmits the next SRS signal, but during a designated DL slot or symbol. Other implementations are possible, such as transmitting one or more SRS signals by the UE 1404, transmitting one or more reflected SRS signals by the RIS 1406, and transmitting one or more remaining SRS signals by the UE 1404. These examples are illustrative and not limiting.

[0167]

[0172] In some aspects, for each SRS resource, its RIS reflection time, e.g., the delay between the time the RIS 1406 receives the SRS and the time the RIS 1406 transmits the reflected signal, should be controlled to ensure that the UE can observe the reflected SRS resource in a particular DL slot or DL ​​symbol. Since the gNB knows the exact propagation time from the gNB to the RIS, it can configure the SRS reflection time of the RIS to ensure that the RIS is reflected in the associated DL symbol time span. In some aspects, the SRS reflection timing error should be within the CP to avoid inter-symbol interference.

[0168]

[0173] In some aspects, rather than specifying a delay value, a particular DL slot or symbol may be identified as the location in time where the RIS 1406 should transmit a particular SRS signal. Because DL slots or symbols normally reserved for use by the gNB to transmit to the UE are instead used by the RIS, in some aspects the UE may be signaled with a special slot format, e.g., one or more particular DL symbols are dedicated to receiving particular SRS resources. The gNB does not transmit DL signals in these particular DL symbols. In this approach, the SRS resources are associated, for example, with a particular DL symbol time span and not associated with a particular DL reference signal or data / control channel.

[0169]

[0174] In some aspects, the UE may be provided with assistance data including the "expected time to receive SRS resource" and the "uncertainty of expected time to receive SRS resource" for the arriving SRS resource configured for AoD estimation. For example, the assistance data may be similar to the "expected RSTD" and "expected RSTD uncertainty" associated with each pair of TRPs transmitting PRS. In some aspects, the "expected time to receive SRS resource" may be derived from the configuration of the SRS and the time difference of the RIS between reception and reflection of the waveform. In some aspects, the "uncertainty of expected time to receive SRS resource" may be derived from the location of the RIS and the coverage range of the cell. If assistance data is included, it may be signaled from the LMF or gNB to the UE.

[0170]

[0175] In some aspects, the UE may use a wide angle beam for SRS transmission since the UE may not know the relative angle with the RIS prior to the positioning operation. In some aspects, the UE may adjust the angle of the SRS transmission beam depending on how well the location of the RIS is known to the UE, e.g., start with a wide beam to obtain an initial position estimate, and use a narrower beam for subsequent use, e.g., to improve the SINR of the SRS relative to the RIS.

[0171]

[0176] The technique of using the RIS to beam sweep the reflected SRS originally transmitted by the UE can be used for both UE-assisted and UE-based positioning modes. In the UE-assisted mode, the UE can measure the RSRP for each SRS and report them to the LMF via the LPP protocol, where the corresponding AoD is estimated and position calculation is performed. In the UE-based mode, the UE can measure the RSRP for each SRS and calculate the UE position with additional assistance data. These assistance data can include the RIS geographic location, the RIS orientation (to calculate the boresight direction), the azimuth and elevation angles of the RIS reflected SRS beam, the beamwidth of the RIS reflected SRS beam, and the boresight direction / beamwidth uncertainty. For example, the beamwidth can be 3 dB beamwidth, 6 dB beamwidth, or 12 dB beamwidth and can be specified with respect to a particular spatial dimension, such as azimuth or elevation. The boresight / beamwidth uncertainty can be a 0.5 dB, 1 dB, or 3 dB based measurement and can also be specified with respect to a particular spatial dimension.

[0172]

[0177] In the above detailed description, it can be seen that various features are grouped together in each example. This manner of disclosure should not be understood as an intention that the exemplary clauses have more features than are expressly stated in each clause. Rather, various aspects of the disclosure may include fewer than all features of each disclosed exemplary clause. Thus, the following clauses should be considered to be incorporated in the description, and each clause may stand alone as a separate example. Although each dependent clause may refer to a specific combination with one of the other clauses in the clause, the aspects of that dependent clause are not limited to that specific combination. It will be understood that other exemplary clauses may also include combinations of aspects of the dependent clause with the subject matter of any other dependent clause or independent clause, or any combination of features with other dependent clauses and independent clauses. Unless a specific combination is not intended (e.g., conflicting aspects such as defining an element as both an insulator and a conductor) is expressly expressed or can be easily inferred, the various aspects disclosed herein expressly include these combinations. It is further contemplated that aspects of a clause may be included in any other independent clause, even if the clause is not directly dependent on the independent clause.

[0173]

[0178] The following numbered clauses describe example implementations.

[0174]

[0179] Clause 1. A method of wireless communications performed by a user equipment (UE), comprising: obtaining configuration information identifying resources for sounding reference signal (SRS) positioning; transmitting a plurality of SRS transmissions to a reconfigurable intelligent surface (RIS) at different times in accordance with the configuration information; receiving a plurality of SRS transmissions from the RIS including reflections of the plurality of SRS transmissions to the RIS, each of the plurality of SRS transmissions from the RIS being transmitted at a different angle of departure (AoD) from the RIS; measuring each of the plurality of SRS transmissions from the RIS to generate a plurality of measurements; and performing a positioning operation based on the plurality of measurements.

[0175]

[0180] Clause 2. The method of clause 1, wherein obtaining the configuration information includes receiving the configuration information via radio resource control (RRC) signaling.

[0176]

[0181] Clause 3. The method of any of clauses 1 to 2, wherein obtaining the configuration information includes receiving the configuration information from a network entity.

[0177]

[0182] Clause 4. The method of clause 3, wherein receiving the configuration information from the network entity includes receiving the configuration information from a location server.

[0178]

[0183] Clause 5. Any of the methods of clauses 1-4, wherein the configuration information indicates a number of SRS resources, a time to transmit an SRS transmission to the RIS, an expected time to receive a reflection of the SRS transmission from the RIS, an uncertainty in the expected time to receive a reflection of the SRS transmission from the RIS, or a combination thereof.

[0179]

[0184] Clause 6. The method of any of clauses 1 to 5, wherein each of a plurality of SRS transmissions from the RIS is received at a known time or with a known delay after sending a corresponding SRS transmission to the RIS according to configuration information.

[0180]

[0185] Clause 7. The method of any of clauses 1-6, wherein each of the plurality of SRS transmissions from the RIS includes information associating each of the plurality of SRS transmissions with a corresponding SRS transmission of the plurality of SRS transmissions to the RIS.

[0181]

[0186] Clause 8. The method of clause 7, wherein the information includes an SRS ID, a beam ID, a known sequence, or a combination thereof.

[0182]

[0187] Clause 9. The method of any of clauses 1 to 8, wherein performing a positioning operation based on the plurality of measurements includes transmitting the plurality of measurements to a location server.

[0183]

[0188] Clause 10. The method of clause 9, further comprising receiving a position estimate from a location server based on the plurality of measurements.

[0184]

[0189] Clause 11. The method of any of clauses 1 to 10, wherein performing a positioning operation based on the plurality of measurements includes determining an AoD of the UE from the RIS based on the plurality of measurements.

[0185]

[0190] Clause 12. The method of clause 11, further comprising receiving assistance data including a geographic location of the RIS, an orientation of the RIS, characteristics of a reflected SRS beam, or a combination thereof, and determining the AoD of the UE from the RIS based on the multiple measurements comprises determining the AoD based on the multiple measurements and the assistance data.

[0186]

[0191] Clause 13. The method of clause 12, wherein the characteristics of the reflected SRS beam include an azimuth angle or beamwidth, an elevation angle or beamwidth, a boresight direction uncertainty, a beamwidth uncertainty, a transmission time uncertainty, or a combination thereof.

[0187]

[0192] Clause 14. The method of any of clauses 11 to 13, further comprising estimating a position of the UE based on the AoD and a distance from the UE to the RIS.

[0188]

[0193] Clause 15. A method of wireless communications performed by a reconfigurable intelligent surface (RIS), comprising: obtaining configuration information identifying resources for sounding reference signal (SRS) positioning; receiving a plurality of SRS transmissions at different times from a user equipment (UE); and transmitting a plurality of SRS transmissions including reflections of the plurality of SRS transmissions received from the UE, each of the plurality of SRS transmissions from the RIS being transmitted at a different angle of departure (AoD) from the RIS in accordance with the configuration information.

[0189]

[0194] Clause 16. The method of clause 15, wherein obtaining the configuration information includes receiving the configuration information via radio resource control (RRC) signaling.

[0190]

[0195] Clause 17. The method of any of clauses 15 to 16, wherein obtaining the configuration information includes receiving the configuration information from a network entity.

[0191]

[0196] Clause 18. The method of clause 17, wherein receiving the configuration information from the network entity includes receiving the configuration information from a location server.

[0192]

[0197] Clause 19. Any of the methods of clauses 15 to 18, wherein the configuration information indicates a number of SRS resources, an expected time to receive an SRS transmission from the UE, an uncertainty in the expected time to receive an SRS transmission from the UE, an expected time to transmit a reflection of the SRS transmission from the UE to the UE, an AoD to transmit a reflection of the SRS transmission from the UE, or a combination thereof.

[0193]

[0198] Clause 20. The method of any of clauses 15 to 19, wherein each of the plurality of SRS transmissions including a reflection of the plurality of SRS transmissions received from the UE includes information associating each of the plurality of SRS transmissions with a corresponding SRS transmission of the plurality of SRS transmissions received from the UE.

[0194]

[0199] Clause 21. The method of clause 20, wherein the information includes an SRS ID, a beam ID, a known sequence, or a combination thereof.

[0195]

[0200] Clause 22. A method of wireless communications performed by a location server, comprising: transmitting, to a reconfigurable intelligent surface (RIS), first configuration information identifying resources for sounding reference signal (SRS) positioning; and transmitting, to a user equipment (UE), second configuration information identifying resources for sounding reference signal (SRS) positioning, wherein each of the first configuration information and the second configuration information indicates a number of SRS resources, a time at which the UE will transmit an SRS transmission to the RIS, an expected time at which the UE will receive a reflection of the SRS transmission from the RIS, an uncertainty in the expected time at which the UE will receive a reflection of the SRS transmission from the RIS, an angle of departure (AoD) at which the RIS transmits a reflection of the SRS transmission from the UE, or a combination thereof.

[0196]

[0201] Clause 23. The method of clause 22, further comprising transmitting assistance data to the UE, the assistance data including a geographic location of the RIS, an orientation of the RIS, characteristics of a reflected SRS beam, or a combination thereof.

[0197]

[0202] Clause 24. The method of clause 23, wherein the characteristics of the reflected SRS beam include an azimuth angle or beamwidth, an elevation angle or beamwidth, an uncertainty in boresight direction, an uncertainty in beamwidth, an uncertainty in time of transmission, or a combination thereof.

[0198]

[0203] Clause 25. The method of any of clauses 22 to 24, further comprising: receiving from the UE a plurality of Reference Signal Received Power (RSRP) values ​​corresponding to a plurality of reflected SRS transmissions measured by the UE; determining an AoD of the UE from the RIS based on the plurality of RSRP values; estimating a position of the UE based at least in part on the AoD; and transmitting the estimated position to the UE.

[0199]

[0204] Clause 26. An apparatus comprising a memory, at least one transceiver, and at least one processor communicatively coupled to the memory and the at least one transceiver, wherein the memory, the at least one transceiver, and the at least one processor are configured to perform a method according to any of clauses 1 to 25.

[0200]

[0205] Item 27. An apparatus comprising means for carrying out the method according to any one of items 1 to 25.

[0201]

[0206] Clause 28. A non-transitory computer-readable medium storing computer-executable instructions, the computer-executable instructions including at least one instruction for causing a computer or processor to perform a method according to any one of clauses 1 to 25.

[0202]

[0207] Those skilled in the art will appreciate that information and signals may be represented using any of a variety of different technologies and techniques. For example, the data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0203]

[0208] Moreover, those skilled in the art will appreciate that the various exemplary logic blocks, modules, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability of hardware and software, various exemplary components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the particular application and design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

[0204]

[0209] The various example logic blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed using a general purpose processor, a digital signal processor (DSP), an ASIC, a field-programmable gate array (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. A general purpose processor may be a microprocessor, but alternatively, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0205]

[0210] 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. The software module may reside in a random access memory (RAM), a flash memory, a read-only memory (ROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. Alternatively, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal (e.g., UE). Alternatively, the processor and the storage medium may reside as discrete components in a user terminal.

[0206]

[0211] In one or more exemplary aspects, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted via a computer-readable medium as one or more instructions or code. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage medium may be any available medium that can be accessed by a computer. By way of example, and not limitation, such computer-readable media may 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. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included within the definition of media. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, and Blu-ray disc, where disks typically reproduce data magnetically and discs reproduce data optically using lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0207]

[0212] Although the above disclosure illustrates exemplary aspects of the disclosure, it should be noted that various changes and modifications may be made herein without departing from the scope of the disclosure as defined by the appended claims. The functions, steps, and / or actions of the method claims according to the aspects of the disclosure described herein do not have to be performed in any particular order. Further, although elements of the disclosure may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated.

Claims

1. 1. A method of wireless communication performed by a user equipment (UE), comprising: Obtaining configuration information identifying resources for sounding reference signal (SRS) positioning; transmitting a plurality of SRS transmissions to a reconfigurable intelligent surface (RIS) at different times according to the configuration information; receiving a plurality of SRS transmissions from the RIS comprising reflections of the plurality of SRS transmissions to the RIS, wherein each of the plurality of SRS transmissions from the RIS is transmitted at a different Angle of Departure (AoD) from the RIS; measuring each of the plurality of SRS transmissions from the RIS to generate a plurality of measurements; performing a positioning operation based on the plurality of measurements; and A method comprising:

2. Obtaining the configuration information comprises receiving the configuration information via Radio Resource Control (RRC) signaling; and / or Obtaining the configuration information comprises receiving the configuration information from a network entity; and optionally receiving the configuration information from the network entity comprises receiving the configuration information from a location server. The method of claim 1.

3. The configuration information indicates a number of SRS resources, a time to transmit an SRS transmission to the RIS, an expected time to receive a reflection of the SRS transmission from the RIS, an uncertainty in an expected time to receive a reflection of the SRS transmission from the RIS, or a combination thereof; Each of the plurality of SRS transmissions from the RIS is received at a known time or with a known delay after sending a corresponding SRS transmission to the RIS in accordance with the configuration information; and / or Each of the plurality of SRS transmissions from the RIS comprises information associating each of the plurality of SRS transmissions with a corresponding SRS transmission of the plurality of SRS transmissions to the RIS, and optionally 2. The method of claim 1, wherein the information comprises an SRS ID, a beam ID, a known sequence, or a combination thereof.

4. performing the positioning operation based on the plurality of measurements comprises transmitting the plurality of measurements to a location server; The method of claim 1 , further comprising receiving a position estimate based on the plurality of measurements from the location server.

5. The method of claim 1 , wherein performing the positioning operation based on the plurality of measurements comprises determining an AoD of the UE from the RIS based on the plurality of measurements.

6. receiving assistance data comprising a geographic location of the RIS, an orientation of the RIS, characteristics of a reflected SRS beam, or a combination thereof; Determining the AoD of the UE from the RIS based on the plurality of measurements comprises determining the AoD based on the plurality of measurements and the assistance data; and optionally The characteristics of the reflected SRS beam comprise an azimuth angle, an azimuth beamwidth, an elevation angle, an elevation beamwidth, a boresight direction uncertainty, a beamwidth uncertainty, a transmission time uncertainty, or a combination thereof. The method according to claim 5.

7. The method of claim 5 , further comprising estimating a location of the UE based on the AoD and a distance from the UE to the RIS.

8. 1. A method of wireless communication performed by a reconfigurable intelligent surface (RIS), comprising: Obtaining configuration information identifying resources for sounding reference signal (SRS) positioning; receiving a plurality of SRS transmissions at different times from a user equipment (UE); receiving a plurality of SRS transmissions comprising reflections of the plurality of SRS transmissions received from the UE, wherein each of the plurality of SRS transmissions from the RIS is transmitted at a different Angle of Departure (AoD) from the RIS according to the configuration information; A method comprising:

9. Obtaining the configuration information comprises receiving the configuration information via Radio Resource Control (RRC) signaling; and / or obtaining the configuration information comprises receiving the configuration information from a network entity; Optionally, receiving the configuration information from the network entity comprises receiving the configuration information from a location server. The method according to claim 8.

10. The configuration information indicates a number of SRS resources, an expected time to receive an SRS transmission from the UE, an uncertainty in the expected time to receive the SRS transmission from the UE, an expected time to transmit a reflection of the SRS transmission from the UE to the UE, an AoD for transmitting a reflection of the SRS transmission from the UE, or a combination thereof; and / or Each of the plurality of SRS transmissions comprising a reflection of the plurality of SRS transmissions received from the UE comprises information associating each of the plurality of SRS transmissions with a corresponding one of the plurality of SRS transmissions received from the UE, and optionally The information comprises an SRS ID, a beam ID, a known sequence, or a combination thereof. The method according to claim 8.

11. 1. A method of wireless communication performed by a location server, comprising: transmitting, to a reconfigurable intelligent surface (RIS), first configuration information identifying resources for sounding reference signal (SRS) positioning; transmitting, to a user equipment (UE), second configuration information identifying resources for SRS positioning; Equipped with Each of the first configuration information and the second configuration information indicates an expected time for the UE to receive a reflection of the SRS transmission from the RIS, an uncertainty in an expected time for the UE to receive a reflection of the SRS transmission from the RIS, or a combination thereof. method.

12. 12. The method of claim 11, further comprising transmitting assistance data to the UE comprising a geographic location of the RIS, an orientation of the RIS, characteristics of a reflected SRS beam, or a combination thereof, and optionally, the characteristics of the reflected SRS beam comprise an azimuth angle, an azimuth beamwidth, an elevation angle, an elevation beamwidth, a boresight direction uncertainty, a beamwidth uncertainty, a transmission time uncertainty, or a combination thereof.

13. receiving from the UE a plurality of reference signal received power (RSRP) values ​​corresponding to a plurality of reflected SRS transmissions measured by the UE; determining an AoD of the UE from the RIS based on the plurality of RSRP values; estimating a location of the UE based at least in part on the AoD; and transmitting the estimated location to the UE; and The method of claim 11 further comprising:

14. A user equipment (UE), 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 comprising: Obtaining configuration information identifying resources for sounding reference signal (SRS) positioning; Transmitting a plurality of SRS transmissions to a reconfigurable intelligent surface (RIS) via the at least one transceiver at different times according to the configuration information; receiving, via the at least one transceiver, a plurality of SRS transmissions from the RIS comprising reflections of a plurality of SRS transmissions to the RIS, wherein each of the plurality of SRS transmissions from the RIS is transmitted at a different Angle of Departure (AoD) from the RIS; measuring each of the plurality of SRS transmissions from the RIS to generate a plurality of measurements; performing a positioning operation based on the plurality of measurements; The UE is configured to:

15. A reconfigurable intelligent surface (RIS), comprising: 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 comprising: Obtaining configuration information identifying resources for sounding reference signal (SRS) positioning; receiving a plurality of SRS transmissions at different times from a user equipment (UE) via the at least one transceiver; transmitting a plurality of SRS transmissions via the at least one transceiver, the plurality of SRS transmissions comprising reflections of the plurality of SRS transmissions received from the UE; It is structured as follows: each of the plurality of SRS transmissions from the RIS is transmitted at a different Angle of Departure (AoD) from the RIS according to the configuration information. R I S.

16. A location server, 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 comprising: transmitting, via the at least one transceiver, to a reconfigurable intelligent surface (RIS), first configuration information identifying resources for sounding reference signal (SRS) positioning; transmitting, via the at least one transceiver, to a user equipment (UE), second configuration information identifying resources for SRS positioning; It is structured as follows: Each of the first configuration information and the second configuration information indicates an expected time for the UE to receive a reflection of the SRS transmission from the RIS, an uncertainty in an expected time for the UE to receive a reflection of the SRS transmission from the RIS, or a combination thereof. Location Server.

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