Opportunistic RF Sensing in Cellular Systems

Abstract

Techniques for radio frequency (RF) sensing are disclosed. In one aspect, a network entity, such as a base station, can identify an opportunity for RF sensing during which a user equipment (UE) does not transmit a signal, where the opportunity includes a guard period of the UE, a bandwidth part (BWP) switching period of the UE, or a beam switching period of the UE. The network entity can transmit an RF sensing signal, receive an RF sensing signal, or do both during the opportunity for RF sensing. In one aspect, the UE can determine an opportunity for a network entity to perform RF sensing while the UE does not transmit a signal, where the opportunity includes a guard period of the UE, a BWP switching period of the UE, or a beam switching period of the UE. The UE can indicate the opportunity for RF sensing to the network entity.

Description

Background Art

[0001] 1. Technical Field

[0001] Aspects of the present disclosure generally relate to wireless communication.

[0002] 2. Description of Related Art

[0002] Wireless communication systems have evolved through various generations, including first-generation (1G) analog wireless telephone service, second-generation (2G) digital wireless telephone service (including interim 2.5G and 2.75G networks), third-generation (3G) high-speed data, Internet-capable 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), enables, among other improvements, higher data transfer speeds, a greater number of connections, and better coverage. According to the Next Generation Mobile Networks Alliance, the 5G standard is designed to provide higher data rates, more accurate positioning (e.g., based on positioning reference signals (PRS) such as downlink, uplink or sidelink positioning reference signals, reference signals for positioning (RS-P)), and other technical enhancements compared to previous standards. These enhancements enable highly accurate 5G-based positioning, similar to the use of higher frequency bands, advancements in PRS processes and technologies, and high-density deployments for 5G.

Summary of the Invention

[0004]

[0004] The following presents a simplified summary of one or more aspects disclosed herein. Accordingly, the following summary should not be considered an extensive overview of all contemplated aspects, nor should the following summary be regarded as identifying key or critical elements of all contemplated aspects or as delineating the scope of any particular aspect. Thus, the sole purpose of the following summary is to present, in a simplified form, certain concepts related to one or more aspects of the mechanisms disclosed herein prior to the detailed description presented below.

[0005]

[0005] In one aspect, a method for radio frequency (RF) sensing performed by a network entity, such as a base station (BS), is to identify an opportunity for RF sensing during which a user equipment (UE) does not transmit a signal, where the opportunity includes a guard period of the UE, a bandwidth part (BWP) switching period of the UE, or a beam switching period of the UE, and to transmit an RF sensing signal, receive an RF sensing signal, or do both during the opportunity for RF sensing.

[0006]

[0006] In one aspect, a method for RF sensing performed by a UE is to determine an opportunity for a base station to perform RF sensing while the UE does not transmit a signal, where the opportunity includes a guard period of the UE, a BWP switching period of the UE, or a beam switching period of the UE, and to indicate the opportunity for RF sensing to the base station.

[0007]

[0007] In one aspect, a network entity includes a memory, at least one transceiver, and at least one processor communicatively coupled to the memory and the at least one transceiver, where the at least one processor is configured to identify an opportunity for RF sensing during which a UE does not transmit a signal, where the opportunity includes a guard period of the UE, a BWP switching period of the UE, or a beam switching period of the UE, and to transmit an RF sensing signal, receive an RF sensing signal, or do both during the opportunity for RF sensing via the at least one transceiver.

[0008]

[0008] In one aspect, the UE comprises a memory, at least one transceiver, and at least one processor communicatively coupled to the memory and the at least one transceiver, and the at least one processor determines an opportunity for the base station to perform RF sensing while the UE is not transmitting a signal, the opportunity including a guard period of the UE, a BWP switching period of the UE, or a beam switching period of the UE, and is configured to instruct the base station via the at least one transceiver of the opportunity for RF sensing.

[0009]

[0009] In one aspect, the base station includes means for identifying an opportunity for RF sensing while the UE is not transmitting a signal, the opportunity including a guard period of the UE, a BWP switching period of the UE, or a beam switching period of the UE, and means for transmitting an RF sensing signal, receiving an RF sensing signal, or both, during the opportunity for RF sensing.

[0010]

[0010] In one aspect, the UE includes means for determining an opportunity for the base station to perform RF sensing while the UE is not transmitting a signal, the opportunity including a guard period of the UE, a BWP switching period of the UE, or a beam switching period of the UE, and means for instructing the base station of the opportunity for RF sensing.

[0011]

[0011] In one aspect, when executed by the base station, a non-transitory computer-readable medium storing computer-executable instructions that cause the base station to identify an opportunity for RF sensing while the UE is not transmitting a signal, the opportunity including a guard period of the UE, a BWP switching period of the UE, or a beam switching period of the UE, and to transmit an RF sensing signal, receive an RF sensing signal, or both, during the opportunity for RF sensing.

[0012]

[0012] In one aspect, when executed by a UE, the UE is caused to determine an opportunity for a base station to perform RF sensing while the UE is not transmitting a signal, the opportunity including a guard period of the UE, a BWP switching period of the UE, or a beam switching period of the UE, and to instruct the base station of the opportunity for RF sensing. A non-transitory computer-readable medium storing computer-executable instructions.

[0013]

[0013] Other objects and advantages related to the aspects disclosed herein will be apparent to those skilled in the art based on the accompanying drawings and the detailed description.

Brief Description of the Drawings

[0014]

[0014] The accompanying drawings are presented to assist in the description of various aspects of the present disclosure and are provided only for purposes of illustration of the aspects and not limitation thereof.

Figure 1

[0015] A diagram illustrating an exemplary wireless communication system according to an aspect of the present disclosure.

Figure 2A

[0016] An exemplary wireless network structure according to an aspect of the present disclosure is shown.

Figure 2B

Figure 3A

[0017] A simplified block diagram of some exemplary aspects of components that may be employed in a user equipment (UE) and configured to support the communications taught herein.

Figure 3B

Figure 3C

Figure 4A

[0018] A diagram illustrating an exemplary monostatic radar system.

Figure 4B

[0019] It is a diagram showing an exemplary bistatic radar system.

Figure 5

[0020] It shows exemplary distance calculation using a bistatic or multistatic radar.

Figure 6

[0021] It is a time and frequency diagram showing an exemplary guard period in which the UE does not transmit any other signals at all.

Figure 7

[0022] It is a time and frequency diagram 700 showing an exemplary BWP switching period in which the UE does not transmit any other signals at all.

Figure 8

[0023] It shows an example of beam switching by the base station and the UE in which the UE does not transmit any other signals at all.

Figure 9

[0024] It is a flowchart of an exemplary process executed by a base station or other network entity associated with opportunistic RF sensing in a cellular system.

Figure 10

[0025] It is a flowchart of an exemplary process executed by the UE associated with opportunistic RF sensing in a cellular system.

Mode for Carrying Out the Invention

[0015]

[0026] Techniques for radio frequency (RF) sensing are disclosed. In one aspect, a network entity, such as a base station, may identify an opportunity for RF sensing during which a user equipment (UE) does not transmit a signal, the opportunity including a guard period of the UE, a bandwidth part (BWP) switching period of the UE, or a beam switching period of the UE. The network entity may transmit an RF sensing signal, receive an RF sensing signal, or do both during the opportunity for RF sensing. In one aspect, the UE may determine an opportunity for the network entity to perform RF sensing while the UE does not transmit a signal, the opportunity including a guard period of the UE, a BWP switching period of the UE, or a beam switching period of the UE. The UE may indicate the opportunity for RF sensing to the network entity.

[0016]

[0027] Aspects of the present disclosure are provided in the following description and associated drawings directed to various examples 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 are not described in detail or are omitted so as not to obscure the relevant details of the present disclosure.

[0017]

[0028] As used herein, the terms “exemplary” and / or “example” are used 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. Similarly, the term “aspect of the present disclosure” does not necessarily require that all aspects of the present disclosure include the recited features, advantages, or modes of operation.

[0018]

[0029] One of ordinary skill 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 referred to throughout the following description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof, depending in part on the particular application, desired design, corresponding technology, and the like.

[0019]

[0030] Furthermore, many aspects will be described from the perspective of sequences of actions to be performed, for example, by elements of a computing device. It will be recognized that the various actions described herein can be implemented by a specific circuit (e.g., application specific integrated circuits (ASICs)), by program instructions executed by one or more processors, or by a combination of both. Additionally, the sequence(s) of actions described herein can be considered to be fully embodied within any form of non-transitory computer-readable storage medium that stores a corresponding set of computer instructions that, when executed, cause the relevant processor(s) of the device to perform or cause to be performed the functionality described herein. Accordingly, the various aspects of the present disclosure can be embodied in several different forms, all of which are intended to fall within the scope of the claimed subject matter. Additionally, for each of the aspects described herein, a corresponding form of any such aspect can be described herein, for example, as “logic configured to” perform the described action.

[0020]

[0031] As used herein, the terms "user equipment" (UE) and "base station" are not intended to be specific to, or limited to, any particular radio access technology (RAT) unless otherwise specified. Generally, a UE can be any wireless communication device used by a user to communicate via a wireless communication network (e.g., a mobile phone, a router, a tablet computer, a laptop computer, a consumer location device, a wearable (e.g., a smartwatch, 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.). The UE can be mobile or (e.g., at a certain time) stationary and can communicate with a radio access network (RAN). The term "UE" as used herein may be interchangeably referred to as "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 variants thereof. Generally, the UE can communicate with a core network via the RAN, and through the core network, the UE can be connected to an external network 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 the 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.).

[0021]

[0032] The base station may operate according to one of several RATs that the base station is communicating with the UE according to the network in which the base station is deployed. Alternatively, it may be called an access point (AP), network node, Node B, evolved Node B (eNB), next generation eNB (ng-eNB), new radio (NR) Node B (also called gNB or g-node B), etc. The base station can be mainly used to support wireless access by the UE, including supporting data, voice, and / or signaling connections for the supported UE. In some systems, the base station may provide only the edge node signaling function, while in other systems, the base station may provide additional control and / or network management functions. The communication link through which the UE can send signals to the base station is called the uplink (UL) channel (e.g., reverse traffic channel, reverse control channel, access channel, etc.). The communication link through which the base station can transmit signals to the UE can be called the downlink (DL) channel or the forward link channel (e.g., paging channel, control channel, broadcast channel, forward traffic channel, etc.). The term traffic channel (TCH) used in this specification may refer to either the uplink / reverse traffic channel or the downlink / forward traffic channel.

[0022]

[0033] 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, that physical TRP may be the antenna of the base station corresponding to the cell (or some cell sectors) of the base station. When the term "base station" refers to multiple collocated physical TRPs, the physical TRPs may be an array of antennas of the base station (such as in 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 TRPs may be a distributed antenna system (DAS) (a network of spatially separated antennas connected to a common source via a transport medium), or a remote radio head (RRH) (a remote base station connected to a serving base station). Alternatively, the non-collocated physical TRPs may be the serving base station that receives measurement value reports from the UE and neighboring base stations whose reference radio frequency (RF) signals the UE is measuring. Since a TRP is the point from which the base station transmits and receives wireless signals, references to transmissions from the base station or receptions at the base station as used herein should be understood to refer to a specific TRP of the base station.

[0023]

[0034] In some implementations that support UE positioning, the base station may not support wireless access by the UE (e.g., may not support a data connection, a voice connection, and / or a signaling connection for the UE), but instead may send to the UE a reference signal that will be measured by the UE and / or may receive and measure a signal sent by the UE. Such a base station may be referred to as a positioning beacon (e.g., when sending a signal to the UE) and / or a location measurement unit (e.g., when receiving and measuring a signal from the UE).

[0024]

[0035] An "RF signal" includes an electromagnetic wave of a given frequency that propagates information through the space between a transmitter and a receiver. A transmitter as used herein may send a single "RF signal" or multiple "RF signals" to a receiver. However, due to the propagation characteristics of the RF signal through a multipath channel, the receiver may receive multiple "RF signals" corresponding to each transmitted RF signal. The same RF signal transmitted via different paths between the transmitter and the receiver may be referred to as a "multipath" RF signal. An RF signal as used herein may also be referred to as a "wireless signal" or simply a "signal" when the context makes it clear that the term "signal" refers to a wireless signal or an RF signal.

[0025]

[0036] FIG. 1 shows an exemplary wireless communication system 100 according to an aspect of the present disclosure. (Sometimes referred to as a wireless wide area network (WWAN)) The wireless communication system 100 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 one aspect, the macrocell base stations may include an eNB and / or ng-eNB corresponding to an LTE network for the wireless communication system 100, or a gNB corresponding to an NR network for the wireless communication system 100, or a combination of both, and the small cell base stations may include femtocells, picocells, microcells, and the like.

[0026]

[0037] The base station 102 may collectively form the RAN and interface with the core network 170 (e.g., evolved packet core (EPC) or 5G core (5GC)) through the backhaul link 122 and, through the core network 170, with one or more location servers 172 (e.g., location management function (LMF) or secure user plane location (SUPL) location platform (SLP)). The location server(s) 172 may be part of the core network 170 or may be external to the core network 170. The location server 172 may be integrated with the base station 102. 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 via the base station 102 currently serving the UE 104. The UE 104 may also communicate with the location server 172 via another network, such as via a wireless local area network (WLAN) access point (AP) (e.g., AP 150 described below) via an application server (not shown), etc., or via another path. For signaling purposes, the communication between the UE 104 and the location server 172 may be represented as an indirect connection (e.g., through the core network 170, etc.) or a direct connection (e.g., as shown via the direct connection 128), and intervening nodes (if any) are omitted from the signaling diagram for clarity.

[0027]

[0038] In addition to other functions, the base station 102 may perform one or more functions related to transferring user data, wireless 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 distribution, non-access stratum (NAS) message delivery, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS), subscriber and device trace, RAN information management (RIM), paging, positioning, and warning message delivery. The base stations 102 may communicate with each other directly or indirectly (e.g., through the EPC / 5GC) via a backhaul link 134, which may be wired or wireless.

[0028]

[0039] The base station 102 can wirelessly communicate with the UE 104. Each of the base stations 102 can provide communication coverage regarding its respective geographic coverage area 110. In one aspect, one or more cells can be supported by the base stations 102 within each geographic coverage area 110. A "cell" is a logical communication entity used for communication with a base station (e.g., via several frequency resources such as those referred to as 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.) for distinguishing cells operating via the same or different carrier frequencies. In some cases, different cells can be configured according to different protocol types (e.g., machine-type communication (MTC), narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB), or others) that can provide access to different types of UEs. Since a cell is supported by a specific base station, the term "cell" may, depending on the context, refer to one or both of the logical communication entity and the base station that supports it. Additionally, since the TRP is typically the physical transmission point of a cell, the terms "cell" and "TRP" may be used interchangeably. In some cases, the term "cell" may also refer to the geographic coverage area (e.g., sector) of a base station as long as a carrier frequency can be detected and used for communication within a certain part of the geographic coverage area 110.

[0029]

[0040] The geographical coverage area 110 of the neighboring macro cell base station 102 may partially overlap (e.g., in a handover area), and some of the geographical coverage areas 110 may be significantly overlapped by a larger geographical coverage area 110. For example, a small cell base station 102’ (labeled as “SC” for “small cell”) may have a geographical coverage area 110’ that significantly overlaps with the geographical coverage areas 110 of one or more macro cell base stations 102. A network including both small cell base stations and macro cell base stations may be known as a heterogeneous network. A heterogeneous network may also include home eNBs (HeNBs) that may provide services to a limited group known as a closed subscriber group (CSG).

[0030]

[0041] The communication link 120 between the base station 102 and the UE 104 may include uplink (also called reverse link) transmission from the UE 104 to the base station 102 and / or downlink (DL) (also called forward link) transmission from the base station 102 to the UE 104. The communication link 120 may use MIMO antenna technology including spatial multiplexing, beamforming, and / or transmit diversity. The communication link 120 may be through one or more carrier frequencies. The carrier allocation 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).

[0031]

[0042] Wireless communication system 100 may further include a WLAN access point (AP) 150 that communicates with WLAN stations (STAs) 152 via 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 a listen before talk (LBT) procedure before communicating to determine whether the channel is available.

[0032]

[0043] Small cell base station 102’ may operate in a licensed frequency spectrum and / or an unlicensed frequency spectrum. When operating in the unlicensed frequency spectrum, the small cell base station 102’ may utilize LTE technology or NR technology and use the same 5 GHz unlicensed frequency spectrum as used by the WLAN AP 150. A small cell base station 102’ that employs LTE / 5G in the unlicensed frequency spectrum may expand the coverage to the access network and / or increase the capacity of the access network. NR in the unlicensed spectrum may be referred to as NR-U. LTE in the unlicensed spectrum may sometimes be referred to as LTE-U, licensed assisted access (LAA), or MulteFire.

[0033]

[0044] The wireless communication system 100 may further include an mmW base station 180 that communicates with the UE 182 and can operate at millimeter wave (mmW) frequencies and / or near mmW. Extremely high frequency (EHF) is a part 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 within this band can be called millimeter waves. Near mmW can drop down to a frequency of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band ranges from 3 GHz to 30 GHz and is also called centimeter waves. Communication using the mmW / near mmW radio frequency band has high path loss and a relatively short range. The mmW base station 180 and the UE 182 may utilize beamforming (transmission and / or reception) via the mmW communication link 184 to compensate for the extremely high path loss and short range. Further, in an alternative configuration, it will be understood that one or more base stations 102 may also transmit using mmW or near mmW and beamforming. Accordingly, it will be understood that the above examples are merely examples and should not be construed as limiting the various aspects disclosed herein.

[0034]

[0045] Transmission beamforming is a technique for concentrating RF signals in a specific direction. Conventionally, when a network node (e.g., a base station) broadcasts an RF signal, it broadcasts the signal in all directions (omnidirectionally). Using transmission beamforming, the network node determines where a given target device (e.g., a UE) is located with respect to the transmitting network node and transmits a stronger downlink RF signal in that specific direction, thereby providing a faster and more powerful RF signal to the receiving device(s) from the perspective of data rate. To vary the directivity 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 can create a beam of RF waves that can be "steered" to point in different directions without actually moving the antennas. Specifically, the RF currents from the transmitters are supplied to the individual antennas in appropriate phase relationships such that the radio waves from the separate antennas are combined to cancel out and suppress radiation in unwanted directions while increasing radiation in the desired direction.

[0035]

[0046] The transmitted beam may be quasi-collocated, which means that, regardless of whether the transmitting antennas of the network node itself are physically collocated, the received beam (e.g., UE) appears to have the same parameters. In NR, there are four types of quasi-co-location (QCL) relationships. Specifically, a given type of QCL relationship 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 of 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 of 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 of QCL type C, the receiver can use the source reference RF signal to estimate the Doppler shift and average delay of the second reference RF signal transmitted on the same channel. If the source reference RF signal is of QCL type D, the receiver can use the source reference RF signal to estimate the spatial reception parameters of the second reference RF signal transmitted on the same channel.

[0036]

[0047] In receive beamforming, a receiver uses a receive beam to amplify an RF signal detected on a given channel. For example, the receiver can increase the gain setting of an array of antennas in that direction and / or adjust the phase setting to amplify an RF signal received from a particular direction (e.g., increase its gain level). Thus, when a receiver is said to beamform in a certain direction, it means that the beam gain in that direction is higher than the beam gain 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 the RF signal received from that direction.

[0037]

[0048] Transmit beams and receive beams may be spatially related. Spatial relationship means that parameters for a second beam (e.g., a transmit beam or a receive beam) for a second reference signal can be derived from information about a first beam (e.g., a receive beam or a transmit beam) for a first reference signal. For example, a UE may receive a reference downlink reference signal (e.g., a synchronization signal block (SSB)) from a base station using a particular receive beam. The UE can then form a transmit beam for sending an uplink reference signal (e.g., a sounding reference signal (SRS)) to that base station based on the parameters of the receive beam.

[0038]

[0049] Note that the "downlink" beam can be either a transmission beam or a reception beam, depending on the entity that forms it. For example, when the base station forms a downlink beam to transmit a reference signal to the UE, the downlink beam is a transmission beam. However, when the UE forms a downlink beam, it is a reception beam for receiving the downlink reference signal. Similarly, the "uplink" beam can be either a transmission beam or a reception beam, depending on the entity that forms it. For example, when the base station forms an uplink beam, it is an uplink reception beam, and when the UE forms an uplink beam, it is an uplink transmission beam.

[0039]

[0050] The electromagnetic spectrum is often subdivided into various classes, bands, channels, etc. based on frequency / wavelength. In 5G NR, two initial operating bands are identified as frequency range designations FR1 (410 MHz to 7.125 GHz) and FR2 (24.25 GHz to 52.6 GHz). Although a portion of FR1 is higher than 6 GHz, it should be understood that FR1 is often (interchangeably) referred to as the "sub-6 GHz" band in various documents and papers. Similar nomenclature issues may arise with respect to FR2, which, although different from the extremely high frequency (EHF) band (30 GHz to 300 GHz) identified by the International Telecommunications Union (ITU) as the "millimeter wave" band, is often (interchangeably) referred to as the "millimeter wave" band in documents and papers.

[0040]

[0051] The frequency between FR1 and FR2 is often referred to as the intermediate band frequency. In recent 5G NR research, the operating band for these intermediate band frequencies is identified as frequency range designation FR3 (7.125 GHz to 24.25 GHz). The frequency bands included within FR3 may inherit FR1 characteristics and / or FR2 characteristics, and thus, in fact, may extend the characteristics of FR1 and / or FR2 to the intermediate band frequencies. Note that in order to extend 5G NR operation beyond 52.6 GHz, higher frequency bands are currently being explored. For example, three higher operating bands are identified as frequency range designations FR4a or FR4-1 (52.6 GHz to 71 GHz), FR4 (52.6 GHz to 114.25 GHz), and FR5 (114.25 GHz to 300 GHz). Each of these higher frequency bands is included within the EHF band.

[0041]

[0052] With the above aspects in mind, unless otherwise specifically described separately, terms such as "sub-6 GHz" when used in this specification may be understood to broadly represent frequencies that can be less than 6 GHz, can be within FR1, or can include the intermediate band frequency. Furthermore, unless otherwise specified, terms such as "millimeter wave" when used in this specification may be understood to broadly represent frequencies that can include the intermediate band frequency, frequencies that can be within the range of FR2, FR4, FR4-a or FR4-1, and / or FR5, or frequencies that can be within the range of the EHF band.

[0042]

[0053] 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 the carrier that operates on the primary frequency (e.g., FR1) used by the UE104 / 182 and the cell where the UE104 / 182 performs the initial radio resource control (RRC) connection establishment procedure or starts the RRC connection re-establishment procedure. The primary carrier carries all common control channels and UE-specific control channels and can be a carrier within the licensed frequency (however, it is not always the case). The secondary carrier can be configured when an RRC connection is established between the UE104 and the anchor carrier and is a carrier that operates on a second frequency (e.g., FR2) and can be used to provide additional radio resources. In some cases, the secondary carrier can be a carrier within the unlicensed frequency. Since both the primary uplink carrier and the primary downlink carrier are usually UE-specific, the secondary carrier is assumed to contain only the necessary signaling information and signals. For example, signaling information and signals that are UE-specific should not exist within the secondary carrier. This means that different UE104 / 182 within a cell can have different downlink primary carriers. The same applies to the uplink primary carrier. The network can change the primary carrier of any UE104 / 182 at any time. This is done, for example, to balance the load on different carriers. Terms such as "cell", "serving cell", "component carrier", "carrier frequency", etc. can be used interchangeably since the "serving cell" (regardless of PCell or SCell) corresponds to the carrier frequency / component carrier through which several base stations communicate.

[0043]

[0054] For example, still referring to FIG. 1, one of the frequencies utilized by macro cell base station 102 can be an anchor carrier (or "PCell"), and other frequencies utilized by macro cell base station 102 and / or mmW base station 180 can be secondary carriers ("SCells"). Simultaneous transmission and / or reception of multiple carriers enables UE104 / 182 to significantly increase its data transmission and / or reception rate. For example, two 20 MHz carriers aggregated within a multi-carrier system would, in theory, result in a two-fold increase in data rate (i.e., 40 MHz) compared to the data rate achieved by a single 20 MHz carrier.

[0044]

[0055] Wireless communication system 100 may further include a UE164 that may communicate with macro cell base station 102 via communication link 120 and / or with mmW base station 180 via mmW communication link 184. For example, macro cell base station 102 may support a PCell and one or more SCells for UE164, and mmW base station 180 may support one or more SCells for UE164.

[0045]

[0056] In some cases, UE164 and UE182 may be capable of sidelink communication. Sidelink-capable UEs (SL-UEs) can communicate with the base station 102 via a communication link 120 that uses the Uu interface (i.e., the air interface between the UE and the base station). The SL-UEs (e.g., UE164, UE182) may also communicate directly with each other via a wireless sidelink 160 that uses the PC5 interface (i.e., the air interface between sidelink-capable UEs). A wireless sidelink (or simply "sidelink") conforms to the core cellular (e.g., LTE, NR) standard that enables direct communication between two or more UEs without the need for communication to pass through a base station. Sidelink communication may be unicast or multicast, and can be used for device-to-device (D2D) media sharing, vehicle-to-vehicle (V2V) communication, vehicle-to-everything (V2X) communication (e.g., cellular V2X (cV2X) communication, enhanced V2X (eV2X) communication, etc.), emergency rescue applications, and the like. One or more of the groups of SL-UEs that utilize sidelink communication may be within the geographical coverage area 110 of the base station 102. Other SL-UEs in such a group may be outside the geographical coverage area 110 of the base station 102 or, in some cases, may not be able to receive transmissions from the base station 102. In some cases, the group of SL-UEs communicating via sidelink communication may utilize a one-to-many (1:M) system where each SL-UE transmits to all other SL-UEs within the group. In some cases, the base station 102 facilitates the scheduling of resources for sidelink communication. In other cases, sidelink communication is performed between SL-UEs without the involvement of the base station 102.

[0046]

[0057] In one aspect, the sidelink 160 may operate on a target wireless communication medium, and the associated communication medium may be shared with other wireless communications between other vehicles and / or infrastructure access points, and other RATs. The "medium" may be composed of one or more time, frequency, and / or spatial communication resources associated with wireless communication between one or more transmitter / receiver pairs (including, for example, one or more channels over one or more carriers). In one aspect, the target medium may correspond to at least a portion of an unlicensed frequency band shared among various RATs. Different licensed frequency bands are reserved for some communication systems (e.g., by a government agency such as the Federal Communications Commission (FCC) in the United States), but these systems, especially those employing small cell access points, have recently extended their operations to unlicensed frequency bands such as the Unlicensed National Information Infrastructure (U-NII) band used by wireless local area network (WLAN) technologies, most notably the IEEE 802.11x WLAN technology commonly referred to as "Wi-Fi". Exemplary systems of this type include various variants such as CDMA systems, TDMA systems, FDMA systems, orthogonal FDMA (OFDMA) systems, single-carrier FDMA (SC-FDMA) systems, etc.

[0047]

[0058] Figure 1 shows only two of the UEs as SL-UEs (i.e., UE164 and 182), but it should be noted that any of the UEs shown may be an SL-UE. Further, although only UE182 was described as being beamforming capable, any of the UEs shown, including UE164, may be beamforming capable. When the SL-UEs are beamforming capable, they can beamform towards each other (i.e., towards other SL-UEs), towards other UEs (e.g., UE104), towards base stations (e.g., base stations 102, 180, small cell 102', access point 150), etc. Thus, in some cases, UE164 and UE182 may utilize beamforming via sidelink 160.

[0048]

[0059] In the example of Figure 1, any of the UEs shown (shown in Figure 1 as a single UE104 for simplicity) may receive signals 124 from one or more earth-orbiting space vehicles (SVs) 112 (e.g., satellites). In one aspect, SV112 may be part of a satellite positioning system that UE104 can use as an independent source of location information. A satellite positioning system is typically arranged to enable a receiver (e.g., UE104) to determine its location on or above the earth, at least in part based on positioning signals received from a transmitter (e.g., signal 124), and includes a system of transmitters (e.g., SV112). Such transmitters typically transmit signals marked with a set number of repetitions of a pseudo-random noise (PN) code. Although usually located within SV112, the transmitter may sometimes be located on a ground-based control station, base station 102, and / or another UE104. UE104 may include one or more dedicated receivers specifically designed to receive signals 124 for deriving geolocation information from SV112.

[0049]

[0060] In a satellite positioning system, the use of signal 124 may be associated with use involving one or more global and / or regional navigation satellite systems, or may be enabled in another way for such use and may be augmented by various satellite-based augmentation systems (SBAS). For example, SBAS may include augmentation system(s) (singular or plural) that provide integrity information, error correction, etc., such as Wide Area Augmentation System (WAAS), European Geostationary Navigation Overlay Service (EGNOS), Multi-functional Satellite Augmentation System (MSAS), Global Positioning System (GPS)-aided Geo Augmented Navigation, or GPS and Geo Augmented Navigation system (GAGAN). Accordingly, the satellite positioning system as used herein may include any combination of one or more global and / or regional navigation satellites associated with such one or more satellite positioning systems.

[0050]

[0061] In one aspect, SV112 can be part of one or more non-terrestrial networks (NTNs) additionally or alternatively. In an NTN, SV112 is connected to an earth station (also called a ground station, NTN gateway, or gateway), and the earth station is then connected to an element in the 5G network, such as a modified base station 102 (without a terrestrial antenna) or a network node in the 5GC. This element then provides access to other elements in the 5G network and ultimately to entities external to the 5G network, such as Internet web servers and other user devices. In this way, UE104 can receive communication signals (e.g., signal 124) from SV112 instead of or in addition to communication signals from the terrestrial base station 102.

[0051]

[0062] The wireless communication system 100 may further include one or more UEs, such as UE190, that are indirectly connected to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links (referred to as "side links"). In the example of FIG. 1, UE190 has a D2D P2P link 192 with one of the UEs 104 connected to one of the base stations 102 (e.g., through which UE190 may indirectly obtain a cellular connection), and a D2D P2P link 194 with a WLAN STA152 connected to a WLAN AP150 (e.g., through which UE190 may indirectly obtain a WLAN-based Internet connection). In one example, D2D P2P links 192 and 194 can be supported using any well-known D2D RAT, such as LTE Direct (LTE-D), WiFi Direct (WiFi-D), Bluetooth®.

[0052]

[0063] Figure 2A shows an exemplary wireless network configuration 200. For example, 5GC 210 (also referred to as Next Generation Core (NGC)) can be functionally regarded as a control plane (C-plane) function 214 (e.g., UE registration, authentication, network access, gateway selection, etc.) and a user plane (U-plane) function 212 (e.g., UE gateway function, access to data network, IP routing, etc.) that operate collaboratively to form a core network. A user plane interface (NG-U) 213 and a control plane interface (NG-C) 215 connect gNB 222 to 5GC 210, specifically to the user plane function 212 and the control plane function 214, respectively. In an additional configuration, ng-eNB 224 may also be connected to 5GC 210 via NG-C 215 to the control plane function 214 and NG-U 213 to the user plane function 212. Further, ng-eNB 224 may communicate directly with gNB 222 via a backhaul connection 223. In some configurations, Next Generation RAN (NG-RAN) 220 may have one or more gNBs 222, while other configurations include one or more of either ng-eNB 224 and gNB 222. Either gNB 222 or ng-eNB 224 (or both) may communicate with one or more UEs 204 (e.g., any of the UEs described herein).

[0053]

[0064] Another optional aspect may include a location server 230 that may be communicating with the 5GC 210 to provide location assistance to the UE(s) 204. The location server 230 may be implemented as a plurality of distinct servers (e.g., physically distinct 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 UE 204 that can connect to the location server 230 via the core network, via the 5GC 210, and / or via the Internet (not shown). Further, the location server 230 may be integrated within components of the core network or, alternatively, may be external to the core network (e.g., a third-party server such as an original equipment manufacturer (OEM) server or a service server).

[0054]

[0065] Figure 2B shows another exemplary wireless network structure 250. 5GC 260 (which may correspond to 5GC 210 in FIG. 2A) can be considered to functionally include a control plane function provided by an access and mobility management function (AMF) 264 that operates cooperatively to form a core network (i.e., 5GC 260), and a user plane function provided by a user plane function (UPF) 262. The functions of 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, a transparent proxy service for routing SM messages, access authentication and authorization, transport for short message service (SMS) messages between UE 204 and a short message service function (SMSF) (not shown), and security anchor functionality (SEAF). AMF 264 also interacts with an authentication server function (AUSF) (not shown) and UE 204 and receives an intermediate key established as a result of the UE 204 authentication process. In the case of authentication based on a UMTS (Universal Mobile Telecommunications System) subscriber identity module (USIM), AMF 264 retrieves security material from the AUSF. The functions of AMF 264 also include security context management (SCM). SCM receives from SEAF a key that SCM uses to derive an access network specific key.The functionality of the AMF264 also includes location service management for regulatory services, transport of location service messages between the UE204 and the Location Management Function (LMF) 270 acting as the location server 230, transport of location service messages between the NG-RAN 220 and the LMF 270, EPS bearer identifier allocation for interacting with the evolved packet system (EPS), and UE204 mobility event notification. In addition, the AMF264 also supports functions for non-3GPP (Third Generation Partnership Project) access networks.

[0055]

[0066] The functions of the UPF262 include acting as an anchor point for RAT-in / RAT-inter mobility (when applicable), acting as an external protocol data unit (PDU) session point of interconnection to a data network (not shown), performing packet routing and forwarding, packet inspection, user plane policy rule enforcement (e.g., gating, redirection, traffic steering), lawful interception (user plane collection), traffic usage reporting, quality of service (QoS) handling for the user plane (e.g., uplink / downlink rate enforcement, reflective QoS marking in the downlink), uplink traffic verification (mapping from service data flow (SDF) to QoS flow), 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 UPF262 may also support the transfer of location service messages on the user plane between the UE204 and a location server such as the SLP272.

[0056]

[0067] The functions of the SMF266 include session management, UE Internet protocol (IP) address allocation and management, selection and control of user plane functions, configuration of traffic steering in the UPF262 for routing traffic to appropriate destinations, some control of policy enforcement and QoS, and downlink data notification. The interface through which the SMF266 communicates with the AMF264 is called the N11 interface.

[0057]

[0068] Another optional aspect may include an LMF270 that may communicate with the 5GC260 to provide location assistance to the UE204. The LMF270 may be implemented as a plurality of distinct servers (e.g., physically distinct 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 LMF270 may be configured to support one or more location services for the UE204 that can be connected to the LMF270 via the core network, the 5GC260, and / or the Internet (not shown). The SLP272 may support functions similar to those of the LMF270, while on the other hand, the LMF270 may communicate with the AMF264, the NG-RAN220, and the UE204 via the control plane (e.g., using interfaces and protocols intended to transmit signaling messages rather than voice or data), and the SLP272 may communicate with the UE204 and an external client (e.g., a third-party server 274) via the user plane (e.g., using protocols intended to carry voice and / or data such as the Transmission Control Protocol (TCP) and / or IP).

[0058]

[0069] Another optional aspect may include communicating with the LMF 270, SLP 272, 5GC 260 (e.g., via the AMF 264 and / or UPF 262), the NG-RAN 220, and / or a third-party server 274 that may be communicating with the UE 204 to obtain location information (e.g., a location estimate) for the UE 204. Thus, in some cases, the third-party server 274 may be referred to as a location service (LCS) client or an external client. The third-party server 274 may be implemented as a plurality of distinct servers (e.g., physically distinct servers, different software modules on a single server, different software modules spread across multiple physical servers, etc.), or alternatively, each may correspond to a single server.

[0059]

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

[0060]

[0071] The functionality of gNB 222 can be split between a gNB central unit (gNB-CU) 226, one or more gNB distributed units (gNB-DUs) 228, and one or more gNB radio units (gNB-RUs) 229. The gNB-CU 226 is a logical node that includes base station functions such as transferring user data, mobility control, radio access network sharing, positioning, session management, etc., except for those functions that are exclusively allocated to the gNB-DU(s) 228. More specifically, the gNB-CU 226 generally hosts the radio resource control (RRC), service data adaptation protocol (SDAP), and packet data convergence protocol (PDCP) protocols of gNB 222. The gNB-DU 228 is a logical node that generally hosts the radio link control (RLC) and media access control (MAC) layers of gNB 222. Its operation is controlled by the gNB-CU 226. One gNB-DU 228 can support one or more cells, and one cell is supported by only one gNB-DU 228. The interface 232 between the gNB-CU 226 and one or more gNB-DUs 228 is called the "F1" interface. The physical (PHY) layer functionality of gNB 222 is generally hosted by one or more stand-alone gNB-RUs 229 that perform functions such as power amplification and signal transmission / reception. The interface between the gNB-DU 228 and the gNB-RU 229 is called the "Fx" interface. Thus, the UE 204 communicates with the gNB-CU 226 via the RRC, SDAP, and PDCP layers, with the gNB-DU 228 via the RLC and MAC layers, and with the gNB-RU 229 via the PHY layer.

[0061]

[0072] Figures 3A, 3B, and 3C show some exemplary components (represented by corresponding blocks) that may be incorporated within a User Equipment (UE) 302 (which may correspond to any of the UEs described herein), a base station 304 (which may correspond to any of the base stations described herein), and a network entity 306 (which may correspond to or embody any of the network functions described herein, including location server 230 and LMF 270, or alternatively, may be independent of the NG-RAN 220 and / or 5GC 210 / 260 infrastructure shown in FIGS. 2A and 2B, such as a private network) to support the operations described herein. It will be understood that these components may be implemented in different types of devices in different implementation forms (e.g., within an ASIC, within a system-on-chip (SoC), etc.). The components shown may also be incorporated within other devices in the communication system. For example, other devices in the system may include components similar to those described 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.

[0062]

[0073] UE 302 and base station 304 each include one or more Wireless Wide Area Network (WWAN) transceivers 310 and 350, and provide means (e.g., means for transmitting, means for receiving, means for measuring, means for synchronizing, means for refraining from transmitting, etc.) for communicating via one or more wireless communication networks (not shown), such as an NR network, an LTE network, a GSM network, etc. WWAN transceivers 310 and 350 can 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., eNB, gNB), etc. via at least one designated Radio Access Technology (RAT) (e.g., NR, LTE, GSM, etc.) on a target wireless communication medium (e.g., some set of time / frequency resources in a specific frequency spectrum). WWAN transceivers 310 and 350 can be variously configured to transmit and encode signals 318 and 358 (e.g., messages, instructions, information, etc.) and, conversely, to receive and decode signals 318 and 358 (e.g., messages, instructions, information, pilots, etc.) according to the designated RAT. Specifically, WWAN transceivers 310 and 350 each include one or more transmitters 314 and 354, respectively, for transmitting and encoding signals 318 and 358, and each include one or more receivers 312 and 352, respectively, for receiving and decoding signals 318 and 358.

[0063]

[0074] UE 302 and base station 304 also each include, in at least some cases, one or more short-range wireless transceivers 320 and 360, respectively. Short-range wireless transceivers 320 and 360 may each be connected to one or more antennas 326 and 366, respectively, and provide means (e.g., means for transmitting, means for receiving, means for measuring, means for synchronizing, means for refraining from transmitting, etc.) for communicating with other network nodes such as other UEs, access points, base stations, etc. via the wireless communication medium over 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.). Short-range wireless transceivers 320 and 360 may be variously configured to transmit and encode signals 328 and 368 (e.g., messages, instructions, information, etc.) and, conversely, to receive and decode signals 328 and 368 (e.g., messages, instructions, information, pilots, etc.) according to the designated RAT. Specifically, short-range wireless transceivers 320 and 360 each include one or more transmitters 324 and 364, respectively, for transmitting and encoding signals 328 and 368, and each include one or more receivers 322 and 362, respectively, for receiving and decoding signals 328 and 368. As a specific example, 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.

[0064]

[0075] UE 302 and base station 304 also include satellite signal receivers 330 and 370 in at least some cases. Satellite signal receivers 330 and 370 can be connected to one or more antennas 336 and 376 respectively, and can each provide means for receiving and / or measuring satellite positioning / communication signals 338 and 378. When satellite signal receivers 330 and 370 are satellite positioning system receivers, satellite positioning / communication signals 338 and 378 can be Global Positioning System (GPS) signals, Global Navigation Satellite System (GLONASS) signals, Galileo signals, Beidou signals, Indian Regional Navigation Satellite System (NAVIC), Quasi-Zenith Satellite System (QZSS), etc. When satellite signal receivers 330 and 370 are non-terrestrial network (NTN) receivers, satellite positioning / communication signals 338 and 378 can be communication signals transmitted from a 5G network (e.g., carrying control and / or user data). Satellite signal receivers 330 and 370 can each include any suitable hardware and / or software for receiving and processing satellite positioning / communication signals 338 and 378. Satellite signal receivers 330 and 370 can appropriately request information and operations from other systems, and in at least some cases, perform calculations using the obtained measurements to determine the locations of UE 302 and base station 304 respectively by any suitable satellite positioning system algorithm.

[0065]

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

[0066]

[0077] The transceiver may be configured to communicate via a wired link or a wireless link. (Regardless of whether it is a wired transceiver or a wireless transceiver), the transceiver includes a transmitter circuit configuration (e.g., transmitters 314, 324, 354, 364) and a receiver circuit configuration (e.g., receivers 312, 322, 352, 362). In some implementations, the transceiver may be an integrated device (e.g., embodying the transmitter circuit configuration and the receiver circuit configuration within a single device), in some implementations, it may comprise separate transmitter and receiver circuit configurations, or in other implementations, it may be embodied in other ways. The transmitter and receiver circuit configurations 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 circuit configurations (e.g., transmitters 314, 324, 354, 364) may include, or be coupled to, a plurality of antennas (e.g., antennas 316, 326, 356, 366), such as an antenna array that enables each device (e.g., UE 302, base station 304) to perform transmission “beamforming” as described herein. Similarly, the wireless receiver circuit configurations (e.g., receivers 312, 322, 352, 362) may include, or be coupled to, a plurality of antennas (e.g., antennas 316, 326, 356, 366), such as an antenna array that enables each device (e.g., UE 302, base station 304) to perform receive beamforming as described herein. In one aspect, the transmitter and receiver circuit configurations may share a plurality of the same antennas (e.g., antennas 316, 326, 356, 366) such that each device can only receive or transmit at a given time and not both at the same time. The wireless transceivers (e.g., WWAN transceivers 310 and 350, short-range wireless transceivers 320 and 360) may also include, for example, a network listen module (NLM) for performing various measurements.

[0067]

[0078] 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) used in this specification may generally be characterized as a "transceiver", "at least one transceiver", or "one or more transceivers". Thus, whether a particular transceiver is a wired transceiver or a wireless transceiver can be inferred from the type of communication being implemented. For example, backhaul communication between network devices or servers generally involves signaling via a wired transceiver, while wireless communication between a UE (e.g., UE 302) and a base station (e.g., base station 304) generally involves signaling via a wireless transceiver.

[0068]

[0079] UE 302, base station 304, and network entity 306 may also include other components that can be used in conjunction with the operations as disclosed in this specification. UE 302, base station 304, and network entity 306 each include one or more processors 332, 384, and 394, for example, to provide functions related to wireless communication and to provide other processing functions. Thus, processors 332, 384, and 394 can be equipped with processing means such as means for determining, means for calculating, means for receiving, means for transmitting, means for instructing, etc. In one aspect, processors 332, 384, and 394 can 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.

[0069]

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

[0070]

[0081] The UE 302 can include one or more sensors 344 coupled to one or more processors 332 to provide means for detecting or sensing movement and / or orientation information that is independent of movement data derived from signals received by one or more WWAN transceivers 310, one or more short-range wireless transceivers 320, and / or a satellite signal receiver 330. By way of example, the sensor(s) 344 can include an accelerometer (e.g., a micro-electrical mechanical systems (MEMS) device), a gyroscope, a geomagnetic sensor (e.g., a compass), an altimeter (e.g., a barometric altimeter), and / or any other type of movement detection sensor. Further, the sensor(s) 344 can include multiple different types of devices and can combine their outputs to provide movement information. For example, the sensor(s) 344 can 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.

[0071]

[0082] In addition, the UE 302 includes a user interface 346 that provides means for providing an indication (e.g., an acoustic and / or visual display) to the user and / or for receiving user input (e.g., when the user operates a sensing device such as a keypad, a touch screen, a microphone, etc.). Although not shown, the base station 304 and the network entity 306 may also include a user interface.

[0072]

[0083] Looking more specifically at one or more processors 384, in the downlink, IP packets from network entity 306 may be provided to processor 384. The one or more processors 384 may implement functions for the RRC layer, the packet data convergence protocol (PDCP) layer, the radio link control (RLC) layer, and the media access control (MAC) layer. The one or more processors 384 may include RRC layer functions associated with the 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 associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functions associated with the transfer of upper layer PDUs, error correction by automatic repeat request (ARQ), concatenation, segmentation, and reassembly of RLC service data units (SDUs), resegmentation of RLC data PDUs, and rearrangement of RLC data PDUs; and MAC layer functions associated with the mapping between logical channels and transport channels, scheduling information reporting, error correction, priority handling, and logical channel prioritization.

[0073]

[0084] Transmitter 354 and receiver 352 may implement Layer-1 (L1) functions associated with various signal processing functions. Layer 1, including the Physical (PHY) layer, may include error detection on the transport channel, forward error correction (FEC) coding / decoding of the transport channel, interleaving, rate matching, mapping onto the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. 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-quadrature amplitude modulation (M-QAM)). The encoded and modulated symbols may then be split into parallel streams. Each stream is then mapped to orthogonal frequency division multiplexing (OFDM) subcarriers, multiplexed with a reference signal (e.g., pilot) in the time and / or frequency domain, and then synthesized together using an inverse fast Fourier transform (IFFT) to generate a physical channel carrying a time-domain OFDM symbol stream. The OFDM symbol stream is spatially precoded to generate multiple spatial streams. Channel estimates from the channel estimator may be used to determine the coding and modulation scheme and for spatial processing. The channel estimates may be derived from reference signals transmitted by UE 302 and / or channel state feedback. Each spatial stream may then be provided to one or more different antennas 356. Transmitter 354 may modulate an RF carrier using individual spatial streams for transmission.

[0074]

[0085] In UE302, receiver 312 receives signals through its respective antenna(s) 316. Receiver 312 recovers the information modulated on the RF carrier and provides the information to one or more processors 332. Transmitter 314 and receiver 312 implement layer 1 functions associated with various signal processing functions. Receiver 312 may perform spatial processing on the information to recover any spatial stream directed to UE302. If multiple spatial streams are directed to UE302, they may be combined by receiver 312 into a single OFDM symbol stream. Receiver 312 then uses a fast Fourier transform (FFT) to convert the OFDM symbol stream from the time domain to the frequency domain. The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signals, are recovered and demodulated by determining the most likely signal constellation points transmitted by base station 304. These soft decisions may be based on the channel estimates calculated by the channel estimator. The soft decisions are then decoded and deinterleaved to recover the data signals and control signals originally transmitted by base station 304 on the physical channel. The data and control signals are then provided to one or more processors 332 that implement layer 3 (L3) and layer 2 (L2) functions.

[0075]

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

[0076]

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

[0077]

[0088] Channel estimation values derived by a channel estimator from a reference signal or feedback transmitted by the base station 304 can 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 can be provided to different antennas (s). The transmitter 314 can modulate an RF carrier using individual spatial streams for transmission.

[0078]

[0089] Uplink transmission is processed at the base station 304 in a manner similar to the method described for the receiver function in the UE 302. The receiver 352 receives signals via its respective antenna(s) 356. The receiver 352 recovers the information modulated on the RF carrier and provides the information to one or more processors 384.

[0079]

[0090] On the uplink, one or more processors 384 provide demultiplexing in reverse between the transport channel and the logical channel, packet reassembly, decoding, header restoration, and control signal processing to restore IP packets from the UE 302. The IP packets from one or more processors 384 can be provided to the core network. One or more processors 384 are also responsible for error detection.

[0080]

[0091] For convenience, the UE 302, the base station 304, and / or the network entity 306 are shown in FIGS. 3A, 3B, and 3C as including various components that can be configured according to the various examples described herein. However, it should be understood that the components shown may have different functions in different designs. Specifically, the various components in FIGS. 3A-3C are optional in alternative configurations, and the various aspects include configurations that may vary due to design choices, cost, device usage, or other considerations. For example, in the case of FIG. 3A, a particular implementation of the UE 302 may omit the WWAN transceiver(s) 310 (e.g., a wearable device or a tablet computer or a PC or a laptop may have Wi-Fi and / or Bluetooth capabilities without cellular capabilities), or may omit the short-range wireless transceiver(s) 320 (e.g., cellular only), or may omit the satellite signal receiver 330, or may omit the sensor(s) 344, etc. In another example, in the case of FIG. 3B, a particular implementation of the base station 304 may omit the WWAN transceiver(s) 350 (e.g., a Wi-Fi "hotspot" access point without cellular capabilities), or may omit the short-range wireless transceiver(s) 360 (e.g., cellular only), or may omit the satellite receiver 370, etc. For the sake of brevity, examples of various alternative configurations are not provided herein, but should be readily understandable to those skilled in the art.

[0081]

[0092] The various components of UE302, base station 304, and network entity 306 can be communicatively coupled to each other via data buses 334, 382, and 392, respectively. In one aspect, data buses 334, 382, and 392 can form, or be part of, the communication interfaces of UE302, base station 304, and network entity 306, respectively. For example, if different logical entities are implemented within the same device (e.g., a gNB and a location server functionality incorporated within the same base station 304), data buses 334, 382, and 392 can provide communication between them.

[0082]

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

[0083]

[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., NG RAN 220 and / or 5GC 210 / 260). For example, the network entity 306 may be a component of a private network that is configured to communicate with the UE 302 via the base station 304 or independently from the base station 304 (e.g., via a non-cellular communication link such as WiFi).

[0084]

[0095] Wireless communication signals transmitted between the UE and the base station (e.g., RF signals configured to carry OFDM symbols) can be reused for environmental sensing (also referred to as "RF sensing" or "radar"). Using wireless communication signals for environmental sensing can be regarded as a consumer-level radar with advanced detection capabilities that enables, among other things, touchless / device-free interaction with devices / systems. The wireless communication signal may be a cellular communication signal such as an LTE or NR signal, a WLAN signal, etc. As a specific example, the wireless communication signal may be an OFDM waveform as utilized in LTE and NR. High-frequency communication signals such as mmW RF signals are particularly beneficial to use as radar signals because higher frequencies at least provide more accurate range (distance) detection.

[0085]

[0096] Figures 4A and 4B show two of these various types of radars. Generally, there are different types of radars, particularly monostatic radars and bistatic radars. Specifically, FIG. 4A is a diagram 400 showing a monostatic radar scenario, and FIG. 4B is a diagram 410 showing a bistatic radar scenario.

[0086]

[0097] In FIG. 4A, the base station 402 may be configured for full-duplex operation, and thus, the transmitter (Tx) and the receiver (Rx) are at the same location. For example, the transmitted radio signal 406 may be reflected from a target object such as a building 404, and the receiver on the base station 402 is configured to receive and measure the reflected beam 408. This is a typical use case of traditional or conventional radar.

[0087]

[0098] In FIG. 4B, the base station 412 may be configured as a transmitter (Tx), and the UE 414 may be configured as a receiver (Rx). In this example, the transmitter and the receiver are not at the same location. That is, they are separated by a distance comparable to, for example, the expected target distance. The base station 412 may be configured to transmit a beam such as an omnidirectional downlink RF signal 406 that can be received by the UE 414. A portion of the RF signal 406 may be reflected or refracted by the building 404, and the UE 414 may receive this reflected signal 416. This is a typical use case of RF sensing based on wireless communication (e.g., WiFi-based, LTE-based, NR-based). Note that FIG. 4B shows the use of the downlink RF signal 406 as an RF sensing signal, but it should be noted that the uplink RF signal can also be used as an RF sensing signal. In the downlink scenario, as shown, the transmitter is the base station 412 and the receiver is the UE 414, while in the uplink scenario, the transmitter is the UE and the receiver is the base station. A multistatic radar system is a generalization of a bistatic radar system that includes at least three components, e.g., one receiver and two transmitters, two receivers and one transmitter, or multiple receivers and multiple transmitters.

[0088]

[0099] Referring to FIG. 4B in more detail, the base station 412 transmits an RF sensing signal (e.g., PRS) to the UE 414, and some of the RF sensing signals are reflected by a target object such as the building 404. The UE 414 can measure the ToA of the RF signal 406 directly received from the base station and the ToA of the reflected signal 416 reflected from the target object (e.g., the building 404).

[0089]

[0100] The base station 412 may be configured to transmit a single RF signal 406 or a plurality of RF signals to a receiver (e.g., the UE 414). However, due to the propagation characteristics of the RF signal through the multipath channel, the UE 414 may receive a plurality of RF signals corresponding to each transmitted RF signal. Each path may be associated with a cluster of one or more channel taps. Generally, the time when the receiver detects the first cluster of channel taps is regarded as the ToA of the RF signal on the line-of-site (LOS) path (i.e., the shortest path between the transmitter and the receiver). The subsequent clusters of channel taps are considered to follow a non-LOS (NLOS) path between the transmitter and the receiver that is reflected by an object between the transmitter and the receiver.

[0090]

[0101] Therefore, referring to FIG. 4B again, the RF signal 406 follows the LOS path between the base station 412 and the UE 414, and the reflected signal 416 represents an RF detection signal that follows the NLOS path between the base station 412 and the UE 414 due to reflection from the building 404 (or another target object). The base station 412 may have transmitted a plurality of RF sensing signals (not shown in FIG. 4B), some of which follow the LOS path and others follow the NLOS path. Alternatively, the base station 412 may have transmitted a single RF detection signal in a beam wide enough for a portion of the RF sensing signal to follow the LOS path and a portion of the RF sensing signal to follow the NLOS path.

[0091]

[0102] Based on the difference between the ToA of the LOS path and the ToA of the NLOS path, and the speed of light, the UE 414 can determine the distance to the building 404. Additionally, if the UE 414 is capable of performing receive beamforming, the UE 414 may be able to determine the general direction to the building 404 as the direction of the reflected signal 416, which is an RF detection signal that follows the NLOS path when received. The UE 414 may then optionally report this information to the transmitting base station 412, an application server associated with the core network, an external client, a third - party application, or some other entity. Alternatively, the UE 414 may report the ToA measurement results to the base station 412 or other entity, and the base station 412 may determine the distance and, optionally, the direction to the target object.

[0092]

[0103] Note that if the RF detection signal is an uplink RF signal transmitted by the UE 414 to the base station 412, the base station 412 will perform object detection based on the uplink RF signal in much the same way as the UE 414 performs object detection based on the downlink RF signal.

[0093]

[0104] FIG. 5 shows an exemplary distance calculation using a bistatic or multistatic radar. The distance from the transmitter to the target to the receiver, referred to herein as the Tx - target - Rx distance, is measured by a bistatic radar as R SUM =R T +R R The distance R SUM identifies the position of the target on the surface of an ellipsoid whose foci are the radar transmitter side and the radar receiver site. The time interval between the reception of the line - of - sight (LOS) signal transmitted by the transmitter and the reception of the target echo can be used to measure the sum of distances R SUM :

[0094]

Number

[0095]

[0105] Here, L is the baseline distance between the transmitter and the receiver. The target distance from the perspective of the receiver can be calculated as follows:

[0096]

Equation

[0097]

[0106] The angle θ of the angle of arrival (AoA) R can be estimated by the antenna array at the receiver. In the case of a multistatic radar, the angle θ R can be estimated through multi-lateration. In the case of a stationary transmitter and receiver, the target bistatic Doppler frequency is given by the following equation.

[0098]

Equation

[0099]

[0107] The bandwidth (BW) allocated for cellular communication systems (e.g., for 5G and above) is increasing, and more use cases for cellular communication systems are being introduced. Therefore, joint communication and RF sensing (JCS) is a desirable feature for future cellular systems. Since spectrum resources are always scarce, it is desirable for JCS to have high spectral efficiency, and allocating slots or sub-slots for RF sensing is not spectrally efficient from the perspective of communication or JCS. Furthermore, it is desirable to use the same waveform for both communication and sensing, but different requirements for communication and sensing make it difficult to achieve this goal. For example, the beams for communication and the beams for sensing can be very different. Another example is that communication signals may not need high-resolution velocity estimation, while sensing signals may need to support high-resolution velocity estimation.

[0100]

[0108] To overcome the technical problems described above, techniques for opportunistic RF sensing in a cellular system are presented herein. The following techniques achieve high spectral efficiency JCS. These techniques utilize opportunities to transmit and receive sensing reference signals in a manner that does not affect the operation of the UE and, therefore, does not reduce spectral efficiency compared to a baseline cellular system. These techniques include RF sensing during guard periods, RF sensing during BWP switching, and RF sensing during beam switching.

[0101] RF sensing during guard periods

[0109] FIG. 6 is a time and frequency diagram 600 showing an exemplary guard period during which the UE does not transmit any other signals. FIG. 6 shows the last 7 symbols of slot n and the first 2 symbols of the next slot n+1. In NR Rel-15 / 16, the UE can be configured with a maximum of 2 SRS resource sets for antenna switching. In the example shown in FIG. 6, PUSCH 602 occupies symbols 7 and 8 of slot n, the first SRS 604 occupies symbol 10 of slot n, the second SRS 606 occupies symbol 12 of slot n, and the first 2 symbols of slot n+1 are downlink (DL) slots 608. FIG. 6 shows three types of guard periods used when switching to or from SRS and other channels: · When there is a PUSCH transmission from the same UE before the SRS, the guard period 610 before the SRS is used, · Between sets of SRS resources transmitted within the same slot, the guard period 612 is used, which is 2 symbols in length for a 120 kHz subcarrier spacing and 1 symbol otherwise, · For the UL to DL switch, the guard period 614 after the last SRS resource is used.

[0102]

[0110] Since the UE is not expected to transmit UL signals or receive DL signals during these guard periods, these guard periods provide an opportunity for the base station to transmit RF sensing signals. When RF sensing is monostatic and the RF sensing transmitter and receiver are at the base station, the sensing reference signal is then transparent to the UE and the UE is completely unaware of the sensing activity. When RF sensing is bistatic or multistatic, the serving base station may need to notify the non-serving base station of the time and frequency information of the guard period, which may be done through X2 signaling between the base stations. The serving and non-serving base stations can each be either the sensing transmitter or the sensing receiver. In some aspects, the serving base station may send auxiliary data to a radar server, which then allocates opportunistic sensing reference signal transmission and reception for a group of base stations, e.g., both the serving and non-serving base stations.

[0103] RF Sensing During BWP Switching

[0111] FIG. 7 is a time and frequency diagram 700 showing an exemplary BWP switching period during which the UE does not transmit any other signals. In FIG. 7, the UE is switching from a first DL BWP 702 to a second DL BWP 704. The current specification for changing the BWP includes a switching delay 706 defined as the number of slots according to the following table:

[0104]

Table 1

[0105] This switching delay results in a reduction in spectral efficiency.

[0106]

[0112] In some aspects of the present disclosure, the UE may be configured with multiple BWPs (the current standard supports a maximum of 4 DL / UL BWPs in the downlink), and BWP switching may be achieved through the following: ·PDCCH (i.e., DCI): A specific BWP can be activated by the BWP indicator in DCI format 0_1 (UL grant) and DCI format 1_1 (DL schedule). · A BWP inactivity timer, such as ServingCellConfig.bwp-InactivityTimer · RRC signaling · The MAC entity itself at the start of the RACH procedure

[0107]

[0113] Therefore, the serving base station will be aware when the UE performs BWP switching. In some aspects, the base station can transmit or receive an RF sensing signal during the BWP switching of one UE or a group of UEs. The RF sensing signal is transparent to the UE, and the UE is completely unaware of the sensing activity. If the RF sensing is bistatic or multistatic, the serving base station may need to notify the non-serving base station of the BWP switching time and frequency information, which can be done through X2 signaling between base stations. The serving and non-serving base stations can each be a sensing transmitter or a sensing receiver. In some aspects, the serving base station can send auxiliary data to a radar server, which then assigns opportunistic sensing reference signal transmission and reception for a group of base stations, e.g., both the serving and non-serving base stations.

[0108] RF Sensing During Beam Switching

[0114] Figure 8 shows an example 800 of beam switching by base station 412 and UE 414 where the UE does not transmit any other signals. In the example shown in Figure 8, base station 412 and UE 414 are in the presence of a reflecting object, such as building 404. Base station 412, such as a 5G NR gNB, is configured to transmit multiple beamformed signals, such as the first transmit beam 802 and the second transmit beam 804 in Figure 8, along different azimuth angles, elevation angles, and / or beam widths. For example, the beams transmitted by base station 412 may be based on SS blocks, CSI-RS, TRS, or PRS resource sets. Other detection reference signals and tracking reference signals may also be used. UE 414 is configured to utilize receive beamforming to improve the gain of the signals based on the angle of arrival. UE 414 may be configured to utilize phase shifters and other software and hardware techniques to generate receive beams, such as the first receive beam 806 and the second receive beam 808. UE 414 may also be configured to utilize beamforming on the transmitted beams. Base station 412 may transmit a first reference signal 810 that can be reflected in the direction of a target object, such as building 404, on the first transmit beam 802, and UE 414 may receive the reflected signal 812 using the first receive beam 806. The reflected signal 812 represents the NLOS path of the first reference signal 810 to UE 414. Base station 412 also transmits a second reference signal 814 on the second beam 804. In one example, the second reference signal 814 may be quasi-co-located (QCL) with the first reference signal 810. UE 414 receives the second reference signal 814 using the second receive beam 808. The second reference signal 814 is the LOS path to UE 414. In the example shown in Figure 8, UE 414 must change its phase shifters and other hardware or software in order to change its receive beam, for example, from the first receive beam 806 to the second receive beam 808. During this change, UE 414 does not transmit any signals. This provides yet another opportunity for the base station to perform RF sensing.

[0109]

[0115] Therefore, in some aspects, when one UE or a group of UEs performs beam switching, the base station transmits and / or receives RF sensing signals during the beam switching gap. In some aspects, the beam switching gap is defined by a table within the specification for the UE beam switching gap, in which case the UE may indicate the index of the switching duration being used. In some aspects, the UE may notify the expected or maximum switching duration for a particular switch, and in some aspects, the UE may notify the scheduled time or instance for beam switching by specifying, for example, a system frame number (SFN), a slot index, a symbol index, etc. The RF sensing signal is transparent to the UE, and the UE is completely unaware of the sensing activity. If the RF sensing is bistatic or multistatic, the serving base station may need to notify the non-serving base station of the time and frequency information of the beam switching gap, which may be done through X2 signaling between base stations. The serving and non-serving base stations can each be either a sensing transmitter or a sensing receiver. In some aspects, the serving base station may send auxiliary data to a radar server, which then allocates opportunistic sensing reference signal transmission and reception for a group of base stations, e.g., both the serving and non-serving base stations.

[0110]

[0116] FIG. 9 is a flowchart of an exemplary process 900 associated with opportunistic RF sensing in a cellular system. In some implementations, one or more process blocks of FIG. 9 may be performed by a network entity, such as a base station (BS) (e.g., BS102, gNB, etc.). In some implementations, one or more process blocks of FIG. 9 may be performed by another device or group of devices separate from or including the network entity. In addition or alternatively, one or more process blocks of FIG. 9 may be implemented by one or more components of BS304, such as processor(s) 384, memory 386, WWAN transceiver(s) 350, short-range wireless transceiver(s) 360, satellite signal receiver 370, network transceiver(s) 380, and RF sensing component(s) 388, any or all of which may be means for performing the operations of process 900.

[0111]

[0117] As shown in FIG. 9, process 900 may include identifying an opportunity for radio frequency (RF) sensing in which a user equipment (UE) is not transmitting a signal, the opportunity including an opportunity that includes a guard period of the UE, a bandwidth part (BWP) switching period of the UE, or a beam switching period of the UE (block 910). Means for performing the operation of block 910 may include processor(s) 384, memory 386, or WWAN transceiver(s) 350 of BS304. For example, BS304 may use processor(s) 384 to identify an opportunity for RF sensing.

[0112]

[0118] In some aspects, identifying an opportunity for RF sensing includes identifying a guard period of the UE, where the guard period is associated with sounding reference signals (SRSs) transmitted by the UE. In some aspects, identifying a guard period of the UE includes identifying a guard period used after the UE transmits a physical uplink shared channel (PUSCH) and before the UE transmits an SRS. In some aspects, identifying a guard period of the UE includes identifying a guard period used between SRSs transmitted within the same slot. In some aspects, identifying a guard period of the UE includes identifying a guard period used after the last SRS transmitted within a slot and before the UE switches from uplink transmission to downlink transmission.

[0113]

[0119] In some aspects, identifying an opportunity for RF sensing includes identifying a BWP switching period of the UE. In some aspects, identifying a BWP switching period of the UE includes identifying a switching delay when the UE switches from a first BWP to a second BWP. In some aspects, identifying a BWP switching period of the UE includes identifying the BWP switching period based on at least one of a BWP indicator in a downlink control information (DCI) message to the UE, a BWP inactivity timer associated with the UE, radio resource control (RRC) signaling related to the UE, or a media access control (MAC) entity at the start of a random access (RACH) procedure.

[0114]

[0120] In some aspects, identifying an opportunity for RF sensing includes identifying a beam switching period of the UE. In some aspects, identifying a beam switching period of the UE includes receiving an indication of the beam switching period from the UE. In some aspects, receiving an indication of the beam switching period from the UE includes receiving a beam switching gap location identified by a system frame number (SFN), slot index, symbol index, switching duration, or a combination thereof. In some aspects, receiving a beam switching gap location includes receiving an index to a predefined table of beam switching gap locations, a maximum switching duration for a particular beam switching gap location, or a combination thereof.

[0115]

[0121] As further shown in FIG. 9, process 900 may include transmitting an RF sensing signal, receiving an RF sensing signal, or both, during an opportunity for RF sensing (block 920). Means for performing the operations of block 920 may include the processor(s) 384, memory 386, or WWAN transceiver(s) 350 of BS 304. For example, BS 304 may transmit an RF sensing signal using transmitter(s) 354 and receive an RF sensing signal using receiver(s) 352.

[0116]

[0122] Process 900 may include additional implementations, such as any single implementation, or any combination of implementations, described herein below and / or with respect to one or more other processes described elsewhere in this specification. Although FIG. 9 shows exemplary blocks of process 900, in some implementations, process 900 may include additional blocks, fewer blocks, different blocks, or differently configured blocks than those shown in FIG. 9. Additionally or alternatively, two or more of the blocks of process 900 may be executed in parallel.

[0117]

[0123] FIG. 10 is a flowchart of an exemplary process 1000 associated with opportunistic RF sensing in a cellular system. In some implementations, one or more process blocks of FIG. 10 may be performed by a user equipment (UE) (e.g., UE 104). In some implementations, one or more process blocks of FIG. 10 may be performed by another device, or a group of devices that are separate from or include the UE. In addition or alternatively, one or more process blocks of FIG. 10 may be performed by one or more components of the UE 302, such as processor(s) 332, memory 340, WWAN transceiver(s) 310, short-range wireless transceiver(s) 320, satellite signal receiver 330, sensor(s) 344, user interface 346, and RF sensing component(s) 342, any or all of which may be means for performing the operations of process 1000.

[0118]

[0124] As shown in FIG. 10, process 1000 may include determining an opportunity for a network entity, such as a base station, to perform RF sensing while the UE is not transmitting a signal, where the opportunity includes a guard period of the UE, a BWP switching period of the UE, or a beam switching period of the UE (block 1010). The means for performing the operation of block 1010 may include processor(s) 332, memory 340, or WWAN transceiver(s) 310 of the UE 302. For example, the UE 302 may use processor(s) 332 to determine an opportunity for a network entity to perform RF sensing.

[0119]

[0125] As further shown in FIG. 10, process 1000 may include instructing a network entity of an opportunity for RF sensing (block 1020). Means for performing the operation of block 1020 may include processor(s) 332, memory 340, or WWAN transceiver(s) 310 of UE 302. For example, UE 302 may send an instruction using transmitter(s) 314.

[0120]

[0126] In some aspects, instructing an opportunity for RF sensing includes instructing a BWP switching period of a UE. In some aspects, instructing a BWP switching period of a UE includes instructing a switching delay for the UE to switch from a first BWP to a second BWP. In some aspects, instructing a BWP switching period of a UE includes instructing a BWP switching period based on at least one of radio resource control (RRC) signaling related to the UE or a media access control (MAC) entity at the start of a random access (RACH) procedure.

[0121]

[0127] In some aspects, instructing an opportunity for RF sensing includes instructing a beam switching period of a UE. In some aspects, instructing a beam switching period of a UE includes sending an instruction of the beam switching period. In some aspects, sending an instruction of the beam switching period includes sending a beam switching gap location identified by a system frame number (SFN), a slot index, a symbol index, a switching duration, or a combination thereof. In some aspects, sending a beam switching gap location includes sending an index to a predefined table of beam switching gap locations, a maximum switching duration for a particular beam switching gap location, or a combination thereof.

[0122]

[0128] Process 1000 may include additional implementation forms, such as any single implementation form, or any combination of implementation forms, described with respect to one or more other processes described below and / or elsewhere in this specification. Although FIG. 10 shows exemplary blocks of process 1000, in some implementations, process 1000 may include additional blocks, fewer blocks, different blocks, or differently configured blocks than those shown in FIG. 10. Additionally or alternatively, two or more of the blocks of process 1000 may be executed in parallel.

[0123]

[0129] As will be appreciated, the technical advantage of the method described herein is that by utilizing existing periods that the UE is not already transmitting or receiving, the base station can opportunistically perform RF sensing in a manner that does not require any change in the UE's behavior and thus does not adversely affect spectral efficiency.

[0124]

[0130] In the following embodiments for carrying out the above invention, it can be seen that in each example, various features are grouped together. This manner of disclosure should not be understood as an intention that exemplary clauses have more features than are explicitly stated within each clause. Rather, various aspects of the present disclosure may include fewer features than all of the features of the individual exemplary clauses being disclosed. Accordingly, the following clauses should be considered as incorporated into the description, and each clause may be valid separately as a distinct example. Each dependent clause may refer within that clause to a particular combination with one of the other clauses, but the aspect(s) of that dependent clause is / are not limited to that particular combination. It will be understood that other exemplary clauses may also include combinations of aspect(s) of dependent clauses with the subject matter of any other dependent or independent clause, or any combination of features with other dependent and independent clauses. The various aspects disclosed herein do not explicitly include these combinations unless it is explicitly stated or can be readily inferred that a particular combination (such as defining an element as both an electrical insulator and an electrical conductor, etc., conflicting aspects) is not intended. Further, even if a clause is not directly dependent on an independent clause, it is also intended that the aspect of the clause may be included in any other independent clause.

[0125]

[0131] In the following numbered clauses, implementation examples are described.

[0126]

[0132] Clause 1. A method of RF sensing performed by a network entity, the method comprising identifying an opportunity for radio frequency (RF) sensing in which a user equipment (UE) does not transmit a signal, the opportunity including a guard period of the UE, a bandwidth part (BWP) switching period of the UE, or a beam switching period of the UE, and transmitting an RF sensing signal, receiving an RF sensing signal, or both, during the opportunity for RF sensing.

[0127]

[0133] Clause 2. The method according to clause 1, wherein identifying an opportunity for RF sensing includes identifying a guard period of the UE, where the guard period is associated with sounding reference signals (SRSs) transmitted by the UE.

[0128]

[0134] Clause 3. The method according to clause 2, wherein identifying a guard period of the UE includes identifying a guard period used after the transmission of a physical uplink shared channel (PUSCH) by the UE and before the transmission of an SRS by the UE.

[0129]

[0135] Clause 4. The method according to clause 2 or 3, wherein identifying a guard period of the UE includes identifying a guard period used between transmissions of SRSs transmitted within the same slot.

[0130]

[0136] Clause 5. The method according to any one of clauses 2 to 4, wherein identifying a guard period of the UE includes identifying a guard period used after the last SRS transmitted within a slot and before the UE switches from uplink transmission to downlink transmission.

[0131]

[0137] Clause 6. The method according to any one of clauses 1 to 5, wherein identifying an opportunity for RF sensing includes identifying a BWP switching period of the UE.

[0132]

[0138] Clause 7. The method according to clause 6, wherein identifying a BWP switching period of the UE includes identifying a switching delay when the UE switches from a first BWP to a second BWP.

[0133]

[0139] Clause 8. Identifying the BWP switching period of the UE includes identifying the BWP switching period based on at least one of a BWP indicator in a downlink control information (DCI) message to the UE, a BWP inactivity timer associated with the UE, radio resource control (RRC) signaling related to the UE, or a media access control (MAC) entity at the start of a random access (RACH) procedure, the method according to Clause 6 or 7.

[0134]

[0140] Clause 9. Identifying an opportunity for RF sensing includes identifying the beam switching period of the UE, the method according to any one of Clauses 1 to 8.

[0135]

[0141] Clause 10. Identifying the beam switching period of the UE includes receiving an indication of the beam switching period from the UE, the method according to Clause 9.

[0136]

[0142] Clause 11. Receiving an indication of the beam switching period from the UE includes receiving a beam switching gap location identified by a system frame number (SFN), a slot index, a symbol index, a switching duration, or a combination thereof, the method according to Clause 10.

[0137]

[0143] Clause 12. Receiving a beam switching gap location includes receiving an index to a predefined table of beam switching gap locations, a maximum switching duration for a particular beam switching gap location, or a combination thereof, the method according to Clause 11.

[0138]

[0144] Clause 13. A method of RF sensing performed by a UE, the method comprising: determining an opportunity for a network entity to perform RF sensing while the UE is not transmitting a signal, the opportunity including a guard period of the UE, a BWP switching period of the UE, or a beam switching period of the UE; and instructing the network entity of the opportunity for RF sensing.

[0139]

[0145] Clause 14. The method according to clause 13, wherein instructing an opportunity for RF sensing includes instructing a BWP switching period of the UE.

[0140]

[0146] Clause 15. The method according to clause 14, wherein instructing a BWP switching period of the UE includes instructing a switching delay for the UE to switch from a first BWP to a second BWP.

[0141]

[0147] Clause 16. The method according to clause 14 or 15, wherein instructing a BWP switching period of the UE includes instructing the BWP switching period based on at least one of RRC signaling related to the UE or a MAC entity at the start of a RACH procedure.

[0142]

[0148] Clause 17. The method according to any one of clauses 13 to 16, wherein instructing an opportunity for RF sensing includes instructing a beam switching period of the UE.

[0143]

[0149] Clause 18. The method according to clause 17, wherein instructing a beam switching period of the UE includes sending an indication of the beam switching period.

[0144]

[0150] Clause 19. The method according to clause 18, wherein sending an indication of the beam switching period includes sending a beam switching gap location identified by an SFN, a slot index, a symbol index, a switching duration, or a combination thereof.

[0145]

[0151] Clause 20. The method according to clause 19, wherein sending a beam switching gap location includes sending an index to a default table of beam switching gap locations, a maximum switching duration for a specific beam switching gap location, or a combination thereof.

[0146]

[0152] Clause 21. A network entity 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 at least one processor identifies an opportunity for RF sensing during which the UE does not transmit a signal, the opportunity including a guard period of the UE, a BWP switching period of the UE, or a beam switching period of the UE, and is configured to transmit an RF sensing signal, receive an RF sensing signal, or both during the opportunity for RF sensing via the at least one transceiver.

[0147]

[0153] Clause 22. The network entity according to clause 21, wherein the at least one processor is configured to identify a guard period of the UE, the guard period being associated with the SRS transmitted by the UE, in order to identify an opportunity for RF sensing.

[0148]

[0154] Clause 23. The network entity according to clause 22, wherein the at least one processor is configured to identify a guard period used after transmission of PUSCH by the UE and before transmission of SRS by the UE in order to identify the guard period of the UE.

[0149]

[0155] Clause 24. The network entity according to clause 22 or 23, wherein the at least one processor is configured to identify a guard period used between transmissions of SRSs transmitted within the same slot in order to identify the guard period of the UE.

[0150]

[0156] Clause 25. The network entity according to any one of Clauses 22 to 24, wherein at least one processor is configured to identify a guard period used after the last SRS transmitted within a slot and before the UE switches from uplink transmission to downlink transmission to identify the guard period of the UE.

[0151]

[0157] Clause 26. The network entity according to any one of Clauses 21 to 25, wherein at least one processor is configured to identify an opportunity for RF sensing by identifying a BWP switching period of the UE.

[0152]

[0158] Clause 27. The network entity according to Clause 26, wherein at least one processor is configured to identify a switching delay when the UE switches from a first BWP to a second BWP to identify the BWP switching period of the UE.

[0153]

[0159] Clause 28. The network entity according to Clause 26 or 27, wherein at least one processor is configured to identify a BWP switching period based on at least one of a BWP indicator in a DCI message to the UE, a BWP inactivity timer associated with the UE, RRC signaling related to the UE, or a MAC entity at the start of a RACH procedure to identify the BWP switching period of the UE.

[0154]

[0160] Clause 29. The network entity according to any one of Clauses 21 to 28, wherein at least one processor is configured to identify an opportunity for RF sensing by identifying a beam switching period of the UE.

[0155]

[0161] Clause 30. The network entity according to Clause 29, wherein at least one processor is configured to receive an indication of a beam switching period from the UE to identify the beam switching period of the UE.

[0156]

[0162] Clause 31. The network entity according to Clause 30, wherein at least one processor is configured to receive a beam switching gap location identified by an SFN, a slot index, a symbol index, a switching duration, or a combination thereof, in order to receive an instruction of a beam switching period from a UE.

[0157]

[0163] Clause 32. The network entity according to Clause 31, wherein at least one processor is configured to receive an index to a default table of beam switching gap locations, a maximum switching duration for a specific beam switching gap location, or a combination thereof, in order to receive a beam switching gap location.

[0158]

[0164] A UE, 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 at least one processor determines an opportunity for a network entity, such as a base station, to perform RF sensing while the UE is not transmitting a signal, the opportunity including a guard period of the UE, a BWP switching period of the UE, or a beam switching period of the UE, and instructs the network entity via the at least one transceiver of the opportunity for RF sensing.

[0159]

[0165] Clause 34. The UE according to Clause 33, wherein at least one processor is configured to instruct a BWP switching period of the UE in order to instruct an opportunity for RF sensing.

[0160]

[0166] Clause 35. The UE according to Clause 34, wherein at least one processor is configured to instruct a switching delay for the UE to switch from a first BWP to a second BWP in order to instruct a BWP switching period of the UE.

[0161]

[0167] Clause 36. The UE according to clause 34 or 35, wherein at least one processor is configured to indicate a BWP switching period for the UE based on at least one of RRC signaling related to the UE or a MAC entity at the start of a RACH procedure, so as to instruct the BWP switching period.

[0162]

[0168] Clause 37. The UE according to any one of clauses 33 to 36, wherein at least one processor is configured to indicate an opportunity for RF sensing by indicating a beam switching period of the UE.

[0163]

[0169] Clause 38. The UE according to clause 37, wherein at least one processor is configured to send an indication of a beam switching period for the UE so as to instruct the beam switching period.

[0164]

[0170] Clause 39. The UE according to clause 38, wherein at least one processor is configured to send a beam switching gap location identified by an SFN, a slot index, a symbol index, a switching duration, or a combination thereof in order to send an indication of a beam switching period.

[0165]

[0171] Clause 40. The UE according to clause 39, wherein at least one processor is configured to send an index to a default table of beam switching gap locations, a maximum switching duration for a specific beam switching gap location, or a combination thereof in order to send a beam switching gap location.

[0166]

[0172] Clause 41. A network entity comprising means for identifying an opportunity for RF sensing during which a UE does not transmit a signal, the opportunity including a guard period of the UE, a BWP switching period of the UE, or a beam switching period of the UE, and means for transmitting an RF sensing signal, receiving an RF sensing signal, or both, during the opportunity for RF sensing.

[0167]

[0173] Clause 42. A UE comprising means for determining an opportunity for a network entity to perform RF sensing while the UE does not transmit a signal, the opportunity including a guard period of the UE, a BWP switching period of the UE, or a beam switching period of the UE, and means for instructing the network entity of the opportunity for RF sensing.

[0168]

[0174] Clause 43. A non-transitory computer-readable medium storing computer-executable instructions that, when executed by a network entity, cause the network entity to identify an opportunity for RF sensing during which a UE does not transmit a signal, the opportunity including a guard period of the UE, a BWP switching period of the UE, or a beam switching period of the UE, and to transmit an RF sensing signal, receive an RF sensing signal, or both, during the opportunity for RF sensing.

[0169]

[0175] Clause 44. A non-transitory computer-readable medium storing computer-executable instructions that, when executed by a UE, cause the UE to determine an opportunity for a network entity to perform RF sensing while the UE does not transmit a signal, the opportunity including a guard period of the UE, a BWP switching period of the UE, or a beam switching period of the UE, and to instruct the network entity of the opportunity for RF sensing.

[0170]

[0176] Apparatus comprising a memory, a transceiver, and a processor communicatively coupled to the memory and the transceiver, wherein the memory, the transceiver, and the processor are configured to perform the method according to any one of clauses 1 to 20.

[0171]

[0177] Apparatus comprising means for performing the method according to any one of clauses 1 to 20.

[0172]

[0178] Non-transitory computer-readable medium storing computer-executable instructions, the computer-executable instructions including at least one instruction for causing a computer or a processor to perform the method according to any one of clauses 1 to 20.

[0173]

[0179] One of ordinary skill in the art will appreciate that information and signals 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 referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or optical particles, or any combination thereof.

[0174]

[0180] Furthermore, one of ordinary skill in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. One of ordinary skill 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.

[0175]

[0181] With respect to the aspects disclosed in this specification, the various exemplary logical blocks, modules, and circuits described may be implemented or performed using a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gates or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0176]

[0182] The methods, sequences, and / or algorithms described in connection with the aspects disclosed in this specification may be embodied directly in hardware, in software modules executed by a processor, or in a combination of the two. The software modules may reside in random access memory (RAM), flash memory, read-only memory (ROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), registers, hard disk, removable disk, 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., a UE). Alternatively, the processor and the storage medium may reside in the user terminal as discrete components.

[0177]

[0183] In one or more exemplary aspects, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, the functionality may be stored on or transmitted via a computer-readable medium as one or more instructions or code. A computer-readable medium includes both a computer storage medium and a communication medium 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 medium can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of the medium. 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 disk typically magnetically reproduces data, and disc optically reproduces data using lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0178]

[0184] Note that the above disclosure shows exemplary aspects of the present disclosure, but various changes and modifications can be made herein without departing from the scope of the present disclosure as defined by the appended claims. The functions, steps, and / or acts of the method claims according to the aspects of the present disclosure described herein need not be performed in any particular order. Further, elements of the present disclosure may be described or claimed in the singular, but the plural is contemplated unless expressly stated to the contrary.

Claims

1. A method of radio frequency (RF) sensing performed by a network entity, the method comprising: identifying an opportunity for RF sensing during which a user equipment (UE) does not transmit a signal, the opportunity including a guard period of the UE, a bandwidth part (BWP) switching period of the UE, or a beam switching period of the UE; transmitting an RF sensing signal, receiving an RF sensing signal, or both, during the opportunity for RF sensing; A method comprising the above.

2. The method according to claim 1, wherein identifying the opportunity for RF sensing includes identifying a guard period of the UE, the guard period being associated with sounding reference signals (SRSs) transmitted by the UE.

3. The method according to claim 2, wherein identifying the guard period of the UE includes identifying a guard period used after transmission of a physical uplink shared channel (PUSCH) by the UE and before transmission of an SRS by the UE.

4. The method according to claim 2, wherein identifying the guard period of the UE includes identifying a guard period used between transmissions of SRSs transmitted within the same slot.

5. The method according to claim 2, wherein identifying the guard period of the UE includes identifying a guard period used after the last SRS transmitted within a slot and before the UE switches from uplink transmission to downlink transmission.

6. The method according to claim 1, wherein identifying the opportunity for RF sensing includes identifying a BWP switching period of the UE.

7. The method according to claim 6, wherein identifying the BWP switching period of the UE includes identifying a switching delay when the UE switches from a first BWP to a second BWP.

8. Identifying the BWP switching period of the UE includes a BWP indicator in a downlink control information (DCI) message to the UE, a BWP inactivity timer associated with the UE, radio resource control (RRC) signaling related to the UE, or a media access control (MAC) entity at the start of a random access (RACH) procedure. The method according to claim 6, comprising identifying the BWP switching period based on at least one of them. **Claim 9** The method according to claim 1, wherein identifying the opportunity for RF sensing comprises identifying a beam switching period of the UE. **Claim 10** The method according to claim 9, wherein identifying the beam switching period of the UE comprises receiving an indication of the beam switching period from the UE. **Claim 11** The method according to claim 10, wherein receiving the indication of the beam switching period from the UE comprises receiving a beam switching gap location identified by a system frame number (SFN), a slot index, a symbol index, a switching duration, or a combination thereof. **Claim 12** The method according to claim 11, wherein receiving the beam switching gap location comprises receiving an index to a predefined table of beam switching gap locations, a maximum switching duration for a specific beam switching gap location, or a combination thereof. **Claim 13** The method according to claim 1, wherein the network entity comprises a base station or a gNodeB. **Claim 14** A method of radio frequency (RF) sensing performed by a user equipment (UE), the method comprising: determining an opportunity for a network entity to perform RF sensing while the UE is not transmitting a signal, the opportunity comprising a guard period of the UE, a bandwidth part (BWP) switching period of the UE, or a beam switching period of the UE; instructing the network entity of the opportunity for RF sensing; comprising. **Claim 15** The method according to claim 14, wherein instructing the opportunity for RF sensing comprises instructing a BWP switching period of the UE. **Claim 16** The method according to claim 15, wherein instructing the BWP switching period of the UE comprises instructing a switching delay for the UE to switch from a first BWP to a second BWP. **Claim 17** Instructing the BWP switching period of the UE is radio resource control (RRC) signaling related to the UE, or a media access control (MAC) entity at the start of a random access (RACH) procedure The method according to claim 15, comprising instructing the BWP switching period based on at least one of them.

18. The method according to claim 14, wherein instructing the opportunity for RF sensing comprises instructing a beam switching period of the UE.

19. The method according to claim 18, wherein instructing the beam switching period of the UE comprises sending an instruction of the beam switching period.

20. The method according to claim 19, wherein sending the instruction of the beam switching period comprises sending a beam switching gap location identified by a system frame number (SFN), a slot index, a symbol index, a switching duration, or a combination thereof.

21. The method according to claim 20, wherein sending the beam switching gap location comprises sending an index to a predefined table of beam switching gap locations, a maximum switching duration for a specific beam switching gap location, or a combination thereof.

22. The method according to claim 14, wherein the network entity comprises a base station or a gNodeB.

23. A network entity, 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 at least one processor identifies an opportunity for radio frequency (RF) sensing during which a user equipment (UE) does not transmit a signal, the opportunity including a guard period of the UE, a bandwidth part (BWP) switching period of the UE, or a beam switching period of the UE, and transmits an RF sensing signal, receives an RF sensing signal, or both, via the at least one transceiver during the opportunity for RF sensing. A network entity configured as such.

24. The network entity according to claim 23, wherein, to identify the opportunity for RF sensing, the at least one processor is configured to identify a guard period of the UE, the guard period being associated with sounding reference signals (SRSs) transmitted by the UE.

25. The network entity according to claim 23, wherein, to identify the opportunity for RF sensing, the at least one processor is configured to identify a BWP switching period of the UE.

26. The network entity according to claim 23, wherein, to identify the opportunity for RF sensing, the at least one processor is configured to identify a beam switching period of the UE.

27. The network entity according to claim 23, comprising a base station or a gNodeB.

28. A user equipment (UE), 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 determines an opportunity for a network entity to perform radio frequency (RF) sensing while the UE is not transmitting a signal, the opportunity including a guard period of the UE, a bandwidth part (BWP) switching period of the UE, or a beam switching period of the UE, and instructs the network entity via the at least one transceiver of the opportunity for RF sensing. A user equipment (UE) configured as such.

29. The UE according to claim 28, wherein, to instruct the opportunity for RF sensing, the at least one processor is configured to instruct a BWP switching period of the UE.

30. The UE according to claim 28, wherein, to instruct the opportunity for RF sensing, the at least one processor is configured to instruct a beam switching period of the UE.

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