Beam squint radar operation with reconfigurable intelligent surface device

Abstract

This disclosure provides systems, devices, apparatus, and methods, including computer programs encoded on storage media, for radar sensing. A wireless device transmits (314, 414), towards a reconfigurable intelligent surface, RIS, device (122), a wideband radar signal. The wireless device receives (320, 420) a first reflection of the wideband radar signal, the first reflection indicating a plurality of narrowband beam directions associated with a first object detection. The wireless device transmits (330, 430), towards the RIS device (122), a narrowband radar signal corresponding to one or more of the plurality of narrowband beam directions. The wireless device receives (334, 434) a second reflection of the narrowband radar signal, the second reflection being associated with a second object detection.

Description

BEAM SQUINT RADAR OPERATION WITH RECONFIGURABLE INTELLIGENT SURFACE DEVICECROSS REFERENCE

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 580,832, filed 6 September 2023, the disclosure of which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] The present disclosure relates generally to wireless communication, and more particularly, to radar operations with a reconfigurable intelligent surface (RIS) and / or an adaptive-phase changing device (APD).BACKGROUND

[0003] The Third Generation Partnership Project (3GPP) specifies a radio interface referred to as fifth generation (5G) new radio (NR) (5G NR). An architecture for a 5G NR wireless communication system includes a 5G core (5GC) network, a 5G radio access network (5G-RAN), a user equipment (5G UE), etc. The 5G NR architecture seeks to provide increased data rates, decreased latency, and / or increased capacity compared to prior generation cellular communication systems.

[0004] Wireless communication systems, in general, provide various telecommunication services (e.g., telephony, video, data, messaging, etc.) based on multiple-access technologies, such as orthogonal frequency division multiple access (OFDMA) technologies, that support communication with multiple UEs. Improvements in mobile broadband continue the progression of such wireless communication technologies. For example, adaptive phase-changing devices (APDs) and reconfigurable intelligent surfaces (RISs) are being implemented for next generation communication systems (e.g.. sixth generation (6G) wireless technology), and in particular for radar sensing. Radar sensing such as in densely populated urban environments, for example, can be challenging because a presence of blockers (e.g., buildings, trees, pedestrians, vehicles, etc.) can potentially block a line-of-sight (LOS) between a radar transmitter and a target / object. These blockers can create shadow regions, which refers to a region where the target cannot be reached by a radar signal in a direct path without reflection.BRIEF SUMMARY

[0005] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects. This summary neither identifies key or critical elements of all aspects nor delineates the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

[0006] Adaptive phase-changing devices (APDs) and reconfigurable intelligent surfaces (RISs) can extend radar coverage into shadow regions by reflecting and / or steering a received radar signal from a surface of the APD / RIS towards a target / object. However, wideband millimeter wave (mmWave) (or terahertz (THz) wave or higher) communications supported by the APD / RIS suffer from the beam squinting effect. Beam squinting is a phenomenon caused by the frequency dependence of the magnitude of the phase shift in analog beamforming. Beam squinting effect can adversely affect the received radar signal that in turn can affect the angular resolution of the radar system. For example, for a radar system with phased array antennas utilizing wideband radar signals, the phase difference between signals transmitted from multiple antenna elements varies because the phase difference depends on the instantaneous carrier frequency. In this situation where the radar system utilizes the wideband radar signals, the instantaneous carrier frequency is swept across the band. The varying phase difference causes a varying beam direction (also known as beam squinting). Beam squinting induces errors in the estimation of the direction of arrival (DOA) and degrades the antenna gain.

[0007] Aspects of the present disclosure address the above-noted and other deficiencies by implementing a two-step procedure for the radar sensing, such as with the RIS. In one example, the UE receives, from the network entity, beam squinting information including at least one of a beam squinting angle or beam widths as a function of the RIS phase vectors. The UE transmits, to the network entity, a request message for a resource grant to perform wideband radar processing. The UE transmits a wideband radar signal using the resource grant. The UE transmits a second request message to perform narrowband radar processing when the UE detects a reflection of the wideband signal. In another example, the network entity is the transmitter of the radar signal, and the network entity transmits a narrowband radar signal when the network entity detects the wideband signal.

[0008] According to some aspects, a wireless device transmits towards an RIS device, a wideband radar signal. The wireless device receives a first reflection of the wideband radar signal, the first reflection indicating a plurality' of narrowband beam directions associated with a first object detection. The wireless device transmits, towards the RIS device, a narrowband radar signal corresponding to one or more of the plurality of narrowband beam directions. The wireless device receives a second reflection of the narrowband radar signal, the second reflection being associated with a second object detection.

[0009] According to some aspects, a RIS device, receives, from a network entity, a wideband radar signal to sweep a RIS phase vector. The RIS device measures a reflection of the wideband radar signal for beam squinting angles associated with the RIS phase vector. The RIS device transmits, to the network entity7, RIS beam squinting information including the beam squinting angles associated with the reflection of the wideband radar signal.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 illustrates a diagram of a wireless communications system that includes a plurality of user equipments (UEs) and network entities in communication over one or more cells according to an embodiment.

[0011] FIG. 2A-2B are diagrams illustrating example environments for implementing beam squint radar operation, according to some embodiments.

[0012] FIG. 3 is a signaling diagram illustrating communications between a user equipment (UE). a reconfigurable intelligent surface (RIS) device, and a network entity7for beam squint radar operation according to an embodiment.

[0013] FIG. 4 is a signaling diagram illustrating communications between a RIS device and a network entity for beam squint radar operation according to an embodiment.

[0014] FIG. 5 is a flowchart of a method of wireless communication at a UE according to an embodiment.

[0015] FIG. 6 is a flowchart of a method of wireless communication at a network entity7according to an embodiment.

[0016] FIG. 7 is a flowchart of a method of wireless communication at the RIS device according to an embodiment.

[0017] FIG. 8 is a diagram illustrating a hardware implementation for an example UE apparatus according to some embodiments.

[0018] FIG. 9 is a diagram illustrating a hardware implementation for one or more example network entities according to some embodiments.DETAILED DESCRIPTION

[0019] FIG. 1 illustrates a diagram 100 of a wireless communications system associated with a plurality of cells 190. The wireless communications system includes user equipments (UEs) 102 and base stations / network entities 104. Some base stations may include an aggregated base station architecture and other base stations may include a disaggregated base station architecture. The aggregated base station architecture utilizes a radio protocol stack that is physically or logically integrated within a single radio access network (RAN) node. A disaggregated base station architecture utilizes a protocol stack that is physically or logically distributed among two or more units (e.g., radio unit (RU) 106, distributed unit (DU) 108, central unit (CU) 110). For example, a CU 110 is implemented within a RAN node, and one or more DUs 108 may be co-located with the CU 110, or alternatively, may be geographically or virtually distributed throughout one or multiple other RAN nodes. The DUs 108 may be implemented to communicate with one or more RUs 106. Any of the RU 106, the DU 108 and the CU 110 can be implemented as virtual units, such as a virtual radio unit (VRU), a virtual distributed unit (VDU). or a virtual central unit (VCU). The base station / network entity 104 (e.g., an aggregated base station or disaggregated units of the base station, such as the RU 106 or the DU 108), may be referred to as a transmission reception point (TRP).

[0020] Operations of the base station 104 and / or network designs may be based on aggregation characteristics of base station functionality. For example, disaggregated base station architectures are utilized in an integrated access backhaul (IAB) network, an open-radio access network (O-RAN) network, or a virtualized radio access network (vRAN), which may also be referred to a cloud radio access network (C- RAN). Disaggregation may include distributing functionality across the two or more units at various physical locations, as well as distributing functionality for at least one unit virtually, which can enable flexibility in network designs. The various units of the disaggregated base station architecture, or the disaggregated RAN architecture, can be configured for wired or wireless communication with at least one other unit. For example, the base stations 104d, 104e and / or the RUs 106a, 106b, 106c. 106dmay communicate with the UEs 102a. 102b. 102c. 102d, and / or 102s via one or more radio frequency (RF) access links based on a Uu interface. In examples, multiple RUs 106 and / or base stations 104 may simultaneously serve the UEs 102, such as by intracell and / or inter-cell access links between the UEs 102 and the RUs 106 / base stations 104.

[0021] The RU 106, the DU 108, and the CU 110 may include (or may be coupled to) one or more interfaces configured to transmit or receive information / signals via a wired or wireless transmission medium. For example, a wired interface can be configured to transmit or receive the information / signals over a wired transmission medium, such as via the fronthaul link 160 between the RU 106d and the baseband unit (BBU) 1 12 of the base station 104d associated with the cell 190d. The BBU 112 includes a DU 108 and aCU 110, which may also have a wired interface (e g., midhaul link) configured between the DU 108 and the CU 110 to transmit or receive the information / signals between the DU 108 and the CU 110. In further examples, a wireless interface, which may include a receiver, a transmitter, or a transceiver, such as an RF transceiver, configured to transmit and / or receive the information / signals via the wireless transmission medium, such as for information communicated between the RU 106a of the cell 190a and the base station 104e of the cell 190e via cross-cell communication beams 136-138 of the RU 106a and the base station 104e.

[0022] The RUs 106 may be configured to implement lower layer functionality. For example, the RU 106 is controlled by the DU 108 and may correspond to a logical node that hosts RF processing functions, or lower layer PHY functionality, such as execution of fast Fourier transform (FFT). inverse FFT (iFFT), digital beamforming, physical random access channel (PRACH) extraction and filtering, etc. The functionality of the RU 106 may be based on the functional split, such as a functional split of lower layers.

[0023] The RUs 106 may transmit or receive over-the-air (OTA) communication with one or more UEs 102. For example, the RU 106b of the cell 190b communicates with the UE 102b of the cell 190b via a first set of communication beams 132 of the RU 106b and a second set of communication beams 134b of the UE 102b, which may correspond to inter-cell communication beams or, in some examples, cross-cell communication beams. For instance, the UE 102b of the cell 190b may communicate with the RU 106a of the cell 190a via a third set of communication beams 134a of the UE 102b and a fourth set of communication beams 136 of the RU 106a. DUs 108 cancontrol both real-time and non-real-time features of control plane and user plane communications of the RUs 106.

[0024] Any combination of the RU 106, the DU 108, and the CU 110, or reference thereto individually, may correspond to a base station 104. Thus, the base station 104 may include at least one of the RU 106, the DU 108, or the CU 110. The base stations 104 provide the UEs 102 with access to a core network. The base stations 104 may relay communications between the UEs 102 and the core network (not shown). The base stations 104 may be associated with macrocells for higher-power cellular base stations and / or small cells for lower-power cellular base stations. For example, the cell 190e may correspond to a macrocell, whereas the cells 190a-190d may correspond to small cells. Small cells include femtocells, picocells, microcells, etc. A network that includes at least one macrocell and at least one small cell may be referred to as a “heterogeneous network.”

[0025] Transmissions from a UE 102 to a base station 104 / RU 106 are referred to as uplink (UL) transmissions, whereas transmissions from the base station 104 / RU 106 to the UE 102 are referred to as downlink (DL) transmissions. Uplink transmissions may also be referred to as reverse link transmissions and downlink transmissions may also be referred to as forward link transmissions. For example, the RU 106d utilizes antennas of the base station 104d of cell 190d to transmit a downlink / forward link communication to the UE 102d or receive an uplink / reverse link communication from the UE 102d based on the Uu interface associated with the access link between the UE 102d and the base station 104d / RU 106d.

[0026] Communication links between the UEs 102 and the base stations 104 / RUs 106 may be based on multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. The communication links may be associated with one or more carriers. The UEs 102 and the base stations 104 / RUs 106 may utilize a spectrum bandwidth of Y MHz (e.g., 5. 10, 15, 20, 100, 400, 800, 1600, 2000, etc. MHz) per earner allocated in a carrier aggregation of up to a total of Yx MHz, where x component carriers (CCs) are used for communication in each of the uplink and downlink directions. The carriers may or may not be adjacent to each other along a frequency spectrum. In examples, uplink and downlink carriers may be allocated in an asymmetric manner, with more or fewer carriers allocated to either the uplink or the downlink. A primary component carrier and one or more secondary7component carriers may be included in the componentearners. The primary component earner may be associated with a primary cell (PCell) and a secondary component carrier may be associated with a secondary cell (SCell).

[0027] Some UEs 102, such as the UEs 102a and 102s, may perform device-to-device (D2D) communications over sidelink. For example, a sidelink communication / D2D link utilizes a spectrum for a wireless wide area network (WWAN) associated with uplink and downlink communications. Such sidelink / D2D communication may be performed through various wireless communications systems, such as wireless fidelity (Wi-Fi) systems, Bluetooth systems, Long Term Evolution (LTE) systems, New Radio (NR) systems, etc.

[0028] The UEs 102 and the base stations 104 / RUs 106 may each include a plurality of antennas. The plurality of antennas may correspond to antenna elements, antenna panels, and / or antenna arrays that may facilitate beamforming operations. For example, the RU 106b transmits a downlink beamformed signal based on a first set of communication beams 132 to the UE 102b in one or more transmit directions of the RU 106b. The UE 102b may receive the downlink beamformed signal based on a second set of communication beams 134b from the RU 106b in one or more receive directions of the UE 102b. In a further example, the UE 102b may also transmit an uplink beamformed signal (e.g.. sounding reference signal (SRS)) to the RU 106b based on the second set of communication beams 134b in one or more transmit directions of the UE 102b. The RU 106b may receive the uplink beamformed signal from the UE 102b in one or more receive directions of the RU 106b. The UE 102b may perform beam training to determine the best receive and transmit directions for the beamformed signals. The transmit and receive directions for the UEs 102 and the base stations 104 / RUs 106 may or may not be the same.

[0029] In further examples, beamformed signals may be communicated between a first base station / RU 106a and a second base station 104e. For instance, the base station 104e of the cell 190e may transmit a beamformed signal to the RU 106a based on the communication beams 138 in one or more transmit directions of the base station 104e. The RU 106a may receive the beamformed signal from the base station 104e of the cell 190e based on the RU communication beams 136 in one or more receive directions of the RU 106a. In further examples, the base station 104e transmits a downlink beamformed signal to the UE 102e based on the communication beams 138 in one or more transmit directions of the base station 104e. The UE 102e receives the downlink beamformed signal from the base station 104e based on UE communicationbeams 130 in one or more receive directions of the UE 102e. The UE 102e may also transmit an uplink beamformed signal to the base station 104e based on the UE communication beams 130 in one or more transmit directions of the UE 102e, such that the base station 104e may receive the uplink beamformed signal from the UE 102e in one or more receive directions of the base station 104e.

[0030] The base station 104 may include and / or be referred to as a network entity. That is, ‘'network entity” may refer to the base station 104 or at least one unit of the base station 104, such as the RU 106, the DU 108. and / or the CU 110. The base station 104 may also include and / or be referred to as a next generation evolved Node B (ng- eNB), a next generation NB (gNB), an evolved NB (eNB), an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a TRP, a network node, network equipment, or other related terminology. The base station 104 or an entity at the base station 104 can be implemented as an IAB node, a relay node, a sidelink node, an aggregated (monolithic) base station, or a disaggregated base station including one or more RUs 106, DUs 108, and / or CUs 110. A set of aggregated or disaggregated base stations may be referred to as a next generation-radio access network (NG-RAN). In some examples, the UE 102a operates in dual connectivity (DC) with the base station 104e and the base station / RU 106a. In such cases, the base station 104e can be a master node and the base station / RU 160a can be a secondary node.

[0031] One or more UEs 102 may include a radar device 103e and one or more base stations 104e may include a radar device 103g. The UEs 102 may communicate with the base stations 104 via one or more radio frequency (RF) access links 178. A downlink portion of the access link 178 may be combined with a radar signal to result in a combined radar and communication signal. This combined radar and communication signal may use orthogonal time frequency space (OTFS) modulation or orthogonal frequency-division multiplexing (OFDM) modulation. The UEs 102 may transmit to the network entity 104, information using an uplink portion of the access link 178. The UEs 102 can perform radar sensing for imaging an environment or determining information about an object based a reflection 176 of the radar signal 174 that is reflected off a reconfigurable intelligent surface (RIS) device 122. The network entity 104e communicates with the RIS device 122 using access links 179 for control and / or data communication.

[0032] The R1S device 122, also called intelligent reflecting surfaces (IRS), which include multiple antenna elements tunable to interact with electromagnetic waves (passively or actively). For example, a passive RIS may include an array of subwavelength-sized of antenna elements having properties such as reflection, negative refraction, absorption, or scattering, among others. A RIS controller 164 applies or configures phase vectors of the RIS elements to alter the reflective properties (e.g., varying output directions of radio wave reflections). In some cases, the configuration of RIS elements uses similar principles as beamforming (using the antenna elements to control the direction of a wave-front by weighting the magnitude and / or phase). As such, even when a device and an RIS maintain relatively constant positions with each other, the device can configure the RIS to generate reflective beams in various directions by controlling the phase vectors and other configuration aspects at the RISs. In some examples, RIS devices and adaptive phase-changing devices (APDs) may be used interchangeably in the description.

[0033] Still referring to FIG. 1, in certain aspects, any of the UEs 102 may include a UE RIS radar component 140 configured to transmit, towards the RIS device 122, a wideband radar signal, and receive a first reflection of the wideband radar signal. The first reflection indicates a plurality of narrowband beam directions associated with a first object detection. The UE RIS radar component 140 is also configured to transmit towards the RIS device 122, a narrowband radar signal corresponding to one or more of the plurality of narrowband beam directions and receive a second reflection of the narrowband radar signal. The second reflection is associated with a second object detection.

[0034] In certain aspects, any of the base stations 104 or a network entity of the base stations 104 may include a base station (BS) RIS radar component 150 configured to transmit, towards a RIS device 122, a wideband radar signal and receive a first reflection of the wideband radar signal. The first reflection indicates a plurality of narrowband beam directions associated with a first object detection. The BS RIS radar component 150 is also configured to transmit towards the RIS device 122, a narrowband radar signal corresponding to one or more of the plurality of narrowband beam directions, and receive a second reflection of the narrowband radar signal. The second reflection is associated with a second object detection.

[0035] In certain aspects, any of the RISs 122 may include a RIS radar component 166 configured to receive, from a network entity 104, a wideband radar signal to sweep aRIS phase vector, measure a reflection of the wideband radar signal for beam squinting angles associated with the RIS phase vector, and transmit, to the network entity 104, RIS beam squinting information including the beam squinting angles associated with the reflection of the wideband radar signal.

[0036] Accordingly, FIG. 1 describes a wireless communication system that may be implemented in connection with aspects of one or more other figures described herein. Further, although the following description may be focused on 5G NR, the concepts described herein may be applicable to other similar areas, such as 5G- Advanced and future versions. LTE, LTE-advanced (LTE-A), and other wireless technologies, such as 6G.

[0037] FIG. 2A illustrates an example environment 200 for implementing beam squint radar operation, according to some embodiments. The environment 200 includes UEs 102 (e.g., corresponding to FIG. 1 element 102e) and a network entity 104 (e.g., corresponding to FIG. 1 element 104e). The UE 102 may be implemented as any suitable computing or electronic device, such as a mobile communication device, cellular phone, gaming device, navigation device, media device, laptop computer, desktop computer, tablet computer, smart appliance, vehicle-based communication system, or an Intemet-of-Things (loT) device.

[0038] Referring to FIG. 2A, the UE 102 can act as a radar transmitter to perform radar sensing with an RIS device 122. Radar sensing can be used for imaging an environment or determining information about an obj ect 116 in the environment based on range, Doppler, and / or angle information determined from a reflection of the radar signal 174. The radar signal 174 includes a defined waveform, such as a frequency modulated continuous wave (FMCW), a pulse waveform, an OTFS waveform, or a chirp waveform, among other examples of a defined waveform. Radar sensing can be employed for automotive radar, e.g., detecting an environment around a vehicle, nearby vehicles or items, detecting information for smart cruise control, collision avoidance, etc. Radar signal sensing can also be employed for gesture recognition, e.g., a human activity recognition, a hand motion recognition, a facial expression recognition, a keystroke detection, sign language detection, etc. Radar signal sensing can be employed to acquire contextual information, e.g., location detection, tracking, determining directions, range estimation, etc. Radar sensing can be employed to image an environment, e.g., to provide a 3-dimensional (3D) map for virtual reality (VR) or augmented reality' (AR) applications. Radar devices can be employed toprovide high resolution localization, e.g.. for industrial Intemet-of-things (loT) applications.

[0039] The network entity 104 communicates with the UEs 102 using access links 178 (e.g., wireless downlink 178 A) for control and / or data communication. For example, the network entity 104 communicates control information and downlink data to the UEs 102. The UEs 102 communicate 178B control information and uplink data to the network entity 104. A dow nlink portion 178A or uplink portion 178B of an access link 178 may be combined with a radar signal resulting in a combined radar and communication signal. The network entity 104 communicates with the RIS device 122 using access links 179 for control and / or data communication. For example, the network entity 104 communicates control information to the RIS device 122.

[0040] FIG. 2A show s an example 200 in which the UE 102 is performing a radar sensing with the RIS device 122 to sense an object 116. The object 116 may be blocked by an obstacle 114 (e.g.. walls, windows, water vapor, human bodies, etc.). The obstacle 114 can be stationary or moving. Therefore, the obstacle 114 prevents the UE 102 to have a line-of-sight (LOS) with the object 116. In another situation, the object 116 may be located within a densely populated area with a significant pathloss. For example, the densely populated area may be an urban environment that is crowded with stationary or moving objects. Because of the densely populated area, the channel attenuation may be significant causing a w eak reflection of the signal received by the radar receiver. In a further situation, the obstacle 114 can cause a w eak wireless signal coverage that may deteriorate the quality-of-service. Therefore, an RIS device is deployed with the radar system to support the radar sensing of the object to overcome the issues as described above.

[0041] As shown in FIG. 2A, the RIS device 122 acts as an assistor to assist the UE 102 to perform radar sensing to sense the object 116 that does not have a LOS with the radar transmitter (e.g., UE 102) by establishing a radar-object propagation path. In this manner, the RIS device 122 can assist radar sensing operation in the absence of a LOS between the radar transmitter and the object by extending a radar coverage between the radar transmitter and the object. For example, the RIS device 122 may be mounted on a building to detect objects (e.g., drones) that may fall in a non-line-of-sight (N-LOS) area because of tall buildings.

[0042] Because of the presence of the obstacle 114 betw een the UE 102 and the object 116, the UE 102 transmits the radar signal 174 towards the RIS device 122 to establisha radar-object propagation path. The RIS device 122 receives the radar signal 174 and reflects the radar signal 174 off the RIS surface and directs a reflected portion of the radar signal towards the object 116. The radar signal 174 reaches the surface of the RSI device 122 with a certain angle of incidence and the radar signal 174 can be redirected towards the object 116 with a certain angle of reflection. The RIS device 122 adaptively adjusts a phase of each reflecting element to amplify the signal the RIS device 122 receives towards a direction of the object 116. The UE 102 receives a reflection of the reflected portion of radar signal 174 reflected from the object 116 as well as the radar signal directly (unreflected). In response to receiving the radar signal 174 (directly or reflected), the UE 102 performs radar processing to determine radar signal measurement information which includes information about the object 116. Based on the radar signal measurement information, the UE 102 calculates a location of the object 116.

[0043] In some implementations (not shown in the environment 200 of FIG. 2A). although one RIS device 122 is shown in FIG. 2A, multiple RIS devices may be deployed to perform radar sensing with the UE 102 and / or the network entity 104 for supporting new wireless technology applications and capabilities. The use of the RIS devices may contribute to enhanced capacity, coverage, positioning, security, sensing, wireless power transfer, and ambient backscattering capabilities of wireless technology applications and capabilities. For example, the use of the RIS device 122 may help generate a surrounding map with high precision and accuracy (as the radar sensing assisted by the RIS device 122 enable the UE 102 to perform radar sensing behind obstacles, such as the obstacle 114 in the environment 200 of FIG. 2A).

[0044] Thus, the UE 102, the network entity 104, and the RIS device 122 performing the radar sensing may overcome the limitations associated with conventional object detection techniques either by the network entity 104 or the UE 102. In addition, the UE 102 and / or the network entity 104 may add communication information to the radar signal for a combined radar and communication signal. Variants of FIG. 2B include the network entity 104 performing object detection by transmitting the radar signal and the network entity 104 detecting reflections of the radar signal from the object.

[0045] FIG. 2B shows the network entity 104 transmitting the radar signal 174 for radar sensing. As shown in FIG. 2B, however, a network entity 104 acts as radar receiver to perform radar sensing with the RIS device 122.

[0046] Accordingly. FIGs. 1 to 2B describe example environments in which various aspects of radar sensing may be implemented in connection with aspects of one or more other figures described herein, such as aspects illustrated in FIGs. 3-8.

[0047] FIG. 3 is a signaling diagram that illustrates example scenario 300 for radar sensing with a UE 102 as both a radar-transmitter and a radar-receiver, according to some embodiments as described in FIG. 2A. The network entity 104 may correspond to a base station or a unit of a base station, such as the RU 106, the DU 108, the CU 110, etc. While the example scenario 300 illustrates a RIS device 122, other implementations may include an APD.

[0048] The network entity 104 transmits 301 A, to the RIS device 122, a wideband radar signal to sweep a RIS phase vector. In one example, the network entity 104 transmits 301 A the wideband radar signal towards the RIS device 122 to obtain a plurality of RIS phase vectors. The RIS device 122 includes a number of elements (e.g., an array of surface elements) to reflect, and coherently combine and beamform the wideband radar signal. Each surface element has a reflection coefficient and a phase shift. In one example, a RIS controller 164 (shown in FIG. 1) applies or configures the phase vectors of the surface elements to alter the reflective properties (e.g., varying output directions of radio wave reflections) of the RIS device 122. The network entity 104 may determine the RIS phase vector based on information (e.g., location, position, orientation) from reflections of the wideband radar signal. For example, the network entity 104 may determine beam squinting information (e.g., beam squinting angles, beam widths, etc.) based on the wideband radar signal without the information from the RIS device 122.

[0049] In some implementations, the RIS device 122 measures 301B a reflection of the wideband radar signal for beam squinting angles associated with the RIS phase vector. The network entity 104 can adjust or modify the beam squinting information and the RIS phase vectors based on the information from the RIS device 122. In one example, based on the plurality of the RIS phase vector, the RIS device 122 performs measurements (e.g., RIS reflected signal direction) to determine a beam squinting angle associated with the RIS phase vector. In another example, based on the plurality of the RIS phase vector, the RIS device 122 determines beam widths as a function of the RIS phase vector. In this manner, the RIS device 122 can perform a calibration of the beam squinting effect based on the measurement of the RIS reflected signal direction.

[0050] In some implementations, the network entity 104, receives 301C, from the RIS device 122, RIS beam squinting information including the beam squinting angles associated with the reflection of the wideband radar signal. The RIS beam squinting information may also include beam widths as a function of the RIS phase vector. Therefore, as noted above, the network entity 104 can determine 302 the beam squinting information with or without the information from the RIS device 122.

[0051] The UE 102 may transmit 304, to the network entity 104, a radar processing capability message that indicates radar capabilities supported by the UE for the radar sensing with the RIS device 122. For example, the UE 102 optionally transmits 304 to the network entity 104 a radar capability message (e.g., UECapabilitylnformation message) that indicates UE radar capabilities. The radar capabilities may include a field for indicating at least one of: a UE capability to perform radar sensing with the RIS device; a UE capability to transmit or receive the radar signal; or a minimum delay between a reception of a physical downlink control channel (PDCCH) grant and a time that the UE 102 performs a radar measurement report transmission. The radar capability7message may also include at least one field for indicating at least one of: a supported radar signal band and associated bandwidth, a supported radar waveform, an antenna array capability, a maximum radar Doppler resolution, a maximum radar range resolution, or a maximum angular resolution.

[0052] The network entity 104 transmits 306, to the UE 102, RIS beam squinting information. The RIS beam squinting information may include a beam squinting angle or beam widths as a function of RIS phase vectors.

[0053] The UE 102 transmits 308. to the network entity 104, a first radar request message for requesting a resource grant to perform wideband radar sensing with the RIS device 122. In one example, the first request message includes a field indicating a phase vector map for mapping RIS phase vectors to a region of interest associated with the object detection. The UE 102 may indicate in the first request message the desired RIS phase vectors corresponding to a certain region of interest for the radar detection of the object 116.

[0054] The RIS device 122 may not be specified by the UE 102 in the request message, such that the network entity 104 has to select the RIS device 122 to assist the UE 102 with the radar sensing. For example, if the UE 102 determines to perform radar sensing and transmits 308 the radar request message to the network entity' 104, the network entity' 104 can select the RIS device 122 to perform radar sensing with theUE 102. In some examples, the serving network entity 104 determines to perform the radar sensing directly with the UE 102. In some other examples, the network entity 104 has the information associated with the deployment of the RIS devices 122 within the coverage area, and selects the RIS device 122 based on the location of the UE 102 and / or the object to be detected by radar sensing.

[0055] The network entity 104 may select, based on the request message, the RIS device 122 to assist the UE 102 with the radar sensing. For example, the network entity 104 can select the RIS device 122 based on location information of the RIS device 122. For example, the network entity 104 refers to information about the UE 102 included in the radar request message (e.g., the position of the UE 102, a velocity of the UE 102, or an orientation of the UE 102) to select the RIS device 122 that can provide a LOS between the UE 102 and the object 116. In some other examples, the network entity 104 may select the RIS device 122 that is the closest to the UE 102.

[0056] The UE 102 receives 310 a grant indicating resources for RIS wideband radar processing. In some aspects, the resources indicate the specific time slot that the UE 102 can transmit the wideband radar signal. For example, the UE 102 may receive from the network entity 104, downlink control information (DCI) that indicates at least one of: a frequency resource (e.g., frequency domain resource assignment), a timing resource (e.g., time domain resource assignment), power control command, or a radar w aveform. In some examples, the UE 102 does not receive an identity of the RIS device 122 that the network entity 104 has selected to assist the UE 102 with the radar sensing. The UE 102 utilizes the granted resources for radar signaling and relies on the network entity 104 to receive and relay information related to the radar signaling as feedback to the UE 102. In some embodiments, the resources for RIS wideband radar processing further indicates a conditional resource for transmission of the narrowband radar signal. For example, the resources may include conditional resources (time / frequency resource assignments) for the narrowband radar signal for the UE 102 to use if the UE 102 detects an object based on the wideband radar signal.

[0057] The netw ork entity 104 transmits 312, to the RIS device 122, the RIS phase vector.In one example, the network entity 104 may transmit 312, to the RIS device 122, a radio resource control (RRC) configuration message. For example, the RIS device 122 receives 312, from the network entity 104, an RRC message (e.g., RRCReconfiguration message). The RRCReconfigurcition message may include phase parameters (e.g., phase vectors) which configure the RIS device 122 to reflectboth the radar signal 174 and potential communication signals to and from the object 116. The RRC configuration message indicates the time slot that the RIS device 122 should reflect the wideband radar signal. The time slot may be the same time slot for the transmission 314 of the wideband radar signal as described below. In some other examples, the network entity 104 may transmit 312 a physical downlink control channel (PDCCH) downlink control information (DCI) that indicates the RIS phase vector. Responsive to receiving 310 the resource grants, the UE 102 performs radar sensing using the RIS device 122. For example, the UE 102 transmits 314 towards the RIS device 122 a wideband radar signal over-the-air using the granted radar resources. For example, as described above, the UE 102 transmits the wideband radar signal on the specific time slot indicated in the granted radar resources. As mentioned previously, the radar signal may be an OFDM radar signal, an OTFS radar signal, a frequency-modulated continuous-wave (FMCW) radar signal, a pulsed radar signal, or other type of radar signal. Waveform parameters (e.g., a waveform identifier) as indicated in the radar resource grants define the radar signal. For example, the network entity 104 transmits 310, to the UE 102, the waveform identifier via the radar resource grants. The waveform identifier indicates the type of waveform to be utilized for the radar signal. During radar sensing, the radar signal travels through the air and may impinge on reflective surfaces of the RIS device 122. The RIS device 122 reflects or redirects 316 the wideband radar signal towards object 116.

[0058] The UE 102 receives 320 the reflected portion of the wideband radar signal that is reflected off the object 116.

[0059] Based on the reflection of the wideband radar signal, the UE 102 detects 322 narrowband beam directions associated with an object detection. For example, if the UE 102 detects 322 narrowband beam directions based on the reflection of the wideband radar signal off the obj ect 116, the UE 102 can request for narrowband radar processing. When the UE 102 receives the reflection of the wideband radar signal during the detection 322, the reflection of the wideband radar signal includes the impact of the beam squinting effect. The beam squinting effect may cause the UE 102 to identify a plurality of narrowband beam directions, one of which is the narrowband beam direction that the UE 102 should use for the detection of the object 116. Therefore, the UE 102 tests each of the plurality of narrowband beam directions (identified from the beam squinting) to determine the correct narrowband beam direction to use for the object detection.

[0060] The UE 102 transmits 324, to the network entity 104. a request message for a resource grant to perform the narrowband radar processing. The UE 102 can use the narrowband radar signal for a higher angular resolution obj ect detection. The UE 102 can determine the frequency range of the narrowband radar signal based on the beam squinting information. In some examples, the UE 102 can request multiple narrowband radar signals to perform radar sensing in different directions.

[0061] The UE 102 receives 326, from the network entity 104, control signaling indicating the resource grant for the transmitting 330 the narrowband radar signal. In some aspects, the UE 102 may receive from the network entity’ 104, downlink control information (DO) that indicates at least one of a frequency resource (e.g., frequency domain resource assignment), a timing resource (e.g., time domain resource assignment), pow er control command, or a radar w aveform for the narrowband radar signal.

[0062] The network entity 104 transmits 328. to the RIS device 122. an indication of an RIS phase vector based on at least one of the resource grants. The network entity 104 may transmit 328, to the RIS device 122, the same RIS phase vector as described above.

[0063] Responsive to receiving 326 the resource grant, the UE 102 transmits 330 towards the RIS device 122, a narrowband radar signal corresponding to one or more of the plurality of narrowband beam directions.

[0064] The RIS device 122 reflects or redirects 332 the narrowband radar signal towards the object 116.

[0065] The UE 102 detects 334 the reflected portion of the narrowband radar signal that is reflected off the object 116.

[0066] The UE 102 receives 336 the reflection of the narrowband radar signal that is reflected off the object 116. The UE 102 receives the reflection of the narrowband radar signal, and the UE 102 then performs radar processing on the received reflection of the narrowband radar signal to determine radar signal measurement information which includes information about the blocked object 116.

[0067] While FIG. 3 shows the UE 102 as a radar-transmitter and the radar-receiver for radar sensing with the RIS device 122 as shown in FIGs. 1 and 2A. FIG. 4 describes another example scenario 400 in which the network entity 104 operates as a radartransmitter and the radar-receiver for radar sensing with the RIS device 122 as shown in FIG. 2B.

[0068] FIG. 4 shows example scenario 400 implemented by the network entity 104 depicted in FIG. 2B. The network entity 104 may correspond to a base station or a unit of a base station, such as the RU 106, the DU 108, the CU 110, etc. The procedures 301A, 301B. 301C, 302, 312, 328 of FIG. 4 are similar to procedures 301 A, 301B. 301C, 302, 312, 328 of FIG. 3. While the example scenario 400 illustrates a RIS device 122, other implementations may include an APD.

[0069] Referring to FIG. 4, the network entity 104 transmits 414 a wideband radar signal towards the RIS device 122.

[0070] The RIS redirects or reflects 416 the wideband radar signal towards the object 116.

[0071] The network entity' 104 receives 420 the reflected portion of the wideband radar signal that is reflected off the object 116.

[0072] Based on the reflection of the wideband radar signal, the network entity 104 detects 422 narrowband beam directions associated with an object detection. For example, as described above, the reflection of the wideband radar signal includes the beam squinting effect. The network entity 104 identifies a plurality' of narrowband beam directions, one of which is the narrowband beam direction that the network entity should use for the detection of the object 116. Therefore, the network entity 104 determines the proper narrowband beam direction to use for the object detection based on each of the plurality of narrowband beam directions (identified from the beam squinting).

[0073] The network entity 104 transmits 430 towards the RIS device 122, a narrowband radar signal corresponding to one or more of the plurality of narrowband beam directions.

[0074] The RIS device 122 redirects or reflects 432 the narrowband radar signal towards the object 116.

[0075] The network entity 104 receives 434 the reflected portion of the narrowband radar signal that is reflected off the object 116.

[0076] The network entity 104 detects 436, the reflection of the narrowband radar signal that is reflected off the object 116. The network entity 104 then performs radar processing on the received reflection of the narrowband radar signal to determine radar signal measurement information which includes information about the blocked object 116.

[0077] FIGs. 5-7 show methods for implementing one or more aspects of FIGs. 2A. 2B. 3, and 4. In particular, FIG. 5 shows an implementation by a UE 102 as a radartransmitter and as a radar-receiver of one or more aspects of FIGs. 2A and 3. FIG. 6 shows an implementation by a network entity 104 as a radar-transmitter, a radarreceiver, and a radar-assistor of one or more aspects of FIGs. 2B and 4. FIG. 7 shows an implementation by a RIS device 122 of one or more aspects of FIGs. 2A-2B, 3, and 4.

[0078] FIG. 5 is a flow diagram 500 depicting an example method of performing radar sensing with the RIS device 122. With reference to FIGs. 1-4 and 7, the method may be performed by the UE 102.

[0079] Referring to FIG. 5, in the method 500, the UE 102 optionally transmits 504, to the netw ork entity 104, a radar capability7message indicating a capability7of the UE for RIS radar processing. Referring to FIG. 2, for example, the UE 102 may transmit 304, to the network entity 104, a radar processing capability message that indicates radar capabilities supported by the UE for the radar sensing with the RIS devicel22.

[0080] The UE 102 receives 506, from the network entity7104, RIS beam squinting information. Referring to FIG. 3, for example, the UE 102 receives, from the netw ork entity 104, RIS beam squinting information.

[0081] The UE 102 transmits 508, to the network entity 104 based on the RIS beam squinting information, a first request message for a first resource grant to perform the wideband radar processing. Referring to FIG. 3, for example, the UE 102 transmits 308, to the network entity7104, a first request message for requesting a resource grant to perform wideband radar sensing with the RIS device 122.

[0082] The UE 102 receives 510, from the network entity' 104, first control signaling indicating the first resource grant for the transmitting the wideband radar signal. Referring to FIG. 3, for example, the UE 102 receives 310 a grant indicating resources for the wideband radar sensing.

[0083] The UE 102 transmits 514, towards the RIS device, wideband radar signal. Referring to FIG. 3, for example, the UE 102 transmits 314 tow ards the RIS device 122 a wideband radar signal using the granted resources.

[0084] The UE 102 receives 520 a first reflection of the wideband radar signal. Referring to FIG. 3, for example, the UE 102 receives 320 the reflection of the wideband radar signal that is reflected off the object 116.

[0085] The UE 102 transmits 524, to the network entity 104 based on the receiving the first reflection, a second request message for a second resource grant to perform the narrowband radar processing. Referring to FIG. 3, for example, the UE 102 transmits 324, to the network entity 104. a request message for a resource grant to perform the narrowband radar sensing.

[0086] The UE 102 receives 526, from the network entity 104, second control signaling indicating the second resource grant for the transmitting the narrowband radar signal. Referring to FIG. 3, for example, the UE 102 receives 326, from the network entity 104, control signaling indicating the resource grant for the transmitting the narrowband radar signal.

[0087] The UE 102 transmits 530, towards the RIS device, narrowband radar signal. Referring to FIG. 3, for example, the UE 102 transmits 330 towards the RIS device 122, a narrowband radar signal corresponding to one or more of the plurality of narrowband beam directions.

[0088] The UE 102 receives 534 a second reflection of the narrowband radar signal. Referring to FIG. 3, for example, the UE 102 detects 334, the reflection of the narrowband radar signal that is reflected off the object 116.

[0089] FIG. 5 describes a method from a UE-side for radar sensing, whereas FIG. 6 describes a method from a network entity-side for radar sensing.

[0090] FIG. 6 is a flow diagram depicting an example method, implemented in a network entity 104, of performing radar sensing. With reference to FIGs. 1-4 and 9, the method may be performed by one or more network entities 104. which may correspond to a base station or a unit of the base station, such as the RU 106. the DU 108, and / or the CU 1 10.

[0091] In embodiments, the network entity 104 transmits 601 A, to the RIS device 122, the wideband radar signal to sweep a RIS phase vector for beam squinting angles associated with the RIS phase vector. Referring to FIGs. 3-4, for example, the network entity 104 transmits 301 A, to the RIS device 122, a wideband radar signal to sweep a RIS phase vector.

[0092] The network entity 104 receives 601C, from the RIS device 122, the RIS beam squinting information. The RIS beam squinting information includes the beam squinting angles associated with the wideband radar signal. Referring to FIGs. 3-4, for example, the network entity 104, receives 301C, from the RIS device 122, RISbeam squinting information including the beam squinting angles associated with the reflection of the wideband radar signal.

[0093] The network entity 104 optionally receives 604, from the UE 102, a radar capability message indicating a capability of the UE for RIS radar processing. Referring to FIG. 3, for example, the network entity 104 may receive 304. from the UE 102, a radar processing capability’ message that indicates radar capabilities supported by the UE for the radar sensing with the RIS device 122.

[0094] The network entity 104 transmits 606, to the UE 102, RIS beam squinting information. Referring to FIG. 3, for example, the network entity 104 transmits 306. to the UE 102, RIS beam squinting information.

[0095] The network entity 104 receives 608, from the UE 102, based on the RIS beam squinting information, a first request message for a first resource grant to perform the wideband radar processing. Referring to FIG. 3, for example, the network entity 104 receives 308. from the UE 102, a first radar request message for requesting a radar resource grant to perform wideband radar sensing with the RIS device 122.

[0096] The network entity 104 transmits 610, to the UE 102, first control signaling indicating the first resource grant for the transmitting the wideband radar signal. Referring to FIG. 3, for example, the network entity 104 transmits 310 a grant indicating resources for RIS wideband radar processing.

[0097] The network entity 104 transmits 612, to the RIS device, an indication of an RIS phase vector based on at least one of the first resource grant or the second resource grant. Referring to FIG. 3. for example, the network entity 104 transmits 312, to the RIS device 122, the RIS phase vector.

[0098] The network entity’ 104 transmits 614, towards the RIS, wideband radar signal. Referring to FIG. 4, for example, the network entity 104 transmits 414 towards the RIS device 122 a wideband radar signal using the granted resources.

[0099] The network entity 104 receives 620 a first reflection of the wideband radar signal. Referring to FIG. 4, for example, the network entity 104 receives 420, from the object 116, the reflection of the wideband radar signal that is reflected off the object 116.

[0100] The network entity 104 receives 624, from the UE, based on the receiving the first reflection, a second request message for a second resource grant to perform the narrowband radar processing. Referring to FIG. 3, for example, the network entity 104 receives 324, from the UE 2, a request message for a resource grant to perform the narrowband radar sensing.

[0101] The network entity 104 transmits 626, to the UE. second control signaling indicating the second resource grant for transmission of the narrowband radar signal. Referring to FIG. 3, for example, the network entity 104 transmits 326, to the UE 102, control signaling indicating the resource grant for the transmitting the narrowband radar signal.

[0102] The network entity 104 transmits 630, towards the RIS device 122, a narrowband radar signal corresponding to one or more of the plurality' of narrowband beam directions. Referring to FIG. 3, for example, the network entity 104 transmits 330 towards the RIS device 122, a narrowband radar signal corresponding to one or more of the plurality of narrowband beam directions.

[0103] The network entity 104 receives 634 a second reflection of the narrowband radar signal. Referring to FIG. 3, for example, the network entity 104 detects the reflection of the narrowband radar signal that is reflected off the object 116.

[0104] FIG. 6 describes a method from a network entity-side for radar sensing, whereas FIG. 7 describes a method from a RIS device-side for radar sensing.

[0105] FIG. 7 is a flow diagram 700 depicting an example method, implemented in a RIS device, of performing radar sensing. With reference to FIGs. 1-4, the method may be performed by one or more RIS devices 122.

[0106] Referring to FIG. 7, the RIS device 122 receives 701 A, from anetwork entity 104, a wideband radar signal to sweep a RIS phase vector. Referring to FIG. 3, for example, the RIS device 122 receives from the network entity 104, a wideband radar signal to sweep a RIS phase vector.

[0107] The RIS device 122 measuring 701B a reflection of the wideband radar signal for beam squinting angles associated with the RIS phase vector. Referring to FIG. 3, for example, the RIS device 122 measures 301B a reflection of the wideband radar signal for beam squinting angles associated with the RIS phase vector.

[0108] The RIS device 122 transmits 701C, to the network entity 104, RIS beam squinting information including the beam squinting angles associated with the reflection of the wideband radar signal. Referring to FIG. 3, for example, the RIS device 122 transmits 301C RIS beam squinting information including the beam squinting angles associated with the reflection of the wideband radar signal.

[0109] The RIS device 122 receives 712, from the network entity' 104, an indication of the RIS phase vector associated with the wideband radar signal. Referring to FIG.3. for example, the RIS device 122 receives 312. from the network entity 104. the RIS phase vector.

[0110] A UE apparatus 802, as described in FIG. 8, may perform the method of flowchart 500 in FIG. 5. The one or more network entities 104, as described in FIG. 9, may perform the method of flowchart 600 in FIG. 6.

[0111] FIG. 8 is a diagram 800 illustrating an example of a hardware implementation for a UE apparatus 802. The UE apparatus 802 may be the UE 102, a component of the UE 102, or may implement UE functionality. The UE apparatus 802 may include an application processor 806, which may have on-chip memory 806’. In examples, the application processor 806 may be coupled to a secure digital (SD) card 808 and / or a display 810. The application processor 806 may also be coupled to a sensor(s) module 812, a power supply 814, an additional module of memory' 81 , a camera 818, and / or other related components. For example, the sensor(s) module 812 may control a barometric pressure sensor / altimeter, a motion sensor such as an inertial management unit (IMU), a gy roscope, accelerometer(s), a light detection and ranging (LIDAR) device, a radio-assisted detection and ranging (RADAR) device, a sound navigation and ranging (SONAR) device, a magnetometer, an audio device, and / or other technologies used for positioning.

[0112] The UE apparatus 802 may further include a wireless baseband processor 826, which may7be referred to as a modem. The wireless baseband processor 826 may7have on-chip memory' 826'. Along with, and similar to, the application processor 806, the wireless baseband processor 826 may also be coupled to the sensor(s) module 812, the power supply 814, the additional module of memory 816. the camera 818, and / or other related components. The wireless baseband processor 826 may be additionally coupled to one or more subscriber identity module (SIM) card(s) 820 and / or one or more transceivers 830 (e.g., wireless RF transceivers).

[0113] Within the one or more transceivers 830. the UE apparatus 802 may include a Bluetooth module 832, a WLAN module 834, an SPS module 836 (e g., GNSS module), and / or a cellular module 838. The Bluetooth module 832, the WLAN module 834, the SPS module 836, and the cellular module 838 may each include an on-chip transceiver (TRX). or in some cases, just a transmitter (TX) or just a receiver (RX). The Bluetooth module 832, the WLAN module 834, the SPS module 836, and the cellular module 838 may7each include dedicated antennas and / or utilize antennas 840 for communication with one or more other nodes. For example, the UE apparatus802 can communicate through the transceiver(s) 830 via the antennas 840 with another UE (e.g., sidelink communication) and / or with a network entity 104 (e g., uplink / downlink communication), where the network entity 104 may correspond to a base station or a unit of the base station, such as the RU 106, the DU 108, or the CU 110.

[0114] The wireless baseband processor 826 and the application processor 806 may each include a computer-readable medium / memory 826', 806', respectively. The additional module of memory 816 may also be considered a computer-readable medium / memory. Each computer-readable medium / memory’ 826', 806'. 816 may be non-transitory. The wireless baseband processor 826 and the application processor 806 may each be responsible for general processing, including execution of software stored on the computer-readable medium / memory’ 826', 806', 816. The software, when executed by the wireless baseband processor 826 / application processor 806, causes the wireless baseband processor 826 / application processor 806 to perform the various functions described herein. The computer-readable medium / memory may also be used for storing data that is manipulated by the wireless baseband processor 826 / application processor 806 when executing the software. The wireless baseband processor 826 I application processor 806 may be a component of the UE 102. The UE apparatus 802 may be a processor chip (e.g., modem and / or application) and include just the wireless baseband processor 826 and / or the application processor 806. In other examples, the UE apparatus 802 may be the entire UE 102 and include the additional modules of the apparatus 802.

[0115] As discussed in FIG. 1 and implemented with respect to FIG. 5. the UE R1S radar component 140 is configured to transmit, towards a reconfigurable intelligent surface, RIS, device 122, a wideband radar signal; receive a first reflection of the wideband radar signal, the first reflection indicating a plurality of narrowband beam directions associated with a first object detection; transmit towards the RIS device 122, a narrowband radar signal corresponding to one or more of the plurality of narrowband beam directions; and receive a second reflection of the narrow band radar signal, the second reflection being associated with a second object detection.

[0116] The UE RIS radar component 140 may be within the application processor 806 (e.g., at 140a), the wireless baseband processor 826 (e.g., at 140b), or both the application processor 806 and the wireless baseband processor 826. The UE RIS radar component 140a- 140b may be one or more hardware components specificallyconfigured to carry out the stated processes / algorithm, implemented by one or more processors configured to perform the stated processes / algorithm, stored within a computer-readable medium for implementation by the one or more processors, or a combination thereof.

[0117] FIG. 9 is a diagram 900 illustrating an example of a hardware implementation for one or more network entities 104. The one or more network entities 104 may be a base station, a component of a base station, or may implement base station functionality. The one or more network entities 104 may include, or may correspond to, at least one of the RU 106, the DU, 108, or the CU 110. The CU 110 may include a CU processor 946, which may have on-chip memory 946'. In some aspects, the CU 110 may further include an additional module of memory 956 and / or a communications interface 948, both of which may be coupled to the CU processor 946. The CU 110 can communicate with the DU 108 through a midhaul link 162, such as an F l interface between the communications interface 948 of the CU 110 and a communications interface 928 of the DU 108.

[0118] The DU 108 may include a DU processor 926, which may have on-chip memory7926'. In some aspects, the DU 108 may further include an additional module of memory 936 and / or the communications interface 928, both of which may be coupled to the DU processor 926. The DU 108 can communicate with the RU 106 through a fronthaul link 160 between the communications interface 928 of the DU 108 and a communications interface 908 of the RU 106.

[0119] The RU 106 may include an RU processor 906, which may have on-chip memory 906'. In some aspects, the RU 106 may further include an additional module of memory 916, the communications interface 908, and one or more transceivers 930, all of which may be coupled to the RU processor 906. The RU 106 may further include antennas 940, which may be coupled to the one or more transceivers 930, such that the RU 106 can communicate through the one or more transceivers 930 via the antennas 940 with the UE 102.

[0120] The on-chip memory7906', 926', 946' and the additional modules of memory 916, 936, 956 may each be considered a computer-readable medium I memory. Each computer-readable medium / memory may be non-transitory. Each of the processors 906, 926, 946 is responsible for general processing, including execution of software stored on the computer-readable medium / memory. The software, when executed by the corresponding processor(s) 906, 926, 946 causes the processor(s) 906, 926, 946to perform the various functions described herein. The computer-readable medium / memory may also be used for storing data that is manipulated by the processor(s) 906, 926, 946 when executing the software. In examples, the BS RIS radar component 150 may sit at any of the one or more network entities 104, such as at the CU 110; both the CU 110 and the DU 108; each of the CU 110, the DU 108. and the RU 106; the DU 108; both the DU 108 and the RU 106; or the RU 106.

[0121] As discussed in FIG. 1 and implemented with respect to FIG. 6, the BS RIS radar component 150 is configured to transmit, towards a reconfigurable intelligent surface, RIS, device 122, a wideband radar signal; receive a first reflection of the wideband radar signal, the first reflection indicating a plurality of narrowband beam directions associated with a first object detection; transmit towards the RIS device 122, a narrowband radar signal corresponding to one or more of the plurality of narrowband beam directions; and receive a second reflection of the narrowband radar signal, the second reflection being associated with a second object detection.

[0122] The BS RIS radar component 150 may be within one or more processors of the one or more network entities 104, such as the RU processor 906 (e.g., at 150a), the DU processor 926 (e.g., at 150b), and / or the CU processor 946 (e.g., at 150c). The BS RIS radar component 150a-150c may be one or more hardware components specifically configured to carry out the stated processes / algorithm, implemented by one or more processors 906, 926, 946 configured to perform the stated processes / algorithm, stored within a computer-readable medium for implementation by the one or more processors 906, 926, 946, or a combination thereof.

[0123] The specific order or hierarchy of blocks in the processes and flowcharts disclosed herein is an illustration of example approaches. Hence, the specific order or hierarchy of blocks in the processes and flowcharts may be rearranged. Some blocks may also be combined or deleted. Dashed lines may indicate optional elements of the diagrams. The accompanying method claims present elements of the various blocks in an example order, and are not limited to the specific order or hierarchy presented in the claims, processes, and flowcharts.

[0124] The detailed description set forth herein describes various configurations in connection with the drawings and does not represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough explanation of various concepts. However, these concepts may be practiced without these specific details.In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

[0125] Aspects of wireless communication systems, such as telecommunication systems, are presented with reference to various apparatuses and methods. These apparatuses and methods are described in the following detailed description and are illustrated in the accompanying drawings by various blocks, components, circuits, processes, call flows, systems, algorithms, etc. (collectively referred to as “elements”). These elements may be implemented using electronic hardware, computer software, or combinations thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

[0126] An element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems-on-chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other similar hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software, which may be referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, or any combination thereof.

[0127] If the functionality described herein is implemented in software, the functions may be stored on, or encoded as, one or more instructions or code on a computer-readable medium, such as a non-transitory computer-readable storage medium. Computer- readable media includes computer storage media and can include a random-access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of these types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructionsor data structures that can be accessed by a computer. Storage media may be any available media that can be accessed by a computer.

[0128] Aspects, implementations, and / or use cases described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, the aspects, implementations, and / or use cases may come about via integrated chip implementations and other non-module-component based devices, such as end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail / purchasing devices, medical devices, artificial intelligence (Al)-enabled devices, machine learning (ML)-enabled devices, etc. The aspects, implementations, and / or use cases may range from chip-level or modular components to non-modular or non-chip-level implementations, and further to aggregate, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more techniques described herein.

[0129] Devices incorporating the aspects and features described herein may also include additional components and features for the implementation and practice of the claimed and described aspects and features. For example, transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes, such as hardware components, antennas, RF-chains. power amplifiers, modulators, buffers, processor(s), interleavers, adders / summers, etc. Techniques described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, aggregated or disaggregated components, end-user devices, etc., of varying configurations.

[0130] The description herein is provided to enable a person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not limited to the aspects described herein, but are to be interpreted in view of the full scope of the present disclosure consistent with the language of the claims.

[0131] Reference to an element in the singular does not mean “one and only one’’ unless specifically stated, but rather “one or more.” Terms such as “if,” “when,” and “while” do not imply an immediate temporal relationship or reaction. That is, these phrases, e.g., “when,” do not imply an immediate action in response to or during the occurrence of an action, but simply imply that if a condition is met then an action will occur, but without requiring a specific or immediate time constraint for the action to occur. Theterms “may”, “might”, and “can”, as used in this disclosure, often carry certain connotations. For example, “may” refers to a permissible feature that may or may not occur, “might” refers to a feature that probably occurs, and “can” refers to a capability (e.g., capable of). The phrase “For example” often carries a similar connotation to “may” and. therefore, “may” is sometimes excluded from sentences that include “for example” or other similar phrases.

[0132] Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C” or “one or more of A, B, or C” include any combination of A, B, and / or C, such as A and B, A and C, B and C, or A and B and C, and may include multiples of A, multiples of B, and / or multiples of C, or may include A only, B only, or C only. Sets should be interpreted as a set of elements where the elements number one or more. Terms or articles such as “a”, “an”, and / or “the” may refer to one of an item, feature, element, etc., that the term or article precedes, or may refer to more than one of said item, feature, element, etc. that the term or article precedes. For example, the recitation “a widget” does not preclude reference to multiples of said widget, as “multiple widgets” necessarily includes “a widget”. Hence, the recitation “a widget” may be interpreted as “at least one widget” or, similarly, interpreted as “one or more widgets”.

[0133] Unless otherwise specifically indicated, ordinal terms such as “first” and “second” do not necessarily imply an order in time, sequence, numerical value, etc., but are used to distinguish between different instances of a term or phrase that follows each ordinal term.

[0134] Reference numbers, as used in the specification and figures, are sometimes cross- referenced among drawings to denote same or similar features. A feature that is exactly the same in multiple drawings may be labeled with the same reference number in the multiple drawings. A feature that is similar among the multiple drawings, but not exactly the same, may be labeled with reference numbers that have different leading numbers but have one or more of the same trailing numbers (e.g., 206, 306, 406, etc., may refer to similar features in the drawings). Hence, like numbers may refer to like actions.

[0135] Structural and functional equivalents to elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are encompassed by the claims. The words “module,” “mechanism,” “element,”“device,” and the like may not be a substitute for the word “means.” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for.” As used herein, the phrase “based on” shall not be construed as a reference to a closed set of information, one or more conditions, one or more factors, or the like. In other words, the phrase “based on A”, where “A” may be information, a condition, a factor, or the like, shall be construed as “based at least on A” unless specifically recited differently.

[0136] The following examples are illustrative only and may be combined with other examples or teachings described herein, without limitation.

[0137] Example 1 is a method of radar sensing at a wireless device, including transmitting, towards a reconfigurable intelligent surface, RIS. device, a wideband radar signal; receiving a first reflection of the wideband radar signal, the first reflection indicating a plurality of narrowband beam directions associated with a first object detection; transmitting, towards the RIS device, a narrowband radar signal corresponding to one or more of the plurality of narrowband beam directions; and receiving a second reflection of the narrowband radar signal, the second reflection being associated with a second object detection.

[0138] Example 2 may be combined with example 1 and further includes that the first object detection is based on a first location of an object and the second object detection is based on a second location of the object, the second location having a greater accuracy than the first location.

[0139] Example 3 may be combined with any of examples 1-2 and further includes that the wireless device is a user equipment. UE.

[0140] Example 4 may be combined with example 3 and further includes transmiting, to a network entity, a radar capability message indicating a capability of the UE for RIS radar processing, the RIS radar processing including wideband radar processing and narrowband radar processing.

[0141] Example 5 may be combined with any of examples 3-4 and further includes receiving, from the network entity, RIS beam squinting information; and transmiting, to the network entity based on the RIS beam squinting information, a first request message for a first resource grant to perform the wideband radar processing.

[0142] Example 6 may be combined with any of examples 3-5 and further includes receiving, from the network entity, first control signaling indicating the first resource grant for the transmiting the wideband radar signal.

[0143] Example 7 may be combined with any of examples 3-6 and further includes transmiting, to the network entity based on the receiving the first reflection, a second request message for a second resource grant to perform the narrowband radar processing.

[0144] Example 8 may be combined with any of examples 3-7 and further includes receiving, from the network entity, second control signaling indicating the second resource grant for the transmitting the narrowband radar signal.

[0145] Example 9 may be combined with any of examples 1-2 and further includes that the wireless device is a network entity.

[0146] Example 10 may be combined with example 9 and further includes receiving, from a user equipment, UE, a radar capability message indicating a capability of the UE for RIS radar processing, the RIS radar processing including wideband radar processing and narrowband radar processing.

[0147] Example 11 may be combined with any of examples 9-10 and further includes transmitting, to the UE, RIS beam squinting information; and receiving, from the UE based on the transmitting the RIS beam squinting information, a first request message for a first resource grant to perform the wideband radar processing.

[0148] Example 12 may be combined with example 11 and further includes that the transmitting the RIS beam squinting information is based on: transmitting, to the RIS device, the wideband radar signal to sweep a RIS phase vector for beam squinting angles associated with the RIS phase vector.

[0149] Example 13 may be combined with example 12 and further includes: receiving, from the RIS device, the RIS beam squinting information and further includes that the RIS beam squinting information includes the beam squinting angles associated with the wideband radar signal.

[0150] Example 14 may be combined with any of examples 9-13 and further includes transmitting, to the UE, first control signaling indicating the first resource grant for transmission of the w ideband radar signal.

[0151] Example 15 may be combined with any of examples 9-14 and further includes receiving, from the UE, a second request message for a second resource grant to perform the narrowband radar processing.

[0152] Example 16 may be combined with any of examples 9-15 and further includes transmitting, to the UE, second control signaling indicating the second resource grant for transmission of the narrowband radar signal.

[0153] Example 17 may be combined with any of examples 9-16 and further includes transmitting, to the RIS device, an indication of an RIS phase vector based on at least one of the first resource grant or the second resource grant.

[0154] Example 18 the method of any of examples 5-8 or 13-17 and further includes that tire RIS beam squinting information includes at least one of a beam squinting angle or beam widths as a function of RIS phase vectors.

[0155] Example 19 may be combined with any of examples 5-8 or 13-18 and further includes that the first request message includes a field indicating a phase vector map for mapping RIS phase vectors to a region of interest associated with the first object detection or the second object detection.

[0156] Example 20 may be combined with any of examples 6-8 or 14-19 and further includes that the first control signaling further indicates a conditional resource for transmission of the narrowband radar signal.

[0157] Example 21 may be combined with any of examples 7-8 or 15-20 and further includes that the second request message includes a field indicating at least one of: a plurality of narrowband radar signals including the narrowband radar signal; or a frequency range associated with the narrowband radar signal, the frequency range being based on the beam squinting information.

[0158] Example 22 may be combined with any of examples 8 or 16-21 and further includes that the first control signaling and the second control signaling indicate at least one of: first time and frequency resources for the wideband radar signal, second time and frequency resources for the narrowband radar signal, a first type of waveform of the wideband radar signal, or a second type of waveform of the narrowband radar signal.

[0159] Example 23 is a method of radar sensing at a reconfigurable intelligent surface. RIS, device, including receiving, from a network entity , a wideband radar signal to sweep a RIS phase vector; measuring a reflection of the wideband radar signal for beam squinting angles associated with the RIS phase vector; and transmitting, to the network entity, RIS beam squinting information including the beam squinting angles associated with the reflection of the wideband radar signal.

[0160] Example 24 may be combined with example 23 and further includes receiving, from the netw ork entity , an indication of the RIS phase vector associated with the wideband radar signal.

[0161] Example 25 may be combined with example 24 and further includes controlling an array of surface elements based on the indication of the RIS phase vector.

[0162] Example 26 is an apparatus for wireless communication comprising a memory, a transceiver, and a processor coupled to the memory and the transceiver, the apparatus being configured to implement is a method as in any of claims 1-25.

[0163] Example 27 is an apparatus for radar sensing, including a transceiver; a memory; and a processor coupled to the memory and the transceiver, the processor configured to: transmit, towards a reconfigurable intelligent surface, RIS, device, a wideband radar signal; receive a first reflection of the wideband radar signal, the first reflection indicating a plurality of narrowband beam directions associated with a first object detection; transmit, towards the RISdevice, a narrowband radar signal corresponding to one or more of the plurality of narrowband beam directions; and receive a second reflection of the narrowband radar signal, the second reflection being associated with a second object detection.

[0164] Example 28 may be combined with example 27 and further includes that the first object detection is based on a first location of an object and the second object detection is based on a second location of the object, the second location having a greater accuracy than the first location.

[0165] Example 29 may be combined with any of examples 27-28 and further includes that the apparatus is a user equipment, UE.

[0166] Example 30 may be combined with example 29 and further includes that the processor is further configured to: transmit, to a network entity, a radar capability message indicating a capability of the UE for RIS radar processing, the RIS radar processing including wideband radar processing and narrowband radar processing.

[0167] Example 31 may be combined with any of examples 29-30 and further includes that the processor is further configured to: receive, from the network entity, RIS beam squinting information; and transmit, to the network entity based on the RIS beam squinting information, a first request message for a first resource grant to perform the wideband radar processing.

[0168] Example 32 may be combined with any of examples 29-31 and further includes that the processor is further configured to: receive, from the network entity, first control signaling indicating the first resource grant for the transmitting the wideband radar signal.

[0169] Example 33 may be combined with any of examples 29-32 and further includes that the processor is configured to: transmit, to the network entity based on the receiving the first reflection, a second request message for a second resource grant to perform the narrowband radar processing.

[0170] Example 34 may be combined with any of examples 29-33 and further includes that the processor is further configured to: receive, from the network entity, second control signaling indicating the second resource grant for the transmitting the narrowband radar signal.

[0171] Example 35 may be combined with any of examples 27-28 and further includes that the apparatus is a network entity.

[0172] Example 36 may be combined with example 35 and further includes that the processor is further configured to: receive, from a user equipment. UE, a radar capability message indicating a capability of the UE for RIS radar processing, the RIS radar processing including wideband radar processing and narrowband radar processing.

[0173] Example 37 may be combined with any of examples 35-36 and further includes that the processor is further configured to: transmit, to the UE, RIS beam squinting information; andreceive, from the UE based on the transmitting the RIS beam squinting information, a first request message for a first resource grant to perform the wideband radar processing.

[0174] Example 38 may be combined with example 37 and further includes that the processor configured to transmit the RIS beam squinting information is based on the processor configured to: transmit, to the RIS device, the wideband radar signal to sweep a RIS phase vector for beam squinting angles associated with the RIS phase vector.

[0175] Example 39 may be combined with example 38 and further includes that the processor is further configured to: receive, from the RIS device, the RIS beam squinting information and further includes that the RIS beam squinting information includes the beam squinting angles associated with the wideband radar signal.

[0176] Example 40 may be combined with any of examples 35-39 and further includes that the processor is further configured to: transmit, to the UE, first control signaling indicating the first resource grant for transmission of the wideband radar signal.

[0177] Example 41 may be combined with any of examples 35-40 and further includes that the processor is further configured to: receive, from the UE. a second request message for a second resource grant to perform the narrowband radar processing.

[0178] Example 42 may be combined with any of examples 35-41 and further includes that the processor is further configured to: transmit, to the UE. second control signaling indicating the second resource grant for transmission of the narrowband radar signal.

[0179] Example 43 may be combined with any of examples 35-42 and further includes that the processor is further configured to: transmit, to the RIS device, an indication of an RIS phase vector based on at least one of the first resource grant or the second resource grant.

[0180] Example 44 may be combined with any of examples 31-34 or 39-43 and further includes that the RIS beam squinting information includes at least one of a beam squinting angle or beam widths as a function of RIS phase vectors.

[0181] Example 45 may be combined with any of examples 31-34 or 39-44 and further includes that the first request message includes a field indicating a phase vector map for mapping RIS phase vectors to a region of interest associated with the first object detection or the second object detection.

[0182] Example 46 may be combined with any of examples 32-34 or 40-45 and further includes that the first control signaling further indicates a conditional resource for transmission of the narrowband radar signal.

[0183] Example 47 may be combined with any of examples 33-34 or 41-46 and further includes that the second request message includes a field indicating at least one of: a plurality of narrowband radar signals including the narrowband radar signal; or a frequency rangeassociated with the narrowband radar signal, the frequency range being based on the beam squinting information.

[0184] Example 48 may be combined with any of examples 34 or 42-47 and further includes that the first control signaling and the second control signaling indicate at least one of: first time and frequency resources for the wideband radar signal, second time and frequency resources for the narrowband radar signal, a first type of waveform of the wideband radar signal, or a second type of waveform of the narrowband radar signal.

[0185] Example 49 is a reconfigurable intelligent surface. RIS, device, including a transceiver; a memory; and a processor coupled to the emory and the transceiver and further includes that the processor is configured to: receive, from a netw ork entity, a wideband radar signal to sweep a RIS phase vector; measure a reflection of the wideband radar signal for beam squinting angles associated with the RIS phase vector; and transmit, to the network entity, RIS beam squinting information including the beam squinting angles associated with the reflection of the wideband radar signal.

[0186] Example 50 may be combined with example 49 and further includes that the processor is further configured to: receive, from the network entity, an indication of the RIS phase vector associated with the wideband radar signal.

[0187] Example 51 may be combined with example 50 and further includes an array of surface elements coupled to the processor and further includes that the processor is further configured to: control the array of surface elements based on the indication of the RIS phase vector.

Claims

CLAIMSWHAT IS CLAIMED IS:

1. A method of radar sensing at a wireless device, comprising: transmitting (314, 414), towards a reconfigurable intelligent surface, RIS, device (122), a wideband radar signal; receiving (320, 420) a first reflection of the wideband radar signal, the first reflection indicating a plurality of narrowband beam directions associated with a first object detection; transmitting (330, 430), towards the RIS device (122), a narrow-band radar signal corresponding to one or more of the plurality of narrowband beam directions; and receiving (334, 434) a second reflection of the narrowband radar signal, the second reflection being associated with a second object detection.

2. The method of claim 1, wherein the first object detection is based on a first location of an object and the second object detection is based on a second location of the object, the second location having a greater accuracy than the first location.

3. The method of any of claims 1-2. wherein the wireless device is a user equipment. UE, (102).

4. The method of claim 3, further comprising: transmitting (308). to a network entity (104) based on RIS beam squinting information, a first request message for a first resource grant to perform the wideband radar processing; and receiving (310), from the network entity (104), first control signaling indicating the first resource grant for the transmitting the wideband radar signal.

5. The method of any of claims 3-4, further comprising:transmitting (324). to the network entity (104) based on the receiving (320) the first reflection, a second request message for a second resource grant to perform a narrowband radar processing; and receiving (326), from the network entity (104). second control signaling indicating the second resource grant for the transmitting the narrowband radar signal.

6. The method of any of claims 1-2, wherein the wireless device is a network entity (104).

7. The method of claim 6, further comprising: transmitting (301 A), to the RIS device (122), the wideband radar signal to sweep a RIS phase vector for beam squinting angles associated with the RIS phase vector.

8. The method of any of claims 6-7, further comprising: receiving (324), from a user equipment, UE, a second request message for a second resource grant to perform a narrowband radar processing; and transmitting (326). to the UE, second control signaling indicating the second resource grant for transmission of the narrowband radar signal.

9. The method of any of claim 4-5 or 8, w herein the RIS beam squinting information includes at least one of a beam squinting angle or beam widths as a function of RIS phase vectors.

10. The method of any of claims 4-5 or 8-9, wherein the first request message includes a field indicating a phase vector map for mapping RIS phase vectors to a region of interest associated with the first object detection or the second object detection.

11. The method of any of claims 4-5 or 8-10, w herein the first control signaling further indicates a conditional resource for transmission of the narrow band radar signal.

12. The method of any of claims 4-5 or 8-11, wherein the second request message includes a field indicating at least one of: a plurality of narrowband radar signals including the narrowband radar signal; or a frequency range associated with the narrowband radar signal, the frequency range being based on the beam squinting information.

13. A method of radar sensing at a reconfigurable intelligent surface, RIS, device (122), comprising: receiving (301A), from a network entity (104), a wideband radar signal to sweep a RIS phase vector; measuring (301B) a reflection of the wideband radar signal for beam squinting angles associated with the RIS phase vector; and transmitting (301C), to the network entity (104), RIS beam squinting information including the beam squinting angles associated with the reflection of the wideband radar signal.

14. The method of claim 13, further comprising: receiving (312, 388), from the network entity (104), an indication of the RIS phase vector associated with the wideband radar signal; and controlling an array of surface elements based on the indication of the RIS phase vector.

15. An apparatus for wireless communication comprising a memory, a transceiver, and a processor coupled to the memory and the transceiver, the apparatus being configured to implement a method as in any of claims 1-14.

Images