Patent Publication Number: US-2022221553-A1

Title: Interference relocation in radar applications to mitigate inter-radar interference

Description:
BACKGROUND 
     Technical Field 
     The present disclosure relates generally to radar devices, and more particularly, to radar devices that may communicate with other radar devices. 
     Introduction 
     For radar devices, such as frequency modulated continuous wave (FMCW) radar devices, multiple radar sources may lead to interference. Conventional radar waveforms, such as FMCW, may be indistinguishable from various source(s). Such limitations for radar devices may be problematic for various applications that rely on radar devices for safety features. For example, Modern motor vehicles are increasingly incorporating technology that helps drivers, such as lane departure warning (LDW), forward collision warning FCW, among other things. Such technologies may utilize radar devices. Moreover, radar devices are also important for facilitating automated driving systems (ADS). There exists a need for further improvements in radar technology to facilitate these applications. 
     SUMMARY 
     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, and is intended to neither identify key or critical elements of all aspects nor delineate 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. 
     In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus of a first radar device are provided. The first radar device may detect an interfering radar signal from a second radar device that interferes with measurement of a return of a radar signal from the first radar device. The first radar device may perform a timing adjustment action in response to detecting the interfering radar signal from the second radar device. 
     In another aspect of the disclosure, a method, a computer-readable medium, and an apparatus of a first radar device are provided. The first radar device may receive a timing adjustment request from a second radar device. The first radar device may adjust a transmission timing of a radar signal in response to the timing adjustment request from the second radar device. 
     To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram illustrating an example of a wireless communications system and an access network. 
         FIG. 2  illustrates an example slot structure for wireless communication. 
         FIG. 3  is a diagram illustrating an example of a base station and user equipment (UE) in communication with a radar module in an access network. 
         FIG. 4  illustrates example interference for radar devices. 
         FIG. 5  illustrates an example FMCW. 
         FIGS. 6A and 6B  illustrate an example of interference causing a ghost target. 
         FIGS. 7A-7D  illustrate examples of radar operations in accordance with various aspects of the present disclosure. 
         FIG. 8  is a flowchart of a method of radar operation in accordance with various aspects of the present disclosure. 
         FIG. 9  is a flowchart of a method of radar operation in accordance with various aspects of the present disclosure. 
         FIG. 10  is a diagram illustrating an example of a hardware implementation for an example apparatus in accordance with various aspects of the present disclosure. 
         FIG. 11  is a diagram illustrating an example of a hardware implementation for an example apparatus in accordance with various aspects of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to 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 understanding of various concepts. However, it will be apparent to those skilled in the art that 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. 
     Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as “elements”). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. 
     By way of example, 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 a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. 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, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. 
     Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise 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 the aforementioned types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer. 
     A radar may be incorporated in equipment, such as a vehicle, for performing collision avoidance and other related techniques. Radar measurements may also be used for non-vehicular applications. The radar may be configured to transmit a radar signal/pulse and receive a return signal based on a reflection of the radar signal from an object. The radar device may determine the time delay between transmission of the radar signal and reception of the return signal in order to determine a distance between the radar and the object from which the return signal is reflected. Radar signal sensing may 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 may 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 may be employed to acquire contextual information, e.g., location detection, tracking, determining directions, range estimation, etc. Radar signal sensing may be employed to image an environment, e.g., to provide a 3-dimensional (3D) map for virtual reality (VR) applications. Radar signal sensing may be employed to provide high resolution localization, e.g., for industrial Internet-of-things (IIoT) applications. In some examples, the radar device may provide consumer level radar with advanced detection capabilities. Radar signal sensing may provide touchless or device free interaction with a device or system. For example, a wireless device may detect user gestures to trigger an operation at the wireless device. 
     Radar transmissions from different radar devices (e.g., devices equipped with radars) may lead to inter-radar interference when the radar devices are transmitting signals simultaneously, partially overlapping in time, or close in time within a given area. Radar signals may be signatureless, and a radar device may not be able to distinguish between the reflections of its radar pulses and interferences or reflections of radar pulses that originate from other radar devices. Thus, when multiple radar devices are in proximity of each other, the radar transmissions from different radar devices may interfere with each other. The interference, the radar pulse from another device, and/or a reflected radar pulse from other radar devices may appear as a false target to a radar, causing the radar signal device to be unable to identify the target or to obtain correct information about the target. 
     Aspects presented herein enable a radar device to perform adjustments or to communicate with an interfering radar device in order to reduce interference between radar devices. 
       FIG. 1  is a diagram  100  illustrating an example of a wireless communications system and an access network in which base stations  102  or  180  may wirelessly communicate with user equipments (UEs)  104 . Some wireless devices may perform radar signal sensing. For example, a radar device  103  may transmit a wireless signal  105  and use information about the signal to image an environment or determine information about a target  107  based on range, doppler, and/or angle information determined from the wireless signal. The signal may include a defined waveform, such as a frequency modulated continuous wave (FMCW) or a pulse or chirp waveform. 
     In some examples, a radar device  103 , or a radar component  198 , may transmit a radar signal  105  to determine information about a target or an environment. In some examples, a UE  104  may include a radar component  198  or may be associated with a radar component  198  (that may be incorporated in or in communication with the UE  104 ) configured to transmit a radar signal  105  and to perform measurements and/or detect targets  107  based on a return, or reflection, of the radar signal  105  from the target  107 . The radar component  198  may be considered a radar device, or the UE  104  that comprises the radar component  198  may be considered a radar device. The UE  104  may be associated with and in communication with a radar module, such as an FMCW radar. In some aspects, the UE  104  may be a radar device that is mounted on a vehicle. The radar component  198  may include a radar adjustment component  199  that is configured to detect an interfering radar signal from a different radar device  103  that interferes with measurement of a return of a radar signal from the radar component  198  and to perform a timing adjustment action in response to detecting the interfering radar signal from the other radar device  103 . In some aspects, the radar adjustment component  199  may be configured to adjust a timing of the radar signal  105  on a per chirp or per frame basis. In other aspects, the radar adjustment component  199  may be configured to transmit a request/indication to the other radar device  103  to adjust the timing of the interfering radar signal. In some aspects, the radar adjustment component  199  may be configured to receive a timing adjustment request from a second radar device and adjust a transmission timing of a radar signal  105  in response to the timing adjustment request from the second radar device. As illustrated, the radar device  103  may similarly include a radar adjustment component  199 . 
     In some examples, radar devices  103 , or a wireless device having a radar component  198 , may exchange wireless communication. In some examples, the devices may exchange communication over a D2D link  158 , such as based on sidelink. 
     The wireless communications system (also referred to as a wireless wide area network (WWAN)) includes base stations  102 , UEs  104 , an Evolved Packet Core (EPC)  160 , and another core network  190  (e.g., a 5G Core (5GC)). The base stations  102  may include macrocells (high power cellular base station) and/or small cells (low power cellular base station). The macrocells include base stations. The small cells include femtocells, picocells, and microcells. 
     The base stations  102  configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) may interface with the EPC  160  through first backhaul links  132  (e.g., S1 interface). The base stations  102  configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN)) may interface with core network  190  through second backhaul links  184 . In addition to other functions, the base stations  102  may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations  102  may communicate directly or indirectly (e.g., through the EPC  160  or core network  190 ) with each other over third backhaul links  134  (e.g., X2 interface). The first backhaul links  132 , the second backhaul links  184 , and the third backhaul links  134  may be wired or wireless. 
     The base stations  102  may wirelessly communicate with the UEs  104 . Each of the base stations  102  may provide communication coverage for a respective geographic coverage area  110 . There may be overlapping geographic coverage areas  110 . For example, the small cell  102 ′ may have a coverage area  110 ′ that overlaps the coverage area  110  of one or more macro base stations  102 . A network that includes both small cell and macrocells may be known as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs), which may provide service to a restricted group known as a closed subscriber group (CSG). The communication links  120  between the base stations  102  and the UEs  104  may include uplink (UL) (also referred to as reverse link) transmissions from a UE  104  to a base station  102  and/or downlink (DL) (also referred to as forward link) transmissions from a base station  102  to a UE  104 . The communication links  120  may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The base stations  102 /UEs  104  may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL than for UL). The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell). 
     Certain UEs  104  may communicate with each other using device-to-device (D2D) communication link  158 . The D2D communication link  158  may use the DL/UL WWAN spectrum. The D2D communication link  158  may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). D2D communication may be through a variety of wireless D2D communications systems, such as for example, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR. 
     The wireless communications system may further include a Wi-Fi access point (AP)  150  in communication with Wi-Fi stations (STAs)  152  via communication links  154 , e.g., in a 5 GHz unlicensed frequency spectrum or the like. When communicating in an unlicensed frequency spectrum, the STAs  152 /AP  150  may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available. 
     The small cell  102 ′ may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell  102 ′ may employ NR and use the same unlicensed frequency spectrum (e.g., 5 GHz, or the like) as used by the Wi-Fi AP  150 . The small cell  102 ′, employing NR in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network. 
     The electromagnetic spectrum is often subdivided, based on frequency/wavelength, into various classes, bands, channels, etc. In 5G NR, two initial operating bands have been identified as frequency range designations FR 1  (410 MHz-7.125 GHz) and FR 2  (24.25 GHz-52.6 GHz). The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “sub-6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referred to (interchangeably) as a “millimeter wave” band in documents and articles, despite being different from the extremely high frequency (EHF) band (30 GHz-300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band. 
     With the above aspects in mind, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like if used herein may broadly represent frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like if used herein may broadly represent frequencies that may include mid-band frequencies, may be within FR2, or may be within the EHF band. 
     A base station  102 , whether a small cell  102 ′ or a large cell (e.g., macro base station), may include and/or be referred to as an eNB, gNodeB (gNB), or another type of base station. Some base stations, such as gNB  180  may operate in a traditional sub 6 GHz spectrum, in millimeter wave frequencies, and/or near millimeter wave frequencies in communication with the UE  104 . When the gNB  180  operates in millimeter wave or near millimeter wave frequencies, the gNB  180  may be referred to as a millimeter wave base station. The millimeter wave base station  180  may utilize beamforming  182  with the UE  104  to compensate for the path loss and short range. The base station  180  and the UE  104  may each include a plurality of antennas, such as antenna elements, antenna panels, and/or antenna arrays to facilitate the beamforming. 
     The base station  180  may transmit a beamformed signal to the UE  104  in one or more transmit directions  182 ′. The UE  104  may receive the beamformed signal from the base station  180  in one or more receive directions  182 ″. The UE  104  may also transmit a beamformed signal to the base station  180  in one or more transmit directions. The base station  180  may receive the beamformed signal from the UE  104  in one or more receive directions. The base station  180 /UE  104  may perform beam training to determine the best receive and transmit directions for each of the base station  180 /UE  104 . The transmit and receive directions for the base station  180  may or may not be the same. The transmit and receive directions for the UE  104  may or may not be the same. 
     The EPC  160  may include a Mobility Management Entity (MME)  162 , other MMEs  164 , a Serving Gateway  166 , a Multimedia Broadcast Multicast Service (MBMS) Gateway  168 , a Broadcast Multicast Service Center (BM-SC)  170 , and a Packet Data Network (PDN) Gateway  172 . The MME  162  may be in communication with a Home Subscriber Server (HSS)  174 . The MME  162  is the control node that processes the signaling between the UEs  104  and the EPC  160 . Generally, the MME  162  provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway  166 , which itself is connected to the PDN Gateway  172 . The PDN Gateway  172  provides UE IP address allocation as well as other functions. The PDN Gateway  172  and the BM-SC  170  are connected to the IP Services  176 . The IP Services  176  may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service, and/or other IP services. The BM-SC  170  may provide functions for MBMS user service provisioning and delivery. The BM-SC  170  may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway  168  may be used to distribute MBMS traffic to the base stations  102  belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information. 
     The core network  190  may include an Access and Mobility Management Function (AMF)  192 , other AMFs  193 , a Session Management Function (SMF)  194 , and a User Plane Function (UPF)  195 . The AMF  192  may be in communication with a Unified Data Management (UDM)  196 . The AMF  192  is the control node that processes the signaling between the UEs  104  and the core network  190 . Generally, the AMF  192  provides QoS flow and session management. All user Internet protocol (IP) packets are transferred through the UPF  195 . The UPF  195  provides UE IP address allocation as well as other functions. The UPF  195  is connected to the IP Services  197 . The IP Services  197  may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a Packet Switch (PS) Streaming (PSS) Service, and/or other IP services. 
     The base station may include and/or be referred to as a gNB, Node B, 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 transmit reception point (TRP), or some other suitable terminology. The base station  102  provides an access point to the EPC  160  or core network  190  for a UE  104 . Examples of UEs  104  include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, a display, or any other similar functioning device. Some of the UEs  104  may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc.). The UE  104  may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. 
       FIG. 2  includes diagrams  200  and  210  illustrating example aspects of slot structures that may be used for sidelink communication (e.g., between UEs  104 , RSU  107 , etc.). The slot structure may be within a 5G/NR frame structure in some examples. In other examples, the slot structure may be within an LTE frame structure. Although the following description may be focused on 5G NR, the concepts described herein may be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies. The example slot structure in  FIG. 2  is merely one example, and other sidelink communication may have a different frame structure and/or different channels for sidelink communication. A frame (10 ms) may be divided into 10 equally sized subframes (1 ms). Each subframe may include one or more time slots. Subframes may also include mini-slots, which may include 7, 4, or 2 symbols. Each slot may include 7 or 14 symbols, depending on the slot configuration. For slot configuration 0, each slot may include 14 symbols, and for slot configuration 1, each slot may include 7 symbols. Diagram  200  illustrates a single resource block of a single slot transmission, e.g., which may correspond to a 0.5 ms transmission time interval (TTI). A physical sidelink control channel may be configured to occupy multiple physical resource blocks (PRBs), e.g., 10, 12, 15, 20, or 25 PRBs. The PSCCH may be limited to a single sub-channel. A PSCCH duration may be configured to be 2 symbols or 3 symbols, for example. A sub-channel may comprise 10, 15, 20, 25, 50, 75, or 100 PRBs, for example. The resources for a sidelink transmission may be selected from a resource pool including one or more subchannels. As a non-limiting example, the resource pool may include between 1-27 subchannels. A PSCCH size may be established for a resource pool, e.g., as between 10-100% of one subchannel for a duration of 2 symbols or 3 symbols. The diagram  210  in  FIG. 2  illustrates an example in which the PSCCH occupies about 50% of a subchannel, as one example to illustrate the concept of PSCCH occupying a portion of a subchannel. The physical sidelink shared channel (PSSCH) occupies at least one subchannel. The PSCCH may include a first portion of sidelink control information (SCI), and the PSSCH may include a second portion of SCI in some examples. 
     A resource grid may be used to represent the frame structure. Each time slot may include a resource block (RB) (also referred to as physical RBs (PRBs)) that extends 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme. As illustrated in  FIG. 2 , some of the REs may comprise control information in PSCCH and some Res may comprise demodulation RS (DMRS). At least one symbol may be used for feedback.  FIG. 2  illustrates examples with two symbols for a physical sidelink feedback channel (PSFCH) with adjacent gap symbols. A symbol prior to and/or after the feedback may be used for turnaround between reception of data and transmission of the feedback. The gap enables a device to switch from operating as a transmitting device to prepare to operate as a receiving device, e.g., in the following slot. Data may be transmitted in the remaining REs, as illustrated. The data may comprise the data message described herein. The position of any of the data, DMRS, SCI, feedback, gap symbols, and/or LBT symbols may be different than the example illustrated in  FIG. 2 . Multiple slots may be aggregated together in some examples. 
       FIG. 3  is a block diagram of a first wireless device  310  having components for wireless transmission. The wireless device  310  may be a radar device configured to perform the aspects presented herein. The term radar device may be used to refer to a device that has the capability to transmit and receive a radar signal in order to determine information about surrounding objects, the environment about the device, etc. In some examples, the wireless device  310  may have the capability to communicate with another wireless device  350 , e.g., in addition to the radar transmission/reception, such as described in connection with  FIG. 1 . The wireless device  310  may include one or more antennas  320  may include a transmitter/receiver  318  with a corresponding transmit processor  316  and receive processor  370  that are configured to perform radar transmission and measurement, such as described in connection with  FIG. 1 . The one or more antenna  320 , transmitter/receiver  318 , transmit processor  316 , and receive processor  370  may transmit a radar signal and receive reflections of the radar signal. The controller/processor  375  may determine radar information about a target based on the received signal. 
     In some examples, the wireless device  310  may be capable of wireless communication in addition to radar transmission/detection. Thus,  FIG. 3  may also be a block diagram  300  of a first wireless device  310  in communication with a second wireless device  350  based on sidelink. In some examples, the devices  310  and  350  may communicate based on V2X or other D2D communication. The communication may be based on sidelink using a PC5 interface. The devices  310  and the  350  may comprise a UE, an RSU, a base station, etc. Packets may be provided to a controller/processor  375  that implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. 
     The transmit (TX) processor  316  and the receive (RX) processor  370  implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The TX processor  316  handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator  374  may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the device  350 . Each spatial stream may then be provided to a different antenna  320  via a separate transmitter  318 TX. Each transmitter  318 TX may modulate an RF carrier with a respective spatial stream for transmission. 
     At the device  350 , each receiver  354  RX receives a signal through its respective antenna  352 . Each receiver  354  RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor  356 . The TX processor  368  and the RX processor  356  implement layer 1 functionality associated with various signal processing functions. The RX processor  356  may perform spatial processing on the information to recover any spatial streams destined for the device  350 . If multiple spatial streams are destined for the device  350 , they may be combined by the RX processor  356  into a single OFDM symbol stream. The RX processor  356  then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by device  310 . These soft decisions may be based on channel estimates computed by the channel estimator  358 . The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by device  310  on the physical channel. The data and control signals are then provided to the controller/processor  359 , which implements layer 3 and layer 2 functionality. 
     The controller/processor  359  can be associated with a memory  360  that stores program codes and data. The memory  360  may be referred to as a computer-readable medium. The controller/processor  359  may provide demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing. The controller/processor  359  is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations. 
     Similar to the functionality described in connection with the transmission by device  310 , the controller/processor  359  may provide RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression/decompression, and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization. 
     Channel estimates derived by a channel estimator  358  from a reference signal or feedback transmitted by device  310  may be used by the TX processor  368  to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor  368  may be provided to different antenna  352  via separate transmitters  354  TX. Each transmitter  354  TX may modulate an RF carrier with a respective spatial stream for transmission. 
     The transmission is processed at the device  310  in a manner similar to that described in connection with the receiver function at the device  350 . Each receiver  318 RX receives a signal through its respective antenna  320 . Each receiver  318 RX recovers information modulated onto an RF carrier and provides the information to a RX processor  370 . 
     The controller/processor  375  can be associated with a memory  376  that stores program codes and data. The memory  376  may be referred to as a computer-readable medium. The controller/processor  375  provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing. The controller/processor  375  is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations. 
     The controller/processor  375  and/or  359  may be further in communication with and may control the operations of a radar module  362 , which may also be referred to as a radar component, such as the radar component  198  in  FIG. 1 . The wireless devices  310  and  350  may be referred to as a radar device in some examples. In other examples, the radar module  362  may be referred to as a radar device. 
     At least one of the TX processor  368 , the RX processor  356 , the radar module  362 , and the controller/processor  359  may be configured to perform aspects in connection with the radar adjustment component  199  of  FIG. 1 . 
       FIG. 4  illustrates example diagram  400  showing interference between radar devices.  FIG. 4  illustrates an example application of a radar component in a vehicle setting. Although the aspects are described for a radar component associated with a vehicle in order to explain the concept, the aspects may similarly be applied to a radar device that is not associated with a vehicle or that is applied on a non-vehicular setting. As shown by diagram  400  of  FIG. 4 , radar devices  402  and  406  may be associated with a vehicle for safety purposes (e.g., to avoid collisions), to monitor an environment, etc. One or more of the vehicles may transmit a radar signal and measure the reflected signal to detect a distance between other objects such as vehicles, pedestrians, road features, structures, etc. Although the actions are described as being performed by the vehicle, in some examples, the action may be performed by a radar device associated with a vehicle. Signals from different radar sources may lead to interference (e.g., inter-radar interference) e.g., if the radar signals are simultaneous, overlapping in time, or close in time. For example, the radar device  406  may transmit a radar signal  405 , and may use the reflection to detect a target  404 , other vehicles (e.g., radar device  402 ), the surrounding environment, etc. The radar device  402  may similarly transmit a radar signal  403 . The radar component of radar device  406  may receive the radar signal  403  as interference to the reflection of its own radar signal  405 . For example, as the radar signal (e.g., waveform) transmitted by radar devices  402  or  406  may be signatureless, the radar device  406  may not be able to distinguish between reflected radar pulses of its own radar signal  405  and other radar signals from other radar devices, such as the radar signal  403  or a reflection of the radar signal  403  from another radar device. In other words, radar waveforms, such as the frequency modulated continuous wave (FMCW), may be indistinguishable to a radar when they are coming from various sources. Thus, when more radar devices are in proximity with each other, they may start to interfere each other. The interference or the reflected radar pulse from other radar(s) may appear as a false target to a radar, or they may cause the radar to obtain incorrect information about the target (e.g., inaccurate distance, time offset, transmission power, etc.). Multiple radar sources may lead to significant interference. The radar signals from each radar device that may be high power may appear as a false target at a distance (e.g., half distance with a timing offset) with high power for the other radar device. 
       FIG. 5  illustrates example FMCW diagram  500  that illustrates a waveform for a radar signal  502  and a return signal  504 , e.g., a reflection of the radar signal  502 . As illustrated in  FIG. 5 , an FMCW radar may transmit chirps sweeping in frequency and receive the same chirps after delay (after reflection). The signals  502  and  504  may be associated with an FMCW waveform utilized by the radar for frequency sweeping. The radar device may detect a target object by transmitting a chirp signal (which may also be referred to as a pulse signal), where the chirp signal may have a frequency that varies linearly (e.g., frequency sweeping) over a fixed period of time (e.g., sweep time) by a modulating signal. For example, as shown by diagram  500 , a transmitted chirp may have a starting frequency. Then the frequency is gradually (e.g., linearly) increased on a sinusoid until it reaches an upper frequency of the sinusoid, and then the frequency of the signal returns to the starting frequency and another chirp may be transmitted in the same way. In other words, each chirp (or radar pulse) may include an increase in the frequency (e.g., linearly) and a drop in the frequency, such that the radar device may transmit chirps sweeping in frequency. The radar signal  502  may correspond to an instantaneous frequency that increases from zero to a higher frequency and subsequently decreases from the higher frequency to zero based on a sinusoidal operation. Each sweep up and down may correspond to an individual pulse or chirp of the FMCW. A chirp time may be indicated by T c  and a sweeping up time may be indicated by T up . For instance, the frequency may sweep up from 77 GHz to 78 GHz to provide a sweeping bandwidth of 1 GHz. A time period that elapses for the sweeping up of the 1 GHz of bandwidth may correspond to Tu p . After the radar sweeps up to 78 GHz, an additional/non-zero length of time may elapse for the radar to sweep down and return to 77 GHz. The additional/non-zero length of time may correspond to T down . Thus, T up +T down  may equal T c  (e.g., the duration of the chirp/pulse). In examples, the radar may be configured based on certain T c  parameters. 
     The radar may receive a series of chirps via the return signal  504  that match the transmitted signal  502 , albeit delayed based on a location of an object from which the return signal is reflected. As a distance between the radar and the object increases, the corresponding delay may become larger. The distance to the object may be determined based on determining the delay. For example, rather than directly measuring a time of the delay, a frequency delta between the transmitted signal  502  and the return signal  504  may be determined, where the frequency delta may be proportional to the delay. The range of the object may be further determined based on the delay being proportional to the range. The frequency delta may be associated with a range spectrum and a beat frequency (F b ) determined based on a Fast Fourier Transform (FFT). The beat frequency may correspond to a mixed output of the transmitted signal  502  and the return signal  504 . A slope for sweeping up the frequency may be defined (e.g., 1 GHz per T up  seconds), such that a rate at which the slope changes may correspond to a beta (β) parameter. 
     The parameters of the transmitted signal  502  and the return signal  504  may be indicative of a maximum (e.g., theoretical) detectable range of an FMCW receiver of the radar. For longer range radars, 100-300 m may be the maximum detectable range. The parameters may also be indicative of a maximum detectable speed/velocity (e.g., 30-40 m/s). For example, based on multiple received chirps, the velocity of the object may be determined based on a Doppler spectrum and a direction of the object may be determined based on a direction of arrival (DoA) spectrum. In examples, outputs such as x(t)=e jβt{circumflex over ( )}2 ; y(t)=x(t−τ)=e jβ(t−τ){circumflex over ( )}2 ; and/or y(t)x*(t)=e −j2πβτt e jβτ{circumflex over ( )}2  may be determined based on the parameters of the FMCW waveform, where x corresponds to a transmitted chirp signal, y corresponds to a received chirp signal, t corresponds to time, j corresponds to √{square root over (−1)}, and τ corresponds to a delay between a transmitted chirp and a received chirp. That is, three different frequency analyses may be performed to determine range, velocity, and/or direction. There may be a delay proportional to range. There may be mixer output beat frequency. An FMCW receiver (e.g., incorporated in a radar) may operate in a range spectrum and may identify beat frequency/range. With multiple chirps, the FMCW receiver may identify target velocity based on Doppler spectrum and may identify target direction based on the direction of arrival (DoA) spectrum. 
       FIGS. 6A and 6B  illustrate examples  600  and  650  illustrating an interference that is causing a ghost target. As shown by example  600 , when a radar performs the frequency sweeping (e.g., transmitting chirps) on a target, the target may appear as a peak  602  on a range spectrum. However, if there is another radar (e.g., an interferer) that sweeps the frequency in the same direction, an interference may show up on the range spectrum as a ghost target/false peak  604  on a range spectrum. Thus, the radar device may incorrectly identify the false target as the target. In another example, as shown by diagram  650 , if the radar device and the interferer sweep frequency in an opposite direction (e.g., the interferer uses a different chirp that sweeps down the frequency from high to low), the interference from the interferer may show up as a wideband noise  606  on the range spectrum. Regardless whether the interference shows up as a false target/peak  604  or the wideband noise  606 , the interference may cause the radar device unable to identify the target. 
     Aspects presented herein enable a radar device to address potential interference from another radar signal by performing a timing adjustment action.  FIGS. 7A-7D  illustrate examples of radar operations  700 ,  710 ,  720 , and  730  in accordance with various aspects of the present disclosure. As illustrated in  FIG. 7A , a radar signal  702  may reflect from a target and be received by the transmitting radar device as the radar return  706 .  FIG. 7A  illustrates an example in which the radar return  706  is in proximity with an interference  704 , such as a radar signal from another radar device. For example, the radar return  706  may generate beat frequency f b1  that is too close to interference  704  generating beat frequency f b2 , e.g., within a threshold amount of time. The radar return can be masked by the interference. In order to avoid the problems caused by interference  704 , the radar device may adjust its transmission timing on a per-chirp or a per-frame basis. In some examples, the radar device may randomly adjust the transmission timing of the radar on a per chirp basis. In other examples, the radar device may randomly adjust the transmission timing of the radar on a per frame basis. For example, the radar device may apply a timing adjustment that changes the timing of the transmission signal by a random amount of time, e.g., rather than by a fixed amount of time. In some aspects, a per-chirp timing change may result in faster adaptation than a per-frame timing change. In some aspects, the amount of random timing change may be selected to be large enough to unmask a true radar return signal (e.g., for the radar device to distinguish the radar return of its own radar signal in contrast to the interfering radar signal) according to a threshold probability level.  FIG. 7B  illustrates an example showing a timing adjustment of the radar signal from  FIG. 7A  relative to the interfering radar signal. As shown in  FIG. 7B , after the timing adjustment, at the next chirp or frame, the radar (and/or the interferer) may change its radar transmission timing (e.g., voluntarily without further instructions) with a high probability of changing the frequency difference between the radar signal and the interfering signal, e.g., f b2 , to an amount or location that does not interfere with reception of the radar return. The timing adjustment may be selected to help the beat frequency f b2  to deviate from the beat frequency f b1  with a higher probability, e.g., to increase the likelihood that the radar device will be able to accurately receive the radar return signal to detect targets. The timing adjustments helps the radar device&#39;s operation (e.g., the radar signal  712  and the radar return  716 ) to be less affected by the relocated interference  714  (e.g., that is relocated relative to the radar signal and/or return signal). In the example in  FIG. 7B , the interference may be relocated relative to the radar signal and/or return signal by adjusting the timing of the radar signal, for example. 
     In some aspects, when a radar senses an interfering radar signal from another radar device (e.g., an interfering radar device) that masks a target being tracked, e.g., as described in connection with any of  FIGS. 4, 6A , or  6 B, the radar may inform/request the interfering radar device to change timing to relocate the interference. In some aspects, if a position of the interfering radar device is identifiable (e.g., through sidelink communication, such as V2X positioning, or through global positioning system GPS/Global Navigation Satellite System GNSS), the communication between the radar devices may be done through radar communication. In some aspects, if the interfering radar device is identifiable, the communication between the radar devices may be done through unicasting. For example, the radar device may unicast a request or indication to the interfering radar device to change its radar transmission timing. In some examples, the radar device may send the request or indication may be sent as a sidelink message to the interfering radar device. For example, in  FIG. 4 , the radar device  406  may transmit a request to the radar device  402  to adjust the transmission timing of the radar signal  403 . In other examples, the radar device may transmit the request or indication as a multicast message or a broadcast message. In such aspects, the interfering radar device may respond to the indication or the request by changing the timing of the interference  714  based on the request by the radar. Therefore, the interference  714  is relocated relative to the radar signal based on the coordination of the radar device and the interfering radar device. 
     In some aspects, the radar device may perform a sensing procedure, such as a listen before talk (LBT) procedure, before transmitting a radar signal. LBT is merely one example, and the radar device may perform other sensing procedures in which the radar device monitors for other radar signals that may potentially cause interference to radar measurements of the radar device. For example, the radar may perform LBT before a radar transmission, periodically during radar operation, or when it senses potential interference (e.g., after losing tracked target or sensing elevated interference energy). The radar device may determine a beat frequency f b  between a radar signal that the radar will transmit and a radar signal of an interfering radar device, e.g., in order to identify potential interferers. During the LBT procedure, the radar may identify interferers that are detected as ghost targets, e.g., such as described in connection with any of  FIGS. 4, 6A , or  6 B. The radar may then unicast, broadcast, or multicast a request for the interfering radar device to change timing of a radar signal to relocate interference relative to a signal of the radar device. For example, as illustrated in  FIGS. 7C and 7D  after detecting potential interference  726 , the radar may then unicast, broadcast, or multicast a request to change timing to relocate interference to the inteferer(s). The interfering radar device may adjust the timing of its interfering radar transmission, and the interference  736  may be relocated relative to the radar signal of the radar device. As the radar is performing LBT, there may be no actual radar return that is affected by the interference  726 , e.g., in some examples, the radar device may determine potential interfering radar signals before experiencing the interference to its own radar return signal. The radar device may perform an action, whether adjusting its own radar transmission timing or requesting the interfering radar device to adjust the timing of the potentially interfering radar signal, in order to address the potential interference before transmitting its own radar signal and receiving a radar return signal. 
       FIG. 8  is a flowchart  800  of a method of radar operation. The method may be performed by a first radar device (e.g., the UE  104  comprising a radar module or a radar component  198 ; a radar device  103 ,  406 ; a wireless device  310 ,  350 ; a radar module  362 ; the apparatus  1002 ). Optional aspects are illustrated with a dashed line. The method may enable a radar device to reduce interference caused by an interfering radar signal from another radar device in order to more accurate perform radar detection. 
     At  802 , the first radar device may detect an interfering radar signal from a second radar device that interferes with measurement of a return of a radar signal from the first radar device. The detection  802  may be performed by an interference detection component  1042  in  FIG. 10 . For example,  FIGS. 4, 6A, 6B, 7A, 7B, 7C, and 7D  illustrate example aspects of an interfering radar signal. Based on the interfering radar signal, the first radar device may perform a timing adjustment action in response to detecting the interfering radar signal from the second radar device as described in connection with  808 . In some aspects, the radar signal comprises a FMCW, e.g., such as described in connection with  FIG. 5 . In some aspects detecting the interfering radar signal comprises detecting that the return of the radar signal is masked by the interfering radar signal from the second radar device. 
     In some aspects, at  804 , the first radar device may perform a sensing procedure before transmitting the radar signal, wherein the first radar device detects the interfering radar signal from the second radar device based on the sensing procedure. Example aspects are of sensing procedure are described in connection with  FIGS. 7C and 7D . The sensing  804  may be performed by a sensing component  1044  in  FIG. 10 . In some aspects, the sensing procedure comprises an LBT procedure. In such aspects, detecting the interfering radar signal from the second radar device may include processing, during the sensing procedure, a detected signal from the second radar device to obtain a measurement; determining that the measurement satisfies a threshold; and identifying a result of the sensing procedure based at least in part on the measurement satisfying the threshold. In some aspects, if the measurement is less than the threshold, the result of the sensing procedure comprises a successful result and the first radar device transmits the radar signal without the timing adjustment action. In some aspects, if the measurement is greater than or equal to the threshold, the result of the sensing procedure comprises a failed result that triggers the first radar device to perform the timing adjustment action. 
     At  806 , the first radar device may identify the second radar device, e.g., in order to transmit a unicast message to the second radar device. In some examples, the first radar device may identify the second radar device based on sidelink communication, e.g., such as a sidelink message received from the second radar device. The message may include an identifier or other information that enables the first radar device to identify the second radar device and to transmit communication that is directed to the second radar device, e.g., as a unicast transmission to the second radar device. In some aspects, the second radar device may be identifiable based on the interfering signal. In some aspects, the first radar device may identify a location of the second radar device based on sidelink positioning, such as V2X positioning. The sidelink positioning may include the reception of a sidelink positioning message from the second radar device. In other examples, the first radar device may identify the second radar device based on GPS/GNSS. The identification  806  may be performed by an identify component  1046  in  FIG. 10 . 
     At  808 , the first radar device may perform a timing adjustment action in response to detecting the interfering radar signal from the second radar device. The performance  808  may be performed by a timing adjustment action component  1048  in  FIG. 10 . In some aspects, the timing adjustment action includes adjusting timing of the first radar device&#39;s radar signal, at  808 A. For example, in some aspects, the timing adjustment action comprises adjusting a transmission timing of the radar signal from the first radar device. In some aspects, the first radar device adjusts the transmission timing of the radar signal comprises on a per-chirp basis. In some aspects, the first radar device adjusts the transmission timing of the radar signal by a random amount of time at each chirp. In some aspects, the first radar device adjusts the transmission timing of the radar signal on a per-frame basis. In some aspects, the first radar device adjusts the transmission timing of the radar signal by a random amount of time at each frame. In some aspects, the timing adjustment action includes transmitting a timing adjustment request to the second radar device at  808 B. In some aspects, if the first radar device can identify the second radar device at  806 , the first radar device unicasts the timing adjustment request to the second radar device. In some aspects, if the first radar device can identify a location of the second radar device at  808 B, the first radar device may transmit the timing adjustment request to the second radar device based on radar communication that may be based on the location. In some aspects, the first radar device broadcasts or multicasts the timing adjustment request (e.g., if the first radar device cannot identify the second radar device at  806 ). In some examples, the first radar device may transmit a sidelink transmission with the timing adjustment request. A different term or description may be used than “timing adjustment request,” e.g., the first radar device may provide any indication that indicates for the second radar device to adjust a timing of an interfering radar signal. 
       FIG. 9  is a flowchart  900  of a method of radar operation. The method may be performed by a first radar device (e.g., the UE  104  comprising a radar module or a radar component  198 ; a radar device  103 ,  402 ; a wireless device  310 ,  350 ; a radar module  362 ; the apparatus  1102 ). 
     At  902 , the first radar device may receive a timing adjustment request from a second radar device. The reception  902  may be performed by a timing adjustment request reception component  1142  in  FIG. 11 . In some aspects, the timing adjustment request is received via unicast. In some aspects, the timing adjustment request is received via broadcast. In some aspects, the timing adjustment request is received via multicast. In some examples, the first radar device may receive a sidelink transmission from the second radar device with the timing adjustment request. A different term or description may be used than “timing adjustment request,” e.g., the second radar device may provide any indication that indicates for the first radar device to adjust a timing of an interfering radar signal. 
     At  904 , the first radar device may adjust a transmission timing of a radar signal in response to the timing adjustment request from the second radar device. The adjustment may be performed by a timing adjustment component  1144  in  FIG. 11 . In some aspects, the first radar device adjusts the transmission timing of the radar signal comprises on a per-chirp basis. In some aspects, the first radar device adjusts the transmission timing of the radar signal by a random amount of time at each chirp. In some aspects, the first radar device adjusts the transmission timing of the radar signal on a per-frame basis. In some aspects, the first radar device adjusts the transmission timing of the radar signal by a random amount of time at each frame. 
       FIG. 10  is a diagram  1000  illustrating an example of a hardware implementation for an apparatus  1002 . The apparatus  1002  is a radar device and includes a control unit  1004 . The control unit  1004  may communicate through a transceiver  1022 , which may include a cellular RF transceiver, with a UE  104  that is in communication with or includes a radar module, a base station  102 / 180 , another radar device  103 , etc. The transceiver may also transmit a radar signal and receive a reflection of the radar signal, e.g., in order to detect a target  107 , to monitor the environment of the apparatus  1002 , etc. In some examples, the cellular RF transceiver and the radar transceiver may comprise separate components. The control unit  1004  may include a computer-readable medium/memory. The control unit  1004  is responsible for general processing, including the execution of software stored on the computer-readable medium/memory. The software, when executed by the control unit  1004 , causes the control unit  1004  to perform the various functions described supra. The computer-readable medium/memory may also be used for storing data that is manipulated by the control unit  1004  when executing software. The control unit  1004  further includes a reception component  1030 , a radar manager  1032 , and a transmission component  1034 . The radar manager  1032  includes the one or more illustrated components. The components within the radar manager  1032  may be stored in the computer-readable medium/memory and/or configured as hardware within the control unit  1004 . The control unit  1004  may be a component of the wireless device  310  and may include the memory  376  and/or at least one of the TX processor  316 , the RX processor  370 , and the controller/processor  375 . The apparatus may further include a radar sensor module  1024 . The radar sensor module  1024  may include additional components, such as a radar sensor component configured to transmit radar signals, a GPS component, or the like. 
     The radar manager  1032  includes an interference detection component  1042  that detects an interfering radar signal from a second radar device that interferes with measurement of a return of a radar signal from the first radar device, e.g., as described in connection with  802  in  FIG. 8 . The radar manager  1032  further includes a sensing component  1044  that performs a sensing procedure before transmitting the radar signal, wherein the first radar device detects the interfering radar signal from the second radar device based on the sensing procedure, e.g., as described in connection with  804  in  FIG. 8 . The radar manager  1032  further includes an identify component  1046  that identifies the second radar device, e.g., as described in connection with  806  in  FIG. 8 . The radar manager  1032  further includes a timing adjustment action component  1048  that performs a timing adjustment action in response to detecting the interfering radar signal from the second radar device, e.g., as described in connection with  808  in  FIG. 8 . 
     The apparatus may include additional components that perform each of the blocks of the algorithm in the aforementioned flowchart of  FIG. 8 . As such, each block in the aforementioned flowchart of  FIG. 8  may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof. 
     In one configuration, the apparatus  1002 , and in particular the control unit  1004 , includes means for detecting an interfering radar signal from a second radar device that interferes with measurement of a return of a radar signal from the first radar device. The control unit  1004  may further include means for performing a timing adjustment action in response to detecting the interfering radar signal from the second radar device. The control unit  1004  may further include means for adjusting a transmission timing of the radar signal from the first radar device. The control unit  1004  may further include means for transmitting a timing adjustment request to the second radar device. The control unit  1004  may further include means for identifying the second radar device. The control unit  1004  may further include means for performing a sensing procedure before transmitting the radar signal, wherein the first radar device detects the interfering radar signal from the second radar device based on the sensing procedure. The control unit  1004  may further include means for processing, during the sensing procedure, a detected signal from the second radar device to obtain a measurement. The control unit  1004  may further include means for determining that the measurement satisfies a threshold. The control unit  1004  may further include means for identifying a result of the sensing procedure based at least in part on the measurement satisfying the threshold. The aforementioned means may be one or more of the aforementioned components of the apparatus  1002  configured to perform the functions recited by the aforementioned means. As described supra, the apparatus  1102  may include the TX Processor  368 , the RX Processor  356 , and the controller/processor  359 . As such, in one configuration, the aforementioned means may be the TX Processor  368 , the RX Processor  356 , the radar module  362 , and the controller/processor  375  configured to perform the functions recited by the aforementioned means. 
       FIG. 11  is a diagram  1100  illustrating an example of a hardware implementation for an apparatus  1102 . The apparatus  1102  is a radar device and includes a control unit  1104 . The control unit  1104  may communicate through a transceiver  1122 , which may include a cellular RF transceiver, that is in communication with a UE  104  that includes a radar module, a base station  102 / 180 , another radar device  103 , etc. The transceiver may also transmit a radar signal and receive a reflection of the radar signal, e.g., in order to detect a target  107 , to monitor the environment of the apparatus  1002 , etc. In some examples, the cellular RF transceiver and the radar transceiver may comprise separate components. The control unit  1104  may include a computer-readable medium/memory. The control unit  1104  is responsible for general processing, including the execution of software stored on the computer-readable medium/memory. The software, when executed by the control unit  1104 , causes the control unit  1104  to perform the various functions described supra. The computer-readable medium/memory may also be used for storing data that is manipulated by the control unit  1104  when executing software. The control unit  1104  further includes a reception component  1130 , a radar manager  1132 , and a transmission component  1134 . The radar manager  1132  includes the one or more illustrated components. The components within the radar manager  1132  may be stored in the computer-readable medium/memory and/or configured as hardware within the control unit  1104 . The control unit  1104  may be a component of the BS  310  and may include the memory  376  and/or at least one of the TX processor  316 , the RX processor  370 , and the controller/processor  375 . The apparatus may further include a radar sensor module  1124 . The radar sensor module  1124  may include additional components, such as a radar sensor component configured to transmit radar signals, a GPS component, or the like. 
     The radar manager  1132  includes a timing adjustment request reception component  1142  that receives a timing adjustment request from a second radar device, e.g., as described in connection with  902  in  FIG. 9 . The radar manager  1132  further includes a timing adjustment component  1144  that adjusts a transmission timing of a radar signal in response to the timing adjustment request from the second radar device, e.g., as described in connection with  904  in  FIG. 9 . 
     The apparatus may include additional components that perform each of the blocks of the algorithm in the aforementioned flowchart of  FIG. 9 . As such, each block in the aforementioned flowchart of  FIG. 9  may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof. 
     In some examples, an apparatus may be capable of performing the aspects of both  FIG. 8  and  FIG. 9 . Thus, the apparatus may include a combination of components  1042 ,  1044 ,  1046 ,  1048 ,  1142 , and  1144 . 
     In one configuration, the apparatus  1102 , and in particular the control unit  1104 , includes means for receiving a timing adjustment request from a second radar device and means for adjusting a transmission timing of a radar signal in response to the timing adjustment request from the second radar device. The aforementioned means may be one or more of the aforementioned components of the apparatus  1102  configured to perform the functions recited by the aforementioned means. As described supra, the apparatus  1102  may include the TX Processor  368 , the RX Processor  356 , and the controller/processor  359 . As such, in one configuration, the aforementioned means may be the TX Processor  368 , the RX Processor  356 , the radar module  362 , and the controller/processor  375  configured to perform the functions recited by the aforementioned means. 
     It is understood that the specific order or hierarchy of blocks in the processes/flowcharts disclosed is an illustration of example approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes/flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented. 
     The previous description is provided to enable any 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 intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Terms such as “if,” “when,” and “while” should be interpreted to mean “under the condition that” rather than 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. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. All structural and functional equivalents to the 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 intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in 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.” 
     The following aspects are illustrative only and may be combined with other aspects or teachings described herein, without limitation. 
     Aspect 1 is a method at a first radar device, comprising: detecting an interfering radar signal from a second radar device that interferes with measurement of a return of a radar signal from the first radar device; and performing a timing adjustment action in response to detecting the interfering radar signal from the second radar device. 
     Aspect 2 is the method of aspect 1, wherein the timing adjustment action comprises adjusting a transmission timing of the radar signal from the first radar device. 
     Aspect 3 is the method of aspect 2, wherein the first radar device adjusts the transmission timing of the radar signal comprises on a per-chirp basis. 
     Aspect 4 is the method of aspect 3, wherein the first radar device adjusts the transmission timing of the radar signal by a random amount of time at each chirp. 
     Aspect 5 is the method of aspect 2, wherein the first radar device adjusts the transmission timing of the radar signal on a per-frame basis. 
     Aspect 6 is the method of aspect 3, wherein the first radar device adjusts the transmission timing of the radar signal by a random amount of time at each frame. 
     Aspect 7 is the method of aspect 1 or 2, wherein the timing adjustment action comprises transmitting a timing adjustment request to the second radar device. 
     Aspect 8 is the method of aspect 7, wherein the first radar device unicasts the timing adjustment request to the second radar device. 
     Aspect 9 is the method of aspect 8, further comprising: transmitting the timing adjustment action via a radar communication based on a location of the second radar device through sidelink positioning or a GPS. 
     Aspect 10 is the method of aspect 7, wherein the first radar device broadcasts the timing adjustment request. 
     Aspect 11 is the method of aspect 7, wherein the first radar device multicasts the timing adjustment request. 
     Aspect 12 is the method of any of aspects 1 to 11, further comprising: performing a sensing procedure before transmitting the radar signal, wherein the first radar device detects the interfering radar signal from the second radar device based on the sensing procedure. 
     Aspect 13 is the method of aspect 12, wherein the sensing procedure comprises an LBT procedure. 
     Aspect 14 is the method of aspect 12 or 13, wherein detecting the interfering radar signal from the second radar device comprises: processing, during the sensing procedure, a detected signal from the second radar device to obtain a measurement; determining that the measurement satisfies a threshold; and identifying a result of the sensing procedure based at least in part on the measurement satisfying the threshold. 
     Aspect 15 is the method of aspect 14, wherein if the measurement is less than the threshold, the result of the sensing procedure comprises a successful result and the first radar device transmits the radar signal without the timing adjustment action. 
     Aspect 16 is the method of aspect 14 or 15, wherein if the measurement is greater than or equal to the threshold, the result of the sensing procedure comprises a failed result that triggers the first radar device to perform the timing adjustment action. 
     Aspect 17 is the method of any of aspects 14-16, wherein the radar signal comprises a FMCW. 
     Aspect 18 is the method of any of aspects 14-17, wherein detecting the interfering radar signal comprises detecting that the return of the radar signal is masked by the interfering radar signal from the second radar device. 
     Aspect 19 is a method at a first radar device, comprising: receiving a timing adjustment request from a second radar device; and adjusting a transmission timing of a radar signal in response to the timing adjustment request from the second radar device. 
     Aspect 20 is the method of aspect 19, wherein the first radar device adjusts the transmission timing of the radar signal comprises on a per-chirp basis. 
     Aspect 21 is the method of aspect 20, wherein the first radar device adjusts the transmission timing of the radar signal by a random amount of time at each chirp. 
     Aspect 22 is the method of aspect 19, wherein the first radar device adjusts the transmission timing of the radar signal on a per-frame basis. 
     Aspect 23 is the method of aspect 22, wherein the first radar device adjusts the transmission timing of the radar signal by a random amount of time at each frame. 
     Aspect 24 is the method of any of aspects 19-23, wherein the timing adjustment request is received via unicast. 
     Aspect 25 is the method of any of aspects 19-23, wherein the timing adjustment request is received via broadcast. 
     Aspect 26 is the method of any of aspects 19-23, wherein the timing adjustment request is received via multicast. 
     Aspect 27 is a radar device including at least one processor coupled to a memory and configured to implement a method as in any of aspects 1 to 18. 
     Aspect 28 is a radar device including at least one processor coupled to a memory and configured to implement a method as in any of aspects 19 to 26. 
     Aspect 29 is a radar device including means for implementing a method as in any of aspects 1 to 18. 
     Aspect 30 is a radar device including means for implementing a method as in any of aspects 19 to 26. 
     Aspect 31 is a non-transitory computer-readable storage medium storing computer executable code, where the code when executed by a processor causes the processor to implement a method as in any of aspects 1 to 18. 
     Aspect 31 is a non-transitory computer-readable storage medium storing computer executable code, where the code when executed by a processor causes the processor to implement a method as in any of aspects 19 to 26.