Enhanced Doppler division multiplexing (DDM) multiple-input multiple-output (MIMO) sensing based on Doppler spectrum puncturing

Abstract

Systems and techniques for wireless communication are disclosed. For example, a network device may transmit a sensing signal for sensing one or more targets. The transmitted sensing signal and at least one sensing signal transmitted by at least one other network device of the plurality of network devices include one or more phase codes and a same frequency modulated carrier (FMCW). Each phase code of each sensing signal corresponds to one or more Doppler spectrum patterns. A network device may receive at least one echo signal from one or more targets. The network device may mitigate Doppler ambiguity in the Doppler spectrum from the at least one echo signal based on the one or more Doppler spectrum patterns.

Description

TECHNICAL FIELD

[0001] The present disclosure generally relates to scheduling and / or processing of sensing and communication signals for joint communication and sensing. For example, aspects of the present disclosure relate to providing enhancements to Doppler Division Multiplexing (DDM) Multiple Input Multiple Output (MIMO) sensing based on Doppler spectrum puncturing. BACKGROUND

[0002] Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, and broadcast. These systems can be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple- access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems, which can be referred to as New Radio (NR) systems. These systems can employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple-access communications system can include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which can be otherwise known as user equipment (UE). Some wireless communications systems can support communication between UEs, which can involve direct transmission between two or more UEs.

[0003] As larger bandwidths are allocated for wireless cellular communications systems (e.g., including 5G and beyond) and more use cases are introduced into cellular communications systems, Doppler Division Multiplexing (DDM) Multiple Input Multiple Output (MIMO) sensing can be a fundamental feature of existing or future wireless communications systems, such as to enhance the overall spectral efficiency of wireless communications networks. SUMMARY

[0004] The following presents a simplified summary related to one or more aspects disclosed herein. Thus, the following summary should not be considered an extensive overview relating to all contemplated aspects, nor should the following summary be considered to identify key or critical elements relating to all contemplated aspects or to delineate the scope associated with any particular aspect. Accordingly, the following summary is merely presented to provide a simplified summary of certain concepts related to one or more aspects disclosed herein, and the detailed description presented below will describe and explain various aspects related to the mechanisms disclosed herein.

[0005] Systems and techniques for wireless communication are described. According to at least one example, a network device of a plurality of network devices for wireless communication is provided. The network device includes at least one memory and at least one processor coupled to the at least one memory and configured to: output, for transmission, a sensing signal for sensing one or more targets, wherein the sensing signal and at least one sensing signal transmitted by at least one other network device of the plurality of network devices include one or more phase codes and a same frequency modulated carrier wave (FMCW), and wherein each phase code of each sensing signal corresponds to one or more Doppler spectrum patterns; receive, from the one or more targets, at least one echo signal; and mitigate, based on the one or more Doppler spectrum patterns, Doppler ambiguities in a Doppler spectrum from the at least one echo signal.

[0006] In another illustrative example, a method for wireless communication at a network device is provided. The method includes transmitting, by the network device, a sensing signal for sensing one or more targets, wherein the transmitted sensing signal and at least one sensing signal transmitted by at least one other network device of the plurality of network devices include one or more phase codes and a same frequency modulated carrier wave (FMCW), and wherein each phase code of each sensing signal corresponds to one or more Doppler spectrum patterns; receiving, by the network device, from the one or more targets, at least one echo signal; and mitigating, by the network device, based on the one or more Doppler spectrum patterns, Doppler ambiguities in a Doppler spectrum from the at least one echo signal.

[0007] In another illustrative example, a non-transitory computer-readable medium of a network device of a plurality of network devices is provided. The non-transitory computer-readable medium has instructions stored thereon that, when executed by at least one processor, cause the at least one processor to: output, for transmission, a sensing signal for sensing one or more targets, wherein the sensing signal and at least one sensing signal transmitted by at least one other network device of the plurality of network devices include one or more phase codes and a same frequency modulated carrier wave (FMCW), and wherein each phase code of each sensing signal corresponds to one or more Doppler spectrum patterns; receive, from the one or more targets, at least one echo signal; and mitigate, based on the one or more Doppler spectrum patterns, Doppler ambiguities in a Doppler spectrum from the at least one echo signal.

[0008] In another illustrative example, a network device of a plurality of network devices for wireless communication is provided. The apparatus includes means for transmitting a sensing signal for sensing one or more targets, wherein the transmitted sensing signal and at least one sensing signal transmitted by at least one other network device of the plurality of network devices include one or more phase codes and a same frequency modulated carrier wave (FMCW), and wherein each phase code of each sensing signal corresponds to one or more Doppler spectrum patterns; means for receiving at least one echo signal from the one or more targets; and means for mitigating Doppler ambiguities in a Doppler spectrum from the at least one echo signal based on the one or more Doppler spectrum patterns.

[0009] In some aspects, the network device, apparatus, or one or more of the other devices described herein is, is a part of, and / or includes a user equipment (UE), a base station (e.g., a gNodeB (gNB) or eNodeB (eNB)) or a part of a base station (e.g., one or more of a central unit (CU), a distributed unit (DU), a radio unit (RU), a near real-time (near-RT) RAN intelligent controller (RIC), or a non-real-time (non-RT) RIC of a base station). The UE can be a wearable device, an extended reality (XR) device (e.g., a virtual reality (VR) device, an augmented reality (AR) device, or a mixed reality (MR) device), a head-mounted display (HMD) device, a wireless communication device, a mobile device (e.g., a mobile phone and / or mobile handset and / or a so-called “smart phone” or other mobile device), a camera, a personal computer, a laptop computer, a server computer, a vehicle, or a computing device or component of a vehicle, another device, or a combination thereof. In some aspects, the one or more of the network device, apparatus, or other devices can include one or more cameras for capturing one or more images. In some examples, the one or more of the network device, apparatus, or other devices can also include a display for displaying one or more images, notifications, and / or other displayable data. In some cases, the one or more of the network device, apparatus, or other devices can include one or more receivers, transmitters, or transceivers for receiving and / or transmitting wireless communications.

[0010] This Summary is intended to identify key or essential features of the claimed subject matter, but this Summary alone is not intended to be used in determining the scope of the claimed subject matter. The subject matter should be understood from the entire description of the patent, with appropriate portions of the description, any or all drawings and the claims being consulted.

[0011] The foregoing and other features and aspects will become more apparent from the following description and accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0012] The accompanying drawings are presented to aid in the description of various aspects of the disclosure and are provided solely for illustration of the various aspects and are not intended as a definition of the aspects.

[0013] Figure 1 is a diagram illustrating an example wireless communication system that can be employed by the disclosed enhanced systems and techniques for Doppler spectrum-punching based Doppler division multiplexing (DDM) multiple-input multiple-output (MIMO) sensing, in accordance with some aspects of the present disclosure.

[0014] Figure 2 is a diagram illustrating an example of a disaggregated base station architecture that can be employed by the disclosed enhanced systems and techniques for Doppler spectrum-punching based DDM MIMO sensing, in accordance with some aspects of the present disclosure.

[0015] Figure 3 is a diagram illustrating an example of a frame structure that can be employed by the disclosed enhanced systems and techniques for Doppler spectrum-punching based DDM MIMO sensing, in accordance with some aspects of the present disclosure.

[0016] Figure 4 is a block diagram illustrating an example of a computing system of an electronic device that can be employed by the disclosed enhanced systems and techniques for Doppler spectrum-punching based DDM MIMO sensing, in accordance with some aspects of the present disclosure.

[0017] Figure 5 is a diagram illustrating an example of a wireless device utilizing radio frequency (RF) single station sensing techniques that can be employed by the disclosed systems and techniques described herein for determining one or more characteristics of a target object, in accordance with some aspects of the present disclosure.

[0018] Figure 6 is a diagram illustrating an example of a receiver utilizing RF two-station sensing techniques with one transmitter that can be employed by the disclosed systems and techniques described herein for determining one or more characteristics of a target object, in accordance with some aspects of the present disclosure.

[0019] Figure 7 is a diagram illustrating an example of a receiver utilizing RF two-station sensing techniques with multiple transmitters that can be employed by the disclosed systems and techniques described herein for determining one or more characteristics of a target object, in accordance with some aspects of the present disclosure.

[0020] Figure 8 is a diagram illustrating an example geometry for two-station (or single station) sensing, in accordance with some aspects of the present disclosure.

[0021] Figure 9 is a diagram illustrating two-station distance for two-station sensing, in accordance with some aspects of the present disclosure.

[0022] Figure 10 FIG. 1 is a diagram illustrating an example of devices involved in wireless communication (e.g., sidelink communication) in accordance with some aspects of the present disclosure.

[0023] Figure 11 FIG. 3 is a diagram illustrating an example of an existing comb structure for reference signals.

[0024] Figure 12 FIG. 4 is a diagram illustrating an example of a system for enhanced DDM MIMO sensing based on Doppler spectrum puncturing in accordance with some aspects of the present disclosure, where the system is performing bistatic sensing of a target.

[0025] Figure 13 FIG. 5 is a diagram illustrating an example of chirps transmitted by multiple antennas in accordance with some aspects of the present disclosure.

[0026] Figure 14A FIG. 6 is a diagram illustrating an example of Doppler frequencies from transmissions by two antennas in accordance with some aspects of the present disclosure.

[0027] Figure 14B FIG. 7 is a spectrogram illustrating an example of range-velocity profiles for a DDM MIMO radar with two transmit antennas in accordance with some aspects of the present disclosure.

[0028] Figure 15A FIG. 8 is a diagram illustrating an example of chirps transmitted by four antennas in accordance with some aspects of the present disclosure.

[0029] Figure 15B FIG. 9 is a diagram illustrating an example of Doppler frequencies from transmissions by four antennas in accordance with some aspects of the present disclosure, where the null subbands are contiguous.

[0030] Figure 15C FIG. 10 is a table illustrating an example of Doppler spectrum patterns in accordance with some aspects of the present disclosure, where the null subbands are contiguous.

[0031] Figure 16A FIG. 11 is a diagram illustrating an example of chirps transmitted by four antennas in accordance with some aspects of the present disclosure.

[0032] Figure 16B FIG. 12 is a diagram illustrating an example of Doppler frequencies from transmissions by four antennas in accordance with some aspects of the present disclosure, where the null subbands are non-contiguous.

[0033] Figure 16C FIG. 13 is a table illustrating an example of Doppler spectrum patterns in accordance with some aspects of the present disclosure, where the null subbands are non-contiguous.

[0034] Figure 17is a diagram illustrating an example of Doppler frequencies for transmission of MIMO sensing with four different users, in accordance with some aspects of the present disclosure.

[0035] Figure 18 is a diagram illustrating an example of Doppler frequencies for transmission from four antennas, where periodicity of one sub-band is doubled, in accordance with some aspects of the present disclosure.

[0036] Figure 19 is a flow diagram illustrating an example of a process for wireless communications utilizing enhanced methods for Doppler spectrum based punctured DDM MIMO sensing, in accordance with some aspects of the present disclosure.

[0037] Figure 20 is a block diagram illustrating an example of a computing system that can be employed by the disclosed enhanced system for Doppler spectrum based punctured DDM MIMO sensing, in accordance with some aspects of the present disclosure. DETAILED DESCRIPTION

[0038] For illustrative purposes, certain aspects of the present disclosure are provided below. Alternate aspects can be devised without departing from the scope of the present disclosure. Additionally, well-known elements of the present disclosure, related to those described below, can not be described or will be omitted so as to not obscure the relevant details of the present disclosure. Some aspects described herein can be independently applied, and others can be applied in combination. This will be apparent from the following description.

[0039] The following description provides examples of aspects only and is not intended to limit the scope, applicability, or configuration of the present disclosure. Rather, the following description of the example aspects will provide those skilled in the art with an enabling description for implementing an example aspect. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the present disclosure as set forth in the appended claims.

[0040] A radar sensing system uses radio frequency (RF) waveforms to perform RF sensing to determine or estimate one or more characteristics of a target object, such as a distance, an angle, and / or a velocity of the target object. The target object can include a vehicle, an obstacle, a user, a building, or other objects. A typical radar system includes at least one transmitter, at least one receiver, and at least one processor. When employing one receiver that is co-located with the transmitter, the radar sensing system can perform monostatic sensing. When employing one receiver of a first device that is located away from the transmitter of a second device, the radar system can perform bistatic sensing. Similarly, when employing multiple receivers of multiple devices that are all located away from at least one transmitter of at least one device, the radar system can perform multistatic sensing.

[0041] During operation of the radar sensing system, the transmitter transmits an electromagnetic (EM) signal in the RF domain toward a target object. The signal reflects off the target object to produce one or more reflected signals that provide information or properties about the target, such as a location and a velocity of the target object. The at least one receiver receives the one or more reflected signals, and the at least one processor associated with the at least one receiver utilizes information from the one or more reflected signals to determine the information or properties of the target object. The target object can also be referred to herein as a target.

[0042] Generally, RF sensing involves monitoring a moving target with different motions (e.g., a moving car or a pedestrian, a body motion of a person such as breathing, and / or other micro-motions related to the target). The Doppler, which measures the phase change in the signal and indicates the motion, is an important characteristic for sensing the target.

[0043] In some cases, a radar sensing signal, which can be referred to as a radar reference signal (RS) such as a sensing reference signal (S-RS), can be designed for and used for sensing purposes. A radar RS is typically designed for sensing purposes only (e.g., not for communication purposes). In contrast, a communication RS such as a demodulation reference signal (DMRS) is typically designed for and used for communication purposes only, such as estimating channel parameters for communication.

[0044] A cellular communication system is designed to transmit communication signals on a designated communication frequency band (e.g., 23 gigahertz (GHz) for 5G / NR, 3.5 GHz, etc., 2.2 GHz for LTE, and so on). An RF sensing system is designed to transmit RF sensing signals on a designated radar RF band (e.g., 77 GHz for autonomous driving). Future cellular communication systems can use a common spectrum for communication and sensing, in which case communication and sensing should be considered jointly.

[0045] MIMO is a multiple antenna spectral efficient technology and has been a major driving force for the next generation of antenna technology for cellular networks. MIMO systems can send more than one signal on the same channel, providing increased spectral efficiency and total throughput. By exploiting spatial separation, the antennas of a MIMO system are spaced apart at specific distances and angles for various purposes, such as to reduce correlation between different sub-channels, to achieve precoding / beamforming purposes, etc. MIMO systems can provide a robust wireless communication mechanism to address fading and shadowing caused by multiple transmission paths and long distances. In a MIMO system, various data streams can be transmitted simultaneously, which can provide multiplexing gain and improvement to total throughput. For at least these reasons, MIMO has recently been used in cellular wireless communication technology and is included in various next generation wireless projects and standards, including 5G NR.

[0046] One simple form of MIMO is point-to-point MIMO. In point-to-point MIMO, two systems (e.g., a base station and a UE) each employ multiple antennas to communicate with each other. The use of multiple antennas provides increased capacity of the air interface. However, point-to-point MIMO employs a multiple antenna configuration that requires additional hardware at both the base station and the end user equipment (e.g., in the UE). The need for additional hardware at both the base station and the user equipment disadvantages point-to-point MIMO because it increases overall system complexity. In some cases, the end user equipment (e.g., a UE) of a mobile communication system can not be able to support multiple antennas, such as due to its small physical size and / or low cost requirements of the UE device.

[0047] A feature of point-to-point MIMO is single user MIMO (SU-MIMO), which provides increased data rates by sending multiple data streams to a particular user equipment (e.g., a particular UE). Similar to point-to-point MIMO, SU-MIMO has the disadvantage of requiring user equipment (e.g., a UE) to support multiple antennas.

[0048] In contrast to point-to-point MIMO and SU-MIMO, multi-user MIMO (MU-MIMO) does not have the disadvantage of requiring user equipment to support multiple antennas. In MU-MIMO, multiple users share the same time and frequency resources, while each base station (e.g., a next generation NodeB (gNB), an evolved NodeB (eNB), or a part thereof such as a central unit (CU), a distributed unit (DU), a radio unit (RU), a near real-time (near-RT) RAN intelligent controller (RIC), or a non-RT RIC) is equipped with multiple antennas (e.g., an antenna array) and simultaneously serves many users (e.g., UEs). Each end user equipment (e.g., UE) can employ a single antenna or multiple antennas. In the case where the end user equipment uses a single antenna, complex hardware can only be required at the base station side. For MU-MIMO systems, the cost and complexity of the antenna system is significantly reduced, as low-cost single antennas (e.g., dipole antennas) can be used for end user equipment (e.g., UEs), and more expensive, complex hardware can only be used at the base station side.

[0049] Due to the diversity of the distance, angle, and quality of the signals of the multiple users in the MU-MIMO system, the performance of the MU-MIMO system is generally less affected by the transmission environment compared to point-to-point MIMO. This advantage is achieved by the MU-MIMO system employing selective beamforming and power control to eliminate interference. MU-MIMO systems provide high reliability and throughput, and thus, have become an integral part of wireless communication systems including Wi-Fi, LTE, and 5G networks.

[0050] Massive MIMO (mMIMO) is a form of MU-MIMO that employs a larger number of antennas at the base station than MU-MIMO, and thus, the number of served users (e.g., UEs) can be significantly increased compared to MU-MIMO systems (e.g., in mMIMO, a single base station with many antennas can serve a large number of users). With a large number of antennas in each base station, the channel vector between a user (e.g., UE) and a base station is almost rectangular for each pair, and thus, can provide exceptionally linear transmission. In mMIMO, large throughput can be achieved due to multiplexing gain, diversity gain, and array gain. In mMIMO, the large number of antennas at the base station can serve hundreds of users with the same frequency resources by exploiting antenna beamforming techniques.

[0051] In mMIMO, the more antennas each base station employs, the more robust the communication operation. In theory, mMIMO can employ an unlimited number of antennas at each of the base stations. However, typically (e.g., in 5G networks), 64 to 128 antennas (e.g., 64 receive antennas and 64 transmit antennas) are already in practical use in mMIMO base stations. One advantage of mMIMO is that sophisticated hardware can be required only at the base stations, not at the user equipment (e.g., UEs), which can each use a single antenna and simple antenna design. Another advantage of mMIMO is that it has a scalable architecture that can easily be scaled up in proportion to serve more users, only requiring upgrading the antenna system on the base stations.

[0052] Currently, some radars (e.g., automotive radars) transmit signals with a frequency-modulated continuous wave (FMCW) waveform. The FMCW waveform (also referred to as a chirp or a pulse) is a complex sinusoid whose frequency increases linearly with time. The FMCW radar transmits chirps (e.g., chirps 1310a, 1310b, 1310c of FIG. 13) in a periodic manner, where the period is referred to as the pulse repetition interval (PRI). Target echoes at the radar receiver can contain delayed and attenuated copies of the transmitted chirp. The received signal mixes with the transmitted chirp, which produces a complex sinusoid referred to as the beat signal. Figure 13

[0053] The process of obtaining the beat signal can be implemented in the RF domain by using a mixer followed by a bandpass filter (BPF) to remove signals with frequencies outside the band of interest, which also imposes a limit on the maximum detectable range. After sampling the beat signal, estimation of the beat frequency can be implemented in the digital domain. In many scenarios (e.g., automotive scenarios), the beat frequency is much smaller than the signal bandwidth, and thus, a low-cost, low-speed analog-to-digital converter (ADC) can be used to sample the beat signal. FMCW waveforms are commonly used within the radar industry due to their high performance-to-cost ratio, which is provided at least in part by the implementation of low-cost ADCs. The time during one period or chirp is often referred to as “fast time,” while the time across multiple periods or chirps is often referred to as “slow time.” For example, if the beat signal is sampled and the samples for each chirp are placed within the columns of a matrix, the row index of the matrix corresponds to fast time and the column index corresponds to slow time. By applying a fast Fourier transform (FFT) to the sampled beat signal along fast time, the range frequency can be determined. A second FFT can be applied along slow time to determine the Doppler frequency. The application of these two FFTs is equivalent to a two-dimensional (2D) FFT of the beat signal in fast time and slow time. The result of this 2D FFT operation produces a 2D range-Doppler spectrum (e.g., spectrogram 1402 of FIG. 14). Figure 14B ​​

[0054] The 2D FFT operation for beat frequency estimation can be computed with a low-cost digital signal processor (DSP) or field programmable gate array (FPGA). The range resolution depends on the beat frequency resolution. The low hardware cost (e.g., low-cost ADC) combined with the high range resolution that can be achieved makes the use of FMCW radars very attractive for a variety of different radar applications, including automotive radar applications.

[0055] In some scenarios, a MIMO radar can be employed to transmit FMCW sequences. For these cases, the transmit antennas of the MIMO radar can transmit the FMCW sequences in a way that guarantees the orthogonality of the FMCW sequences. At each receive antenna (e.g., of the MIMO radar), the contribution of each transmit antenna can be extracted by exploiting the waveform orthogonality. The waveform orthogonality can be achieved while transmitting FMCW using a variety of different techniques, including but not limited to Doppler division multiplexing (DDM).

[0056] To achieve waveform orthogonality while transmitting FMCW using DDM, the pulse repetition interval should be chosen such that the number of transmitted pulses is equal to the number of transmit antennas . The total number of chirps (i.e., pulses) N is transmitted sequentially. All transmit antennas should transmit the same FMCW waveform simultaneously after multiplying the FMCW waveform with a phase code that is different for each antenna and changes between pulses, where the transmitted waveform is with m = 1, 2,..., and n = 0, 1, 2,..., N - 1. To separate the h-th transmit signal at the l-th receiver, a slow-time Doppler demodulation can be applied to all range bins corresponding to the same chirp after performing a range FFT. The Doppler demodulation output of the N number of chirps can be assembled into a vector . A Doppler FFT can then be applied to the vector

[0057] . In one or more examples, to separate the transmit signals in the Doppler domain, a phase code can be employed to shift the Doppler FFT of the interference to a frequency higher than the maximum detectable Doppler frequency . A low-pass filter (LPF) can then be applied to remove the interference. An example of a phase code is with m = 1, 2,..., and n = 0, 1, 2,..., N - 1, and where the starting phase is linear across different transmit antennas such that . With this approach, the radar pulse repetition frequency should be greater than If the maximum unambiguous Doppler frequency is kept constant, then the maximum detectable unambiguous Doppler frequency decreases to Doppler unwrapping or de-aliasing algorithms with different Doppler spreads at different observation periods can be very beneficial to mitigate Doppler aliasing.

[0058] In some aspects of the disclosure, systems, apparatuses, methods (also referred to as procedures), and computer-readable media (collectively referred to herein as “systems and techniques”) are described herein that provide solutions for enhancing DDM MIMO sensing based on Doppler spectrum puncturing. The systems and techniques provide solutions to remove or mitigate Doppler aliasing that can be caused by aliasing issues.

[0059] The systems and techniques described herein provide various advantages over existing systems, including but not limited to improving RF sensing performance, reducing hardware cost, and improving communication efficiency, among other benefits.

[0060] Additional aspects of the disclosure are described in more detail below.

[0061] As used herein, the terms “user equipment” (UE) and “network entity” are not intended to be specific to or otherwise limited to any particular radio access technology (RAT), unless otherwise indicated. Generally, a UE can be any wireless communication device (e.g., a mobile phone, a router, a tablet computer, a laptop computer, and / or a tracking device, etc.), a wearable device (e.g., a smart watch, smart glasses, a wearable ring, and / or an extended reality (XR) device such as a virtual reality (VR) headset, an augmented reality (AR) headset or glasses, or a mixed reality (MR) headset), a vehicle (e.g., a car, a motorcycle, a bicycle, etc.), and / or an Internet of Things (IoT) device, etc., for a user to communicate on a wireless communication network. A UE can be mobile or can (for example, at certain times) be stationary, and can communicate with a Radio Access Network (RAN). As used herein, the term “UE” can be referred to interchangeably as an “access terminal” or “AT,” a “client device,” a “wireless device,” a “subscriber device,” a “subscriber terminal,” a “subscriber station,” a “user terminal” or “UT,” a “mobile device,” a “mobile terminal,” a “mobile station,” or variations thereof. Generally, UEs can communicate with a core network via a RAN, and through the core network the UEs can be connected with external networks like the Internet and with other UEs. Of course, other mechanisms of connecting to the core network and / or the Internet are also possible for the UEs, such as over wired access networks, wireless local area network (WLAN) networks (e.g., based on IEEE 802.11 communication standards, etc.), and so on.

[0062] A network entity can be implemented in an aggregated or monolithic base station architecture, or alternatively, in a disaggregated base station architecture, and can include one or more of a central unit (CU), a distributed unit (DU), a radio unit (RU), a near- real-time (near-RT) RAN intelligent controller (RIC), or a non-RT RIC. A base station (e.g., with an aggregated / monolithic base station architecture or a disaggregated base station architecture) can operate according to one of a number of RATs in communication with UEs (depending on the network in which it is deployed), and can alternatively be referred to as an access point (AP), a network node, a NodeB, an evolved NodeB (eNB), a next generation eNB (ng-eNB), a New Radio (NR) Node B (also referred to as a gNB or gNodeB), etc. A base station can be used primarily to support wireless access by UEs using the supported RATs, including supporting data, voice, and / or signaling connections for the UEs. In some systems, a base station can provide edge node signaling functions, while in other systems, a base station can provide additional control and / or network management functions. A communication link through which UEs can send signals to a base station is called an uplink (UL) channel (e.g., a reverse traffic channel, a reverse control channel, an access channel, etc.). A communication link through which the base station can send signals to a UE is called a downlink (DL) or forward link channel (e.g., a paging channel, a control channel, a broadcast channel, or a forward traffic channel, etc.). As used herein, the term traffic channel (TCH) can refer to an uplink, reverse, or downlink, and / or forward traffic channel.

[0063] The term “network entity” or “base station” (e.g., with an aggregated / sliced base station architecture or a disaggregated base station architecture) can refer to a single physical transmission-reception point (TRP) or multiple physical transmission-reception points (TRPs), which can or can not be co-located. For example, where the term “network entity” or “base station” refers to a single physical TRP, the physical TRP can be a base station antenna corresponding to a cell (or several cell sectors) of the base station. Where the term “network entity” or “base station” refers to multiple co-located physical TRPs, the physical TRPs can be an array of antennas of the base station (e.g., as in a multiple-input multiple-output (MIMO) system or where the base station employs beamforming). Where the term “base station” refers to multiple non-co-located physical TRPs, the physical TRPs can be a distributed antenna system (DAS) (a network of spatially separated antennas connected to a common source via transmission medium) or remote radio heads (RRHs) (remote base stations connected to a serving base station). Alternatively, the non-co-located physical TRPs can be the serving base station that receives the measurement report from the UE and a neighbor base station whose reference radio frequency (RF) signals (or simply “reference signals”) the UE is measuring. Because, as used herein, a TRP is the point from or to which a base station transmits and receives wireless signals, references to transmitting from or receiving at a base station should be understood to refer to particular TRPs of the base station.

[0064] In some implementations that support positioning of UEs, a network entity or base station can not support wireless access by UEs (e.g., can not support data, voice, and / or signaling connections with UEs), but instead can transmit reference signals to UEs to be measured by the UEs, and / or can receive and measure signals transmitted by UEs. Such a base station can be referred to as a positioning beacon (e.g., where it transmits signals to UEs) and / or as a location measurement unit (e.g., where it receives and measures signals from UEs).

[0065] An RF signal includes an electromagnetic wave of a given frequency that transports information through the space between a transmitter and a receiver. As used herein, a transmitter can transmit a single “RF signal” or multiple “RF signals” to a receiver. However, due to the propagation characteristics of RF signals through multipath channels, the receiver can receive multiple “RF signals” corresponding to each transmitted RF signal. The same transmitted RF signal on different paths between the transmitter and receiver can be referred to as a “multipath” RF signal. As used herein, where it is clear from the context that the term “signal” refers to a wireless signal or an RF signal, an RF signal can also be referred to as a “wireless signal” or simply a “signal.”

[0066] According to various aspects, Figure 1An exemplary wireless communications system 100 that can employ the disclosed systems and techniques for enhancements to DDM MIMO sensing based on Doppler spectrum puncturing described herein is illustrated. The wireless communications system 100, which can also be referred to as a wireless wide area network (WW AN), can include various base stations 102 and various UEs 104. In some aspects, a base station 102 can also be referred to as a “network entity” or “network node.” One or more of base stations 102 can implement in an aggregated or monolithic base station architecture. Additionally, or alternatively, one or more of base stations 102 can implement in a disaggregated base station architecture, and can include one or more of a central unit (CU), a distributed unit (DU), a radio unit (RU), a near real-time (near-RT) RIC, or a non-RT RIC. Base stations 102 can include macro cell base stations (high power cellular base stations) and / or small cell base stations (low power cellular base stations). In one aspect, macro cell base stations can include eNBs and / or ng-eNBs (where the wireless communications system 100 corresponds to a Long-Term Evolution (LTE) network), or gNBs (where the wireless communications system 100 corresponds to a NR network), or a combination of both, and small cell base stations can include femto cells, pico cells, micro cells, and the like.

[0067] The base stations 102 can collectively form a RAN and interface with a core network 170 (e.g., an evolved packet core (EPC) or 5G core (5GC)) through backhaul links 122, and with one or more location servers 172 (which can be part of core network 170 or can be external to core network 170) through core network 170. The base stations 102 can perform functions such as transmitting pages to UEs 104, handover, scheduling, enforcing a power control setting, managing mobility, and the like. The base stations 102 can also perform functions such as radio channel encryption / decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, RAN sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations 102 can communicate with each other directly or indirectly (e.g., through the EPC or 5GC) via backhaul links 134, which can be wired or wireless.

[0068] The base stations 102 can wirelessly communicate with the UEs 104. Each of the base stations 102 can provide communication coverage for a respective geographic coverage area 110. In an aspect, a base station 102 in each coverage area 110 can support one or more cells, A “cell” is a logical communication entity for a

[0069] Although the geographic coverage area 110 for each base station 102 can overlap in some areas, the overlap can be variable and even highly variable depending on mter-cell interference. The coverage areas 110 for the base stations 102 can collectively cover a fully or partially populated geographic area, such as a city, a rural area, or an area with a combination of urban and rural environments.

[0070] The communication links 120 between the base stations 102 and the UEs 104 can include uplink (also referred to as reverse link) transmissions from a UE 104 to a base station 102 and / or downlink (also referred to as forward link) transmissions from a base station 102 to a UE 104. The communication links 120 can use MIMO antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. The communication links 120 can be through one or more carrier frequencies. Allocation of carriers can be asymmetric with respect to downlink and uplink (e.g., more or less carriers can be allocated for downlink than for uplink).

[0071] The wireless communications system 100 can further include a WLAN AP 150 in communication with WLAN stations (STAs) 152 via communication link 154 in an unlicensed frequency spectrum (e.g., 5 gigahertz (GHz)). When communicating in an unlicensed frequency spectrum, the WLAN STAs 152 and / or the WLAN AP 150 can perform a clear channel assessment (CCA) or listen before talk (LBT) procedure prior to communicating in order to determine whether the channel is available. In some examples, the wireless communications system 100 can include a device (e.g., a UE, etc.) that utilizes an ultra- wideband (UWB) frequency spectrum to communicate with one or more of the UEs 104, base stations 102, AP 150, etc. The UWB frequency spectrum can range from 3.1 GHz to 10.5 GHz.

[0072] The small cell base stations 102' can operate in a licensed and / or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell base stations 102' can employ LTE or NR technology and use the same 5 GHz unlicensed frequency spectrum as do the WLAN APs 150. The small cell base stations 102' employing LTE and / or 5G in an unlicensed frequency spectrum can boost coverage and / or increase capacity for accessing the network. NR in unlicensed spectrum can be referred to as NR-U. LTE in unlicensed spectrum can be referred to as LTE-U, License Assisted Access (LAA), or MulteFire.

[0073] The wireless communications system 100 can also include millimeter wave (mmW) base stations 180 that can operate in mmW frequencies and / or near mmW frequencies in communication with mmW-enabled UEs 182. The mmW base stations 180 can be implemented in an aggregated or monolithic base station architecture, or alternatively, in a disaggregated base station architecture (e.g., including one or more of a CU, DU, RU, near RT RIC, or non-RT RIC). Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and wavelengths

[0074] Transmit beamforming is a technique used to focus the transmitted RF signal in a specific direction. Traditionally, when a network node or entity (e.g., a base station) broadcasts an RF signal, it broadcasts the signal in all directions (omni-directionally). With transmit beamforming, the network node determines where a given target device (e.g., a UE) is located (relative to the transmitting network node) and projects a stronger downlink RF signal in that specific direction, thereby providing a faster and stronger RF signal (in terms of data rate) for the receiving device. To change the directionality of the RF signal when transmitting, the network node can control the phase and relative amplitude of the RF signal at each of the one or more transmitters that are broadcasting the RF signal. For example, a network node can use an array of antennas (referred to as a “phased array” or “antenna array”), which in effect moves the beam without moving the actual antennas. Specifically, the RF current from the transmitter is fed to the individual antennas with the correct phase relationship so that the radio waves from the separate antennas add together to increase the radiation in a desired direction, while cancelling to suppress radiation in undesired directions.

[0075] Transmit beams can be quasi co-located, which means that they have the same parameters for a receiver (e.g., a UE), regardless of whether the network node’s transmit antennas themselves are physically co-located. In NR, there are four types of quasi co-location (QCL) relationships. Specifically, a given type of QCL relationship means that certain parameters about a second reference RF signal on a second beam can be derived from information about a source reference RF signal on a source beam. Thus, if the source reference RF signal is QCL Type A, then a receiver can use the source reference RF signal to estimate the Doppler shift, Doppler spread, average delay, and delay spread of the second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type B, then a receiver can use the source reference RF signal to estimate the Doppler shift and Doppler spread of the second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type C, then a receiver can use the source reference RF signal to estimate the Doppler shift and average delay of the second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type D, then a receiver can use the source reference RF signal to estimate the spatial receive parameter of the second reference RF signal transmitted on the same channel.

[0076] In receive beamforming, a receiver uses a receive beam to amplify an RF signal detected on a given channel. For example, the receiver can increase a gain setting and / or adjust a phase setting of an antenna array in a particular direction to amplify (e.g., increase a gain level of) an RF signal received from that direction. As such, when a receiver is said to be beamformed in a certain direction, this means that the beam gain in that direction is higher relative to the beam gain along other directions, or that the beam gain in that direction is the highest relative to the beam gains of other beams available to the receiver. This results in a stronger received signal strength (e.g., reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to-interference-plus-noise ratio (SINR), etc.) of the RF signal received from that direction.

[0077] A receive beam can be spatially related. Spatially related means that parameters for a transmit beam for a second reference signal can be derived from information about a receive beam for a first reference signal. For example, a UE can receive one or more reference downlink reference signals (e.g., positioning reference signals (PRSs), tracking reference signals (TRSs), phase tracking reference signals (PTRSs), cell-specific reference signals (CRSs), channel state information reference signals (CSI-RSs), primary synchronization signals (PSSs), secondary synchronization signals (SSSs), synchronization signal blocks (SSBs), etc.) from a network node or entity (e.g., a base station) using a particular receive beam. The UE can then form a transmit beam based on parameters of the receive beam for transmitting one or more uplink reference signals (e.g., uplink positioning reference signals (UL-PRSs), sounding reference signals (SRSs), demodulation reference signals (DMRSs), PTRSs, etc.) to the network node or entity (e.g., base station).

[0078] Note that depending on the entity forming the “downlink” beam, the beam can be a transmit beam or a receive beam. For example, if a network node or entity (e.g., a base station) is forming a downlink beam to transmit a reference signal to a UE, the downlink beam is a transmit beam. However, if a UE is forming a downlink beam, the downlink beam is a receive beam to receive a downlink reference signal. Similarly, depending on the entity forming the “uplink” beam, the beam can be a transmit beam or a receive beam. For example, if a network node or entity (e.g., a base station) is forming an uplink beam, the uplink beam is an uplink receive beam, while if a UE is forming an uplink beam, the uplink beam is an uplink transmit beam.

[0079] In 5G, the frequency spectrum in which wireless network nodes or entities (e.g., base stations 102 / 180, UEs 104 / 182) operate is divided into multiple frequency ranges: FR1 (from 450 megahertz (MHz) to 6000 MHz), FR2 (from 24250 MHz to 52600 MHz), FR3 (above 52600 MHz), and FR4 (between FR1 and FR2). In a multi-carrier system such as 5G, one of the carrier frequencies is referred to as the “primary carrier” or “anchor carrier” or “primary serving cell” or “PCell,” and the remaining carrier frequencies are referred to as “secondary carriers” or “secondary serving cells” or “SCells.” In carrier aggregation, the anchor carrier is the carrier operating on the primary frequency (e.g., FR1) used by the UE 104 / 182 and the cell in which the UE 104 / 182 performs an initial radio resource control (RRC) connection establishment procedure or initiates a RRC connection reestablishment procedure. The primary carrier carries all common and UE-specific control channels, and can be a carrier in a licensed frequency (although this is not always the case). The secondary carrier is a carrier operating on a second frequency (e.g., FR2) that can be configured and can be used to provide additional radio resources once an RRC connection is established between the UE 104 and the anchor carrier. In some cases, the secondary carrier can be a carrier in an unlicensed frequency. The secondary carrier can contain only necessary signaling information and signals, e.g., those that are UE-specific can not be present in the secondary carrier since both the primary uplink and primary downlink carriers are typically UE-specific. This means that different UEs 104 / 182 in a cell can have different downlink primary carriers. The same is true for the uplink primary carrier. The network is able to change the primary carriers of any UE 104 / 182 at any time. This is done, for example, to balance the load on different carriers. Since a “serving cell” (whether a PCell or an SCell) corresponds to a carrier frequency or component carrier that some base station is using to communicate, the terms “cell,” “serving cell,” “component carrier,” “carrier frequency,” etc. can be used interchangeably.

[0080] For example, still referring to Figure 1One of the frequencies used by a macrocell base station 102 can be an anchor carrier (or "PCell"), and other frequencies used by the macrocell base station 102 and / or mmW base station 180 can be secondary carriers ("SCells"). In carrier aggregation, a base station 102 and / or UE 104 can use spectrum up to Y MHz (e.g., 5 MHz, 10 MHz, 15 MHz, 20 MHz, 100 MHz) bandwidth per carrier, with up to a total of Yx MHz x component carriers in each direction used for transmission. The component carriers can or can not be adjacent to each other on the frequency spectrum. The allocation of carriers can be asymmetric with respect to the downlink and uplink (e.g., more or less carriers can be allocated for the downlink than for the uplink). Simultaneous transmission and / or reception of multiple carriers enables a UE 104 / 182 to significantly increase its data transmission and / or reception rates. For example, two 20 MHz aggregated carriers in a multi-carrier system theoretically double the data rate (i.e., 40 MHz) as compared to a single 20 MHz carrier.

[0081] To operate on multiple carrier frequencies, a base station 102 and / or UE 104 is equipped with multiple receivers and / or transmitters. For example, a UE 104 can have two receivers, "Receiver 1" and "Receiver 2," where "Receiver 1" is a multi-band receiver that can be tuned to frequency band (i.e., carrier frequency) "X" or frequency band "Y," and "Receiver 2" is a single-band receiver that can be tuned to only frequency band "Z." In this example, if the UE 104 is being served in frequency band "X," frequency band "X" would be referred to as the PCell or active carrier frequency, and "Receiver 1" would need to be tuned from frequency band "X" to frequency band "Y" (SCell) to measure frequency band "Y" (and vice versa). By contrast, whether the UE 104 is being served in frequency band "X" or frequency band "Y," the UE 104 can measure frequency band "Z" without interrupting service on frequency band "X" or frequency band "Y" due to the separate "Receiver 2."

[0082] The wireless communications system 100 can further include UE 164 that can communicate with macrocell base station 102 on a communication link 120 and / or mmW base station 180 on a mmW communication link 184. For example, the macrocell base station 102 can support a PCell and one or more SCells for the UE 164, and the mmW base station 180 can support one or more SCells for the UE 164.

[0083] The wireless communications system 100 can also include one or more UEs, such as UE 190, that indirectly connect to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links (referred to as “sidelinks”). In Figure 1 In an example, the UE 190 has a D2D P2P link 192 with one of the UEs 104 connected to one of the base stations 102 (e.g., through which the UE 190 can indirectly obtain cellular connectivity), and has a D2D P2P link 194 with WLAN STA 152 connected to the WLAN AP 150 (through which the UE 190 can indirectly obtain WLAN-based Internet connectivity). In an example, the D2D P2P links 192 and 194 can be supported with any well-known D2D RAT (such as LTE Direct (LTE-D), Wi-Fi Direct (Wi-Fi-D), Bluetooth, etc.). As mentioned above, the UEs 104 and 190 can be configured to communicate using sidelink communication. In some cases, a sidelink transmission can include a request for feedback from a receiving UE (e.g., a hybrid automatic repeat request (HARQ)). ® In some cases, a sidelink transmission can include a request for feedback from a receiving UE (e.g., a hybrid automatic repeat request (HARQ)).

[0084] Figure 2 is a diagram illustrating an example of a disaggregated base station architecture that can be employed by the disclosed systems and techniques for enhancements to DDM MIMO sensing based on Doppler spectrum puncturing. Deployments of communication systems, such as 5G NR systems, can be arranged in a variety of ways with various components or constituent parts. In a 5G NR system or network, a network node, network entity, mobility element of a network, radio access network (RAN) node, core network node, network element, or network equipment, such as a base station (BS), or one or more elements (or one or more components) performing base station functionality, can be implemented in an aggregated or disaggregated architecture. For example, a BS, such as a Node B (NB), an evolved NB (eNB), an NR BS, a 5G NB, an AP, a transmission reception point (TRP), or a cell, etc., can be implemented as an aggregated base station (also referred to as a standalone BS or monolithic BS) or a disaggregated base station.

[0085] A disaggregated base station can be configured to utilize a radio protocol stack that is physically or logically integrated within a single RAN node. A disaggregated base station can be configured to utilize a protocol stack that is physically or logically distributed across two or more units, such as one or more central or centralized units (CUs), one or more distributed units (DUs), or one or more radio units (RUs). In some aspects, a CU can be implemented within a RAN node, and one or more DUs can be co-located with the CU, or alternatively, can be geographically or virtually distributed in one or more other RAN nodes. The DUs can be implemented to be in communication with one or more RUs. Each of the CU, DU, and RU can also be implemented as virtual units, i.e., a virtual central unit (VCU), virtual distributed unit (VDU), or virtual radio unit (VRU).

[0086] Base station type operations or network designs can take into account the disaggregated nature of base station functionality. For example, a disaggregated base station can be utilized in an integrated access backhaul (IAB) network, an open radio access network (O-RAN (such as network configurations initiated by the O-RAN Alliance)), or a virtualized radio access network (vRAN, also referred to as a cloud radio access network (C-RAN)). Disaggregation can include distributing functionality across two or more units at various physical locations, as well as virtually distributing functionality of at least one unit, which can enable flexibility in network design. The various units of a disaggregated base station or disaggregated RAN architecture can be configured for wired or wireless communication with at least one other unit.

[0087] As previously mentioned, Figure 2 An illustration diagram is shown that illustrates an example disaggregated base station 201 architecture. The disaggregated base station 201 architecture can include one or more central units (CUs) 211 that can communicate directly with a core network 223 via a backhaul link, or indirectly through one or more disaggregated base station units, such as a near real-time (near-RT) RAN intelligent controller (RIC) 227 via an E2 link, or a non-real-time (non-RT) RIC 217 associated with a service management and orchestration (SMO) framework 207, or both. The CUs 211 can be in communication with one or more distributed units (DUs) 231 via respective fronthaul links, such as Fl interfaces. The DUs 231 can be in communication with one or more radio units (RUs) 241 via respective front-haul links. The RUs 241 can be in communication with respective UEs 221 via one or more RF access links. In some implementations, a UE 221 can be simultaneously served by multiple RUs 241.

[0088] Each of the units (i.e., CU 211, DU 231, RU 241, and near-RT RIC 227, non-RT RIC 217, and SMO framework 207) can include or be coupled to one or more interfaces configured to receive or transmit signals, data, or information (collectively, signals) via wired or wireless transmission media. Each of the units, or an associated processor or controller providing instructions to the communication interfaces of these units, can be configured to communicate with one or more of the other units via the transmission media. For example, the units can include wired interfaces configured to receive or transmit signals to one or more of the other units over a wired transmission medium. Additionally, the units can include wireless interfaces, which can include receivers, transmitters, or transceivers (such as RF transceivers) configured to receive or transmit signals to one or more of the other units over a wireless transmission medium, or both.

[0089] In some aspects, the CU 211 can host one or more higher layer control functions. Such control functions can include radio resource control (RRC), packet data convergence protocol (PDCP), service data adaptation protocol (SDAP), etc. Each control function can utilize an interface configured to communicate signals with other control functions hosted by the CU 211. The CU 211 can be configured to handle user plane functionality (i.e., central unit-user plane (CU-UP)), control plane functionality (i.e., central unit-control plane (CU-CP)), or a combination thereof. In some implementations, the CU 211 can be logically split into one or more CU-UP units and one or more CU-CP units. When implemented in an O-RAN configuration, the CU-UP units can communicate bi-directionally with the CU-CP units via an interface, such as an El interface. The CU 211 can be implemented to communicate with the DU 231 as needed for network control and signaling.

[0090] The DU 231 can correspond to a logical unit that includes one or more base station functions for controlling operation of one or more RUs 241. In some aspects, the DU 231 can host one or more of a radio link control (RLC) layer, a medium access control (MAC) layer, and one or more high physical (PHY) layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, etc.) in accordance with, at least in part, a functional split, such as those defined by the 3rd Generation Partnership Project (3GPP). In some aspects, the DU 231 can also host one or more low PHY layers. Each layer (or module) can be implemented with an interface configured to communicate signals with other layers (and modules) hosted by the DU 231 or with control functions hosted by the CU 211.

[0091] Lower layer functionality can be implemented by one or more RUs 241. In some deployments, the RUs 241 controlled by the DU 231 can correspond to logical nodes that host RF processing functions or low PHY layer functions (such as performing fast Fourier transform (FFT), inverse FFT (iFFT), digital beamforming, physical random access channel (PRACH) extraction and filtering, etc.), or both, based at least in part on a functional split, such as a lower layer functional split. In such an architecture, the RUs 241 can be implemented to handle over-the-air (OTA) communications with one or more UEs 221. In some implementations, real-time and non-real-time aspects of control plane and user plane communications with the RUs 241 can be controlled by the corresponding DU 231. In some scenarios, this configuration can enable the DUs 231 and CUs 211 to be implemented in a cloud-based RAN architecture, such as a vRAN architecture.

[0092] The SMO framework 207 can be configured to support RAN deployment and orchestration of non-virtualized network elements and virtualized network elements. For non- virtualized network elements, the SMO framework 207 can be configured to support deployment of dedicated physical resources for RAN coverage requirements, which can be managed via an operations and maintenance interface, such as an Ol interface. For virtualized network elements, the SMO framework 207 can be configured to interact with a cloud computing platform, such as Open Cloud (O-Cloud) 291, to perform network element lifecycle management, such as to instantiate virtualized network elements, via a cloud computing platform interface, such as an 02 interface. Such virtualized network elements can include, but are not limited to, CUs 211, DUs 231, RUs 241, and near-RT RICs 227. In some implementations, the SMO framework 207 can communicate with hardware aspects of a 4G RAN, such as Open eNB (O-eNB) 213, via an Ol interface. Additionally, in some implementations, the SMO framework 207 can communicate directly with one or more RUs 241 via an Ol interface. The SMO framework 207 can also include a non-RT RIC 217 configured to support functionality of the SMO framework 207.

[0093] The non-RT RIC 217 can be configured to include logical functions that enable near real-time control and optimization of RAN elements and resources, artificial intelligence / machine learning (AI / ML) workflows including model training and update, or policy-based direction of applications / features in the near-RT RIC 227. The non-RT RIC 217 can be coupled to, or in communication with, the near-RT RIC 227, such as via an Al interface. The near-RT RIC 227 can be configured to include logical functions that enable near real-time control and optimization of RAN elements and resources via data collection and actions via an interface, such as via an E2 interface, that connects one or more CUs 211, one or more DUs 231, or both, and the O-eNB 213 with the near-RT RIC 227.

[0094] In some implementations, to generate AI / ML models to be deployed in near-RT RIC 227, non-RT RIC 217 can receive parameters or external enrichment information from an external server. Such information can be utilized by near-RT RIC 227 and can be received at SMO framework 207 or non-RT RIC 217 from non-network data sources or from network functions. In some examples, non-RT RIC 217 or near-RT RIC 227 can be configured to tune RAN behavior or performance. For example, non-RT RIC 217 can monitor long-term trends and patterns of performance and employ AI / ML models to perform corrective actions through SMO framework 207, such as via reconfiguration of Ol, or via creation of RAN management policies, such as Al policies.

[0095] Various radio frame structures can be used to support downlink, uplink, and sidelink transmissions between network nodes (e.g., base stations and UEs). Figure 3 is a diagram 300 illustrating an example of a frame structure that can be employed by the disclosed systems and techniques for enhancements to DDM MIMO sensing based on Doppler spectrum puncturing. Other wireless communication technologies can have different frame structures and / or different channels.

[0096] NR (and LTE) utilizes OFDM on the downlink and uses single-carrier frequency division multiplexing (SC-FDM) on the uplink. In contrast to LTE, however, NR has the option of using OFDM on the uplink as well. OFDM and SC-FDM partition the system bandwidth into multiple (K) orthogonal subcarriers, which are often referred to as tones, bins, etc. Each subcarrier can be modulated with data. In general, modulation symbols are sent in the frequency domain with OFDM and in the time domain with SC-FDM. The spacing of the adjacent subcarriers can be fixed, and the total number of subcarriers (K) can be dependent on the system bandwidth. For example, the spacing of the subcarriers can be 15 kHz and the minimum resource allocation (called a “resource block” (RB)) can be 12 subcarriers (or 180 kHz). Consequently, for a 1.25, 2.5, 5, 10, or 20 megahertz (MHz) system bandwidth, the nominal fast Fourier transform (FFT) size can be equal to 128, 256, 512, 1024, or 2048, respectively. The system bandwidth can also be partitioned into subbands. For example, a subband can cover 1.08 MHz (i.e., 6 resource blocks), and there can be 1, 2, 4, 8, or 16 subbands for a 1.25, 2.5, 5, 10, or 20 MHz system bandwidth, respectively.

[0097] LTE supports a single numerology (subcarrier spacing, symbol length, etc.). In contrast, NR can support multiple numerologies (µ). For example, subcarrier spacing (SCS) of 15 kHz, 30 kHz, 60 kHz, 120 kHz, and 240 kHz or greater can be available. Table 1, provided below, lists some of the different parameters for different NR numerologies.

[0098]

[0099] Table 1

[0100] In one example, a numerology of 15 kHz is used. Thus, in the time domain, a 10 millisecond (ms) frame is divided into 10 equal sized subframes, each of 1 ms, and each subframe includes one slot. In the frequency domain, each slot contains a number of resource blocks (RBs) that are located with the carrier. Figure 3 In the drawings, time is represented in the horizontal direction (e.g., on the X-axis), where time increases from left to right, and frequency is represented in the vertical direction (e.g., on the Y-axis), where frequency increases (or decreases) from bottom to top.

[0101] A resource grid can be used to represent the time slots, each time slot including one or more time-concurrent resource blocks (RBs) (also referred to as physical RBs (PRBs)) in the frequency domain. Figure 3 An example of a resource block (RB) 302 is illustrated. Data or information for joint communication and sensing can be included in one or more RBs 302. The RB 302 is arranged by placing the time domain on the horizontal (or x) axis and the frequency domain on the vertical (or y) axis. As shown, the RB 302 can be 180 kilohertz (kHz) wide in frequency and one slot long in time (where a slot is 1 millisecond (ms) in time). In some cases, a slot can include fourteen symbols (e.g., in slot configuration 0). The RB 302 includes twelve subcarriers (along the y-axis) and fourteen symbols (along the x-axis).

[0102] The intersection of a symbol and a subcarrier can be referred to as a resource element (RE) 304 or tone. Figure 3 The RB 302 includes a number of REs, including resource elements (REs) 304. For example, an RE 304 is 1 subcarrier x 1 symbol (e.g., OFDM symbol) and is the smallest discrete part of a subframe. An RE 304 includes a single complex value representing data from a physical channel or signal. The number of bits carried by each RE 304 depends on the modulation scheme.

[0103] In some aspects, some of the REs 304 can be used for transmitting downlink reference (pilot) signals (DL-RS). The DL-RS can include positioning reference signals (PRS), tracking reference signals (TRS), phase tracking reference signals (PTRS), channel state information reference signals (CSI-RS), demodulation reference signals (DMRS), primary synchronization signals (PSS), secondary synchronization signals (SSS), etc. Figure 3 An example location of REs 304 used for transmitting DL-RS (labeled “R”) is illustrated for a resource grid of 1 resource block by 1 symbol.

[0104] Figure 4 is a block diagram illustrating an example of a computing system 470 of an electronic device 407 that can be employed by the disclosed systems and techniques for enhancements to DDM MIMO sensing based on Doppler spectrum puncturing. The electronic device 407 is an example of a device that can include hardware and software for connecting and exchanging data with other devices and systems using a communication network (e.g., a third generation partnership network, such as a fifth generation (5G) / New Radio (NR) network, a fourth generation (4G) / Long Term Evolution (LTE) network, a WiFi network, or other communication network). For example, the electronic device 407 can comprise or be part of a mobile device (e.g., a mobile phone), a wearable device (e.g., a network-connected or smart watch), an extended reality device (e.g., a virtual reality (VR) device, an augmented reality (AR) device, or a mixed reality (MR) device), a personal computer, a laptop computer, a tablet computer, an Internet of Things (IoT) device, a wireless access point, a router, a vehicle or component of a vehicle, a server computer, a robotic device, and / or other device used by a user to communicate over a wireless communication network. In some cases, such as when referring to a device configured to communicate using a 5G / NR, 4G / LTE, or other telecommunication standard, the device 407 can be referred to as a user equipment (UE). In some cases, such as when referring to a device configured to communicate using a Wi-Fi standard, the device can be referred to as a station (STA).

[0105] The computing system 470 includes software and hardware components that can be electrically or communicatively coupled (or can otherwise communicate), as appropriate, via bus 489. For example, the computing system 470 includes one or more processors 484. The one or more processors 484 can include one or more CPUs, ASICs, FPGAs, APs, GPUs, VPU, NSP, microcontrollers, specialized hardware, any combination thereof, and / or other processing devices and / or systems. The bus 489 can be used by the one or more processors 484 to communicate with each other and / or with one or more memory devices 486.

[0106] The computing system 470 can also include one or more memory devices 486, one or more digital signal processors (DSPs) 482, one or more subscriber identity modules (SIMs) 474, one or more modems 476, one or more wireless transceivers 478, one or more antennas 487, one or more input devices 472 (e.g., a camera, a mouse, a keyboard, a touch-sensitive screen, a touchpad, a keypad, a microphone or microphone array, etc.), and one or more output devices 480 (e.g., a display, a speaker, a printer, etc.).

[0107] The one or more wireless transceivers 478 can receive wireless signals (e.g., signals 488) from one or more other devices such as other user devices, network devices (e.g., base stations such as evolved Node Bs (eNBs) and / or gNodeBs (gNBs), WiFi access points (APs) such as routers, range extenders, etc.), cloud networks, etc. via the antennas 487. In some examples, the computing system 470 can include multiple antennas or antenna arrays that can facilitate simultaneous transmit and receive functionality. The antennas 487 can be omnidirectional, such that RF signals can be received from and sent to in all directions. The wireless signals 488 can be sent via a wireless network. The wireless network can be any wireless network, such as a cellular or telecommunication network (e.g., 3G, 4G, 5G, etc.), a wireless local area network (e.g., a WiFi network), a Bluetooth network, a near-field communication (NFC) network, a local area network (LAN), a metropolitan area network (MAN), a telephone network, a wide area network (WAN), and / or other networks. ™ In some examples, the one or more wireless transceivers 478 can include an RF front end that includes one or more components such as amplifiers, mixers (also referred to as signal multipliers) for down-converting a frequency of a signal, frequency synthesizers (also referred to as oscillators) that provide frequencies to the mixers, baseband filters, analog-to-digital converters (ADCs), one or more power amplifiers, and other components. The RF front end can generally handle selection of the wireless signals 488 and conversion of that wireless signal to baseband or an intermediate frequency, and can convert RF signals to the digital domain.

[0108] In some cases, the computing system 470 can include a coding-decoding device (or codec) configured to encode and / or decode data transmitted and / or received using the one or more wireless transceivers 478. In some cases, the computing system 470 can include an encryption-decryption device or component configured to encrypt and / or decrypt data transmitted and / or received by the one or more wireless transceivers 478 (e.g., according to Advanced Encryption Standard (AES) and / or Data Encryption Standard (DES) standards).

[0109] The one or more SIMs 474 can each securely store an International Mobile Subscriber Identity (IMSI) number and related key, which are assigned to a subscriber of the electronic device 407. The IMSI and key can be used to identify and authenticate the subscriber when accessing networks provided by network service providers or operators associated with the one or more SIMs 474. The one or more modems 476 can modulate one or more signals to encode information for transmission using the one or more wireless transceivers 478. The one or more modems 476 can also demodulate signals received by the one or more wireless transceivers 478 in order to decode information transmitted. In some examples, the one or more modems 476 can include a WiFi modem, a 4G (or LTE) modem, a 5G (or NR) modem, and / or other types of modems. The one or more modems 476 and the one or more wireless transceivers 478 can be used to communicate data for the one or more SIMs 474.

[0110] The computing system 470 can also include (and / or be in communication with) one or more non-transitory machine-readable storage media (e.g., one or more memory devices 486) 486, which can include, among others, local and / or network accessible storage, a disk drive, a drive array, an optical storage device, a solid-state storage device, such as a RAM and / or ROM, which can be programmable, flash- updateable, and / or the like. Such storage devices can be configured to implement any appropriate data stores, including without limitation, various file systems, database structures, and / or the like.

[0111] In various aspects, functionality can be stored as one or more computer programs (e.g., instructions or code) in the memory device(s) 486 and executed by the one or more processors 484 and / or the one or more DSPs 482. The computing system 470 can further include software elements (e.g., in the one or more memory devices 486), including without limitation an operating system, device drivers, executable libraries, and / or other code, such as one or more application programs, which can include computer programs provided by various aspects, and / or can be designed to implement methods, and / or configure systems, as described herein.

[0112] In some aspects, the electronic device 407 can include means for performing the operations described herein. The means can include one or more components of the computing system 470. For example, the means for performing the operations described herein can include one or more of the input device 472, the SIM 474, the modem 476, the wireless transceiver 478, the output device 480, the DSP 482, the processor 484, the memory device 486, and / or the antenna 487.

[0113] In some aspects, the electronic device 407 can include means for providing joint communication and sensing and means for enhancing Doppler spectrum based punctured DDM MIMO sensing, for example, when multiplexing sensing and communication signals for joint communication and sensing (JCS). In some examples, any or all of the means can include the one or more wireless transceivers 478, the one or more modems 476, the one or more processors 484, the one or more DSPs 482, the one or more memory devices 486, any combination thereof, or other components of the electronic device 407.

[0114] Figure 5 is a diagram illustrating an example of a wireless device 500 that utilizes RF single- station sensing techniques for determining one or more characteristics (e.g., position, velocity or speed, heading, etc.) of a target 502 object. Specifically, Figure 5 is a diagram illustrating an example of a wireless device 500 (e.g., a transmitting / receiving sensing node) that utilizes RF sensing techniques (e.g., single-station sensing) to perform one or more functions, such as detecting the presence and location of a target 502 (e.g., an object, a user, or a vehicle), which is illustrated in the figure in the form of a vehicle.

[0115] In some examples, the wireless device 500 can be a mobile phone, a tablet computer, a wearable device, a vehicle, an extended reality (XR) device, a component of a computing device or vehicle, or other device that includes at least one RF interface (e.g., Figure 4 the electronic device 407). In some examples, the wireless device 500 can be a device that provides connectivity for a user device (e.g., for the electronic device 407), such as a base station (e.g., a gNB, an eNB, etc.), a wireless access point (AP), or other device that includes at least one RF interface. Figure 4 In some examples, the wireless device 500 can be a device that provides connectivity for a user device (e.g., for the electronic device 407), such as a base station (e.g., a gNB, an eNB, etc.), a wireless access point (AP), or other device that includes at least one RF interface.

[0116] In some aspects, the wireless device 500 can include one or more components for transmitting RF signals. The wireless device 500 can include at least one processor 522 for generating a digital signal or waveform. The wireless device 500 can also include a digital-to-analog converter (DAC) 504 that can receive the digital signal or waveform from the processor 522 (e.g., a microprocessor) and convert the digital signal or waveform into an analog waveform. The analog signal that is output from the DAC 504 can be provided to an RF transmitter 506 for transmission. The RF transmitter 506 can be a Wi-Fi transmitter, a 5G / NR transmitter, a Bluetooth transmitter, or any other transmitter capable of transmitting RF signals. ™

[0117] ​RF transmitter 506 may be coupled to one or more transmitting antennas, such as Tx antenna 512. In some examples, transmitting (Tx) antenna 512 may be an omnidirectional antenna capable of transmitting RF signals in all directions. For example, Tx antenna 512 may be an omnidirectional Wi-Fi antenna capable of radiating Wi-Fi signals in a 360-degree radiation pattern (e.g., 2.4 GHz, 5 GHz, 6 GHz, etc.). In another example, Tx antenna 512 may be a directional antenna that transmits RF signals in a specific direction.

[0118] In some examples, the wireless device 500 may also include one or more components for receiving RF signals. For example, the receiver array in the wireless device 500 may include one or more receiving antennas, such as a receive (Rx) antenna 514. In some examples, the Rx antenna 514 may be an omnidirectional antenna capable of receiving RF signals from multiple directions. In other examples, the Rx antenna 514 may be a directional antenna configured to receive signals from a specific direction. In further examples, the Tx antenna 512 and / or the Rx antenna 514 may include multiple antennas (e.g., elements) configured as an antenna array (e.g., a phased antenna array).

[0119] The wireless device 500 may also include an RF receiver 510 coupled to the Rx antenna 514. The RF receiver 510 may include features for receiving RF waveforms such as Wi-Fi signals and Bluetooth signals. ™ One or more hardware components (RF receiver 510, 5G / NR signal, or any other RF signal). The output of RF receiver 510 can be coupled to analog-to-digital converter (ADC) 508. ADC 508 can be configured to convert the received analog RF waveform into a digital waveform. The digital waveform, as the output of ADC 508, can be provided to processor 522 for processing. Processor 522 (e.g., digital signal processor (DSP)) can be configured to process the digital waveform.

[0120] In one example, wireless device 500 can implement an RF sensing technique, e.g., a monostatic sensing technique, by causing Tx waveform 516 to be transmitted from Tx antenna 512. Although Tx waveform 516 is illustrated as a single line, in some cases, Tx waveform 516 can be transmitted in all directions by omni-directional Tx antenna 512. In one example, Tx waveform 516 can be a Wi-Fi waveform transmitted by a Wi-Fi transmitter in wireless device 500. In some cases, Tx waveform 516 can correspond to a Wi-Fi waveform transmitted concurrently or nearly concurrently with a Wi-Fi data communication signal or a Wi-Fi control function signal (e.g., a beacon transmission). In some examples, Tx waveform 516 can be transmitted using the same or similar frequency resources as a Wi-Fi data communication signal or a Wi-Fi control function signal (e.g., beacon transmission). In some aspects, Tx waveform 516 can correspond to a Wi-Fi waveform transmitted separately from a Wi-Fi data communication signal and / or a Wi-Fi control signal (e.g., Tx waveform 516 can be transmitted at a different time and / or using different frequency resources).

[0121] In some examples, Tx waveform 516 can correspond to a 5G NR waveform transmitted concurrently or nearly concurrently with a 5G NR data communication signal or a 5G NR control function signal. In some examples, Tx waveform 516 can be transmitted using the same or similar frequency resources as a 5G NR data communication signal or a 5G NR control function signal. In some aspects, Tx waveform 516 can correspond to a 5G NR waveform transmitted separately from a 5G NR data communication signal and / or a 5G NR control signal (e.g., Tx waveform 516 can be transmitted at a different time and / or using different frequency resources).

[0122] In some aspects, one or more parameters associated with Tx waveform 516 can be modified, which can be used to increase or decrease RF sensing resolution. These parameters can include a frequency, a bandwidth, a number of spatial streams, a number of antennas configured to transmit Tx waveform 516, a number of antennas configured to receive reflected RF signals (e.g., Rx waveform 518) corresponding to Tx waveform 516, a number of spatial links (e.g., a number of spatial streams multiplied by a number of antennas configured to receive RF signals), a sampling rate, or any combination thereof. The transmitted waveforms (e.g., Tx waveform 516) and the received waveforms (e.g., Rx waveform 518) can include one or more RF sensing signals, which are also referred to as radar reference signals (RS).

[0123] In further examples, the Tx waveform 516 can be implemented as a sequence with perfect or nearly perfect autocorrelation properties. For example, the Tx waveform 516 can include a single-carrier Zadoff sequence or can include a symbol similar to an orthogonal frequency-division multiplexing (OFDM) long training field (LTF) symbol. In some cases, the Tx waveform 516 can include a chirp signal as used, for example, in a frequency-modulated continuous-wave (FM-CW) radar system. In some configurations, the chirp signal can include a signal in which the signal frequency is periodically increased and / or decreased in a linear and / or exponential manner.

[0124] In some aspects, the wireless device 500 can implement the RF sensing technique by performing alternating transmit and receive functions (e.g., performing a half-duplex operation). For example, the wireless device 500 can alternately enable its RF transmitter 506 to transmit the Tx waveform 516 when the RF receiver 510 is not enabled to receive (i.e., is not receiving) and enable its RF receiver 510 to receive the Rx waveform 518 when the RF transmitter 506 is not enabled to transmit (i.e., is not transmitting). When the wireless device 500 performs a half-duplex operation, the wireless device 500 can transmit the Tx waveform 516, which can be a radar RS (e.g., a sensing signal).

[0125] In other aspects, the wireless device 500 can implement the RF sensing technique by performing concurrent transmit and receive functions (e.g., performing a sub-band or full-band full-duplex operation). For example, the wireless device 500 can enable its RF receiver 510 to receive at the same time or nearly the same time as it enables the RF transmitter 506 to transmit the Tx waveform 516. When the wireless device 500 performs a full-duplex operation (e.g., a sub-band full-duplex or a full-band full-duplex), the wireless device 500 can transmit the Tx waveform 516, which can be a radar RS (e.g., a sensing signal).

[0126] In some examples, the transmission of the sequence or pattern included in the Tx waveform 516 can be repeated continuously such that the sequence is transmitted a particular number of times or for a particular duration. In some examples, if the RF receiver 510 is enabled after the RF transmitter 506, the repetition of the pattern in the transmission of the Tx waveform 516 can be used to avoid missing the reception of any reflected signals. In one example implementation, the Tx waveform 516 can include a sequence of length L that is transmitted two or more times, which can allow the RF receiver 510 to be enabled for less than or equal to L time in order to receive the reflections corresponding to the entire sequence without missing any information.

[0127] By implementing alternating or simultaneous transmit and receive functionality (e.g., half-duplex or full-duplex operation), the wireless device 500 can receive signals corresponding to the Tx waveform 516. For example, the wireless device 500 can receive signals reflected from objects or people within a range of the Tx waveform 516, such as the Rx waveform 518 reflected from the target 502. The wireless device 500 can also receive a leakage signal (e.g., Tx leakage signal 520) that couples directly from the Tx antenna 512 to the Rx antenna 514 without reflecting from any object. For example, the leakage signal can include a signal that passes from a transmitter antenna (e.g., the Tx antenna 512) on the wireless device to a receive antenna (e.g., the Rx antenna 514) on the wireless device without reflecting from any object. In some cases, the Rx waveform 518 can include multiple sequences corresponding to multiple copies of the sequence included in the Tx waveform 516. In some examples, the wireless device 500 can combine multiple sequences received by the RF receiver 510 to improve a signal-to-noise ratio (SNR).

[0128] The wireless device 500 can also implement RF sensing techniques by obtaining RF sensing data associated with each of the received signals corresponding to the Tx waveform 516. In some examples, the RF sensing data can include channel state information (CSI) data related to a direct path (e.g., the leakage signal 520) of the Tx waveform 516 and data related to reflected paths (e.g., the Rx waveform 518) corresponding to the Tx waveform 516.

[0129] In some aspects, the RF sensing data (e.g., CSI data) can include information that can be used to determine a manner in which an RF signal (e.g., the Tx waveform 516) propagates from the RF transmitter 506 to the RF receiver 510. The RF sensing data can include data corresponding to an impact on a transmitted RF signal due to scattering, fading, and / or power decay with distance, or any combination thereof. In some examples, the RF sensing data can include complex data corresponding to each tone in a frequency domain over a particular bandwidth (e.g., I / Q components).

[0130] In some examples, the RF sensing data can be used by the processor 522 to compute a distance and an angle of arrival corresponding to a reflected waveform, such as the Rx waveform 518. In further examples, the RF sensing data can also be used to detect motion, determine a location, detect a change in a location or a motion pattern, or any combination thereof. In some cases, the distance and angle of arrival of a reflected signal can be used to identify a size, a location, a movement, and / or an orientation of a target (e.g., the target 502) in a surrounding environment in order to detect a target presence / proximity.

[0131] The processor 522 of the wireless device 500 can calculate the range and angle of arrival corresponding to the reflected waveform (e.g., the range and angle of arrival corresponding to the Rx waveform 518) by utilizing signal processing, machine learning algorithms, any other suitable technique, or any combination thereof. In other examples, the wireless device 500 can transmit or communicate the RF sensing data to at least one processor of another computing device, such as a server or a base station, which can perform the calculations to obtain the range and angle of arrival corresponding to the Rx waveform 518 or other reflected waveforms.

[0132] In one example, the range of the Rx waveform 518 can be calculated by measuring the time difference from receiving the leaky signal to receiving the reflected signal. For example, the wireless device 500 can determine a baseline distance of zero based on the difference between the time at which the Tx waveform 516 is transmitted from the wireless device 500 and the time at which the leaky signal 520 is received by the wireless device 500 (e.g., a propagation delay). The processor 522 of the wireless device 500 can then determine the range associated with the Rx waveform 518 based on the difference between the time at which the Tx waveform 516 is transmitted from the wireless device 500 and the time at which the Rx waveform 518 is received by the wireless device 500 (e.g., a time of flight, which is also referred to as a round trip time (RTT)), and can then adjust the range according to the propagation delay associated with the leaky signal 520. By doing so, the processor 522 of the wireless device 500 can determine the distance traveled by the Rx waveform 518, which can be used to determine the presence and movement of the target (e.g., the target 502) that caused the reflection.

[0133] In further examples, the angle of arrival of the Rx waveform 518 can be calculated by the processor 522 by measuring the time difference of arrival of the Rx waveform 518 between individual elements of a receive antenna array, such as the antennas 514. In some examples, the time difference of arrival can be calculated by measuring the difference in received phase at each element in the receive antenna array.

[0134] In some cases, the range and angle of arrival of the Rx waveform 518 can be used by the processor 522 to determine the distance between the wireless device 500 and the target 502 and the location of the target 502 relative to the wireless device 500. The range and angle of arrival of the Rx waveform 518 can also be used to determine the presence, movement, proximity, identity, or any combination thereof of the target 502. For example, the processor 522 of the wireless device 500 can utilize the calculated range and angle of arrival corresponding to the Rx waveform 518 to determine that the target 502 is moving toward the wireless device 500.

[0135] As mentioned above, the wireless device 500 can comprise a mobile device (e.g., an IoT device, a smartphone, a laptop, a tablet, etc.) or other type of device. In some examples, the wireless device 500 can be configured to obtain device location data and device orientation data as well as RF sensing data. In some cases, the device location data and device orientation data can be used to determine or adjust the range and angle of arrival of reflected signals such as the Rx waveform 518. For example, when the target 502 (e.g., a vehicle) is moving toward the wireless device 500 during an RF sensing process, the wireless device can be set on the ground facing the sky. In this case, the wireless device 500 can use its location data and orientation data as well as the RF sensing data to determine the direction in which the target 502 is moving.

[0136] In some examples, the wireless device 500 can collect device location data using techniques including RTT measurements, time of arrival (TOA) measurements, time difference of arrival (TDOA) measurements, passive positioning measurements, angle of arrival (AOA) measurements, angle of departure (AoD) measurements, received signal strength indicator (RSSI) measurements, CSI data, using any other suitable technique, or any combination thereof. In further examples, device orientation data can be obtained from electronic sensors on the wireless device 500 such as gyroscopes, accelerometers, compasses, magnetometers, barometers, any other suitable sensor, or any combination thereof.

[0137] Figure 6 is a diagram illustrating an example of utilizing a receiver 604 with an RF bistatic sensing technique with one transmitter 600 for determining one or more characteristics (e.g., location, velocity or speed, heading, etc.) of a target 602 object. For example, the receiver 604 can use RF bistatic sensing to detect the presence and location of a target 602 (e.g., an object, a user, or a vehicle) that is in Figure 6 illustrated in the form of a vehicle in

[0138] Figure 6 The bistatic radar system of includes a transmitter 600 (e.g., a transmitting sensing node) and a receiver 604 (e.g., a receiving sensing node), which is depicted in the figure in the form of a base station (e.g., a gNB), that are separated by a distance comparable to the expected target distance. In contrast to the Figure 5 single station system of Figure 6 The transmitter 600 and the receiver 604 of the bistatic radar system of are positioned away from each other. In contrast, a single station radar is one that includes a transmitter (e.g., the RF transmitter 506 of the wireless device 500) and a receiver (e.g., the RF receiver 508 of the wireless device 500) that are co-located with each other. Figure 5 Figure 5 ​The radar system (e.g., the RF receiver 510 of the wireless device 500) Figure 5 (system).

[0139] Bistatic radar (or more generally, multistatic radar with more than one receiver) has the advantage over monostatic radar in that it can collect radar echoes reflected from the scene at an angle different from the angle of the transmitted pulse. This may be of concern to some applications (e.g., transportation applications, scenes with multiple objects, military applications, etc.) where targets can reflect the transmitted energy in many directions (e.g., where targets are specifically designed to reflect in many directions), which minimizes the energy reflected back to the transmitter. It should be noted that in one or more examples, a monostatic system can coexist with a multistatic radar system, such as when the transmitter also has a co-located receiver.

[0140] In some examples, Figure 6 The transmitter 600 and / or receiver 604 may be a mobile phone, tablet computer, wearable device, vehicle, or other device including at least one RF interface (e.g., Figure 4 Device 407). In some examples, transmitter 600 and / or receiver 604 may be user equipment (e.g., device 407). Figure 4 IoT devices (407) provide connectivity, such as base stations (e.g., gNB, eNB, etc.), wireless access points (APs), or other devices that include at least one RF interface.

[0141] In some aspects, transmitter 600 may include one or more components for transmitting RF signals. Transmitter 600 may include at least one processor capable of determining the signals to be transmitted (e.g., determining the waveforms of these signals). Figure 5 At least one processor 522). Transmitter 600 may also include an RF transmitter (e.g., for transmitting a Tx signal including a Tx waveform 616) for transmitting a Tx signal including a Tx waveform 616. Figure 5 RF transmitter 506). The RF transmitter can be a transmitter configured to transmit cellular signals or telecommunications signals (e.g., a transmitter configured to transmit 5G / NR signals, 4G / LTE signals, or other cellular / telecommunications signals), a Wi-Fi transmitter, or a Bluetooth transmitter. ™ Transmitters, any combination thereof, or any other transmitter capable of transmitting RF signals.

[0142] The RF transmitter can be coupled to one or more transmit antennas, such as a Tx antenna (e.g., Figure 5Tx antennas 512). In some examples, the Tx antennas can be omnidirectional antennas that are capable of transmitting RF signals in all directions, or directional antennas that are capable of transmitting RF signals in particular directions. In some examples, the Tx antennas can include multiple antennas (e.g., elements) configured as an antenna array.

[0143] The receiver 604 can also include one or more components for receiving RF signals. For example, the receiver 604 can include one or more receive antennas, such as Rx antennas (e.g., Figure 5 Rx antennas 514). In some examples, the Rx antennas can be omnidirectional antennas that are capable of receiving RF signals from multiple directions, or directional antennas that are configured to receive signals from particular directions. In further examples, the Rx antennas can include multiple antennas (e.g., elements) configured as an antenna array.

[0144] The receiver 604 can also include an RF receiver coupled to the Rx antennas (e.g., Figure 5 RF receiver 510). The RF receiver can include one or more hardware components for receiving RF waveforms, such as Wi-Fi signals, Bluetooth ™ signals, 5G / NR signals, or any other RF signals. The output of the RF receiver can be coupled to at least one processor (e.g., Figure 7 at least one processor 522). The processor can be configured to process the received waveforms (e.g., Rx waveforms 618).

[0145] In one or more examples, the transmitter 600 can implement an RF sensing technique, such as a bistatic sensing technique, by causing the transmission of the Tx waveforms 616 from the Tx antennas. It should be noted that although the Tx waveforms 616 are illustrated as single lines, in some cases, the Tx waveforms 616 can be transmitted in all directions by an omnidirectional Tx antenna.

[0146] In one or more aspects, one or more parameters associated with the Tx waveforms 616 can be used to increase or decrease the RF sensing resolution. These parameters can include a frequency, a bandwidth, a number of spatial streams, a number of antennas configured to transmit the Tx waveforms 616, a number of antennas configured to receive reflected RF signals (e.g., Rx waveforms 618) corresponding to the Tx waveforms 616, a number of spatial links (e.g., a number of spatial streams multiplied by a number of antennas configured to receive RF signals), a sampling rate, or any combination thereof. The transmitted waveforms (e.g., Tx waveforms 616) and the received waveforms (e.g., Rx waveforms 618) can include one or more radar RF sensing signals (also referred to as RF sensing RSs).

[0147] During operation, receiver 604 (e.g., operating as a receiving sensing node) can receive a signal corresponding to Tx waveform 616, which was transmitted by transmitter 600 (e.g., operating as a transmitting sensing node). For example, receiver 604 can receive a signal reflected from an object or person within a range of Tx waveform 616, such as Rx waveform 618 reflected from target 602. In some cases, Rx waveform 618 can include multiple sequences corresponding to multiple copies of the sequence included in Tx waveform 616. In some examples, receiver 604 can combine the multiple sequences received to improve SNR.

[0148] In some examples, at least one processor within receiver 604 can use the RF sensing data to compute a distance, angle of arrival, or other characteristic corresponding to a reflected waveform, such as Rx waveform 618. In other examples, the RF sensing data can also be used to detect motion, determine a location, detect a change in a location or motion pattern, or any combination thereof. In some cases, the distance and angle of arrival of a reflected signal can be used to identify a size, location, movement, and / or orientation of a target (e.g., target 602) in a surrounding environment in order to detect a presence / proximity of the target.

[0149] The processor of receiver 604 can compute the distance and angle of arrival corresponding to a reflected waveform (e.g., the distance and angle of arrival corresponding to Rx waveform 618) by using signal processing, machine learning algorithms, any other suitable technique, or any combination thereof. In other examples, receiver 604 can transmit or communicate the RF sensing data to at least one processor of another computing device, such as a server, which can perform the computation to obtain the distance and angle of arrival corresponding to Rx waveform 618 or other reflected waveform.

[0150] In one or more examples, the angle of arrival of Rx waveform 618 can be computed by the processor of receiver 604 by measuring a time difference of arrival of Rx waveform 618 between individual elements of a receive antenna array of receiver 604. In some examples, the time difference of arrival can be computed by measuring a difference in received phase at each element in the receive antenna array.

[0151] In some cases, the distance and angle of arrival of Rx waveform 618 can be used by the processor of receiver 604 to determine a distance between receiver 604 and target 602 and a location of target 602 relative to receiver 604. The distance and angle of arrival of Rx waveform 618 can also be used to determine a presence, movement, proximity, identity, or any combination thereof of target 602. For example, the processor of receiver 604 can use the computed distance and angle of arrival corresponding to Rx waveform 618 to determine that target 602 is moving towards receiver 604.

[0152] Figure 7 is a diagram illustrating an example of a receiver 704 in the form of a smartphone that utilizes RF bistatic sensing techniques with multiple transmitters (including transmitter 700a, transmitter 700b, and transmitter 700c) that can be used to determine one or more characteristics (e.g., position, velocity or speed, heading, etc.) of a target 702 object. For example, the receiver 704 can use RF bistatic sensing to detect the presence and location of a target 702 (e.g., an object, a user, or a vehicle). The target 702 is depicted in Figure 7 as an object without communication capabilities (which can be referred to as a deviceless object), such as a person, a vehicle (e.g., a vehicle without the capability to transmit and receive messages using a C-V2X or DSRC protocol), or other deviceless object. Figure 6 The bistatic radar system of Figure 7 is similar to the bistatic radar system of Figure 6 , except that, Figure 7 the bistatic radar system of has multiple transmitters 700a, 700b, 700c, whereas

[0153] the bistatic radar system of Figure 7 has only one transmitter 600. Figure 6 The bistatic radar system of Figure 7 includes multiple transmitters 700a, 700b, 700c (e.g., transmitting sensing nodes) that are illustrated in the form of base stations. Figure 4 The bistatic radar system of also includes a receiver 704 (e.g., a receiving sensing node) that is depicted in the form of a smartphone. Each of the transmitters 700a, 700b, 700c is separated from the receiver 704 by a distance that can be compared to an expected distance from the target 702. Similar to the bistatic system of

[0154] , Figure 4 the transmitters 700a, 700b, 700c and the receiver 704 of the bistatic radar system of Figure 5 are positioned apart from each other.

[0155] Transmitters 700a, 700b, 700c can include one or more components for transmitting RF signals. Each of transmitters 700a, 700b, 700c can include at least one processor (e.g., processor 522) capable of determining a signal to be transmitted (e.g., determining a waveform of the signal). Each of transmitters 700a, 700b, 700c can also include an RF transmitter (e.g., RF transmitter 506) for transmitting a Tx signal including Tx waveforms 716a, 716b, 716c, 720a, 720b, 720c. Figure 5 Figure 5 In one or more examples, Tx waveforms 716a, 716b, 716c are RF sensing signals, and Tx waveforms 720a, 720b, 720c are communication signals. In one or more examples, Tx waveforms 720a, 720b, 720c are communication signals that can be used to schedule a transmitter (e.g., transmitters 700a, 700b, 700c) and a receiver (e.g., receiver 704) to perform RF sensing of a target (e.g., target 702) to obtain location information about the target. The RF transmitter can be a transmitter configured to transmit cellular or telecommunication signals (e.g., a transmitter configured to transmit 5G / NR signals, 4G / LTE signals, or other cellular / telecommunication signals, etc.), a Wi-Fi transmitter, a Bluetooth ™ transmitter, any combination thereof, or any other transmitter capable of transmitting RF signals.

[0156] The RF transmitter can be coupled to one or more transmit antennas, such as Tx antennas (e.g., TX antennas 512). In one or more examples, the Tx antennas can be omnidirectional antennas capable of transmitting RF signals in all directions, or directional antennas that transmit RF signals in a particular direction. The Tx antennas can include multiple antennas (e.g., elements) configured as an antenna array. Figure 7

[0157] Figure 5 Receiver 704 can include one or more components for receiving RF signals. For example, receiver 704 can include one or more receive antennas, such as Rx antennas (e.g., Rx antennas 514). In one or more examples, the Rx antennas can be omnidirectional antennas capable of receiving RF signals from multiple directions, or directional antennas configured to receive signals from a particular direction. In some examples, the Rx antennas can include multiple antennas (e.g., elements) configured as an antenna array (e.g., a phased antenna array). Figure 5

[0158] Receiver 704 can also include an RF receiver (e.g., RF receiver 508) coupled to the Rx antennas. In one or more examples, the RF receiver is configured to receive RF signals from the Rx antennas and to provide the received RF signals to the processor (e.g., processor 522). Figure 5 ​​​The RF receiver 510 may include a device for receiving RF waveforms (such as Wi-Fi signals, Bluetooth signals, etc.). ™ One or more hardware components (RF signals, 5G / NR signals, or any other RF signals). The output of the RF receiver can be coupled to at least one processor (e.g., Figure 7 The processor 522). The processor can be configured to process the received waveform (e.g., Rx waveform 718, which is a reflected (echo) RF sensing signal).

[0159] In some examples, transmitters 700a, 700b, and 700c can implement RF sensing techniques (e.g., bistatic sensing techniques) by transmitting Tx waveforms 716a, 716b, and 716c (e.g., radar sensing signals) from a Tx antenna associated with each of transmitters 700a, 700b, and 700c. Although Tx waveforms 716a, 716b, and 716c are illustrated as single lines, in some cases, Tx waveforms 716a, 716b, and 716c can be transmitted in all directions (e.g., via an omnidirectional Tx antenna associated with each of transmitters 700a, 700b, and 700c).

[0160] In one or more aspects, one or more parameters associated with the Tx waveforms 716a, 716b, 716c can be used to increase or decrease the RF sensing resolution. These parameters may include, but are not limited to, frequency, bandwidth, number of spatial streams, number of antennas configured to transmit the Tx waveforms 716a, 716b, 716c, number of antennas configured to receive reflected (echo) RF signals (e.g., Rx waveform 718) corresponding to each of the Tx waveforms 716a, 716b, 716c, number of spatial links (e.g., the number of spatial streams multiplied by the number of antennas configured to receive RF signals), sampling rate, or any combination thereof. The transmitted waveforms (e.g., Tx waveforms 716a, 716b, 716c) and the received waveforms (e.g., Rx waveform 718) may include one or more radar RF sensing signals (also referred to as RF sensing RS). It should be noted that, although Figure 7 Only one reflected sensing signal is shown (e.g., Rx waveform 718), but it should be understood that a separate reflected (echo) sensing signal will be generated by each sensing signal reflected from the target 702 (e.g., Tx waveforms 716a, 716b, 716c).

[0161] exist Figure 8During operation of the system, receiver 704 (e.g., operating as a receiving sensing node) can receive signals corresponding to Tx waveforms 716a, 716b, 716c transmitted by transmitters 700a, 700b, 700c (e.g., each operating as a transmitting sensing node). Receiver 704 can receive signals reflected from objects or people within range of Tx waveforms 716a, 716b, 716c, such as Rx waveform 718 reflected from target 702. In one or more examples, Rx waveform 718 can include multiple sequences corresponding to multiple copies of the sequence included in its corresponding Tx waveform 716a, 716b, 716c. In some examples, receiver 704 can combine the multiple sequences received to improve SNR.

[0162] In some examples, the RF sensing data can be used by at least one processor within receiver 704 to compute distances, angles of arrival (AOAs), TDOAs, angles of departure (AoDs), or other characteristics corresponding to reflected waveforms (e.g., Rx waveform 718). In further examples, the RF sensing data can also be used to detect motion, determine location, detect changes in location or motion patterns, or any combination thereof. In one or more examples, distances and angles of arrival of reflected signals can be used to identify a size, location, movement, and / or orientation of a target (e.g., target 702) in order to detect target presence / proximity.

[0163] The processor of receiver 704 can compute distances and angles of arrival corresponding to reflected waveforms (e.g., distances and angles of arrival corresponding to Rx waveform 718) by using signal processing, machine learning algorithms, any other suitable technique, or any combination thereof. In one or more examples, receiver 704 can transmit or communicate the RF sensing data to at least one processor of another computing device, such as a server, which can perform the computations to obtain distances and angles of arrival corresponding to Rx waveform 718 or other reflected waveforms (not shown).

[0164] In one or more examples, the processor of receiver 704 can compute the angle of arrival (AOA) of Rx waveform 718 by measuring the TDOA of Rx waveform 718 between individual elements of a receive antenna array of receiver 704. In some examples, the TDOA can be computed by measuring a difference in received phase at each element in the receive antenna array. In one illustrative example, to determine the TDOA, the processor can determine a difference in time of arrival of Rx waveform 718 to the receive antenna array elements using one of the receive antenna array elements as a reference. The difference in time is proportional to a difference in distance.

[0165] In some cases, the processor of receiver 704 can use the ranges, AOAs, TDOAs, other measurement information (e.g., AoD, etc.), any combination thereof, of Rx waveforms 718 to determine a range between receiver 704 and target 702, and to determine a location of target 702 relative to receiver 704. In one example, the processor can use the range, AOA, and / or TDOA information as input to apply a multilateration or other location-based algorithm to determine a location (e.g., 3D location) of target 702. In other examples, the processor can use the ranges, AOAs, and / or TDOAs of Rx waveforms 718 to determine a presence, movement (e.g., velocity or speed, heading or direction of movement, etc.), proximity, identity, any combination thereof, or other characteristic of target 702. For example, the processor of receiver 704 can use the ranges, AOAs, and / or TDOAs corresponding to Rx waveforms 718 to determine that the target is moving toward receiver 704.

[0166] Figure 8 is a diagram illustrating geometry for bistatic (or monostatic) sensing. Figure 8 A bistatic radar North reference coordinate system in two dimensions is shown. Specifically, Figure 9 A coordinate system and parameters defining bistatic radar operation in a plane containing transmitter 800, receiver 804, and target 802 (referred to as the bistatic plane) are shown. A bistatic triangle lies in the bistatic plane. Transmitter 800, target 802, and receiver 804 are shown relative to one another. Transmitter 800 and receiver 804 are separated by a baseline distance L. An extended baseline is defined as extending the baseline distance L beyond transmitter 800 or receiver 804. Target 802 and transmitter 800 are separated by a range R T , and target 802 and receiver 804 are separated by a range R R .

[0167] Angle θ T and θ R are the transmitter 800 observation angle and receiver 804 observation angle, respectively, which are considered positive when measured clockwise from North (N). Angle θ T and θ R are also referred to as the angle of arrival (AOA) or line of sight (LOS). The bistatic angle (β) is the angle subtended between transmitter 800, target 802, and receiver 804 in radar. Specifically, the bistatic angle is the angle between transmitter 800 and receiver 804 with the vertex at target 802. The bistatic angle is equal to the transmitter 800 observation angle minus the receiver 804 observation angle θ R (e.g., β = θ T - θ R ).

[0168] When the bistatic angle is exactly zero (0°), the radar is considered a monostatic radar; when the bistatic angle is close to zero, the radar is considered a pseudo-monostatic; and when the bistatic angle is close to 180 degrees, the radar is considered a forward scatter radar. Otherwise, the radar is considered and referred to as a bistatic radar only. The bistatic angle (β) can be used to determine the radar cross section of a target.

[0169] Figure 10 is an illustration of an example of a bistatic range 910 that exemplifies bistatic sensing. In this figure, a transmitter (Tx) 900 of a radar, a target 902, and a receiver (Rx) 904 are shown relative to each other. The transmitter 900 is separated from the receiver 904 by a baseline distance L, the target 902 is separated from the transmitter 900 by a distance Rtx, and the target 902 is separated from the receiver 904 by a distance Rrx.

[0170] Bistatic range 910 (shown as an ellipse) refers to the measured distance made by a radar with a separated transmitter 900 and receiver 904 (e.g., the transmitter 900 and receiver 904 are positioned away from each other). The receiver 904 measures the time of arrival from when the transmitter 900 transmits a signal to when the receiver 904 receives the signal from the transmitter 900 via the target 902. The bistatic range 910 defines an ellipse of constant bistatic range, called an equidistance contour, on which the target 902 lies with foci centered at the transmitter 900 and receiver 904. If the target 902 is at a distance Rrx from the receiver 904, at a distance Rtx from the transmitter 900, and the receiver 904 and transmitter 900 are separated by a distance L, then the bistatic range is equal to Rrx + Rtx - L. It should be noted that the motion of the target 902 causes a rate of change of the bistatic range, which results in a bistatic Doppler shift.

[0171] In general, the constant bistatic range points trace an ellipsoid with the transmitter 900 and receiver 904 locations as foci. The bistatic equidistance contour is the location where the ground cuts the ellipsoid. When the ground is flat, this intersection forms an ellipse (e.g., the bistatic range 910). Note that these ellipses are not centered on mirror points unless the two platforms have equal height.

[0172] Figure 3 An example 1000 of wireless communications between devices based on sidelink communications is exemplified. The communications can be based on a slot structure (e.g., as described in FIG. 3), for example. Figure 11The illustrated time slot structure). For example, a transmitting UE 1002 can transmit a transmission 1014 that is receivable by receiving UEs 1004, 1006, 1008, which includes, for example, a control channel and / or a corresponding data channel. At least one of the UEs can be in the form of an autonomous vehicle or unmanned aerial vehicle. The control channel can include information used to decode the data channel and can also be used by receiving devices to avoid interference by refraining from transmitting during the data transmission on the occupied resources. The number of RBs and the transmission time interval (TTI) that the data transmission will occupy can be indicated in a control message from the transmitting device. In addition to operating as a receiving device, UEs 1002, 1004, 1006, 1008 can each also be capable of operating as a transmitting device. Thus, UEs 1006, 1008 are illustrated as transmitting transmissions 1016, 1020. Transmissions 1014, 1016, 1020 (and 1018 by network device 1007, such as a road-side unit) can be broadcast or multicast to devices within range. For example, UE 1014 can transmit a communication intended to be received by other UEs within a range 1001 of UE 1014. Additionally / alternatively, network device 1007 can receive and / or transmit communications 1018 to UEs 1002, 1004, 1006, 1008. UEs 1002, 1004, 1006, 1008, or network device 1007 can include a detection component. UEs 1002, 1004, 1006, 1008, or network device 1007 can also include a vehicle-based safety message or mitigation component.

[0173] Figure 11 Examples of comb structures for reference signals (e.g., PRS, SRS, etc.) are shown in FIG. 11. For example, comb structure 1110 is a comb-2 structure with two symbols (denoted as a comb-2 / 2-symbol structure). According to the comb-2 / 2-symbol structure of comb structure 1110, each alternating symbol is assigned to a reference signal resource. Figure 12 The comb pattern in FIG. 11 is for one transmission-reception point (TRP). An overview of comb structures 1110, 1112, 1114, 1116, 1118, 1120, 1122, and 1124 is provided in Table 2 below:

[0174]

[0175] Table 2

[0176] As previously noted, systems and techniques are described herein that apply solutions associated with enhancements to DDM MIMO sensing based on Doppler spectrum puncturing. Figure 12This is a diagram illustrating an example of a system 1200 used to apply an enhancement solution (e.g., method or rule) for DDM MIMO sensing based on Doppler spectral perforation. Figure 12 In this embodiment, system 1200 is shown as including a network device 1210 in the form of a UE. Network device 1210 (e.g., UE) can operate as a radar Rx for sensing purposes. A network device 1220 in the form of a base station (e.g., a gNB or a portion thereof, such as a CU, DU, RU, near-RT RIC, non-RT RIC, etc.) is also shown. Network device 1220 (e.g., gNB) can operate as a radar Tx for sensing purposes. System 1200 also includes multiple network entities 1240, 1250, wherein network entity 1240 is in the form of a radar server and network entity 1250 is in the form of a location server.

[0177] System 1200 may include, for example Figure 12 The system 1200 may include more or fewer network devices and / or more or fewer network entities as shown. Additionally, the system 1200 may include devices such as... Figure 12 This includes different types of network devices (e.g., vehicles) and / or different types of network entities (e.g., network servers). Furthermore, the UE can be used as a radar Tx instead of... Figure 20 The base station shown is (e.g., gNB). Furthermore, in one or more examples, network device 1210 (e.g., UE) may be equipped with heterogeneous capabilities, which may include, but are not limited to, 4G / 5G cellular connectivity, GPS capabilities, camera capabilities, radar capabilities, and / or LiDAR capabilities. Network devices 1210, 1220 and network entities 1240, 1250 may be able to perform wireless communication with each other via communication signals (e.g., signals 1270a, 1270b, 1270c, 1270d).

[0178] In one or more examples, network devices 1210, 1220 may be able to send and receive some type of sensing signal (e.g., camera, RF sensing signal, optical sensing signal, etc.). In some cases, network devices 1210, 1220 may send and receive sensing signals (e.g., RF sensing signals 1260a, 1260b) for use in detecting nearby targets (e.g., target 1230 in the form of a vehicle) using one or more sensors. In some cases, network devices 1210, 1220 may detect nearby targets based on one or more images or frames captured using one or more cameras.

[0179] The network devices 1220 that can operate as radars can perform RF sensing (e.g., bi- static sensing or monostatic sensing) of at least one target (e.g., target 1230) to obtain RF sensing measurements (e.g., Doppler measurements, RTT measurements, TOA measurements, and / or TDOA measurements) of the target (e.g., target 1230). The RF sensing measurements of the target (e.g., target 1230) can be used (e.g., by at least one processor of at least one of the network devices 1210, 1220 and / or at least one of the network entities 1240, 1250) to determine one or more characteristics (e.g., velocity, location, distance, movement, heading, size, and / or other characteristics) of the target (e.g., target 1230).

[0180] As previously mentioned, generally, sensing involves monitoring moving targets (e.g., target 1230) with different motions (e.g., moving cars or pedestrians, body motions of a person such as breathing, and / or other micro-motions related to the target). The Doppler, which measures the phase change in the signal and indicates motion, is an important characteristic for sensing of the target (e.g., target 1230). Thus, to obtain an accurate estimate of the motion of the target, the phase of the signal should be continuous (e.g., the signal should maintain phase continuity).

[0181] During operation of the system 1200, the network device 1220 (e.g., a base station) operating as a radar Tx can transmit an RF sensing signal 1260a toward a target (e.g., target 1230), for example, when performing bi-static sensing of the target (e.g., target 1230). The RF sensing signal 1260a can be included within a communication signal and a sensing signal that are multiplexed together (e.g., via time division multiplexing and / or frequency division multiplexing) for joint communication and sensing purposes. The sensing signal 1260a can reflect off the target (e.g., target 1230) to produce an RF reflected sensing signal 1260b, which can reflect toward the network device 1210 (e.g., a UE). The network device 1210 (e.g., a UE) operating as a radar Rx can receive the reflected sensing signal 1260b. After the network device (e.g., a UE) receives the reflected sensing signal 1260b, the network device (e.g., a UE) can obtain measurements (e.g., Doppler measurements, RTT measurements, TOA measurements, and / or TDOA measurements) of the reflected sensing signal 1260b. At least one processor of at least one of the network devices 1210, 1220 and / or at least one of the network entities 1240, 1250 (e.g., using the measurements) can determine one or more characteristics (e.g., velocity, location, distance, movement, heading, size, and / or other characteristics) of the target (e.g., target 1230). Figure 13The processor 2010 of the network device 1210 (e.g., UE) can then determine or compute characteristics (e.g., velocity, position, distance, movement, heading, size, etc.) of the target (e.g., target 1230) by using the sensing measurements (e.g., Doppler measurements, TOA measurements, and / or TDOA measurements) from the received reflected sensing signals 1260b.

[0182] In some examples, the network device 1210 (e.g., UE) can transmit measurements (e.g., Doppler measurements, RTT measurements, TOA measurements, and / or TDOA measurements) and / or determined characteristics (e.g., velocity, position, distance, movement, heading, size, etc.) of the target (e.g., target 1230) to the network device 1220 (e.g., base station) and / or the network entity 1240 (e.g., radar server) via the communication signals 1270a, 1270b. The network device 1220 (e.g., base station) and / or the network entity 1240 (e.g., radar server) can then transmit the measurements (e.g., Doppler measurements, RTT measurements, TOA measurements, and / or TDOA measurements) and / or determined characteristics (e.g., velocity, position, distance, movement, heading, size, etc.) of the target (e.g., target 1230) to the network entity 1240 (e.g., radar server) and / or the network entity 1250 (e.g., location server such as a location management function (LMF)) via the communication signals 1270c, 1270d.

[0183] As previously mentioned, MIMO is a multiple-antenna spectrum-efficient technology. MIMO has become a major driving force for next-generation antenna technology for cellular networks. MIMO systems can transmit more than one signal on the same channel, which can provide increased spectral efficiency and total throughput. By exploiting spatial separation, the antennas of a MIMO system are spaced apart at specific distances and angles for various purposes, such as to reduce correlation between different sub-channels, to implement precoding / beamforming purposes, etc., thereby compensating for self-interference. MIMO systems can provide a robust wireless communication mechanism to address fading and shadowing caused by multiple transmission paths and long distances. Within a MIMO system, various data streams can be transmitted simultaneously, which can provide multiplexing gain and improved total throughput. For at least these reasons, MIMO has recently been implemented in cellular wireless communication technology and is included in various wireless projects and standards, such as including 5G NR.

[0184] One simple form of MIMO is point-to-point MIMO, in which two systems (e.g., a base station and a UE) each employ multiple antennas to communicate with each other. Using multiple antennas can provide increased air interface capacity. However, point-to-point MIMO employs a multiple antenna configuration that requires additional hardware at both the base station and the end user device (e.g., in the UE). Requiring additional hardware at both the base station and the user device is disadvantageous for point-to-point MIMO because it results in increased overall system complexity. As previously noted, in some cases, end user equipment (e.g., a UE) of a mobile communication system can not be able to support multiple antennas, such as due to its small physical size and / or low cost requirements of the UE device.

[0185] As previously noted, point-to-point MIMO is characterized as single-user MIMO (SU-MIMO). SU-MIMO provides increased data rates by transmitting multiple data streams to a particular user device (e.g., a particular UE). Similar to point-to-point MIMO, SU-MIMO has the disadvantage of requiring user devices (e.g., UEs) to support multiple antennas.

[0186] In contrast to point-to-point MIMO and SU-MIMO, multi-user MIMO (MU-MIMO) does not have the disadvantage of requiring user devices to support multiple antennas. For MU-MIMO, multiple users share the same time and frequency resources, while each base station (e.g., gNB or eNB) or a portion thereof (such as a CU, DU, RU, near-RT RIC, or non-RT RIC) is equipped with multiple antennas (e.g., an antenna array) and simultaneously serves many users (e.g., UEs). Each end user device (e.g., UE) can employ a single antenna or multiple antennas, where when a single antenna is used, complex hardware can only be required at the base station side. For a MU-MIMO system, the cost and complexity of the antenna system is significantly reduced because low-cost single antennas (e.g., dipole antennas) can be used for end user devices (e.g., UEs), and more expensive, complex hardware can be utilized only at the base station side.

[0187] Due to the diversity in distance, angle, and quality of signals of multiple users in a MU-MIMO system, the performance of a MU-MIMO system is generally less affected by the transmission environment compared to point-to-point MIMO. This advantage is achieved by a MU-MIMO system that utilizes selective beamforming and power control to eliminate interference. MU-MIMO systems provide high reliability and throughput, and thus, have become an integral part of wireless communication systems, including Wi-Fi, LTE, and 5G networks.

[0188] Massive MIMO (mMIMO) is a form of MU-MIMO that employs a larger number of antennas at the base station than MU-MIMO and, as a result, the number of users (e.g., UEs) that can be served can be significantly increased over a MU-MIMO system. For example, in mMIMO, a single base station with many antennas can serve a large number of users. With a large number of antennas in each base station, the channel vector between a user (e.g., UE) and a base station is almost rectangular for each pair, which can provide exceptionally linear transmission. In mMIMO, large throughput can be achieved due to multiplexing gain, diversity gain, and array gain. In mMIMO, the large number of antennas at the base station can serve hundreds of users with the same frequency resources by exploiting antenna beamforming techniques.

[0189] In mMIMO, the more antennas that are employed at each base station, the more robust the communication operations are. In theory, mMIMO can employ an infinite number of antennas at each of the base stations. However, typically (e.g., in 5G networks), 64 to 128 antennas (e.g., 64 receive antennas and 64 transmit antennas) have been practically utilized in mMIMO base stations. An advantage of mMIMO is that sophisticated hardware can be required only at the base station and not at the user equipment (e.g., UEs), which can each use a single antenna and simple antenna design. Another advantage of mMIMO is that it has a scalable architecture that can be easily scaled up to serve more users by upgrading the antenna system on the base station only.

[0190] Currently, some radars (e.g., such as automotive radars) transmit signals with a frequency-modulated continuous wave (FMCW) waveform. A FMCW waveform (e.g., also referred to as a chirp or a pulse) is a complex sinusoid with a frequency that increases linearly over time (e.g., ramps up). A FMCW radar transmits a chirp (e.g., a chirp 1310a, 1310b, 1310c of FIG. 13) in a periodic manner, where the period is referred to as the pulse repetition interval (PRI). Figure 13

[0191] Figure 13 is a diagram 1300 illustrating an example of a chirp (or pulse) 1320 transmitted by multiple antennas (e.g., transmit antennas of a FMCW radar (which can be a MIMO radar) of a network device such as a UE or a base station, e.g., a gNB). In Figure 14A , the multiple antennas are shown transmitting a chirp, where each antenna sequentially transmits a chirp within a pulse repetition interval , for example. The first antenna transmits a chirp within a pulse repetition interval ​N number of chirps 1310a, 1310b, 1310c are transmitted. Multiple antennas can transmit at the same time and frequency resource. The antennas can transmit a respective sensing waveform at the same time, which can be formulated by multiplying a common FMCW waveform with a phase code that is different for each antenna and changes between pulses. As will be discussed in detail later, the common FMCW waveform can be multiplied with a phase code denoted as where M is the index of the antenna, N is the number of antennas, and n is the index of the chirp (or pulse). The antennas can transmit concurrently at the same time and frequency resource, but each antenna can use a different phase code. The phase code can be referred to as a “slow-time phase code” because the phase code is applied across chirps (or pulses) rather than across samples within the same chirp (or pulse). The phase coding can be performed chirp-by-chirp rather than sample-by-sample.

[0192] Target echoes received at a radar receiver can include delayed and attenuated copies of the transmitted chirps. The received signal can mix with the transmitted chirps, which can produce a complex sinusoid that can be referred to as a beat signal.

[0193] The process of obtaining the beat signal can be implemented in the RF domain by using a mixer followed by a BPF to remove signals with frequencies outside the band of interest, which can also impose a limit on the maximum detectable range. After sampling the beat signal, estimation of the beat frequency can be implemented in the digital domain. In many scenarios, such as in automotive scenarios, the beat frequency can be much smaller than the signal bandwidth, and thus, a low-speed ADC (e.g., which is low cost) can be used to sample the beat signal. FMCW waveforms are often used in the radar industry due to their low performance cost ratio, which is at least partially achieved by using low-cost ADCs. The time during one cycle or chirp is often referred to as “fast time,” while the time across multiple cycles or chirps is often referred to as “slow time.” For example, if the beat signal is sampled and the samples for each chirp are placed within the columns of a matrix, the row index of the matrix can correspond to fast time, and the column index of the matrix can correspond to slow time. By applying an FFT to the sampled beat signal along fast time, the range frequency can be determined. A second FFT can be applied along slow time to determine the Doppler frequency (e.g., Doppler frequency 1400). Figure 14B Figure 14A

[0194] Figure 14A ​​This is a diagram illustrating an example of a Doppler frequency of 1400 Hz transmitted from two antennas (e.g., antenna Tx1 and antenna Tx2). Specifically, in Figure 14A In the diagram, the x-axis represents the Doppler frequency of 1400 Hz. For example... Figure 14B The Doppler frequency 1400 shown is illustrated as having both negative and positive components. Specifically, the Doppler frequency 1400 is illustrated as having three sub-bands 1410, 1420a, and 1420b, where sub-band 1410 corresponds to antenna Tx1, and sub-bands 1420a and 1420b correspond to antenna Tx2.

[0195] Figure 14A This is an example of having Figure 14B Example spectrum 1402 of the range-velocity distribution of a DDM MIMO radar with two transmitting antennas. Specifically, for Figure 15A In spectrum 1402, the x-axis represents distance in meters (m), the y-axis represents velocity (or Doppler) in meters per second (m / s), and the z-axis represents amplitude in decibels (dB). For this example, the distance and Doppler spectrum is the distance and Doppler spectrum of a target at a distance of 75 m and a velocity (or Doppler) of 10 m / s.

[0196] In spectrum 1402, two peaks, 1430a and 1430b, are shown. The number of peaks in the spectrum corresponds to the number of transmitting antennas. The real target is only within one of these peaks, and therefore, peak blurring may occur. The other peak is simply a repetition, which may be due to aliasing. In this example, the real target is located in the first peak, which is peak 1430a.

[0197] In some scenarios, MIMO radar can be used to transmit FMCW sequences. The transmitting antennas of the MIMO radar can transmit FMCW sequences in a manner that guarantees their orthogonality. At each receiving antenna (e.g., in the MIMO radar), the contribution of each transmitting antenna can be extracted by utilizing waveform orthogonality. Various techniques can be used to achieve waveform orthogonality while transmitting FMCW, including but not limited to slow-time Doppler division multiplexing (SL-DDM).

[0198] In order to achieve waveform orthogonality while transmitting FMCW using SL-DDM, pulse repetition intervals should be used. A total of N chirps (i.e., pulses) are transmitted sequentially. All transmit antennas should simultaneously transmit the same FMCW waveform after multiplying it by a phase code, which is different for each antenna and changes between pulses. The transmitted waveform is as follows: Where M = 1, 2, ... And n = 0, 1, 2, ..., N-1. To separate the h-th transmitted signal at the l-th receiver, after performing a range FFT, slow-time Doppler demodulation can be applied to all range intervals corresponding to the same chirp. The Doppler demodulation outputs of N chirs can be assembled into a vector. Then you can work on vectors. Apply Doppler FFT.

[0199] In one or more examples, in order to separate the transmitted signal in the Doppler domain, phase codes can be used to separate the interfering Doppler FFT. Shift to a frequency higher than the maximum detectable Doppler frequency The frequency of the phase code. A low-pass filter (LPF) can then be applied to remove interference. An example of a phase code is... Where M = 1, 2, ... And n = 0, 1, 2, ..., N-1, and where the initial phase The transmission is linear across different transmitting antennas, making Using this method, the radar pulse repetition frequency Should be greater than Therefore, if If it remains unchanged, the maximum detectable unambiguous Doppler frequency decreases to As the number of antennas increases (e.g., (Increase), may need to be reduced , making Greater than This can reduce Doppler blur.

[0200] The methods used to reduce Doppler blur vary at different observation times. Doppler unwrapping or dealiasing algorithms can be very useful. In one or more aspects, the system and techniques provide solutions for enhancing DDM MIMO sensing based on Doppler spectral punching. The system and techniques also provide solutions to mitigate Doppler blurring that may be caused by aliasing.

[0201] In one or more aspects, Doppler spectral punching can be employed to mitigate Doppler ambiguity. In one or more examples, a special Doppler spectrum with some empty subbands can be achieved within the MIMO radar waveform via slow-time (SL) phase decoding. In some examples, the empty subbands in the Doppler spectrum can be coherent.

[0202] An example code that can be used for a special Doppler spectrum with some coherent empty subbands could be Where m = 1, 2, ... And among them This is the total number of Tx antennas, and is the number of consecutive null subbands in the Doppler spectrum.

[0203] Figure 15B 、 Figure 15C and Figure 15A Examples are illustrated of implementing a special Doppler spectrum with consecutive null subbands within a MIMO radar waveform by SL phase coding. Specifically, Figure 15A is a diagram 1500 illustrating an example of chirps (or pulses) 1520 transmitted by four Tx antennas (e.g., transmit antennas of an FMCW radar, which can be a MIMO radar of a network device such as a UE or a base station, e.g., a gNB). In Figure 15B , the four antennas are shown transmitting chirps, where each of the four antennas sequentially transmits a chirp within a pulse repetition interval . For example, a first antenna transmits N number of chirps 1510a, 1510b, 1510c within a pulse repetition interval (e.g., corresponding to a subband Tx1 1530 of Figure 15B ). The four antennas can transmit at the same time and frequency resources and can transmit the same FMCW waveform concurrently. The FMCW waveform can be multiplied by a phase code , where M is the index of the antenna, is the number of antennas, and n is the index of the chirp (or pulse). The four antennas can transmit concurrently at the same time and frequency resources, but each of the four antennas can use a different phase code. The phase code can be referred to as a “slow-time phase code” because the phase code is applied across chirps (or pulses) rather than across samples within the same chirp (or pulse). The phase coding can be performed per chirp (e.g., rather than per sample).

[0204] Figure 15B is a diagram illustrating an example of Doppler frequencies 1502 from transmissions by four antennas (e.g., antenna Tx1, antenna Tx2, antenna Tx3, and antenna Tx4), where null subbands 1570a, 1570b are consecutive. Specifically, in Figure 15B , the x-axis represents Doppler frequencies 1502. As Figure 15CThe illustrated Doppler frequency 1502 is shown as having only positive components (e.g., note that negative components are not shown in the figure). Specifically, the Doppler frequency 1502 is shown as having six subbands (e.g., subbands 1530, 1540, 1550, 1560, 1570a, 1570b). The subband 1530 corresponds to antenna Tx1, the subband 1540 corresponds to antenna Tx2, the subband 1550 corresponds to antenna Tx3, and the subband 1560 corresponds to antenna Tx4. The subbands 1570a and 1570b are empty. The subbands 1530, 1540, 1550, 1560 are each shown as including a respective peak (e.g., peaks 1535, 1545, 1555, 1565). One of these peaks corresponds to the real target, while the remaining peaks are merely repetitions, which can be due to aliasing. Thus, the peaks are ambiguous.

[0205] Figure 15B Table 1504 is an example illustrating example Doppler spectrum patterns 1590, where empty subbands are contiguous. The Doppler spectrum patterns 1590 can be used to determine which of the multiple ambiguous peaks (e.g., peaks 1535, 1545, 1555, 1565) of Figure 15B is designed such that the peak corresponding to antenna Tx1 is the real peak in the set of peaks.

[0206] In the table 1504, six different Doppler spectrum patterns 1590 are shown. Each Doppler spectrum pattern 1590 has an associated Doppler spectrum hypothesis index 1580 (e.g., 1, 2, 3, 4, 5, and 6). To determine which of the multiple ambiguous peaks is the real peak corresponding to the target, the resulting Doppler frequency should match one of the Doppler spectrum patterns 1590.

[0207] For example, Figure 16A The Doppler frequency 1502 of the transmission from the four antennas (e.g., antenna Tx1, antenna Tx2, antenna Tx3, and antenna Tx4) matches the Doppler spectrum pattern 1590 with Doppler spectrum hypothesis index 1580 of 1. As mentioned, the code is designed such that the peak corresponding to antenna Tx1 is the real peak in the set of peaks. Thus, the real peak is the peak 1535 contained within the first subband 1530, which corresponds to antenna Tx1.

[0208] As previously mentioned, Doppler spectrum puncturing can be employed to mitigate Doppler ambiguity, where a special Doppler spectrum with some empty subbands can be implemented within a MIMO radar waveform through SL phase coding. In one or more examples, the empty subbands in the Doppler spectrum can be non-contiguous.

[0209] ​One example code that can be used for a special Doppler spectrum with some non-consecutive empty subbands can be where m is a virtual antenna index, m = 1, 2, …, + and is the total number of physical transmit (Tx) antennas, and is the number of non-consecutive empty subbands in the Doppler spectrum. In one or more examples, when a subband is punctured, and when a subband is not punctured, .

[0210] Figure 16B , Figure 16C and Figure 16A illustrate examples of implementing a special Doppler spectrum with non-consecutive empty subbands within a MIMO radar waveform through SL phase coding. Specifically, Figure 16A is a diagram 1600 illustrating an example of a chirp (or pulse) 1620 transmitted by four Tx antennas (e.g., transmit antennas of a FMCW radar, which can be a MIMO radar of a network device such as a UE or a base station, e.g., a gNB). Figure 16B The four antennas in are shown to transmit a chirp, where each of the four antennas sequentially transmits a chirp within a pulse repetition interval (e.g., which corresponds to a subband Tx1 1630 of Figure 16B ). For example, a first antenna transmits N number of chirps 1610a, 1610b, 1610c within a pulse repetition interval , where M is an index of an antenna, is a number of antennas, and n is an index of a chirp (or pulse). The four antennas can transmit concurrently at the same time and frequency resources, but each of the four antennas can use a different phase code. The phase code can be referred to as a “slow-time phase code” because the phase code is applied across the time domain, rather than the frequency domain. The phase coding can be performed per chirp (e.g., rather than per sample).

[0211] Figure 16B is a diagram illustrating an example of Doppler frequencies 1602 from transmissions of four antennas (e.g., antenna Tx1, antenna Tx2, antenna Tx3, and antenna Tx4), where empty subbands 1670a, 1670b are non-consecutive. Specifically, in Figure 16B the x-axis represents Doppler frequencies 1602. As Figure 16CThe illustrated Doppler frequency 1602 is shown as having only positive components (e.g., note that negative components are not shown in the figure). Specifically, the Doppler frequency 1602 is shown as having six subbands (e.g., subbands 1630, 1640, 1650, 1660, 1670a, 1670b). Subband 1630 corresponds to antenna Tx1, subband 1640 corresponds to antenna Tx2, subband 1650 corresponds to antenna Tx3, and subband 1660 corresponds to antenna Tx4. Subbands 1670a and 1670b are empty. Subbands 1630, 1640, 1650, 1660 each include a respective peak (e.g., peaks 1635, 1645, 1655, 1665). One of these peaks corresponds to the real target, while the remaining peaks are merely repetitions (e.g., this can be due to aliasing). Thus, the peaks are ambiguous.

[0212] Figure 16B Table 1604 is an example illustrating example Doppler spectrum patterns 1690, where empty subbands are non-consecutive. The Doppler spectrum patterns 1690 can be used to determine which of the multiple ambiguous peaks (e.g., peaks 1635, 1645, 1655, 1665) of Figure 16B are designed such that the peak corresponding to antenna Tx1 is the real peak in the set of peaks.

[0213] In table 1604, six different Doppler spectrum patterns 1690 are shown. Each Doppler spectrum pattern 1690 has a Doppler spectrum hypothesis index 1680 (e.g., 1, 2, 3, 4, 5, and 6). To determine which of the multiple ambiguous peaks is the real peak corresponding to the target, the resulting Doppler frequency should match one of the Doppler spectrum patterns 1690.

[0214] For example, Figures 15A to 16C The Doppler frequency 1602 of the transmission from the four antennas (e.g., antenna Tx1, antenna Tx2, antenna Tx3, and antenna Tx4) matches the Doppler spectrum pattern 1690 with Doppler spectrum hypothesis index 1680 of 1. As mentioned, the code is designed such that the peak corresponding to antenna Tx1 is the real peak in the set of peaks. Thus, the real peak is peak 1635, which is contained within the first subband 1630, which corresponds to antenna Tx1.

[0215] In one or more aspects, Doppler spectrum puncturing can be employed for multi-user multiplexing. In some scenarios, multiple users can be performing sensing. Doppler spectrum puncturing can be used to multiplex these users (or nodes) using the same time and frequency resources. In one or more examples, the nodes (or users) can each be a network device, such as a UE or a base station (e.g., gNB). ​

[0216] In one or more examples, when multiple sensing nodes (or sensor users) share the same time and frequency resources for MIMO sensing, the Doppler spectrum puncturing method (e.g., as discussed in the description of Figure 17 ) can be used for multi-sensing user multiplexing to reduce interference. In one or more examples, a group of sensing nodes (or users) can be assigned to the same SL phase code . Thus, each user can be mapped to an antenna index used in the Doppler spectrum puncturing method. Previously, each antenna was mapped to an antenna index. For these examples, each node (or user) can be mapped to an antenna index for multiplexing purposes.

[0217] Each sensing node (or user) can also be assigned a specific Doppler spectrum puncturing vector , where each element of the vector is either 0 or 1.0 to indicate whether the corresponding subband spectrum is punctured or not (e.g., 0 can indicate that the subband is punctured, and 1.0 can indicate that the subband is not punctured). The indication of 0 or 1.0 can be used to determine whether to apply the phase code. For example, if the corresponding subband spectrum is indicated to not be punctured, then the phase code can be applied to that particular chirp or OFDM symbol. However, if the corresponding subband spectrum is indicated to be punctured, then the phase code need not be applied.

[0218] In one or more examples, the same sensing waveform can be configured for the sensing nodes within a group, but each sensing node should apply its node-specific SL phase code. In some examples, the multiplexing based on Doppler spectrum puncturing can be combined with other multiplexing to increase system capacity. For example, different groups of nodes can use different sensing waveform parameters. Different sensing waveform parameters can include, but are not limited to, different starting points of the chirp signal, different frequency bands, and different slopes of the chirp signal. However, within the same group of nodes, SL-DDM can be used for further multiplexing.

[0219] In one or more examples, a sensing node can report its capability regarding SL-DDM MIMO sensing to the network (e.g., a network entity, such as a network server, e.g., a radar server or a location server). In some examples, the sensing node’s capability regarding SL-DDM MIMO can be the maximum number of antennas for SL-DDM MIMO sensing.

[0220] Figure 17 is a diagram illustrating an example of transmitted Doppler frequencies 1700, 1702, 1704, 1706 for MIMO sensing with four different users. Specifically, in Figure 17 , the x-axis represents Doppler frequency. As Figure 18The illustrated transmitted Doppler frequencies 1700, 1702, 1704, 1706 are shown as having only positive components (e.g., note that negative components are not shown in the figure). Each Doppler frequency 1700, 1702, 1704, 1706 corresponds to a node (or a user). For example, Doppler frequency 1700 corresponds to node 1 (or user 1), Doppler frequency 1702 corresponds to node 2 (or user 2), Doppler frequency 1704 corresponds to node 3 (or user 3), and Doppler frequency 1706 corresponds to node 4 (or user 4). Multiplexing is such that in the Doppler domain, non-empty subbands do not interfere with each other (e.g., collide).

[0221] Each Doppler frequency 1700, 1702, 1704, 1706 is shown as having eight subbands. Doppler frequency 1700 includes subband 1710 (e.g., which corresponds to antenna Tx1), subband 1720 (e.g., which corresponds to antenna Tx2), and subbands 1730a, 1730b, 1730c, 1730d, 1730e, 1730f (e.g., which are empty). Doppler frequency 1702 includes subband 1712 (e.g., which corresponds to antenna Tx1), subband 1722 (e.g., which corresponds to antenna Tx2), and subbands 1732a, 1732b, 1732c, 1732d, 1732e, 1732f (e.g., which are empty). Doppler frequency 1704 includes subband 1714 (e.g., which corresponds to antenna Tx1), subband 1724 (e.g., which corresponds to antenna Tx2), and subbands 1734a, 1734b, 1734c, 1734d, 1734e, 1734f (e.g., which are empty). Doppler frequency 1706 includes subband 1716 (e.g., which corresponds to antenna Tx1), subband 1726 (e.g., which corresponds to antenna Tx2), and subbands 1736a, 1736b, 1736c, 1736d, 1736e, 1736f (e.g., which are empty).

[0222] In one or more aspects, a joint design of SL-DDM and multi-pulse repetition frequency (PRF) can be employed. In one or more examples, a multi-PRF (or equivalently, a multi-sensing reference signal (RS) periodicity) can be configured jointly with SL-DDM to mitigate Doppler ambiguity. Multi-PRF can be used for Doppler ambiguity mitigation. For example, when a signal with multi-PRF is received and the repetition pattern is broken, ambiguity can be mitigated (e.g., removed).

[0223] Figure 18 An example of multi-PRF for mitigating Doppler ambiguity is shown. Specifically, Figure 18is a plot illustrating an example of Doppler frequency 1800 from transmissions of four antennas, where the periodicity of one subband 1820 corresponding to an antenna (e.g., antenna Tx2) is doubled. The Doppler frequency 1800 is shown to include five subbands, including subband 1810 (e.g., which corresponds to antenna Tx1), subband 1820 (e.g., which corresponds to antenna Tx2), subband 1830 (e.g., which corresponds to antenna Tx3), subband 1850 (e.g., which is empty), and subband 1840 (e.g., which corresponds to antenna Tx4).

[0224] For example, as shown in FIG. 18A, the sensing reference signal periodicity of antenna Tx2 is twice that of antennas Tx1, Tx3, and Tx4. The Doppler frequency 1800 of subband 1820 corresponding to antenna Tx2 is doubled because the periodicity of the sensing reference signal of Tx2 is doubled. This doubling of subband 1820 can be achieved by puncturing (e.g., time-domain puncturing or time-domain downsampling) the sensing reference signal (RS) of Tx2. In one or more examples, puncturing, muting, or downsampling a signal can increase the periodicity of the signal. Time-domain puncturing based on multiple PRFs can be combined with Doppler spectrum puncturing, as shown in the following examples. Figure 18

[0225] In the example of FIG. 18A, the peak of subband 1820 is not aligned with the peaks of subbands 1810, 1830, and 1840. Subbands 1810, 1830, and 1840 have the same periodicity, which means that their peaks repeat in some spatial pattern, and thus, their transmitted signals will have the same gap between their repetitions (e.g., between chirps). Because the repetition (e.g., between chirps) is broken in the transmission for antenna Tx2, the aliasing can be mitigated (e.g., removed). Figure 19

[0226] In one or more aspects, in cellular-based RF sensing, for DDM-MIMO sensing, each sensing node can be configured with a base waveform (e.g., a radar waveform, such as an FMCW waveform or an OFDM-based waveform) and a SL phase code (e.g., which can be applied to multiple radar pulses or OFDM symbols).

[0227] In one or more aspects, DDM can also be applied to multiplexing for communication. In one or more examples, multiplexing of SRS ports can enable longer duration of SRS transmission with enhanced coverage. In some examples, enhancements to DDM as previously described can also be applied to multiplexing for communication.

[0228] Figure 20 ​​is a flow chart illustrating an example of a process 1900 for wireless communications utilizing an enhanced method for DDM MIMO sensing based on Doppler spectrum puncturing. The process 1900 can be performed by a network device such as a UE, a base station (e.g., gNB), a portion of a base station (e.g., one or more of a CU, a DU, a RU, and / or other portions of a base station having a disaggregated architecture), or a component or system (e.g., a chipset) of a UE or base station. The UE can be a mobile device (e.g., a mobile phone), a vehicle, a wearable device (e.g., a watch or other wearable device that connects to a network), an extended reality (XR) device (e.g., a virtual reality (VR) or augmented reality (AR) headset or glasses), or other types of UEs. The operations of process 1900 can be implemented as software components that are run on a processor 2010 of a wireless communication device, or other processor (e.g., a Figure 15A processor of a server-based device, a system-on-chip (SoC), an application-specific integrated circuit (ASIC), a microprocessor, or other processing device). Additionally, the transmission and reception of signals by the wireless communication device in process 1900 can be enabled, for example, by one or more antennas and / or one or more transceivers (e.g., wireless transceivers).

[0229] At block 1910, the network device (or a component thereof) can transmit a sensing signal for sensing one or more targets. The transmitted sensing signal and at least one sensing signal transmitted by at least one other network device of the plurality of network devices include one or more phase codes and a same frequency modulated carrier wave (FMCW). Each phase code of each sensing signal corresponds to one or more Doppler spectrum patterns (e.g., Doppler spectrum patterns 1690 of FIG. 16). In some aspects, the transmitted sensing signal and the at least one sensing signal are transmitted at a same time and using a same one or more frequency resources. In some cases, the phase code of the transmitted sensing signal is different than at least one phase code of the at least one other network device. In some cases, the phase code of the transmitted sensing signal is the same as at least one phase code of the at least one other network device. In some examples, the one or more Doppler spectrum patterns can include contiguous null subbands, such as shown in Figure 15B 、 Figure 15C and Figure 16A In some examples, the one or more Doppler spectrum patterns can include non-contiguous null subbands, such as shown in Figure 16B 、 Figure 16C and Figure 16B

[0230] One illustrative example of a phase code is where M is an index of an antenna (e.g., M = 1, 2, …, ), is a number of antennas, and n is an index of a chirp (or pulse) (e.g., n = 0, 1, 2, …, N-1), and where a starting phase​ The transmission is linear across different transmitting antennas, making For example, as described in this paper, a common FMCW waveform can be multiplied by a phase code. This allows antennas to transmit concurrently at the same time and frequency resources, but each antenna can use a different phase code. In some cases, the phase code can be called a "slow-time phase code" because it is applied across chirps (or pulses) rather than across samples within the same chirp (or pulse). In some respects, phase decoding can be performed chirp-by-chirp rather than sample-by-sample.

[0231] At box 1920, the network device (or a component thereof) can receive at least one echo signal from one or more targets. For example, the at least one echo signal may include a target echo, which may include a delayed and attenuated copy of the transmitted chirp. The received signal may be mixed with the transmitted chirp, which may produce a complex sine wave that can be referred to as a beat signal.

[0232] At box 1930, the network device (or a component thereof) may mitigate (e.g., remove) Doppler ambiguity in the Doppler spectrum of at least one echo signal based on one or more Doppler spectral modes. For example, the Doppler spectral modes may be used to determine multiple ambiguity peaks (e.g., Figure 20 Which peak in the phase code (1635, 1645, 1655, 1665) corresponds to the real target? It is designed such that the peak corresponding to antenna Tx1 is a true peak in the peak set.

[0233] In some aspects, each of the multiple network devices is associated with a corresponding Doppler spectral punch vector. In some cases, each element of the Doppler spectral punch vector indicates whether the corresponding subband has been punched. In some examples, the pulse repetition frequency (PRF) of one or more of the multiple sense signals is increased or decreased to mitigate Doppler blurring.

[0234] Figure 20 This is a block diagram illustrating an example of a computing system 2000 that can be employed by the disclosed systems and techniques for enhancing DDM MIMO sensing based on Doppler spectral perforation. Specifically, ​ An example of a computing system 2000 is illustrated. This computing system can be any computing device, such as an internal computing system, a remote computing system, a camera, or any component thereof, wherein the components of the system communicate with each other using connection 2005. Connection 2005 can be a physical connection using a bus, or a direct connection to processor 2010, such as in a chipset architecture. Connection 2005 can also be a virtual connection, a networking connection, or a logical connection.

[0235] In some aspects, the computing system 2000 is a distributed system in which the functionality described in this disclosure can be distributed within a data center, multiple data centers, a peer-to-peer network, etc. In some aspects, one or more of the described system components represent a number of such components, each performing some or all of the functions attributed to the component. In some aspects, the components can be physical or virtual devices.

[0236] The example system 2000 includes at least one processing unit (CPU or processor) 2010 and a connection 2005, which communicatively couples to the various system components including the system memory 2015 (such as read-only memory (ROM) 2020 and random access memory (RAM) 2025) to the processor 2010. The computing system 2000 can include a cache of the processor 2010 in which some of the system components can be held in order to increase access speed. The computing system 2000 can further include one or more memory or storage components 2030, which can include nonremovable memory, removable memory, or a combination of both.

[0237] The processor 2010 can include any general purpose processor and a hardware service or software service, such as the services 2032, 2034, and 2036 stored in storage device 2030, configured to control the processor 2010 as well as a specific-purpose processor in which software instructions are incorporated into the actual processor design. The processor 2010 can be essentially a fully independent computing system containing multiple cores or processors, buses, memory controllers, caches, etc. The multi-core processor can be symmetric or asymmetric.

[0238] To enable user interaction, the computing system 2000 includes an input device 2045, which can represent any number of input mechanisms, such as a microphone for speech, a touch-sensitive screen for gesture or graphical input, keyboard, mouse, motion input, speech and the like. The computing system 2000 can also include output devices 2035, which can be one or more of a number of output mechanisms known to those of skill in the art. In some instances, multi-modal systems can enable a user to provide multiple types of input to communicate with the computing system 2000.

[0239] The computing system 2000 can include communications interface 2040, which can generally govern and manage the user input and system output. The communications interface can perform or facilitate receiving and / or sending wired or wireless communications using wired and / or wireless transceivers, including utilizing audio jacks / plugs, microphone jacks / plugs, universal serial bus (USB) ports / plugs, Apple ™ Lightning ™Port / Plug, Ethernet Port / Plug, Fiber Optic Port / Plug, Dedicated Wired Port / Plug, 3G, 4G, 5G, and / or other cellular data network wireless signal transfer, Bluetooth ™ Wireless signal transfer, Bluetooth ™ Low Power (BLE) wireless signal transfer, IBEACON ™ Wireless signal transfer, Radio Frequency Identification (RFID) wireless signal transfer, Near Field Communication (NFC) wireless signal transfer, Dedicated Short-Range Communication (DSRC) wireless signal transfer, 802.11 Wi-Fi wireless signal transfer, Wireless Local Area Network (WLAN) signal transfer, Visible Light Communication (VLC), Worldwide Interoperability for Microwave Access (WiMAX), Infrared (IR) communication wireless signal transfer, Public Switched Telephone Network (PSTN) signal transfer, Integrated Services Digital Network (ISDN) signal transfer, Ad hoc network signal transfer, Radio Wave signal transfer, Microwave signal transfer, Infrared signal transfer, Visible light signal transfer, Ultraviolet light signal transfer, wireless signal transfer along the electromagnetic spectrum, or some combination thereof.

[0240] The communication interface 2040 can also include one or more ranging sensors (e.g., LIDAR sensors, laser rangefinders, RF radar, ultrasonic sensors, and infrared (IR) sensors) configured to collect data and provide measurements to the processor 2010, whereby the processor 2010 can be configured to perform determinations and calculations needed to obtain various measurements of the one or more ranging sensors. In some examples, the measurements can include time of flight, wavelength, azimuth angle, elevation angle, distance, linear velocity, and / or angular velocity, or any combination thereof. The communication interface 2040 can also include one or more Global Navigation Satellite System (GNSS) receivers or transceivers for determining a location of the computing system 2000 based on one or more signals received from one or more satellites associated with one or more GNSS systems. GNSS systems include, but are not limited to, GPS in the United States, Global Navigation Satellite System (GLONASS) in Russia, BeiDou Navigation Satellite System (BDS) in China, and Galileo GNSS in Europe. There is no limitation on operating on any particular hardware arrangement, and thus the underlying features here can be readily replaced to obtain improved hardware or firmware arrangements as they are developed.

[0241] The storage device 2030 can be a non-volatile and / or non-transitory and / or computer-readable memory device and can be a hard disk or other type of computer readable medium such as a box tape, flash memory card, solid-state memory device, digital versatile disc, cassette, floppy disk, flexible disk, hard disk, magnetic tape, magnetic strip / magnetic stripe, any other magnetic storage medium, flash memory, memristor memory, any other solid-state memory, compact disc read-only memory (CD-ROM) optical disc, rewritable compact disc (CD) optical disc, digital video disc (DVD) optical disc, Blu-ray disc (BDD) optical disc, holographic optical disc, another optical medium, secure digital (SD) card, micro secure digital (microSD) card, memory stick ® card, smart card chip, EMV chip, subscriber identity module (SIM) card, mini / micro / nano / pico SIM card, another integrated circuit (IC) chip / card, random access memory (RAM), static RAM (SRAM), dynamic RAM (DRAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash EEPROM (Flash EPROM), cache memory (e.g., level 1 (LI) cache, level 2 (L2) cache, level 3 (L3) cache, level 4 (L4) cache, level 5 (L5) cache, or other (L#) cache), resistive random access memory (RRAM / ReRAM), phase change memory (PCM), spin-transfer torque RAM (STT-RAM), another memory chip or cartridge, and / or combinations thereof.

[0242] The storage device 2030 can include software services, servers, services, and the like that, when code defining such software is executed by the processor 2010, cause the system to perform a function. In some aspects, a hardware service that performs a particular function can include the software components stored in a computer-readable medium that are necessary to perform the function coupled with the necessary hardware components, such as a processor 2010, a connection 2005, an output device 2035, and the like, to perform the function. The term computer-readable medium includes, but is not limited to, portable or fixed storage devices, optical storage devices, and various other mediums capable of storing, containing or carrying instruction and / or data. A computer-readable medium can include a non-transitory medium in which data can be stored and which does not include carrier waves and / or transitory electronic signals propagating wirelessly or over wired connections. Examples of a non-transitory medium can include, but are not limited to, a magnetic disk or tape, optical storage media such as compact disk (CD) or digital versatile disk (DVD), flash memory, memories, or memory devices. A computer-readable medium can have stored thereon code and / or machine-executable instructions that can represent a procedure, function, subprogram, program, routine, subroutine, module, software package, class, or any combination of instructions, data structures, or program statements. A code segment can be coupled to another code segment or a hardware circuit by passing and / or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. can be passed, forwarded, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc.

[0243] In the description above, specific details are provided to provide a thorough understanding of the aspects and examples provided herein. However, a person of ordinary skill in the art will recognize that the application is not limited to the specific aspects and examples described above. Thus, although the illustrative aspects of the application have been described in detail above, it should be understood that various modifications can be made without departing from the scope of the application. Accordingly, the appended claims should not be construed to include only the aspects and examples described above, but rather should be construed to include all aspects and equivalents that are within the spirit and scope of the application. Various features and aspects of the above-described application can be used individually or jointly. Further, the application can be used in any number of environments and applications beyond the ones described herein without departing from the broader spirit and scope of the specification. Accordingly, the specification and drawings are to be regarded as illustrative in nature and not as restrictive. The methods described herein can be implemented by various means depending upon the application. For example, storage media can be used for implementing some steps of the methods. The term “storage media” includes one or both of computer-readable storage media and transitory media (e.g., carrier waves, electromagnetic signals, etc.). The computer-readable storage media includes all tangible and non-transitory media used to code and carry data.

[0244] For the sake of clarity, in some instances the techniques can be presented as including a specific sequence of steps or actions. However, the steps or actions can be rearranged or otherwise modified in some instances, and some instances can include additional steps or actions. For example, additional interlaces can be used, or not all described steps or actions can be used. Not all of the described components can be used. In some instances, additional components can be used. For example, circuitry, systems, networks, processes, and other components can be shown as components in block diagram form to avoid obscuring the aspects being presented. In other instances, well-known structures and techniques can be shown or discussed in a summary fashion.

[0245] Further, those skilled in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the aspects disclosed herein can be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans can implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

[0246] Various aspects can be described herein in terms of processes or methods being performed by functional building blocks, such as modules, circuits, or steps. However, a process that executes on one computing device, such as a processor, can effectively "operate" on portions of data to transform the data or create abstract data structures to represent more "concrete" data constructs. Other processes can transform the data. This disclosure describes and claims both hardware and software methods.

[0247] Processes and methods according to the above-described examples can be implemented using stored computer-executable instructions or computer-executable instructions accessed from a computer-readable medium. Such instructions can comprise, for example, instructions and data which cause or otherwise configure a general purpose computer, special purpose computer, or a processing device to perform a certain function or group of functions. Portions of computer resources used can be accessed over a network. Computer-executable instructions can be in, for example, binary, assembly language, a high-level language like C, or the like. Examples of computer-readable media that can be used to store instructions, information used, and / or information created during methods according to described examples include magnetic or optical disks, flash memory, USB devices provided with non-volatile memory, networked storage devices, and the like.

[0248] In some aspects, computer-readable storage devices, media, and memories can include cables or wireless signals containing bitstreams and the like. However, where mentioned, non-transitory computer-readable storage media expressly excludes media such as power supply, carrier waves, electromagnetic waves, and signals per se.

[0249] Those skilled in the art will understand that information and signals can be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that can be referenced throughout the above description can be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof consistent with the particular application, as would be understood by one of ordinary skill in the art.

[0250] The various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein can be implemented or performed with a hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof and can be embodied in any of a number of various forms. When implemented in software, firmware, middleware, or microcode, the program code or code segments (e.g., computer program products) can be stored in a computer-readable or machine-readable medium. A processor(s) can perform the necessary tasks. Examples of various shapes include: a laptop computer, a smart phone, a mobile phone, a tablet device, or other small form factor personal computers, personal digital assistants, rack-mounted devices, stand-alone devices, and the like. The functionality described herein can also be embodied in peripheral devices or in interposers. By way of further example, such functionality can also be implemented on circuit boards among different chips or different processes executing on a single device.

[0251] Instructions, media for conveying such instructions, computing resources for executing them, and other structures for supporting such computing resources are example components for providing the functionality described by the present disclosure.

[0252] The techniques described herein can also be implemented in electronic hardware, computer software, firmware, or any combination thereof. Such techniques can be implemented in any of a variety of devices such as general purposes computers, wireless communication device handsets, or integrated circuit devices having multiple uses such as by application in wireless communication device handsets and other devices. Any features described as modules or components can be implemented together in an integrated logic device or separately as discrete but interoperable logic devices. If implemented in software, the techniques can be realized at least in part by a computer-readable data storage medium comprising program code including instructions that, when executed, performs one or more of the methods, algorithms and / or operations described above. The computer-readable data storage medium can form part of a computer program product, which can include packaging materials. The computer-readable medium can comprise memory or data storage media, such as random access memory (RAM) such as synchronous dynamic random access memory (SDRAM), read-only memory (ROM), non-volatile random access memory (NVRAM), electrically programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, magnetic or optical data storage media, and the like. Additionally or in the alternative, the techniques can be realized at least in part by a computer-readable communication medium that carries or communicates program code in the form of instructions or data structures and that can be accessed, read, and / or executed by a computer, such as a propagated signal or wave.

[0253] The program code can be executed by a processor, which can include one or more processors, such as one or more digital signal processors (DSPs), general purpose microprocessors, application-specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Such a processor can be configured to perform any of the techniques described in this disclosure. A general-purpose processor can be a microprocessor; but in the alternative, the processor can be any conventional processor, controller, microcontroller, or state machine. A processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. Accordingly, the term “processor,” as used herein can refer to any of the foregoing structure, any combination of the foregoing structure, or any other structure or apparatus suitable for implementation of the techniques described herein.

[0254] Those of ordinary skill in the art will appreciate that the less than (“<”) and greater than (“>”) symbols or terms used herein can be replaced with less than or equal to (“ ”) and greater than or equal to (“ ”) symbols, respectively, without departing from the scope of this description.

[0255] Where components are described as being "configured to" perform certain operations, such configuration can be accomplished, for example, by designing electronic circuits or other hardware to perform the operation, by programming programmable electronic circuits (e.g., microprocessors, or other suitable electronic circuits) to perform the operation, or any combination thereof.

[0256] The phrase "coupled to" or "communicatively coupled to" means a direct or indirect physical connection between components, and / or a direct or indirect communication between components (e.g., connected via a wired or wireless connection and / or other suitable communication interface).

[0257] Claim language or other language reciting "at least one of a set or collection of items" and / or "one or more of a set or collection of items" indicates that a member of the set or a member of the collection can be included in the claim one time or more than one time. For example, the claim language "at least one of A and B" or "at least one of A or B" means A, B, or A and B. In another example, the claim language "at least one of A, B, and C" or "at least one of A, B, or C" means A, B, C, or A and B, or A and C, or B and C, or A and B and C. The language "at least one of a set or collection of items" and / or "one or more of a set or collection of items" does not limit the set or collection to a single item, even if the set or collection is listed with only one item. For example, the claim language "at least one of A and B" or "at least one of A or B" can mean A, B, or A and B, and can additionally include items not listed in the set of A and B.

[0258] Exemplary aspects of the present disclosure include:

[0259] Aspect 1. A network device of a plurality of network devices for wireless communication, the network device comprising: at least one memory; and at least one processor coupled to the at least one memory and configured to: output, for transmission, a sensing signal to sense one or more targets, wherein the sensing signal and at least one sensing signal transmitted by at least one other network device of the plurality of network devices comprise one or more phase codes and a same frequency modulated continuous wave (FMCW), and wherein each phase code of each sensing signal corresponds to one or more Doppler spectrum patterns; receive at least one echo signal from the one or more targets; and mitigate Doppler ambiguities in Doppler spectra from the at least one echo signal based on the one or more Doppler spectrum patterns.

[0260] Aspect 2. The network device of Aspect 1, wherein each network device of the plurality of network devices is one of a user equipment (UE) or a base station.

[0261] Aspect 3. The network device of any of aspects 1 or 2, wherein the sensing signal and the at least one sensing signal are transmitted at a same time and using a same one or more frequency resources.

[0262] Aspect 4. The network device of any of aspects 1-3, wherein a phase code of the sensing signal is different from at least one phase code of the at least one other network device.

[0263] Aspect 5. The network device of aspect 4, wherein the one or more Doppler spectrum patterns comprise contiguous empty subbands.

[0264] Aspect 6. The network device of aspect 4, wherein the one or more Doppler spectrum patterns comprise non-contiguous empty subbands.

[0265] Aspect 7. The network device of any of aspects 1-6, wherein a phase code of the sensing signal is the same as at least one phase code of the at least one other network device.

[0266] Aspect 8. The network device of aspect 7, wherein each network device of the plurality of network devices is associated with a respective Doppler spectrum puncturing vector.

[0267] Aspect 9. The network device of aspect 8, wherein each element of the Doppler spectrum puncturing vector indicates whether a corresponding subband is punctured.

[0268] Aspect 10. The network device of any of aspects 1-9, wherein the at least one processor is configured to increase or decrease a pulse repetition frequency (PRF) of one or more sensing signals of a plurality of sensing signals to mitigate the Doppler ambiguity.

[0269] Aspect 11. A method for wireless communication at a network device of a plurality of network devices, the method comprising: transmitting, by the network device, a sensing signal for sensing one or more targets, wherein the transmitted sensing signal and at least one sensing signal transmitted by at least one other network device of the plurality of network devices comprise one or more phase codes and a same frequency modulated carrier wave (FMCW), and wherein each phase code of each sensing signal corresponds to one or more Doppler spectrum patterns; receiving, by the network device, at least one echo signal from the one or more targets; and mitigating, by the network device, a Doppler ambiguity in a Doppler spectrum from the at least one echo signal based on the one or more Doppler spectrum patterns.

[0270] Aspect 12. The method of aspect 11, wherein each network device of the plurality of network devices is one of a user equipment (UE) or a base station.

[0271] Aspect 13. The method of any one of aspects 11 or 12, wherein the transmitted sensing signal and the at least one sensing signal are transmitted at the same time and using the same one or more frequency resources.

[0272] Aspect 14. The method of any one of aspects 11 to 13, wherein a phase code of the transmitted sensing signal is different from at least one phase code of the at least one other network device.

[0273] Aspect 15. The method of aspect 14, wherein the one or more Doppler spectrum patterns comprise contiguous empty subbands.

[0274] Aspect 16. The method of aspect 14, wherein the one or more Doppler spectrum patterns comprise non-contiguous empty subbands.

[0275] Aspect 17. The method of any one of aspects 11 to 16, wherein a phase code of the transmitted sensing signal is the same as at least one phase code of the at least one other network device.

[0276] Aspect 18. The method of aspect 17, wherein each network device of the plurality of network devices is associated with a respective Doppler spectrum puncturing vector.

[0277] Aspect 19. The method of aspect 18, wherein each element of the Doppler spectrum puncturing vector indicates whether a corresponding subband is punctured.

[0278] Aspect 20. The method of any one of aspects 11 to 19, wherein a pulse repetition frequency (PRF) of one or more sensing signals of a plurality of sensing signals is increased or decreased to mitigate the Doppler ambiguity.

[0279] Aspect 21. A non-transitory computer-readable medium of a network device of a plurality of network devices, the non-transitory computer-readable medium having instructions stored thereon that, when executed by at least one processor, cause the at least one processor to: output, for transmission, a sensing signal for sensing one or more targets, wherein the sensing signal and at least one sensing signal transmitted by at least one other network device of the plurality of network devices comprise one or more phase codes and a same frequency modulated carrier wave (FMCW), and wherein each phase code of each sensing signal corresponds to one or more Doppler spectrum patterns; receive at least one echo signal from the one or more targets; and mitigate a Doppler ambiguity in a Doppler spectrum from the at least one echo signal based on the one or more Doppler spectrum patterns.

[0280] Aspect 22. The non-transitory computer-readable medium of aspect 21, wherein each network device of the plurality of network devices is one of a user equipment (UE) or a base station.

[0281] Aspect 23. The non-transitory computer-readable medium of any one of aspects 21 or 22, wherein the sensing signal and the at least one sensing signal are transmitted at a same time and using a same one or more frequency resources.

[0282] Aspect 24. The non-transitory computer-readable medium of any one of aspects 21 to 23, wherein a phase code of the sensing signal is different from at least one phase code of the at least one other network device.

[0283] Aspect 25. The non-transitory computer-readable medium of aspect 24, wherein the one or more Doppler spectrum patterns comprise contiguous null subbands.

[0284] Aspect 26. The non-transitory computer-readable medium of aspect 24, wherein the one or more Doppler spectrum patterns comprise non-contiguous null subbands.

[0285] Aspect 27. The non-transitory computer-readable medium of any one of aspects 21 to 26, wherein a phase code of the sensing signal is the same as at least one phase code of the at least one other network device.

[0286] Aspect 28. The non-transitory computer-readable medium of aspect 27, wherein each network device of the plurality of network devices is associated with a respective Doppler spectrum puncturing vector.

[0287] Aspect 29. The non-transitory computer-readable medium of aspect 28, wherein each element of the Doppler spectrum puncturing vector indicates whether a corresponding subband is punctured.

[0288] Aspect 30. The non-transitory computer-readable medium of any one of aspects 21 to 29, wherein a pulse repetition frequency (PRF) of one or more sensing signals of the plurality of sensing signals is increased or decreased to mitigate the Doppler ambiguity.

[0289] Aspect 31. A network device of a plurality of network devices for wireless communication, the network device comprising one or more means for performing the operations of any of aspects 11 to 20.

[0290] 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 can 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."

Claims

1. A network device, of a plurality of network devices, for wireless communication, the network device comprising: at least one memory; and at least one processor coupled to the at least one memory and configured to: output, for transmission, a sensing signal for sensing one or more targets, wherein the sensing signal and at least one sensing signal transmitted by at least one other network device, of the plurality of network devices, comprise one or more phase codes and a same frequency modulated carrier wave (FMCW), and wherein each phase code of each sensing signal corresponds to one or more Doppler spectrum patterns; receive, from the one or more targets, at least one echo signal; and mitigate, based on the one or more Doppler spectrum patterns, Doppler ambiguity in a Doppler spectrum from the at least one echo signal.

2. The network device of claim 1, wherein each network device, of the plurality of network devices, is one of a user equipment (UE) or a base station.

3. The network device of claim 1, wherein the sensing signal and the at least one sensing signal are transmitted at a same time and using a same one or more frequency resources.

4. The network device of claim 1, wherein a phase code of the sensing signal is different from at least one phase code of the at least one other network device.

5. The network device of claim 4, wherein the one or more Doppler spectrum patterns comprise contiguous empty subbands.

6. The network device of claim 4, wherein the one or more Doppler spectrum patterns comprise non-contiguous empty subbands.

7. The network device of claim 1, wherein a phase code of the sensing signal is the same as at least one phase code of the at least one other network device.

8. The network device of claim 7, wherein each network device, of the plurality of network devices, is associated with a respective Doppler spectrum puncturing vector.

9. The network device of claim 8, wherein each element of the Doppler spectrum puncturing vector indicates whether a corresponding subband is punctured.

10. The network device of claim 1, wherein the at least one processor is configured to increase or decrease a pulse repetition frequency (PRF) of one or more sensing signals, of a plurality of sensing signals, to mitigate the Doppler ambiguity.

11. A method for wireless communication at a network device, of a plurality of network devices, the method comprising: transmitting, by the network device, a sensing signal for sensing one or more targets, wherein the transmitted sensing signal and at least one sensing signal transmitted by at least one other network device, of the plurality of network devices, comprise one or more phase codes and a same frequency modulated carrier wave (FMCW), and wherein each phase code of each sensing signal corresponds to one or more Doppler spectrum patterns; receiving, by the network device, from the one or more targets, at least one echo signal; and mitigating, by the network device, based on the one or more Doppler spectrum patterns, Doppler ambiguity in a Doppler spectrum from the at least one echo signal. ​ ​ 12. The method of claim 11, wherein each network device of the plurality of network devices is one of a user equipment (UE) or a base station.

13. The method of claim 11, wherein the transmitted sensing signal and the at least one sensing signal are transmitted at the same time and using the same one or more frequency resources.

14. The method of claim 11, wherein a phase code of the transmitted sensing signal is different from at least one phase code of the at least one other network device.

15. The method of claim 14, wherein the one or more Doppler spectral patterns comprise contiguous empty subbands.

16. The method of claim 14, wherein the one or more Doppler spectral patterns comprise non-contiguous empty subbands.

17. The method of claim 11, wherein a phase code of the transmitted sensing signal is the same as at least one phase code of the at least one other network device.

18. The method of claim 17, wherein each network device of the plurality of network devices is associated with a respective Doppler spectral puncturing vector.

19. The method of claim 18, wherein each element of the Doppler spectral puncturing vector indicates whether a corresponding subband is punctured.

20. The method of claim 11, wherein a pulse repetition frequency (PRF) of one or more sensing signals of the plurality of sensing signals is increased or decreased to mitigate the Doppler ambiguity.

21. A non-transitory computer-readable medium of a network device of a plurality of network devices, the non-transitory computer-readable medium having instructions stored thereon that, when executed by at least one processor, cause the at least one processor to: output, for transmission, a sensing signal for sensing one or more targets, wherein the sensing signal and at least one sensing signal transmitted by at least one other network device of the plurality of network devices comprise one or more phase codes and a same frequency modulated carrier wave (FMCW), and wherein each phase code of each sensing signal corresponds to one or more Doppler spectral patterns; receive at least one echo signal from the one or more targets; and mitigate a Doppler ambiguity in a Doppler spectrum from the at least one echo signal based on the one or more Doppler spectral patterns.

22. The non-transitory computer-readable medium of claim 21, wherein each network device of the plurality of network devices is one of a user equipment (UE) or a base station.

23. The non-transitory computer-readable medium of claim 21, wherein the sensing signal and the at least one sensing signal are transmitted at the same time and using the same one or more frequency resources.

24. The non-transitory computer-readable medium of claim 21, wherein a phase code of the sensing signal is different from at least one phase code of the at least one other network device.

25. The non-transitory computer-readable medium of claim 24, wherein the one or more Doppler spectral patterns comprise contiguous empty subbands.

26. The non-transitory computer readable medium of claim 24, wherein the one or more Doppler spectrum patterns comprise non-consecutive empty sub-bands.

27. The non-transitory computer readable medium of claim 21, wherein a phase code of the sensing signal is the same as at least one phase code of the at least one other network device.

28. The non-transitory computer readable medium of claim 27, wherein each network device of the plurality of network devices is associated with a respective Doppler spectrum puncturing vector.

29. The non-transitory computer readable medium of claim 28, wherein each element of the Doppler spectrum puncturing vector indicates whether a corresponding sub-band is punctured.

30. The non-transitory computer readable medium of claim 21, wherein a pulse repetition frequency (PRF) of one or more of the plurality of sensing signals is increased or decreased to mitigate the Doppler ambiguity.

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