Abstract: A velocity ambiguity resolving method and an echo signal processing apparatus are provided. The method includes: calculating, for first echo signals respectively received by at least two receive antennas in the N receive antennas, a first estimate of a direction of arrival formed by the at least two receive antennas and a first target, where the first echo signals are echo signals formed after transmit signals sent by a same transmit antenna in a time division transmit mode are reflected by the first target; separately performing, by using the first estimate, angle compensation on M second echo signals received by a first receive antenna, to obtain M first compensated echo signals; and performing velocity estimation based on at least two first compensated echo signals, to obtain a velocity of the first target.

Abstract: A beat frequency signal processing method includes determining a two-dimensional (2D) time frequency spectrogram of a beat frequency signal based on a sampled sequence of the beat frequency signal, where the 2D time frequency spectrogram indicates a relationship between a frequency and a time of the beat frequency signal; performing matching between the 2D time frequency spectrogram of the beat frequency signal and a plurality of theoretical 2D time frequency spectrograms to determine, as a target 2D time frequency spectrogram, a theoretical 2D time frequency spectrogram whose matching degree is greater than or equal to a preset threshold. The plurality of theoretical 2D time frequency spectrograms are 2D time frequency spectrograms of the beat frequency signal, under combinations of a plurality of flight times and a plurality of Doppler frequency offsets, that are calculated based on a frequency sweep curve of the frequency modulated signal.

Abstract: An apparatus for radar synchronization may include a local radar device configured to transmit and receive radar signals; a wireless device configured to wirelessly transmit and receive data; at least one processor operably coupled to the wireless device and the radar device, and the at least one processor configured to perform a method including obtaining local radar information regarding one or more radar pulses sent and/or received by the local radar device; and obtaining neighboring radar information associated with radar pulses sent and/or received from one or more neighboring radar devices; and updating a radar data structure using the obtained local and neighboring radar information, wherein the radar data structure comprises radar information for each of a plurality of radar pulses transmitted by the local radar device and/or the one or more neighboring radar devices.

Abstract: Systems and methods are provided for subway personnel detection. An ultra-wideband (UWB) based detection of objects in subway tunnels may include transmitting UWB signals into an area within a subway tunnel, the area including one or more tracks traversed by trains running in the subway tunnel, receiving UWB signals within the area, and processing received UWB signals to enable detecting objects within the area. The processing may include identifying received UWB signals corresponding to echoes of the transmitted UWB signal transmitted by the detection devices, and detecting based on the echoes of the transmitted UWB signals when an object is present within the area. The object may be assessed, such as to determine when the object represents an intrusion within the area of the subway tunnel.

Abstract: An in-vehicle radar signal control method includes: determining a target interference area of a first vehicle, a vehicle in the target interference area interfering with an in-vehicle radar signal of the first vehicle; determining vehicles in the target interference area as a first vehicle cluster, and determining strength of in-vehicle radar signals of vehicles in the first vehicle cluster; determining whether a new second vehicle enters the target interference area; and in response to a determination that the second vehicle enters the target interference area, obtaining an adjustment signal; the adjustment signal indicating one or more of: increasing or reducing strength of the in-vehicle radar signal of the first vehicle, adjusting a travel speed of the first vehicle, and adjusting a travel direction of the first vehicle.

Abstract: A radar system includes transmitter and receiver antennas positioned to illuminate and receive reflections from a ground surface, a processor, and a non-transitory computer-readable medium. The processor obtains ground reflections, the corresponding ranges, and measured radial velocities, and determines a set of test ego velocities. For each test ego velocity and ground reflection, the processor generates a test radial velocity. The processor determines an absolute difference between the test radial velocity and the measured radial velocity, and whether the absolute difference satisfies a criterion. In response to satisfying the criterion, the absolute difference is accumulated into a total cost for the test ego velocity. After each ground reflection and test ego velocity is analyzed, the processor compares the total costs for the test ego velocities to obtain a smallest total cost and corresponding test ego velocity. The test ego velocity is an ego velocity of the radar system.

Abstract: A vehicle control system may include a controller that detects an object outside a vehicle, calculates an angle based on a ratio of a relative speed between the object and the vehicle to a speed of the vehicle, and updates a phase curve reflecting a phase distortion of an input signal based on the calculated angle.

Abstract: The present disclosure is directed to a traffic signal apparatus communication system and methods of communicating traffic information to vehicles using same. The traffic signal apparatus communication system includes a traffic signal apparatus for providing a message to a vehicle. The apparatus includes at least one spatially encoded marker, and the vehicle is configured to receive returns of a radar signal from the spatially-encoded marker. At least one controller of the vehicle is configured to determine the message encoded by the spatially-encoded marker based on the returns and to control the vehicle based on the message. The message may include a value indicating a time to a transition of a new state of the traffic signal apparatus, where the new state includes emission of light from one of a first light source, a second light source, or a third light source of the traffic signal apparatus.

Abstract: In an FMCW-based fill-level measurement device, the fill-level value can be compensated with regard to component tolerances. A diagnosis unit of the fill-level measurement device compares the clock rate of the signal-generating PLL with the sampling rate of the analog/digital converter and determines a first compensation factor. With the aid of the first compensation factor, the determined fill-level value can be compensated with regard to these sampling or clock rates without any external high-precision reference source having to be used for this purpose.

Abstract: According to one embodiment, a radar device includes a transmission module including a transmission antenna and first integrated circuits, a reception module including a reception antenna and second integrated circuits, and a third integrated circuit. Each of the first integrated circuits includes first transmission circuits, first reception circuits, and a first signal generation circuit. Each of the second integrated circuits includes second transmission circuits, second reception circuits, and a second signal generation circuit. The third integrated circuit includes third transmission circuits, third reception circuits, and a third signal generation circuit.

Abstract: A method for locating a communication device borne by a user in proximity to a vehicle in order to trigger at least one function of said vehicle, the method especially including, in a locating phase, steps of detection of a set of obstacles, called “current” obstacles, of identification of the communication device in the set of current obstacles and of location of the identified communication device among the obstacles of the set of obstacles.

Abstract: A multi-chip MIMO radar system includes a plurality of transmitters and a plurality of receivers. Each of the pluralities of transmitters and receivers are arranged across a plurality of circuit chips. The multi-chip MIMO radar system includes a central processor configured to receive data from the plurality of circuit chips. The plurality of circuit chips generates sets of selected range, Doppler, and virtual receiver data. The central processor is operable to process the sets of selected range, Doppler, and virtual receiver data to produce selected range detection and angular resolvability of targets.

Abstract: A location system for locating workers including a plurality of light detectors mounted at known locations and configured to detect light from one or more workers, and a processing system configured to determine locations of the workers using the light detected by the light detectors. There is also disclosed a wearable device for locating a worker including a wireless transceiver, and a wearable device light source and/or one or more reflective elements. There is also disclosed a method for locating workers including detecting light from one or more workers using a plurality of light detectors mounted at known locations, and determining locations of the workers using the light detected by the light detectors.

Abstract: Embodiments of systems and methods for estimating direction of arrival are disclosed. A device includes a signal processing unit that includes processing circuitry and memory coupled to the processing circuitry, where the processing circuitry includes multiple vector processing units, each vector processing unit configured to receive an antenna input vector, receive an angular spectrum vector, retrieve a first and second weighting vectors from the memory, generate a processed antenna input vector by performing a circular convolution of the antenna input vector with the first weighting vector, generate a processed angular spectrum vector by performing a circular convolution of the angular spectrum vector with the second weighting vector, and generate a refined angular spectrum vector, which indicates angular position of one or more radar targets, by applying a non-linear activation function to a sum of the processed antenna input vector and the processed angular spectrum vector.

Abstract: A radar detector employs parameterized subchannel analysis for discrimination of radar signals. Specifically, the signal processing of the radar detector includes a subchannel processor for evaluating programmable sub-bands of a channel for enhanced pattern identification. The subchannel processor specifically incorporates multiple digital demultiplexing stages, producing N signal subchannels at selectable frequencies. The subchannels are decimated from the original sampling frequency to a selectable lower sample frequency, e.g. using a cascaded integrator-comb filter, and then filtered, e.g. using a finite impulse response filter. The resulting sub channels 0 to N?1 are delivered for Neural Network assessment. Importantly, the subchannel frequencies, decimation rates and IIR filter profiles may be selectively adjusted by the control circuits to emphasize relevant patterns to be extracted by the neural network from a received radar signal.

Abstract: A radar signal processing method includes: extracting a first chirp sequence signal of a first carrier frequency and a second chirp sequence signal of a second carrier frequency from a radar signal received through an array antenna in a radar sensor; generating a first range-Doppler map by performing frequency conversion on the first chirp sequence signal; detecting a first target cell corresponding to a first target in the first range-Doppler map; determining a first ambiguous Doppler velocity of the first target based on first frequency information of the first target cell; determining a first range of an unambiguously measurable Doppler velocity through the first chirp sequence signal; estimating second ambiguous Doppler velocities based on the first ambiguous Doppler velocity and the first range; and determining a Doppler velocity of the first target by performing partial frequency conversion on the second chirp sequence signal based on the second ambiguous Doppler velocities.

Abstract: This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media, for radio frequency (RF) sensing in the millimeter-wave frequency spectrum that can be performed over multiple phases. During a session setup phase, a radar initiator identifies one or more wireless stations (STAs) that are capable of radar ranging and sets up a radar measurement session that includes at least one of the identified STAs. During a measurement negotiation phase, the radar initiator performs a respective beamforming training operation with each STA and indicates, to each STA, one or more parameters associated with the radar measurement session. During a radar measurement phase, the radar initiator transmits radar setup information to, and receives ranging information from, each STA. In some aspects, the radar initiator may perform an object detection operation that indicates a location of an object associated with the ranging information received from each radar STA.

Abstract: An extension of the LoRa modulation with an improved ranging mode. A master and a slave device exchange a request and a reply that contain sequences of chirps that are carefully aligned in time, frequency, and preferably also phase, such that the master device can ascertain the propagation delay to the slave by demodulating the reply. Request and reply include chirps having different slopes, preferably slopes of equal absolute value and opposite sign. The slope diversity permits an unbiased estimation of the Doppler shift.

Abstract: There is provided a radio wave absorber including a magnetic powder and a binder, in which a volume filling rate of the magnetic powder in the radio wave absorber is 35% by volume or less, a transmission attenuation amount is 8.0 dB or more, and a reflection attenuation amount is 8.0 dB or more.

Abstract: Disclosed is a method and apparatus for processing a radar signal by correcting a phase distortion. The method includes generating radar data based on a radar transmission signal transmitted through an array antenna of a radar sensor based on a frequency modulation model and a radar reception signal received through the array antenna as the radar transmission signal is reflected by a target, correcting the radar data using a correction vector for correcting a feedline error occurring due to a feedline delay difference between channels of the array antenna, and estimating a direction of arrival corresponding to the corrected radar data using a direction matrix reflecting a phase shift of the corrected radar data according to frequency modulation characteristics of the frequency modulation model.