A system and method for generating communications waveforms that can operate in congested frequency spaces and in applications in which the receiver is moving with respect to the transmitter is provided. In one or more examples, each symbol to be encoded and transmitted is converted into a sequence of frequency chirps. The sequence of frequencies used by the sequence of chirps is based on the symbol that is to be encoded. Each chirp can have a center frequency, and the frequency can be swept over the duration of the chirp. In this way each chirp can have a varying frequency over the duration of the chirp, but the phase of the chirp can be continuous throughout the duration of the chirp. The bandwidth and sweep rate of the chirp can be based on the expected maximum velocity of the receiver and the transmitter relative to one another.

A system for estimating a distance between vehicles may include an oscillator, a transmitter, a receiver, a summing circuit, a signal analyzer, a tunable phase shifter, a distance estimator, and/or a vehicle identifier. The oscillator may generate a generated oscillating signal, transmitted by the transmitter. The receiver may receive a processed signal derived by a system of a second vehicle. The summing circuit may add the generated oscillating signal to the received signal to produce the updated oscillating signal. The signal analyzer may detect a spike in amplitude associated with the updated oscillating signal. The tunable phase shifter may shift a phase of the generated oscillating signal by an incremental phase shift amount until a spike in amplitude is detected. The distance estimator may estimate the distance between the first vehicle and the second vehicle based on a total phase shift amount and the predetermined wavelength.

An axial displacement angle estimation device repeatedly calculates an axial displacement angle based on the detection result of the radar apparatus. The axial displacement angle estimation device extracts the axial displacement angle included in a predetermined extraction angle range among a plurality of axial displacement angles, and calculate an average value of the extracted plurality of axial displacement angles to be an axial displacement angle average value. The axial displacement angle estimation device determines, based on the axial displacement angle average value, whether a predetermined allowable condition is met. The axial displacement angle estimation device utilizes, when determined that the predetermined allowable condition is met, the axial displacement angle average value as an estimation result of the axial displacement angle.

Operating a police radar detector to suppress nuisance radar alerts due to received signals that are not police radar signals includes receiving electromagnetic signals; mixing received electromagnetic signals with a local oscillator signal that is swept at a constant sweep rate; and accumulating a virtual image of the signal environment represented by received electromagnetic signals. Analysis of the virtual image is performed for signals suspected of being nuisance signals that could result in nuisance radar alert so that any nuisance signals within the virtual image can be identified and ignored by the alarm portion of the police radar detector.

A chip-implementation of a millimeter wave MIMO radar comprises transmitters for transmitting short bursts of digitally modulated radar carrier signals and receivers for receiving delayed echoes of those signals. Various signal formats defined by the number of bits per transmit burst, the transmit burst duration, the receive period duration, the bitrate, the number of range bins, and the number of bursts per scan, facilitate the choice of modulating bit patterns such that when correlating for target echoes over an entire scan, the correlation codes for different ranges and different transmitters are mutually orthogonal or nearly so. In the event of imperfect orthogonality, simple orthogonalization schemes are revealed, such as subtraction of strong already-detected target signals for better detecting weaker signals or moving targets that are rendered non-orthogonal by their Doppler shift.

A method for controlling a radar apparatus that detects an object using frequency modulation includes: performing first reception of a radio wave in a state where transmission of a radio wave for detecting the object is stopped, to obtain a first reception signal; performing second reception of a radio wave in a state where the transmission of the radio wave is stopped, to obtain a second reception signal, after the performing of the first reception; acquiring a strength of a difference signal between the first reception signal and the second reception signal; comparing the strength with a threshold value; and starting the transmission of the radio wave in a case where the strength is equal to or less than the first threshold value in the comparison.

The learning device learns the target detection model used in the radar device. The learning device includes an acquisition unit, a learning data generation unit, and a learning processing unit. The acquisition unit acquires a reception signal generated based on the received wave and a tracking signal generated based on the reception signal from the radar device. The learning data generation unit generates learning data using the reception signal and the tracking signal. The learning processing unit learns a target detection model that detects a target from the reception signal, using the learning data.

A frequency band state determining method and a related device are provided. The method includes: A detection apparatus determines an intermediate frequency signal based on a detected interfering signal in an environment and an oscillation signal that belongs to a first frequency band. The detection apparatus performs first processing on the intermediate frequency signal, to obtain a first detection result, and when the first detection result indicates that the first frequency band is busy, the detection apparatus performs second processing on the intermediate frequency signal, to obtain a second detection result. The detection apparatus determines a state of the first frequency band based on the second detection result. The detection apparatus may be a radar, and the radar may work in a use scenario of a cooperative radar.

A range measurement device includes a signal processor configured to fit a signal, which is obtained by inverse correlating in frequency domain echo waves which are reflected by targets and returned with pulse waves which are frequency-modulated and transmitted toward the targets, with exponential functions whose arguments have real parts and imaginary parts using Prony method.

A vehicle (AV) includes a radar sensor and a hardware logic component. The radar sensor receives a radar return from a driving environment of the vehicle and outputs radar data that is indicative of the return to the hardware logic component. The hardware logic component further receives data indicative of a velocity of the vehicle from a sensor mounted on the vehicle. The hardware logic component is configured to employ synthetic aperture radar (SAR) techniques to compute a three-dimensional position of a point on a surface of an object in the driving environment of the vehicle based upon the radar data and the velocity of the vehicle.