Abstract: Aspects of the present disclosure are directed to radar and radar processing. As may be implemented in accordance with one or more embodiments involving multi-input multi-output (MIMO) co-prime radar signals transmitted by a plurality of transmitters and reflected from at least one target, the reflected radar signals are processed by resolving ambiguities associated with a range-Doppler detection based on unique pulse repetition frequencies (PRF)s associated with respective chirp groups of the reflected radar signals. Phase compensation is applied to compensate for motion-induced phased biases and, thereafter, Doppler estimates are reconstructed to provide a dealiased version of the reflected radar signals.

Abstract: Aspects of the present disclosure are directed to radar communications with disparate pulse repetition intervals, as may be implemented with radar transmission, receiver and processing circuitry. As may be utilized in accordance with one or more embodiments herein, time division multiplexing (TDM) multi-input multi-output (MIMO) radar signals are transmitted by transmitting sets of successive radar signals, each set having a pulse repetition interval (PRI) that is different than the PRI of sets of radar signals transmitted in another one of the sets. Positional characteristics of a target may be ascertained based on the PRI used in each of the sets and on phase characteristics of ones of the radar signals reflected from the target.

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 distributed aperture radar system, apparatus, architecture, and method are provided for generating a completed virtual array aperture by using a radar control processing unit to construct a sparse forward-backward matrix from one or more sparse measurement array vectors and to generate beamforming outputs of a completed virtual array aperture by performing forward-backward matrix completion processing of the sparse forward-backward matrix to construct a completed forward-backward matrix by filling holes in the sparse MIMO virtual array aperture to suppress spurious sidelobes caused by holes in the sparse forward-backward matrix, thereby enabling computation of one or more super resolution direction of arrival (DoA) estimation values based on the completed forward-backward matrix.

Abstract: Aspects of the present disclosure are directed toward apparatuses and/or methods involving the communication of radar signals. Certain aspects involve communicating time division multiplexing (TDM) multi-input multi-output (MIMO) radar signals, having pulses with a chirp interval time (CIT) that is different for respective chirps. Positional characteristics of a target may be ascertained based upon both the CIT between each chirp in the communicated radar signals and the time between each corresponding chirp in received ones of the signals reflected by the target. Communication of the radar signals may involve utilizing a combination of antennas to provide a virtual aperture.

Abstract: A method and system are provided to resolve Doppler ambiguity and multiple-input, multiple-output array phase compensation issues present in Time Division Multiplexing MIMO radars by estimating an unambiguous radial velocity measurement. Embodiments apply a disambiguation algorithm that dealiases the Doppler spectrum to resolve the Doppler ambiguity of a range-Doppler detection. Phase compensation is then applied for corrected reconstruction of the MIMO array measurements. The dealiasing processing first forms multiple hypotheses associated with the phase corrections for the radar transmitters based on a measured radial velocity of a range-Doppler cell being processed. A correct hypothesis, from the multiple hypotheses, is selected based on a least-spurious spectrum criterion. Using this approach, embodiments require only single-frame processing and can be applied to two or more transmitters in a TDM MIMO radar system.

Abstract: Aspects of the present disclosure are directed to radar signal processing apparatuses and methods. As may be implemented in accordance with one or more embodiments, digital signals representative of received reflections of radar signals transmitted towards a target are mathematically processed to provide or construct a matrix pencil based on or as a function of a forward-backward matrix. Eigenvalues of the matrix pencil are computed and an estimation of the direction of arrival (DoA) of the target is output based on the computed eigenvalues.

Abstract: A linear chirp radar system, apparatus and method use a radar control processing unit to control an LFM radar front end which generates analog-to-digital (ADC) sample signals from one or more target return signals received in response to transmitted linear chirp radar signals, where the radar control processing unit is connected and configured to mitigate range migration by directly filtering the ADC samples using a modified Doppler filter that is tuned to fast-time scaled, slow-time frequencies to generate a focused ADC Doppler cube, and by applying a Fourier Transform on each Doppler cell in the focused ADC Doppler cube to generate a focused range-Doppler cube.

Abstract: A radar receiver comprising: an ADC (510) that samples analogue intermediate frequency, IF, signalling in order to generate digital signalling, wherein the digital signalling comprises a plurality of digital-values; a digital processor that populates a 2-dimensional array of bin-values based on the digital-values, such that: a first axis of the 2-dimensional array is a fast time axis and a second axis of the 2-dimensional array is a slow time axis; and a sampling-rate-adjuster that is configured to set a sampling rate associated with the bin-values in the 2-dimensional array based on an index of the slow time axis. The digital processor also performs DFT calculations on the bin-values in the 2-dimensional array along the fast time axis and the slow time axis in order to determine the range and velocity of any detected objects.

Abstract: A linear chirp radar system, apparatus and method use a radar control processing unit to control an LFM radar front end which includes a frequency-scanning transmit antenna and a frequency-scanning receive antenna which respectively sweep a transmit and receive energy focus across an angle space with each linear chirp signal, where the radar control processing unit processes digital output signals generated from target return signals received in response to transmitted linear chirp signals and extracts target range-angle information by applying time-frequency analysis processing to the digital output signals to generate a first range-angle map which includes range-biased angle information, and then applying a group delay compensation process to generate a second range-angle map which includes target range-angle information that is generated by selectively adjusting the range-biased angular information in the first range-angle map with an angular adjustment.

Abstract: A vehicle radar system, apparatus and method use a radar control processing unit to control an RF transmitter unit to generate a radiated beam by a long and medium range radar (LMRR) beam shaping antenna array which has a range coverage pattern with more power concentrated along a central direction axis for long range detection and less power spread off to sides of the central direction axis for medium range detection, wherein the LMRR beam shaping antenna array includes a plurality of transmit radiator elements stacked over a power dividing feeding network and separated by a conductive coupling aperture layer comprising a plurality of coupling apertures such that each transmit radiator element is aligned through a corresponding coupling aperture to a corresponding feeding line conductor from the power dividing feeding network.

Abstract: Aspects of the disclosure are directed to apparatuses, systems and methods for radar processing. As may be implemented in accordance with one or more aspects herein, an apparatus may include receiver circuitry to receive and sample radar signals reflected from a target, and processing circuitry to carry out the following. Representations of the reflections are transformed into the time-frequency domain where they are oversampled. The oversampled representations of the reflections are inversely transformed to provide resampled reflections. Positional characteristics of the target may then be ascertained by constructing a range response characterizing the target based on the resampled reflections.

Abstract: Aspects of the present disclosure are directed to radar and radar processing. As may be implemented in accordance with one or more embodiments involving multi-input multi-output (MIMO) co-prime radar signals transmitted by a plurality of transmitters and reflected from at least one target, the reflected radar signals are processed by resolving ambiguities associated with a range-Doppler detection based on unique pulse repetition frequencies (PRF)s associated with respective chirp groups of the reflected radar signals. Phase compensation is applied to compensate for motion-induced phased biases and, thereafter, Doppler estimates are reconstructed to provide a dealiased version of the reflected radar signals.

Abstract: A co-prime coded DDM MIMO radar system, apparatus, architecture, and method are provided with a reference signal generator (112) that produces a transmit reference signal; a plurality of DDM transmit modules (11) that produce, condition, and transmit a plurality of transmit signals over which each have a different co-prime encoded progressive phase offset from the transmit reference signal; a receiver module (12) that receives a target return signal reflected from the plurality of transmit signals by a target and generates a digital signal from the target return signal; and a radar control processing unit (20) configured to detect Doppler spectrum peaks in the digital signal, where the radar control processing unit comprises a Doppler disambiguation module (25) that is configured with a CPC decoder to associate each detected Doppler spectrum peak with a corresponding DDM transmit module, thereby generating a plurality of transmitter-associated Doppler spectrum peak detections.

Abstract: Aspects of the present disclosure are directed to radar signal processing apparatuses and methods. As may be implemented in accordance with one or more embodiments, digital signals representative of received reflections of radar signals transmitted towards a target are mathematically processed to provide or construct a matrix pencil based on or as a function of a forward-backward matrix. Eigenvalues of the matrix pencil are computed and an estimation of the direction of arrival (DoA) of the target is output based on the computed eigenvalues.

Abstract: Aspects of the disclosure are directed to apparatuses, systems and methods for radar processing. As may be implemented in accordance with one or more aspects herein, an apparatus may include receiver circuitry to receive and sample radar signals reflected from a target, and processing circuitry to carry out the following. Representations of the reflections are transformed into the time-frequency domain where they are oversampled. The oversampled representations of the reflections are inversely transformed to provide resampled reflections. Positional characteristics of the target may then be ascertained by constructing a range response characterizing the target based on the resampled reflections.

Abstract: Aspects of the present disclosure are directed to radar communications with disparate pulse repetition intervals, as may be implemented with radar transmission, receiver and processing circuitry. As may be utilized in accordance with one or more embodiments herein, time division multiplexing (TDM) multi-input multi-output (MIMO) radar signals are transmitted by transmitting sets of successive radar signals, each set having a pulse repetition interval (PRI) that is different than the PRI of sets of radar signals transmitted in another one of the sets. Positional characteristics of a target may be ascertained based on the PRI used in each of the sets and on phase characteristics of ones of the radar signals reflected from the target.

Abstract: A method and system are provided to resolve Doppler ambiguity and multiple-input, multiple-output array phase compensation issues present in Time Division Multiplexing MIMO radars by estimating an unambiguous radial velocity measurement. Embodiments apply a disambiguation algorithm that dealiases the Doppler spectrum to resolve the Doppler ambiguity of a range-Doppler detection. Phase compensation is then applied for corrected reconstruction of the MIMO array measurements. The dealiasing processing first forms multiple hypotheses associated with the phase corrections for the radar transmitters based on a measured radial velocity of a range-Doppler cell being processed. A correct hypothesis, from the multiple hypotheses, is selected based on a least-spurious spectrum criterion. Using this approach, embodiments require only single-frame processing and can be applied to two or more transmitters in a TDM MIMO radar system.

Abstract: Aspects of the present disclosure are directed toward apparatuses and/or methods involving the communication of radar signals. Certain aspects involve communicating time division multiplexing (TDM) multi-input multi-output (MIMO) radar signals, having pulses with a chirp interval time (CIT) that is different for respective chirps. Positional characteristics of a target may be ascertained based upon both the CIT between each chirp in the communicated radar signals and the time between each corresponding chirp in received ones of the signals reflected by the target. Communication of the radar signals may involve utilizing a combination of antennas to provide a virtual aperture.

Abstract: A co-prime coded DDM MIMO radar system, apparatus, architecture, and method are provided with a reference signal generator (112) that produces a transmit reference signal; a plurality of DDM transmit modules (11) that produce, condition, and transmit a plurality of transmit signals over which each have a different co-prime encoded progressive phase offset from the transmit reference signal; a receiver module (12) that receives a target return signal reflected from the plurality of transmit signals by a target and generates a digital signal from the target return signal; and a radar control processing unit (20) configured to detect Doppler spectrum peaks in the digital signal, where the radar control processing unit comprises a Doppler disambiguation module (25) that is configured with a CPC decoder to associate each detected Doppler spectrum peak with a corresponding DDM transmit module, thereby generating a plurality of transmitter-associated Doppler spectrum peak detections.