Abstract: A system includes first and second radar transceivers, a processor, and a non-transitory computer-readable medium storing machine instructions. The machine instructions cause the processor to determine a first frequency offset a1 and a first initial time offset ?initial;1 between a first clock signal for the first radar transceiver and a reference clock for the processor, and the processor determines a first clock drift for the first clock signal relative to the reference clock based on the frequency offset a1 and the time offset ?initial;1. The processor determines a second frequency offset a2 and a second initial time offset ?initial;2 between a second clock signal for the second radar transceiver and the reference clock, and a second clock drift for the second clock signal relative to the reference clock based on the frequency offset a2 and the time offset ?initial;2. The processor then compensates for the first and second clock drift.

Abstract: Described are method and systems that implement time frequency domain threshold interference and localization fusion to resolve interference issues in an automotive radar system, that produces spectrograms using Short-Time Fourier Transform (STFT) for all receiving antennas of the automotive radar system. For each STFT frequency a suppression threshold is determined. Interference is isolated for each STFT frequency by removing the interference from samples that are above the suppression threshold by using a filter. Direction of Arrival (DoA) is estimated for each interference spectrogram cell using measurements from all the receiving antennas. Interference samples are clustered using the DoA into epochs of chirps.

Abstract: A radar processor for processing a frame of radar data received from one or more targets, the frame of radar data having a carrier frequency and comprising a sequence of codewords with a codeword repetition interval, wherein the carrier frequency and the codeword repetition interval define an unambiguous velocity range, the radar processor configured to: receive the frame of radar data; transform the frame to obtain a velocity data array; apply a correction algorithm to the velocity data array to correct a Doppler shift of the frame to obtain a corrected array, wherein the correction algorithm comprises a set of Doppler correction frequencies corresponding to a set of velocity gates and at least one of the set of Doppler correction frequencies corresponds to a velocity gate outside the unambiguous velocity range; and perform range processing on the corrected array to obtain a range-Doppler map.

Abstract: In imaging radar, examples are directed to uses of multiple sets of transmit antenna included with transceiver circuitry, for transmitting in a plurality of modes. Transmissions may involve having at least one transmit antenna, from each of at least two of the multiple sets, to transmit continuous-wave energy concurrently (simultaneously) in one or more of the plurality of different modes. Transceiver circuitry may include multiple receive antennas which may be receiving reflections of the continuous-wave energy from various targets. Signals from the multiple receive antennas may route to signal processing circuitry. The signal processing circuitry may respond to the received reflections of the continuous-wave energy by assessing differences in antenna gain and/or phase due to transmit antenna position associated with the received reflections.

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: In accordance with a first aspect of the present disclosure, a radar system is provided, comprising: a plurality of receive channels; a first radar detector stage configured to detect, through said receive channels, at least one target using a detector threshold; a noise correlation determination unit configured to determine a noise correlation level indicative of noise correlation between the receive channels if the first radar detector stage has detected the target; a detector threshold adjustment unit configured to adjust the detector threshold in dependence on the noise correlation level determined by the noise correlation determination unit; a second radar detector stage configured to detect the target using the adjusted detector threshold. In accordance with a second aspect of the present disclosure, a corresponding method of operating a radar system is conceived.

Abstract: Exemplary aspects are directed to or involve a radar transceiver to transmit signal and receive reflected radar signals via a communication channel. The exemplary method includes radar receiver data processing circuitry that may be used to differentiate a subset of representations of the received signals. This differentiation may be used to select signals that are more indicative of target(s) having a given range than other ones of the received signals. The received signal's representations may then be compressed by using variable-mantissa floating-point numbers having mantissa values that vary based, at least in part, on at least one strength characteristic of the respective representations.

Abstract: Described are method and systems that implement time frequency domain threshold interference and localization fusion to resolve interference issues in an automotive radar system, that produces spectrograms using Short-Time Fourier Transform (STFT) for all receiving antennas of the automotive radar system. For each STFT frequency a suppression threshold is determined. Interference is isolated for each STFT frequency by removing the interference from samples that are above the suppression threshold by using a filter. Direction of Arrival (DoA) is estimated for each interference spectrogram cell using measurements from all the receiving antennas. Interference samples are clustered using the DoA into epochs of chirps.

Abstract: An apparatus configured to receive an input dataset, x, indicative of radar signals reflected from targets as received at a plurality of antenna elements; define a matrix, A, formed of direction-of-arrival-angle vectors, an, each direction-of-arrival-angle vector representing an expected response at the plurality of antenna elements of radar signals from one of the targets; define a signal amplitude vector s to represent expected complex amplitudes as received in the radar signals; define an objective function based on x, A and s; search for a set of direction of arrival angles for each of the plurality of targets by the repeated evaluation of the objective function for a plurality of candidate matrices based on matrix A; and wherein said search space comprises a plurality of discrete points, z, associated with the direction of arrival angles by a function of sin(?k).

Abstract: Aspects of the present disclosure are directed to radar transmissions and related componentry. As may be implemented in accordance with various embodiments, radar signals are generated and transmitted using both scanning and fixed beam analog signal codes concurrently/as combined for each radar signal. Reflections of the radar signals from a target are processed for ascertaining positional characteristics of the target.

Abstract: A mechanism is provided for determining an unambiguous direction of arrival (DoA) for radio frequency (RF) signals received by a sparse array. A DoA angle domain is split into hypothesis regions. The hypothesis regions are derived from the phase differences of the antenna element pairs used for the DoA angle estimate. In each hypothesis region, the ambiguous phase of antenna element pairs is unwrapped according to expected wrap-around. After unwrapping the phase, for each hypothesis region, a phasor is calculated by combining the individual antenna element pair phasors. The hypothesis region that obtains the phasor with a largest amplitude is selected as the most likely DoA region and the phase of the winning phasor is used as an unambiguous estimate for the DoA angle.

Abstract: Embodiments are directed to a method for determining velocity of an object. The method includes in response to two interleaved chirp sequences being sent towards the object, processing responsive chirps of each of the two interleaved chirp sequences independently from one another to produce respective Doppler-spectrum data sets, and calculating the velocity of the object based on the respective Doppler-spectrum data sets. Each of the interleaved chirp sequences being characterized by a common time spacing between respective chirps of the respective chirp sequence, and each chirp of one of the chirp sequences being offset by an amount of time that is different than the common time spacing.

Abstract: Aspects of the present disclosure are directed to radar signaling utilizing a non-uniform multi input/multi output (MIMO) antenna array including first and second uniform MIMO antenna arrays respectively having both sparsely-arranged transmitting antennas and sparsely-arranged receiving antennas. Communication circuitry is configured to determine a direction of arrival of reflections of radar signals transmitted by the transmitting antennas and received by the receiving antennas, by comparing the reflections received by the first MIMO array with the reflections received by the second MIMO array during a common time period (e.g., at the same time). Using this approach, the antenna arrays may be utilized to provide co-prime spacing/elements and to suppress ambiguities in received reflections based on alignment thereof.

Abstract: A mechanism is provided for determining an unambiguous direction of arrival (DoA) for radio frequency (RF) signals received by a sparse array. A DoA angle domain is split into hypothesis regions. The hypothesis regions are derived from the phase differences of the antenna element pairs used for the DoA angle estimate. In each hypothesis region, the ambiguous phase of antenna element pairs is unwrapped according to expected wrap-around. After unwrapping the phase, for each hypothesis region, a phasor is calculated by combining the individual antenna element pair phasors. The hypothesis region that obtains the phasor with a largest amplitude is selected as the most likely DoA region and the phase of the winning phasor is used as an unambiguous estimate for the DoA angle.

Abstract: A radar processor for processing a frame of radar data received from one or more targets, the frame of radar data having a carrier frequency and comprising a sequence of codewords with a codeword repetition interval, wherein the carrier frequency and the codeword repetition interval define an unambiguous velocity range, the radar processor configured to: receive the frame of radar data; transform the frame to obtain a velocity data array; apply a correction algorithm to the velocity data array to correct a Doppler shift of the frame to obtain a corrected array, wherein the correction algorithm comprises a set of Doppler correction frequencies corresponding to a set of velocity gates and at least one of the set of Doppler correction frequencies corresponds to a velocity gate outside the unambiguous velocity range; and perform range processing on the corrected array to obtain a range-Doppler map.

Abstract: A mechanism is provided to determine if a short-range automotive radar detection is a direct reflection or an indirect (also known as “multipath”) reflection from a physical target object. The multipath information is further used to perform a height estimation of the object. Embodiments provide a radar system having a range resolution smaller than a path difference between the direct reflection path and the indirect reflection path. Both range separation techniques and Doppler separation techniques are utilized to provide a reliable and accurate estimation of the height of the object.

Abstract: In imaging radar, examples are directed to uses of multiple sets of transmit antenna included with transceiver circuitry, for transmitting in a plurality of modes. Transmissions may involve having at least one transmit antenna, from each of at least two of the multiple sets, to transmit continuous-wave energy concurrently (simultaneously) in one or more of the plurality of different modes. Transceiver circuitry may include multiple receive antennas which may be receiving reflections of the continuous-wave energy from various targets. Signals from the multiple receive antennas may route to signal processing circuitry. The signal processing circuitry may respond to the received reflections of the continuous-wave energy by assessing differences in antenna gain and/or phase due to transmit antenna position associated with the received reflections.

Abstract: Exemplary aspects are directed to or involve a radar transceiver to transmit signal and receive reflected radar signals via a communication channel. The exemplary method includes radar receiver data processing circuitry that may be used to differentiate a subset of representations of the received signals. This differentiation may be used to select signals that are more indicative of target(s) having a given range than other ones of the received signals. The received signal's representations may then be compressed by using variable-mantissa floating-point numbers having mantissa values that vary based, at least in part, on at least one strength characteristic of the respective representations.

Abstract: Aspects of the present disclosure are directed to a method and/or apparatus involving frequency modulated continuous wave (FMCW) radar signals. As my be implemented in accordance with one or more embodiments, receiver circuitry is configured and arranged to receive a FMCW radar signal having an information signal embedded into a radar waveform, and to indicate a relationship in the FMCW radar signal between beat frequency magnitude and time delay. A filter processing circuit is configured and arranged to filter the information signal in the FMCW radar signal by applying a group delay function based on the relationship between beat frequency magnitude and time delay. Signal processing circuitry is configured and arranged to detect a remote object by using the filtered FMCW radar signal.

Abstract: Aspects of the present disclosure are directed to radar signaling utilizing a non-uniform multi input/multi output (MIMO) antenna array including first and second uniform MIMO antenna arrays respectively having both sparsely-arranged transmitting antennas and sparsely-arranged receiving antennas. Communication circuitry is configured to determine a direction of arrival of reflections of radar signals transmitted by the transmitting antennas and received by the receiving antennas, by comparing the reflections received by the first MIMO array with the reflections received by the second MIMO array during a common time period (e.g., at the same time). Using this approach, the antenna arrays may be utilized to provide co-prime spacing/elements and to suppress ambiguities in received reflections based on alignment thereof.