Abstract: A TDM MIMO FMCW radar comprises an array of physical receivers with a first spacing in a first direction and a plurality of physical transmitters arranged with a second spacing in said first direction. A virtual array signal of a range-Doppler bin relating to a scene with a moving object is processed by a phase compensation method, which introduces a phase ambiguity between the subarrays. For each of the subarrays, a frequency spectrum is computed of those elements of the compensated virtual array signal which correspond to consecutive virtual antenna elements generated by physical receivers belonging to the same row. Next, an amplitude-peak frequency is identified jointly for the frequency spectra of the subarrays. Next, a residual phase shift between a pair of the subarrays is determined by comparing, at the amplitude-peak frequency, the respective phases of the frequency spectra.

Abstract: A TDM MIMO FMCW radar comprises an array of physical receivers with a first spacing in a first direction and a plurality of physical transmitters arranged with a second spacing in said first direction. A virtual array signal of a range-Doppler bin relating to a scene with a moving object is processed by a phase compensation method, which introduces a phase ambiguity between the subarrays. A positive or negative spatial phase change rate with respect to the first direction is computed based on elements of the compensated virtual array signal corresponding to one subarray at a time. From this, based on the spacings, a spatial phase change between a pair of the subarrays is predicted. Next, a residual phase shift between said pair of subarrays is determined by comparing an actual phase shift of the compensated virtual array signal and the predicted spatial phase shift.

Abstract: A method for interference reduction between radar units. The method is performed by a radar unit and comprises: receiving one or more radar frames, wherein the one or more radar frames correspond to one or more respective time intervals during which the radar unit was activated to transmit and receive signals to produce data samples of the one or more radar frames; and determining whether the one or more radar frames have a higher presence of data samples that are subject to interference from other radar units in a first half of their corresponding time intervals than in a second, later, half of their corresponding time intervals. In case the presence is higher in the first half of their corresponding time intervals, a scheduled time interval of an upcoming radar frame to be produced by the radar unit is postponed, and otherwise it is advanced.

Abstract: A method for classifying tracks in radar detections of a scene acquired by a stationary radar unit, comprises: acquiring radar detections of the scene using the static radar unit; feeding at least a portion of the radar detections into a tracker module for producing track-specific feature data indicating a specific track in the scene, feeding at least a portion of the radar detections into a scene model comprising information about scene-specific features aggregated over time, and information indicating areas in the scene with expected ghost target detections and areas with expected real target detections, wherein at least a subset of the scene-specific features is determined from the radar detections; classifying the specific track as belonging to a real target or to a ghost target by relating the specific track to a position in the scene model.

Abstract: A method for mapping a static scene using a stationary radar unit operative to transmit radar signals towards a scene, the stationary radar unit comprises a set of receiver antennas configured to detect radar signals from arbitrary directions, and the stationary radar unit is configured to measure target velocity in discrete velocity bins, the method comprising: continuously collecting radar signals over time to detect a static scene using the set of receiver antennas; constructing an occupancy map of the static scene using confirmed detections determined from the collected radar signals, where confirmed detections are detections with radar signal strength exceeding a detection threshold and with velocity falling in a zero velocity bin and detections with radar signal strength exceeding the detection threshold and with a non-zero velocity sufficiently low to cause spill over information in the same bin as detections falling in the zero velocity bin.

Abstract: A method for interference reduction between radar units. The method is performed by a radar unit and comprises: receiving one or more radar frames, wherein the one or more radar frames correspond to one or more respective time intervals during which the radar unit was activated to transmit and receive signals to produce data samples of the one or more radar frames; and determining whether the one or more radar frames have a higher presence of data samples that are subject to interference from other radar units in a first half of their corresponding time intervals than in a second, later, half of their corresponding time intervals. In case the presence is higher in the first half of their corresponding time intervals, a scheduled time interval of an upcoming radar frame to be produced by the radar unit is postponed, and otherwise it is advanced.