RESOLVING DOPPLER AMBIGUITY IN TDM-MIMO RADARS BASED ON PHASE AT PEAK

    公开(公告)号:US20240103129A1

    公开(公告)日:2024-03-28

    申请号:US18446012

    申请日:2023-08-08

    Applicant: Axis AB

    CPC classification number: G01S7/356 G01S13/36

    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.

    SYSTEMS AND METHOD FOR ADAPTIVE RADAR FRAME FILTERING

    公开(公告)号:US20240230878A9

    公开(公告)日:2024-07-11

    申请号:US18483122

    申请日:2023-10-09

    Applicant: Axis AB

    CPC classification number: G01S13/538

    Abstract: A system adaptively filters out a representation of an object from a radar frame captured by a radar device, where a maximum signal strength at zero velocity is obtained in a range bin comprising a detection of the object in range Doppler representations of a set of radar frames captured during a time period before the radar frame. A motion vector is obtained representing a determined magnitude and direction of motion of the radar device at the time when the radar frame was captured. The motion of the radar device is due to an oscillatory movement of the radar device. A range Doppler representation of the radar frame is produced and a direction vector representing a direction from the radar device to the object is determined. A radial relative velocity between the object and the radar device is determined based on the obtained motion vector and the determined direction vector.

    Method and devices for radar interference reduction

    公开(公告)号:US11630183B2

    公开(公告)日:2023-04-18

    申请号:US17216749

    申请日:2021-03-30

    Applicant: Axis AB

    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.

    Resolving doppler unambiguity in TDM-MIMO radars based on spatial phase change rate

    公开(公告)号:US12146981B2

    公开(公告)日:2024-11-19

    申请号:US18358215

    申请日:2023-07-25

    Applicant: Axis AB

    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.

    SYSTEMS AND METHOD FOR ADAPTIVE RADAR FRAME FILTERING

    公开(公告)号:US20240134031A1

    公开(公告)日:2024-04-25

    申请号:US18483122

    申请日:2023-10-08

    Applicant: Axis AB

    CPC classification number: G01S13/538

    Abstract: A system adaptively filters out a representation of an object from a radar frame captured by a radar device, where a maximum signal strength at zero velocity is obtained in a range bin comprising a detection of the object in range Doppler representations of a set of radar frames captured during a time period before the radar frame. A motion vector is obtained representing a determined magnitude and direction of motion of the radar device at the time when the radar frame was captured. The motion of the radar device is due to an oscillatory movement of the radar device. A range Doppler representation of the radar frame is produced and a direction vector representing a direction from the radar device to the object is determined. A radial relative velocity between the object and the radar device is determined based on the obtained motion vector and the determined direction vector.

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