| CPC G01S 7/403 (2021.05) [G01S 13/931 (2013.01); G01S 2013/93271 (2020.01)] | 20 Claims |
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1. A receiver comprising:
azimuth angle phase difference first estimation circuitry configured to
input a plurality of first reception signal groups each including first reception signals received at a plurality of first reception antennas that are part of a first linear array antenna, a number of the first reception signals being larger than a number of incoming waves by one, and
apply a first annihilation filter (AF) to the first reception signal groups to estimate azimuth angle phase differences of the incoming waves for respective of the first reception antennas, the estimate of azimuth angle phase differences for the first reception antennas being based on phases that occur at zeros of a transfer function of the first AF;
azimuth angle phase difference second estimation circuitry configured to
input a plurality of second reception signal groups each including second reception signals received at a plurality of second reception antennas that are part of a second linear array antenna arranged at a height that is different than the first linear array antenna, a number of the second reception signals being larger than the number of the incoming waves by one, and
apply a second AF to the second reception signal groups to estimate azimuth angle phase differences of the incoming waves for respective of the second reception antennas, the estimate of the azimuth angle phase differences of the incoming waves for the second reception antennas being based on phases that occur at zeros of a transfer function of the second AF;
incoming wave signal first estimation circuitry that estimates amplitudes and phases of signals of the incoming waves that arrive at a reference first reception antenna that is included in the first linear array antenna, based on azimuth angle phase differences of incoming waves among the first reception antennas estimated by the azimuth angle phase difference first estimation circuitry and the first reception signals;
incoming wave signal second estimation circuitry that estimates amplitudes and phases of signals of incoming waves arriving at a reference second reception antenna that is included in the second linear array antenna, based on the azimuth angle phase differences of the incoming waves among the second reception antennas estimated by the azimuth angle phase difference second estimation circuitry and the second reception signals;
elevation angle phase difference estimation circuitry that estimates phase differences that correspond to the height for the incoming waves as elevation angle phase differences, based on the signals estimated by the incoming wave signal first estimation circuitry that arrive at the reference first reception antenna and the signals estimated by the incoming wave signal second estimation circuitry that arrive at the reference second reception antenna; and
incoming direction two-dimensional estimation circuitry that is configured to
estimate elevation angles of incoming directions of incoming waves based on the elevation angle phase differences estimated by the elevation angle phase difference estimation circuitry, and
estimate azimuth angles of incoming directions of incoming waves based on the azimuth angle phase differences estimated by the azimuth angle phase difference first estimation circuitry or the azimuth angle phase difference second estimation circuitry.
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