US Patent No. 10,690,780

SELF-CALIBRATING ANGLE OF ARRIVAL SYSTEM


Patent No. 10,690,780
Issue Date June 23, 2020
Title Self-calibrating Angle Of Arrival System
Inventorship Radivoje Zarubica, Salt Lake City, UT (US)
Samuel C. Kingston, Salt Lake City, UT (US)
Larry S. Thomson, Salt Lake City, UT (US)
Bing Shen, Salt Lake City, UT (US)
Assignee L3 Technologies, Inc., New York, NY (US)

Claim of US Patent No. 10,690,780

1. A method, performed by an angle of arrival node in an angle of arrival system, for self-calibrating using a calibration node to thereby enable estimating an angle of arrival of a signal emitted by a node at an unknown location, the method comprising:receiving, at each of a plurality of antennas of an antenna array, a first signal emitted by a calibration node having a known location relative to the antenna array, the antennas being coupled to a modem via an RF chain;
generating, by the modem, a first covariance matrix representing phase differences of the first signal received at each of the antennas;
based on the known location of the calibration node, calculating a correction matrix that represents phase rotation caused by the RF chain;
receiving, at each of the plurality of antennas of the antenna array, a second signal emitted by a node at an unknown location;
generating, by the modem, a second covariance matrix representing phase differences of the second signal received at each of the antennas; and
applying the correction matrix to the second covariance matrix to remove the phase rotation caused by the RF chain.