Patent attributes
In a direction estimator, a horizontal array maximum likelihood estimator calculates first maximum likelihood values corresponding to NW angles in a first direction by performing a maximum likelihood estimation process on the first direction using signals received by a first virtual linear array and extracts first candidate angles of arrival of incoming waves in the first direction. A vertical array maximum likelihood estimator calculates second maximum likelihood values corresponding to the NW angles in a second direction by performing a maximum likelihood estimation process on the second direction using signals received by a second virtual linear array and extracts second candidate angles of arrival of incoming waves in the second direction. A horizontal/vertical maximum likelihood estimator estimates, using the first and second candidate angles of arrival, angles of arrival of the NW incoming waves in a two-dimensional plane extending in the first and second directions.