Passive entry/passive start systems implementing music algorithm based angle of arrival determinations for signals received via circular polarized antennas

摘要

An access system for a vehicle is provided and includes antennas and an access module. The antennas are configured to each receive a signal transmitted from a portable access device to the vehicle. One of the antennas is a circular polarized antenna. The access module is configured to: downconvert the received signal to generate an in-phase signal and a quadrature phase signal; execute a music algorithm to determine angles of arrival of the received signal as received at the antennas; determine a distance between the portable access device and the vehicle based on the angles of arrival; and permit access to the vehicle based on the distance.