Broadband beamspace DOA estimation with application to interfering sources suppression

An approach to direction-of-arrival estimation for multiple broadband farfield signals using constant mainlobe response beamspace preprocessing structure is proposed. A set of beamformers with constant mainlobe response is designed to cover the spatial sector of interest using optimal array pattern synthesis technique. Second-order cone programming method ensures that the synthesized beam patterns are constant within the main beam region while controlling the sidelobe shapes. Numerical results show that the proposed beamspace DOA estimator maintain good DOA estimation and spatial resolution capability in the scenario of strong out-of-band interfering sources by forming a notch in the direction of the interfering source.