Broadband DOA estimation using frequency invariant beamforming

A new method of direction-of-arrival (DOA) estimation for multiple broadband farfield signals is presented. The technique uses a beamspace preprocessing structure based on frequency invariant beamforming. Specifically, a set of beam-shaping filters focus the received array data in the time domain, thereby avoiding the need for frequency decomposition. Hence, the proposed method is conceptually different from most other broadband DOA estimators, which require frequency decomposition. Numerical results are presented to demonstrate the use of the new method and compare it with conventional coherent signal subspace methods.