Robust wideband DOA estimation

Within the last decade there has been a growing interest in developing techniques for the estimation of the Direction Of Arrival (DOA) of wavefronts carrying wideband signals. The Coherent Signal-Subspace Method (CSM) is one of the most largely adopted technique and it is based upon the so-called focusing matrices. In the literature. several focusing matrices have been proposed and the most effective of them often require preliminary DOA estimation. Furthermore. classical design techniques do not take into account the fact that estimated DOAs may differ from the actual ones oil which the manifold should be focused. In this paper we propose a novel focusing matrix design technique. It is shown that some classical methods leave room for further optimization of the available degrees of freedom, that are exploited here to create a CSM robust against DOA estimation errors and which does not require any preliminary DOA estimation.