A novel DOA estimation method and its focusing matrices for multiple wide-band sources

In this paper a novel method for high resolution estimation of directions of arrival (DOA) of multiple wide-band sources is proposed. The key point of the coherent signal-subspace (CSS) is focusing which maps the signal subspaces of narrow-band components of a wide band signal onto a single signal subspace. The frequency-dependent modeling (FDM) introduces basic functions into array output signal to process directly the wide-band signal. We present a new DOA estimation method, named CSSFDM, which applies the coherent signal-subspace focusing to the frequency-dependent modeling. And several classes of focusing matrices used in CSSFDM are proposed in this paper. They are the diagonal matrix, the rotational signal-subspace (RSS) matrix and the robust focusing matrix. The estimation performance comparisons for various class of focusing matrices are also presented by computer simulation.