Extended-aperture DOA estimation with unknown number of sources

Most of the existing direction-of-arrival (DOA) estimation methods require a priori knowledge of the source number, and can only estimate M- 1 sources with M sensors. A novel technique for a sparse signal reconstruction framework is proposed, which is unbiased and can extend the array aperture effectively. As a result, the proposed technique can not only estimate 2(M- 1) sources with M sensors, but also provide improved resolution and estimation accuracy. It can even obtain DOA estimation without knowing the number of sources.