Extension of root-MUSIC to non-ULA Array Configurations

In this paper we introduce a method for modelling the steering vector of an arbitrary array such that its steering vector can be expressed as the product of a characteristic matrix of the array itself and a vector with a Vandermonde structure containing the unknown parameter. We call this technique manifold separation. By exploiting this concept, we developed a novel version of the root-MUSIC algorithm for direction of arrival (DoA) estimation of sources. It can be applied to arbitrary 2-D array configurations. The proposed algorithm processes the data in element-space domain and does not require any transformation or array interpolation. The novel algorithm, named element-space root-MUSIC, provides computationally low complexity (search-free) DoA estimation and has close to CRB performance already at low SNRs