A low-complexity estimator for incoherently distributed sources with narrow or wide spread angles

In this paper, a concept of contrast of eigenvalues (COE) is introduced to describe the diversity of the eigenvalues of signal covariance matrix. Based on the COE, a novel algorithm is proposed to estimate the central direction of arrival (DOA) and the angular spread of an incoherently distributed (ID) source. Using the proposed method, it is shown that the parameters of not only the narrowly but also the widely spread sources may be accurately obtained with low computational cost. The numerical examples are given to examine the performance of the COE-based estimator under various environments and show that it is indeed effective for both narrowly and widely spread ID sources.