Efficient 2-D DOA Estimation for Incoherently Distributed Sources with an L-shaped Array

Direction-of-arrival (DOA) estimation with sufficient accuracy and efficiency for incoherently distributed (ID) sources remains a challenging problem. To this end, a computationally efficient two-dimensional (2-D) DOA estimation algorithm for ID sources is proposed, where the generalized array manifold (GAM) of an L-shaped array established on the first-order Taylor series approximation is exploited. By extracting the first column of the array cross-covariance matrix to eliminate the impacts of additive noise and angular spreads, and further applying the conjugate symmetry operation to enlarge the effective array aperture, the proposed algorithm provides an improved estimation performance with closed-form expressions. Moreover, a proper pairing criterion is designed to avoid the ambiguity problem, and simulation results are presented to show the superiority and effectiveness of the proposed algorithm.