Noncircularity-Based DOA Estimation for Incoherently Distributed Sources With Gain-Phase Uncertainties

In this work, we propose an efficient method for the direction of arrival (DOA) estimation of strictly noncircular incoherently distributed (ID) sources, taking into account gain-phase uncertainties and assuming that a portion of the array is well-calibrated. The proposed method uses the first-order Taylor expansion to construct an augmented generalized array manifold (GAM) that exploits the noncircularity property of the signals. Subsequently, the DOAs and gain-phase uncertainties are estimated by exploiting the array shift-invariance. Additionally, the angular spreads are estimated based on the central moments of their angular distributions. To gauge the performance of the discussed estimators, we establish a benchmark by deriving the Cramér-Rao bound (CRB) for the concerned DOA estimation problem. Generally, the proposed method presents a comprehensive and efficient solution for parameter estimation of strictly noncircular ID sources, addressing gain-phase uncertainties and accommodating various angular distributions. The simulations serve to validate the superiority of the proposed method.