Polynomial-rooting based fourth-order MUSIC for direction-of-arrival estimation of noncircular signals

A polynomial-rooting based fourth-order cumulant algorithm is presented for direction-of-arrival (DOA) estimation of second-order fully noncircular source signals, using a uniform linear array (ULA). This algorithm inherits all merits of its spectral-searching counterpart except for the applicability to arbitrary array geometry, while reducing considerably the computation cost. Simulation results show that the proposed algorithm outperforms the previously developed closed-form second-order noncircular ESPRIT method, in terms of processing capacity and DOA estimation accuracy, especially in the presence of spatially colored noise.