Noncircular Signal DOA Estimation with Reduced Dimension MUSIC for Coprime Linear Array

In this paper, we propose a direction-of-arrival (DOA) estimation method of noncircular signals by combining noncircular property and coprime linear array signal processing. This method can significantly extend the array aperture and increase its degree of freedom (DOF). For non-circular signals, it usually needs two-dimensional spectrum peak search, which needs amount of computation to get the estimates of incident angles and non-circular phases. To reduce the computational complexity, a reduced-dimension MUSIC method is used here for the DOA estimation of noncircular signals without estimate the non-circular phase. The angle estimation performance of the proposed method is much better than that of the conventional MUSIC method for uniform linear array (ULA) and coprime linear array (CLA). Furthermore, the proposed method works well without estimating the noncircular phases and a locally spectrum peak search is used to further decrease the computational complexity. Extensive simulations have been conducted and the results show that the proposed method can achieve accurate DOA estimation under different SNR conditions.