A novel wideband DOA estimation method using direction-free focusing matrix

In this paper, a novel DOA estimation method without angles pre-estimating for Wideband Signals is proposed. The main idea is to design a novel Direction-Free focusing matrix using the decomposed representation of the array manifold matrix, where the angle parameter is separated from the array geometry and the frequency parameter. The focusing matrix is derived using a method similar to RSS. The novel method also uses the Toeplitz approximation algorithm to improve the estimation performance. The proposed method combines the RSS method and Toeplitz approximation algorithm, and does not require initial angles, so it can be called Toep-DFRSS method. The performance of Toep-DFRSS and other major methods is compared through computer simulations. The simulations show that Toep-DFRSS method has a better resolution performance and estimation accuracy than conventional RSS method, especially in the case of low SNR.