Two-dimensional DOA estimation for non-circular sources

A two dimensional (2-D) DOA estimation method is proposed for non-circular sources in this paper. According to the non-circularity of the sources, we utilize both the receiving signal and its conjugate to estimate the DOA angles aiming at expanding the array virtually, which can improve the estimation properties at low signal to noise ratio (SNR) and small number of array elements. Then based on the principle of ESPRIT, the DOA angles are estimated. The proposed new method utilizes the properties of the receiving cross covariance matrix and simple pair matching method to cut down the computation load. Finally, a 2-D DOA estimation method for coherent sources is proposed via spatial smoothing techniques. Simulation results show that the proposed algorithm can estimate independent and coherent sources effectively and has much better performances than that of common ESPRIT algorithms.