2-D DOA estimation of coexisting uncorrelated and coherent signals

The common two dimensional (2-D) direction of arrival (DOA) estimation algorithms for coexisting uncorrelated and coherent signals are based on the complex array structure, such as the uniform rectangular array, so the computational complexity is high and the array aperture is not utilized efficiently. By taking advantage of the L-shape array and adopting an efficient method to eliminate the Gaussian noise, a new 2-D DOA estimation method is proposed. Firstly, the DOAs of the uncorrelated signals are estimated and the influence of the coherent signals is eliminated by utilizing its characteristics. Then, the data covariance matrix containing the coherent information only is obtained by exploiting the Toeplitz property of the uncorrelated signals, and the DOAs of the coherent signals are estimated by the direction finding method based on the compressed sensing theory. Theoretical analysis and simulation results show that the proposed method has a small computational load, high array aperture as well as excellent estimation performance.