基于互协方差的L型嵌套阵列二维波达方向估计

The direction of arrival (DOA)estimation for L-shaped uniform antenna array is limited by low resolution, number of incident signals and signal-to-noise ratio. A two-dimensional DOA estimation algorithm for L-shaped nested array based on cross-covariance matrix is proposed to solve this problem. In the proposed algorithm, the cross-covariance matrixes of different sub-arrays are used to generate longer virtual arrays without redundant elements, which eliminate the noise. To cope with the coherent signals of virtual arrays, several equivalent covariance matrixes are constructed by using the signal of virtual arrays and its conjugate signal. The rotational invariance technique is used to deal with the equivalent covariance matrixes to obtain the angle of incident signals, and the angles are matched by using the uniqueness of equivalent signal vectors of virtual arrays. The effectiveness of the proposed algorithm for DOA estimation was verified. The simulated results show that the proposed algorithm can achieve better DOA estimation performance in low SNR environment and identify more spatial sources compared to the L-shaped uniform array with the same number of array elements.