关键词: 稀疏表示, 波达方向估计, 高分辨, 协方差矩阵, 相关信号, 快速极大似然算法

Abstract:

The performance of the L₁-norm-based sparse representation of array covariance vectors(L₁-SRACV) algorithm significantly degrades with the number of samples decreasing. This paper analyzes the essential cause of this performance degradation and proposes a new direction of arrival(DOA) estimation method based on the fast maximum likelihood(FML) algorithm. Firstly, the FML algorithm is employed to estimate the covariance matrix, which attenuates the instability of the small eigenvalues of the covariance matrix. Then the sparse representation model based on the FML is formulated for DOA estimation and finally, optimized by removing the diagonal elements of the covariance matrix to obtain better performance. Simulation results indicate that our method outperforms the L₁-SRACV with a higher accuracy and detection possibility, particularly under small samples support.

Key words: sparse representation, DOA estimation, high-resolution, covariance matrix, correlative signal, fast maximum likelihood algorithm