基于均匀圆阵的压制式相干干扰DOA估计算法

DOA estimation algorithm of the suppressed coherent interference based on uniform circular array

针对导航抗干扰中一般干扰信号波达方向(direction-of-arrival, DOA)算法无法在均匀圆阵上有效地估计含有相干干扰的信号来向问题,提出了一种基于虚拟线阵的协方差矩阵重构的MUSIC算法。该算法通过对均匀圆阵进行模式空间变换,形成虚拟线阵,将模式空间变换后的数据协方差矩阵的所有行进行Toeplitz重构,并将所有Toeplitz矩阵构造成一个新的等效的满秩数据协方差矩阵,以此来达到解相干的目的。结合在虚拟线阵上的MUSIC算法,并通过多谱峰搜索算法直接得到空间谱的谱峰位置,从而完成对干扰来向的DOA估计。经仿真验证,该算法在存在相干信号且信号角度相隔30°左右的条件下,依旧能够对信号的波达方向进行有效估计。

In order to solve the problem that the general direction-of-arrival(DOA)algorithm cannot effectively estimate the direction of arrival of signals containing coherent interference on a uniform circular array,a MUSIC algorithm based on the reconstruction of covariance matrix of virtual linear array is proposed.This algorithm forms a virtual linear array by mode space transformation of the uniform circular array,and reconstructs all rows of the data covariance matrix after mode space transformation by Toeplitz.All Toeplitz matrices are constructed into a new equivalent full rank data covariance matrix to achieve the purpose of decoherence.Combined with the MUSIC algorithm on the virtual linear array,the spectral peak position of the spatial spectrum can be obtained directly through the multispectral peak search algorithm,thus completing the DOA estimation of the interference direction.Computer simulation results verified that the algorithm can still effectively estimate the direction of arrival of signals when there is coherent signal and the signal angle is about 30°apart.