非圆信号与圆信号共存下的快速方位估计算法*

针对非圆信号和圆信号共存时，信号的波达方向估计算法运算量较大的问题，提出了一种可同时估计非圆信号和圆信号DOA的快速算法。首先，利用观测数据及其复共轭构造中心复共轭对称矩阵，通过双映射定理可将该矩阵转换为实矩阵；然后，利用多级维纳滤波，无需计算阵列协方差矩阵及对其进行特征分解，仅通过对接收的实数据矩阵递推可快速求出观测数据的信号子空间；最后，利用酉ESPRIT算法的实值性，不必谱峰搜索，在保证DOA估计精度的同时可大大降低算法的计算复杂度。仿真结果验证了算法的有效性。

Fast DOA estimation under the coexistence of both noncircular and circular sources

The existed algorithms had high computational complexity under the coexistence of both noncircular and circular sources, aiming at this situation, this paper proposed a fast algorithm. Firstly, through the reconstruction of observed data and its conjugate, central complex Hermitian matrix could convert into real matrix just by the theorem of double mapping. Secondly, through the recursion of real matrix with multistage Wiener filter(MSWF) , it could obtain the signal subspace of observed data, and it avoided the estimation of covariance matrix and its eigendecomposition. Finally, using the real feature of unitary ESPRIT algorithm, without the search of spectrum peak, the computational load of algorithm became less than before at the condition of keeping higher precision of DOA estimation. The computer simulation confirms the validity and the accuracy of the proposed algorithm.