采用局部搜索的二维DOA估计

针对酉旋转不变估计信号参数(Unitary-ESPRIT)算法估计精度较低的问题,提出了一种采用局部搜索实现的非相干信源二维波达方向(2-D DOA)估计方法.该方法首先利用实特征矢量近似值估计导向矩阵,然后利用矩阵Kronecker积性质以及阵列旋转不变特性获得自动配对的角度估计值,降低了2-D DOA初始估计复杂度,实现了对Unitary-ESPRIT算法的改进;接着,采用一维局部搜索法对该初始估计结果进行优化,提高了低信噪比下的2-D DOA估计精度.仿真实验结果表明,相较于传统的Unitary-ESPRIT算法,所提方法在DOA估计精度和成功率上具有明显的优势,特别是在低信噪比以及快拍数较少条件下,因此该方法能够在计算复杂度和估计性能之间取的较好的折中.

Two-dimensional DOA estimation based on local searching

To improve the estimation accuracy of the unitary estimation-of signal parameter via rotational techniques(Unitary-ESPRIT) method,a local searching-based method is proposed for two-dimensional (2D) direction-of-arrival(DOA) estimation of incoherent sources. First,the real eigenvector approxima―tion is used to estimate steering matrices. Second,the matrix Kronecker product properties and the charac―ter of the array rotational invariance are used to acquire the automatic matching angle estimation. There―fore,the computational load of the initial 2-D DOA estimation can be reduced efficiently and the Unitary-ESPRIT algorithm is improved significantly. Then the one-dimensional local searching is exploited to opti―mize initial results,which can efficiently improve the precision of angel estimation in low signal-to-noise ratio( SNR) . The simulation results verify that the proposed method has obvious superiority over the preci―sion and successful rate of DOA estimation compared with the original Unitary-ESPRIT method,especially in the condition of low SNR and fewer snapshots,so it can get a better tradeoff between computational com―plexity and estimation performance.