利用单次快拍实现相干信源二维测向的新算法

A New Method for Estimating 2-D DOA in Coherent Source Environment Using Single Snapshot

针对复杂电磁干扰背景下相干信源二维波达方向的快速估计问题,根据垂直阵列系统特点,利用单次快拍数据在3个不同维度构造了数据矩阵实现解相干,并结合ESPRIT算法实现了二维DOA的快速估计.该算法仅利用单次快拍数据,不需要进行协方差矩阵的计算,并将二维DOA估计问题转化为3个一维DOA估计,可同时在3个维度并行处理,因此运算量大大降低,利于工程实现.针对算法存在阵列孔径损失和仅采用一次快拍数据量导致的估计误差偏大问题,利用非圆信号特征和同相位数据叠加,改善了算法的估计性能,提高了阵列自由度.数值仿真验证了本文算法及提高估计精度对策的有效性.

In order to estimate two-dimensional direction-of-arrival（DOA）of coherent signal sources fast in complex electromagnetic interference environment,the paper reconstructs three data matrixes which use the observed data vector directly and can realize decorrelation in three different dimensions according to the characteristic of three orthogonal linear arrays.Combined with ESPRIT algorithm,the 2-D DOA can be estimated fast.Using one single snapshot,the proposed algorithm doesn＇t need to calculate covariance matrix.The problem of estimating 2-D DOA can be transformed to three 1-D DOA estimations which can be carried out synchronously,so the algorithm reduces calculation amount and this is helpful to project implementation.The proposed algorithm exists the problem of aperture loss and estimation error caused by one single snapshot.Using the characteristic of noncircular signals and the accumulation of the same phase data,the method can improve the degree of freedom of array and estimation performance.The simulation results show the effectiveness of the proposed algorithm and the countermeasures.