基于特征波束形成的强弱信号波达方向与信源数估计方法

摘要

For the problem of the source number and Direction Of Arrivals (DOAs) estimation of the weak signals in the presence of the strong signals, a new method based on eigen beamforming for estimating source number and DOAs is proposed. Firstly, the eigenvectors of the spatial covariance matrix is sorted according to the descending order of the eigenvalues. Secondly, the spatial spectrum of each eigen beam is estimated in turn by the proposed equation. Finally, whether the signal source have or not is judged by the ration of the maximum value of the spatial spectrum to the mean value of the side-lobe peaks and the direction of arrival of the signal is obtained by the angle corresponding to the maximum value. Without the precise DOA knowledge and the iterative steps, the proposed method has the merits of the simpler computation and the more accuracy compared with RELAX and JJM. The effectiveness and the superiority are demonstrated by the simulation results and the measured data.%该文针对强弱信号并存时信源数和弱信号波达方向难以准确估计的问题,提出了一种基于特征波束形成的强弱信号波达方向与信源数同时估计方法.首先估计空域协方差矩阵,对其特征分解后按特征值从大到小调整特征矢量;然后从第1个特征矢量开始,由提出的估计式得到各特征波束的空间谱;最后,通过计算各空间谱的最大值与旁瓣谱峰平均值的比例判断有无信源,最大谱峰对应的角度即为该信源的波达方向估计.与RELAX和JJM方法相比,所提方法无需迭代步骤,无需强信号波达方向精确的先验知识,具有运算量小和弱信号估计精度高的优点,仿真和实测数据处理结果证明了方法的有效性和优越性.