基于空间差分平滑的非相关与相干信源数估计

Estimation of the Number of Uncorrelated and Coherent Signals Base on the Spatial Difference Smoothing

针对非相关信源与相干信源共存时信源数估计问题,提出了一种新的基于空间差分平滑的信源数估计算法。该算法首先利用SORTE法估计相互独立信源个数,结合非相关信源阵列导向矢量与噪声子空间正交关系特性,实现非相关信源数估计;其次基于空间差分法消除非相关信号并构造新矩阵,利用构造矩阵进行前向空间平滑,实现对相干信源解相干;最后利用SORTE法得到相干信源数估计。仿真实验结果验证了该算法的有效性。

The new spatial difference smoothing method is proposed for the number estimation of uncorrelated and coherent narrowbandsignalssimultaneously impinging on the far field of a uniform linear array. In the proposed method,the uncorrelated sources and coherent signal groupnumber is firstly estimated using the second order statistic of eigenvalues (SORTE)method. Theoretical analysis shows the coherent signals are not able to form peak in the MUSIC spectrum and the number of uncorrelated signals and coherent group can be obtained. Then the uncorrelated signals and noise can be eliminated from spatial differencessmoothing. A spatial differencing matrix that only contains the information of coherent signals is obtained. Finally thenumber of coherent signals is estimated based on the SORTE method. The theoretical analysis and simulationresults confirm the effectiveness of the method.