说明：  常规DOA谱估计music算法在多径环境下失效，SVD算法利用最大特征值对应的特征矢量重新构造奇异值矩阵，可以成功估计相干信号。
(Conventional music spectrum estimation algorithm for DOA in multipath environment, failure, SVD algorithm using the maximum eigenvalue of the feature vector corresponding to re-construct singular value matrix, can be successfully estimated coherent signal.)