基于半实值Capon的高效波达方向估计算法

摘要

子空间类超分辨波达方向(DOA)估计算法需预先估计信号个数，当信号个数估计错误时，其性能会严重下降。该文提出一种新颖的半实值Capon(SRV-Capon)DOA估计算法。该算法继承了Capon算法无需信号个数估计的优点并克服了现存实值算法仅适用于中心对称阵列(CSA)的缺点。相比于Capon算法，SRV-Capon仅利用阵列接收数据协方差矩阵的实部求逆构建空间谱函数，实现了谱值计算的半实值化并将谱搜索的范围压缩至原来的一半，从而至少降低约75%的计算量。理论分析和仿真实验证明了该算法的有效性。%Subspace based Direction-Of-Arrival (DOA) estimators require usually the number of sources to be known in advance. If the number of sources is incorrectly estimated, the performance of those methods is able to deteriorate significantly. This paper presents a novel efficient Semi-Real-Valued Capon (SRV-Capon) algorithm for DOA estimation with unknown number of signals. Compared with state-of-the-art real-valued techniques suitable for only Centro-Symmetrical Arrays (CSAs), the proposed method can be used with arbitrary arrays. Unlike conventional Capon with heavy complex computations, SRV-Capon exploits only the real part of the array output covariance matrix, leading to a real-valued spectral search over only half of the total angular field-of-view, which hence reduces about 75% computational complexity. Theoretical analysis and simulations demonstrate the effectiveness of the proposed approach.