Mutual coupling effects among the array elements can degrade the performance of the beamformer seriously. In this paper, we propose a novel robust adaptive beamforming method, which is robust against unknown mutual coupling. The main idea is to reconstruct the interference-plus-noise covariance matrix (IPNCM) with the estimated eigenvector and eigenvalue corresponding to the interference. The eigenvector lies in the intersection of two special subspaces. The first subspace is the signal-plus-interference (SPI) subspace got from the sample covariance matrix (SCM). The second subspace, which is interference subspace, can be obtained by integrating the conduction matrix in each interference angular sector. According to the correlation between the estimated eigenvector and SPI subspace, the eigenvalues corresponding to each interference are determined. Therefore, the IPNCM is reconstructed. The desired signal steering vector (SV) is estimated by a similar method. Simulation results show that the proposed beamformer outperforms other methods in the presence of unknown mutual coupling.

阵元之间的相互耦合效应会严重降低波束形成器的性能。在本文中，我们提出了一种新颖的鲁棒自适应波束成形方法，该方法对未知互耦合具有鲁棒性。主要思想是用估计的特征向量和干扰对应的特征值重建干扰加噪声协方差矩阵（IPNCM）。特征向量位于两个特殊子空间的交集处。第一个子空间是从样本协方差矩阵 (SCM) 得到的信号加干扰 (SPI) 子空间。第二个子空间，即干扰子空间，可以通过对每个干扰角扇区中的传导矩阵进行积分得到。根据估计的特征向量与SPI子空间的相关性，确定每个干扰对应的特征值。因此，IPNCM 被重建。所需信号导向向量 (SV) 由类似方法估计。仿真结果表明，在存在未知互耦合的情况下，所提出的波束形成器优于其他方法。