存在相干信号时的最优波束形成

Optimum beamforming for coherent signals

本文提出了一种新的存在相干信号时的最优波束形成方法。该方法首先利用估计得到的期望信号和相干信号的方向形成变换矩阵,去掉数据中的期望信号和相干信号成分,求得不相关干扰信号的子空间以及其正交子空间,然后得到期望信号和相干信号的合成导向矢量在该正交子空间中的投影矢量,并把该投影矢量作为自适应权矢量。经理论分析表明,这种方法基本上和理论上的最优方法相同。另外,该方法可以适用于任意的阵列结构,并且对期望信号和相干信号方向估计误差具有很强的稳健性。计算机仿真结果证实了本文方法的有效性。

This paper presents a new method of optimum beamforming in the presence of coherent signals. The method first uses estimates of the source directions to construct a transformation , which removes the desired signal and the coherent signals. The uncorrelated interference subspace and its orthogonal complementary space are obtained with the transformed data. The projected vector of the composite steering vector onto the orthogonal complementary space is gotten and used as the weight vector. The theoretical analysis indicates that the proposed method is nearly identical to the optimum method. The proposed method can been applied to an array of arbitrary geometry and is robust to the estimation errors of the source directions. Computer simulation results demonstrate the effectiveness of the proposed method.