基于均匀圆阵的相干信号波束形成方法

提出一种新的相干波束形成方法，利用内插变换对相干背景下的真实阵列进行虚拟平移，得到多个虚拟平移后的信号协方差矩阵；对其进行平均后，所得到的相干信号协方差矩阵具有满秩性。利用一般的波束形成法求出最优权向量。该方法解决了五阵元均匀圆阵下二维相干信号的波束形成问题。计算机仿真表明该方法在小快怕数及低信噪比时能很好地抑制相干干扰，对期望信号和相干信号方向估计误差具有较强的稳健性。
关 键 词 均匀圆阵; 虚拟平移; 相干信号; 波束形成
中图分类号 TN911 文献标识码 A
Beamforming of Coherent Signals Based on Uniform Circular Array
ZHANG Yang1，ZOU Zhou1，LÜ Ze-jun2，GONG Xi-ying1
(1. School of Electronic Engineering, Univ. of Electron. Sci. & Tech. of China Chengdu 610054; 2. Southwest China Institute of Electronic Technology Chengdu 610036)
Abstract In this paper a new method is proposed in order to suppress the coherent interference. First, utilizing the interpolate method, the real array can be virtually shifted under coherent interference, several covariance matrice are gererated after the virtual shifting. By averaging the previous results, a new covariance matrix is obtained. It is a full rank matrix. Then optimal weights are calculated using a common beamforming method. This method solves beamforming of 2-D coherent sources with a five-sensor uniform circular array. Simulation results confirm the availability of the new method in case of small data samples and low SNR. Moreover the proposed method is robust to the estimation errors of signal directions.
Key words uniform circular array; virtual shift; coherent signal; beamforming