提出一種新的相干波束形成方法，利用內插變換對相干背景下的真實陣列進行虛擬平移，得到多個虛擬平移后的信號協方差矩陣；對其進行平均后，所得到的相干信號協方差矩陣具有滿秩性。利用一般的波束形成法求出最優權向量。該方法解決了五陣元均勻圓陣下二維相干信號的波束形成問題。計算機仿真表明該方法在小快怕數及低信噪比時能很好地抑制相干干擾，對期望信號和相干信號方向估計誤差具有較強的穩健性。
關 鍵 詞 均勻圓陣; 虛擬平移; 相干信號; 波束形成
中圖分類號 TN911 文獻標識碼 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