提出一種新的相干波束形成方法，利用內(nèi)插變換對(duì)相干背景下的真實(shí)陣列進(jìn)行虛擬平移，得到多個(gè)虛擬平移后的信號(hào)協(xié)方差矩陣；對(duì)其進(jìn)行平均后，所得到的相干信號(hào)協(xié)方差矩陣具有滿秩性。利用一般的波束形成法求出最優(yōu)權(quán)向量。該方法解決了五陣元均勻圓陣下二維相干信號(hào)的波束形成問題。計(jì)算機(jī)仿真表明該方法在小快怕數(shù)及低信噪比時(shí)能很好地抑制相干干擾，對(duì)期望信號(hào)和相干信號(hào)方向估計(jì)誤差具有較強(qiáng)的穩(wěn)健性。
關(guān) 鍵 詞 均勻圓陣; 虛擬平移; 相干信號(hào); 波束形成
中圖分類號(hào) TN911 文獻(xiàn)標(biāo)識(shí)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