基于相关函数的低维度宽带波束形成算法

Low-Dimension Broadband Beamformer Algorithm Based on Correlation Function

为了降低波束的旁瓣和主瓣宽度并提高抗干扰能力,本文提出了一种基于相关函数的低维度宽带波束形成算法。首先,对宽带信号进行FFT变换以将其转化为多个子带的窄带信号;其次,基于最小方差(MV)准则并利用相关函数将子带信号的干扰-噪声协方差矩阵重构为相关矩阵,以达到有效抑制噪声和干扰的目的;然后,利用降维算法以降低相关矩阵的复杂度,并利用拉格朗日乘数法来求解最优权矢量;最后,利用切比雪夫滤波器对最优权矢量进行静态加权调整,以期获得更高的阵列增益和更低的旁瓣电平。仿真结果表明:该算法的计算复杂度较小,主瓣宽度变窄1度左右,最佳输出信干噪比提高了约-1.3 d B,同时旁瓣幅度有效降低。

In order to reduce the sidelobe,and main lobe widths of the beam to improve the anti-interference capability,a low-dimension broadband beamformer algorithm based on correlation function is proposed.Firstly,the broadband signal is transformed into narrowband signal with multiple sub bands by FFT transformation.Secondly,based on minimum variance cri-terion,interference-noise covariance matrix of sub band signal is reconstructed into correlation matrix by using correlation function,so as to suppress noise and interference effectively.Then,dimension reduction algorithm is used to reduce the com-plexity of correlation matrix,and Lagrange multiplier method is used to solve the optimal weight vector.Finally,Chebyshev filter is used to adjust the optimal weight vector to obtain higher array gain and lower sidelobe level.The simulation results show that the algorithm has smaller computational complexity,and the main lobe width is narrower about 1 degree.The opti-mal output signal-to-noise ratio is smaller about-1.3 dB,and the sidelobe amplitude is lower.