基于虚拟阵元信号重构的嵌套阵稳健波束形成

Robust beamforming of nested array based on virtual elements signal reconstruction

由于嵌套阵中部分阵元间距远大于信号半波长,可能导致高旁瓣和栅瓣等问题。因此,通过利用均匀子阵进行信号波达方向(direction of arrival,DOA)估计,重构出虚拟阵元的接收信号,从而构建一个虚拟的稠密均匀阵列,大幅增加了波束形成算法自由度。通过估计信号功率,重构虚拟均匀阵列的干扰加噪声协方差矩阵(interference plus noise covariance matrix,INCM),可得虚拟均匀阵列的波束形成权矢量。仿真实验表明,相比其他波束形成方法,所提算法主瓣宽度小、旁瓣电平低、收敛速度快、抗干扰能力强。

The inter-sensor spacing of some elements in the nested array is far larger than half a wavelength,which may result in high sidelobe levels,grating lobes.Therefore,by using uniform subarray to estimate the direction of arrival(DOA),a virtual contiguous uniform array is constructed by restoring the received signal on the virtual elements,and the degree of freedom of the beamforming is greatly increased.By estimating the signal power,the interference-plus-noise covariance matrix(INCM)of the virtual contiguous array can be reconstructed,and then the weight vector of the beamforming can be obtained.Simulation results demonstrate that compared with the other beamforming methods,the proposed algorithm has smaller mainlobe width,lower sidelobes,faster convergence speed,and better antiinterference capability.