复杂干扰场景下的稳健自适应波束形成

Robust adaptive beamforming in complex interference scenarios

针对复杂电磁环境中最小方差无畸变响应及干扰加噪声协方差矩阵重构波束形成器输出信干噪比下降的问题,本文基于均匀圆阵(uniform circular array,UCA)提出了一种适用于该场景的稳健自适应波束形成算法。所提算法利用稀疏重构技术得到的谱函数构造和改进干扰抑制矩阵,使其在干扰方位产生宽零陷,提高了算法的稳定性。考虑到UCA存在副瓣电平高及空间非均匀采样问题,利用二阶约束优化准则抑制UCA副瓣,使得所提算法在抑制干扰的同时具有较低的波束副瓣。当UCA半径选择合适时,所提算法的性能与最优波束形成器接近,仿真验证了所提算法的有效性。

In a complex electromagnetic environment,the output signal to interference plus noise ratio of the minimum variance distortionless response beamformer and the interference-plus-noise covariance matrix reconstruction beamformer decrease a lot.To solve this problem,a robust adaptive beamforming algorithm based on the uniform circular array(UCA)is proposed.The proposed algorithm constructs and improves the interference suppression matrix based on the spectral function obtained by the sparse reconstruction technique to produce wide null at the interference direction,which effectively improves the stability of the algorithm.Considering the high sidelobes level and spatial non-uniform sampling in UCA,the second-order constrained optimization criterion is adopted to suppress the UCA sidelobes,so that the proposed algorithm has low sidelobes while effectively suppressing interferences.When the radius of the UCA is selected appropriately,the performance of the proposed algorithm is comparable to that of the optimal beamformer.The effectiveness of the proposed algorithm is verified through simulations.