自适应对角加载在波束形成中的仿真研究

Research on simulation of adaptive diagonal loading method in beamforming

当阵列误差存在时,Capon波束形成算法性能会急剧下降,特别是阵列输出信干噪比(signal to interfer-ence plus noise ratio,SINR)。对角加载可以减弱小特征值对应的噪声波束的影响,能有效改善阵列性能及方向图畸变,但加载值的确定是一个较为困难的问题。该算法根据加载值和采样协方差矩阵间的关系确定加载值,能自适应地根据采样数据确定加载值,在小快拍数和阵列误差存在情况下仍具有良好的鲁棒性,明显改善了阵列性能并减小了方向图畸变,且使零陷准确对准干扰方向。计算机仿真结果证实了此算法的鲁棒性。

When array error exists,the performance of Capon beamforming algorithm would be decreased sharply,especially the performance of the signal to interference and noise ratio（SINR） of the array output.Diagonal loading technique could suppress noise beamforming for the small eigen value,and improved the array performance and pattern aberration effectively,but loading value was hard to confirm.This paper discussed a diagonal loading method based on the relationship between loading value and sample covariance matrix to confirm the loading value,the method could determine the loading value adaptively according to sample data,provided an improved robustness when snapshot was small and array error exists,improved the array performance and reduced pattern aberration and could place the null in the direction of the interference accurately.The result of simulation demonstrates that this method is computationally robustness.