自适应对角线加载的波束形成算法

Adaptive Diagonal Loading Beamforming Algorithm

采样协方差矩阵求逆(SMI)的波束形成方法在少快拍数、高信噪比情况下波束形成性能下降。对角线加载技术能减弱了小特征值对应的噪声波束的影响,改善了方向图畸变,但是加载量的确定一直以来是一个比较困难的问题。文中提出了一种自适应对角线加载波束形成算法,根据阵列接收信号协方差矩阵的特征结构,自适应地加载对角线,进而提高波束形成的鲁棒性。仿真结果表明:该算法在高、中、低的信噪比下都具有较好的波束形成性能,且在少快拍数情况下仍具有较好的波束形成性能,是一种鲁棒的且性能优越的波束形成算法,而且该算法容易实现。

Sampling matrix inversion beamforming technique （SMI） has the worse performance in the small snapshot number and high signal-noise-ratio. Diagonal loading technique can suppress noise beamforming for the small eigen value, and improve the beamforming aberration. But loading value is hard to solve. An adaptive diagonal loading beamforming algorithm is proposed in this paper. The algorithm loads adaptively diagonal matrix to enhance the algorithm robostness, according to the eigen structure of the received signal covariance matrix. Simulation results reveal that the algorithm has the better beamforming performance than conventional adaptive beamforming algorithm in the lower, middle and high signal-noise-ratio （SNR）, and it has the better performance in the small snapshot number. So it has robust characteristic and the better performance. Finally the algorithm is no more complex and can be implemented easily, and it can be used widely.