波达方向误差对对角加载波束形成的影响研究

文章回顾了对角加载波束形成理论的发展，列举了几种较常使用的求取对角加载因子的方法。通过多个仿真实例，着重分析了Xavier提出的基于无限随机矩阵理论的对角加载因子的方法．指出了其局限性一在期望信号的方向向量存在误差的时候，该方法产生自消现象，从而波束形成器的性能急剧下降。本文结合特征空间波束形成，根据期望信号的实际方向向量正交于噪声子空间，提出一种改进方法一先对期望信号的方向进行校正，再求取对角加载因子，从而加强了Xavier的方法对波达方向失配的稳健性。仿真实例验证了在信噪比不大的时候这个方法的有效性。

A study of the effects of direction-of-arrival estimate errors on diagonal loading beamforming

The development of diagonal loading beamforining technique is reviewed and some methods of computing diagonal loading factor are presented. Then, by simulation examples, the infinite-random-matrixbased beamforining presented by Xavier is analyzed. The result shows that the sell-hulling phenomenon happens in the scenario with steering vector errors to degrade the performance severely. Due to the orthogonality between the steering vector of the signal of interest （SOI） and the noise space, an improved method elicited by the eigenspace-based beamforining （ESB） is proposed, in which the direction of SOI is first calibrated. This method can improve the robustness of the beamformer in the case of Direction- of-Arrival （DOA） uncertainties. The result of the numerical simulation shows the effectiveness of this method when the SNR is not great.