迭代寻优的稳健波束形成

Robust adaptive beamforming based on iterative optimization

针对导向矢量失配程度较大时,常见稳健波束形成算法性能下降问题,提出了一种迭代搜索最优导向矢量的稳健波束形成算法。首先利用修正后的导向矢量构造使波束输出功率最大的目标函数,分别从干扰抑制和噪声抑制2个方面推导了新导向矢量应满足的约束条件。给出了利用矩阵滤波思想构造约束条件的方法并分析其合理性。针对优化问题难以求解的问题,提出了一种迭代寻优的搜索方法,将每次迭代转化为求解一次二阶锥规划问题。仿真分析表明,相比于常见稳健波束形成算法,该算法有更高的抗导向矢量失配的稳健性,且需要的先验信息更容易获取。

The performance of common robust adaptive beamforming degrades with the increasing degree of the signal steering vector error. To solve this problem, a robust adaptive beamforming algorithm was proposed on the basis of searching optimal signal steering vectors with an iterative strategy. The objective function that maximizes the beamformer output power was constructed by a corrected steering vector, while the constraint was deduced from both respects of interference suppression and noise suppression. The approach of structuring constraint by using a matrix filter was given and the rationality was explicated. Considering the difficulty in solving the optimization problem, an iterative optimization method was proposed, and the method solved a second-order program problem at each iteration. The simulation results show that, compared with common methods, this proposed method achieves higher signal-to-interference-plus-noise ratios （ SINR） in the case of a steering vector mismatch. Moreover, the prior information of this proposed method is easier to extract.