双重优化的宽带聚焦波束形成算法研究

Research on Dual Optimized Broadband Beamforming Algorithm

在相干信号子空间法中确定聚焦矩阵时,对初始方向估计的偏差和聚焦频率选择的偏差都会影响最终的聚焦效果,甚至会使算法失效。针对这个缺陷,提出了一种双重优化的宽带聚焦波束形成算法。该算法利用稳健Capon波束形成算法对聚焦矩阵进行修正,使宽带信号通过修正的聚焦矩阵全部聚焦在最佳聚焦频率上,再对窄带数据利用2阶锥方法实现波束形成。计算机仿真以及湖试实验结果表明,该算法在保证波束恒定的前提下,在各个频率点都具有更低的旁瓣级。

When the focusing matrix is identified in the coherent signal-subspace method, the deviation of the initial direction and the deviation of focusing frequency selection have an effect on the final focusing effect, even making the algorithm fail. A dual optimized broadband beamforming algorithm is presented. The algorithm is to use the robust Capon beamforming algorithm to correct the focusing matrix, the broad- band signals are focused on the best focusing frequency by the corrected focusing matrix, and the narrow- band signals are beamformed by the second-order cone programming algorithm. The computer simulation results and lake experiments show that the proposed algorithm can make the beam constant, and lower the sidelobe level at each frequency point.