改进的稳健Capon波束形成算法性能分析

Performance Analysis of Improved Robust Capon Beamforming Algorithm

常规Capon波束形成算法能够使波束在期望信号方向形成高增益，在干扰方向形成零陷，针对该算法在期望信号导向矢量失配的情况下，出现性能下降的问题，研究了期望信号导向矢量在不确定集约束下的求解。通过分析稳健Capon波束形成算法的特点，推导出了期望信号导向矢量在球形不确定集约束下的权矢量近似闭式解，并采用图像法，找到给定条件下的最优约束参数。在指向误差和相位误差存在情况下，对算法进行了仿真分析，仿真结果验证了算法在误差存在情况下的稳健性。

High gain can be formed in the direction of signal of interest, and the nulling can form in the direction of interference by using standard Capon beamforming algorithm. For the performance degradation of the algorithm in the presence of steering vector mismatch of the signal of interest, the problem of solution under the steering vector uncertainty set is investigated. By analyzing characteristics of robust Capon beamforming algorithm, the approximate closed-form solution of the weight vector is deduced in case that the steering vector of the signal of interest is in spherical uncertainty set. The image method is used to find the optimal parame- ters for a given constraint conditions. In the presence of pointing error and phase error, the algorithm is simulated and analyzed, and the simulation results verify the robustness of the algorithm in the presence of error.