基于特征投影矩阵的自适应方向图改善方法

在主瓣干扰背景下，采用特征投影矩阵算法，预处理后自适应方向图将出现主波束偏移，针对传统修正方法中对角加载技术的系数固定且难以确定的问题，基于HKB算法提出了一种改进的加载系数选取方法，根据接收数据能够自适应确定对角加载量。该方法在进行脊回归估计时，通过将剩余矢量的最小方差代价函数的最小二乘估计替换成误差绝对值函数进行分析计算，从而获得新的对角加载系数，同时对自适应抗干扰总效果方向图进行了分析研究，对于旁瓣性能出现的明显恶化，结合所提方法对总效果方向图进行了改善研究。仿真结果表明了所提方法既能有效解决预处理方向图主波束指向偏移问题，同时也改善了总效果方向图的旁瓣性能。

Research on Improvement of Adaptive Pattern Based on Eigen-Projection Matrix

In the presence of main-lobe interference, the main-lobe offset comes out on the adaptive pattern by eigen-projection matrix preprocessing. Aimed at the problem that the fixation of coefficient is difficult to determine in the traditional main-lobe shape-preserving method of diagonal loading technique, an improved ridge regression estimation based on HKB algorithm is proposed. The load can be determined adaptively according to the data received. The new diagonal loading coefficient is obtained by replacing the minimum variance cost function of the residual vector with the error absolute value function when performing the ridge regression estimation. At the same time, the improvement of the proposed method for the adaptive anti interference total effect pattern is studied. For the obvious deterioration of the side lobe performance, the improvement of the total effect pattern is studied in combination with the proposed method. The simulation results demonstrate that the proposed method is correct and effective, and not only can effectively solve the main lobe offset problem of the pre-processed pattern, but also improve the side-lobe performance of the total effect pattern.