一种基于矩阵重组的功率倒置改进算法

针对功率倒置（Power Inversion,PI）算法信噪比恶化问题，推导了最小均方误差准则下最优权矢量组成，提出了处理增益更高、工作范围更广的改进算法。算法通过对接收信号协方差矩阵进行特征分解，根据特征值分布特点舍去噪声特征向量，组成新的协方差矩阵，得到具有指向性的最优权值矢量。仿真结果表明，与传统PI算法相比，改进算法在期望方向形成自适应波束，获得的信干噪比增益和信噪比增益高出约9.6 dB，较好地改善了信噪比恶化问题。

An Improved Power Inversion Algorithm Based on Matrix Recombination

To solve the problem of signal-to-noise ratio(SNR) deterioration of power inversion(PI) algorithm,this paper analyzes the composition of the optimal weight vector with the minimum mean square error(MMSE) criterion and proposes an improved algorithm with higher processing gain and wider working range.By means of eigendecomposition of the received signal covariance matrix,the improved algorithm cuts out the noise eigenvectors according to the feature of eigenvalue distribution and gets a new covariance matrix and a new weight vector with directivity.Simulation results show that,compared with the traditional PI algorithm,the improved algorithm forms an adaptive beam in desired direction,and both the SNR gain and signal-to-interference plus noise ratio(SINR) gain obtained are about 9.6 dB higher.The improved algorithm has a better performance in solving the problem of SNR deterioration.