为有效提升多输入多输出系统的频谱效率，降低算法复杂度，文章提出了一种基于迭代思想的矩阵分解算法。首先初始化模拟预编码矩阵并获取最优预编码矩阵；然后通过模拟预编码矩阵与最优预编码矩阵来获取数字预编码矩阵，通过提取数字预编码矩阵中的相位信息更新模拟预编码矩阵，利用已更新的模拟矩阵来更新数字矩阵；最后通过不断交替迭代直到收敛。仿真结果表明，所提算法具有较低的复杂度且更接近纯数字预编码性能。

In order to effectively improve the spectrum efficiency of the Multiple-Input Multiple-Output (MIMO)system and reduce the complexity of the algorithm, this paper proposes a matrix decomposition algorithm based on iterative method. First, the analog precoding matrix is initialized and the optimal precoding matrix is obtained. Then the digital precoding matrix is obtained by simulating the precoding matrix and the optimal precoding matrix, and the analog precoding matrix is updated by extracting the phase information in the digital precoding matrix. The updated simulation matrix updates the digital matrix and finally iterates through alternating iterations until convergence. The simulation results show that it has lower complexity and better performance, which is closer to the pure digital precoding performance.