一种大规模MIMO系统的低复杂度预编码算法

A Low Complexity Precoding Algorithm for Large-scale MIMO System

在大规模多输入多输出系统中,基站侧天线数目和用户数目的增加导致信道矩阵的维度也增加,从而使预编码矩阵的计算复杂度增大。为此,将截断多项式展开理论与最小均方误差(MMSE)预编码算法相结合,提出一种低复杂度的预编码算法。将矩阵多项式的前J项和近似为矩阵的逆矩阵,在MMSE预编码的基础上推导该算法的预编码矩阵,并求解发射功率有限时最佳阶数的表达式。仿真结果表明,在与MMSE预编码算法频谱效率相近的情况下,该算法可有效降低预编码的计算复杂度。

In large-scale Multiple-Input Mutiple-Output(MIMO)system,the increase in the number of antennas and users on the base station side leads to an increase in the dimension of the channel matrix,which increases the computational complexity of the precoding matrix.To solve this problem,a low complexity precoding algorithm is proposed by combining the Truncated Polynomial Expansion(TPE)theory with the Minimum Mean Square Error(MMSE)precoding algorithm.The sum of the J terms in front of the matrix polynomial is approximated as the inverse of the matrix,based on the MMSE precoding,the precoding matrix of the proposed algorithm is deduced,and the expression of the optimal order is solved when the transmitting power is limited.Simulation results show that the proposed algorithm can effectively reduce the computational complexity of precoding when the spectral efficiency is similar to that of MMSE precoding algorithm.