摘要： 在长期演进系统下行链路闭环传输模式中，当子载波数较大时，会造成计算量和反馈量过大。为解决该问题，提出一种基于平均互信息的预编码矩阵选择方法。将K个子载波划分成D个子载波组，对每一个子载波组的信道矩阵进行算术平均，利用信道均值选择一个预编码矩阵，使K个子载波上的和速率最大。仿真结果表明，该方法与已有的预编码矩阵选择方法相比，在误块性能和容量性能基本不变的前提下，计算复杂度明显降低。

关键词: 预编码, 预编码矩阵索引, 子载波, 反馈, 平均互信息, 误块率

Abstract: Considering the closed-loop transmission mode of the Long Term Evolution(LTE) system download link, this paper focuses on the problem that the calculations and feedback grow much more as the number of sub-carriers grows, and gives a new method to select the precoding matrix based on mean mutual information. By dividing the K sub-carriers into D groups and utilizing the mean value of the channel matrix in the same group, it selects a precoding matrix to maximize the sum-rate on the all K sub-carriers. Simulation results show that the complexity of the proposed method is reduced distinctly in comparison with that of the existing methods, meanwhile the Block Error Rate(BLER) and the system capacity performance keep almost the same.

Key words: precoding, Precoding Matrix Index(PMI), sub-carrier, feedback, mean mutual information, Block Error Rate(BLER)

中图分类号: 

• TN929.5