MIMO-OFDM系统中一种低开销有限反馈新方法

New limited feedback method with lower overhead in MIMO-OFDM system

以LTE-Advanced为背景,针对多输入多输出—正交频分复用(MIMO-OFDM)系统中的关键技术——基于码本的有限反馈预编码进行了研究,提出了一种基于递归算法的有限反馈新方法。利用各子载波间的频域相关性,以前一个子载波所选码字为基础,通过内积运算排序的方法来确定当前子载波的码字集合,然后对与该新码字集合相对应的码字索引进行可变长编码,以用于系统反馈。仿真结果表明:在递归反馈算法的基础上利用可变长编码能有效降低LTE-Advanced系统的反馈开销。

This paper investigated the limited feedback technology based on the Multiple Input Multiple Output Orthogonal Frequency Division Multiple（MIMO-OFDM） system in LTE-Advanced applications.A new limited feedback method based on recursive feedback was proposed.The method utilized the correlation between the subcarrier channels.The codewords for the current subcarrier could be determined by ordering the result of the inner product with respect to the codewords of the previous subcarrier.Then the variable length encoding method was used to code the index of the new codewords.The experimental results show that the recursive feedback algorithm based on variable length coding can reduce the feedback bits effectively in LTE-Advanced systems.