Abstract: A limited-feedback new algorithm with low amount of feedback for LTE systems based on channel information mean is proposed. The frequency response coherence among the subcarriers is exploited to uniformly divide the overall subcarriers of the OFDM systems into several sub-carrier clusters, and the sub-carriers in each cluster are further equally divided into several subgroups except the cluster head. Then the corresponding optimal precoding matrix is searched according to the channel information mean of each subgroup. Numerical simulations show the proposed scheme can not only ensure the system performance, but also significantly reduce the feedback overhead.

Key words: feedback overhead, sub-band clusters, Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing（MIMO-OFDM）

摘要： 研究了LTE系统的一种基于信道信息均值的低反馈量有限反馈新算法。该算法利用子载波之间的频率响应相干性，将OFDM各子载波均匀分割成若个子载波簇，对每个簇内，除去簇头的其余子载波再等分分组，以各分组内子载波的信道信息均值为依据，进行最优预编码矩阵搜索。数值仿真表明，该算法不仅有效地保证了系统系能，而且使反馈开销得到了显著降低。

关键词: 反馈量, 子载波簇, 多输入多输出-正交频分复用（MIMO-OFDM）