相关信道下基于多用户STBC-OFDM系统的子载波分配

摘要

针对多用户空时分组码-正交频分复用(STBC-OFDM)下行链路系统,以总发射功率最小化为优化目标,给出一种在空间相关瑞利衰落信道下基于部分信道状态信息(CSI)的自适应子载波分配算法.该算法利用克罗内克(Kronecker)模型表示每个子载波对应的空间相关多输入多输出(MIMO)瑞利衰落信道,并通过动态发射端的信道状态信息(CSIT)模型来描述CSI的反馈过程,从而应用STBC的基本原理推导出相应的子载波分配原则.实验结果表明,该算法不仅能有效地反映天线相关矩阵中相关系数以及延时反馈参数对系统性能的影响,而且与未利用CSIT模型的子载波分配相比具有较好的性能.%With the optimization goal of minimizing the total transmit power, an adaptive subcarrier allocation algorithm based on partial Channel State Information (CSI) under the condition of spatially correlated Rayleigh fading channels was proposed for multiuser STBC-OFDM downlink systems.In the course of algorithm implementation, the Kronecker model was used to express spatially correlated Multiple-Input Multiple-Out-put (MIMO) rayleigh fading channels of each subcarrier, and the dynamic CSIT ( CSI at the Transmit) model was utilized to describe the process of CSI feedback; thus, the corresponding subcarrier allocation criteria could be deduced by means of the basic principles of Space-Time Block Cede (STBC).The experimental results show that the proposed algorithm not only can effectively reflect system performance effects of the correlation coefficients of antenna correlation matrix and the parameters of delayed feedback, but also has good performance in contrast to subcarrier allocation without CSIT.