多用户MIMO-OFDM系统中的子信道与功率分配算法研究

The study of sub-channel and power allocation algorithms for multiuser MIMO-OFDM systems

针对多用户MIMO-OFDM系统下行链路,分析了通过遍历搜索来使容量最大化的最优子信道与功率分配算法,在此基础上提出了低复杂度的次优多用户子信道与功率分配算法,即MSPA算法。为了最大限度地保证用户之间的公平性,进一步提出了考虑每个用户速率要求的MSPA-RoU算法。仿真结果表明:本文提出的MSPA算法在复杂度可接受的情况下所获得的容量增益与最优算法十分接近,并且远远大于在MIMO环境下仅对子载波进行分配的算法;MSPA-RoU算法在考虑用户速率要求时仍能获得可观的容量增益。

For multiuser MIMO-OFDM systems downlink, the optimal sub-channel and power allocation algorithm based on the capacity maximum criterion is analyzed, after that we propose a suboptimal multiuser sub-channel and power allocation algorithm with lower complexity, called MSPA algorithm. To guarantee the fairness of different users, a algorithm called MSPA-RoU with consideration of user rate requirements is proposed. Simulation results show that the proposed MSPA algorithm has almost the same capacity performance with the optimal algorithm, and has advantage with the algorithm that only allocated sub-carrier in MIMO environments; MSPA-RoU algorithm also has fairly well capacity performance with consideration of user rate requirements.