多用户MIMO系统下的闭环调度算法及频谱性能分析

摘要

A closed-loop scheduling algorithm was proposed for multi-user Multi-Input Multi-Output (MIMO) system to improve wireless spectral performance. Using greedy scheduling technology from multi-user diversity, the algorithm combined the adaptive modulation in the physical layer with automatic repetitive request in the data link layer, and the system's spectral efficiency was enhanced under the interaction of the multi-antenna diversity and multi-user diversity. Considering the practical case of delayed feedback environment, the closed-form expressions of system spectral efficiency under delayed channel were derived. And the experimental results show that this algorithm can hardly be influenced by delay time, which is more applicable to multi-user MIMO system.%为提高无线频谱资源的利用率,提出一种适应于多用户多输入多输出(MIMO)系统的闭环调度算法.该算法结合多用户的贪婪调度技术、物理层的自适应调制与链路层的自动重传技术,在多天线分集与多用户分集的共同作用下,系统频谱性能显著增强.考虑反馈信道存在延时的实际情况,推导了系统在延时信道条件下的频谱效率表达式.仿真结果证实,该算法在多用户系统中受延时影响较小,更适合应用于多用户MIMO系统.