OFDMA系统实时业务分组调度算法

在移动通信系统中，常见的调度算法在处理实时业务时一般为信道状况好的用户分配过多的资源，而信道状况差的用户获得的调度机会相对较少。为保证实时业务的延迟要求，并兼顾不同用户间的公平性，基于正交频分多址接入系统，提出一种实时业务分组调度算法。在调度过程中，采用丢弃过期数据包的策略节省了系统资源。对信道状况好的用户采用较大的调度间隔，并采用高阶的调制编码方案将累积的数据包在一个调度间隔内发送，从而给予信道状况差的用户更多的调度机会。仿真结果证明，提出的算法能较好的满足实时业务的延迟要求，相对于改进的最大权重延迟优先算法和正比公平算法提高了用户间的公平性。

A Packet Scheduling Algorithm for Real-time Traffics in OFDMA Systems

In mobile communication systems, users in good channel state were allocated excessive resources by most of scheduling algorithms when dealing with real-time traffics, while users in bad channel state got relatively few scheduling chances. In order to guarantee the delay requirements of real-time traffics and achieve fairness among different users, a packet scheduling algorithm for real-time traffics was proposed in orthogonal frequency division multiple access (OFDMA) systems. In scheduling processes, the expired data packet discarding strategy was adopted to save system resources. Users in good channel state were scheduled in larger intervals, and cumulative packets were sent in one scheduling interval using high order modulation and coding schemes (MCS). Thus users in bad channel state were given more chances to be scheduled. Simulation results showed that the proposed algorithm could meet delay requirements for real-time traffics, and had a better performance in enhancing fairness among users than modified-largest weighted delay first (M-LWDF) and proportional fair (PF) algorithms.