摘要
比例公平调度算法在系统吞吐量和公平性之间能取得较好的权衡,它在无线网络资源分配中已经成为一个突出的候选方案。但比例公平调度算法本身存在一些缺陷,如无法反映用户的信道状态,没有考虑不同业务的服务质量等。考虑用户的信道状态,针对比例调度算法在分配资源时会抑制不良信道用户的吞吐量,进而影响整个系统的吞吐量的问题,提出了一种改进的比例公平调度算法,以提高IEEE802.16m下行OFDMA系统的吞吐量。该算法根据用户的信道速率将用户分成多个组。先计算每组的调度优先级,然后选择调度优先级最高的组进行调度,最后在选择的组中根据轮询调度算法对用户进行资源分配。仿真结果表明,改进的比例公平调度算法在吞吐量、公平性、时延、丢包率等方面优于传统的比例调度算法。
Proportional fair scheduling algorithm can obtain a good trade, off between system throughput and fairness. It has become an out- standing candidate scheme in wireless networks resource allocation. However,there are some defects in proportional fair scheduling algo- rithm. For example,it doesn＇ t reflect the users＇ channel state and consider the quality of different service. When it comes to the users＇ channel state,since the proportional scheduling algorithm will inhibit the throughput of the poor channel users ,and then affect the overall system throughput. In view of this problem, an improvec proportional fairness scheduling algorithm is proposed, which will improve the throughput of IEEE802.16m downlink OFDMA system. According to the users＇ channel rate ,the scheduling algorithm classifies users in- to several groups. Firstly, the scheduling priority of each group will be calculated. And then the group with the highest scheduling priority will be scheduled. Finally ,according to the round-robin scheduling algorithm,resources will be allocated to users in the selected group. The simulation shows that the improved proportional faicness scheduling algorithm is better than the original in terms of throughput, fair- ness, delay and packet loss rate.
出处
《计算机技术与发展》
2016年第9期158-162,共5页
Computer Technology and Development
基金
国家自然科学基金资助项目(61401374)
