一种适应时变信道的多用户多信道自适应协议

A multi-user multi-channel adaptive protocol for time-varying channels

在认知网络中,具有强时变性的信道状态、用户状态影响着系统性能.为了提高系统吞吐量,实现用户最大通信速率,如何将时变的信道、用户状态和链路自适应调制与编码匹配是一个亟待解决的问题.针对此,提出了一种匹配检验分配协议(matching-check allocation protocol,MAP).该协议联合链路自适应包错误率与通信速率,旨在实现信道状态、用户状态与传输模式匹配的同时最大化系统总通信速率.为了评估频谱分配协议在多用户多信道联合目标优化等复杂网络复杂指标下的性能,利用离散时间排队模型分析非授权用户行为,构建了一种通用的、适用性强的协议评估框架,得到了平均队长、平均吞吐量、平均时延、平均拒绝量等综合性能指标.在该框架下,将MAP与最大速率分配协议、公平随机分配协议进行比较.数据结果表明了MAP优于对比协议,也表明了协议评估框架能够评估不同的频谱分配协议,证明了MAP与协议评估框架的有效性.

In a cognitive radio network,the channel condition state and user state which are both strong time-varying affect the system performance.In order to improve the system throughput and achieve the maximum communication rate of secondary users(SUs),how to match the channel state and user state with adaptive modulation and coding(AMC)scheme is an urgent problem to be solved.This paper proposes a matching-check allocation protocol(MAP)which combines adaptive packet error rate and communication rate to maximize the total throughput of the system while matching the channel state and user state with AMC scheme.In order to evaluate the performance of spectrum allocation protocol under complex network,such as multi-user multi-channel joint objective optimization,this paper using discrete-time queueing model analyses the behavior of SUs to construct a universal and applicable protocol evaluation framework,which obtains performance indexes,such as the average queue length,throughput,delay and rejection.In this framework,MAP protocol is compared with maximum-rate allocation protocol(MRP)and fair-random allocation protocol(FAP).Numerical results show that MAP is superior to MRP and FAP,and the protocol evaluation framework can evaluate different spectrum allocation protocols,which proves the effectiveness of MAP protocol and protocol evaluation framework.