认知无线电网络一种自适应切换机制的Markov建模分析

为了提高认知无线电网络(CRN)的利用率和吞吐量性能,提出了一种新的主用户优先的自适应频谱切换机制。强调主用户的优先地位,并考虑主用户到达率对次用户的通信影响和限制次用户对主用户的干扰功率,次用户以此自适应地决定执行主动切换机制或被动切换机制。在此自适应切换机制下建立了主次用户之间的Markov链,求出了相应的稳态概率,由稳态概率和不同状态下的吞吐量推导出系统吞吐量和信道利用率的解析表达式。又对次用户之间的通信建立了一个Markov链,推导出次用户之间传递控制信息的时间。数值结果表明提出的新的自适应切换机制比基于CSMA的接入方法具有更高的系统吞吐量和信道利用率,并且可以求出次用户之间的传递时间。

Markov modeling analysis of adaptive handoff strategy in cognitive radio networks

To improve the channel utilization and throughput performance of CRN,this paper proposed a new adaptive spectrum handoff strategy,which emphasized the priority of primary user,considered the influence of the arrival rate of the primary user(PU)on the communication of the secondary user(SU)and limited the interference power of the secondary user to the primary user,and SUs adapted to a reactive or a proactive handoff strategy accordingly.This adaptive handoff strategy established the Markov chains between primary and secondary users,and gave the steady-state probabilities respectively.From the steady-state probability and throughput under different states,it derived the analytic expressions of system throughput and channel utilization.And it established a Markov chain for the transmission between secondary users,derived the time to transfer control information between secondary users.Numerical results show that the proposed adaptive handoff strategy has higher throughput and channel utilization than the CSMA-based random access approaches,and can be used to derive the time to transfer control information between secondary users.