基于认知无线电网络的动态频谱分配

Dynamic Spectrum Allocation Based on Cognitive Radio Network

针对无线通信网络中频谱日益紧缺的问题,对基于认知无线电网络的动态频谱分配技术进行研究,提出一种保护信道和排队相结合的动态信道分配方案。该方案在不影响主用户业务的情况下,为因主用户到达而切换的次用户预留保护信道,对新到达的次用户采用排队策略。如果系统中主用户或者次用户因服务完毕而离开时,队列中的次用户则可按一定的次序使用空闲可用的子信道。仿真结果表明,与仅预留保护信道和仅使用队列缓冲器的方案相比,该方案能有效降低系统的总体失败率,提高分配性能,且对次用户的平均吞吐量和平均延迟影响较小。

Aiming at the problem of the growing contradiction between demand and supply of spectrum in wireless communications, this paper does further research on dynamic spectrum assignment based on Cognitive Radio Network（CRN）, and presents a dynamic channel allocation strategy combining guard channel with queuing. In the case without affecting primary user＇s services, because of arrival of primary user, the scheme provides reserved channels for handover secondary users, and queuing stx：ategy is adopted for new arrival secondary users. When there is departure of ongoing primary user or secondary user, secondary users in queue can use idle available sub-channels according to priority-ranked. Compared with only reserving guard channel and only using queue buffer, the strategy has a small impact on secondary user average throughout and average delaying, and effectively reduces overall system failure rate and improves the performance of the system.