Abstract: Secondary Users（SUs） use the Channel Hopping（CH） sequences to sharing dynamic spectrum is one of the solution to the problem in spectrum sharing for distributed Cognitive Radio Networks（CRN）. In this type of spectrum sharing, SUs tune themselves to the idle channels following predetermined CH sequences, and realize rendezvous with each other during this process. According to the characteristics of distributed CRN, this paper proposes a super frame under MAC protocol for rendezvous operation which has the aim of getting better system performance. An intelligent spectrum database is proposed to store the spectrum sensing results and the channel occupancy history. The database is used to support the actions of channel accessing for SUs. Simulation results show that the proposed MAC protocol can get a better comprehensive performanceunder high traffic conditions.

Key words: cognitive radio, distributed network, spectrum sharing, rendezvous, intelligent analysis

摘要： 次用户以跳频序列的方式共享动态的频谱是分布式认知无线电网络频谱共享技术的解决方法之一。在此类方法中，次用户跟随特定的跳频序列接入到它的所有可用信道中，并在此过程中实现与其他次用户的交会。根据分布式认知网络的组网特性，提出了一种针对交会操作的MAC层超帧结构，使得整个认知网络在此结构支撑下可以取得更好的系统性能。根据次用户的频谱感知和使用信道情况的积累与分析，建立次用户的智能频谱库，为次用户的信道接入提供策略支持。仿真结果表明，提出的MAC协议能在高网络负载情况下能获得较好的综合性能。

关键词: 认知无线电, 分布式网络, 频谱共享, 交会, 智能分析