基于授权用户状态迁移统计特性的频谱感知算法  

Spectrum sensing in Cognitive Radio by exploiting working states characteristics of primary users

作　　者：李斌[1] 周正[1] 邹卫霞[1] 

机构地区：[1]北京邮电大学无线网络实验室泛网无线通信教育部重点实验室

出　　处：《现代电信科技》2010年第9期30-36,共7页Modern Science & Technology of Telecommunications

基　　金：国家重大科技发展专项(2009ZX03006-006;2009ZX03006-009);北京邮电大学优秀博士生创新基金资助项目(CX201013)

摘　　要：通过动态监测各个频段使用状况并机会性地接入空闲频谱,认知无线电技术可显著提高已分配频段的频谱利用效率,继而有效地缓解频谱资源日趋枯竭的现状。文章首先采用一类具有记忆特性的状态迁移模型来刻画授权用户行为;综合考虑漏检概率与虚警概率的影响,建立了频谱检测的代价函数;在此基础上,采用最大后验概率准则实现检测算法,并对理论算法进行修正,使其满足实际场景下低复杂度、低检测时延要求。借助于有限状态机模型所隐含的编码增益,该算法能显著提高检测性能,数值仿真也进一步验证了算法有效性。Cognitive radios （CRs） can dramatically improve spectrum utilization and hence resolving the spectrum scarcity, by monitoring the dynamic usage of licensed band aod further taking advantage of spectrums opportunities. In this paper, we suggest a general state transition model with memory to depict the states evolution process of primary users （PU）. Spectrum sensing is then formulated as the detection of a corresponding coded sequence, The maximum posterior probability （MAP） criterion is employed to perform optimum spectrum sensing, in the sensing that minimizing the detection errors. Furthermore, based on the states transition model of PU, it is modified to best serve CR applications. By fully exploring the equivalent potential coding gain, our sensing algorithm can improve the detection probability in combination with other sensing methods. The simulation results also validate the effectiveness of our method.

关 键 词：认知无线电 频谱监测 状态迁移 最大后验概率 

分 类 号：TN92[电子电信—通信与信息系统]