【作者】 刘伟东；

【导师】 吕铁军；

【作者基本信息】 北京邮电大学 ， 信号与信息处理， 2010， 硕士

【摘要】 随着无线通信技术的发展,无线频谱的需求在不断的增加,频谱资源变得越来越紧缺。而在现行的无线频谱管理体制下,大量的已分配频谱却经常未被使用。频谱稀缺与频谱的低利用率之间的矛盾越来越突出,为了解决频谱利用率低的问题,感知无线电技术应运而生。它能够自适应的接入空闲信道而不对主用户造成任何干扰,从而最大限度的提高频谱利用率。在新世纪优秀人才计划(项目编号：NCET-06-0091)和国家高新技术863项目(频谱资源共享无线通信系统,项目编号：2009AA011802)的支持下对频谱感知技术进行了研究,本文的结构如下所示：本文首先介绍了本课题的研究背景,然后阐述了感知无线电技术在国内外的研究现状及其关键技术的介绍,指明了本论文的研究方向。然后介绍了现有的感知无线电频谱感知技术。将频谱感知技术主要分为四大类,并对这四类技术的原理和技术背景做了介绍,并得出结论：合作检测已经成为感知无线电频谱感知发展的趋势,本文研究的重点也将围绕合作式频谱检测展开。接下来重点介绍了两种在合作式频谱感知方法中基于不确定性推测的融合策略：证据理论方法和模糊矩阵评价方法。通过对这两种方法的详细介绍以及与传统融合策略的比较,总结了它们的优缺点。紧接着将各个感知用户检测结果的“不确定性”考虑到检测算法中,提出了两种基于模糊积分和最优化理论的频谱感知算法。文中给出了这两种算法的系统模型和算法原理,并且通过仿真分析,比较了所提算法与目前常用的“证据理论”、“与”“或”和“大多数”融合准则的合作式频谱检测方法的检测性能,本文所提的基于模糊积分和最优化理论的频谱感知算法的检测概率、虚警概率和总错误概率性能均优于其他算法,大大提高了整个感知无线电系统的频谱检测的正确性。最后对感知无线电频谱感知技术进行了总结和展望更多还原

【Abstract】 With the development of wireless communication technology, the need for bandwidth is increasing continuously, and the growing need makes wireless spectrum resources more and more scarce. Within the current spectrum regulatory framework, however, a large number of spectrum resources are often idle. The conflicts between spectrum scarcity and spectrum under-utilization become more obvious, and they are caused by the mismatch between static spectrum planning system and dynamic use of spectrum. In order to solve the conflicts between spectrum scarcity and spectrum under-utilization, cognitive radio (CR) technology was recently proposed. It can improve the spectrum utilization by allowing secondary networks (users) to borrow unused radio spectrum from primary licensed networks (users) or to share the spectrum with the primary networks (users).Thanks for New Century Excellent Talents in University (NCET) under Grant No and NCET-06-0091 and the National High-tech R&D Program of China (863 program) under Grant No.2009AA011802, these two programs support my research. The content is organized as follows.This paper introduces the background of the research topic and presents some general information of cognitive radio initially. It also gives out the definition and the function of the CR, as well as the key technologies and the current research situations at domestic and abroad in detail, Through detailed background information, the main research areas of this dissertation is determined. Chapter two describes the existing spectrum sensing cognitive radio technology. Spectrum sensing technology can be divided into four categories, and these four technologies are introduced in detail. According to the introduction, the conclusion can be made that:cooperation detection of the radio spectrum has become trend of cognitive radio development. Chapter three focuses on two of the cooperative spectrum sensing methods based on uncertainty integration strategy:they are the evidence theory and fuzzy matrix evaluation. With a detailed description of these two methods and their comparisons with traditional integration strategies, their advantages and disadvantages are summarized. Through chapter four, uncertainty is taken into account into the detection algorithms by the innovative way. The two spectrum sensing algorithms based on fuzzy integral and optimization theory are introduced in detail. Compared to AND, OR, Majority and evidence theory fusion strategies implementing in cooperative spectrum sensing scheme, the proposed algorithms has better performance. In the end, spectrum sensing in CR are summarized and the prospects for the research are speculated.更多还原