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本科毕业设计-认知无线电频谱检测技术的研究与仿真，共40页，21708字符数，附任务书、开题报告、答辩PPT、外文翻译
中英文翻译 Spectrum Efficiency Improvement Based on the Cognitive（基于认知无线电协议频谱效率的改善）

 本课题就是对常用的认知无线电频谱检测技术，即能量检测法、匹配滤波器检测法以及循环特征检测法，进行研究，在此基础上，利用MATLAB软件对各种检测法的结果进行仿真，比较其性能。
摘要 无限业务的持续增长带来频谱需求的不断增加，无限通信的发展面临着前所未有的挑战。无线电频谱资源一般是由政府统一授权分配使用，这种固定分配频谱的管理方式常常会出现频谱资源分配不均，甚至浪费的情形，这与日益严重的频谱短缺问题相互矛盾。认知无线电技术作为一种智能频谱共享技术有效的缓解了这一矛盾。它通过感知时域、频域、和空域等频谱环境，自动搜寻已授权频段的空闲频谱并合理利用，达到提高现有频谱利用率的目的。频谱感知技术是决定认知无线电能否时间的关键技术之一。
本文首先介绍了认知无线电的基本概念，对认知无线电在WRAN系统、UWB系统及WLAN几桶等领域的应用分别进行了讨论。再次基础上，针对实现认知无线电的关键技术从理论上进行了探索，分析了影响认知网络正常工作的相关因素及认知网络对授权用户正常工作所形成的干扰。从理论上推到了在实现认知无线电系统所必须面对的弱信号低噪声比恶略环境下，信号检测的相关方法和技术，并进行了数字滤波器的算法分析，之处了窗函数的选择原则。接着详细讨论了频谱检测技术中基于发射机检测的三种方法：匹配滤波器检测法、能量检测法和循环特征检测法。为了检验其正确性，借助MATLAB工具，在MATLAB平台下对能量检测和循环特征检测法进行了建模仿真，比较分析了这两种方法的检测性能。研究结果表明：在低信噪比的情况下，能量检测法检测正确率较低，检测性能远不如循环特征检测，并提出了对算法的窗函数的改进可以提升循环检测算法的性能。

关键词 认知无线电 频谱感知 弱信号检测 数字滤波

The research and simulation of spectrum sensing base on the cognitive
radio management
Abstract:The development of the wireless business results in increasing needs of the frequency.Wireless communication is facing a challenge.Radio resource is distributed by the government,which generally rises inequality and waste of Radio resource.So,there is a contradiction between the waste and the shortage of Radio resource.The cognitive radio,a technology of intelligent spectrum sharing,effectively bridges the contradiction.Based on the perception of time domain,frequency domain and airspace,automatic discovery and reasonably use of free spectrum among distributed spectrum,the cognitive radio improves the utization ratio in the existing frequency.Spectrum sensing is one of the sky technologies in the cognitive radio.
Based on the introduction of Cognitive Radio(CR) and the discussion of applications of CR in WRAN,UWB and WLAN,the key technologies of achieving CR were researched in theory and the factors controlling cognitive network and the interferences raised by cognitive nerwork in normal working of authorized user were analyzed.The related method and technology of signal detection was theoretically derived in the severe environment of weak signal and low signal to noise ratio that is must facting to achieve CR.With the algorithm analysis of digital filter,the selection principle of windows function was proposed.Three spectrum detection methods,namely matching filter detection way,energy ditection way and cycle property detdction way,were investigation in great detail.For testing and verifying the correction of above results,the detailed modeling and simulation of energy detection and cycle property detection were completed with MATLAB and the performances of that two detections were also compared.The results show that the energy detection way,in the low SNR,is low and the property of that is very poorer than the cycle property detdction.And this paper suggested that improverment of algorithm of window function can promote the performance of cycle algorithm.

Keywords: Cognitive Radio Specrtum Sensing Weak Signal Detection Digital Filte

目 录

摘要 I
Abstract: II
第一章 引言 1
1.1认知无线电的研究意义及背景 1
1.2 认知无线电技术的国内外发展现状 1
1.3认知无限电的关键技术 3
1.3.1频谱感知技术 3
1.3.2频谱分配技术 4
1.3.3功率控制技术 5
1.4 全文的主要研究内容 6
第二章 认知无线电频谱感知技术的算法研究 7
2.1 信号检测理论 7
2.2 微弱信号检测的原理 7
2.3 微弱信号检测的基本方法 8
2.3.1窄带滤波法 8
2.3.2同步累计法 9
2.3.3相关检测法 10
2.3.4锁定接收法 11
第三章 频谱感知技术的方法研究 14
3.1 认知无线电频谱感知技术 14
3.2 认知网络的频谱检测模型 14
3.3 发射机检测 15
3.4协作检测 21
第四章 设计的仿真与性能的分析 23
4.1 能量检测算法仿真 23
4.2 循环平稳特性检测算法仿真 24
4.3 性能分析与比较 25
4.4 协作检测算法仿真 26
结 论 28
致 谢 29
参考文献 30
附 录 32