毕业设计英文翻译——认知无线电频谱感知算法仿真.doc

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1、*仅供参考上海电力学院毕业设计（英文翻译）课题名称认知无线电频谱感知算法仿真院（系）专业班级学生学号ImplementationIssuesinSpectrumSensingforCognitiveRadios认知无线电频谱感知的实现问题Abstract:Therearenewsystemimplementationchallengesinvolvedinthedesignofcognitiveradios,whichhaveboththeabilitytosensethespectralenvironme

2、ntandtheflexibilitytoadapttransmissionparameterstomaximizesystemcapacitywhileco-existingwithlegacywirelessnetworks.Thecriticaldesignproblemistheneedtoprocessmulti-gigahertzwidebandwidthandreliablydetectpresenceofprimaryusers.Thisplacessevererequirementsons

3、ensitivity,linearity,anddynamicrangeofthecircuitryintheRFfront-end.Toimproveradiosensitivityofthesensingfunctionthroughprocessinggainweinvestigatedthreedigitalsignalprocessingtechniques:matchedfiltering,energydetection,andcyclostationaryfeaturedetection.Ou

4、ranalysisshowsthatcyclostationaryfeaturedetectionhasadvantagesduetoitsabilitytodifferentiatemodulatedsignals,interferenceandnoiseinlowsignaltonoiseratios.Inaddition,tofurtherimprovethesensingreliability,theadvantageofaMACprotocolthatexploitscooperationamon

5、gmanycognitiveusersisinvestigated.摘要：出现了一些新系统的实施挑战，其涉及认知无线电——具有感知频谱环境下的传输参数既适应能力和灵活性，以最大限度地提高系统容量，同时并存于传统无线网络。关键设计问题是需要处理多千兆赫宽的带宽，可靠地检测主用户的存在。这对灵敏度，线性度和在RF前端电路的动态范围有严格要求。为了通过处理增益而提高无线电灵敏度，我们调查了三种数字信号处理技术的感测功能：匹配滤波，能量检测和循环平稳特征检测。我们的分析表明：由于能够区分调制信号，干扰和噪声在低信噪

6、比，循环平稳特征检测更有优势。此外，为了进一步提高检测的可靠性，MAC协议，它利用在许多认知用户合作的优势已经在这一块研究很久了。I.INTRODUCTION一、介绍1.Itiscommonlybelievedthatthereisaspectrumscarcityatfrequenciesthatcanbeeconomicallyusedforwirelesscommunications.Thisconcernhasarisenfromtheintensecompetitionforuseofspectr

7、aatfrequenciesbelow3GHz.TheFederalCommunicationsCommission’s(FCC)frequencyallocationchartindicatesoverlappingallocationsoverallofthefrequencybands,whichreinforcesthescarcitymindset.Ontheotherhand,actualmeasurementstakenindowntownBerkeleyarebelievedtobetypi

8、calandindicatelowutilization,especiallyinthe3-6MHzbands.Figure1showsthepowerspectraldensity(PSD)ofthereceived6GHzwidesignalcollectedforaspanof50µssampledat20GS/s[12].ThisviewissupportedbyrecentstudiesoftheFCC