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ID:4343598
大小:960.50 KB
页数:45页
时间:2017-11-30
《认知无线电频谱接入方案的研究毕业论文》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、认知无线电中频谱接入方案的研究【摘要】随着无线通信领域中的各种语音、图像、视频等数字化业务大量增长,导致有限的频谱资源变得日益紧张,成为制约无线通信发展的主要因素。经过FCC研究发现,已经授权给现有无线电业务的频谱在时间和空间上存在不同程度的闲置,即存在频谱空洞,造成了频谱资源的严重浪费。为改变这种局面,人们提出了认知无线电技术。它能够检测频谱空洞,在不对授权用户造成干扰的前提下进行频谱接入,实现频谱共享,从而提高频谱利用率。本文首先介绍了课题研究背景,然后详细论述了认知无线电技术和机会频谱接入技术的定义、关键技术、
2、应用场景和国内外研究现状,并阐述了认知无线电网络的体系架构。接着研究了基于POMDP(部分可观测马尔科夫决策过程)的机会频谱接入算法。并介绍了POMDP算法的三种接入方式以及对各种算法进行仿真,比较各算法的性能。关键词:认知无线电机会频谱接入部分可观测马尔科夫决策过程算法IITheResearchoftheSpectrumAccessinCognitiveRadio【Abstract】Withtheincreasingtrafficofspeech,imageandvideobymeansofwirelesscomm
3、unications,thewirelessspectrumresourceisbecomingincreasinglyscarceanditmayhamperthedevelopmentofwirelesscommunicationsinthefuture.However,FCC(FederalCommunicationsCommission)findsoutthatmanyspectrumbandsallocatedtoexistingwirelesssystemsareshowingdifferentdegre
4、eofidleintermsoftimeandspacefield.Therefore,researchersputforwardcognitiveradiotechnology,whichisabletoeffectivelychangethecurrentspectrumshortagesituation.Itsensesthespectrumholesandaccessesthechannelswithoutcausinginterferencetothelicensedusers.Inthisway,weca
5、nrealizespectrumsharingandimprovethespectrumutilizationefficiency.Thisthesisfirstlyintroducesthestudybackground.Inaddition,weparticularlyexplainthedefinitions,characters,keytechniques,applicationsandstatusquoofcognitiveradioandopportunisticspectrumaccess(OSA)te
6、chnologies.Inaddition,wepresentthestructureofcognitiveradionetworks.Thenthepapermainlyresearchesopportunisticspectrumaccess(OSA)algorithmbasedonPartiallyObservableMarkovDecisionProcess(POMDP),andthenintroducestheiraccessmethodsofPOMDPalgorithmaswellastheirsimul
7、ation.ComparingtheperformanceofthealgorithmKeywords:CognitiveRadio,OpportunisticSpectrumAccess,POMDP,AlgorithmIII名词解释CRCognitiveRadio认知无线电FCCFederalCommunicationsCommission美国联邦通信委员会OSAopportunisticspectrumaccess机会频谱接入ISMIndustrial,Scientific,andMedical医用DFSDyna
8、micFrequencySelection动态频率选择TPCTransmitPowerControl发送功率控制HSDPAHighSpeedDownlinkPacketAccess高速下行分组接入SDRSoftwareDefinedRadio软件定义无线电RKRLRadioKnowledgeRepresentationLanguage无线电知识
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