协作通信系统中的选择AF中继协议研究

本科毕业设计论文题目协作通信系统中的选择AF中继协议研究专业名称通信工程学生姓名XXX指导教师毕业时间2012.7西北工业大学明德学院本科毕业设计论文I目录摘要................................................................IABSTRACT...........................................................II第一章．绪论........................................................11.1研究背景及意义..............................................11.2论文结构....................................................3第二章．无线通信的基本介绍..........................................42.1无线通信的定义..............................................42.2无线通信的发展前景和趋势....................................42.2.1发展前景...............................................42.2.2发展趋势...............................................82.3无线信道.....................................................92.3.1无线信道定义...........................................92.3.2影响无线信道的因素....................................102.3.3无线信道的分集........................................112.4．MIMO系统的产生及其应运....................................152.4.1MIMO的产生...........................................152.4.2MIMO的应用...........................................162.5协作分集....................................................172.5.1协作分集的产生和发展趋势..............................172.5.2协作分集的优点........................................182.5.3协作分集面临的问题....................................19第三章协作通信的应用与协议........................................203.1协作通信的应用.............................................203.2协作通信的协议............................................21第四章．选择AF中继协议研究........................................244.1中继信道及协议.............................................244.1.1中继信道的概念........................................244.1.2中继信道的原理........................................244.1.3中继协议存在的问题及解决的方法........................244.2协作策略...................................................254.3中继选择协作通信方法研究...................................284.3.1系统模型..............................................284.3.2最优中继选择协作通信方法..............................314.4利用MGF方法的SER分析.....................................324.5调和平均的简单MGF表达.....................................33第5章总结与展望..................................................37西北工业大学明德学院本科毕业设计论文II5.1本文工作总结...............................................375.2未来工作展望...............................................37参考文献...........................................................39致谢...............................................................40毕业设计小结.......................................................41西北工业大学明德学院本科毕业设计论文I摘要在无线通信网络中，由于用户终端受体积、功率等各种条件的约束，给多天线技术的实施带来了困难。协作分集技术作为一种虚拟多天线技术，可以通过中继节点的协作，对传输的信息进行转发处理，以使网络用户的能耗显著降低，保证终端的数据接收，优化网络性能。协作分集技术已经成为当前无线通信领域的一个新的研究热点。对于协作传输系统中的中继选择问题，Laneman和Wornell首先提出了在两跳多分支(Two-HopMultipleChannels)的协作网络中，利用所有可获得的中继节点进行数据转发，即“全中继协作”(APR)方案。由于APR方案需要利用所有可获得的信道，因而在多中继场景下，APR方案的频谱效率较低。中继选择(RS)方案克服了低频谱效率的问题，大致可分为单中继选择(SRS)方案和多中继选择(MRS)方案。在SRS中，文献选择端到端SNR最大的中继节点，从而带来全分集增益(Fulldiversitygain)。文献提出了最优最差信道的中继选择(BestWorseChannel)方案，也实现了全分集。在MRS中，文献提出在功率限制下，基于最大接收SNR的RS方案。文献提出在总能量受限的情况下选择中继节点，从而差错概率最小。通过协作通信中选择AF中继协议研究。考虑AF协作通信系统的SER性能。首先，为两个独立的指数随机变量的调和平均值推导了一个简单的闭式MGF表达。然后，基于这个简单的MGF表达，得到了采用M-PSK和M-QAM调制的AF协议系统的闭式SER表达式。次之，提出了SER近似解来显示系统的渐进性能，这个近似解在高信噪比下是紧的。最后，基于紧的近似，能够为AF协作系统确定最优功率分配。关键词：协作通信，中继选择，放大转发，协作分集西北工业大学明德学院本科毕业设计论文IIABSTRACTTotheimplementationofmulti-antennatechnologyinwirelesscommunicationnetwork,theuserterminalbytheconstraintsofsize,powerandotherconditionsdifficult.CooperativeDiversityasavirtualmulti-antennatechnology,throughthecollaborationoftherelaynode,thetransmissionofinformationtobeforwardedtosignificantlyreducetheenergyconsumptionofnetworkusers,toensurethattheterminaldatareceptionandoptimizenetworkperformance.CooperativeDiversityhasbecomeanewhotspotinthefieldofwirelesscommunications.Forrelayselectionincooperativetransmissionsystem,LanemanandWornellfirstproposedinthecollaborativenetworkoftwo-hopmulti-branch(Two-hopMultipleChannels),theuseofallavailablerelaynodestoforwarddata,namely,allfollowingthecollaboration(APR)program.APRprogramsneedtouseallavailablechannels,andthusmulti-relayscenario,thelowerthespectralefficiencyoftheAPRprogram.Relayselection(RS)schemetoovercometheproblemoflowspectralefficiency,canbedividedintosingle-relayselectionscheme(SRS)andthemulti-relayselectionscheme(MRS).IntheSRS,theliteraturetoselectthemaximumend-to-endSNRoftherelaynode,inordertobringthefulldiversitygain(Fulldiversitygain).Proposedintheliteratureofoptimalworst-casechannelrelayselection(theBestWorseChannel)programtoachievefulldiversity.InMRS,theliteratureonthepowerconstraints,basedonthemaximumreceivedSNR(SNR)oftheRSprogram.Theliteratureselectedinthecaseoftotalenergy-constrainedrelaynode,theminimumerrorprobability.SelecttheAFrelayprotocolforcollaborativecommunications.ConsidertheSERperformanceoftheAFcooperativecommunicationsystem.First,asimpleclosedMGFexpressionisderivedfortheharmonicmeanoftwoindependentexponential西北工业大学明德学院本科毕业设计论文IIIrandomvariables.Then,basedonthissimpleMGFexpression,hasbeenclosedSERexpressionfortheAFprotocolsystemusingtheM-PSKandM-QAMmodulation.FollowedbytheSERtodisplaytheappro