协同通信和AF 和 DF 中继协议样本协同通信和 F AF 和和 F DF 中继协议本文档所提供的信息仅供参考之用，不能作为科学依据，请勿模仿。文档如有不当之处，请联系本人或网站删除。Abstract Nowadays,there is a trendfor munication system that the wholework systemis beingdynamic so that there are alwayshaving devicesshould beembedded andremoved.Conventional wiredmunication,due to the plexityof cabling,does notadapt to the modernmunicationsystem.Wireless techniquehas beenused widelybecause devicescan beconnected by electromagism wavewithout cabling.However,low transmittingreliablity becauseof inter-interferencebetweenele ctromagismwaves is the keyproblem ofwireless munication.Based onthis,this thesisinvestigates one of thetechnique calledcooperative munication and itcooperative protocols.Cooperative munication is avirtual multiple-input multiple-ou tput(MIMO)system.To increase the reliabilityof signal transmitted without increasing theamount ofmunication devices,this technologytries tomake each antennas haveone ormore partnersthat assist them to transmit the signal.In wirelesswork,the devicesnot onlytransmit theirown signalbutalsoassisttheir “partner ”to transmittheirsignalforsavingthecost of installationof additional antennas atboth senderIn this thesis,we focuson introducingthreereceiverandmainprotocols incooperative munication:Amplify-andForward(AF),Decode-and-Forward(DF)and Coded Cooperation(CC).The performanceand mathematicalequations of AF and DF areanalysed,and thenMATLAB programswere createdtosimulate the performanceof thesetwo protocols.About thethreeprotocols,the mainprocedures arealso introduced.Theperformance parison forAF and DF in differentsignal-to-noise(SNR)are本文档所提供的信息仅供参考之用，不能作为科学依据，请勿模仿。文档如有不当之处，请联系本人或网站删除。demonstrated.The resultpresents that the DFprotocolshasbetter performancethan AF.Finally,s omeremendationsandfuture workare mentionedat theend of the thesis.本文档所提供的信息仅供参考之用，不能作为科学依据，请勿模仿。文档如有不当之处，请联系本人或网站删除。文档如有不当之处，请联系本人或网站删除。文档如有不当之处，请联系本人或网站删除。文档如有不当之处，请联系本人或网站删除。文档如有不当之处，请联系本人或网站删除。文档如有不当之处，请联系本人或网站删除。文档如有不当之处，请联系本人或网站删除。文档如有不当之处，请联系本人或网站删除。ListofAbbreviationsandSymbols MIMOMultiple inputmultipleidentically distribution MLMaximum likelihoodSNR Signalnoise-ratio 本文档所提供的信息仅供参考之用， 不能作为科学依据，请勿模仿。文档如有不当之处，请联系本人或网站删除。1Introduction BackgroundWirelessmunicationis,recently,the fastestimproving segmentandmostwidelyusedway of the municationindustry.Forutilizingthebroadcastproperty ofelectromagism wave,the informationcan betransmitted inwireless environment,which savesmuch costfor cablingand makesthe changeof workstructure easily.On theother hand,as wirelesstechnique is used morewidely,there arealso manyproblems appearing.For example,the wirelesssig nalcan be affected a lot bythe transmittingmedium andinterferedwithother signal and the destination will receive not only thedirect wavebut also some extrawaves.These sortsof wavesignal willgenerate andform the received signalat thedestinat ion,which willresult insharply differingwith the original signalso thatdecreases the quality of signal andreliability.This iscalled multipath fading11.To solvethese problems,cooperative municationis oneof the methods.Cooperativemunication technique is amethod based on MIMO(multiple-inputmultiple-output)system.MIMO systemis amodel thatinstalling morethan oneantennas inboth thesender andreceiver,which achieveone signal is transmittedby differentchannels.In practical,d ueto thelimitation ofsize,power wasteand hardware,it is hard toinstall alotofantennas inone municationdevice sothat MIMOtechniqueishard toutilize inpractical directly.Thus,cooperative municationis amodel thatbuilds avirtual MIMOsystemamong existing antennas instead of buildingadditionalantennasbut achievesthe gain ofMIMOsystem8. 本文档所提供的信息仅供参考之用，不能作为科学依据，请勿模仿。文档如有不当之处，请联系本人或网站删除。Compared withtraditional transmittingmethod,cooperativemunication builds a cooperative workrelationshipbetweeneachantennawhich means eachantenna willhave ahelpertoassistthemtotransmitsignal and these helperantennascooperativeprotocols thatantennas obey AF(amplify 本文档所提供的信息仅供参考之用，不能作为科学依据，请勿模仿。文档如有不当之处，请联系本人或网站删除。Firstly,analy yzz ingtheconceptofcooperative municationandfind ingthe fundamentalprotocols sabout it.Secondly,finding theimportant describedequations and the usedcoefficients.Finally,use MATLABtosimulatethe proceduresofAFandDF and tryto get the BER(bit error rate)-SNR(signal-Noise ratio)diagram andpare thetheir performance.Thesis outlineThis reportincludes fiveparts:first partintroduce thebackground ofcooperative munication.Second partexplains sseveral literaturereviews sabout wireless,diversity technology,MIMO and cooperativeprotocols.Third andforth partsdemonstrate thesimulation a