协同通信与AF和DF中继协议

1AbstractNowadays,thereisatrendforcommunicationsystemthatthewholenetworksystemisbecomingdynamicsothattherearealwayshavingdevicesshouldbeembeddedandremoved.Conventionalwiredcommunication,duetothecomplexityofcabling,doesnotadapttothemoderncommunicationsystem.Wirelesstechniquehasbeenusedwidelybecausedevicescanbeconnectedbyelectromagnetismwavewithoutcabling.However,lowtransmittingreliablitybecauseofinter-interferencebetweenelectromagnetismwavesisthekeyproblemofwirelesscommunication.Basedonthis,thisthesisinvestigatesoneofthetechniquecalledcooperativecommunicationanditcooperativeprotocols.Cooperativecommunicationisavirtualmultiple-inputmultiple-output(MIMO)system.Toincreasethereliabilityofsignaltransmittedwithoutincreasingtheamountofcommunicationdevices,thistechnologytriestomakeeachantennashaveoneormorepartnersthatassistthemtotransmitthesignal.Inwirelessnetwork,thedevicesnotonlytransmittheirownsignalbutalsoassisttheir“partner”totransmittheirsignalforsavingthecostofinstallationofadditionalantennasatbothreceiverandsenderInthisthesis,wefocusonintroducingthreemainprotocolsincooperativecommunication:Amplify-and–Forward(AF),Decode-and-Forward(DF)andCodedCooperation(CC).TheperformanceandmathematicalequationsofAFandDFareanalysed,andthenMATLABprogramswerecreatedtosimulatetheperformanceofthesetwoprotocols.Aboutthethreeprotocols,themainproceduresarealsointroduced.TheperformancecomparisonforAFandDFindifferentsignal-to-noise(SNR)aredemonstrated.TheresultpresentsthattheDFprotocolshasbetterperformancethanAF.Finally,somerecommendationsandfutureworkarementionedattheendofthethesis.2TableofContentsAbstractTableofcontainsListoffiguresListofabbreviationsandSymbols1Introduction..................................................................................................................................91.1Background.......................................................................................................................91.2Objectives.........................................................................................................................91.3Approaches.......................................................................................................................91.4Thesisoutline....................................................................................................................102LiteratureReview.......................................................................................................................122.1Overview...........................................................................................................................122.2Spatialdiversitytechnology..............................................................................................132.3BasicModelforWireless...................................................................................................132.3.1SISOsystem............................................................................................................132.3.2MIMOsystem.........................................................................................................142.3.3Cooperativemodel.................................................................................................142.4Cooperativeschemes........................................................................................................152.4.1Amplify-and-forwardmethod................................................................................162.4.2Decode-and-forwardmethod................................................................................162.4.3Codedcooperation.................................................................................................173SimulationandAnalysesofAF..................................................................................................213.1Overview...........................................................................................................................213.2Maximumlikelihoodmethod............................................................................................213.3SimulationandAnalysis.....................................................................................................213.3.1Thewholeprocedureandanalysis.........................................................................213.3.2Simulation..............................................................................................................243.4Summary...........................................................................................................................264SimulationandAnalysisofDF...................................................................................................274.1Overview..........................................................................................................................274.2Quantizationmethod.......................................................................................................2734.3ConvolutionalCodeandVite