OFDM系統(tǒng)高效接收方法的研究.pdf

1、中國科學技術(shù)大學博士學位論文OFDM系統(tǒng)高效接收方法的研究姓名：劉俊琳申請學位級別：博士專業(yè)：通信與信息系統(tǒng)指導(dǎo)教師：朱近康20060401中國科學技術(shù)大學博士論文AbstractAbstractThisdissertationisdevotedtotheresearchontheOFDMcommunicationtechniquesinthewirelessmobilecommunicatibnenvironments，includi

2、ngsomehi出一efficienttransmissiontechniquesThisdissertationbeginswiththebasicintroductionofOFDMtechniquesandasummaryofsinglecarriertechniqueandseveralexistingmulticarriertechniquesinordertoclarifythedifferencebetweentheOFD

3、MandtheothermulticarriertechniquesTheresearchontheOFDMsystemisofgreatpracticalvaluessincemanyoftheexistingmulticarriertechniquescanbefulfilledthroughOFDMmoduleandmanyusefulresultsinOFDMsystemarealsoapplicabletoothermulti

4、carriersystemsThisdissertationmainlyfocusesonsomehighefficienttransmissiontechniques，including吐1ehigh—efficienttime—frequencysynchronizationalgorithm，mehigh—efficientchannelestimationalgorithmbasedonpilotarrangementandll

5、lehi曲一efficientadaptivechannelestimationalgorithminOFDMsystemsInordertoillustratethenecessaryofOFDMhilgh—efficientcommunicationtechniquesinthewirelessmobilecommunicationenvironments，thisdissertationanalysestheperformance

6、influenceofOFDMsystemsduetothetimeandfrequencysynchronizationerrorsanddetailedlyin仃oduestheexistingtimeandfrequencysynchronizationalgorithmsandtheircorrespondingmeritsanddemeritsThisdissertationalsoclanitiesthecharacteri

7、sticsofwirelessmobilecommunicationenvironmentsin0FDMsystemssummarizestheexistingchannelestimationalgorithmsanddetailedlydescribesthechannelestimationalgorithmsbasedonpilotarrangementandtheircorrespondingmeritsanddemerits

8、Intheresearchofhighefficienttime—frequencysynchronizationalgorithmsofOFDMsystems，thisdissertationpresentsanewtimeandfrequencysynchronizationmethodusedinwirelessmobilecommunicationenvironmentsThismethodisbasedonthefrequen

9、cydomaincorrelationandthemaximumlikelihoodtheoriesandcallsolvetheproblemsintheexistingtimeandfrequencysynchronizationalgorithmsThismethodUSeSonetrainingsequenceofjustonesymbolandthedesignofthesymbolispresented強gtimesynch

10、ronizationandcarrierfrequencyoffsetestimationcanbeachievedsimultaneouslyandthefrequencysynchronizationalgorithmcanextendthefrequencyacquisitionrangetonearlythewholeusefulOFDMsignalbandwidthThefrequencysynchronizationalgo

11、rithmcarlalsoovercometheambiguityproblemexistingincarrierfrequencyoffsetestimationAfastrealizingalgorithmispresentedinthedissertationteducethecalculatingcomplexityinordertomakethemethodeasiertobeimplemented111esimulation

12、resultsdemonstratetheefficacyofthemethodIntheresearchofthehigh—efficientchannelestimationalgorithmbasedonpilotarrangement，thisdissertationproposesarobustpilot—assistedchannelestimationmethodforOFDMsignalsinRayleighfading

13、channelThemethodisbasedonthetheorythatthecalculatingcomplexitycanbegreatlyreducedwhenthefilterforchannelestimationisperformedinDopierspreadingdomainofwirelessmobilecommunicationenvironmentsinOFDMsystemsUsingthewayofMostS

14、ignificantTap(MST)selectionandpolynomialfiltering，themethodconductsthetime—frequencyfilteringformeLeastSquare(LS)estimationresultsofpilotsymbolsThemethodissimpleandneednotknowthestatisticcharacteristicofthepracticalchann

15、el，suchasthechannelcorrelationmatrixandsignaltonoiserate(SNR)Themethodcanbeusedinrectangularpilot—assistedgeometryandcanbeeasilyrealizedinpracticalOFDMsystemsThesimulationresultsshowthatthemeansquareerror(MSE)performance

16、ofthemethodisgreatlyimprovedwhenthemethodiscomparedwithLSandMSTestimationmethodincombpilotassistedgeometryandthebiterrorrate(BER)performanceofthemethodapproachesthatoftheidealchannelestimationinrectangularpilotassistedge