數(shù)字無線電廣播的若干關(guān)鍵問題研究.pdf

1、東南大學(xué)博士學(xué)位論文數(shù)字無線電廣播的若干關(guān)鍵問題研究姓名：賽和德申請學(xué)位級別：博士專業(yè)：信號與信息處理指導(dǎo)教師：吳樂南2001.9.1SoutheastUniversity／RadioEngineeringDepartmentResearchonSeveralKeyProblemsofDigitalRadioBroadcastingAbstractDigitalradiotransmissiontechniquesofferthepro

2、spectofimprovedreceptioncomparedwithanaloguesignalsandarebeingintroducedforradiobroadcastingintheshortwavebandsThecodingschemeadoptedplaysanimportantpartinachievingahighqualityjnthepresenceofnoiseandfadingwhichcanbeparti

3、cularlyseverefordigitalradiomondiale(DRM)receiversThisdissertationcomparestheperformanceofpuncturedconvolutionalcodesandturbocodesunderthechannelsconsideredtobebroadcastradiotransmissionchannelsproposedbvITU—Rcircular1et

4、ter10／LCCE／39TurbocodesareaclassofforwarderrorcorrectioncodesthatofferenergyelficienciesclosetothelimitspredictedbyinformationtheoryThefeaturesofturbocodesincludeparallelcodeconcatenation，recursiveconvolutionalencoding，n

5、on—uniforminterleavingandarlassociatediterativedecodingalgorithmAlthoughtheiterativedecodingalgorithmhasbeenprimarilyusedforthedecodingofturbocodesitrepresentsasoluliontoamoregeneralclassofestimationproblemsAdatasetdirec

6、tlyorindirectlydrivesthestatetransitionsoftwoormoreMarkovprocesses，theoutputofoneormoreoftheMarkovprocessesisobservedbynoisebasedontheobservationstheoriginaldatasetisestimatedAtIowsignal—to—noiseratiostheprocessofphasees

7、timationandtrackingbecomesdifficulttoperformAdditionallytheiterativedecodingrequirespreciseestimatesofthechannelgainandnoisevarianceThefirstsignificantcontributionofthisdissertationisastudyofseveralmethodsofchannelestima

8、tionsuitablespecificallyforpuncturedconvolutionalcodedsystemsThecombinationofpuncturedconvolutionalencodinginterleavinganddifferentiallyencodedM—arydifferentialamplitudephageshiftkeying(DAPSK)formsanattractivetransmissio

9、nschemebecauseitcombinesthebenefitsoferrorcorrectionwiththesimplicityofnoncoherentdetectionTheuseofaninterleaverhasthepotentialtogreatlyenhancetheerrorcorrectingabilityofthecode，providedthatasuitabledecoderstructureisuse

10、dInthisdissertationaniterativedecoderstructuresimilartotheoneusedfordecodingturbocodesisproposedforusewiththistransmissionschemenleresultingtechniqueisappliedtoadditivewhiteGaussiannoise(AWGNlchannelForthischannelmodel，a

11、novelsoft—outputdecoderisderivedandthesystemperformanceintermsofthebiterrorrate，isinvestigatedbymeansofcomputersimulationInthisapplicationtheproposedsystemworksverywell。notonlyprovidingperformancethatissignificantlybette

12、rthantraditionalnoniterativetechniquesbutalsomanybettersthananticipatedThethirdsignificantcontributionofthisdissertationjsaproposedmethodfornon—unifo徹M—aryDAPSKsignalingoveranAWGNandRayleighfadingchannelsTheperformanceof

13、anon—uniformM—DAPSKwithpuncturedconvolutionalcodingisinvestigatedwherethegoalistoprovideunequalerrorprotectionformultiresolutionsourceencodedanalogueinformationTheresultsshowthatthecodingcanbeusedwithlion—uniformM—DAPSKm