ofdm自适应资源分配算法的研究

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1、一1《1■■北京邮电大学硕士学位论文RESEARCHONADAPTIVERESOUCEALLOCATIONALGORITHML～INOFDMABSTRACTWiththedevelopmentofmobilecommunication，therequiredserviceisexpandedfromtraditionalvoicetodata，andnowtomultimedia．Withthehigherandhigherexpectationandrequirementtothemobilecommunicationspeedandquality,the

2、radiospectrumresourcesarebeingstrained．SoOFDM(OrthogonalFrequencyDivisionMultiplexing)isbecomemoreandmorepopularnowadaysforitshighfrequencyefficiencyandstrongabilitytoanti—disturb．Itisalsoregardedasthemaintechnologyofnextglobalmobilecommunicationsystem．OFDMisawidelyusedmulti-carrie

3、rmodulationschemewhichdividesthemultipathfadingchannelintoanumberofflatfadingchannels．Abigadvantageisthatpowerandinformationbitscanbeallocateddependingonthechannelcharacteristicstogetahighresourceusingratio．Inthispaper,theemphasisislaidononeofthekeytechniquesinOFDMsystems，theadapti

4、veresourceallocationtechniquesforOFDMsystems．Now,therearemanywaystosolvehowtoallocatetheresources．Generally,theycanbedividedintotwoclasses：fixedresourceallocationanddynamicresourceallocation．Fixedresourceallocationschemes，suchastimedivisionaccess(TOMA)andfrequencydivisionmultipleac

5、cess(FDMA)，assignanindependentdimension，e．g．timeslotorsubchannel，toeachuser．Afixedresourceallocationschemeisrigidregardlessofthecurrentchannelcondition．Thispapermostlyanalyzesdynamicallocationalgorithm，andstudiesthesingle—userandmulti-userresourceallocationalgorithmrespectively．Fir

6、stly,severaltypicaladaptiveresourceallocationalgorithmsareintroduced，andanimprovedalgorithmisproposedbasedonthesealgorithms．Theseexistingalgorithmsandimprovedalgorithmsarecomparedbysimulation．Then，theadaptiveⅡ北京邮电人学硕十学位论文sub-carrierpowerandbitallocationalgorithmsinmulti—userOFDMsys

7、temarestudied，andsomealgorithmsarealsoanalyzedbysimulation．KEYWORDS：resourceallocation，adaptive，bitallocation，sub-carrierallocation，OFDMm；．．1I．■第一章绪论。1．1研究背景⋯⋯⋯⋯⋯．．1．2问题的提出⋯⋯⋯⋯．1．3论文上作及研究意义．1．4本文结构⋯⋯⋯⋯⋯．第二章OFDM技术介绍。2．1OFDM基本原理⋯⋯．2．2OFI)M的实现⋯⋯⋯．2．2．1串并变换⋯⋯⋯⋯⋯2．2．2数字调制技术⋯⋯⋯2．2．3保护间隔和

8、循环前缀2．2．4傅立叶变换⋯⋯⋯⋯2．3OFDM关