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1、·ABSTRACTABSTRACTAsoneofthekeytechnologiesofwirelesscommunicationsystems,MultipleInputMultipleOutput(MIMO)provideshighsystemcapacityandrobustness.TherearethreemaintechniquesusedinMIMOtransmissionsystems:spatialdiversity,spatialmultiplexingandspatialmodulation.S
2、incetheyhavetheirownadvantages,thesetechniqueswillbeadaptedtodifferenttransmissionenvironment.Spatialdiversitytechniqueismainlyusedtoovercometheimpactofwirelesschannelfading.Spaceandtimedimensionsarejointlycodedtosendmultiplecopiesofadatastream.Atthereceiver,mu
3、lti-pathgaincanbeobtainedandthesystemperformancecanbeimproved.Basedonspacetimecoding,thisthesiswilldoresearchondistributedantenna
systemandspacetimeblockcodedspatialmodulationsysteminordertoobtaina
higherdatatransmitrate.Infirstchapter,thedevelopmentprocessofwi
4、relesscommunicationswillbe
overviewed.ThecurrentresearchstatusofdownlinkcommonMIMOtechniquesand
spacetimecodingwillbeintroduced.Inthesecondchapter,thesystemmodelandmathematicalmodelofthree
commonMIMOtransmissiontechniques,spacediversity,spacemultiplexingand
spa
5、tialmodulation,willbesummarized.Tobespecific,differentdimensionspacetime
blockcodes(STBCs)willbeintroducedandsimulated.Theadvantagesandshortages
ofthesetechniqueswillbeanalyzedandsimulated.Inthethirdchapter,thesystemmodelappliedinthischapterwillbefirstly
introd
6、uced.Then,theeffectofRayleighfadingandDopplerspreadwillbe
summarized.Pilotsymbolassistedmodulationandrecursiveleastsquaresalgorithm
willbeappliedinthesystemofchapter3.Furthermore,distributedantennasystemand
centralizedantennasystemwillbecomparedandsimulated.The
7、Matlabsimulation
resultsshowthatdistributedantennasystemcanobtainhigherstabilitythancentralized
antennasystem.Moreover,whencomparingthebetterperformanceofdistributed
antennasystemandcentralizedantennasysteminonecell,theareaofdistributed
antennasystemisbiggertha
8、nthatofthecentralizedantennasystem.Chapter4isthemostimportantpartofthethesis.AnewspacetimeblockcodedIII····ABSTRACTspatialmodulation(STBC-SM)technique,whichcombinedspacetime
