简介:摘要随着无线通信系统的发展,在未来,系统信道可以选择为时间-频率选择性衰落频道,保证数据传输业务高速、可靠的同时,将成本降低。业界认为,未来移动通信系统中,MIMO-OFDM系统为最有可能被采用的技术方案,但在实际应用时,不仅要深入研究MIMO-OFDM系统的特性,还需要对信号处理中更为有效的算法进行研究与开发,基于此,本文中重点探讨了宽带无线通信中的MIMO-OFDM技术。
简介:InordertoimprovethevideotransmissionperformanceinMultiple-InputMultiple-OutputOrthogonalFrequencyDivisionMultiplexing(MIMO-OFDM)system,anewscheme,whichintegratesMultipleDescriptionCoding(MDC),LowDensityParityCheck(LDPC)codingandhybridspacetimecoding,isproposedinthisletter.Inparticular,ahybridspacetimecodingalgorithmiscombinedwithLDPCcodestoperformUnequalErrorProtection(UEP)ofMDCencodedvideostreams.ComparingwiththeUEPtransmissionwithonlyLDPCcodes,theproposedschemeachievesmorethan1dBgainintermsofSignaltoNoiseRatio(SNR)whenthePeakSignaltoNoiseRatio(PSNR)ofreconstructedvideoisabove30dB.
简介:Abi-caponbeamforming(BCB)algorithmformulti-inputmulti-output(MIMO)radarisdevelopedonthebasisofcorrelationdomain.Byvectorizingtheechomatrixanditstranspose,theconventionalcaponcostfunctionistransformedintobi-caponquadraticfunctions.Bycalculatingtwolowerdimensionalweightvectorswithsub-matricesofthecorrelationmatrix,BCBcansignificantlydecreasethecomputationalcomplexityandtherequirementoftrainingsamples.Inthepresenceofshortdatarecords,BCBcanachievebetterinterferencesuppressionperformancethanfullyadaptivecaponalgorithm.Simulationresultsarepresentedtodemonstratetheeffectivenessoftheproposedmethod.
简介:摘要:本文介绍了5G室内分布式Massive MIMO增强技术。首先概述了5G通信技术的基本原理和特点以及Massive MIMO技术的原理和优势。然后,讨论了室内分布式Massive MIMO系统的设计考虑和室内分布式Massive MIMO系统的信道特性分析。接着,阐述了性能评估和仿真结果关键点。最后,讨论了实现和部署室内分布式Massive MIMO系统的考虑因素,包括天线布置、系统硬件选择、信号处理和网络管理等方面。本文的研究对于推动5G室内通信技术的发展具有重要意义。
简介:CapacityofMIMOLAS-CDMAsystemsundermulti-pathfadingchannelswithtwodifferentcorrelatingmodelswerestudiedinthepaper.Influencesofthetwomodelsparametersoncapacitywereanalyzed.Thenumericalresultspresentthat:accordingtotheVariousScatteringEnvironmentscorrelatingmodel,whentheinner-elementsdistanceofantennasarrayislargethan0.5λ,correlationalmostdoesnottakefromthesystemcapacity;fortheSalz-Wintercorrelatingmodel,thespreadangleatreceiveristheotherkeyfactor,italsoinfluencethesystemcapacitygreatly.
简介:Thisarticleproposesatime/frequencysynchronizationalgorithminthemultipleinputmultipleoutput(MIMO)systems,inwhichtheperfectcompletegeneralizedcomplementaryorthogonallooselysynchronouscodegroupsareusedasthesynchronizationsequence.Thesynchronizationalgorithmisdividedintofourstages:1)synchronizationintimedomainbysignalautocorrelation;2)synchronizationinfrequencydomainbyfastFouriertransform(FFT);3)multipathdissociationusingcoherentdetectionandfinetimesynchronization;4)finefrequencyoffsetestimationbyphaserotation.Aspertheperfectcompletegeneralizedcomplementaryorthogonallooselysynchronouscodegroups,thecross-correlationandout-of-phaseauto-correlationforanyrelativeshiftbetweenanytwocodesisalwayszero.Thisidealpropertymakesthetime/frequencysynchronizationalgorithmsimpleandefficient.Thesimulationresultsshowthateveninthemultipathfastfadingchannelwithlowsignalnoiseratio(SNR),theMIMOsystemcangetsynchronizedbothinthetimedomainandfrequencydomainwithhighstabilityandreliability.
简介:新涡轮反复的接收装置结构为uplink被建议多重输入的多重产量的直角的频率分割多重存取(MIMO-OFDMA)系统。轮流出现空间的概括期望最大化(半自动地面防空系统)算法自然地在反复的接收装置的框架被嵌入用涡轮察觉者产量执行同步和察觉。在每次重复,期望步打算移开多重存取另外的异步的用户引起的干扰(MAI),和最大化步被利用估计要求的参数(即,预定偏移量,搬运人频率偏移量,隧道状态信息,等等)顺序为每个用户。模拟结果证明建议算法能仔细接近理想的接收装置的表演,当处理复杂性比常规察觉者相当低时。
简介:Multi-cellmulti-usermultiple-inputmultiple-output(MC-MU-MIMO)isapromisingtechniquetoeliminateinter-userinterferenceandinter-cellcochannelinterferenceinwirelesstelecommunicationsystems.AsthelargenumberofusersinthesystemandthelimitednumberofsimultaneouslysupportableuserswithMC-MU-MIMO,itisnecessarytoselectasubsetofuserstomaximizethetotalthroughput.However,thefullycentralizeduserselectionalgorithmsusedinsinglecellsystem,whichwillincurhighcomplexityandbackhaulloadinmulti-cellcooperativeprocessing(MCP)systems,arenotsuitabletoMC-MU-MIMOsystems.ThisarticlepresentsatwocascadeduserselectionmethodforMCPsystemswithmulti-cellblockdiagonalization.Inthispaper,alocaloptimalsubsetofusers,whichcanmaximizethelocalsumcapacity,isfirstchosenbythegreedymethodineverycooperativebasestationinparallel.Then,allthecooperativebasestationsreporttheirlocaloptimaluserstothecentralunit(CU).Finally,theglobaloptimalusers,whichcanmaximizetheglobalsumcapacityofMCPsystems,areselectedfromtheaggregatedlocaloptimalusersattheCU.Thesimulationresultsshowthattheproposedmethodperformscloselytotheoptimalandcentralizedalgorithm.Meanwhile,thecomplexityandbackhaulloadarereduceddramatically.
简介:Tomaximizethethroughputoffrequency-selectivemulticastchannel,theminimum-phaseFiniteImpulseResponse(FIR)precoderdesignisinvestigatedinthispaper.Thisproblemcanbesolvedintwosteps.Firstly,wefocusondesigninganonminimum-phaseFIRprecoderunderthecriterionofmaximizingthethroughput,anddeveloptwoefficientalgorithmsfortheFIRprecoderdesignfromperspectivesoffrequencydomainandtimedomain.Inthesecondstep,basedonthetheoryofspectralfactorization,thenonminimum-phaseFIRprecoderistransformedintothecorrespondingminimum-phaseFIRprecoderbyaclassiciterativealgorithmwithoutaffectingthethroughput.Numericalresultsindicatethattheachievablerateoftheproposeddesignhasremarkableimprovementoverthatofexistingschemes,moreover,thegroupdelayintroducedbytheFIRprecoderisminimized.
简介:Inthisarticle,resultsobtainedfromwidebandmultiple-inputmultiple-outputchannelmeasurementsat4.9GHzarepresented.Measurementswereperformedinanindoorhotspotscenariowithbothline-of-sightandnon-line-of-sightpropagationconditions.Verticalpolarizeduniformlineararrays(ULAs)withdifferentantennaspacingandorientationwereutilizedforinvestigatingtheimpactofantennaconfigurationsonthesystemperformance.Basedonmeasuredchannelimpulseresponses,thespatialcorrelationofULAisanalyzedandcomparedwiththetheoreticalvaluescalculatedfromthepowerazimuthspectrum.Followingthat,theeigenvaluestatisticsandcapacitywithrespecttoantennaspacingandorientationaregivenandcompared.Thediversity-multiplexingtradeoff(DMT)ofmeasuredchannelsatoperationalsignal-to-noiseratio(SNR)isalsopresented.ThereasonwhytheDMTofmeasuredchannelsismuchlowerthanthatofi.i.d.Rayleighchannelsisspecified.
简介:摘要:大规模多输入多输出(MIMO)天线阵列作为第五代(5G)及更高级别移动通信系统的关键技术之一,是当前时代研究的主要课题,这需要在实际实施中克服重大挑战。在本文中,我们分别讨论了5G背景下大规模MIMIO技术的发展方向、面临的挑战以及重点应用领域。