通信论文-lte的关键技术和发展.doc

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- 层上〔像帧构造、时分设计、同步等〕。FDD-LTE系统空口上下行传输采用一对对称的频段接收和发送数据，而TDD-LTE系统上下行则使用一样的频段在不同的时隙上传输，相对于FDD双工方式，TDD有着较高的频谱利用率。
本课题主要研究TD-LTE和FDD-LTE的技术原理、基于OFDM的多址接入技术、基于MIMO\SA的多天线技术等。
关键词：TD-LTE，FDD-LTE，OFDM，MIMO\SA
ABSTRACT
LTE(LongTermEvolution,a long term evolution)is posed of 3GPP(The3rdGenerationPartnershipProject,the third generation partnership project)to organize the formulation ofUMTS(UniversalMobileTelemunicationsSystem,a universal mobile telemunication system)long term evolutionof the technical standards,in 2004Decemberofficially launchedthe projectinTorontoand the3GPPTSGRAN#26 introducesOFDM(OrthogonalFrequencyDivisionMultiple*ing,orthogonalfrequency division multiple*ing)and MIMO(Multi-Input& Multi-Output,multiple input multiple output)and other keytransmission technology,significantlyincreases the spectral efficiencyand data transmission rate(20Mbandwidth of 2*2MIMOin 64QAMcases,theoreticaldownlinkma*imum transmission rate of 201Mbps,after theremoval ofthe signaling overheadwas about 140Mbps,but according to thelimit,the actual networkand terminalcapacitygenerallydownlink peak rate is 100Mbps,on thebehavior of 50Mbps),andsupport for multiplebandwidth allocation:,3MHz,5MHz,10MHz,15MHzand 20MHz,andsupportthe global mainstream2G/3G band andsome of the newband,thus thespectrum allocationmore fle*ible,system capacityand coveralso significantly enhance network architecture ismore flatsimple,reduces the networknode and theple*ity of the system,thus has reduced the systemdelay,but also reduces thecost ofnetwork deployment and LTE system to supportinteroperabilitywith other system has twotypes:FDD-LTE andTDD-LTE,.,frequency division duple*time division duple*LTEsystem andLTE system,the maindifference between the twois that physicallayertechnologyon theairinterface(likeframe structure,t