通信系统演进介绍

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1、数字无线传输宽带无线与多媒体中心王德胜20112021/7/171第1章概论1.1引言☆移动通信已成为当代通信领域内发展潜力最大、市场前景最广的热点技术，☆移动通信用户的增长远远超过了人们的预期，☆未来的无线便携终端数量会超过目前计算机联网的数量，☆其业务也从面向语音通信转变为面向多媒体数据通信2021/7/172展望☆高频谱效率☆高功率效率☆高性价比☆高质量的服务体系：扁平、透明、按需区分服务2021/7/173☆传输方式变化☆交换方式变化☆服务内容变化☆用户容量增大☆覆盖范围与全球漫游☆效率提高1.2从1G到4G的发展2021/7/174Europeanresearcho

2、n3Gstartedin1989withintheRACEIprogramand1991inRACEIIEuropeanresearchonsystemsbeyond3Gstartedin1999withintheISTprogram1980s1990s2000s2010s1G+1G2G+2G3G+3GBeyond3G+Beyond3GAnalogWidebandDigital???DigitalEuropeanresearchon3Gcontinuedin1995withintheACTSprogramFrameworkProgram6onfuturesystemsfull

3、commercialdeploymenttrialsstandardisationresearchEvolutionofmobilecommunicationsystems2021/7/175WirelessdataalreadybeintroducedinsecondgenerationmobileFirstGenerationAnalogueCircuitswitchedBasicvoicetelephonyLowcapacityLimitedlocalandregionalcoverageSecondGenerationDigitalCircuitswitchedVoi

4、ceplusbasicdataapplicationsLowdataspeedEnhancementstowardspacketswitchinghigherdataratesTrans-nationalandglobalroamingDigitalPacketandcircuitswitchedAdvanceddata(multimedia)applicationsFastdataaccessGlobalcoverageGlobalroamingThirdGenerationBeyondThirdGenerationDigitalPacketswitchedAllIPbas

5、ed(IPv6)MoreadvancedmultimediaapplicationsUserincontrolFlexibleplatformofcomplementaryaccesssystemsHighspeeddataImprovedQoSGlobalcoverageGlobalroaming5.1.3Paradigmshiftfrom1stgenerationtowardsbeyond3G2021/7/1762021/7/177一体化网络架构Wi-Fi(WaveLAN)RadioHubCable,xDSL,V9010/100-BaseTWirelessLANBluet

6、oothWirelessPANMultimedia&MessagingServerintegratedvoiceanddatavideopostcardsin-callimageup/downloadcodecconverterbandwidthmanagerstore&forwardplaybackContentMicroBSBTSUMTS/GSMCDMA2000WirelessBackboneandGatewaysLocationServicesIPNetwork2021/7/178Driversof3GBeyond3Gevolution…butdifficulttoex

7、tendtohigherdataratewithCDMAonlytechnology;toprovidevariousserviceswithdifferentQoStohaveenoughfrequencyresourcetoaccommodatemoresubscribersDrawbackLowsystemcapacityLowspectrumefficiency02519981999200020015075100125150Tbit/dayRealTime(e.g.Voice)NonRealTi