无线通信基础双语教学.ppt

WirelessCommunicationFundamentals Dr JiangZhu Professor DepartmentofMilitaryCommunicationEngineering SchoolofElectronicScienceandEngineering WiredVs WirelessCommunication WiredVs WirelessCommunication WiredVs WirelessCommunication Howdoessignalpropagate Howmuchattenuationtakeplace Howdoessignallooklikeatthereceiver Howdoessignalsusingthesamepropag ationchannel WiredVs WirelessCommunication ProvidecomprehensiveunderstandingoffundamentalprinciplesunderlyingwirelesscommunicationsandnetworkingPrinciplesinclude CharacteristicsandperformancelimitsofwirelesssystemsTechniquestoovercomethedifficulties GoalofThisCourse Outline Outline Email jiangzhu gfkd mtnjiangzhu Phone 7447713787179473Office 103room 4thDepartment sGeneralBuilding Courseinformation InstructorInformation Courseinformation TextWirelessCommunicationsandNetworkingbyJonW MarkandWeihuaZhuangReferenceModernWirelessCommunicationsbySimonHaykinandMichaelMoherLectureNotesbyDr JiangZhu CourseMaterial Courseinformation SomebasicknowledgeofcommunicationSomebasicknowledgeofsignalsandsystemsSomebasicknowledgeofprobabilityandstatistics Prerequisites Courseinformation ClassTime 18Lectures 36credithours Labs 4credithoursFinalexam Time schedule Courseinformation Experiment15 Homeworks ClassParticipation5 FinalExam80 Grading Outline Introductiontomaintopics Introductiontomaintopics Introductiontomaintopics Introductiontomaintopics Introductiontomaintopics Outline 1 1DefinitionofWirelesscommunication TransmittingvoiceanddatausingelectromagneticwavesinopenspaceElectromagneticwavesTravelatspeedoflight c 3x108m s Hasafrequency f andwavelength l c f l Whatiswirelesscommunication 1 1DefinitionofWirelesscommunication Propagationcharacteristicsaredifferentineachfrequencyband AMradio S Wradio FMradio TV TV cellular Whatiswirelesscommunication 1 1DefinitionofWirelesscommunication GroundWave Skywave Spacewave Whatiswirelesscommunication 1 1DefinitionofWirelesscommunication ProvidesmobilityAusercansendorreceiveamessagenomatterwhereheorsheislocatedAddedconvenience reducedcostEnablescommunicationwithoutinstallinganexpensiveinfrastructure 1 1DefinitionofWirelesscommunication Whyusewirelesscomm 1 1DefinitionofWirelesscommunication ThewirelesschannelWirelesschannelsareadifficultandcapacitylimitedbroadcastcommunicationsmediumModulation coding equalization diversityetc UsermobilityTrafficpatterns userlocations andnetworkconditionsareconstantlychangingHandoffandLocationmanagement Challengesofwirelesscomm 1 1DefinitionofWirelesscommunication Thefundamentalphysicalresourceinwirelesssystemsistheradiospectrum Thedevelopmentofwirelesscommunicationshasoftenasearchformoreefficientwaysofusingtheradiospectrum Challengesofwirelesscomm 1 1DefinitionofWirelesscommunication OSIModel Thislayerprovidesthephysicalmechanismfortransmittingbitsbetweenanypairofnodes Onepurposeofthedata linklayeristoperformerrorcorrectionofdetection thislayerisalsoresponsibleforthewayinwhichdifferentuserssharethetransmissionmedium Thislayerhasseveralfunctions oneofwhichistodeterminetheroutingoftheinformation Asecondfunctionisflowcontrol toensurethatthenetworkdoesnotbecomecongested 1 2Historyofwirelesscommunication 1864 Maxwellpredictsexistenceofelectro magnetic EM waves1887 HertzprovesexistenceofEMwaves firstsparktransmittergeneratesasparkinareceiverseveralmetersaway1890 Branlydevelopscohererfordetectingradiowaves1896 MarconidemonstrateswirelesstelegraphtoEnglishtelegraphoffice Beforethe BirthofRadio 1864 1896 1 2Historyofwirelesscommunication 莫尔斯电报和贝尔电话都是有线通信 当时人们认为电只能沿导线传输 可当时的英国科学家麦克斯韦尔不这样认为 早在1864年麦克斯韦尔就从理论上预言了电磁波的存在 他认为电能可以在空间以电磁波的形式存在 1864年麦克斯韦尔在英国皇家学院发表了他的第三篇著名论文 电磁场力学的理论 在这篇论文中 麦克斯韦尔严格推导出完善的电磁波方程 麦克斯韦尔方程 并得出电磁波的传播速度等于光速 30万公里 秒 的重要结论 1887年德国物理学家赫兹用实验证实了电磁波的存在证明了麦克斯韦尔预见的正确性 1895年 意大利的马可尼和俄国的波波夫把电磁波应用到无线电报通信中 但当时电波的传送距离较近 20 300公里 而且声音很微弱 只能用耳机收听 距离远了就听不见 直到1906年 26岁的美国青年 业余无线电爱好者德福雷斯特发明了具有放大能力的真空三极管后 通信技术有了突飞猛进的发展 先后出现了无线电广播 电视 无线电话 并发展到今天的计算机通信 卫星通信 光纤通信 网络通信 移动通信等 1 2Historyofwirelesscommunication TheBirthofRadio 1897 Marconiawardedpatentforwirelesstelegraph1897 First Marconistation establishedonNeedlesislandtocommunicatewithEnglishcoast1898 MarconiawardedEnglishpatentfortunedcommunication1898 WirelesstelegraphicconnectionbetweenEnglandandFranceestablished 1901 MarconisuccessfullytransmitsradiosignalacrossAtlanticOceanfromCornwalltoNewfoundland1902 FirstbidirectionalcommunicationacrossAtlantic1909 MarconiawardedNobelprizeforphysics 1 2Historyofwirelesscommunication TransoceanicCommunication 1914 Firstvoiceoverradiotransmission1924 BellLaboratoriesclaimthefirstmobile2 wayvoicebasedradiotelephone1920s MobilereceiversinstalledinpolicecarsinDetroit1930s Mobiletransmittersdeveloped radioequipmentoccupiedmostofpolicecartrunk1935 Frequencymodulation FM demonstratedbyArmstrong 1 2Historyofwirelesscommunication VoiceoverRadio 1946 Firstinterconnectionofmobileuserstopublicswitchedtelephonenetwork PSTN 1947 atBellLabs D H Ringdescribedthecellularnetworkideainaninternalmemo 1969 TheBellSystemmadecommercialcellularradiooperationalbyemployingfrequencyreuseforthefirsttime 1976 BellMobilePhonehas543paycustomersusing12channelsintheNewYorkCityarea waitinglistis3700people serviceispoorduetoblocking 1 2Historyofwirelesscommunication BirthofMobileTelephony 1979 NTT Japandeploysfirstcellularcommuni cationsystem1983 AdvancedMobilePhoneSystem AMPS deployedinUSin900MHzband1989 GroupeSp cialMobiledefinesEuropeandigitalcellularstandard1991 USDigitalCellularphonesystemintroduc ed1993 IS 95 CDMA digitalcellularsystemdepl oyedinUS 1 2Historyofwirelesscommunication CellularMobileTelephony 1995 FCCauctionsofffrequenciesinPersonalCommunicationsSystem PCS bandat1 8GHzformobiletelephony TheauctionmoneyforsixbroadbandPCSlicensedbands 120MHz almostreaches20billionUSdollars1999 ITUdecidesthenextgenerationmobilecom municationsystems e g W CDMA cdma2000 etc 2000s Third fourthgenerationcellularsystemstandards Bluetooth WiFi adhocnetworks sensornetworks 1 2Historyofwirelesscommunication PCSandBeyond 1 2Historyofwirelesscommunication HistoryofCellularCommunication 1 2Historyofwirelesscommunication Over80 ofworld spopulationhascellularcoverageOver3billioncellularsubscribersHalfoftheworld spopulationManydevelopedcountrieshavemoresubscribersthanpeople 1 2Historyofwirelesscommunication CellularPhonePenetration Cellularhasenjoyedexponentialgrowthsince1988IgnitedtherecentwirelessrevolutionAsiawayaheadoftherestoftheworldMuchhypein1990s greatfailuresaround2000 1 2Historyofwirelesscommunication CellularPhonePenetration 1 3Typesofwirelesscommunications MobileCellularNetworksWirelessDataNetworksMobileSatelliteCommunicationAdHocNetworksWirelessSensorNetworksGPSCordlessPhonePagingSystem WirelessCommunicationSystem 1 3Typesofwirelesscommunications MobileCellularNetworks 1 3Typesofwirelesscommunications Whatisacellularsystem FCCdefinesthecellularsystemas Asysteminwhichassignedradiospectrumisdividedintodiscretechannels whichareassignedingroupstogeographiccellscoveringacellulargeographicservicearea Asystemwhichusesradiotransmissionratherthanphysicalwirelinestoprovidetelephoneservice 1 3Typesofwirelesscommunications CellularSystemCharacterizedby HighmobilityprovisionWide rangeTwo wayvoicecommunicationHandoffandroamingsupportIntegratedwithsophisticatedpublicswitchedtelephonenetwork PSTN Hightransmitpowerrequiresatthehandsets 2W 1 3Typesofwirelesscommunications WirelessDataNetworks 1 3Typesofwirelesscommunications Wi Fishortfor WirelessFidelity isasetofstandardsforWLANcurrentlybasedontheIEEE802 11specifications WLANusingtheIEEE802 11HiperLANisaEuropeanStandard WirelessLAN 1 3Typesofwirelesscommunications WirelessLAN 1 3Typesofwirelesscommunications WirelessLAN 1 3Typesofwirelesscommunications WirelessPersonalAreaNetwork WPAN IEEE802 15 1BluetoothIEEE802 15 3UWBIEEE802 15 4ZigBeeRadios WirelessPAN 1 3Typesofwirelesscommunications WirelessPAN Bluetooth 1 3Typesofwirelesscommunications CoververylargeareasOptimizedforone waytransmissionRadio DAB andmovie SatTV broadcastingMosttwo waysystemsstrugglingorbankruptExpensivealternativetoterrestrialsystem MobileSatelliteCommunication 1 3Typesofwirelesscommunications Peer to peercommunications Nobackboneinfrastructure Routingcanbemultihop Topologyisdynamic AdHocNetworks 1 3Typesofwirelesscommunications AdHocNetworks 1 3Typesofwirelesscommunications WirelessSensorNetworks 1 3Typesofwirelesscommunications 1 4Developmentofwirelesscommunication 1 4Developmentofwirelesscommunication ViewwirelessfromdifferentAngles TelecomandDataNetworking TelecomInterest DataNetworkingInterest 1 4Developmentofwirelesscommunication 1 4Developmentofwirelesscommunication 1 4Developmentofwirelesscommunication SoftwareRadio JTRS CourseoutlineOverviewofwirelesscommunicationsSomehistoryApositiveviewofthefutureofwirelesscommunications Conclusions WhydoesFMsignalofferbetterreceptivequalitycomparedwithAMsignalinwirelesscommunicationsystem Problems