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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 莫爾斯電報(bào)和貝爾電話都是有線通信 當(dāng)時(shí)人們認(rèn)為電只能沿導(dǎo)線傳輸 可當(dāng)時(shí)的英國科學(xué)家麥克斯韋爾不這樣認(rèn)為 早在1864年麥克斯韋爾就從理論上預(yù)言了電磁波的存在 他認(rèn)為電能可以在空間以電磁波的形式存在 1864年麥克斯韋爾在英國皇家學(xué)院發(fā)表了他的第三篇著名論文 電磁場力學(xué)的理論 在這篇論文中 麥克斯韋爾嚴(yán)格推導(dǎo)出完善的電磁波方程 麥克斯韋爾方程 并得出電磁波的傳播速度等于光速 30萬公里 秒 的重要結(jié)論 1887年德國物理學(xué)家赫茲用實(shí)驗(yàn)證實(shí)了電磁波的存在證明了麥克斯韋爾預(yù)見的正確性 1895年 意大利的馬可尼和俄國的波波夫把電磁波應(yīng)用到無線電報(bào)通信中 但當(dāng)時(shí)電波的傳送距離較近 20 300公里 而且聲音很微弱 只能用耳機(jī)收聽 距離遠(yuǎn)了就聽不見 直到1906年 26歲的美國青年 業(yè)余無線電愛好者德福雷斯特發(fā)明了具有放大能力的真空三極管后 通信技術(shù)有了突飛猛進(jìn)的發(fā)展 先后出現(xiàn)了無線電廣播 電視 無線電話 并發(fā)展到今天的計(jì)算機(jī)通信 衛(wèi)星通信 光纖通信 網(wǎng)絡(luò)通信 移動通信等 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