专业英语作业移动通信的发展史Word文档下载推荐.docx

专业英语作业移动通信的发展史Word文档下载推荐.docx

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2016/6/21Tuesday

Thisarticlemainlyintroducesthehistoryofthedevelopmentofmobilecommunication.Combinedwiththefirstgeneration,secondgeneration,thethirdgeneration,thecoretechnologyofthefourthgenerationmobilecommunicationofeachgenerationcommunicationtechnologyadvantagesanddisadvantageswereintroduced,toeveryoneofeverygenerationmobilecommunicationiswhat,andtheirproductionanddevelopmenthaveasystemofunderstanding.

IntroductionofTheDevelopmentofMobileCommunication

Abstract：

Thisarticlemainlyintroducesthehistoryofthedevelopmentofmobilecommunication.Combinedwiththefirstgeneration,secondgeneration,thethirdgeneration,thecoretechnologyofthefourthgenerationmobilecommunicationofeachgenerationcommunicationtechnologyadvantagesanddisadvantageswereintroduced,toeveryoneofeverygenerationmobilecommunicationiswhat,andtheirproductionanddevelopmenthaveasystemofunderstanding.

Keywords：

mobile;

communication;

development

Introduction:

Mobilecommunicationreferstothecommunicationandexchangeofinformationbetweenthetwopartiesatleastonesideinthemobileenvironment,whichincludesthecommunicationbetweenthetwosidesofthecommunicationandthemobileobjectandthefixedpointinthemobileenvironment.Mobilecommunicationispartofanintegralpartofmoderncommunicationsystems,mobilecommunicationappearedtobreakthefixedrelationshipbetweencommunicationandplace.ItuseswirelesstechnologytosolvetheInternetcan'

tsolvethemobility,sothatpeopleinthemobileinformationacquisitionandinteractive.Itsdevelopmentandpopularizationhaschangedthesociety,butalsochangedthewayoflifeofmankind,sothatpeopleunderstandtheeraofhigh-speedinformationoftheatmosphere.

Modernmobilecommunicationtechnologyoriginatedinthetwentiesofthe20thcentury,themidseventiesofthe20thcentury,itusheredintherapiddevelopmentofmobilecommunication,untilnowtheOFDMTechnologyinthefourthgenerationcommunicationapplicationandthedevelopmentofmobilecommunicationwitheachpassingday.

1.Thefirstgenerationofmobilecommunicationsystem（1g）

Firstgeneration（1g）isthegenerationofmovingcommunicationsystem,simulationofcellularmobilecommunicationsystems,theuseofanalogmodulationandmultipleaccesstechniqueisfrequencydivisionmultipleaccess（FDMA）,themodulationisafrequencymodulation（FM）,themainbearingvoiceservice.ThefirstgenerationmobilecommunicationtotheUnitedStatesofAmerica'

sAMPSsystemandtheEuropeanTACSastherepresentative,ourcountryinthelate80'

s,introducedtheTACStechnology,andbuiltthefirstpublicmobilecommunicationnetworkinChina.

Duetodifferentcountriesadoptdifferentstandard,differentbandandchannelbandwidth,roaminguserisnotconvenient,makingthefirstgenerationofmobilecommunicationsystemjustaregionalmobilecommunicationsystem,inaddition,inuseprocess,analogcellularmobilecommunicationsystemexposedalotofproblems,suchasspectralefficiencylow,singletypeofbusinessandthecallinterruptrateishigh,communicationequipment,heavy,butthethemainproblemisthebandresourceandcommunicationcapacityandgrowingofmobilecommunicationusersoflargecapacity,multiserviceandhighqualityserviceofmobilecommunicationdemandcontradictionhavebecomeincreasinglyprominent.Demandtopromotethedevelopment.Atthistimetheemergenceofdigitalsignal,allowspeopletosee,thetransmissionofdigitalsignalscanbeatransmissionoftheanalogsignalanddigitalsignalthanthatofanalogsignalshavemoresuperiorperformance,strongconfidentiality,errorpronetorestoreanddigitalcommunicationthananalogcommunicationhavemorekindsofbusiness.Makepeoplelookfromanalogcommunicationtodigitalcommunication.

2.Thesecondgenerationofmobilecommunicationsystems（2g）

2G（SecondGeneration）Thesecondgenerationmobilecommunicationsystem,ithastwokindsofmultipleaccessmethods,onekindistimedivisionmultipleaccess（TDMA）,multipleaccess（CDMA）isakindofcodepoints.RepresentativesofTDMAIStheEuropeanGSMsystem,therepresentativeoftheCDMAIStheIS-95systemoftheUnitedStates.GSMstandardsystemmoreperfect,thetechnologyisrelativelymature.Comparedwiththefirstgenerationofmobilecommunicationsystem,thesecondgenerationmobilecommunicationsystem,thefrequencyandtimeusedincombinationtoaddressing,improvetheutilizationrateofthespectrum,canprovidegreatercapacity;

Anti-interferenceandantifadingabilityenhancement,canguaranteegoodvoicequality.Theconfidentialityofthesystemisbetter;

Butthelowspeedofdatatransmission,databusinessdevelo