测绘工程专业毕业论文中英文资料外文翻译文献gps通信系统全球移动通信系统

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1、毕业设计（论文）中英文对照资料外文翻译文献（此文档为word格式，下载后您可任意编辑修改！）要求1、外文翻译是毕业设计（论文）的主要内容之一，必须学生独立完成。2、外文翻译译文内容应与学生的专业或毕业设计（论文）内容相关，不得少于XXXX印刷符号。3•外文翻译译文用A4纸打印，需包含中文翻译和英文原文。4、年月口等的填写，用阿拉伯数字书写，要符合《关于出版物上数字用法的试行规定》，女口“2017年5月26日”。5、所有签名必须手写，不得打印。附件：外文原文GSM（GlobalSystemforMobileCommunication）Thesuccessofmobil

2、esystemsacrosstheworldisasignthatcommunicationismovingtowardsamorepersonalized,convenientsystem.Peoplewhohavetouseamobilephoneonbusinesssoonbegintorealizethattheabilitytophoneanytime,anyplaceinone'spersonalliferapidlybecomesanecessity,notaconvenience・Thespeedandrapiditywithwhichthepers

3、onalcommunicationsrevolutiontakesplaceis,unlikefixedtransmissionsystems,highlydependentontechnologyandcommunicationstandards・Formobilethethreekeyelementstoachievingservicetake-uparethecost,thesizeandtheweightofthephone,andthecostandqualityofthelink.Ifanyofthesearewrong,especiallythefir

4、sttwo,thenmarketgrowthisliabletobeseverelyrestricted.Thefixedtelephoneserviceisglobalandtheinterconnectionvariesfromcoaxialcabletoopticalfiberandsatellite.Thenationalstandardsaredifferent,butwithcommoninterfacesandinterfaceconversion,interconnectioncantakeplace.Formobiletheproblemisfar

5、morecomplex,withtheneedtoroamcreatinganeedforcomplex,networksandsystems.Thusinmobilethequestionofstandardsisfarmorecrucialtosuccessthanfixedsystems.Inaddition,thereisalsothevexedquestionofspectrumallocationinthemobilearea.Mobilesystemsoriginallyoperatedinanaloguemode(andstilldo)inthe45

6、0MHzbandmovinglaterto900MHzwithdigitalGSMandthento1800MHzwithpersonalcommunicationssystems.Thehistorytomobilitycansplitintogenerations.Thefirstgenerationsystemsweretheadvancedmobilephonesystems(AMPS)intheUS,totalaccesscommunicationsystems(TACS)inmostofEuropeandNordicmobiletelephonesyst

7、em(NMTS);whichwereallanaloguesystems・ThesecondgenerationisverymuchdominatedbythestandardfirstsetoutinEuropebythegroupspecialmobile(GSM)committee,whichwasdesignedasaglobalmobilecommunicationsystem・TheGSMsystemisbasedonacellularcommunicationprinciplewhichwasfirstproposedasaconceptinthe