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ID:12083367
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时间:2018-07-15
《蜂窝无线通信系统的研究英文翻译》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、蜂窝无线系统的研究专业班级:信息工程07-1班姓名:耿永鹏学好:200707070111郑州轻工业学院本科毕业设计(论文)——英文翻译题目蜂窝无线通信系统的研究学生姓名耿永鹏专业班级信息工程07-1班学号200707070111院(系)计算机与通信工程学院指导教师(职称)张娜(讲师)完成时间2011年5月30日7蜂窝无线系统的研究专业班级:信息工程07-1班姓名:耿永鹏学好:200707070111英文原文RESEARCHOFCELLULARWIRELESSCOMMUNATIONSYSTEMAbstractCellularcommunicationsystemsallowala
2、rgenumberofmobileuserstoseamlesslyandsimultaneouslycommunicatetowirelessmodemsatfixedbasestationsusingalimitedamountofradiofrequency(RF)spectrum.TheRFtransmissionsreceivedatthebasestationsfromeachmobilearetranslatedtobaseband,ortoawidebandmicrowavelink,andrelayedtomobileswitchingcenters(MSC)
3、,whichconnectthemobiletransmissionswiththePublicSwitchedTelephoneNetwork(PSTN).Similarly,communicationsfromthePSTNaresenttothebasestation,wheretheyaretransmittedtothemobile.Cellularsystemsemployeitherfrequencydivisionmultipleaccess(FDMA),timedivisionmultipleaccess(TDMA),codedivisionmultiplea
4、ccess(CDMA),orspatialdivisionmultipleaccess(SDMA).1IntroductionAwidevarietyofwirelesscommunicationsystemshavebeendevelopedtoprovideaccesstothecommunicationsinfrastructureformobileorfixedusersinamyriadofoperatingenvironments.Mostoftoday’swirelesssystemsarebasedonthecellularradioconcept.Cellul
5、arcommunicationsystemsallowalargenumberofmobileuserstoseamlesslyandsimultaneouslycommunicatetowirelessmodemsatfixedbasestationsusingalimitedamountofradiofrequency(RF)spectrum.TheRFtransmissionsreceivedatthebasestationsfromeachmobilearetranslatedtobaseband,ortoawidebandmicrowavelink,andrelaye
6、dtomobileswitchingcenters(MSC),whichconnectthemobiletransmissionswiththePublicSwitchedTelephoneNetwork(PSTN).Similarly,communicationsfromthePSTNaresenttothebasestation,wheretheyaretransmittedtothemobile.Cellularsystemsemployeitherfrequencydivisionmultipleaccess(FDMA),timedivisionmultipleacce
7、ss(TDMA),codedivisionmultipleaccess(CDMA),orspatialdivisionmultipleaccess(SDMA).Wirelesscommunicationlinksexperiencehostilephysicalchannelcharacteristics,suchastime-varyingmultipathandshadowingduetolargeobjectsinthepropagationpath.7蜂窝无线系统的研究专业班级:信息
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