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ID:307626
大小:95.00 KB
页数:6页
时间:2017-07-21
《光纤通信 毕业论文外文翻译》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、东华理工大学长江学院毕业设计外文翻译学生姓名:学号:09323119专业:信息工程系别:信息工程指导教师:职称:讲师二0一三年六月五日OriginalOpticalFiberCommunicationsTheGeneralSystemCommunicationmaybebroadlydefinedasthetransferofinformationfromonepointtoanother.Whentheinformationistobeconveyedoveranydistanceacommuni
2、cationsystemisusuallyrequired.Withinacommunicationsystemtheinformationtransferisfrequentlyachievedbysuperimposingormodulatingtheinformationontoanelectromagneticwavewhichactsasacarrierfortheinformationsignal.Thismodulatedcarrieristhentransmittedtothere
3、quireddestinationwhereitisreceivedandtheoriginalinformationsignalisobtainedbydemodulation.Sophisticatedtechniqueshavebeendevelopedforthisprocessbyusingelectromagneticcarrierwavesoperatingatradiofrequenciesaswellasmicrowaveandmillimeterwavefrequencies.
4、However,‘communication’mayalsobeachievedbyusinganelectromagneticcarrierwhichisselectedfromtheopticalrangeoffrequencies.Anopticalfibercommunicationsystemissimilarinbasicconcepttoanytypeofcommunicationsystem.Thecommunicationsystemthereforeconsistsofatra
5、nsmitterormodulatorlinkedtotheinformationsource,thetransmissionmedium,andareceiverordemodulatoratthedestinationpoint.Inelectricalcommunicationstheinformationsourceprovidesanelectricalsignal,usuallyderivedfromamessagesignalwhichisnotelectrical(e.g.soun
6、d),toatransmittercomprisingelectricalandelectroniccomponentswhichconvertsthesignalintoasuitableformforpropagationoverthetrans-missionmedium.Thisisoftenachievedbymodulatingacarrier,which,asmentionedpreviously,maybeanelectromagneticwave.Thetransmissionm
7、ediumcanconsistofapairofwires,acoaxialcableoraradiolinkthroughfreespacedownwhichthesignalistransmittedtothereceiver,whereitistransformedintotheoriginalelectricalinformationsignal(demodulated)beforebeingpassedtothedestination.However,itmustbenotedthati
8、nanytransmissionmediumthesignalisattenuated,orsuffersloss,andissubjecttodegradationsduetocontaminationbyrandomsignalsandnoise,aswellaspossibledistortionsimposedbymechanismswithinthemediumitself.Therefore,inanycommunicationsystemthereisamaximum
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