资源描述:
《现代移动通信 毕业论文外文翻译 (2)》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、一、英文原文ModernmobilecommunicationtechnologyInnowhighlytheinformationsociety,theinformationandthecorrespondencehavebecomethemodernsociety“thelife”.Theinformationexchangemainlyreliesonthecomputercorrespondence,butcorrespondstakesthetransmissionmethod,withthesensingtechnology,
2、thecomputertechnologyfusesmutually,hasbecomeinthe21stcenturytheinternationalsocietyandtheworldeconomicdevelopmentpowerfulengine.Inordertoofadaptthetimerequest,thenewgenerationofmobilecommunicationtechnologyseasonableandlives,thenewgenerationofmobilecommunicationtechnology
3、isthepeoplesaidthatthirdgeneration'scorecharacteristicisthewidebandaddressingturnsonnon-gaproamingbetweentherigidnetworkandnumerousdifferentcommunicationssystem's,gainsthemultimediacommunicationservices.Alongwiththetimeprogress,thetechnicalinnovation,people'sliferequest's
4、enhancement,themobilecommunicationtechnologyrenewalspeedisquiteastonishing,almosteveryothertenyearmobilecommunicationtechnologyhasatransformationupdate,fromthe1980s“themobilephone”topresent's3Ghandset,duringhashadtwomobilecommunicationtechnologytransformation,transitsfrom
5、1GAMPSto2GGSM,fromGSMtoIMT-2000(i.e.3Gtechnology).Knowsmodernonmethemobilecommunicationtechnologytohavethefollowingseveralaspectimportanttechnology:1.widebandmodulationandmultipleaccesstechniqueThewirelesshighspeeddatatransmissioncannotonlydependonthefrequencyspectrumcons
6、tantlytheexpansion,shouldbehigherthanthepresentnumbermagnitudeatleastinthefrequencyspectrumefficiency,mayusethreetechnologiesinthephysicallevel,namelyOFDM,UWBandfreetimemodulationcode.OFDMwithotherencodingmethod'sunion,nimblyOFDMandTDMA,FDMA,CDMA,SDMAcombinesthemultipleac
7、cesstechnique.Inthe1960stheOFDMmulti-channeldatatransmissionhassucceededusesincomplexandtheKathrynhighfrequencymilitarychannels.OFDMhasusedin1.6Mbit/shighbitratedigitalsubscriberline(HDSL),6Mbit/sasymmetricaldigitalsubscriberline(ADSL),100Mbit/sreallyhighspeedfiguresubscr
8、iber'sline(VDSL),digitalaudiofrequencybroadcastanddigitalvideobroadcastandsoon.OFDMapplieson5GHz