通信工程专业英语论文翻译.doc

《通信工程专业英语论文翻译.doc》由会员上传分享，免费在线阅读，更多相关内容在工程资料-天天文库。

1、CDMAversusTDMATermPaper:DTEC6810Submittedby:SabareeshwarNatarajan.Fall2006DTEC6810CommunicationTechnologyCDMAVsTDMAintravel:BothGSMandCDMAcanbefoundacrossUnitedStates,whichdoesn'tmeanthatitdoesn^tmatterwhichtechnologywechoose・Whenwetraveldomesticallyitispossiblethatwer

2、eachareaswheredigitalserviceisnotavailable.Whiletravelingbetweenplacesitispossiblethatwereachcertainruralareaswereonlyanalogaccessisoffered.CDMAhandsetsofferanalogcapabilitieswhichtheGSMdon'toffer.AnotherdifferencebetweenGSMandCDMAisinthedatatransfermethods・GSM'shigh-s

3、peedwirelessdatatechnology,GPRS(GeneralPacketRadioService),usuallyoffersaslowerdatabandwidthforwirelessdataconnectionthanCDMA'shigh-speedtechnology,whichhasthecapabilityofprovidingISDN(IntegratedServicesDigitalNetwork)withspeedsasmuchas144Kbps.GSM'sbenefitsovertheCDMAi

4、ndomesticpurposearethatGSMusesSIMcardthatidentifiesauserandstorestheinformationinthehandset.TheSIMcardcanbeswappedbetweenhandsets,whichenabletomoveallthecontactstothenewhandsetwithease.CDMAcanhavethisflexibilitywiththeirownservicethatstoresdataontheoperator'sdatabase.T

5、hisserviceallowstheusertoswapdata^sbetweentwohandsetswithalittletrouble,buttheadvantageisitcanbedonewhenthehandsetisevenlostbutinGSMtechnology,whenahandsetislost,SIMcardisalsolostwithit.WhenitcomesforinternationalroaminghandsetswithGSMisfarbetterthanCDMAhandsetsbecause

6、GSMisusedinmostthemarketsacrosstheglobe.Usersusingtri-bandorquad-bandcantraveltoEurope,IndiaandmostofAsiaandstillcanusetheircellphone・CDMAdoesnothavethismultibandcapability,thuscannotbeusedmultiplecountrieswithease.DifferencesbetweenCDMAandTDMA:CDMAtechnologyclaimsthat

7、itsbandwidthisthirteentimesefficientthanTDMAandfortytimesefficientthananalogsystems.CDMAalsohavebettersecurityandhigherdataandvoicetransmissionqualitybecauseofthespreadspectrumtechnologyituses,whichhasincreasedresistancetomultipathdistortion.ThebatterylifeishigherinTDM

8、AcomparedtoCDMAbecauseCDMAhandsetstransmitdataallthetimeandTDMAdoesnotrequireconstanttransmission.CDMAhasgreatercover