淺談關(guān)于移動通信發(fā)展趨勢外文翻譯

大連科技學(xué)院畢業(yè)設(shè)計(論文)外文翻譯學(xué)生姓名指導(dǎo)教師所在單位教研室主任 完成日期TalkaboutthedevelopmenttrendformobilecommunicationsOne，introduction:Mobilecommunicationmeansbetweenthemobileusers,ormobileusersandfixedcommunicationsbetween.，Withthedevelopmentofelectronictechnology,particularlysemiconductors,setsDevelopmentofcircuitandcomputertechnologyandmobilecommunicationshaveenjoyedrapiddevelopment.Withtheexpansionofitsapplicationfieldsandonimprovingtheperformancerequirements,allowmobilecommunicationintechnologyanddevelopmentofthetheorytoahigherlevel.Sinceinthe1980softhe20thcentury,themobilecommunicationshavebecomeindispensableinmoderncommunicationnetworkandoneofthefastestmeansofcommunication.Reviewingthedevelopmentofmobilecommunications,mobilecommunicationsdevelopmentthroughseveralstagesofdevelopment:thefirstmajorcellularmobilecommunicationtechnologyofanalogmobilecommunications,thetechnicalcharacteristicsofCellularnetworkstructureovercometheregionalcapacitylow,restrictedthescopeofactivitiesoftheproblem.SecondGisthecellularmobilecommunications,cellularsystemscanprovideintegratedservicedigitaltransmission,andotheradvantages.MainCharacteristicsofthirdGisinadditiontoprovidingsecondofmobilecommunicationsystemownadvantages,overcomeitsshortcomings,butcanalsoprovidebroadbandmultimediaservicecanprovidehigh-qualityvideomultimediaintegratedservices,andglobalroaming.Withmostofthemarenowsecondtechnology,thirdtechnologyisstillnotverysuccessful.buttherearealreadyfourthtechnologyvision.4Gstandardwithmorethanthirdofthefourthmobilecommunicationsystemfunction.。Two.4Gaboutmobilecfourththeconceptofmobilecommunicationtechnologiesasbroadbandaccessanddistributionnetwork,withasymmetryover2Mbitsdatatransmissioncapacity.Itconsistsoffixedbroadbandwirelessaccessandbroadbandwirelesslocalareanetwork,mobilebroadbandsystemandinteractivebroadcastingnetwork.fourthGstandardsthanthirdstandardhasmorefunctionality.Indifferentfixedfourthg,wirelessplatformsandwirelessservicesacrossdifferentfrequencybandnetwork,inanyplacewithbroadbandInternetaccess,includingsatellitecommunicationandstratosphericcommunicationtoprovideorientationoftime,dataacquisitionandremotecontrol,comprehensivefunctions.Inaddition,fourthmobilecommunicationsystemsareintegratedbroadbandmobilecommunicationsystemofmultifunctionalarebroadbandIPsystem.Currentlyindevelopmentandresearchof4Gcommunicationswillhavethefollowingcharacteristics：ommunicationsAcommunicationsfasterTheinitialstudyon4GcommunicationsisaimedatenhancingcellularphonesandotherwirelessaccesstheInternet,mobiledevicerate,so4Gcharacteristicsofcommunicationisitafasterspeedofwirelesscommunication.Expertsestimatedthatfourthmobilecommunicationssystemupto10-20Mbitsmaximumreach100Mbits.ThesecondnetworkspectrumwidthTomake4Gcommunicationtransmissionspeedofupto100Mbits,operatorsmustbeonthebasisof3Gcommunicationsnetworktocarryoutlarge-scaleimprovement,so4Gnetworkoncommunicationbandwidththan3Gnetworkbandwidthmuchhigher.Accordingtothestudy,each4Gchannelwillholdthe100MHzspectrum,equalto20timesoftheW-CDMA3Gnetwork.CompleteintegrationofthethreeservicesPersonalcommunications,informationsystems,broadcastingandentertainmentbusinessessuchasseamlessconnectionasawhole,meetthevariousneedsofusers.4Gshouldbeabletointegratedifferentmodelsofwirelesscommunicationto--fromindoorwirelesslocalareanetworkandBluetoothnetwork,cellularsignalandradioandtelevisiontosatellitecommunication,mobileuserstoroamfreelyfromastandardtoanotherstandard.Businessapplications,interconnectionbetweenvarioussystemplatformmoreconvenient,safe,andfordifferentusers,morepersonalized.4Gmobilephonefromthepointofviewoftheappearanceandstylewillhavemorebreakthroughscanthinkofis,spectaclesandwatches,cosmeticboxes,sneakersarelikelytobecome4Gterminal.FourintelligentpropertiesofevenhigherFourthMobileIntelligentbetter,notonlyexpressedinthedesignandoperationof4Gcommunicationterminalwithintelligent,butmoreimportantly4Gfunctionofcellphonecanimplementmanyunimaginable.Forexample,4Gmobilephoneswillbebasedontheenvironment,timeandotherfactorstotimelytoremindtheownerofthecellphone.Three,4Gaccesssysteminmobilecommunications4Gsystemformobilecommunicationaccessremarkablefeatureisthatintelligentmulti-modeterminalsmulti-modeterminalbasedoncommonplatform,throughavarietyoftechnology,invariousnetworksystemplatformrealizationofseamlessconnectionandcollaboration.In4Gmobilecommunications,basedonacommonplatformforallkindsofspecialaccesssystem,mutualcooperation,inthemostoptimalmannertomeetthecommunicationneedsofdifferentusers.Whenterminalaccessmulti-modelsystems,networkadaptiveallocationband,givetheoptimizationofroutinginordertoachievethebesteffectofcommunications.。Withthedevelopmentoftechnologyandchangesinmarketdemand,newtechnologywillconstantlyemerging.Differenttypesofaccesstechnologydesignedfordifferentbusiness.therefore,thebasisofouraccessapplicationfieldsoftechnology,smallmobileradiusandworkingenvironment,andtoaccesstechnologyforlayers.Distributionlayer:mainlybythestratosphericcommunications,satellitecommunicationandbroadcastingandTVcommunication,andthescopeofservicecoverage.Cellularlayer:mainlyby2G,3Gcommunicationsystems,servicescoveringlarger.HotcelllayerismainlycomposedofWLANnetworkservicestofocusonthecampus,communities,meetingcenter,mobilecommunicationabilityisverylimited.Personalnetworklayer:mainlyusedinthehome,Officeandotherplaces,theservicescopeofcoverageisverysmall.MobileCommunicationsLimitedability,butthroughInternetaccesssystemsofothernetworklayer.FixedNetwork:Doublestrands,coaxialcable,fibercompositionoffixedcommunicationsystem.Networkaccesssysteminaveryimportantpositionintheentiremobilenetworks.Toimprovenetworkperformance,accesssystemofhigh-levelagreementsandResearchNetworkself-optimizationandautomaticreconfigurationtechnologyanddynamicspectrumallocationandresourceallocationtechnology,networkmanagementandcooperationbetweendifferentaccesssystem.ImprovingandextendingtheapplicationofIPtechnologyinmobilenetwork,strengtheningthesoftwareradiotechnologyandoptimizationofradiotransmissiontechnologiessuchassupportingreal-timeandnon-real-timebusiness,seamlessconnectivityandnetworksecurity.Four,4GkeytechnologyofmobilecommunicationsystemApositioningtechnologyPositioningmobileterminallocationmethodformeasuringandcalculatingmethods.Itismainlybasedonmobileterminallocation,locationbasedonmobilenetworklocationormixedthreeways.4Gmobilecommunicationsystems,mobileterminalinmobilecommunicationbetweendifferentsystemplatforms.therefore,formobileterminallocationandtracking,istherealizationofmobileterminalinseamlessconnectionsbetweendifferentsystemplatformsandsystemsprerequisiteofhigh-speedandhigh-qualitymobilecommunicationsandprotection.ThesecondhandovertechnologySwitchtechnologyformobileterminalindifferentmobilecommunitybetweencommunicationbetweendifferentfrequenciesorsignaltoreducechannelselection,andsoon.SwitchTechnologyisthefutureofmobileterminalinmanyofthecommunicationsystem,mobilecommunitybetweensolidfoundationandanimportanttechnologyinmobilecommunications.Itismainlysoft-switchingandhardhandoff.4Gcommunicationsystem,switchingtechniqueismoreextensivescope,andinsoft-switchingandcombinationofhardhandoffdirectionofdevelopment.Threesoftwareradiotechnology4Gmobilecommunicationsystems,softwarewillbecomeverycomplicated.Tothisend,Theexpertssuggestedtheintroductionofsoftwareradiotechnology,asthemobilecommunicationstothirdfromsecond,andfourthbridgesinmobilecommunications.Softwareradiotechnologytocloseaspossibletotheprocessofdigitalanalogsignalantenna,ADandDAconvertersoonaspossibletoRFFront-EndusingDSPchannelseparation,modulationanddemodulationandchanneldecodingandsoon.Itaimstoestablishacommunicationplatform,platformsoftwaresystemtorealizemulti-channel,multi-levelandmulti-modewirelesscommunications.therefore,theapplicationofsoftwareradiotechnology,amobileterminalscanbeachievedbetweenthedifferentsystemsandplatforms,unimpeded.Therearemorematuresoftwareradiotechnologyparametercontrolsoftwareradiosystem.FoursmartantennatechnologySmartAntennawithinhibitionofsignalinterferenceandautomatictrackingandintelligencefeaturessuchasdigitalbeamadjustment,canmeetthedatacenter,mobileIPnetworkperformancerequirements.SmartAntennabeaminthespacefieldsuppressionofmutualinterferenceandtoenhancethespecialscopeofsignal,thistechnologycanimprovethequalityofsignalincreasetransmissioncapacity.FivemutualInterferencesuppressionandmultiuserdetectionDevelopmentofinteractiveInterferencesuppressionandmultiuserdetectiontechnologyshouldbecomepartofthe4G,theyuseinteractiveInterferencesuppressionmethodintroductiontothebasestationsandmobilephonesystem,eliminationofunnecessarynearbyandco-channeluserinteractioninterference,toensurethehighqualityofreceiversignalreception.Thiscombinationwillmeettheneedsofmoreusercapacity,butalsocanincreasethecoverage.MutualInterferencesuppressionandmultiuserdetectioncombinationoftwotechnologywillsignificantlyreducethedeploymentofnetworkinfrastructure,ensuretheimprovementofservicequality.SignalTransmissionandmodulationofsixnewtechnologyHigh-speedmobilecommunications,willfaceseverefrequencyselectionfadingfrequency-selectivefading.Toimprovethesignalperformance,researchanddevelopmentofintelligentmodulationanddemodulationtechniques,toeffectivelycurbthedecline.Forexample,theOrthogonalFrequencyDivisionMultiplexingOFDM,adaptiveequalizer.meanwhile,theTPC,RakeSpreadSpectrumreceive,hopping,FECsuchasAQRandTurbocodingtechnology,togetabettersignal-noiseratioofenergy.Five.conclusionsNowpeople,4Gcommunicationofthefuturelooksverymysterious,Manypeoplethinkthatthefourthwirelesscommunicationnetworksystemisthemostcomplextechnicalsysteminthehistoryofmankind.Allinall,smoothandcomprehensivelyimplement4Gcommunications,alsomayencountersomedifficulties.first,peopleinthefuture4Gcommunicationtransmissionspeedofthedemandwasthatitwillgreatlyimprove,theoreticallyhighestreaching100Mbits,buttherateofmobilephoneswillbelimitedbythecapacitycommunicationssystems.Accordingtoanalysisbyexpertsconcerned,4Gmobilephoneswillbedifficulttoachievethetheoryofspeed.secondly,4Gdevelopmentofthemarketwillfacegreatpressure.Someexpertspredictthat,after10years,2Gmultimediaserviceswillenterthirdstageofdevelopment,whichcovers3Gglobalnetworkhasbeenbasicallycompleted,morethan25oftheworld'spopulationuses3G,bythattime,thewholeindustryisabsorbingthirdtechnology,toaccept4Gtechnologyalsoneedsaprocessofgradualtransition.therefore,whentheconstructionof4Gcommunicationnetworksystem,carrierswillconsiderdirect3Gcommunicationsnetworkinfrastructure,withthegradualintroductionofthemethodtomakemobilecommunicationsfrom3Ggradualtransitionto4G.淺談關(guān)于移動通信發(fā)展趨勢引言

移動通信是指移動用戶之間，或移動用戶與固定用戶之間的通信。移動通信是指移動用戶之間，或移動用戶與固定用戶之間的通信。隨著電子技術(shù)的發(fā)展，特別是半導(dǎo)體、集

成電路和計算機(jī)技術(shù)的發(fā)展，移動通信得到了迅速的發(fā)展。隨著其應(yīng)用領(lǐng)域的擴(kuò)大和對性能要求的提高，促使移動通信在技術(shù)上和理論上向更高水平發(fā)展。20世紀(jì)80年代以來，移動通信已成為現(xiàn)代通信網(wǎng)中不可缺少并發(fā)展最快的通信方式之一。回顧移動通信的發(fā)展歷程，移動通信的發(fā)展大致經(jīng)歷了幾個發(fā)展階段：第一代移動通信技術(shù)主要指蜂窩式模擬移動通信，技術(shù)特征是蜂窩網(wǎng)絡(luò)結(jié)構(gòu)克服了大區(qū)制容量低、活動范圍受限的問題。第二代移動通信是蜂窩數(shù)字移動通信，使蜂窩系統(tǒng)具有數(shù)字傳輸所能提供的綜合業(yè)務(wù)等種種優(yōu)點。第三代移動通信的主要特征是除了能提供第二代移動通信系統(tǒng)所擁有的各種優(yōu)點，克服了其缺點外，還能夠提供寬帶多媒體業(yè)務(wù)，能提供高質(zhì)量的視頻寬帶多媒體綜合業(yè)務(wù)，并能實現(xiàn)全球漫游。現(xiàn)在用的大多是第二代技術(shù)，第三代技術(shù)還不太成功，但已有了第四代技術(shù)的設(shè)想。第四代移動通信系統(tǒng)（4G）標(biāo)準(zhǔn)比第三代具有更多的功能。

二、4G移動通信簡介

第四代移動通信技術(shù)的概念可稱為寬帶接入和分布網(wǎng)絡(luò)，具有非對稱的超過2Mbit/s的數(shù)據(jù)傳輸能力。它包括寬帶無線固定接入、寬帶無線局域網(wǎng)、移動寬帶系統(tǒng)和交互式廣播網(wǎng)絡(luò)。第四代移動通信標(biāo)準(zhǔn)比第三代標(biāo)準(zhǔn)擁有更多的功能。第四代移動通信可以在不同的固定、無線平臺和跨越不同的頻帶的網(wǎng)絡(luò)中提供無線服務(wù)，可以在任何地方用寬帶接入互聯(lián)網(wǎng)（包括衛(wèi)星通信和平流層通信），能夠提供定位定時、數(shù)據(jù)采集、遠(yuǎn)程控制等綜合功能。此外，第四代移動通信系統(tǒng)是集成多功能的寬帶移動通信系統(tǒng)，是寬帶接入IP系統(tǒng)。目前正在開發(fā)和研制中的4G通信將具有以下特征：（一）通信速度更快

由于人們研究4G通信的最初目的就是提高蜂窩電話和其他移動裝置無線訪問Internet的速率，因此4G通信的特征莫過于它具有更快的無線通信速度。專家預(yù)估，第四代移動通信系統(tǒng)的速度可達(dá)到10-20Mbit/s，最高可以達(dá)到100Mbit/s。

（二）網(wǎng)絡(luò)頻譜更寬

要想使4G通信達(dá)到100Mbit/s的傳輸速度，通信運營商必須在3G通信網(wǎng)絡(luò)的基礎(chǔ)上對其進(jìn)行大幅度的改造，以便使4G網(wǎng)絡(luò)在通信帶寬上比3G網(wǎng)絡(luò)的帶寬高出許多。據(jù)研究，每個4G信道將占有100MHz的頻譜，相當(dāng)于W-CDMA3G網(wǎng)絡(luò)的20倍。（三）多種業(yè)務(wù)的完整融合

個人通信、信息系統(tǒng)、廣播、娛樂等業(yè)務(wù)無縫連接為一個整體，滿足用戶的各種需求。4G應(yīng)能集成不同模式的無線通信——從無線局域網(wǎng)和藍(lán)牙等室內(nèi)網(wǎng)絡(luò)、蜂窩信號、廣播電視到衛(wèi)星通信，移動用戶可以自由地從一個標(biāo)準(zhǔn)漫游到另一個標(biāo)準(zhǔn)。各種業(yè)務(wù)應(yīng)用、各種系統(tǒng)平臺間的互聯(lián)更便捷、安全，面向不同用戶要求，更富有個性化。而且4G手機(jī)從外觀和式樣上看將有更驚人的突破，可以想象的是，眼鏡、手表、化妝盒、旅游鞋都有可能成為4G終端。

（四）智能性能更高

第四代移動通信的智能性更高，不僅表現(xiàn)在4G通信的終端設(shè)備的設(shè)計和操作具有智能化，更重要的是4G手機(jī)可以實現(xiàn)許多難以想象的功能。例如，4G手機(jī)將能根據(jù)環(huán)境、時間以及其他因素來適時提醒手機(jī)的主人。三、4G移動通信的接入系統(tǒng)

4G移動通信接入系統(tǒng)的顯著特點是，智能化多模式終端（multi-modeterminal）基于公共平臺，通過各種接技術(shù)，在各種網(wǎng)絡(luò)系統(tǒng)（平臺）之間實現(xiàn)無縫連接和協(xié)作。在4G移動通信中，各種專門的接入系統(tǒng)都基于一個公共平臺，相互協(xié)作，以最優(yōu)化的方式工作，來滿足不同用戶的通信需求。當(dāng)多模式終端接入系統(tǒng)時，網(wǎng)絡(luò)會自適應(yīng)分配頻帶、給出最優(yōu)化路由，以達(dá)到最佳通信效果。目前，4G移動通信的主要接入技術(shù)有：無線蜂窩移動通信系統(tǒng)（例如2G、3G）；無繩系統(tǒng)（如DECT）；短距離連接系統(tǒng)（如藍(lán)牙）；WLAN系統(tǒng)；固定無線接入系統(tǒng)；衛(wèi)星系統(tǒng)；平流層通信（STS）；廣播電視接入系統(tǒng)（如DAB、DVB-T、CATV）。隨著技術(shù)發(fā)展和市場需求變化，新的接入技術(shù)將不斷出現(xiàn)。

不同類型的接入技術(shù)針對不同業(yè)務(wù)而設(shè)計，因此，我們根據(jù)接入技術(shù)的適用領(lǐng)域、移動小區(qū)半徑和工作環(huán)境，對接入技術(shù)進(jìn)行分層。

分配層：主要由平流層通信、衛(wèi)星通信和廣播電視通信組成，服務(wù)范圍覆蓋面積大。

蜂窩層：主要由2G、3G通信系統(tǒng)組成，服務(wù)范圍覆蓋面積較大。

熱點小區(qū)層：主要由WLAN網(wǎng)絡(luò)組成，服務(wù)范圍集中在校園、社區(qū)、會議中心等，移動通信能力很有限。

個人網(wǎng)絡(luò)層：主要應(yīng)用于家庭、辦公室等場所，服務(wù)范圍覆蓋面積很小。移動通信能力有限，但可通過網(wǎng)絡(luò)接入系統(tǒng)連接其他網(wǎng)絡(luò)層。

固定網(wǎng)絡(luò)層：主要指雙絞線、同軸電纜、光纖組成的固定通信系統(tǒng)。

網(wǎng)絡(luò)接入系統(tǒng)在整個移動網(wǎng)絡(luò)中處于十分重要的位置。未來的接入系統(tǒng)將主要在以下三個方面進(jìn)行技術(shù)革新和突破：為最大限度開發(fā)利用有限的頻率資源，在接入系統(tǒng)的物理層，優(yōu)化調(diào)制、信道編碼和信號傳輸技術(shù)，提高信號處理算法、信號檢測和數(shù)據(jù)壓縮技術(shù)，并在頻譜共享和新型天線方面做進(jìn)一步研究。為提高網(wǎng)絡(luò)性能，在接入系統(tǒng)的高層協(xié)議方面，研究網(wǎng)絡(luò)自我優(yōu)化