四G網(wǎng)絡(luò)技術(shù)外文翻譯

外文資料翻譯

DiscussionontheDevelopmentTrendofMobileCommunications

IIntroduction:

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.

II.4Gaboutmobilecommunication

fourththeconceptofmobilecommunicationtechnologiesasbroadbandaccessanddistributionnetwork,withasymmetryover2Mbitsdatatransmissioncapacity.Itconsistsoffixedbroadbandwirelessaccessandbroadbandwirelesslocalareanetwork,mobilebroadbandsystemandinteractivebroadcastingnetwork.fourthGstandardsthanthirdstandardhasmorefunctionality.Indifferentfixedfourthg,wirelessplatformsandwirelessservicesacrossdifferentfrequencybandnetwork,inanyplacewithbroadbandInternetaccess,includingsatellitecommunicationandstratosphericcommunicationtoprovideorientationoftime,dataacquisitionandremotecontrol,comprehensivefunctions.Inaddition,fourthmobilecommunicationsystemsareintegratedbroadbandmobilecommunicationsystemofmultifunctionalarebroadbandIPsystem.Currentlyindevelopmentandresearchof4Gcommunicationswillhavethefollowingcharacteristics：

(A)communicationsfaster

Theinitialstudyon4GcommunicationsisaimedatenhancingcellularphonesandotherwirelessaccesstheInternet,mobiledevicerate,so4Gcharacteristicsofcommunicationisitafasterspeedofwirelesscommunication.Expertsestimatedthatfourthmobilecommunicationssystemupto10-20Mbitsmaximumreach100Mbits.

(B)networkspectrumwidth

Tomake4Gcommunicationtransmissionspeedofupto100Mbits,operatorsmustbeonthebasisof3Gcommunicationsnetworktocarryoutlarge-scaleimprovement,so4Gnetworkoncommunicationbandwidththan3Gnetworkbandwidthmuchhigher.Accordingtothestudy,each4Gchannelwillholdthe100MHzspectrum,equalto20timesoftheW-CDMA3Gnetwork.

(C)Completeintegrationofthethreeservices

Personalcommunications,informationsystems,broadcastingandentertainmentbusinessessuchasseamlessconnectionasawhole,meetthevariousneedsofusers.4Gshouldbeabletointegratedifferentmodelsofwirelesscommunicationto--fromindoorwirelesslocalareanetworkandBluetoothnetwork,cellularsignalandradioandtelevisiontosatellitecommunication,mobileuserstoroamfreelyfromastandardtoanotherstandard.Businessapplications,interconnectionbetweenvarioussystemplatformmoreconvenient,safe,andfordifferentusers,morepersonalized.4Gmobilephonefromthepointofviewoftheappearanceandstylewillhavemorebreakthroughscanthinkofis,spectaclesandwatches,cosmeticboxes,sneakersarelikelytobecome4Gterminal.

(D)intelligentpropertiesofevenhigher

FourthMobileIntelligentbetter,notonlyexpressedinthedesignandoperationof4Gcommunicationterminalwithintelligent,butmoreimportantly4Gfunctionofcellphonecanimplementmanyunimaginable.Forexample,4Gmobilephoneswillbebasedontheenvironment,timeandotherfactorstotimelytoremindtheownerofthecellphone.

III,4Gaccesssysteminmobilecommunications

4Gsystemformobilecommunicationaccessremarkablefeatureisthatintelligentmulti-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.

IV,4Gkeytechnologyofmobilecommunicationsystem

ApositioningtechnologyPositioningmobileterminallocationmethodformeasuringandcalculatingmethods.Itismainlybasedonmobileterminallocation,locationbasedonmobilenetworklocationormixedthreeways.4Gmobilecommunicationsystems,mobileterminalinmobilecommunicationbetweendifferentsystemplatforms.therefore,formobileterminallocationandtracking,istherealizationofmobileterminalinseamlessconnectionsbetweendifferentsystemplatformsandsystemsprerequisiteofhigh-speedandhigh-qualitymobilecommunicationsandprotection.

Switchtechnologyformobileterminalindifferentmobilecommunitybetweencommunicationbetweendifferentfrequenciesorsignaltoreducechannelselection,andsoon.SwitchTechnologyisthefutureofmobileterminalinmanyofthecommunicationsystem,mobilecommunitybetweensolidfoundationandanimportanttechnologyinmobilecommunications.Itismainlysoftswitchingandhardhandoff.4Gcommunicationsystem,switchingtechniqueismoreextensivescope,andinsoft-switchingandcombinationofhardhandoffdirectionofdevelopment.Threesoftwareradiotechnology4Gmobilecommunicationsystems,softwarewillbecomeverycomplicated.Tothisend,Theexpertssuggestedtheintroductionofsoftwareradiotechnology,asthemobilecommunicationstothirdfromsecond,andfourthbridgesinmobilecommunications.Softwareradiotechnologytocloseaspossibletotheprocessofdigitalanalogsignalantenna,ADandDAconvertersoonaspossibletoRFFront-EndusingDSPchannelseparation,modulationanddemodulationandchanneldecodingandsoon.Itaimstoestablishacommunicationplatform,platformsoftwaresystemtorealizemulti-channel,multi-levelandmulti-modewirelesscommunications.Therefore,theapplicationofsoftwareradiotechnology,mobileterminalscanbeachievedbetweenthedifferentsystemsandplatforms,unimpeded.Therearemorematuresoftwareradiotechnologyparametercontrolsoftwareradiosystems.SmartAntennawithinhibitionofsignalinterferenceandautomatictrackingandintelligencefeaturessuchasdigitalbeamadjustment,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.

V.Conclusions

Nowpeople,4Gcommunicationofthefuturelooksverymysterious,Manypeoplethinkthatthefourthwireless