3桂电毕设英文翻译原文.docx

3桂电毕设英文翻译原文.docx

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3桂电毕设英文翻译原文

毕业设计（论文）英文翻译原文

院（系）：

桂林航天工业高等专科学校

专业：

计算机通信工程

学生姓名：

胡文凯

学号：

030111301497

指导教师：

嵇建波

职称：

副教授

2012年4月15日

Chapter1Modernmobilecommunicationtechnology

Innowhighlytheinformationizationsociety,theinformationandthecorrespondencehavebecomethemodernsociety“thelife”.Theinformationexchangemainlyreliesonthecomputercorrespondence,butcorrespondstakesthetransmissionmethod,withthesensingtechnology,thecomputertechnologyfusesmutually,hasbecomeinthe21stcenturytheinternationalsocietyandtheworldeconomicdevelopmentpowerfulengine.Inordertoofadaptthetimerequest,thenewgenerationofmobilecommunicationtechnologyseasonableandlives,thenewgenerationofmobilecommunicationtechnologyisthepeoplesaidthatthirdgeneration'scorecharacteristicisthewidebandaddressingturnsonnon-gaproamingbetweentherigidnetworkandnumerousdifferentcommunicationssystem's,gainsthemultimediacommunicationservices.

Alongwiththetimeprogress,thetechnicalinnovation,people'sliferequest'senhancement,themobilecommunicationtechnologyrenewalspeedisquiteastonishing,almosteveryothertenyearmobilecommunicationtechnologyhasatransformationupdate,fromthe1980s“themobilephone”topresent's3Ghandset,duringhashadtwomobilecommunicationtechnologytransformation,transitsfrom1GAMPSto2GGSM,fromGSMtoIMT-2000（i.e.3Gtechnology）.Knowsmodernonmethemobilecommunicationtechnologytohavethefollowingseveralaspectimportanttechnology:

1.widebandmodulationandmultipleaccesstechnique

Thewirelesshighspeeddatatransmissioncannotonlydependonthefrequencyspectrumconstantlytheexpansion,shouldbehigherthanthepresentnumbermagnitudeatleastinthefrequencyspectrumefficiency,mayusethreetechnologiesinthephysicallevel,namelyOFDM,UWBandfreetimemodulationcode.OFDMwithotherencodingmethod'sunion,nimblyOFDMandTDMA,FDMA,CDMA,SDMAcombinesthemultipleaccesstechnique.

Inthe1960stheOFDMmulti-channeldatatransmissionhassucceededusesinKineplexandtheKathrynhighfrequencymilitarychannels.OFDMhasusedin1.6Mbit/shighbitratedigitalsubscriberline（HDSL）,6Mbit/sasymmetricaldigitalsubscriberline（ADSL）,100Mbit/sreallyhighspeedfiguresubscriber'sline（VDSL）,digitalaudiofrequencybroadcastanddigitalvideobroadcastandsoon.OFDMapplieson5GHzprovides54Mbit/swirelesslocalnetworkIEEE802.11aandIEEE802.11g,highperformancethisregionnetworkHiperLAN/2andETSI-BRAN,butalsotakesmetropolitanareanetworkIEEE802.16andtheintegratedservicedigitbroadcast（ISDB-T）thestandard.Compareswiththesingleloadfrequencymodulationsystemservicepattern,theOFDMmodulationservicepatternneedstosolvetherelativelybigpeakevenpowerratio（PAPR,PeaktoAveragePowerRatio）andtothefrequencyshiftingandthephasenoisesensitivequestion.

Highspeedmobilecommunication'sanotherrequestisunderthewidenoisebandwidth,mustdemodulatethesignal-to-noiseratiotoreduceasfaraspossible,thusincreasesthecoverarea.Mayadopttheanti-fadingthefullstartpowercontrolandthepilotfrequencyauxiliaryfasttrackdemodulationtechnology,likethefrequencyrangeanti-fading'sRakereceiveandthetracktechnology,theOFDMAtechnologywhichdeclinesfromthetimedomainandthefrequencyrangeresistancetimeandthefrequencyselectivity,thelinkauto-adaptedtechnology,theunioncodingtechnique.

2.frequencyspectrumusefactorlifttechnique

Thefundamentalresearchpointedout:

IntheindependentRayleighscatteringchannel,thedatarateandtheantennaseveraltenthlinearrelationships,thecapacitymayreachShannon90%.Islaunchingandthereceivingendmayobtainthecapacityandthefrequencyspectrumefficiencygainbythemulti-antennadevelopmentchannelspace.TheMIMOtechnologymainlyincludesthespatialmultiplyingandthespacediversitytechnology,concurrentorthesalvosameinformationenhancesthetransmissionreliabilityontheindependentchannel.

Receivesanddispatchesthebilateralspacediversityisthehigh-capacitywirelesscommunicationsystemusesoneoftechnical.BellLabfreetime'soppositeangleBLAST（D-BLAST）capacityincreasetoreceiveanddispatchthebilateralsmallestantennanumberinadministrativelevelsthefunction.ThecrosstimedomainwhichandtheairzoneexpansionsignalconstitutesusingMIMOmayalsoresistthemulti-diameterdisturbance.V-BLASTsystemwhenindoor24~34dB,thefrequencyspectrumusefactoris20~40bit/s/Hz.Butlaunchesandthereceivingenduses16antennas,when30dB,thefrequencyspectrumusefactorincreasesto60~70bit/s/Hz.

Thesmartantennaautomatictrackingneedsthesignalandtheauto-adaptedfreetimeprocessingalgorithm,producesthedimensionalorientationwavebeamusingtheantennaarray,causesthemainwavebeamalignmentsubscribersignaldirectionofarrivalthroughthedigitalsignalprocessingtechnology,thesidelobeorzerofallsthealignmentunwantedsignaldirectionofarrival.Theauto-adaptedarrayantennas（AAA,AdaptiveArrayAntennas）disturbsthecounter-balancebalancer（ICE,InterferenceCancelingEqualizer）tobepossibletoreducedisturbsandcutstheemissivepower.

3.softwareradiotechnology

Thesoftwareradiotechnologyisinthehardwareplatformthroughthesoftwareeditionbyaterminalimplementationdifferentsysteminmanykindsofcommunicationservices.Itusesthedigitalsignalprocessinglanguagedescriptiontelecommunicationpart,downloadsthedigitalsignalprocessinghardwarebythesoftwareroutine（DSPH,DigitalSignalPocessingHardware）.Byhasthegeneralopeningwirelessstructure（OWA,OpenWirelessArchitecture）,compatiblemanykindsofpatternsbetweenmanykindsoftechnicalstandardsseamlesscut.

UWBisalsocalledthepulsetoberadio,themodulationusesthepulsewidthinthenanosecondlevelfastriseandthedroppulse,thepulsecoverfrequencyspectrumfromthecocurrenttotheluckyhertz,doesnotneedintheradiofrequencywhichtheconventionnarrowbandfrequencymodulationneedstotransform,afterpulseformation,maydeliverdirectlytotheantennalaunch.

4.networksecurityandQoS

QoSdividesintowirelessandthewiredsidetwoparts,wirelessside'sQoSinvolvestheradioresourcemanagementandthedispatch,theadmissioncontrolandthemobilitymanagementandsoon,themobilitymanagementmainlyincludestheterminalmobility,individualmobilityandservicemobility.Wiredside'sQoSinvolvesbasedontheIPdiffSerdiscriminationserviceandtheRSVPend-to-endresourcesreservationmechanism.MechanismmapsthewirelesssideIPdiffSerIPtheQoS.Networksecurityincludingnetworkturningonsecurity,corenetworksecurity,applicationsecurity,safetymechanismvisibilityandconfigurable.

Intheabovemodernmobilecommunicationkeytechnologies'sfoundation,hashadthelandhoneycombmobilecommunication,thesatellitecommunicationaswellasthewirelessInternetcommunication,thesemailingaddresscausedthecorrespondenceappearancetohavethehugechange,usedthedigitaltechniquethemodernwirelesscommunicationalreadytopermeatethenationaleconomyeachdomainandpeople'sdailylife,forthisreason,weneededtocarethatitstrendofdevelopment,hopeditdevelopedtowardmoreandmoreconvenientpeople'slife'sdirection,willletnowushavealookatthemodernmobilecommunicationthefuturetrendofdevelopment.

modernmobilecommunicationtechnologicaldevelopmentsevennewtendencies:

First,mobilitymanagementalreadyfromterminalmanagementtoindividualmanagementandintelligentmanagementdevelopment

Second,networkalreadyfromsynchronizeddigitalcircuittoasynchronousdigitalgroupingandasynchronoustransfermode（ATM）development;

third,software'sdevelopmentsactuatedfromthealgorithmtotheprocedure-orientedandfacethegoaltendencydevelopment;

fouth,informationprocessinghavedevelopedfromthevoicetothedataandtheimage;

fifth,wirelessfrequencyspectrumprocessingalreadyfromnarrowbandsimulationtothenarrowbandCDMAdevelopment;

sixth,computershavedevelopedfromcentralprocessingtothedistributionalserverandintellectualizedprocessing;

seventh,semiconductordeviceshavedevelopedfromeachchip16,000,000,000,000/150MHzspeedVLSIto0.5/350MHzspeedVLSIand2,000,000,000,000,000/550MHzspeedVLSI.

Underthistendency'sguidance,themobileservicerapiddevelopment,itsatisfiedthepeopleinanytime,anyplacetocarryonthecorrespondencewithanyindividualthedesire.Themobilecommunicationrealizesinthefuturetheidealperson-to-personcommunicationservicewaythatmustbetaken.Intheinformationsupporttechnology,themarketcompetitionandunderthedemandcombinedaction,themobilecommunicationtechnology'sdevelopmentisprogressesbyleapsandbounds,presentsthefollowingseveralgeneraltrends:

1）networkservicedigitization,grouping;

2）networkingwideband;3）networkingintellectualization;

4）higherfrequencyband;

5）moreeffectiveusefrequency;

6）eachkindofnetworktendsthefusion.

Theunderstanding,graspsthesetendencieshasthevitalpracticalsignificancetothemobilecommunicationoperatorandtheequipmentmanufacturer.

Chapter2CellularWirlessCommunicationSystem

Cellularcommunicationsystemsallowalargenumberofmobileuserstoseamlesslyandsimultaneouslycommunicatetowirelessmodemsatfixedbasestationsusingalimitedamountofradiofrequency（RF）spectrum.TheRFtransmissionsreceivedatthebasestationsfromeachmobilearetranslatedtobaseband,ortoawidebandmicrowavelin