通信專業(yè)英語期末復(fù)習(xí)

廈門工學(xué)院14級通信工程專業(yè)英語復(fù)習(xí)整理-6-Unit１【中譯英】信號:signal(2)波特率:thebaudrate(3)單工:simplex(4)同步:synchronous(5)信道:communicationschannel(6)模擬:analog(7)數(shù)字:digital(8)電磁的:electromagnetic(9)串行口:serialport(10)帶寬:bandwidth【英譯中】baud:波特(2)asynchronous:異步的(3)fullduplex:全雙工(4)parallel:并行(5)electromagnetic:電磁的(6)discrete:離散的(7)simultaneously:同時發(fā)生地(8)parity:奇偶校驗【句子翻譯（英譯中）】Sincetransmitteddatacanbeassignedtodifferentfrequencies,thewiderthebandwidth,themorethefrequencies,andthemoredatacanbetransmittedatthesametime.因為傳輸?shù)臄?shù)據(jù)能被分配到不同頻率，所以帶寬越寬頻率越多，同一時間能被傳輸?shù)臄?shù)據(jù)就越多。Todistinguishwhereonecharacterstopsandanotherstarts,theasynchronouscommunicationmodeusesastartandastopbit.為了辨別一個字符在什么地方結(jié)束而另一個字符在什么地方開始，異步通信模式使用一個起始位和一個結(jié)束位。MoretechnicalmanesfortheserialportareRS-232Cconnectorandasynchronouscommunicationport.串行端口技術(shù)上又叫做RS-232C連接器和異步通信接口?！径温浞g（英譯中）】Thethirdisthetransmissionmode.Transmissionmodesincludetheasynchronousmodeandthesynchronousmode.Intheasynchronoustransmissionmode,individualcharacters(madeupofbits)aretransmittedatirregularintervals,forexample.Whenauserentersdata.Todistinguishwhereonecharacterstopsandanotherstarts,theasynchronouscommunicationmodeusesastartandastopbit.Anadditionalbitcalledaparitybitissometimesincludedattheendofeachcharacter.Paritybitsareusedforerrorchecking.Theasynchronoustransmissionmodeisusedforlowerspeeddatatransmissionandisusedwithmostcommunicationequipmentdesignedforpersonalcomputers.第三是傳輸模式。傳輸模式包括異步和同步。在異步傳輸模式中，單獨的字符(由比特組成)以不規(guī)則的時間間隔傳輸，例如當(dāng)用戶輸入數(shù)據(jù)時。為了辨別一個字符在什么地方停止而另一個字符在什么地方開始，異步通信模式使用一個起始位和一個停止位。一個稱為奇偶位的附加位有時包含在每個字符的末端。奇偶位用于錯誤校驗。異步傳輸模式用于低速數(shù)據(jù)傳輸以及用在設(shè)計適合個人計算機(jī)的大多數(shù)的通信設(shè)備中。[第一段翻譯]Theneedtocommunicateispartofman’snature.Sincethebeginningoftimemanhasuseddifferenttechniquesandmethodstocommunicate.Circumstancesandavailabletechnologyhavedictatedthemethodandmeansofcommunications.Datecommunicationconcernsitselfwiththetransmission(sendingandreceiving)ofinformationbetweentwoparties.Nowlet’slearnthefoundationknowledgeofdatacommunication.通信是人類固有需求的一部分，人類一開始就使用不同的技術(shù)和方式進(jìn)行交流，而環(huán)境和可利用的技術(shù)也限定了人類通信的方法和方式。數(shù)據(jù)通信涉及在通信雙方間傳遞信息?，F(xiàn)在我們共同來學(xué)習(xí)關(guān)于數(shù)據(jù)通信的基本知識。Unit3【中譯英】（1）載波：CarrierFrequencies（2）多路復(fù)用：Multiplexing（3）載波振蕩頻率：thefrequencyatwhichthestation’scarrieroscillates（4）頻分復(fù)用：FrequencyDivisionMultiplexing（5）旋轉(zhuǎn)開關(guān)：round-robinscheme（6）時分復(fù)用：TimeDivisionMultiplexing【縮寫翻譯】FDM：FrequencyDivisionMultiplexing頻分復(fù)用TDM：TimeDivisionMultiplexing時分復(fù)用【句子翻譯（英譯中）】Infact，achannelnumberismerelyshorthandforthefrequencyatwhichthestation’scarrieroscillates.實際上，頻道號碼就是電視臺載波用的振蕩頻率的速記。Areceiverconfiguredtoacceptacarrieratagivenfrequencywillnotbeaffectedbysignalsentatotherfrequencies.一個接收器被設(shè)置成接收給定頻率的載波，它將不會受其他頻率信號的影響（或干擾）。FrequencyDivisionMultiplexing(FDM)isthetechnicaltermappliedtoanetworksystemthatusesmultiplecarrierfrequenciestoallowindependentsignalstotravelthroughamedium.頻分復(fù)用（FDM）是使用多個載波頻率在一個介質(zhì)中同時傳輸多個獨立信號的計算機(jī)網(wǎng)絡(luò)系統(tǒng)術(shù)語。Inpractice,however,twocarriersoperatingatalmostthesamefrequencyoratexactmultiplesofafrequencycaninterferewithoneanother.實際上，兩個頻率相近或頻率成整數(shù)倍的載波會彼此干擾。ThemandateforlargegapebetweenthefrequenciesassignedtocarriersmeansthatunderlyinghardwareusedwithFDMcantolerateawiderangeoffrequencies.在各載波的頻率之間的大間隔意味著FDM所用的硬件能容納很寬的頻率范圍。ThegeneralalternativetoFDMistimedivisionmultiplexing(TDM),inwhichsourcessharingamediumtaketurns.與FDM不同的另一種復(fù)用形式是時分多路復(fù)用（TDM），按這種方式各發(fā)送源輪流使用共享的通信介質(zhì)?！径温浞g（英譯中）】Dividingdataintosmallpacketsensuresthatallsourcesreceivepromptservicebecauseitprohibitsonesourcefromgainingexclusiveaccessforanarbitrarilylongtime.Inparticular,ifonesourcehasafewpacketstosendandtheotherhasmany,allowingbothsourcestotaketurnssendingpacketswhichguaranteesthatthesourcewithasmallamountofdatawillfinishpromptly.將數(shù)據(jù)分成小包以確保所有的信源都能得到及時服務(wù)，因為這時是禁止一個信源獲取一個獨占的長時服務(wù)。尤其是，如果一個信源需要發(fā)送的數(shù)據(jù)包數(shù)量較少，而另一個信源需要發(fā)送的數(shù)據(jù)包較多時，采用時間片輪轉(zhuǎn)方式使兩個信源輪流發(fā)送數(shù)據(jù)包以確保數(shù)據(jù)包較少的信源的數(shù)據(jù)發(fā)送能及時完成。[第一段翻譯]Computernetworksthatuseamodulatedcarrierwavetotransmitdataaresimilartotelevisionstationsthatusedamodulatedcarrierwavetobroadcastvideo.Thesimilaritiesprovidetheintuitionneededtounderstandafundamentalprinciple:Twoormoresignalsthatusedifferentcarrierfrequenciescanbetransmittedoverasinglemediumsimultaneouslywithoutinterference.計算機(jī)網(wǎng)絡(luò)使用調(diào)制載波傳輸數(shù)據(jù)與電視臺使用載波廣播視頻的方式很類似。這種相似性是理解一個基本原理所必需的直覺。使用不同的載波頻率可以在一個傳輸媒介上傳送不互相干擾的兩個或更多的信號。Unit4【中譯英】電磁波:Electromagneticwave(2)同軸電纜:Coaxialcable(3)雙絞線:twisted-pairwire微波系統(tǒng):Microwavesystem(5)同步衛(wèi)星:Satellitesystem(6)無線電波飽和度:thesaturationoftheairwaves【英譯中】unsheathed:無覆蓋的(2)insulator:絕緣體(3)susceptible:易受影響的(4)vicinity:鄰近地區(qū)(5)curvature:曲度antenna:天線(7)gigahertz:千兆赫(8)nonconductive:不傳導(dǎo)的【句子翻譯（英譯中）】Theformormethodofcommunicationsaffectsthemaximumrateatwhichdatacanbemovedthroughthechannelandthelevelofnoisethatwillexist...通信的形式或方法決定著數(shù)據(jù)可以通過信道傳輸?shù)淖畲笏俣纫约皶霈F(xiàn)的噪聲等級Obviously，somesituationsrequirethatdatabemovedasfastaspossible,othersdon’t.顯然，有時要求數(shù)據(jù)傳輸?shù)迷娇煸胶?，有時則不然。Understandinghowthesemediafunctionwillhelpyousortoutthevariousratesandchargesforthemanddeterminewhichisthemostappropriateinagivensituation.理解這些媒介的性能將幫助你區(qū)別不同的速率和費用并決定在一個特定的情況下哪一種是最適合的。...whichlimitsthepracticaldistancethatdatacanbetransmittedwithoutbeinggarbled這限制了數(shù)據(jù)不失真?zhèn)鬏數(shù)膶嶋H距離。Tobereceivedintact,digitalsignalsmustbe“refreshed”everyonetotwomilesthroughtheuseofanamplifierandrelatedcircuits,whichtogetherarecalledrepeaters.數(shù)字信號想要完整接收，必須每1~2英里用放大器及相關(guān)電路重新放大，這種放大裝置稱為增音器。Thedistancebetweenthetowersdependsonthecurvatureofthesurfaceterraininthevicinity.兩座塔之間的距離取決于附近地表的彎曲程度。Eachtowerfacilityreceivesincomingtraffic,bootsthesignalstrength,andsendsthesignaltothenextstation.每個塔上的設(shè)備接收過來的信號，加以放大，并把信號發(fā)送到下一個基站。However.Thesaturationoftheairwaveswithmicrowavetransmissionshasreachedthepointwherefutureneedswillhavetobesatisfiedbyothercommunicationsmethods,suchasfiberopticcablesorsatellitesystems.但是，當(dāng)傳輸微波的空氣波達(dá)到飽和狀態(tài)時，必須要有其他方式來滿足將來的需要，例如光纖和衛(wèi)星系統(tǒng)。【段落翻譯（英譯中）】Insteadofusingwireorcables,microwavesystemscanusetheatmosphereasthemediumthroughwhichtotransmitsignals.Thesesystemsareextensivelyusedforhigh-volumeaswellaslong-distancecommunicationofbothdataandvoiceintheformofelectromagneticwavessimilartoradiowavesbutinahigherfrequencyrange.Microwavesignalsareoftenreferredtoas“l(fā)ineofsight”signalsbecausetheycannotbendaroundthecurvatureoftheearth.Instead,theymustberelayedfrompointtopointbymicrowavetowers,orrelaystations,placed20to30milesapart.Thedistancebetweenthetowersdependsonthecurvatureofthesurfaceterraininthevicinity.Thesurfaceoftheearthtypicallycurvesabout8incheseverymile.Thetowershaveeitheradishorahorn-shapedantenna.Thesizeoftheantennavariesaccordingtothedistancesignalsmustcover.Along-distanceantennacouldeasilybe10feetorlargerinsizeandadishof2to4feetindiameter,whichyouoftenseeoncitybuildings,islargeenoughforsmalldistances.Eachtowerfacilityreceivesincomingtraffic,bootsthesignalstrength,andsendsthesignaltothenextstation.和用導(dǎo)線及電纜不同，微波系統(tǒng)用大氣作為媒介，據(jù)此傳輸信號。這些系統(tǒng)主要用于大批量及長距離的數(shù)據(jù)和話音通信，類似于無線電波，但頻率范圍更高。微波信號通常是直線信號，因為它們不能隨地球的彎曲而彎曲；相反，它們必須由微波塔或每20～30英里設(shè)置的中繼站實現(xiàn)點到點的轉(zhuǎn)發(fā)。兩座塔之間的距離取決于附近地表的彎曲程度。地球表面一般說來每英里彎曲8英寸。微波塔有一個截拋物面天線或一個圓錐形天線。天線的長度隨信號需要覆蓋的范圍而變化。一個長距離天線可達(dá)10英尺或更長；直徑在2-4英尺的截拋物面天線對于短距離的轉(zhuǎn)發(fā)也就足夠了，這種天線在城市建筑物頂上能經(jīng)?？吹?。每個塔上的設(shè)備接收過來的信號，加以放大，并把信號發(fā)送到下一個基站。[第一段翻譯]Togofromheretothere,datemustmovethroughsomething.Atelephoneline,acable,ortheatmospherearealltransmissionmedia,orchannels.Butbeforethedatacanbecommunicated,itmustbeconvertedintoaformsuitableforcommunication.Thethreebasicformsintowhichdatacanbeconvertedforcommunicationare:(1):Electricalpulsesorcharges(usedtotransmitvoiceanddataovertelephonelines)(2):Electromagneticwaves(similartoradiowaves)(3):Pulsesoflight數(shù)據(jù)必須通過某種東西，才能由此及彼。一條電話線，一根電纜，或空氣都可稱為傳輸媒介或信道。但是，在數(shù)據(jù)傳輸之前，必須轉(zhuǎn)化為適合通信的形式?？梢赞D(zhuǎn)化為適合通信的三種基本數(shù)據(jù)形式是:1.電脈沖和電荷(用于通過電話線傳送聲音和數(shù)據(jù))2.電磁波(類似于無線電波)3.光脈沖Unit7【中譯英】光纖：Fiberoptic(2)光脈沖：Thepulsesoflight(3)單模光纖：singlemodeOpticalFiber多模光纖：multimodeOpticalFiber(5)塑料光纖：PlasticOpticalFiber(POF)【句子翻譯（英譯中）】(1)Afiberlookslikeacommonglasscylinderconsistingofcoreandcladdingregions.光纖看上去像一普通玻璃圓柱體，由纖芯和包層組成。Asinglemodecableismadeupofoneoranumberofquartzfiberswithadiameterof8.3μmto10μmthathasonemodeoftransmission.單模光纜由直徑為8.3微米至10微米的一條或若干條光線組成，并且只以一種模式進(jìn)行傳輸Thestepindexmultimodewasthefirstfiberdesignedbutistooslowformostuses,duetothedispersioncausedbythedifferentpathlengthsofthevariousmodes.階躍型多模光纖是首先光線產(chǎn)品，但由于存在多個不同路徑長度引起的模式色散從而使得它在大多數(shù)的使用中傳輸速率太低。Thegradedindexmultimodefiber,asthenameimplies,therefractiveindexofthisfibergraduallydecreasesfromthecoreoutthroughthecladdingtocompensateforthedifferentpathlengthsofthemodes.漸變型多模光纖正如其名，它的折射率從纖芯到包層逐漸減小，以彌補(bǔ)不同路徑長度造車你給的模式色散?！径温浞g（英譯中）】Bycontrast,amultimodefiberhasacorediameterthatismuchlargethanthewavelengthoflighttransmitted.(Themostcommonsizeis62.5μm).Lightwavesaredispersedintonumerouspaths,ormodes,astheytravelthroughthecable’scoretypically850nmor1300nm.However,inlongcableruns(greaterthan3000m),multiplepathsoflightcancausesignaldistortionatthereceivingend,resultinginanunclearandincompletedatatransmission.與單模光纖相反，多模光纖的纖芯直徑遠(yuǎn)大于傳輸光波的波長(常用的芯徑為62．5gm)。光波在光纜纖芯中傳輸時的典型波長為850nm或1300nm并被分散成眾多的路徑和模式。然而，在長距離光纜(超過3000m)傳輸時，多個路徑的光波會在接收端造成信號扭曲、失真，并導(dǎo)致傳輸數(shù)據(jù)的不清晰和不完整。[第一段翻譯]Althoughsatellitesystemsareexpectedtobethedominantcommunicationmediumforlongdistancesduringthisdecade,fiberopticstechnologyisexpectedtorevolutionizethecommunicationsindustrybecauseofitslowcost,hightransmissionvolume,lowarrogate,andmessagesecurity.Fiberopticcablesarereplacingcopperwireasthemajorcommunicationmediuminbuildingsandcities.Majorcommunicationscompaniesarecurrentlyinvestinghugesumsofmoneyinfiberopticscommunicationsnetworksthatcancarrydigitalsignals,thusincreasingcommunicationsandcapacity.雖然衛(wèi)星系統(tǒng)被認(rèn)為是現(xiàn)階段長距離通信的主要媒介，但光纖技術(shù)被認(rèn)為是通信工業(yè)的革命。因為它具有低廉的價格、較高的傳輸容量，低誤差率以及信息保密等優(yōu)點。光纖電纜取代銅線成為建筑物和城市的主要的通信媒介，大多數(shù)通信公司目前正在投資巨大的資金用于能夠傳輸數(shù)字信號的光纖通信網(wǎng)，以便增大信息的容量。Unit10【中譯英】(1)全球通信骨干網(wǎng)：Theglobaltelecommunicationsandnetworkingbackbone(2)波分復(fù)用：WavelengthDivisionMultiplexing(3)光脈沖：Pulsesoflightonfiber(4)調(diào)頻無線信道：FMradiochannels(5)多?；儯簃ultimodedistortion.(6)單模玻璃光纖：single-modeglassfiber【句子翻譯（英譯中）】Onereasonisthatasingleconverterfromelectricaltoopticalsignalscanonlymakeuseofasmallamountofopticspectrum,limitingtheachievablebandwidthtoabout2.5gigabitspersecond.一個主要的原因是一臺從電信號到光信號的單項轉(zhuǎn)換器只利用很少的光譜就可以把可達(dá)到的帶寬限制到大約每秒2.5兆位WiththeuseofWDM,thecapacityofasinglestrandoffiber,250microsindiameter,cancarrybetween10and80Gbps.使用WDM，直徑為250微米的單股光線的信息載量可在10至80Gpbs之間,...whilerepeatersonafiber-opticcablecanbespacedupto30km.光纜上的中繼器（轉(zhuǎn)發(fā)器）可以每隔最多30公里放一只。...oftenmadeofplastic,thatcanbedrivenbycheaplight-emittingdiodes,whilelongdistanceconnectionsusethemoreexpensivesingle-modeglassfiber,drivenbylasers.這些光纖通常由塑料做成，可由便宜的發(fā)光二極管驅(qū)動；而長距離的鏈接使用更為昂貴的單模玻璃光纖，由激光驅(qū)動。[第一段翻譯]Theglobaltelecommunicationsandnetworkingandnetworkingbackbonecontainmillionsofkilometersoffiber-opticalcabling,butweuseonlyoneten-thousandthofthepotentialbandwidththosecables.Onereasonisthatasingleconverterfromelectricaltoopticalsignalscanonlymakeuseofasmallamountofopticalspectrum,limitingtheachievablebandwidthtoabout2.5gigabitspersecond.全球通信骨干網(wǎng)絡(luò)中包含成千上萬公里光纖，但我們只能用這些光纜潛在帶寬的千分之一。一個主要的原因是一臺從電信號到光信號的單向轉(zhuǎn)換器只利用很少的光譜就可把可達(dá)到的帶寬限制到大約每秒2.5兆位。Unit12【中譯英】(1)全球移動通信系統(tǒng)globalsystemofmobilecommunication(2)時分多址TimeDivisionMultipleAccess(3)傳真和短消息服務(wù)facsimileandshortmessageservice(4)率再用和蜂窩裂變frequencyreuseandcellsplitting(5)站收發(fā)信機(jī)basestationtransceiver(6)突發(fā)脈沖傳輸模式bursttransmissionmode【英譯中】(1)personalcommunications個人通信(2)communicationstandards通信標(biāo)準(zhǔn)(3)networkcapacity網(wǎng)絡(luò)容量(4)mobileswitchingcenter移動交換中心(5)internationalroaming國際漫游(6)broadbandservices寬帶業(yè)務(wù)(7)jamming堵車(8)technicalspecification技術(shù)規(guī)范[第一段翻譯]Thesuccessofmobilesystemsacrosstheworldisasignthatcommunicationismovingtowardsamorepersonalized,convenientsystem.Peoplewhohavetouseamobilephoneonbusinesssoonbegintorealizethattheabilitytophoneanytime,anyplaceinone’spersonalliferapidlybecomesanecessity,notaconvenience.世界范圍移動通信的成功標(biāo)志著通信正在向著更加個人化、更加方便的通信系統(tǒng)邁進(jìn)。在商務(wù)中需使用移動電話的人們很快就認(rèn)識到在個人生活中隨時隨地打電話不僅僅帶來了方便,而且是一種必需。Unit14【中譯英】(1)模擬-數(shù)字-多媒體analog-digital-multimedia(2)模擬蜂窩技術(shù)analogcellulartechnology(3)多重制式標(biāo)準(zhǔn)multiplestandards(4)蜂窩數(shù)字分組數(shù)據(jù)cellulardigitalpacketdate(5)個人數(shù)字蜂窩分組personaldigitalcellularpacket(6)處處分組packeteverywhere【英譯中】(1)thethirdgeneration(3G)第三代移動通信技術(shù)(2)video,audioandotherapplications視頻，語言和其他應(yīng)用(3)Interneteverywhere處處上網(wǎng)(4)AsynchronousTransferMode異步傳輸模式(5)datetransmissionrates數(shù)據(jù)傳輸率[第一段翻譯]3GistheEnglishabbreviationforthe3rdgenerationmobilecommunication.Incontrasttothefirstgenerationanalogstandardphone(1G)andthesecondgenerationGSM,TDMAdigitalmobilephones(2G),