第2章信息与通信工程专业英语(第2版)_韩定定

第2章ApplicationandAppreciation★LessonOneModernDigitalDesign&DigitalSignalProcessing★LessonTwoEmbeddedSystemsandApplications★LessonThreeVirtualInstruments★LessonFourDesignPatterns第2章ApplicationandAppreciation★LessonFiveDigitalImageProcessing&VideoCompression★LessonSixTechnologyofModernCommunication★LessonSevenWirelessSensorNetworks★LessonEightCryptology第2章ApplicationandAppreciation★LessonNineComplexNetworksandItsApplications★LessonTenCloudComputingLessonOneModernDigitalDesign&DigitalSignalProcessing＊TextA:IntroductiontoDigitalSignalProcessing＊TextB:ModernDigitalDesignLessonOneModernDigitalDesign&DigitalSignalProcessingTextAIntroductiontoDigitalSignalProcessingDigitalSignalProcessingisoneofthemostpowerfultechnologies….EachoftheseareashasdevelopedadeepDSPtechnology,withitsownalgorithms,mathematics,andspecializedtechniques.ThiscombinationofbreathanddepthmakesitimpossibleforanyindividualtomasteralloftheDSPtechnologythathasbeendeveloped.…andlearningspecializedtechniquesforyourparticularareaofinterest.每个研究领域都在它自身特有的算法、数学和技术的基础上更深入地开发DSP技术，从而使DSP技术在广度和深度两个方面都得到拓展，因此，任何人都不可能掌握所有现存的DSP技术。LessonOneModernDigitalDesign&DigitalSignalProcessingTextAIntroductiontoDigitalSignalProcessingThedevelopmentofdigitalsignalprocessingdatesfromthe1960'swiththeuseofmainframedigitalcomputersfornumber-crunchingapplicationssuchastheFastFourierTransform(FFT),whichallowsthefrequencyspectrumofasignaltobecomputedrapidly.Thesetechniqueswerenotwidelyusedatthattime,becausesuitablecomputingequipmentwasgenerallyavailableonlyinuniversitiesandotherscientificresearchinstitutions.数字信号处理技术源于20世纪60年代，彼时，大型计算机开始用于处理计算量较大的运算，例如可以快速获得信号的频谱的快速傅立叶变换（FFT）等。在本句中，Thedevelopmentofdigitalsignalprocessing是主语，datesfrom是谓语，意思是起源于历史上的某一个年代。后面以which引导的定语从句用于修饰FFT。LessonOneModernDigitalDesign&DigitalSignalProcessingTextAIntroductiontoDigitalSignalProcessingThistechnologicalrevolutionoccurredfromthetop-down.…Whilestilltherealmofelectricalengineering,nearlyeveryscientistandengineerhassomebackgroundinbasiccircuitdesign.Withoutit,theywouldbelostinthetechnologicalworld.DSPhasthesamefuture.DSPhasrevolutionizedmanyareasinscienceandengineering.AfewofthesediverseapplicationsareshowninFigure1.没有基本的电路设计的背景（经验），他们将会被技术界淘汰。it是指前一句中的somebackgroundinbasiccircuitdesign。lost的原意是丢失,这里意译为“淘汰”。LessonOneModernDigitalDesign&DigitalSignalProcessingTextAIntroductiontoDigitalSignalProcessingTheintroductionofthemicroprocessorinthelate1970'sandearly1980'smadeitpossibleforDSPtechniquestobeusedinamuchwiderrangeofapplications.…(NotethattheacronymDSPcanvariouslymeanDigitalSignalProcessing,thetermusedforawiderangeoftechniquesforprocessingsignalsdigitally,orDigitalSignalProcessor,aspecializedtypeofmicroprocessorchip).…需要注意的是，缩写DSP有多种含义，它既可以解释为“数字信号处理”，也可以解释为“数字信号处理器”，前者表示一种目前被广泛采用的数字信号处理技术，后者则表示一种专用的微处理器芯片。LessonOneModernDigitalDesign&DigitalSignalProcessingTextAIntroductiontoDigitalSignalProcessingThereareapproximatelyonebilliontelephonesintheworld.Atthepressofafewbuttons,switchingnetworksallowanyoneofthesetobeconnectedtoanyotherinonlyafewseconds.…Incomparison,DSPconvertsaudiosignalsintoastreamofserialdigitaldata.Sincebitscanbeeasilyintertwinedandlaterseparated,manytelephoneconversationscanbetransmittedonasinglechannel.Thistechnologyiscalledmultiplexing.比较而言，DSP可以将音频信号转变为数据流。由于数字比特易于组合与分离，因此，多路电话信号可以通过一条信道实现传输，这种技术称为复用。LessonOneModernDigitalDesign&DigitalSignalProcessingTextAIntroductiontoDigitalSignalProcessingWhenavoicesignalisdigitizedat8000samples/sec,mostofthedigitalinformationisredundant.Thatis,theinformationcarriedbyanyonesampleislargelyduplicatedbytheneighboringsamples.DozensofDSPalgorithmshavebeendevelopedtoconvertdigitizedvoicesignalsintodatastreamsthatrequirefewerbits/sec.Thesearecalleddatacompressionalgorithms.…当对话音信号在8000次/秒的采样率基础上进行编码时，获得的数字信号存在冗余，也就是说，某一采样点的信息在很大程度上与其它采样点的信息重复。LessonOneModernDigitalDesign&DigitalSignalProcessingTextAIntroductiontoDigitalSignalProcessingNewWordsandExpressionsalgorithmn.算法sonarn.声纳，声波定位仪ECG=Electrocardiograph心电图FourierTransform傅立叶变换programmableadj.可编程的multiplexing多路复用技术amplifiern.放大器transducern.传感器，变频器LessonOneModernDigitalDesign&DigitalSignalProcessingTextAIntroductiontoDigitalSignalProcessinguncompression解压缩digitalrecording数字式录音featureextraction特征抽取reproductionn.再现，再生electroden.电极noisen.噪声mainssupply交流电源electronicvoicemail语音邮件LessonOneModernDigitalDesign&DigitalSignalProcessingTextAIntroductiontoDigitalSignalProcessingHilbertTransform希尔伯特变换redundantadj.多余的，冗余的filteringn.滤波datacompression数据压缩artificialreverberation人工混响vocaltractsimulation声音模拟器speechgeneration语音产生featurematching特征匹配LessonOneModernDigitalDesign&DigitalSignalProcessingTextBModernDigitalDesignThespeedoflightisjusttooslow.…Thesesystemsoperateathighfrequenciesatwhichconductorsnoongerbehaveassimplewires,butinsteadexhibithigh-frequencyeffectsandbehaveastransmissionlinesthatareusedtotransmitorreceiveelectricalsignalstoorfromneighboringcomponents.Ifthesetransmissionlinesarenothandledproperly,theycanunintentionallyruinsystemtiming.…当系统工作于高频段时，导体不再是简单的导线，此时，导体将具表现出高频特性，即具有传输线的功能和特性，该特性使得导体能与相邻器件之间实