通信与电子信息科技英语 总.ppt

Exercises PleasetranslatethefollowingwordsandphrasesintoChinese 1 samplefunction2 ensembleaverage 3 physicalsignificance4 aFouriertransformpair 5 deterministicwaveform6 inthelimit 7 timeinvariant8 anupper frequencylimit 9 Parseval stheorem10 randompulses 样本函数 总体均值 物理意义 傅立叶变换对 确定性波型 在极限情况下 时不变的 频率上限 巴塞瓦尔定理 随机脉冲 Exercises PleasetranslatethefollowingwordsandphrasesintoEnglish 1 随机过程2 统计平均 3 随机变量4 自相关函数 5 傅里叶变换6 功率谱密度 7 概率密度函数8 高斯过程 9 平稳过程10 统计独立 randomprocess statisticalaverage randomvariable autocorrelationfunction Fouriertransform powerspectraldensity probabilitydensityfunction gaussianprocess astationaryprocess statisticallyindependent 11 时间平均 值 12 统计特性 13 各态历经过程14 狄拉克函数 timeaverage statisticalcharacteristic ergodicprocess deltafunction Exercises Fillintheblankswiththemissingword s 1 Theensembleaverageswillbeidenticalthestatisticalaveragesandmayberepresentedbythesamesymbols 2 TheaveragesdeterminedbymeasurementsasinglesampleFunctionsuccessivetimeswillyieldatimeaverage whichwerepresentasn2 t1 3 Suppose forexample thatthestatisticalcharacteristicsofthesampleFunctionstheensemblewerechangingwithtime 4 Foritmayhappenthatwhileeachsamplefunctionisstationarytheindividualsamplefunctionsmaydifferstatisticallyoneanother 5 Asanextensionofthatresultweshalldefinethepowerspectraldensityofarandomprocessthesameway with on at in from in Exercises 6 ItisinteresttoinquirewhetherG f definedEq 1 2 forarandomprocesshasaphysicalsignificancewhichcorrespondstothephysicalsignificanceofG f fordeterministicwaveforms 8 Hence ifweshouldselectsomesamplefunction aknowledgeofthevalueofn t attimetwouldbenoassistanceimprovingourabilitytopredictthevalueattainedbythatsamesamplefunctionattimet 9 Hence wheneverwemakeanobservationormeasurementofthepulsewaveformwhichextendsadurationlongenoughsothattheaverageobservedpulseshape suchastheiramplitudes widths andspacingsarerepresentativeofthewaveformgenerally weshallfindthatEq 1 12 applies of in of in over Exercises 10 Letusselectasectionofthiswaveformwhichextends T 2 T 2 11 Sincewehaveassumedanergodicprocess weareatlibertyto perform performing theaveraginganysamplefunctionoftheensemble sinceeverysamplefunctionwillyieldthesameresult to from perform over PleasetranslatethefollowingwordsandphrasesintoChinese 1 physicalsyste2 risetime 3 amountofinformation4 inprinciple 5 gaussianchannel6 probabilitydensity 7 root mean square8 tradeoff 9 lowerbound1 equalizer 11 viceversa12 upperlimit Exercises 物理系统 实际系统上升时间 信息量理论上 原则上 高斯信道概率密度 均方根值 均方根 均方根 的 交替换位 折衷选择 下界 下限均衡器 反之亦然上限 PleasetranslatethefollowingwordsandphrasesintoEnglish 1 通信理论2 香农定理 3 信道带宽4 信号波形 5 理想低通滤波器6 自相关函数 7 无噪声高斯信道8 通信信道 9 信息速率10 信噪比 Exercises communicationtheory theoryofcommunications Shannon stheorem channelbandwidthsignalwaveform ideallowpassfilterautocorrelationfunction noiselessgaussianchannelcommunicationchannel informationrateSignaltonoiseratio SNR S N Exercises 11 信道容量12 双边功率谱密度 13 误码率14 奈奎斯特采样速率 15 限带高斯信道16 高斯白噪声 channelcapacityTwosidedpowerspectraldensityerrorprobability probabilityoferror Nyquistsamplingrate bandlimitedgaussianchannelwhiteGaussiannoise Exercises Fillintheblankswiththemissingword s 1 ThereisanegativestatementassociatedShannon stheorem 2 thepurposeoftransmissionoverthechannel themessagesarerepresentedbyfixedvoltagelevels 3 SincethetransmissionofanyoftheMmessagesisequallylikely H log2M thusourchannelistransferringinformationarateR rH 4 Forafixedsignalpowerandthepresenceofwhitegaussiannoisethechannelcapacityapproachesanupperlimitwithincreasingbandwidth 5 Itisgreatinteresttorecognizethatthetradeoffbetweenbandwidthandsignaltonoiseratioisnotlimitedbyalowerlimitbandwidth with on at in of in Exercises 6 ThesignalistransmittedachannelwhichcanberepresentedasalowpassRCcircuitwithcutoffat1Hz 7 Ifthereisnonoise thenweareentirelyfreetomakefortheattenuationbytheuseofanamplifierandtocorrectthefrequencydistortionbytheuseofanequalizer 8 Thatis weneedtoestimatetheintervalTwhichshouldbeassignedtoeachmessagetoallowthetransmittedlevelstoberecognizedIndividuallythereceiver eventhoughthebandwidthBofthechannelislimited 9 Therefore the25percentreductionbandwidthrequiresa60percentincreasesignalpower in as in of over Exercises 10 Whilewehaveusedthetermcommunicationchannelmanyoccasions itiswelltoemphasizeatthispoint thattheterm whichisSomethinganabstraction isintendedtoencompassallthefeaturesandcomponentpartsofthetransmissionsystemwhichintroducenoiseorlimitthebandwidth 11 TheprobabilityoferroriscloseunityforeverypossiblesetofMtransmittersignals 12 ItturnsouttheresultsobtainedforagaussianchanneloftenprovidealowerboundtheperformanceofasystemOperatinganongaussianchannel in that in to in as PleasetranslatethefollowingwordsandphrasesintoChinese 1 overallperformance2 crestfactor 3 nonlinearoperation4 inverseoperation 5 rms6 PAM 7 PDM8 PPM 9 maximummagnitude10 errorintervals 11 Entropy12 roundoff 13 quantumlevel14 DPCM Exercises 总性能振幅 波峰 因数 振幅与有效值之比 非线性运算逆操作 均方根 值 脉幅调制 pulseamplitudemodulation 脉宽调制 pulsedurationmodulation 脉 冲相 位调制 pulsephasemodulation 最大幅值误差间隔 熵 平均信息量舍入 用四舍五入化为整数 量化电平 差分脉冲编码调制 differentialpulsecodemodulation Exercises PleasetranslatethefollowingwordsandphrasesintoEnglish 1 正脉冲2 脉冲编码调制 3 解码器4 编码器 5 量化步长6 峰值 7 线性函数8 脉冲序列 9 均匀量化器10 预测编码 11 压扩器12 压缩比 positivepulsepulsecodemodulation PCM decoderencoder quantumstepsizepeakmagnitudes linearfunctionpulsetrain uniformquantizerpredictivecoding Compandorcompressionratio Exercises Fillintheblankswiththemissingword s 1 PCMisawidelydifferentformofmodulationcomparedwiththeanalogpulsetypessuchPAM PDM andPPM 2 Thecharacteristicsofthepulsegrouparerelatedthemessagesamplethroughoperationscalledquantizationandcoding 3 Thetermsymbolcoderdistingnishesthiscodingoperationtheoverallsourceencodingprocess Inmostcases avariable lengthcodeisusedtorepresentthemappedandquantizeddataset Itassignstheshortestcodewordsthemostfrequently occurring occure occurred outputvaluesandthusreducescodingredundancy 4 Thus aquantizationerrorexistsPCMand aswillbeseen isthe Basiclimitationinperformance 5 Quantizationandsamplingproducethesameresultsamplingandquantizing as to from to occuring in as Exercises 6 Forequalpeakmagnitudes signalswithlargecrestfactorsgivepoorerperformancethosewithsmallKcr 7 Inthereceivertheinverseoperationisimplementedanexpandorrestoretheoriginalmessage 8 Thedigitaldataisfedseriallythedecoder 9 theratedrops samplesaremadelessfrequentlyandstepsizesincrease 10 Theactualcompressionratioresultingthismethodisnomorethananorderof4 1 11 Inanattemptto reduce reducing thenumberofcodessentbyaPCMsystem aslightvariancesamplingmethodisusedbyasystemknownDifferentialPulseCodeModulation DPCM than by to into as from reduce on as Exercises PleasetranslatethefollowingwordsandphrasesintoChinese 1 channelcoding2 transmissionbandwidth 3 Singlesidednoisepowerdensity4 orthogonalsignaling 5 FEC6 logictable 7 systematiccode8 AWGN 信道编码传输带宽 单边带噪声功率密度正交信号 前向纠 forwarderrorcorrection 逻辑表系统码 加性高斯白噪声 additivewhiteGaussiannoise Exercises 9 BER10 trellisdiagram 11 constraintlength12 vectorarray 13 algebraicfunction14 statediagram 15 cyclicshift16 generatormatrix 误码率 误比特率 BitErrorRatio 网格图 制约长度向量数组 矩阵 代数函数状态图 循环移位生成矩阵 Exercises PleasetranslatethefollowingwordsandphrasesintoEnglish 1 检错码2 信道容量 3 分组码4 卷积码 5 移位寄存器6 汉明距离 7 码重8 树形图 9 编码增益 errordetectioncodeschannelcapacity blockcodesconvolutionalcodes shiftregisterHammingdistance codeweight weightofacode treediagram codinggain Exercises 10 平均比特能量 11 码距12 纠错码 13 带宽效率14 模2加法器 15 原始数据16 编码率 17 生成多项式18 循环码 averagebitenergy codedistance distanceofacode errorcorrectioncodes bandwidthefficiencymodulo2adder rawdatacoderate generatorpolynomialcycliccodes Exercises Fillintheblankswiththemissingword s 1 Channelcodingprotectsdigitaldataerrorsbyselectivelyintroducingredundanciesinthetransmitteddata 2 Byproperencodingoftheinformation errorsinducedanoisychannelcanbereducedanydesiredlevelwithoutsacrificingtherateofinformationtransfer 3 Errorcontrolcodingwaveforms theotherhand havebandwidthexpansionfactorsthatgrowonlylinearlythecodeblocklength 4 Inablockencoder kinformationbitsareencodedncodebits from by to on with into Exercises 5 Theblockcodeisreferredtoan n k code andtherateofthecodeisdefinedRc k n andisequaltherateofinformationdividedbytherawchannelrate 6 Convolutionalcodesarefundamentallydifferentblockcodesinthatinformationsequencesarenotgroupeddistinctblocksandencoded 7 Thetreediagramshowsthestructureoftheencodertheformofatreewiththebranches represent represented representing thevariousstatesandtheoutputsofthecoder 8 ThisreducesthebandwidthefficiencyofthelinkhighSNRconditions butprovidesexcellentBERperformancelowSNRvalues 9 Asystematiccodeisonewhichtheparitybitsareappendedtheendoftheinformationbits 10 Achannelcoderoperatesdigitalmessage orsource databyencodingthesourceinformationacodesequencefortransmissionthechannel as to as from into in representing in at in to on into through Exercises PleasetranslatethefollowingwordsandphrasesintoChinese 1 AM2 DPSK 3 PAM4 PDM 5 PPM6 PCM 7 DPCM8 ASK 9 FSK10 FDM 11 TDM12 codedmodulation 13 suppressedcarrier14 modulatedsignal 幅度调制 amplitudemodulation 差分相位键控 DifferentialPSK 脉 冲振 幅调制 pulseamplitudemodulation 脉宽调制 pulsedurationmodulation 脉 冲相 位调制 pulsephasemodulation 脉 冲编 码调制 pulsecodemodulation 差分脉冲编码调制 differentialpulsecodemodulation 振幅键控 amplitude shiftkeying 移频键控 frequency shiftkeying 频分 多路 复用 frequency divisionmultiplexing 时分 多路 复用 time divisionmultiplexing 编码调制 抑制载波 已调信号 Exercises PleasetranslatethefollowingwordsandphrasesintoEnglish 1 带通信号2 脉冲调制 3 角度调制4 残留边带抑制载波调制 5 绝对带宽6 脉冲宽度 7 线性函数8 载波频率 9 模拟调制10 移相键控 11 连续波调制12 同轴电缆 bandpasssignalpulsemodulation anglemodulation Vestigialsidebandsuppressedcarriermodulationabsolutebandwidthpulseduration linearfunctioncarrierfrequency analogmodulationPSK phaseshiftkeying continuouswave cw modulationcoaxialcable Exercises Fillintheblankswiththemissingword s 1 Themethodinvolvesfirstsamplingtheinformationsignal quantizingthesamplebyroundingofftotheclosestofanumberofdiscretelevels andfinallygeneratingaprescribednumberofpulsesaccordingtoacoderelatedtothenearestdiscretelevel 2 Codedmodulationwillalsobereferredtoasdigitalmodulation Itisoneofthemostmodernandusefulmethodsofmodulationavailabletoday 3 InPPMpulsepositionisproportionaltotheamplitudeofthemessagesignal4 Time divisionmultiplexing TDM usespulsemodulationtoputsamplesofdifferentsignalsinnonoverlappingtimeslots Forinstance thegapsbetweenpulsescouldbefilledwithsamplesfromothersignals 5 Itisoftennecessarytousemodulationtotranslatetheusefulbandoffrequenciesuptoalargecarrierfrequencysothatefficientelectromagneticradiationispossiblefromanantennahavingreasonablesize Exercises 6 Thedesignofacommunicationsystemmaybeconstrainedbythecostandavailabilityofhardware whoseperformanceoftendependsonthefrequenciesinvolved7 Fractionalbandwidthconsiderationsaccountforthefactthat modulation unitsarefoundinreceiversaswellasintransmitters 8 Thesemethodsmaybecharacterizedascontinuouswave cw modulation 9 Sinceeachstationhasadifferentassignedcarrierfrequency thedesiredsignalcanbeseparatedfromtheothersbyfiltering 10 PCMmaybeeitherbinary wherepulseshaveonlytwovoltagelevels or ary wherepulsesmaytakeon possiblelevels 11 Byexploitingthefrequencytranslationpropertyofcwmodulation messageinformationcanbeimpressedonacarrierwhosefrequencyhasbeenselectedforthedesiredtransmissionmethod Exercises PleasetranslatethefollowingwordsandphrasesintoChinese 1 copperwire2 speechrecognition 3 adaptivedifferentialPCM4 infiniteimpulseresponse IIR 5 real timeconversation6 digitalsignalprocessing 7 CELP8 VAD 9 MPE10 ADPCM 11 directquantization12 logpulsePCMquantizer 铜线语音识别 自适应差分脉码调制无限脉冲响应 实时交谈数字信号处理 码激励线性预测 codeexcitedlinearprediction 话音激活检测器 voiceactivitydetector 多脉冲激励 multipulseexcitation 自适应差分脉码调制 adaptivedifferentialPCM 直接量化对数脉冲PCM量化器 Exercises PleasetranslatethefollowingwordsandphrasesintoEnglish 1 共振峰跟踪滤波器2 国际电信联盟 3 背景噪声4 双向通信 5 基音跟踪滤波器6 长时预测 7 语音编码8 声码器 9 语音增强10 波形跟随编码器 11 参数编码器12 频域编码器 铜线语音识别 自适应差分脉码调制无限脉冲响应 实时交谈数字信号处理 码激励线性预测 codeexcitedlinearprediction 话音激活检测器 voiceactivitydetector 多脉冲激励 multipulseexcitation 自适应差分脉码调制 adaptivedifferentialPCM 直接量化对数脉冲PCM量化器 Exercises Fillintheblankswiththemissingword s 1 Speechcodingisafundamentaltechnologythathasexistedformorethan60years beginninginthe1930swithDudley soriginalvocoder 2 Speechcodingisdistinctfromthemoregeneralproblemofaudiocodinginthattheprimarysignalofinterestisthespeechitself 3 Virtuallyallexistingtelecommunicationsapplicationsbeginwithspeechcodedbythisstandard 4 Theselectionofappropriateexcitationpulsesiscarriedoutinaperceptuallyweighteddomain ratherthanjustminimizingthemseinthewaveformdomainsothatthequantizationnoiseislessaudibletothelistener 5 Signaldelayisameasureofthedurationofthespeechsignalusedtoestimatecoderparametersreliablyforboththeencoderandthedecoder plusanydelayinherentinthetransmissionchannel Exercises 6 Iftheroundtripdelayisheld holds isheld held below300msandthereissufficientechocancellation thequalityisquiteacceptable 7 Ifthenumberofbitsprovidedbythecoderovertimeisalwaysthesame therateisfixed 8 Voiceactivitydetectors VAD thatattempttodeterminewhetherspeechisactuallypresentsoastoutilizethechannelmoreefficientlywhenspeechisabsentandtoavoidtrying totry try trying tocodebackgroundsignalsasspeech 9 Instead thisclassattemptstoproduceasignalthatsoundsliketheoriginalbyusingaparametricmodelofspeech analying analyzing analyze analyzed thespeechtoestimatetheseparameters andthenquantizingonlytheparameters 10 Frequencydomaincodershavebeenselected select havebeenselected areselecting asthebasisforanewwidebandcodingrecommendationbytheITU T Exercises PleasetranslatethefollowingwordsandphrasesintoChinese 1 electromagnetic EM spectrum2 electronmicroscopy 3 radiowave4 ultrasound 5 imageunderstanding6 framebuffer 7 imagesensor8 电磁波频谱电子显微镜 无线电波超声 波 图像理解帧缓存器 帧缓冲 摄像传感器文件扩展名 Exercises 9 JPEG10 transmissioncapacity 11 boundaryrepresentation12 featureselection 13 ALU14 archivalstorage 15 stereodisplay16 specializedhardware 17 artificialintelligence18 flatscreen 联合图像专家组 JointPhotographicExpertsGroup 传输容量 边界表示 法 特征选择 算术逻辑单元 运算器 arithmeticlogicunit 档案库存储器 立体显示专用硬件人工智能 AI 平面屏幕 Exercises PleasetranslatethefollowingwordsandphrasesintoEnglish 1 数字图像处理2 像素 3 海量存储器4 图像分析 5 图像锐化6 图像恢复 7 数据压缩8 对比度增强 digitalimageprocessingpixel pel pictureelement imageelement massstorageimageanalysis imagesharpeningimagerestoration datacompressioncontrastenhancement Exercises 9 分辨率10 图像显示 11 卫星图像12 光盘 13 小波14 计算机视觉 15 图像退化16 图像采集 17 磁盘18 目标识别 Resolutionimagedisplay satelliteimageopticaldisk opticaldisc waveletcomputervision imagedegradationimageacquisition magneticdiskobjectrecognition Exercises Fillintheblankswiththemissingword s 1 Thefieldofdigitalimageprocessingreferstoprocessingdigitalimagesbymeansofadigitalcomputer 2 Theseelementsarereferredtoaspictureelements imageelements pels andpixels 3 Visionisthemostadvancedofoursenses soitisnotsurprisingthatimagesplaythesinglemostimportantroleinhumanperception 4 Sometimesadistinctionismadebydefiningimageprocessingasadisciplineinwhichboththeinputandoutputofaprocessareimages 5 Alowlevelprocessischaracterizedbythefactthatbothitsinputsandoutputsareimages 6 Imageacquisitioncouldbeassimpleasbeinggivenanimagethatisalreadyindigitalform Exercises 7 Itisimportanttokeepinmindthatenhancementisaverysubjectiveareaofimageprocessing 8 Imagecompressionisfamiliar perhapsinadvertently tomostusersofcomputersintheformofimage 9 Segmentationprocedurespartitionanimageintoitsconstituentpartsorobjects 10 Forexample underthisdefinition eventhetrivialtaskofcomputingtheaverageintensityofanimagewouldnotbeconsideredanimageprocessingoperation 11 Weconcludeourcoverageofdigitalimageprocessingwiththedevelopmentofmethodsforrecognitionofindividualobjects 12 Indedicatedapplications sometimesspeciallydesinged design designed designing computersareusedtoachieve arequiredlevelofperformance butourinteresthereisongeneral purposeimageprocessingsystems Exercises PleasetranslatethefollowingwordsandphrasesintoChinese 1 matrixcomputation2 controlsystemdesign 3 earthandlifescience4 openarchitecture 5 I O6 structuredlanguage 7 matrixfactorization8 imageprocessingtoolbox 9 add on10 curvefitting 矩阵计算控制系统设计 地球和生命科学开放型结构 输入 输出 Input Output 结构化语言 矩阵因数分解图像处理工具箱 附加曲线拟合 法 Exercises 11 externalroutine12 time consuming 13 descriptivestatistics14 PDE 15 geographicmapping16 datastructure 17 state of the art18 GUI 19 OOP20 iterativemethod 外部 例行 程序耗费时间的 旷日持久的 描述统计 学 偏微分方程 partialdifferentialequation 地理制图数据结构 目前发展水平 发展现状图形用户接口 graphic al userinterface 面向对象程序设计 objectorientedprogramming 迭代法 Exercises PleasetranslatethefollowingwordsandphrasesintoEnglish 1 矩阵2 数值积分 3 数据采集4 线性代数 5 部分分数展开6 嵌入式界面 7 奇异值8 常微分方程 9 稀疏矩阵10 面向对象的程序设计 11 初值12 特征向量 Matrixnumericalintegration dataacquisitionlinearalgebra partialfractionexpansionbuilt ininterface singularvaluesODE ordinarydifferentialequation sparsematrixOOP ObjectOrientedProgramming initialvalueeigenvector Exercises Fillintheblankswiththemissingword s 1 MATLABhasevolvedoveraperiodofyearswithinputfrommanyusers 2 SimulinkprovidesablockdiagraminterfacethatisbuiltonthecoreMATLABnumeric graphics andprogrammingfunctionality 3 UsershavefoundthatthecombinationoftheintuitiveMATLABinterface language andthebuilt inmathandgraphicsfunctionsmakeMATLABthepreferredplatformfortechnicalcomputingcomparedtoC Fortran andotherlanguagesandapplications 4 Usingthebuilt inmathandgraphicsfunctionsandeasy to usetools youcananalyzeandvisualizeyourdataonthefly 5 Thesealgorithms developedbyexpertsinmathematics arethefoundationoftheMATLABlanguage Exercises 6 Themathisoptimizedformatrixandvectoroperations soyoucanuseitinplaceoflow levellanguageslikeCandC 7 Thesefunctionsareintendedtohelpscientistsandengineersvisualizeandunderstandlarge oftencomplex multidimensionaldata 8 Languagefeaturesincludedatastructures object orientedprogramming OOP graphicaluserinterface GUI developmenttools debuggingfeatures andtheabilitytolinktoC C Fortran andJavaroutines 9 WithMATLAB youcancustomizevirtually virtually virtual anyaspectofyourplotsandproducehigh qualitygraphicsforwrittenandlivepresentations 10 MAT