通信专业英语ppt课件

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1、通信与电子信息工程通信与电子信息工程专业英语专业英语English for Communication and Electronic Information Engineering 学习本课程的目的学习本课程的目的 掌握专业英文的阅读、翻译、写作的基本方法；掌握专业英文的阅读、翻译、写作的基本方法； 学习、积累英文专业词汇；学习、积累英文专业词汇； 了解专业领域的一些技术、知识。了解专业领域的一些技术、知识。本课程的主要内容本课程的主要内容 专业英语基础知识专业英语基础知识 精选专业文献的阅读、讲解及翻译练习精选专业文献的阅读、讲解及翻译练习 专业文献专业文献(摘要摘要)的写作练习的写作练习学

2、习本课程的主要方式学习本课程的主要方式 课前预习课前预习 课堂讲解重点难点课堂讲解重点难点 课后练习课后练习 课堂练习、小测课堂练习、小测建议建议v准备笔记本准备笔记本v准备英汉专业词典准备英汉专业词典要求要求v独立完成作业独立完成作业v遵守课堂纪律遵守课堂纪律Lesson 0 科技英语基础知识科技英语基础知识 The Basic Knowledge of Scientific and Technical EnglishLesson 0 科技英语基础知识科技英语基础知识 The Basic Knowledge v0.1 科技英语的特点科技英语的特点 featuresv0.2 专业英文翻译概述专

3、业英文翻译概述 Translationv0.3 专业英文翻译的几种基本方法专业英文翻译的几种基本方法 Translation Methodsv0.4 关于数量关于数量 Numbers and Quantitiesv0.5 关于数学符号和数学式关于数学符号和数学式 Mathematic symbols and Expressionsv0.6 关于图、表关于图、表 Figures and Tablesv0.7 专业英文的写作专业英文的写作 Writing科技英语与普通英语相比有自己的特点科技英语与普通英语相比有自己的特点:v 常包含一些数据、公式、符号、图表、程序等常包含一些数据、公式、符号、图表

4、、程序等v 语言简练、结构严谨、表达明确、概念清晰语言简练、结构严谨、表达明确、概念清晰v 语法上特点：语法上特点：常用一般现在时时态；常用一般现在时时态； 复杂长句多；复杂长句多； 被动语态多；（被动语态多；（“被被”、“经过经过”、“受了受了”、“由于由于”） 非谓语动词多；（动名词、分词、不定式）非谓语动词多；（动名词、分词、不定式） 非人称语气，常用非人称语气，常用It作主语；作主语； 条件句多，常用条件句多，常用If 语句。语句。0.1 科技英语的特点科技英语的特点 featuresv 词汇的特点：词汇的特点： 大量使用专业词汇、转意词汇；大量使用专业词汇、转意词汇； 较多使用词性转

5、换较多使用词性转换adjn,nv,等等；等等； 较多使用词缀、词根，甚至用词缀词根创造新词；较多使用词缀、词根，甚至用词缀词根创造新词； 大量使用专业缩写词；大量使用专业缩写词； 新专业词汇、缩写词不断出现。新专业词汇、缩写词不断出现。科技英语与普通英语相比有自己的特点科技英语与普通英语相比有自己的特点:0.1 科技英语的特点科技英语的特点 featurescode n.码 v. 编码variable adj.可变的，易变的 n.变量 multiple adj.多样的 n.倍数 the least common 合成词：multimeter 万用表，interface 接口、界面code-de

6、code codec 编解码coder-decoder codec 编解码器modulator-demolatormodem 调制解调器Interactive-network internet 互联网、因特网transmitter-receiver transceiver 收发器GSM , GPRS , CDMA , GPS , CPU , USB , LCD0.1 科技英语的特点科技英语的特点 features0.1.1 长句长句 Long sentences有两种方法简化长句，以正确把握长句句意有两种方法简化长句，以正确把握长句句意 依据关键词简化词组。依据关键词简化词组。e.g.Ther

7、atioofthecapacitancewithsomematerialotherthanairbetweentheplates,tothecapacitanceofthesamecapacitorwithairinsulation,iscalledthedielectricconstantofthatparticularmaterial.ratio is called constant依据谓语动词把复合句分解成一组简单句。依据谓语动词把复合句分解成一组简单句。the ratio of A to B ：A与B的比率Insulation 绝缘，insulated ，insulatingdiele

8、ctric constant 介电常数0.1 科技英语的特点科技英语的特点 features0.1.1 长句长句 Long sentencese.g.This electron beam sweeps across each line at a uniform rate，then flies back to scan another line directly below the previous one and so on，until the horizontal lines into which it is desired to break or split the picture hav

9、e been scanned in the desired sequence electron beam 电子束at a uniform rate 以均匀的速率scan 扫描horizontal lines 水平行线in the desired sequence 按希望的顺序e.g. For direct current and low-frequency alternating current (up to a few thousand cycles per second) the resistance is reversely proportional to the cross-secti

10、onal area of the path the current must travel; that is , given two conductors of the same material and having same length , but differing in crossing-sectional area , the one with larger area will have the lower resistance.0.1 科技英语的特点科技英语的特点 features0.1.1 长句长句 Long sentencesresistance is reversely p

11、roportional to area,that is,one will have the lower resistance. A与与B成成(正正/反反)比例比例 (directly)A be (reversely) proportional to B (inversely ) (direct)A be in (reverse) proportion/ratio to B (inverse) (reciprocal) They are in a ratio of 3 to 7. 它们之间比率为3比7。0.1 科技英语的特点科技英语的特点 features0.1.1 长句长句 Long sent

12、encese.g. These inexpensive and relatively fast digital circuits have made it possible to construct highly sophisticated digital systems that are capable of performing complex digital signal processing functions and tasks, which are usually too difficult and/or too expensive to be performed by analo

13、g circuitry or analog signal processing systems.主干：digital circuits have made it possible to construct digital systemsthat引导的定语从句修饰digital systemswhich引导的定语从句修饰functions and tasks0.1.2 词汇词汇 Vocabularies or wordsv普通词汇普通词汇 Common vocabularies0.1 科技英语的特点科技英语的特点 featuresv专业词汇专业词汇 Speciality vocabularies

14、 大部分是名词、名词词组，少量形容词，词意单一，用法简单。0.1.2 词汇词汇 Vocabularies or wordsv专业词汇专业词汇 Speciality vocabularies0.1 科技英语的特点科技英语的特点 featureselectronic电子的mail（Email）electric电的voltage，current，resistanceelectrical电气的engineer，propertyelectro-电-electromagneticwave，electrodynamicelectrode电极anode阳极、正极cathode阴极、负极positive阳性的、

15、正的、正数negative阴性的、负的、负数0.1.2 词汇词汇 Vocabularies or words0.1 科技英语的特点科技英语的特点 featuresdiode二极管triode三极(真空)管oscillator振荡器oscilloscope示波器oscillo-波动radio无线电、收音机radar雷达laser激光Ohmslaw欧姆定律amplifier放大器transistor晶体管、三极管field-effecttransistor场效应晶体管（FET）v专业词汇专业词汇 Speciality vocabulariesv转意词汇转意词汇 Transfered words 0

16、.1 科技英语的特点科技英语的特点 features0.1.2 词汇词汇 Vocabularies or words 从普通词汇借用、移植过来，赋予了专业含义。出现在专业文献中，一般就是使用其专业含义。resistance 阻力,抵抗,敌对 电阻电阻(值值)current水流,气流,趋势,当前的电流电流charge装载,起诉,负责,载荷电荷电荷, 充电充电 circuit周围,巡回,绕行电路电路v转意词汇转意词汇 Transfered words 0.1 科技英语的特点科技英语的特点 features0.1.2 词汇词汇 Vocabularies or wordsbus 公共汽车总线总线net

17、work网、网状组织网络网络rectifier 修正者整流器整流器 monitor班长显示器、监视器显示器、监视器power力量、动力电源、功率、动力、电力、幂电源、功率、动力、电力、幂field 田野,场地,领域（电、磁）场（电、磁）场regulator 调整者稳压器稳压器v转意词汇转意词汇 Transfered words 0.1 科技英语的特点科技英语的特点 features0.1.2 词汇词汇 Vocabularies or wordsresistance ：电阻，电阻值：电阻，电阻值 resistor ：电阻（器）：电阻（器）capacitance：电容，电容值：电容，电容值 cap

18、acitor：电容：电容（器）（器）inductance：电感，电感值：电感，电感值 inductor：电感：电感（器）（器）parallel serial ：并行串行：并行串行parallel series： 并联串联并联串联analog digital ：模拟的数字的：模拟的数字的continuous discrete： 连续的离散的连续的离散的v转意词汇转意词汇 Transfered words 0.1 科技英语的特点科技英语的特点 features0.1.2 词汇词汇 Vocabularies or words有些单词的通用含义很接近，但它们的专业含义却完全不有些单词的通用含义很接近，

19、但它们的专业含义却完全不同，如：同，如：differential ：微分：微分 difference ：差分：差分probability ：概率：概率 possibility ：可能性：可能性 转意词汇还有：转意词汇还有：failure，relay，antenna，coherent，filter，spectrum，modulator，flip-flop，potential , carrier , line , loop 等等等等v专业缩写词 Speciality Abbreviations0.1 科技英语的特点科技英语的特点 features0.1.2 词汇词汇 Vocabularies or

20、 wordsFET-field-effecttransistor场效应管IC-integratedcircuit集成电路USB-UniversalSerialBas通用串行总线AM-amplitudemodulation幅度调制、调幅FM-frequencymodulation频率调制、调频 通信、电信技术发展飞速，新缩写词不断出现。DC. dc.-directcurrent直流AC. ac.-Alternatingcurrent交流v专业缩写词 Speciality Abbreviations 有些是组织机构的缩写，如：0.1 科技英语的特点科技英语的特点 features0.1.2 词汇词

21、汇 Vocabularies or wordsITU -InternationalTelecommunicationsUnion国际电信联盟IEEE - InstituteofElectricalandElectronicsEngineering电气与电子工程师协会ISO - InternationalStandardizationOrganization 国际标准化组织还有还有IEC , ANSI，AT&T, APT 等等等等v专业缩写词 Speciality Abbreviations0.1 科技英语的特点科技英语的特点 features0.1.2 词汇词汇 Vocabularies or

22、 wordsLAN - localareanetwork局域网WWW -worldwideweb全球网、万维网MAN MetropolitanAreaNetwork城域网WAN WideAreaNetwork广域网HTTP - HypertextTransferProtocol超文本传输协议GPRS-GeneralPacketRadioService通用无线分组业务ASCII -AmericanStandardCodeforInformationInterchange美国信息交换标准码ISDN - integratedservicesdigitalnetwork综合业务数字网v专业缩写词 Sp

23、eciality Abbreviations0.1 科技英语的特点科技英语的特点 features0.1.2 词汇词汇 Vocabularies or words还有：CPU,RAM,ROM,DOS,RTOS,FTP,TCP/IP,LCD,LED,ADC,DAC,DSP,ADSL,PAL,NTSC,radar,laser。等等FFT -FastFourierTransform快速傅立叶变换IFFT - InverseFastFourierTransform逆快速傅立叶变换ATM -AutomaticTellerMachine自动取款机AsynchronousTransferMode异步转移（传

24、递）模式CRT -CathodeRayTube阴极射线管（显示器）ChineseRemainderTheorem中国剩余定理存在不同全称含义对应同一个缩写形式的情况。 0.2 专业英文翻译概述专业英文翻译概述 Translation0.2.1 翻译的准则翻译的准则 The Criteria of Translation信True 达达 Smooth 雅雅 Refinede.g.Becausecomputersarebinarymachines,theprogramstoredinacomputersmainmemorymustbeinbinaryform.Fewprogrammersactua

25、llywritemachine-levelinstructions,however.因为计算机是二进制的机器，存储在计算机主存储器里的程序必须是二进制形式。然而，实际上极少程序员使用机器级的指令。binary 二进制 octal 八进制decimal 十进制 hexadecimal 十六进制machine language 机器语言assembler / assembly language 汇编语言 high-level language 高级语言 0.2 专业英文翻译概述专业英文翻译概述 Translation0.2.1 翻译的准则翻译的准则 The Criteria of Translat

26、ione.g.IntheANDcircuit,“1”signalsonallinputsgivea“1”output;outputis“0”,ifallinputsarenot“1”.在“与”电路中,若所有输入端为“1”信号,则输出“1”;若所有输入端不是“1”,则输出“0”。在“与”电路中,若所有输入端为“1”信号,则输出“1”;若输入端不全为“1”,则输出“0”。错 0.2.1 翻译的准则翻译的准则 The Criteria of Translatione.g.Asrubberpreventselectricityfrompassingthroughit,itisusedasinsulat

27、ingmaterial.因为橡胶阻止电通过，所以用作绝缘材料。e.g.WaterlooBridge魂断蓝桥因为橡胶不导电，所以用作绝缘材料。信信达达雅雅0.2 专业英文翻译概述专业英文翻译概述 TranslationvStep 1 先大致浏览一遍全文，了解专业背景，理解先大致浏览一遍全文，了解专业背景，理解大意。大意。vStep 2 查词典掌握生词含意。查词典掌握生词含意。vStep 3 用中文将原作表达出来，力求忠实原作，通用中文将原作表达出来，力求忠实原作，通顺流畅，可对原作作适当增删或延伸。顺流畅，可对原作作适当增删或延伸。vStep 4 检查校对。检查校对。0.2.2 翻译的基本步骤翻

28、译的基本步骤The steps of Translation0.2 专业英文翻译概述专业英文翻译概述 Translatione.g. Incomputerweusebittorepresenttheminimumdata. 在计算机中我们用位来表示最小的数据。在计算机中我们用位来表示最小的数据。0.3 专业英文翻译的几种基本方法专业英文翻译的几种基本方法0.3.1 直译直译 Literal Translation 翻译中，能够直译的情况较少，一般都需要做翻译中，能够直译的情况较少，一般都需要做适当的变换、省略、增补等以符合中文的规范和习适当的变换、省略、增补等以符合中文的规范和习惯，达到惯，达

29、到“达达”的标准。的标准。中文：动词使用更多，用法更灵活中文：动词使用更多，用法更灵活英文：有冠词；大量使用介词英文：有冠词；大量使用介词0.3 专业英文翻译的几种基本方法专业英文翻译的几种基本方法0.3.2 变换变换 Changes in Translation 0.3.2.1 词性的变换词性的变换e.g. Theminiature receivingantennawasdevelopedasanalternativetothatlargeone. 这种小型接收天线是为这种小型接收天线是为取代取代那种大型天线而研制那种大型天线而研制的。的。 n.v.0.3 专业英文翻译的几种基本方法专业英文

30、翻译的几种基本方法0.3.2 变换变换 Changes in Translation 0.3.2.1 词性的变换词性的变换e.g. Gasesdifferfromsolidsinthattheformerhavegreatercompressibilitythanthelatter. 气体与固体的气体与固体的区别区别在于前者较后者有更大的可压在于前者较后者有更大的可压缩性。缩性。 v. n.e.g. Reliabilityfeaturesthiscontrolsystem. 可靠性是这个控制系统的可靠性是这个控制系统的特色特色。 v. n.0.3 专业英文翻译的几种基本方法专业英文翻译的几种基

31、本方法0.3.2 变换变换 Changes in Translation 0.3.2.2 词序的变换词序的变换名词修饰语语序名词修饰语语序e.g.Themaindevicefailuremodeissecondbreakdown.主要器件的失效模式是二次击穿。错错!器件的主要失效模式是二次击穿。0.3 专业英文翻译的几种基本方法专业英文翻译的几种基本方法0.3.2 变换变换 Changes in Translation 0.3.2.2 词序的变换词序的变换谓语状语语序谓语状语语序e.g.IntegratedcircuitsweresuccessfullydevelopedinAmericani

32、n1958.集成电路于1958年在美国研制成功。英语词序：谓语方式状语地点状语时间状语汉语词序：时间状语地点状语方式状语谓语0.3 专业英文翻译的几种基本方法专业英文翻译的几种基本方法0.3.2 变换变换 Changes in Translation 0.3.2.2 词序的变换词序的变换被动、主动语态被动、主动语态e.g.Anelectricfieldcanbeproducedbyanychargespresentinspace.电场可由空间存在的任何电荷所产生。空间存在的任何电荷均会产生电场。0.3 专业英文翻译的几种基本方法专业英文翻译的几种基本方法0.3.3 省略省略 Ellipsis

33、通常省略冠词、介词、代词等通常省略冠词、介词、代词等 e.g.Anysubstanceismadeofatoms,whetheritisagas,aliquid,orasolid.任何物质,无论是气体、液体或固体,皆由原子组成。（省略冠词） e.g.Itisthirtycubicmetersinvolume.体积是30立方米。(省略代词It、介词in)0.3 专业英文翻译的几种基本方法专业英文翻译的几种基本方法0.3.4 增补增补 Supplements e.g.ThefirsttermofFourierseriesiscalledthefundamental,theotherstheharm

34、onics.傅里叶级数的第一项称为基波,其它各项称为各项称为谐波。 e.g.ThefirsttermofFourierseriesiscalledthefundamental,theothersare calledtheharmonics.0.3 专业英文翻译的几种基本方法专业英文翻译的几种基本方法0.3.4 增补增补 Supplements e.g.Theattenuationofthefilterisnearlyconstanttowithin0.5dBovertheentirefrequencyband 该滤波器的衰减在整个频带内接近恒定在0.5 dB以内。 该滤波器的衰减近于恒定, 整

35、个频带内的变化在0.5 dB以内。0.3 专业英文翻译的几种基本方法专业英文翻译的几种基本方法0.3.4 增补增补 Supplements reading读书preparation准备工作networking联网achip一片芯片threecomputer三台计算机Thespeedisfast.速度很快。theexperts专家们0.3 专业英文翻译的几种基本方法专业英文翻译的几种基本方法0.3.5 引申引申 Extensions e.g.Theproductyieldisa sensitive functionofprocesscontrol.产品的成品率与工艺控制密切相关密切相关。 直译生

36、硬、拗口时，可在正确理解原意的直译生硬、拗口时，可在正确理解原意的基础上适当引申。基础上适当引申。e.g.Asrubberpreventselectricityfrompassingthroughit,itisusedasinsulatingmaterial.因为橡胶不导电，所以用作绝缘材料。v数制数制 0.4.1 数制数制 Number systems 0.4 关于数量关于数量 Numbers and QuantitiesBig system: ( For engineering ) Small system:everyorderofmagnitude( For common using )

37、American :everythreeordersofmagnitudeBritish :everysixordersofmagnitudeeveryfourordersofmagnitudev数制数制 0.4.1 数制数制 Number systems 0.4 关于数量关于数量 Numbers and Quantities语语v数量级数量级 常使用对应的数量级缩写，作为单位的接头词常使用对应的数量级缩写，作为单位的接头词 0.4.2 数量级和国际单位数量级和国际单位 Number systems0.4 关于数量关于数量 Numbers and Quantities 0.4.2 数量级和国际

38、单位数量级和国际单位 Number systems0.4 关于数量关于数量 Numbers and Quantitiesv国际单位制（部分）国际单位制（部分） 量量 单位单位 符号符号length meter mmass kilogram kgtime second sangle radian radelectric current ampere Aelectric capacitance farad Felectric charge coulomb C 0.4.2 数量级和国际单位数量级和国际单位 Number systems0.4 关于数量关于数量 Numbers and Quantiti

39、esv国际单位制（部分）国际单位制（部分） 量量 单位单位 符号符号electric potential volt Velectric resistance ohm electric frequency hertz Hzelectric inductance herry Helectric power watt Wthermodynamic Kelvin degree Ktemperature Celsius degree 0.4.2 数量级和国际单位数量级和国际单位 Number systems0.4 关于数量关于数量 Numbers and Quantities 0.4.2 数量级和国际单

40、位数量级和国际单位 Number systems0.4 关于数量关于数量 Numbers and Quantitieskilometer : km picofarad: pFmillisecond: ms decibel: dBMegabytes： MB以以为单位：为单位： in units of.或或 in e.g. an angle in radians current in amperes where f is in hertz and v is in volts in thousands in billions of dollars 注意单位名用复数形式注意单位名用复数形式vA is

41、N times as large/many/heavy/ as B A is N times larger/more/heavier / as B A is larger/more/heavier / than B by N times A的大小的大小/数量数量/重量重量/是是B的的N倍。倍。 A比比B大大/多多/重重/ N1倍。倍。 0.4.3 数量的增减数量的增减 Increase and Decrease0.4 关于数量关于数量 Numbers and QuantitiesvA double /treble/quadruple/quintuple 增加到二倍增加到二倍/三倍三倍/四倍四倍

42、/五倍五倍 e.g. We double the voltage.vincrease N times increase to N times increase by N times increase by a factor of N increase N-fold increase N times as much/many/ as 增加为增加为N倍，或增加了倍，或增加了N-1倍倍 （有另解）（有另解） 0.4.3 数量的增减数量的增减 Increase and Decrease0.4 关于数量关于数量 Numbers and Quantitiesvincrease by x% 增加了增加了x

43、reduce by x% 减少了减少了xvdecrease N times decrease to N times decrease by N times decrease by a factor of N decrease N-fold decrease N times as much/many/ as N-fold reduction/decrease be N times less than 减少了减少了(N1)/N倍，或减少到倍，或减少到1/N。 动词还可换动词还可换成成reduce、shorten、drop、cut down等等 0.4.3 数量的增减数量的增减 Increase a

44、nd Decrease0.4 关于数量关于数量 Numbers and Quantities 0.4.3 数量的增减数量的增减 Increase and Decrease0.4 关于数量关于数量 Numbers and Quantitiese.g.Theswitchingtimeofthenewtypetransistorisshortenedbyafactorofthree.译文译文1:新型晶体管的开关时间缩短了三分之二。译文译文2: 新型晶体管的开关时间缩短为三分之一。e.g.ThecostofTVsetswasreducedby70%.电视机的成本降低了70%。e.g.Thevoltag

45、ehasdroppedfivetimes.电压下降了五分之四。vmaximum、minimum、peak、valley、average、mean、absolute、median、optimum、upper、lower 0.4.4 最大、最小、平均等最大、最小、平均等0.4 关于数量关于数量 Numbers and Quantitiese.g.Themaximumcommunicationrateinthisnetworkis64kbps.e.g.Theupperworkingtemperaturelimitofthismachineis45. 温度上限温度上限e.g.lowerfrequenc

46、ylimit、averagetrafficload、peakvalue0.5 关于数学符号和数学式关于数学符号和数学式 Mathematic symbols and Expressions 0.5.1 常用数学符号常用数学符号 Mathematic symbolsv补充补充:0.5 关于数学符号和数学式关于数学符号和数学式 Mathematic symbols and Expressions 0.5.1 常用数学符号常用数学符号 Mathematic symbolsahalf,onehalfathird,onethirdtwothirdsonehundredandthirteenoverthr

47、eehundredfourandtwothirdsZero(O,naught)pointtwofive0.5 关于数学符号和数学式关于数学符号和数学式 Mathematic symbols and Expressions 0.5.2 常用数学式常用数学式 Mathematic Expressionsadd v. 加addend 加数summand 被加数adder 、summer 加法器plus prep.加上a. n.正(的)subtract v.减subtrahend 减数minuend 被减数subtracter 减法器minus prep.减去，a. n.负(的)0.5 关于数学符号和

48、数学式关于数学符号和数学式 Mathematic symbols and Expressions 0.5.2 常用数学式常用数学式 Mathematic Expressionsmultiply v. 乘multiplier 乘数、系数、乘法器、倍增器multiplicand 被乘数multiple 倍数divide v. 除divider 除数、系数、除法器、分频器 dividend 被除数divisor 除数、因子、分压器、约数0.5 关于数学符号和数学式关于数学符号和数学式 Mathematic symbols and Expressions 0.5.2 常用数学式常用数学式 Mathem

49、atic Expressionsaddatobisc, aaddsbisc,aandbisc , aplusbiscsubtractbfroma,asubtractsb,bfroma,aminusbmultiply abyb,amultipliedbyb, atimesbdivideabyb,adividedbyb,b intoaaoverb a b a b a b a / ba + b = c0.5 关于数学符号和数学式关于数学符号和数学式 Mathematic symbols and Expressions 0.5.2 常用数学式常用数学式 Mathematic Expressionsxs

50、quared,thesquareofx,thesecondpowerofx , x tothesecondpowerxcubed,thecubeofx,thethirdpowerofx，x tothethirdpowerthenthpowerofx，x tothepowerof nthesquarerootofx，root x thecuberootofxthenthrootofx0.5 关于数学符号和数学式关于数学符号和数学式 Mathematic symbols and Expressions 0.5.2 常用数学式常用数学式 Mathematic Expressionslogbtothe

51、basea,thelogarithmofbtothebaseasinecosinetangentlogxtothebase10,commonlogarithmlogxtothebasee,naturallogarithmcotangentarcsinearccosine0.5 关于数学符号和数学式关于数学符号和数学式 Mathematic symbols and Expressions 0.5.2 常用数学式常用数学式 Mathematic Expressionsthesummationofxsubi,whereigoesfrom1tontheproductofxsubi,whereigoes

52、from1tonthedifferentialcoefficientofywithrespecttox,thefirstderivativeofywithrespecttox thenthderivativeofywithrespecttox 0.5 关于数学符号和数学式关于数学符号和数学式 Mathematic symbols and Expressions 0.5.2 常用数学式常用数学式 Mathematic Expressionsthepartialderivativeofywithrespectofu,whereyisafunctionofuandanothervariable(s)

53、integralofdoubleintegralofn-foldintegralofintegralbetweenlimitsaandb(.fromatob)0.5 关于数学符号和数学式关于数学符号和数学式 Mathematic symbols and Expressions 0.5.2 常用数学式常用数学式 Mathematic Expressionsfactorialntheabsolutevalueofxthemeanvalueofx , x barx primefunctionf of x 0.5 关于数学符号和数学式关于数学符号和数学式 Mathematic symbols and

54、Expressions integerdecimalfractionrationalnumberirrationalnumberrealnumberimaginarynumberpositivenumbernegativenumbercomplexnumbersingularnumberpluralnumberevennumberoddnumberprimenumberbasenumberrandomnumbern-digitnumber0.5.2 常用数学式常用数学式 Mathematic Expressions0.5 关于数学符号和数学式关于数学符号和数学式 Mathematic symb

55、ols and Expressions 0.5.2 常用数学式常用数学式 Mathematic Expressionsfunctionequationinequalityexpressionformulavariable(IV:independentDV:dependent)constantparametercoefficientfactor0.6 关于图、表关于图、表 Figures and Tables 0.6.1 图图 Figuresv图的编号图的编号Figure1,Figure2,对于较短的文章，可将所有图按顺序统一编号如：Fig.1,Fig.2,对于较长的文章，可将所有图分章节编号如

56、：Figure1-1,Figure1-2,Figure2-1,Figure2-2Fig.1-1,Fig.1-2,Fig.2-1,Fig.2-20.6 关于图、表关于图、表 Figures and Tables 0.6.1 图图 Figuresv图的来源图的来源Fig.1theAT&Ttelephonehierarchy.(Source:AndrewS.Tandenbaum.ComputerNetworks)如果图是自己创作的，可不作说明，如果是引自其它文献，则有必要在图旁或题后注明来源：0.6 关于图、表关于图、表 Figures and Tables 0.6.1 图图 Figuresbloc

57、kdiagramschematicdiagramcircuitdiagramconnectiondiagramwiringdiagramphasediagramstatediagramsignalstatediagramVenndiagramv与图有关的表达用语与图有关的表达用语方框图示意图原理图电路图线路图连接图接线图布线图相位图状态图信号状态图维恩图文氏图0.6 关于图、表关于图、表 Figures and Tables 0.6.1 图图 Figuresv与图有关的表达用语与图有关的表达用语linegraphcurvelinegraphbrokenlinegraphbargraphstat

58、isticalchart/diagramflowchartdiagrammaticsketchVectogramhistogram线图曲线图折线图条形图统计图表流程图示意图略图矢量图向量图直方图柱状图0.6 关于图、表关于图、表 Figures and Tables 0.6.1 图图 Figuresv与图有关的表达用语与图有关的表达用语SomethingmaybedescribedbytheblockdiagramshowninFigure1-1.Figure6-1illustratestherelationshipamongA,BandC.Figure14-1showsasimplified

59、blockdiagramofsomething.ThescanningprocedureisillustratedinFigure2-1.0.6 关于图、表关于图、表 Figures and Tables 0.6.1 图图 Figuresv与图有关的表达用语与图有关的表达用语InFigure2-2,Asthefigureshows,asillustratedinFigure2-2.Intheanalogworld,imagesareusuallypresentedashorizontalrasterlines(seeFigure14-2).0.6 关于图、表关于图、表 Figures and

60、Tables 0.6.2 表表 Tablesv 表的编号表的编号Table1,Table2,类似于图的编号如：Tab.1,Tab.2,Table1-1,Table1-2,Tab.1-1,Tab.1-2,0.6 关于图、表关于图、表 Figures and Tables 0.6.2 表表 Tablesv表的来源表的来源类似于图的来源Tab.1AcomparisonofsemiconductordiodesandLEDsaslightsources(Source:AndrewS.Tandenbaum.ComputerNetworks)0.7 专业英文写作专业英文写作 Writing 0.7.1 英

61、文科技论文的体例英文科技论文的体例 the Style v长篇科技报告长篇科技报告 FRONT前部FrontcoverTitlepageLetteroftransmittalDistributionlistPrefaceorforewordAcknowledgmentAbstractTableofcontentsListofillustration0.7 专业英文写作专业英文写作 Writing 0.7.1 英文科技论文的体例英文科技论文的体例 the Stylev长篇科技报告长篇科技报告 MAINTEXT正文IntroductionExperimentalprocedureandresult

62、swithsubheadingsDiscussionConclusionRecommendations0.7 专业英文写作专业英文写作 Writing 0.7.1 英文科技论文的体例英文科技论文的体例 the Stylev长篇科技报告长篇科技报告 BACK后部ListofreferencesAppendicesTablesGraphicsListofabbreviations,signsandsymbolsIndexBackcover0.7 专业英文写作专业英文写作 Writing 0.7.1 英文科技论文的体例英文科技论文的体例 the Stylev长篇科技报告长篇科技报告 其中，通常fro

63、ntcover封面又包括：ThetitleContractorjobnumberTheauthororauthorsDateofissueReportnumberandserialnumberNameoforganizationresponsibleforthereportAclassificationnotice密级0.7 专业英文写作专业英文写作 Writing 0.7.1 英文科技论文的体例英文科技论文的体例 the Stylev期刊类科技论文期刊类科技论文 TitleAbstractKeywordsIntroductionTest(Experimental)procedureResul

64、tsDiscussionsAcknowledgmentsReferences0.7 专业英文写作专业英文写作 Writing 0.7.2 论文的标题论文的标题 the Titlev简短精炼，概况性强，能鲜明的概括论文的主题。简短精炼，概况性强，能鲜明的概括论文的主题。常用词：常用词：study, research, design, implementation, analysis, applications, algorithm, approach, scheme, comparison, introduction 通常采用名词、名词词组或名词短语，避免通常采用名词、名词词组或名词短语，避免使

65、用句子。使用句子。0.7 专业英文写作专业英文写作 Writing 0.7.2 论文的标题论文的标题 the Titlev简短精炼，概况性强，能鲜明的概括论文的主题。简短精炼，概况性强，能鲜明的概括论文的主题。HIERARCHICAL SERVICE CONTROL SCHEME FOR INTELLIGENT NETWORK SERVICE Current studies and future prospects on asynchronous transfer mode 常用格式有三种：全大写，单词首字母大写，常用格式有三种：全大写，单词首字母大写，首字母大写首字母大写 （参见上例）（参见

66、上例） A Baseband Residual Vector Quantization Algorithm for Voiceband Data Signal0.7 专业英文写作专业英文写作 Writing 0.7.3 论文的摘要论文的摘要 the Abstractv摘要，是对原文的高度概括，能脱离原文而独立摘要，是对原文的高度概括，能脱离原文而独立存在。存在。一般包括如下内容：一般包括如下内容： 研究的目的与意义研究的目的与意义 研究的方法与途径研究的方法与途径 研究的成果与结论研究的成果与结论摘要，利于读者概要地了解论文的主要内容，利于编目检索。0.7 专业英文写作专业英文写作 Writi

67、ng 0.7.3 论文的摘要论文的摘要 the Abstract摘要的写作风格同正文（见摘要的写作风格同正文（见0.1科技英语的特点）。科技英语的特点）。 开门见山的点明主题开门见山的点明主题 简要列举主要工作及成果简要列举主要工作及成果 强调新思想及特点强调新思想及特点 采用第三人称和现在时采用第三人称和现在时 多用被动态多用被动态v摘要，是对原文的高度概括，能脱离原文而独立摘要，是对原文的高度概括，能脱离原文而独立存在。存在。AdesignforageneralpurposeVLSIfrequen-cysynthesizeris presented.It is shown thatasim

68、plebasicdesigncanhaveafullyprofessionalperformance.SomeofthespecialrequirementsplacedontheVLSItechnologyare discussed.0.7 专业英文写作专业英文写作 Writing 0.7.3 论文的摘要论文的摘要 the Abstractve.g. Abstract:A General Purpose VLSI Frequency Synthesis SystemKey words: generalpurpose;VLSI;frequencysynthesis the authors in

69、troduceanewapproachfortrafficcharacterisationinATMnetworks.This is based on the study ofremotequantilesassociatedwithstationarypointprocessesasfunctionsoftimeinterval.It is shown thatusefulinformationaboutthemeanandvariabilityoftheprocesscanbeextractedfromtheasymptoticbehavior.Finally, the authors s

70、howtheuseofsuchtimequantilesinthecontextofqueuedimen-sioningwhichallowscomparisonoftheblockingbehavioroftrafficstreamswithoutdetailedcalculations.0.7 专业英文写作专业英文写作 Writing 0.7.3 论文的摘要论文的摘要 the Abstractve.g. Abstract:New approach for traffic characterisation in ATM network0.7 专业英文写作专业英文写作 Writing 0.7.

71、3 论文的摘要论文的摘要 the Abstractve.g. Key words: ATMnetwork,queuedimensioning,remotequantiles,trafficcharacterisation 0.7 专业英文写作专业英文写作 Writing 0.7.4 论文的参考文献论文的参考文献 References v在论文中，凡是引用或参考他人文献的数据、资在论文中，凡是引用或参考他人文献的数据、资料、观点、方法和研究成果的地方，都应该标明料、观点、方法和研究成果的地方，都应该标明出处，对应的在参考文献中列出。出处，对应的在参考文献中列出。 体现对他人劳动、研究成果的尊重，

72、反映作者体现对他人劳动、研究成果的尊重，反映作者严谨的科学态度和研究工作的科学依据；严谨的科学态度和研究工作的科学依据； 便于读者追溯有关原始文献，进一步查阅参考便于读者追溯有关原始文献，进一步查阅参考文献。文献。0.7 专业英文写作专业英文写作 Writing 0.7.4 论文的参考文献论文的参考文献 References v参考文献著录格式参考文献著录格式 在正文中在正文中引用参考文献的标注方法：一般采用顺引用参考文献的标注方法：一般采用顺序编号法。即在引用文字的右上角标注序号，按在文序编号法。即在引用文字的右上角标注序号，按在文章中出现的顺序进行编号。章中出现的顺序进行编号。 在文后参考

73、文献中在文后参考文献中所列的文献顺序应与正文中编所列的文献顺序应与正文中编号一致。号一致。0.7 专业英文写作专业英文写作 Writing 0.7.4 论文的参考文献论文的参考文献 References 按国际标准，参考文献的著录格式分为按国际标准，参考文献的著录格式分为3部分：部分： 作者姓名作者姓名. 文献题名文献题名. 出版事项出版事项1 戴明桢戴明桢. 数字信号处理的硬件实现数字信号处理的硬件实现M. 北京：航空北京：航空 工业出版社工业出版社, 1998. 12-15序号序号 作者姓名作者姓名. 文献题名文献题名文献类型标识文献类型标识. 出版地出版地: 出版社，出版年出版社，出版年

74、. 起止页码起止页码(任选任选) 对于专著、论文集、学位论文、报告，具体格式为：对于专著、论文集、学位论文、报告，具体格式为： v参考文献著录格式参考文献著录格式14 Stephen G. Wilson. Digital Modulation and Coding M. Prentice Hall. 19960.7 专业英文写作专业英文写作 Writing 0.7.4 论文的参考文献论文的参考文献 References 6 金显贺，王昌长，王忠东，等金显贺，王昌长，王忠东，等. 一种用于在线检测一种用于在线检测 局部放电的数字滤波技术局部放电的数字滤波技术J. 清华大学学报清华大学学报(自然自

75、然 科学版科学版)，1993，33(4): 62-67 对于期刊文章，具体格式为：对于期刊文章，具体格式为： 序号序号 作者姓名作者姓名. 文献题名文献题名J. 刊名刊名,年年,卷卷(期期):起止页码起止页码 v参考文献著录格式参考文献著录格式9 Tekinay, S. and Jabbari, B. Handover and channel assignment in mobile cellular networks. IEEE Com- munication Magazine, 1991, 29(11): 42-460.7 专业英文写作专业英文写作 Writing 0.7.4 论文的参考文

76、献论文的参考文献 References 专著专著 M 论文集论文集 C 报刊文章报刊文章 N期刊文章期刊文章 J 学位论文学位论文 D 报告报告 R专著或论文集中析出的文献专著或论文集中析出的文献 A 对于其他未说明的文献类型对于其他未说明的文献类型 Z v参考文献著录格式参考文献著录格式其中其中文献类型标识文献类型标识规定规定光盘图书光盘图书 M/CD网上电子公告网上电子公告 EB/OL网上期刊网上期刊 J/OL对于电子类型的参考文献，常用的有：对于电子类型的参考文献，常用的有：网上数据库网上数据库 DB/OL0.7 专业英文写作专业英文写作 Writing 0.7.4 论文的参考文献论文的

77、参考文献 References v参考文献著录格式参考文献著录格式8 谢希德.创造学习的新思路N.人民日报，1998- 12-25(10) 11 王明亮. 关于中国学术期刊标准化数据库系统工 程的进展EB/OL. http:/ pub /wml.txt/980810-2.html1998-08-16/1998- 10-040.7 专业英文写作专业英文写作 Writing 0.7.5 写作常用句型写作常用句型 Sentence Patternsv(1) In this paper, . is(are)presented(described, discussed, investigated, st

78、udied).v(2) This paper (article, thesis) focuses on(presents, describes, discusses)v(3) The purpose (aim, objective, attempt) of this paper is to .v(4) The approach is based on .v(5) Conditions are considered for .v(6) The requirement for .0.7 专业英文写作专业英文写作 Writing 0.7.5 写作常用句型写作常用句型 Sentence Pattern

79、sv(7) The simulation is performed by using .v(8) This method is confirmed experimentally with .v(9) The result of this study can be summarized for .v(10) Results forare found to be close to the experimental datav(11) This paper demonstrates .v(12) The analysis of this study illustrates .0.7 专业英文写作专业

80、英文写作 Writing 0.7.5 写作常用句型写作常用句型 Sentence Patterns并作如下补充：并作如下补充：v摘要写作：摘要写作：0.7 专业英文写作专业英文写作 Writing 0.7.5 写作常用句型写作常用句型 Sentence Patternsv摘要写作：摘要写作：0.7 专业英文写作专业英文写作 Writing 0.7.5 写作常用句型写作常用句型 Sentence Patternsv摘要写作：摘要写作：This paper aims to v0.7 专业英文写作专业英文写作 Writing 0.7.5 写作常用句型写作常用句型 Sentence Patternsv

81、摘要写作：摘要写作：0.7 专业英文写作专业英文写作 Writing 0.7.5 写作常用句型写作常用句型 Sentence Patternsv摘要写作：摘要写作：0.7 专业英文写作专业英文写作 Writing 0.7.5 写作常用句型写作常用句型 Sentence Patternsv摘要写作：摘要写作：0.7 专业英文写作专业英文写作 Writing 0.7.5 写作常用句型写作常用句型 Sentence Patternsv正文写作：正文写作：0.7 专业英文写作专业英文写作 Writing 0.7.5 写作常用句型写作常用句型 Sentence Patternsv正文写作正文写作定义、描

82、述定义、描述 define take(4) consider describe refer to. as .0.7 专业英文写作专业英文写作 Writing 0.7.5 写作常用句型写作常用句型 Sentence Patternsv正文写作正文写作假说、假设：假说、假设：(1)(2)0.7 专业英文写作专业英文写作 Writing 0.7.5 写作常用句型写作常用句型 Sentence Patternsv摘要写作：摘要写作：(3)v正文写作正文写作假说、假设：假说、假设：0.7 专业英文写作专业英文写作 Writing 0.7.5 写作常用句型写作常用句型 Sentence Patterns(

83、4)v正文写作正文写作假说、假设：假说、假设：0.7 专业英文写作专业英文写作 Writing 0.7.5 写作常用句型写作常用句型 Sentence Patterns(1)v正文写作正文写作分类：分类：0.7 专业英文写作专业英文写作 Writing 0.7.5 写作常用句型写作常用句型 Sentence Patterns(2)v正文写作正文写作分类：分类：0.7 专业英文写作专业英文写作 Writing 0.7.5 写作常用句型写作常用句型 Sentence Patternsv结语写作：结语写作：0.7 专业英文写作专业英文写作 Writing 0.7.5 写作常用句型写作常用句型 Sen

84、tence Patternsv结语写作：结语写作：0.7 专业英文写作专业英文写作 Writing 0.7.5 写作常用句型写作常用句型 Sentence Patternsv结语写作：结语写作：0.7 专业英文写作专业英文写作 Writing 0.7.6 写作练习写作练习 ExercisesLesson 1 电子通信简介电子通信简介Introduction to Electronic Communication (UNIT 6 Passage A ) Intensive reading：1. 2.v内容大纲内容大纲 Outline：Lesson 1 电子通信简介电子通信简介Introducti

85、on to Electronic Communication 1.1 Historical PerspectiveAtimechartshowingthehistoricaldevelopmentsAllcommunicationssystemsinvolvesthreemainsubsystems:transmitter , receiver , channel .1.2 Electronic Communications Systemsv内容大纲内容大纲 Outline：Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communicatio

86、n 1.3 The Electromagnetic Spectrum1.4 Bandwidth and Information CapacityAcommunicationsystemisstronglydependentonitsoperatingfrequencyband.Aspectrumtableshowstheelectromagneticwavebands.Hartleys law :I = B tShannons formula :v精读详解精读详解 Intensive reading：Lesson 1 电子通信简介电子通信简介Introduction to Electronic

87、 Communication Thefundamentalpurposeofanelectroniccommunicationsystemsistotransferinformationfromoneplacetoanother.Thus,electroniccommunicationscanbesummarizedasthetransmission,reception,andprocessingofinformationbetweentwoormorelocationsusingelectroniccircuits. 1.1 Historical Perspectivegeneral pur

88、pose 通用通用special purpose 专用专用 multi-purpose 多用，万用的多用，万用的v精读详解精读详解 Intensive reading：Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communication The original source informationcanbeinanalog(continuous)form,suchasthehumanvoiceormusic,orindigital(discrete)form,suchasbinary-codednumbersoralphanumericc

89、odes.Allformsofinformation,however,mustbeconvertedtoelectromagneticenergybeforebeingpropagatedthroughanelectroniccommunicationssystem.v精读详解精读详解 Intensive reading：Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communication Samuel Morsedevelopedthefirstelectroniccommunicationssystemin1837.Morseusede

90、lectromagneticinductiontotransferinformationintheformofdots,dashes,andspacesbetweenasimpletransmitterandreceiverusingatransmissionlineconsistingofalengthofmetallicwire.Hecalledhisinventionthe telegraph .v精读详解精读详解 Intensive reading：Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communication v精读详解精读

91、详解 Intensive reading：Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communication In1876Alexander Graham BellandThomas A. Watsonwerethefirsttosuccessfullytransferhumanconversationoveracrudemetallic-wirecommunicationssystemtheycalledthetelephone.Alexander Graham Bell (American 1847 1922 )v精读详解精读详解 I

92、ntensive reading：Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communication Guglielmo Marconisuccessfullytransmittedthefirstwireless radio signalsthroughearthsatmospherein1894,andin1908Lee DeForestinventedthetriode vacuum tubewhichprovidedthefirstpracticalmeansofamplifyingelectricalsignals.v精读详解精

93、读详解 Intensive reading：Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communication GuglielmoMarconi(Italian18741937)LeeDeForest(American18731961)v精读详解精读详解 Intensive reading：Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communication Althoughthe fundamental concepts andprinciplesofelectroniccommun

94、icationshavechangedlittlesincetheirinception,themethodsandcircuits usedtoimplementthemhaveundergoneconsiderablechange.Inrecentyears,transistors andlinear integrated circuitshavesimplifiedthedesignofelectroniccommunicationscircuits,thusallowingforminiaturiza-tion,improvedperformanceandreliability,and

95、reducedoverallcosts.v精读详解精读详解 Intensive reading：Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communication Modern electroniccommunicationssystemsincludemetalliccablesystems,microwaveandsatelliteradiosystems,andopticalfibersystems.Atime chartshowingthehistoricaldevelopmentofcommunicationsisgivenin

96、Table6.1.v精读详解精读详解 Intensive reading：Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communication CommunicationsSystemsmaybedescribedbytheblockdiagramshowninFigure6.1.1.2 Electronic Communications SystemsRegardlessoftheparticularapplication,allcommunicationssystemsinvolvethree main sub-systems:thet

97、ransmitter,thechannel,andthereceiver.The messagefromthesourceisrepresentedbytheinformationinputwaveformm(t).Themessagedeliver-edtothesinkisdenotedby.Theindicatesthatthemessagereceivedmaynotbethesameasthattransmitted.v精读详解精读详解 Intensive reading：Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communic

98、ation Thatisthemessageatthesinkmaybecorruptedbynoiseinthechannelortheremaybeotherimpairmentsinthesystem,suchasundesiredfilteringorundesirednonlinearities.v精读详解精读详解 Intensive reading：Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communication Thespectra(orfrequencies)ofm(t)andareconcentratedaboutf=

99、0;consequently,theyaresaidtobebaseband signals. sing. pl.spectrum spectra 频谱datum data 数据medium media 媒质、媒体Inmultiplexed systems,theremaybemultipleinputandoutputmessagesourcesandsinks.v精读详解精读详解 Intensive reading：Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communication multiplex a. v. 复用，多路复用，多路

100、传输multiple a.多数的，多倍的，多路的，复接 n.倍数Inananalog system,thesignalprocessormaybeananaloglow-passfilterthatisusedtorestrictthebandwidthofm(t).v精读详解精读详解 Intensive reading：Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communication Inahybridsystem,thesignalprocessormaybeananalog-to-digitalconverter(ADC).Int

101、hiscase,theADCinthesignalprocessorisprovidingsourcecodingoftheinputsignal.signal processorlow-pass filter 低通滤波器band-pass filter 带通滤波器high-pass filter 高通滤波器band-stop filter 带阻滤波器analog digital hybridrestrict the bandwidth 限制带宽Inaddition,thesignalprocessormayalsoaddparitybitstothedigitalwordtoprovidec

102、hannelcodingsothaterrordetectionandcorrectioncanbeusedbythesignalprocessorinthereceivertoreduceoreliminatebiterrorsthatarecausedbynoiseinthechannel.v精读详解精读详解 Intensive reading：Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communication signal processorsource coding 信源编码channel coding 信道编码error det

103、ection 检错，误差检测error correction 纠错，误差校正bit error 误码，位差错bit error rate/ratio 误码率add parity bits to the digital word为数码字加入校验位reduce or eliminate bit errors减少或消除误码Thetransmittercarriercircuitconvertstheprocessedbasebandsignalintoafrequencybandthatisappropriateforthetransmissionmediumofthechannel.v精读详解精读

104、详解 Intensive reading：Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communication Forexample,ifthechannelconsistsofafiberopticcable,thecarriercircuitsconvertthebasebandinputtolightfrequencies,andthetransmittedsignals(t)islight.carrier circuitbaseband 基带 f0frequency band 频带 fc0convert A to / into Bv

105、精读详解精读详解 Intensive reading：Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communication Forexample,anamplitudemodulated(AM)broadcastingstationwithanassignedfrequencyof850kHzhasacarrierfrequencyoffc=850kHz.Themapping ofthebasebandinputinformationwaveformm(t)intothebandpasssignals(t)iscalledmodulatio

106、n.carrier circuitmap 映射，变换，测绘the mapping of A into B 从A到B的映射onetomany mapping 一对多映射map A into B 将A映射到BA be said to be BA be called B A被称作BA be referred to as Bv精读详解精读详解 Intensive reading：Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communication Incommunicationsystemsthatusetheatmosphereforthetra

107、nsmissionchannel,interferenceandpropagationconditionsarestronglydependentonthetransmissionfrequency.Theoretically,anytypeofmodulation(e.g.,amplitude modulation, frequency modulation, single sideband, phase-shift keying, frequency-shift keying,etc.)couldbeusedatanytransmissionfrequency. 1.3 The Elect

108、romagnetic Spectrumv精读详解精读详解 Intensive reading：Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communication However,toprovidesomesemblanceoforderandforpoliticalreasons,governmentregulationsspecifythemodulationtype,bandwidth,andtypeofinformationthatcanbetransmittedoverdesignedfrequencybands.Onaninte

109、rnationalbasis,frequencyassignmentsandtechnicalstandardsaresetbytheInternational Telecommunications Union (ITU).TheITUisaspecializedagencyoftheUnitedNations， 1.3 The Electromagnetic Spectrum before1992 CCITT CCIRLesson 1 电子通信简介电子通信简介Introduction to Electronic Communication ITUafter 1992 ITU-R ITU-T

110、ITU-DITU：International Telecommunications Union 国际电信联盟v精读详解精读详解 Intensive reading： 1.3 The Electromagnetic SpectrumLesson 1 电子通信简介电子通信简介Introduction to Electronic Communication v精读详解精读详解 Intensive reading： 1.3 The Electromagnetic SpectrumTable6.2givesagenerallistingoffrequencybands.Theircommondesign

111、ations,typicalpropagationconditions,andtypicalservicesassignedtothesebands.Fequency BandsELF 极低频极低频 extremely ULF 特低频特低频 ultra VLF 甚低频甚低频 very LF 低频低频 low frequencyMF 中频中频 medium frequencyHF 高频高频 high frequencyVHF 甚高频甚高频 vey UHF 特高频特高频 ultra SHF 超高频超高频 super EHF 极高频极高频 extremely Infrared , visible l

112、ight , ultravioletLesson 1 电子通信简介电子通信简介Introduction to Electronic Communication Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communication v精读详解精读详解 Intensive reading：Information theoryisahighlytheoreticalstudyoftheefficientuseofbandwidthtopropagateinformationthroughelectroniccommunicationssystem

113、s.Informationtheorycanbeusedtodeterminetheinformationcapacityofacommunicationssystem.Informationcapacityisameasureofhowmuchinformationcanbetransferredthroughacommunica-tionssysteminagivenperiodoftime.1.4 Bandwidth and Information CapacityLesson 1 电子通信简介电子通信简介Introduction to Electronic Communication

114、v精读详解精读详解 Intensive reading：Mathematically,Hartleys lawisstatedasIBt,whereI=informationcapacity,B=systembandwidth(Hz),t=transmissiontime(second).Thisequationshowsthatinformationcapacityisalinearfunctionanddirectlyproportionaltobothsystembandwidthandtransmissiontime.1.4 Bandwidth and Information Capa

115、cityLesson 1 电子通信简介电子通信简介Introduction to Electronic Communication v精读详解精读详解 Intensive reading：In1948,C. E. Shannon(alsoofBellTelephoneLaboratories)publishedapaperintheBellSystemTechnicalJournalrelatingtheinformationcapacityofacommunicationschannelinbits-per-second(bps)tobandwidthandsignal-to-noisera

116、tio.Mathematicallystated,theShannonlimitforinformationcapacityis1.4 Bandwidth and Information CapacitywhereI=informationcapacity(bps),B=bandwidth(Hz),S/N=signal-to-noisepowerratio(unit-less).v补充材料补充材料Supplementary materials: PCMPCM:PulseCodeModulation脉冲编码调制PCMisdependentonthreeseparateoperations:sam

117、pling, quantizing, and coding.Lesson 1 电子通信简介电子通信简介Introduction to Electronic Communication Figure6.2illustratesthesampling,quantizing,andcodingprocesses.v补充材料补充材料PCMsamplingLesson 1 电子通信简介电子通信简介Introduction to Electronic Communication v补充材料补充材料PCMcodingquantizing，v补充材料补充材料PCMLesson 1 电子通信简介电子通信简介In

118、troduction to Electronic Communication v补充材料补充材料PCMAdigitaltransmissionsystemusedforPCMtransmissionsamplerreconstruction filterA/DD/AdigitaltransmissionsystemLesson 1 电子通信简介电子通信简介Introduction to Electronic Communication Lesson 2 数字调制数字调制 Digital Modulation (UNIT 7 Passage A ) Intensive reading：1. 2.

119、Lesson 2 数字调制数字调制 Digital ModulationModulationv技术背景技术背景 Background： the process of impressing low-frequency information signals onto a high-frequency carrier signal Demodulation the reverse process载波调制carrier（continuous wave） modulation脉冲调制pulse modulation调制方式用途举例载波调制（连续波调制）线性调制常规双边带调制AM广播单边带调制SSB载波

120、通信、短波无线电话通信双边带调制DSB立体声广播残留边带调制VSB电视广播、传真非线性调制频率调制FM微波中继、卫星通信、广播相位调制PM中间调制方式数字调制振幅键控ASK数据传输频移键控FSK数据传输相移键控PSK、DPSK 数据传输其他高效数字调制QAM、MSK等数字微波、空间通信Modulation Methods (carrier modulation)调制方式用途举例脉冲调制脉冲模拟调制脉幅调制PAM中间调制方式、遥测脉宽调制PDM中间调制方式脉位调制PPM遥测、光纤传输脉冲数字调制脉码调制PCM实话中继线、卫星、空间通信增量调制M军用、民用数字电话差分脉码调制DPCM电视电话、图像

121、编码其他编码方式ADPCM等中速数字电话Modulation Methods (pulse modulation) 1. IntroductionModerncommunicationsystemsusedigitalmodulationtechniques.Advancementsinvery large integration (VLSI)anddigital signal processing (DSP)technologyhavemadedigitalmodulationlesscostthananalogtransmissionsystems.Digitalmodulationoff

122、ersmanyadvantagesoveranalogmodulation.Lesson 2 数字调制数字调制 Digital Modulationv精读详解精读详解 Intensive reading：Someadvantagesincludegreaternoiseimmunityandrobustnesstochannelimpairments,easiermultiplexingofvariousformsofinformation(e.g.,voice,data,andvideo),andgreatersecurity.Furthermore,digitaltransmissions

123、accommodatedigitalerror-controlcodesthat detectand/orcorrecttransmissionerrors,andsupportcomplexsignalconditioningandprocessingtechniquessuchassourcecoding,encryption,andequalizationtoimprovetheperformanceoftheoverallcommunicationlink.Lesson 2 数字调制数字调制 Digital Modulationv精读详解精读详解 Intensive reading：N

124、ewmultipurpose programmable digital signal processorshavemadeitpossibletoimplementdigitalmodulatorsanddemodulatorscompletelyinsoftware.Insteadofhavingaparticularmoderndesignpermanentlyfrozenashardware,embeddedsoftwareimplementationsnowallowalterationsandimprovementswithouthavingtoredesignorreplaceth

125、emodem.Lesson 2 数字调制数字调制 Digital Modulationv精读详解精读详解 Intensive reading：Advantages:greater noise immunityeasier multiplexing greater securitydigital error-control codescomplex signal conditioning and processing techniquessoftware implementations and easier alterations and improvements Indigitalcommun

126、icationsystems,themodulating signal(e.g.,message)mayberepresentedasatimesequenceofsymbolsorpulses,whereeachsymbolhasmfinitestates.Eachsymbolrepresentsnbitsofinformation,wheren=log2mbits/symbol.Manydigital modulation schemesareusedinmoderncommunicationsystems,andmoreandmorearesuretobeintroduced.Someo

127、fthesetechniqueshavesubtledifferencesbetweenoneanother,andeachtechniquebelongstoafamilyofrelatedmodulationmethods.Lesson 2 数字调制数字调制 Digital Modulationv精读详解精读详解 Intensive reading：2. Factors That Influence the Choice of Digital ModulationSeveralfactorsinfluencethechoiceofadigitalmodulationscheme.Adesi

128、rable modulation schemeprovideslowbiterrorratesatlowreceivedsignal-to-noiseratios,performswellinmultipathandfadingconditions,occupiesaminimumofbandwidth,andiseasyandcost-effectivetoimplement.Existing modulation schemesdonotsimultaneouslysatisfyalloftheserequirements.Lesson 2 数字调制数字调制 Digital Modulat

129、ionv精读详解精读详解 Intensive reading：Somemodulationschemesarebetterintermsofthebiterrorrateperformance,whileothersarebetterintermsofbandwidthefficiency.Dependingonthedemandsoftheparticularapplication, tradeoffsaremadewhenselectionadigitalmodulation.Lesson 2 数字调制数字调制 Digital Modulationv精读详解精读详解 Intensive r

130、eading：make a tradeoff between A and Bmake a tradeoff among these parameters Bandwidth efficiencydescribestheabilityofamodulationschemetoaccommodatedatawithinalimitedbandwidth. Lesson 2 数字调制数字调制 Digital Modulationv精读详解精读详解 Intensive reading：Theperformanceofamodulationschemesisoftenmeasuredintermsofi

131、tspowerefficiencyandbandwidthefficiency.Power efficiencydescribestheabilityofamodulationtechniquetopreservethefidelityofthedigitalmessageatlowpowerlevels. andisoftenexpressedastheratioofthesignalenergyperbittonoisepowerspectraldensity(Eb/No)requiredatthereceiverinputforacertainprobabilityoferror(say

132、10-5).Lesson 2 数字调制数字调制 Digital Modulationv精读详解精读详解 Intensive reading：Whilepowerandbandwidthefficiencyconsiderationsareveryimportant,other factorsalsoaffectthechoiceofadigitalmodulationschemes.Forexample,forallpersonalcommunicationsystemswhichservealargeusercommunity,thecostandcomplexityofthesubscri

133、berreceivermustbeminimized,andamodulationwhichissimpletodetectismostattractive.TheperformanceofthemodulationschemeundervarioustypesofchannelimpairmentssuchasRayleighandRiceanfadingandmultipathtimedispersion,givenaparticulardemodulatorimplementation,isanotherkeyfactorinselectingamodulation.Factors:po

134、wer efficiencybandwidth efficiencythe cost and complexitysimplification the performance under various types of channel impairments Amplitude Modulation (AM) the process of changing the amplitude of a relatively high frequency carrier signal in proportion with the instantaneous value of the modulatin

135、g signal (information) .DSBFC Double-sideband full carrier 双边带全载波调制双边带全载波调制Lesson 2 数字调制数字调制 Digital Modulationv补充材料补充材料Supplementary materials: AM AM modulatorsarenonlineardeviceswithtwoinputsandoneoutput.Oneinputisasingle,high-frequencycarriersignalofconstantamplitudeandthesecondinputiscomprisedof

136、relativelylow-frequencyinformationsignalswhichmaybesinglefrequencyoracomplexwaveformmadeupofmanyfrequencies.Lesson 2 数字调制数字调制 Digital Modulationv补充材料补充材料Supplementary materials: AMFrequenciesthatarehighenoughtobeefficientlyradiatedbyanantennaandpropagatedthroughfreespacearecommonlycalledradiofrequen

137、cies,orsimplyRFs.Typicalvoice-gradecommunicationssystemsutilizearangeofinformationfrequenciesbetween300Hzand3000Hz.Lesson 2 数字调制数字调制 Digital Modulationv补充材料补充材料Supplementary materials: AMThemodulatedoutputwaveformfromanAMmodulatorisoftencalledanAM envelope .Althoughthereareseveraltypesofamplitudemod

138、ulation,AMdouble-sidebandfullcarrier(DSBFC)isprobablythemostcommonlyused.AMDSBFCissometimescalledconventionalAMorsimplyAM.The AM EnvelopeLesson 2 数字调制数字调制 Digital Modulationv补充材料补充材料Supplementary materials: AMLesson 6 幅度调制传输幅度调制传输 Amplitude Modulation Transmission v精读详解精读详解 Intensive reading：调制信号载波已

139、调波FigureX-1illustratestherelationshipamongthecarrier,themodulatingsignal,andthemodulatedwaveforconventionalAM.ThefigureshowshowanAMwaveformisproducedwhenasinglefrequencymodulatingsignalactsonahigh-frequencycarriersignal.Lesson 2 数字调制数字调制 Digital Modulationv补充材料补充材料Supplementary materials: AMWhenamod

140、ulatingsignalisapplied,theamplitudeoftheoutputwavevariesinaccordancewiththemodulatingsignal.Notethattherepetitionrateoftheenvelopeisequaltothefrequencyofthemodulatingsignal,andtheshapeoftheenvelopeisidenticaltotheshapeofthemodulatingsignal.Lesson 2 数字调制数字调制 Digital Modulationv补充材料补充材料Supplementary m

141、aterials: AMAnAMmodulatorisanonlineardevice.Therefore,nonlinearmixing occursandtheoutputenvelopeisacomplexwavemadeupofadcvoltage,thecarrierfrequency,andthesumanddifference frequencies(i.e.,thecrossproducts).AM Frequency Spectrum and BandwidthLesson 2 数字调制数字调制 Digital Modulationv补充材料补充材料Supplementary

142、 materials: AMlower sideband 下边带 LSBupper sideband 上边带 USBlower side frequencies 下边频LSFupper side frequencies 上边频USFLesson 2 数字调制数字调制 Digital Modulationv补充材料补充材料Supplementary materials: AMAnAMsignalspectrumcontainsfrequency componentsspacedHzoneithersideofthecarrier.However,itshouldbenotedthatthemod

143、ulatedwavedoesnotcontainafrequencycomponentthatisequaltothemodulatingsignalfrequency.Theeffectofmodulationistotranslatethemodulatingsignalinthefrequencydomainsothatitisreflectedsymmetricallyaboutthecarrierfrequency.Lesson 2 数字调制数字调制 Digital Modulationv补充材料补充材料Supplementary materials: AMThebandwidth

144、(B)ofanAMDSBFCwaveisequaltothe difference betweenthehighestuppersidefrequencyandthelowestsidefrequency,ortwotimesthehighestmodulatingsignalfrequency.Lesson 2 数字调制数字调制 Digital Modulationv补充材料补充材料Supplementary materials: AMLesson 3 电电 信信 Telecommunications (UNIT 8 Passage B ) Intensive reading：1. 2.Le

145、sson 3 电电 信信 Telecommunications v技术背景技术背景 Background：The four phases of the evolution of communications networks are shown in Table 8.1Lesson 3 电电 信信 Telecommunications v技术背景技术背景 Background：Lesson 3 电电 信信 Telecommunications v内容大纲内容大纲 Outline：Hardware and Software Hardware SoftwareApplications Host-T

146、erminal File-Transfer Computer-NetworkLesson 3 电电 信信 Telecommunications v内容大纲内容大纲 Outline：Telecommunication Services Network Information Retrieval Electronic Mail Bulletin BoardOngoing Developments prefaceLesson 3 电电 信信 Telecommunications Telecommunications are the transmission ofwords,sounds,images

147、,ordataintheformofelectronicorelectromagneticsignalsorimpulses.Transmissionmediaincludethetelephone(usingwireoropticalcable),radio,television,microwave,andsatellite.Datacommunication,thefastestgrowingfieldoftelecommunication,istheprocessoftransmittingdataindigitalformbywireorradio.v精读详解精读详解 Intensiv

148、e reading： prefaceLesson 3 电电 信信 Telecommunications Digital datacanbegenerateddirectlyina1/0binarycodebyacomputerorcanbeproducedfromavoiceorvisualsignalbyaprocesscalledencoding.A data communications networkiscreatedbyinterconnectingalargenumberofinformationsourcessothatdatacanflowfreelyamongthem.The

149、 datamay consist ofaspecificitemofinformation,agroupofsuchitems,orcomputerinstructions.Exampleincludeanewsitem,abanktransaction,amailingaddress,aletter,abook,amailinglist,abankstatement,oracomputerprogram.v精读详解精读详解 Intensive reading： prefaceLesson 3 电电 信信 Telecommunications The devices usedcanbecomp

150、uters,terminals(devicesthattransmitandreceiveinformation),andperipheralequipmentsuchasprinters.The transmission line usedcanbeanormaloraspeciallypurchasedtelephonelinecalledaleased,orprivateline.Itcanalsotaketheformofamicrowaveoracommunications-satellitelinkage,orsomecombinationofthesevarioussystems

151、.v精读详解精读详解 Intensive reading： Hardware and SoftwareLesson 3 电电 信信 Telecommunications Eachtelecommunications deviceuseshardware,whichconnectsadevicetothetransmissionline;andsoftware,whichmakesitpossibleforadevicetotransmitinformationthroughtheline.HardwareHardwareusuallyconsistsofatransmitterandacabl

152、einterface,orifthetelephoneisusedasatransmissionline,amodulator/demodulator,ormodem.v精读详解精读详解 Intensive reading： Hardware and SoftwareLesson 3 电电 信信 Telecommunications Acable interface,asthenameindicates,connectsadevicetoacable.Itconvertsthetransmittedsignalsfromtheformrequiredbythedevicetotheformre

153、quiredbythecable.v精读详解精读详解 Intensive reading： Hardware and SoftwareLesson 3 电电 信信 Telecommunications SoftwareAmongthedifferentkindsofsoftwarearefile-transfer,hostandnetworkprograms.File-transfersoftwareisusedtotransmitadatafilefromonedevicetoanother.Hostsoftwareidentifiesahostcomputerassuchandcontro

154、lstheflowofdataamongdevicesconnectedtoit.Networksoftwareallowsdevicesinacomputernetworktotransmitinformationtooneanother.v精读详解精读详解 Intensive reading： ApplicationsLesson 3 电电 信信 Telecommunications Host-TerminalInthesetypesofcommunications,one computerthe host computerisconnectedtooneormoreterminals.E

155、ach terminaltransmitsdatatoorreceivesdatafromthehostcomputer.Forexample,manyairlineshaveterminalsthatarelocatedatthedesksofticketagentsandconnectedtoacentral,hostcomputer.Theseterminalsobtainflightinformationfromthehostcomputer,whichmaybelocatedhundredsofkilometersawayfromtheagentssite. v精读详解精读详解 In

156、tensive reading： ApplicationsLesson 3 电电 信信 Telecommunications File-Transfer Anoutgrowthoffiletransferiselectronicmail.Forexample,anemployeemightwriteadocumentsuchasaletter,memorandum,orreportonacomputerandthensendthedocumenttoanotheremployeescomputer.v精读详解精读详解 Intensive reading： ApplicationsLesson

157、3 电电 信信 Telecommunications Computer-NetworkThethreekindsofcomputernetworksarelocalareanetworks(LAN),privatebranchexchange(PBX)networks,andwide-areanetworks(WAN).LANsinterconnectdeviceswithagroupofcables;thedevicescommunicateatahighspeedandmustbeincloseproximity.v精读详解精读详解 Intensive reading： Applicati

158、onsLesson 3 电电 信信 Telecommunications APBXnetworkinterconnectsdeviceswithatelephoneswitchingsystem;inthiskindofnetwork,thedevicesmustagainbeincloseproximity.Inwide-areanetworks,ontheotherhand,thedevicescanbeatgreatdistancesfromoneanother,andsuchnetworksusuallyinter-connectdevicesbymeansoftelephone.v精

159、读详解精读详解 Intensive reading： Telecommunication ServicesLesson 3 电电 信信 Telecommunications NetworkApublicnetworkserviceleasestimeonaWAN,therebyprovidingterminalsinothercitieswithaccesstoahostcomputer.ExamplesofsuchservicesincludeTelenet,Tymnet,Uninet,andDatapac.Theseservicessellthecomputingpowerofthehos

160、tcomputertouserswhocannotordonotwishtoinvestinthepurchaseofsuchequipment.v精读详解精读详解 Intensive reading： Telecommunication ServicesLesson 3 电电 信信 Telecommunications InformationRetrievalAninformation-retrievalservicesleasestimeonahostcomputertocustomerswhoseterminalsareusedtoretrievedatafromthehost.Anex

161、ampleofthisisCompuServe,whosehostcomputerisaccessedbymeansofthepublictelephonesystem.Thisandothersuchservicesprovidegeneral-purposeinformationonnews,weather,sports,finances,andshopping.v精读详解精读详解 Intensive reading： Telecommunication ServicesLesson 3 电电 信信 Telecommunications ElectronicMailBulletinBoar

162、dBymeansofabulletin board,terminalsareabletofacilitateexchangesandothertransactions.Manybulletinboardsdonotchargeafeefortheirservices.Usersoftheseservicessimplyexchangeinformationonhobbies,buyandsellgoodsandservices,andexchangecomputerprograms.v精读详解精读详解 Intensive reading： Ongoing DevelopmentsLesson

163、3 电电 信信 Telecommunications Certaintelecommunicationmethodshavebecomestandardinthetelecommunicationsindustryasawhole,becauseiftwodevicesusedifferentstandardstheyareunabletocommunicateproperly.Standards are developed in two ways:(1)themethodissowidelyusedthatitcomestodominate;(2)themethodispublishedby

164、astandard-settingorganization.v精读详解精读详解 Intensive reading： Ongoing DevelopmentsLesson 3 电电 信信 Telecommunications ThemostimportantorganizationinthisrespectistheInternationalTelecommunicationUnion,aspecializedagencyoftheUnitedNationsandoneofitsoperationalentities,theInternationalTelegraphandTelephoneC

165、onsultativeCommittee(CCITT).OtherorganizationsintheareaofstandardsaretheAmericanNationalStandardsInstitute(ANSI),theInstituteofElectricalEngineers(IEE),andtheElectronicIndustriesAssociation.v精读详解精读详解 Intensive reading： Ongoing DevelopmentsLesson 3 电电 信信 Telecommunications Oneofthegoalsoftheseorganiz

166、ationisthefullrealizationoftheintegratedservicesdigitalnetwork(ISDN),whichisprojectedtobecapableortransmittingthroughavarietyofmediaandatveryhighspeedsbothvoiceandnon-voicedataaroundtheworldindigitalform.v精读详解精读详解 Intensive reading： Ongoing DevelopmentsLesson 3 电电 信信 Telecommunications Other develop

167、mentsintheindustryareaimedatincreasingthespeedatwhichdatacanbetransmitted.Improvementsarebeingmadecontinuallyinmodemsandinthecommunicationsnetworks.Somepublicdatanetworkssupporttransmissionof56,000bitspersecond(bps),andmodemsforhomeusearecapableofasmuchas28,800bps.v精读详解精读详解 Intensive reading：Lesson

168、4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSP (UNIT 9 Passage A ) Lesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSPv内容大纲内容大纲 Outline：1. The essentials of analog-to-digital and digital-to-analog conversionA/D： anti-aliasing， sampling， quantization， digitizationD/A：smoothingconverting, zero order

169、 hold,Lesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSPv内容大纲内容大纲 Outline：2. Technologies for digital signal processing Digital signal processors are at the center of signal processing. some advantages of designing with DSPs over other microprocessors the other alternatives available for digital

170、signal processingFPGAASICGPPLesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSP see page 115vWords and expressions：Lesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSPAdigitalsignalisanumericalrepresentationoftheanalogsignal.Itmaybeeasierandmorecosteffectivetoprocessthesesignalsinthedigitalworld.

171、Intherealworld,wecanconvertthesesignalsintodigitalsignalsthroughtheanalog-to-digitalconverter,processthesignals,andifneeded,bringthesignalsbackouttotheanalogworldthroughthedigital-to-analogconverter.v精读详解精读详解 Intensive reading：Lesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSP1. The essentials of

172、 analog-to-digital and digital-to-analog conversionThefirstessentialstepinanalog-to-digital(A/D)conversion(asshowninFigure9.1)istosampleananalogsignal.Thisstepisperformedbyasampleandholdcircuit,whichsamplesatregularintervalscalledsamplingintervals.Thelengthofthesamplingintervalisthesameasthesampling

173、period,andthereciprocalofthesamplingperiodisthesamplingfrequencyfs.v精读详解精读详解 Intensive reading：Lesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSPWhenthisminimumisnotrespected,distortioncalledaliasingoccurs.Aliasingcauseshighfrequencysignalstoappearaslowerfrequencysignals.Tobesurealiasingwillnotoc

174、cur,samplingisalwaysprecededbylowpassfiltering.Thelowpassfilter,calledtheanti-aliasingfilter,removesallfrequenciesabovehalftheselectedsamplingrate.v精读详解精读详解 Intensive reading：Lesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSPv精读详解精读详解 Intensive reading：Afterabriefacquisitiontime,duringwhichasampl

175、eisacquired,thesampleandholdcircuitholdsthesamplesteadyfortheremainderofthesamplinginterval.ThisholdtimeisneededtoallowtimeforanA/Dconvertertogenerateadigitalcodethatbestcorrespondstotheanalogsample.Lesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSPv精读详解精读详解 Intensive reading：TheA/Dconverterchoos

176、esaquantizationlevelforeachanalogsample.AnN-bitconverterchoosesamong2N possiblequantizationlevels.Thelargerthenumberoflevels,thesmallerthequantizationerrors,calculatedasthedifferencebetweenthequantizedlevelandthetruesamplelevel.MostquantizationerrorsarelimitedinsizetohalfaquantizationstepQ.Thequanti

177、zationstepsizeiscalculatedasQ=R/2N,whereRisthefullscalerangeoftheanalogsignalandNisthenumberofbitsusedbytheconverter.Lesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSPv精读详解精读详解 Intensive reading：Finally,eachdigitalsampleisassignedadigitalcode,whichcompletestheA/Dprocess.Theresultisadigitalbitstre

178、am.Itisthiscollectionofdigitalcodesthatisprocessedindigitalsignalprocessing.Tosummarize,A/Dcomprisesanti-aliasing,sampling,quantizationanddigitization.Lesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSPv精读详解精读详解 Intensive reading：Oncedigitalsignalprocessingiscomplete,digital-to-analog(D/A)conversi

179、on(asshowninFigure9.2)mustoccur.Thisprocessbeginsbyconvertingeachdigitalcodeintoananalogvoltagethatisproportionalinsizetothenumberrepresentedbythecode.Thisvoltageisheldsteadythroughzeroorderholduntilthenextcodeisavailable,onesamplingintervallater.Thiscreatesastaircase-likesignalthatcontainsfrequenci

180、esaboveWHz.Thesesignalsareremovedwithasmoothinglowpassfilter,thelaststepinD/Aconversion.Lesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSPv精读详解精读详解 Intensive reading：Lesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSPv精读详解精读详解 Intensive reading：2. Technologies for digital signal processingAdigi

181、tal signal processor(DSP)isatypeofmicro-processoronethatisincrediblyfastandpowerful.ADSPisuniquebecauseitprocessesdatainrealtime.Thisreal-timecapabilitymakesaDSPperfectforapplicationsthatcannottolerateanydelays.Forexample,didyouevertalkonacellphonewheretwopeoplecouldnttalkatonce?Youhadtowaituntilthe

182、otherpersonfinishedtalking.Lesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSPv精读详解精读详解 Intensive reading：Ifyoubothspokesimultaneously,thesignalwascutyoudidntheartheotherperson.Withtodaysdigitalcellphones,whichuseDSP,youcantalknormally.Herearejustsomeofthe advantagesofdesigningwithDSPsoverothermic

183、roprocessors:Lesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSPv精读详解精读详解 Intensive reading：Single-cyclemultiply-accumulateoperations;Real-timeperformancesimulationandemulation;Flexibility;Reliability;Increasedsystemperformance;Reducedsystemcost.Lesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DS

184、Pv精读详解精读详解 Intensive reading：However,therearesomeofthe other alternativesavailablefordigitalsignalprocessing.HowtheycomparetoDSPs?TheFPGAAlternativeField-Programmable Gate Arrays (FPGA)havethecapabilityofbeingreconfigurablewithinasystem,whichcanbeabigadvantageinapplicationsthatneedmultipletrialversi

185、onswithindevelopment,offeringreasonablyfasttimetomarket.Lesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSPv精读详解精读详解 Intensive reading：Theyalsooffergreaterrawperformanceperspecificoperationbecauseoftheresultingdedicatedlogiccircuit.However,FPGAsaresignificantlymoreexpensiveandtypicallyhavemuchhigh

186、erpowerdissipationthanDSPswithsimilarfunctionality.Assuch,evenwhenFPGAsarethechosenperformancetechnologyindesignssuchaswirelessinfrastructure,DSPsaretypicallyusedinconjunctionwithFPGAstoprovidegreaterflexibility,betterprice/performanceratios,andlowersystempower.Lesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic

187、Concepts of DSPv精读详解精读详解 Intensive reading：TheASICAlternativeApplication-specific ICs (ASIC)canbetailoredtoperformspecificfunctionsextremelywell,andcanbemadequitepowerefficient.However,sinceASICSarenotfield-programmable,theirfunctionalitycannotbeiterativelychangedorupdatedwhileinproductdevelopment.A

188、ssuch,everynewversionoftheproductrequiresaredesignandtripsthroughthefoundry,anexpensiveproposition,andanimpediment torapidtime-to-market.ProgrammableDSPs,ontheotherhand,canbeupdatedwithoutchangingthesilicon,merelychangethesoftwareprogram,greatlyreducingdevelopmentcosts,andavailingaftermarketfeaturee

189、nhancementswithmerecodedownloads.Consequently,moreoftenthannot,whenyouseeASICsinrealtimesignalprocessingapplications,theyaretypicallyemployedasbusinterfaces,gluelogic,and/orfunctionalacceleratorsforaprogrammableDSP-basedsystem.Lesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSPv精读详解精读详解 Intensive

190、reading：TheGPPAlternativeIncontrasttoASICsthatareoptimizedforspecificfunctions,general-purpose microprocessors (GPPs)arebestsuitedforperformingabroadarrayoftasks.However,forapplicationsinwhichtheendproductmustprocessanswersinrealtime,ormustdosowhilepoweredbyconsumerbatteries,GPPscom-parativelypoorre

191、altimeperformanceandhighpowerconsump-tionallbutrulesthemout.Moreandmore,theseprocessorsarebeingseenasthedinosaursoftheindustry,tooencumberedwithPCcompatibilityanddesktopfeaturestoadapttothechangingrealtimemarketplace.Astheworldembracestinyhand-heldwireless-enabledproductsthatrequirepowerdissipationm

192、easuredinmilliwattsnotthewattsthattheseprocessorsconsumeDSPsaretheprogrammabletechnologyofchoice.ThattrendisboundtocontinueasdigitalInternetappliancesgetsmaller,fasterandmoreportable.Lesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSPsatellite-basedcommunicationX-based基于X的e.g.UNIX-basedoperatingsy

193、stemv补充材料补充材料Supplementary materials:AbebasedonB.e.g.Thetheoryisbasedonaseriesofwrongassumptions.e.g.Thecommunicationisbasedonsatellite.e.g.Basedontheseprinciples,Lesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSPv补充材料补充材料Supplementary materials:X-oriented面向X的e.g.object-orientedprogramming,proces

194、s-orientedprogramming,OOAD:object-orientedanalysisanddesignX-free无X的,免除X的e.g.nuclear-weapon-freezone,radio-free,interference-freefree-X自由的,免费的,易的e.g.free-oscillation,free-phone,free-fall,free-cuttingLesson 4 数字信号处理的基本概念数字信号处理的基本概念 Basic Concepts of DSPv补充材料补充材料Supplementary materials:X-independent与X

195、无关的e.g.position-independentcode,distance-independentcostindependent-独立的independentvariablesLesson 5 电路交换和分组交换电路交换和分组交换 Circuit Switching and Packet Switching (UNIT 21 Passage B) Lesson 5 电路交换和分组交换电路交换和分组交换 Circuit Switching and Packet Switching vWords and expressions：circuitswitching电路交换messageswitc

196、hing报文交换packetswitching分组交换Lesson 5 电路交换和分组交换电路交换和分组交换 Circuit Switching and Packet Switching vWords and expressions： see page 262v内容大纲内容大纲 Outline：Paragraph 1: Lesson 5 电路交换和分组交换电路交换和分组交换 Circuit Switching and Packet Switching Paragraph 2: Paragraph 3: Paragraph 4: Paragraph 5: circuit switching me

197、ssage switchingpacket switching( a variation of message switching ) feature analysis between circuit switching and message switchingadded features and problems in packet switchingTherearetwobasictypesofswitchingtechniques:circuitswitchingandmessageswitching.In circuit switching,atotalpathofconnected

198、linessetupfromtheorigintothedestinationatthetimethecallismade,andthepathremainsallocatedtothesource-destinationpair(whetherusedornot)untilitreleasedbythecommunicatingparties.Theswitches,calledcircuitswitches(orofficeexchangeintelephonejargon),havenocapabilityofstoringormanipulatingusersdataontheirwa

199、ytothedestination.Lesson 5 电路交换和分组交换电路交换和分组交换 Circuit Switching and Packet Switching v精读详解精读详解 Intensive reading：Paragraph 1: Thecircuitissetupbyaspecialsignalingmessagethatfindsitswaythroughthenetwork,seizingchannelsinthepathasitproceeds.Oncethepathisestablished,arereturnsignalinformsthesourcetobeg

200、intransmissionDirecttransmissionofdatafromsourcetodestinationcanthentakeplacewithoutanyinterventiononthepartofthesubnet.Lesson 5 电路交换和分组交换电路交换和分组交换 Circuit Switching and Packet Switching v精读详解精读详解 Intensive reading：Inmessage switching,thetransmissionunitisawell-definedblockofdatacalledamessageInaddi

201、tiontothetexttobetransmitted,amessagecomprisesaheaderandachecksumThe headercontainsinformationregardingthesourceanddestinationaddressesaswellasothercontrolinformation;the checksumisusedforerrorcontrolpurposes.Lesson 5 电路交换和分组交换电路交换和分组交换 Circuit Switching and Packet Switching v精读详解精读详解 Intensive read

202、ing：Paragraph 2: Theswitchingelementisacomputerreferredtoasamessageprocessor,withprocessingandstoragecapabilities.Messagestravelindependentlyandasynchronously,timingtheirownwayfromsourcetodestination.Firstthemessageistransmittedfromthehosttothemessageprocessortowhichitisattached.Oncethemessageisenti

203、relyreceived,themessageprocessorexaminesitsheader,andaccordinglydecidesonthenextoutgoingchannelonwhichtotransmitit.Lesson 5 电路交换和分组交换电路交换和分组交换 Circuit Switching and Packet Switching v精读详解精读详解 Intensive reading：Ifthisselectedchannelisbusy,themessagewaitsinaqueueuntilthechannelbecomesfree,atwhichtimet

204、ransmissionbegins.Atthenextmessageprocessor,themessageisagainreceived,stored,examined,andtransmittedonsomeoutgoingchannel,andthesameprocesscontinuesuntilthemessageisdeliveredtoitsdestination.Thistransmissiontechniqueisalsoreferredtoasthestore-and-forwardtransmissiontechnique.Lesson 5 电路交换和分组交换电路交换和分

205、组交换 Circuit Switching and Packet Switching v精读详解精读详解 Intensive reading：Avariationofmessageswitchingispacket switching.Herethemessageisbrokenupintoseveralpiecesofagivenmaximumlength,calledpackets.Aswithmessageswitching,eachpacketcontainsaheaderandachecksum.Packetsaretransmittedindependentlyinastore-a

206、nd-forwardmanner.Lesson 5 电路交换和分组交换电路交换和分组交换 Circuit Switching and Packet Switching v精读详解精读详解 Intensive reading：Paragraph 3: Withcircuitswitching,thereisalwaysaninitialconnectioncostincurredinsettingupthecircuit.Itiscost-effectiveonlyinthosesituationswhereoncethecircuitissetupthereisaguaranteedstead

207、yflowofinformationtransfertoamortizetheinitialcost.Thisiscertainlythecasewithvoicecommunicationinthetraditionalway,andindeedcircuitswitchingisthetechniqueusedinthetelephonesystem.Lesson 5 电路交换和分组交换电路交换和分组交换 Circuit Switching and Packet Switching v精读详解精读详解 Intensive reading：Paragraph 4: Communication

208、amongcomputers,however,ischaracterizedasbursty.Burstinessisaresultofthehighdegreeofrandomnessencounteredinthemessage-generationprocessandthemessagesize,andofthelowdelayconstraintrequiredbytheuser.Theusersanddevicesrequirethecommunicationresourcesrelativelyinfrequently;butwhentheydo,theyrequirearelat

209、ivelyrapidresponse.Lesson 5 电路交换和分组交换电路交换和分组交换 Circuit Switching and Packet Switching v精读详解精读详解 Intensive reading： Ifafixeddedicatedend-to-endcircuitweretobesetupconnectingtheendusers,thenonemustassignenoughtransmissionbandwidthtothecircuitinordertomeetthedelayconstraintwiththeconsequencethattheresu

210、ltingchannelutilizationislow.If thecircuitofhighbandwidthweresetupandreleasedateachmessagetransmissionrequest,thentheset-uptimewouldbelargecomparedtothetransmissiontimeofthemessage,resultingagaininlow channel utilization.Lesson 5 电路交换和分组交换电路交换和分组交换 Circuit Switching and Packet Switching v精读详解精读详解 In

211、tensive reading：Therefore,forburstyusers(whichcanalsobecharacterizedbyhighpeak-to-average data raterequirements),store-and-forwardtransmissiontechniquesofferamorecost-effectivesolution,sinceamessageoccupiesaparticularcommunicationslinkonlyforthedurationofitstransmissiononthatlink;therestofthetimeiti

212、sstoredatsomeintermediatemessageswitchandthelinkisavailableforothertransmissions.Lesson 5 电路交换和分组交换电路交换和分组交换 Circuit Switching and Packet Switching v精读详解精读详解 Intensive reading：Thusthemain advantageofstore-and-forwardtransmissionovercircuitswitchingisthatthecommunicationbandwidthisdynamicallyallocate

213、d,andtheallocationisdoneonthefinebasisofaparticularlinkinthenetworkandaparticularmessage(foraparticularsource-destinationpair).Lesson 5 电路交换和分组交换电路交换和分组交换 Circuit Switching and Packet Switching v精读详解精读详解 Intensive reading：Packet switching achieves the benefitsdiscussedsofarandoffers added features.I

214、tprovidesthefulladvantageofthedynamicallocationofthebandwidth,evenwhenmessagesarelong.Indeed,withpacketswitching,manypacketsofthesamemessagemaybeintransmissionsimultaneouslyoverconsecutivelinksofapathfromsourcetodestination,thusachievinga“pipelining”effectandreducingconsiderablytheoveralltransmissio

215、ndelayofthemessageascomparedtomessageswitching.Lesson 5 电路交换和分组交换电路交换和分组交换 Circuit Switching and Packet Switching v精读详解精读详解 Intensive reading：Paragraph 5: Ittendstorequiresmallerstorageallocationattheintermediateswitches.Italsohasbettererrorcharacteristicsandleadstomoreefficienterrorrecoveryprocedur

216、es,asitdealswithsmallerentities.Needlesstosay,packetswitchingpresentsdesignproblemsofitsown,suchastheneedtoreorderpacketsofagivenmessagethatmayarriveatthedestinationnodeoutofsequence.Lesson 5 电路交换和分组交换电路交换和分组交换 Circuit Switching and Packet Switching v精读详解精读详解 Intensive reading：Lesson 6 计算机网络计算机网络 Co

217、mputer Networks (UNIT 23 Passage A) Lesson 6 计算机网络计算机网络 Computer NetworksvWords and expressions： see page 287Lesson 6 计算机网络计算机网络 Computer Networksv精读详解精读详解 Intensive reading：Networkscanbeanalog,inwhichinformationisrepresentedbycontinuoussmoothlyvaryingsignals,ordigital,inwhichinformationisrepresente

218、dbydiscreteon/offsignals.Digitalsignalsareanewertechnologyfoundincomputersystems,localareanetworks,compactdisks,andhighdefinitiontelevision(HDTV).Digitalsignalsarediscreteon/offsignalsthatcanbeeasilystored,compressed,edited,andmanipulated.Lesson 6 计算机网络计算机网络 Computer Networksv精读详解精读详解 Intensive read

219、ing：Thetelephoneindustryisintheprocessofconvertingtoanall-digitalnetworkcalledIntegratedServicesDigitalNetwork(ISDN)andsimilarupgradesareproposedforcellulartelephonenetworks.Therearethree major categories of networksdistinguishedprimarilybygeography:wideareanetworks,metropolitanareanetworks,andlocal

220、-areanetworks.Lesson 6 计算机网络计算机网络 Computer Networksv精读详解精读详解 Intensive reading：1. Wide area NetworksWideareanetworks(WANs)providecommunicationsacrossacountryortheentireworld.Thetelephonenetworkisthemostpervasiveexample.Itisoftenviewedasasingleentity,eventhoughitismadeupofavarietyofseparatecompanies.

221、2. Metropolitan area NetworksMetropolitanareaNetworks(MANs)providecommunicationsacrossandamongmajormetropolitanareassuchasNewYork,Chicago,orLosAngeles.Lesson 6 计算机网络计算机网络 Computer Networksv精读详解精读详解 Intensive reading：Amorerecentdevelopmentisthepublicvoiceanddatanetworks.Anexampleyoumaybefamiliarwithi

222、sthe cellular telephone network,whichismadepossiblebydividingageographicalareaintohexagonal-shapedcells,eachwithabasestation.Eachcell,whichisapproximately10miles(16kilometers)across,hasitsownantenna.Likethepublictelephonenetwork,publicMANseliminatetheneedforindividualsandorganizationstobuildandopera

223、tetheirownnetworks.hexagon六边形hexagonaladj -gon边形:trigon,tetragon,pentagon,heptagon,octagon,nonagon/enneagon,decagon-hedron面体：tetrahedron,pentahedron,octahedron-angle角形、边形：triangle,quadrangle,septanglerectangle，rectangled直角的inch(inches)英寸foot(feet)英尺mile(miles)英里1inch=25.4millimetres1foot=12inches=0.

224、3048metre1yard=3feet=0.9144metre1mile=1760yards=1.609kilometres1nauticalmile=1.852kilometrescell电池，蜂窝，小区(移动技术)，信元(ATM技术)cellularadjmacrocell宏小区,宏蜂窝microcell微小区,微蜂窝Lesson 6 计算机网络计算机网络 Computer Networksv精读详解精读详解 Intensive reading：3. Local area NetworksLocalareaNetworks(LANs)providecommunicationswithin

225、specificbuildingsorfacilities.Thistypeofnetworkcouldbeused,forexample,inacompanywherecomputersarelocatedinthesales,accounting,production,andpurchasingdepartments.Local-areanetworkshavemanydifferent topologies,orwaysinwhichcomputercanbeconnectedtothenetwork.Today,thetwomostcommontopologiesarecalledri

226、ngandbusnetworks.Topologies the point to pointLesson 6 计算机网络计算机网络 Computer Networksv补充材料补充材料Supplementary materials:Topologies the starLesson 6 计算机网络计算机网络 Computer Networksv补充材料补充材料Supplementary materials:Topologies the bus the treeLesson 6 计算机网络计算机网络 Computer Networksv补充材料补充材料Supplementary material

227、s:Topologies the ring the meshLesson 6 计算机网络计算机网络 Computer Networksv补充材料补充材料Supplementary materials:Lesson 6 计算机网络计算机网络 Computer Networksv精读详解精读详解 Intensive reading：The three major categories of networks are not mutually exclusive.Amobileworkerusingaportablecomputercansendamessagetoacoworkerinacross

228、thecountryofficebecausethenetworkscanbelinkedthroughgateways-devicesusedtoconnectdissimilarnetworks.Forexample,themobileworkersmessagemightfirstbetransmittedtoalocalcellularbasestation,switchedtothetelephonenetworkandcarriedacrossthecountrytothecoworkersoffice,thentransferredviagatewayintotheofficeL

229、AN.Lesson 7 TD-SCDMA 一种3G无线接入技术 TD-SCDMA a 3G Radio Access Technology (UNIT 16 Passage A) Intensive reading：1.Lesson 7 TD-SCDMA a 3G Radio Access Technology v技术背景技术背景 Background：1G(analogcellulartelephonesystem)AMPS:AdvancedMobileTelephoneSystem高级移动电话系统（美）2G(digitalcellulartelephonesystem(DCS)GSM:Gl

230、obalSystemforMobileCommunication全球移动通信系统2.5GGPRS:GeneralPacketRadioService通用无线分组协议3GCDMA:CodeDivisionMultipleAccessing码分多址技术Lesson 7 TD-SCDMA a 3G Radio Access Technology v技术背景技术背景 Background：TD-SCDMA:TimeDivision-SynchronousCDMAWCDMA:WidebandCDMAChina Telecom3G: CDMACDMA2000China UnicomChina Mobile

231、Lesson 7 TD-SCDMA a 3G Radio Access Technology v技术背景技术背景 Background：FDMA:FrequencyDivisionMultipleAccessingTDMA:TimeDivisionMultipleAccessingCDMA:CodeDivisionMultipleAccessingFDM:FrequencyDivisionMultiplexingTDM:TimeDivisionMultiplexingCDM:CodeDivisionMultiplexing多址多址复用复用The sharing of channelsLesso

232、n 7 TD-SCDMA a 3G Radio Access Technology v技术背景技术背景 Background：FDMA频率频率Lesson 7 TD-SCDMA a 3G Radio Access Technology v技术背景技术背景 Background：TDMALesson 7 TD-SCDMA a 3G Radio Access Technology v技术背景技术背景 Background：FH-CDMAfrequency hopped DS-CDMAdirect sequencespread-spectrum 扩频PN: pseudo-random伪随机CDMAL

233、esson 7 TD-SCDMA a 3G Radio Access Technology v技术背景技术背景 Background：Basetransceiverstation(BTS)MSC:MobileswitchingcenterMobileunitDedicatedlines A typical cellular system topologyTransmission Modes simplex (SX) 单工单工 half duplex /semi-duplex (HDX) 半双工半双工 full duplex (FDX) 全双工全双工 full / full duplex (F/

234、FDX) 全全/全双工全双工 multiplex (MX) 多工多工v补充材料补充材料Supplementary materials:Lesson 7 TD-SCDMA a 3G Radio Access Technology Lesson 7 TD-SCDMA a 3G Radio Access Technology vWords and expressions： see page 193-195Lesson 7 TD-SCDMA a 3G Radio Access Technology v精读详解精读详解 Intensive reading：1. What is TD-SCDMA?Join

235、tlydevelopedbySiemensandtheChinaAcademyofTelecommunicationsTechnology(CATT),TD-SCDMA(TimeDivisionSynchronousCodeDivisionMultipleAccess)isoneofthefiveIMT-2000standardsacceptedbytheITU.InMarch2001thestandardwasalsoadoptedbytheThirdGenerationPartneringProject(3GPP),aspartofUMTSRelease4.Inthiswayitbecam

236、eatrulyglobalstandard,whichcoversallradiodeploymentscenarios:fromruraltodenseurbanareas,frompedestriantohighmobility.Lesson 7 TD-SCDMA a 3G Radio Access Technology v精读详解精读详解 Intensive reading：DesignedasanadvancedTDMA/TDDsystemwithanadaptiveCDMAcomponentoperatinginsynchronousmode,TD-SCDMAmastersboths

237、ymmetriccircuitswitchedservices(suchasspeechorvideo)aswellasasymmetricpacketswitchedservices(suchasmobileInternetaccess).Lesson 7 TD-SCDMA a 3G Radio Access Technology v精读详解精读详解 Intensive reading：Themainbenefits ofTD-SCDMAarethatitcanbeimplementedlessexpensivelythancomparable3Gsystemssinceitismuchmo

238、respectrumefficientandiscompatiblewithGSMnetworkelements,allowing3Gserviceswithoutinstallationofcompletelynewinfrastructure.The key benefits are: Lesson 7 TD-SCDMA a 3G Radio Access Technology v精读详解精读详解 Intensive reading：Services optimally suited for asymmetric 3G applications (mobile Internet).Real

239、-time applicationslikevoiceandmultimediarequireminimumdelayduringtransmissionandgeneratesymmetrictraffic.Fornon real-time applicationslikee-mailorInternetaccess,timingconstraintsarelessstrictandthegeneratedtrafficisasymmetric.Lesson 7 TD-SCDMA a 3G Radio Access Technology v精读详解精读详解 Intensive reading

240、：Forallthoseradiotechnologieswhichrequireseparatebandsforuplinkanddownlink(suchasGSM,EDGE,W-CDMAorCDMA2000)，portionsofthespectrumareoccupiedbutnotusedwhenanasymmetricdataloadisapplied.Theseidleresourcescannotbeutilizedforanyotherservice,leadingtoaninefficientuseofthespectrum.Lesson 7 TD-SCDMA a 3G R

241、adio Access Technology v精读详解精读详解 Intensive reading：On the contrary,TD-SCDMAadaptstheuplink/downlinkratioaccordingtothedataloadwithinasingleunpairedfrequencythusutilizingthespectrummoreefficiently,andprovidesdataratesrangingfrom1.2kbpsto2Mbps.Thisisespeciallyhelpfulinanenvironmentwithincreasingdatatr

242、affic(mobiledata),whichtendstobeasymmetric,oftenrequiringlittleuplinkthroughput,butsignificantbandwidthfordownloadinginformation(mobileInternet).Lesson 7 TD-SCDMA a 3G Radio Access Technology v精读详解精读详解 Intensive reading：Outstanding Spectrum Efficiency increases capacity.Asalreadystated,withasymmetri

243、ctrafficapplications,TD-SCDMAutilizestheavailablespectrummoreefficientlythanother3Gstandardssinceitemploysonlyonebandforbothuplinkanddownlinktraffic(TDDunpairedband)insteadoftwoseparatebandsforuplinkanddownlink(FDDpairedbands).Lesson 7 TD-SCDMA a 3G Radio Access Technology v精读详解精读详解 Intensive readin

244、g：Smooth migration to 3G.TD-SCDMAallowsaneasymigrationpath:GSM/GPRS/TD-SCDMA.3GservicesareintroducedaddingTD-SCDMAradiosubsystems to existingstableandestablishedGSMinfrastructures.Thetotalmigrationcostsfrom2Gto3Gdecreaseconsiderably,comparedtoother3Gstandards.Thetotalinvestmentriskisreducedandatthes

245、ametimeinvestmentinalreadypurchasedGSMinfrastructureissecured.Lesson 7 TD-SCDMA a 3G Radio Access Technology v精读详解精读详解 Intensive reading：Increased flexibility.TD-SCDMAscarrierbandwidthof1.6MHzprovideshighflexibilityinspectrumusageandnetworkdesign.Lesson 7 TD-SCDMA a 3G Radio Access Technology v精读详解精

246、读详解 Intensive reading：Low power emission.Beam Steering Smart Antennasdirectpowertoactivemobileterminalsonly.Thehighdirectivityandsensibilityofsmartantennatogetherwiththefactthatterminalstransmitpoweronlyduringactivetimeslotscontributestokeeptheterminalspowerconsumptionlow,whichleadstomorecosteffecti

247、vehandsets.Inaddition,sincethetransmittedpowerisdirectedonlytoactiveusers,theradioilluminatedareaisstronglyreduced.Lesson 7 TD-SCDMA a 3G Radio Access Technology v精读详解精读详解 Intensive reading：Reduced Investment Costs. Costs of Leased Lines reduced.Thanks tojointdetection,smartantennasandanaccurateterm

248、inalsynchronization,TD-SCDMAdoesnotneedtorelyonsofthandover.Onthecontrary,TD-SCDMAusesconventionalhandover(similarlytoGSM)whichleadstoasensiblereductionofthecostofleasedlinescomparedwithother3Gstandards. Simple Network planning.NetworkPlanningissensiblysimplifiedsinceTD-SCDMAisnotaffectedbycellbreat

249、hingandsofthandovers.Lesson 8 压缩压缩/解压缩技术解压缩技术 Compression / Decompression Techniques (UNIT 17 Passage B) Extensive readingv内容大纲内容大纲 Outline：Paragraph 1: Paragraph 2: Paragraph 3: Paragraph 4: a foreword to image compression only consider two general types of compression: (1) loss-less, and (2)lossLe

250、sson 8 压缩压缩/解压缩技术解压缩技术 Compression / Decompression Techniques loss-less technique v内容大纲内容大纲 Outline：Paragraph 5: Paragraph 6: Paragraph 7: Paragraph 8: principal components transform coding Vector QuantificationLesson 8 压缩压缩/解压缩技术解压缩技术 Compression / Decompression Techniques fractal compression Lesso

251、n 8 压缩压缩/解压缩技术解压缩技术 Compression / Decompression Techniques v Paragraph 1: Numerousmethodshavebeendevelopedforthecompressionofdigitalimagedata.Oneoftheprincipaldrivers forthisdevelopmentisthetelevisionindustrywherequalityimagedatamustbetransferredtoreceiversusingrelativelysimpleequipment.Thedevelopme

252、ntofhighdefinitiontelevisionisfurther focusingtheattentionofindustryanduniversityscientiststowardproblemsofdatareductionanddigitaltransmission. Lesson 8 压缩压缩/解压缩技术解压缩技术 Compression / Decompression Techniques v Paragraph 1: Theprincipalevaluation criteriafortheanalysisofcompressedversusuncompressedim

253、ageryiswhetherapersoncantellthedifferencebetweentheimages.Amoreimplemental measureistheRootMeanSquare(RMS)errorbetweentheoriginalimageandtheimagethathasbeencompressed.Compression ratesmaybegeneratedbydeterminingthesizeofthecompressedimageintermsofnumberofbitsperimagepixelfortheoriginalimage.Lesson 8

254、 压缩压缩/解压缩技术解压缩技术 Compression / Decompression Techniques v Paragraph 2: Hereweonlyconsidercompressionofsinglehighresolutionmulti-spectralimages.Higher compression rateswillbeachievedinamotionsequencewhereframetoframevariationsmaybequantifiedandonlythechangesfromareferenceimageneedbecoded.Lesson 8 压缩压

255、缩/解压缩技术解压缩技术 Compression / Decompression Techniques v Paragraph 3: Therearetwo general types of compression: (1) loss-less,and (2)loss.Loss-lesscompressionmeansthatyoucanachieveacertaincompressionfactorandbeabletoexactlyreproducetheoriginalimage.Loss compressionontheotherhandallowssomeloss,buthasthe

256、potentialformuchhighercompressionrates.Nomatterwhattechniquethatyouuse,theexactrateisverydependentonthecomplexityoftheimagethatyouareanalyzing.Forexample,.Lesson 8 压缩压缩/解压缩技术解压缩技术 Compression / Decompression Techniques v Paragraph 4: Oneloss-lesstechniqueisknownasrun length encoding.Thecompressional

257、gorithmprocesseseachlineofinputimagerylookingforregionsinwhichdatavaluesarethesame.Iftenpixelsintheoriginalimagehaveavalueof10,thenthesamedatamayberepresentedasadatavalue,10,andamultipliersayinghowmanytimesthevalueisrepeatedbeforeachangedvalue.Huffman encodingfollowsasimilarprocess.Lesson 8 压缩压缩/解压缩

258、技术解压缩技术 Compression / Decompression Techniques v Paragraph 4: Theseloss-lesstechniquesaregenerallycalledentropy codingtechniques,andhaveapplicationindocumentimaging,desktoppublishing,andGIS.It should be noted thatentropycodingdoesnotworkexceptionallywellintherepresentationofremote sensing images.Not

259、ethatLesson 8 压缩压缩/解压缩技术解压缩技术 Compression / Decompression Techniques v Paragraph 5: Inremotesensingimageryitiswellknownthattheremaybesignificantcorrelationbetweendifferentbandsofmulti-spectraldata.Inimageprocessing,aprocedurecalledprincipal componentshasbeendesignedtoidentifycorrelationbetweenimageb

260、andsandtocreateanewsetoftransformedbandsthatrepresentanewcolorspaceinwhichthenewimagebandsareuncorrelated.Lesson 8 压缩压缩/解压缩技术解压缩技术 Compression / Decompression Techniques v Paragraph 6: Anothertypeoftransform codingdoesnotinvolvearotationofthecolorspace,butinsteadrepresentsimagesintermsofspatialfrequ

261、encyofcertainbasefunctions.Fouriertransformsmapanimageintoaspatialfrequencyimagebasedonsineandcosinefunctions.AfastcomputerimplementationoftheDiscreteFourierTransform(DFT)isknownasaFast Fourier Transform (FFT).Discrete Cosine Transforms(DCTs)mapthesameimagetoaspatialfrequencyimagebasedonlyonthecosin

262、efunction.Lesson 8 压缩压缩/解压缩技术解压缩技术 Compression / Decompression Techniques v Paragraph 7: Vector Quantification (VQ)isatypeofencodingthatdefinesavectorrepresentationofnon-overlappingareablockswithinanimage.Avectorconsistsofvaluesrepresentingthedatavaluesforeachpixelwithintheregion.Usingthesevectors,c

263、lustersofvectorsarederivedusingaderivedspectraldistancemeasure.Lesson 8 压缩压缩/解压缩技术解压缩技术 Compression / Decompression Techniques v Paragraph 8: Thelasttypeofcompressionconsideredisfractal compression.Fractalcompressioncanachievecompressionratiosofupto80toonewithonlymoderatelossofinformation.Thefractal

264、technique,liketheVQtechniqueisalsoasymmetric.Hardwareimplementationofthedecompressionoffractalimageshasachievedreal-timerates.withlesslosswithlittlelosspixel 像素histogram 直方图perimeter 周长rows and columns 行和列gray scale image 灰度图像gray scale level 灰度级contrast 对比度edge detection 边缘检测object recognition 目标识别

265、 Lesson 8 压缩压缩/解压缩技术解压缩技术 Compression / Decompression Techniques v补充材料补充材料Supplementary materials:coordinate 坐标 Lesson 8 压缩压缩/解压缩技术解压缩技术 Compression / Decompression Techniques v补充材料补充材料Supplementary materials:rectangular 直角坐标polar 极坐标ordinate 纵坐标，纵轴abscissa 横坐标，横轴origin 原点Lesson 9 产品手册阅读产品手册阅读 Data

266、Sheet Reading Data Sheet Reading 产品手册阅读产品手册阅读vThe Information we can acquire from data sheets:the model 型号型号manufacturer 厂商厂商the feature 产品特性产品特性the name 名称名称the description 产品描述产品描述the specifications 指标指标absolute maximum ratings 最大绝对额定值最大绝对额定值the block diagram 产品内部结构框图产品内部结构框图typical characteristic

267、s 典型特性（电气特性）典型特性（电气特性）vThe Information we can acquire from data sheets:applications 产品应用产品应用outline dimensions 外观规格（外观规格（package 封装）封装）ordering information 定购信息定购信息 Data Sheet Reading 产品手册阅读产品手册阅读vWordsAD620 Data Sheet Reading 产品手册阅读产品手册阅读integratedoperationalamplifier集成运算放大器instrumentationamplifier

268、仪器放大器inputstage输入级midgainstage中间增益级outputstage输出级common-mode共模difference-mode差模CMRR：Common-moderejectionratio共模抑制比gain增益vWordsAD620 Data Sheet Reading 产品手册阅读产品手册阅读biasingcircuit偏置电路offsetvoltage失调电压driftcurrent漂移电流diffusioncurrent扩散电流temperaturedrift温漂Volt-Amperecharacteristic伏安特性reversesaturationcu

269、rrent反向饱和电流breakdown击穿vWordsAD620 Data Sheet Reading 产品手册阅读产品手册阅读diode二极管LED:Light-EmittingDiode发光二极管seven-segmentLEDdisplay七段LED显示器photodiode光敏二极管triode三极(真空)管transistor晶体管，晶体三极管FET:fieldeffecttransistor场效应晶体管MOS:metal-oxidesemiconductor金属-氧化物-半导体CMOS:complementary互补金属-氧化物-半导体TTL:Transistor-Transis

270、torLogic三极管-三极管逻辑/晶体管-晶体管逻辑vWordsAD620 Data Sheet Reading 产品手册阅读产品手册阅读gate栅极source源极drain漏极substrate衬底极emitter发射极base基极collector集电极commonbase共基极amplifiermode放大模式saturationmode饱和模式cut-offmode截止模式cut-off截止turn-on导通vWordsAD620 Data Sheet Reading 产品手册阅读产品手册阅读rectifier整流器rectify整流regulator稳压器voltageregul

271、ation稳压transformer变压器，变量器converter变频器，变流器，变换器，转换器reset-setflip-flop/triggerRS触发器monostabletriggercircuit单稳态触发电路bistabletriggercircuit双稳态触发电路vWordsAD620 Data Sheet Reading 产品手册阅读产品手册阅读transconductance跨导，互导transresistance互阻lower/upperthreshold下/上门限(阈值)vWordsAT91RM9200 Data Sheet Reading 产品手册阅读产品手册阅读AR

272、M920T-basedMicrocontroller：AT91RM9200基于ARM920T的微控制器：AT91RM9200microcontrollermicroprocessor200MIPSat180MHzMIPS:MillionInstructionsPerSecondmemory存储器、内存RAM,ROMcache高速缓存datacache,instructioncachebuffer缓冲器、缓冲区writebuffervWordsAT91RM9200 Data Sheet Reading 产品手册阅读产品手册阅读emulator仿真器emulate，emulation仿真simul

273、ator模拟仿真器simulate，simulationdebug调试、除错（de-bug）embedded嵌入的，嵌入式的，内嵌的embeddedsystem嵌入式系统built-in：built-instorageapplicationperipheralsandstandardinterfaces应用外围设备和标准接口standbymode待机模式（一种省电工作模式）vWordsAT91RM9200 Data Sheet Reading 产品手册阅读产品手册阅读ROM:ReadOnlyMemoryPROM:ProgrammableEPROM:ErasableEEPROM:Electric

274、allyFLASHRAM:RandomAccessMemorySRAM:StaticRAMDRAM:DynamicRAMSDRAM:SynchronousDRAMDDRSDRAM(DDRAM):DoubleDataRateSDRAMvWordsAT91RM9200 Data Sheet Reading 产品手册阅读产品手册阅读EBI:ExternalBusInterfaceSPI:SerialPeripheralInterfaceI2C:InterIntegratedCircuitbusMCI:MultimediaCardInterfacemultimediacard:CF、MS、SD、MMC

275、USART:UniversalSynchronous/AsynchronousReceiver/TransmittersSatellitepassiveactive被动的、消极的主动的、积极的无源的有源的e.g.passivesatelliteactivesatellitepassiveantenna activeantennapassiverepeater activerepeaterpassiveelementactiveelementvWordsspacecraft航天器，宇宙飞行器，宇宙飞船aircraft航空器，飞行器，飞机craft工艺，手艺，船，飞机vWordsvWordsAft

276、erthesatellitewasplacedinalowearthorbit,signalsrelayedtoEchoreflectedorbouncedoffitssurfaceandreturnedtodifferentlocationsontheearth.orbit:inalowearthorbit低地轨道,近地轨道inageostationaryorbit对地静止轨道,同步轨道geostationary:geo-stationarystationary,fixedmobile静止的,固定的移动的staticdynamic静态的动态的vWordsItrelayeditsownsign

277、altoearthrelay:中继,转发repeater,transponder中继器,转发器regenerativerepeater,satelliterepeater/transponderbelowthehorizon,abovethehorizon/onthehorizon 部分词汇归纳（中文词意仅供参考）部分词汇归纳（中文词意仅供参考）以以-ble结尾的形容词通常有结尾的形容词通常有-bility形式的名词形式的名词 availability可用性 有效性 利用度adaptability 可用性 适应性adoptability 采纳性 可接受性applicability 适用性 适应

278、性flexibility 灵活性 适应性 柔性mobility 灵活性 机动性reliability 可靠性Appendixmaintainability 可维护性performability 可执行性 （performance 性能 特性 完成 实现）feasibility 可行性 可能性operability可操作性 操作性能interoperability互操作性 互通性capability 能力 性能 容量 (capacity 电容 容量 能力capacitance 电容 容量) compatibility 兼容性 相容性responsibility 响应度 责任accessibili

279、ty 接通度 访问能力removability 可移动性 可拆卸性durability 耐用性 耐久力stability 稳定性probability 概率possibility 可能性transportability 可运输性，可移植性portability 可移植性 轻便reachability 可达性susceptibility 磁化率 敏感度 灵敏度 （susceptance 电纳）survivability 残存性 生存性 抗毁性reproducibility 再现性intelligibility 可懂性 readability 可读性 明确性visibility 可见度 能见度 视

280、见度audibility 可听度 可闻度permeability 磁导率 渗透性 （permeance 磁导 渗透）indefinability不确定性（definability的反意）以以-ive结尾的形容词通常有结尾的形容词通常有-tivity形式的名词形式的名词connectivity 连通性conductivity 传导率 （conductance 电导 传导）inductivity 感应率 （inductance 电感）resistivity 电阻率 （resistance 电阻）refractivity 折射率reflectivity 反射率relativity 相对性 相对论 相

281、关性 (relevance 相关性 关联性)permittivity 电容率 介电常数(=electric constant)sensitivity 灵敏度creativity 创造力productivity 生产力 生产率selectivity 选择性alternativitycomplexity复杂度、复杂性simplification 简易性、简化itude名词名词 altitude 高度amplitude 振幅 幅度attitude 姿态 态度longitude 经度latitude 纬度multitude 大量 众多magnitude 数量 量级 重要性（非专业词汇：）（非专业词汇：

282、）aptitude 倾向 才能 （apt）similitude 类似 比喻 （similar）solicitude 挂念 关心 (solicitous)gratitude 感恩 （grateful）atom proton electron ion neutron原子原子 质子质子 电子电子 离子离子 中子中子 molecule photon 分子分子 光子光子EXAMI Explain the following abbreviations.(choose10fromthefollowings)II Translate the following passages into Chinese. 45 Passages III Read the following passages and answer the questions as required.2 Passages IV Translate the following Abstract into English. (ChoiceofTwoAbstracts)