综合专业英语试题

专业英语试题一、词语翻译

1.Electromagnetic induction 电磁感应

2.Broadcasting 广播

3.发射机Transmitter

4.Encoder 编码器

5.光电阴极Photocathode

6.像素Pixel

7.Harmonic structure 谐波结构

8.多路器Mutiplexer

9.电离层Ionosphere

10.Deterministic 确定的

11.功率谱密度power clensity spectrum

12.信噪比signal-to-noise ratio

13.Demodulation 解调，检波14.Nonlinear 非线性的

15.V acuum-tube 真空（电子）管

16.Modulation coefficient 调制系数

17.Upper side frequency 上边频

18.调制信号modulation signal

19.直流电源DC power suply

20.Quadrature 正交

21.振荡器resonator

22.Inversion 倒置

23.差分difference

24.Cascade 串联，级联

25.Deemphasis 去加重

1.field-effect 场效应管

2.oscilloscope 示波器

https://www.360docs.net/doc/3c6846468.html,rmation 信息，消息，情报

4.optical fiber 光纤

5. signal-to-noise 信噪比

6.bandwidth 基带

7.vocal tract 声带

8.bipolar 双极（线）的

9.decoder 解（译）码器

10.Fourier series 傅里叶级数

11.decibel 分贝

12.modulation 调制，调节

13.amplifier 放大器，扩音机

14. transformer 变压器

15.resonator 振荡器

16.prescribe 指示，规定17.difference差分，差别

18.frequency modulation调频

19.frequency divider分频器

20.viewpoint 观点

21.impurity杂质，混合物

22.nanometers纳米

23.packaging封装

24.very large integration 超大规模集成电路

25.digital signal processing数字信号处理

26. baseband 基带

27.binary二进制编码

28.mainframe 主机，大型机

29.electronic mail电子邮件

30.mobile telephone service移动电话业务

二、英译汉

1.A serial link is often used to attach a computer to a modem.

答案：串口通常用来将计算机和调制解调器连接起来。

2.In the data communications world, data generally are defined as information that is stored in digital form.

答案：在数据通信领域，数据通常定义成以数字形式存储的信息。

https://www.360docs.net/doc/3c6846468.html,rmation that has been processed, organized, and stored is called data.

答案：经过处理、组织和存储的信息成为数据。

4.Modern communication systems use digital modulation techniques.

答案：现代通信系统采用的是数字调制技术。

5.Digital modulation offers many advantages over analog modulation.

答案：数字调制比模拟调制有更多的优点。

6.In a digital communication system, in order to increase noise immunity, it is necessary to increase the signal power.

答案：在数字通信系统中，为了增加抗噪性能，需要提高信号的功率。

7.The idea of communication by light probably goes back to signal fires on prehistoric hilltops.

答案：用光来通信的想法大概可追溯到史前的山顶上的信号火。

8.Phase modulation(PM) and frequency modulation(FM) are special cases of angle modulated signaling.

答案：相位调制和频率调制是角度调制信号传输的特例。

https://www.360docs.net/doc/3c6846468.html,rmation signals are transported between a transmitter and a receiver over some form of transmission medium.

答案：信息信号通过某种介质在发射机与接收机之间传送。

10.AM modulators are nonlinear devices with two inputs and one output.

答案：幅度调制器是有两个输入和一个输出的非线性器件。

11.The fundamental purpose of an electronic communication system is to transfer information from one place to another.

答案：电子通信系统的基本作用是把信息从此地传送到彼地。

（1）Integrated circuits are more of a science,than of a technology.

答案：集成电路与其说是技术，不如说是科学。

（2）The bandwidth of an information signal is the difference between the highest and lowest frequencies contained in the information,and the bandwidth of a communications channel is the difference between the highest and lowest frequencies that the channel will allow to pass through it. 答案：信息信号的带宽就是信息中包含的最高和最低频率之间的频差，通信信道的带宽是可通过该信道的最高和最低频率之差。

（3）In its simplest form,a waveform generator is an oscillator circuit that generates well-defined,stable waveforms that can be externally modulated or swept over a given frequency range.

答案：在最简单的情况下，波形发生器就是一个震荡器，他产生预定的稳定波形，然后再进行调制，或在给定的频率范围内扫描。

（4）In order to reduce the effect of frequency error distortion in telephone system,we have to limit the frequency error to 2-5 HZ.

答案：为了减轻电话系统中的频率误差的影响，我们必须将误差控制在2-5赫兹。

（5）Probably the most significant advantage of angle modulation transmission (FM and PM) over amplitude modulation transmission is noise immunity.

答案:与幅度调制传输相比，角度调制传输（FM和PM）最主要的优点是抗噪声性能好。（6）Because laser wavelength is temperature-sensitive,the control circuits also monitor temperature and control coolers when they are included.

答案：因为激光波长队温度敏感，控制电路需要监控温度，如果有冷却器的话，还要控制他们。

（7）The simplest digital modulation techniques is digital amplitude modulation,which is simply double-sideband,full-carrier amplitude modulation where the input modulating signal is a binary waveform.

答案：最简单的数字调制技术上数字调幅，这种技术是简单的双边带，全载波幅度调制，只

是输入的调制信号是二进制波形。

（8）One disadvantage of echoplex,however,occurs when a transmitted character has been received correctly,then a transmission error occurs while it is being sent back to the originator.

答案：当传送的字符已经正确接收，但是在回送的时候却发生了传输错误，这时就会造成一次不必要的重传，这就是回送的一个缺点。

（9）The key innovation in telephony are circuits switching,digitization,separation of call control from voice transfer ,optical links,and service integration.

答案：电话技术中关键的革新有电路交换、数字化、语音传输与呼叫控制的独立、光链接以及综合业务。

（10）Transmissions from base stations to mobile units are called forward links and transmissions from mobile units to base stations are called reverse links.

答案：基站到移动电话之间的传输称为前向链路，而移动电话到基站之间的传输则称为反向链路。

三、汉译英

1.数字计算机本质上是记录数字、运算数字和给出数字形式的结果的机器。

2.带宽越宽，传送时间越长，系统传送的信息就越多。

3.发射机和接收机之间各种扫描的同步，借助于消隐期间传送的专用同步脉冲来完成。

4.在通信系统中，如果接收到的（平均）信号功率，与（平均）噪声功率相比足够大，信息就可以恢复。

5.调幅是这样的过程，它使频率相当高的载波信号的幅度与调制信号（信息）的瞬时值成比例地变化。

6.任何本振信号相对于载波的频率或者相位误差，都会引起调解信号的失真。

7.在解调过程中使用限幅器，FM和PM解调器能够减小噪声电平，改善信噪比。

8.解复用器必须可靠地分离光信道，确保一个信道对邻近信道的低泄露。

9.数据通信中，必须实现四种类型的同步：位或时钟同步、调制解调器或载波同步、字符同步以及报文同步。

10.模拟蜂窝信道可以用FM传输语音，也可以用二进制FSK传输数字信令信息。当传输数字信令信息时，禁止传输语音信号。

答案：

1. Digital computers are essentially machines for recording numbers,operating with numbers and giving the result in numberical forms.

2. The wider the bandwith and the longer the time of transmission,the more information can be conveyed through the system.

3. Synchronization between the various scanning operations at both transmitter and receiver is accomplished by means of special pulses that are transmitted during the blanking periods.

4. In communication systems, if the received (average) signal power is sufficiently large compared to the (average) noise power, information may be received.

5. Amplitude modulation (AM) is the process of changing the amplitude of a relatively hign frequency carrier signal in proportion with instantaneous value of the modulating signal (information).

6. Any error in the frequency or the phase of the local oscillator signal in the receiver, whth respect to the carrier wave, gives rise to distortion in the demodulated signal.

7. With the use of limiters, FM and PM demodulators can actually reduce the noise and improve the signal-to-noise ratio during the demodulation pocess.

8. Demultiplexers must reliably separate the optical channels, with low leakage of lignt from one

optical channel into an adjacent channel.

9. In data communications, there are four types of synchronization that must be achived: bit or clock synchronization,modem or carrier synchronization, character synchronization, and message synchronization.

10. Analog cellular channels carry both voice using FM and digital signaling information using binary FSK. When transmission digital signaling information, voice transmissions are inhibited.

1.频移的大小等于两个正交振荡器的频率差。

2.这种在解调过程中由于频率误差而产生的失真是SSB系统独有的。

3.任何本信号相对于载波的频率或者相位误差，都会引起解调信号的失真。

4.为了减轻电话系统中的频率误差的影响，我们必须将误差控制在2 ~5赫兹。

5.可以采用锁相环电路来实现较高频率的正交振荡器。

6.在数据通信领域,数据通常定义成以数字形式存储的信息。

7.现代通信系统采用的是数字调制技术。

8.无线是无线电系统的一个基本的部件，是提供发射或接收无线电波的一种装置。

9.电磁波在自由空间的传播通常叫射频（RF）转播或为无线电传播。

10.传输线可以分为平衡式的喝非平衡式的两种。

答案：

1. The amount of frequency shift is equal to the absolute value of the difference between the frequencies of the quadrature oscillator.

2. This type of distortion caused by frequency error in the demodulation process is unique to SSB modulation system.

3. Any error in the frequency or the phase of the local oscillator signal in the receiver ,with respect to the carrier wave,gives rise to distortion in the demodulated signal.

4. In order to reduce the effect of frequency error distortion in telephone systems,we have to limit the frequency error to 2-5Hz.

5. A phase-lock-loop(PLL)circuit can be implemented that will give a higher frequency quadrature oscillator.

6. In the data communications world,data generally are defined as information that is stored in digital form.

7. Modern communication systems use digital modulation techniques.

8. The radio antenna is an essential component in any radio system,a radio antenna is a device that provides a means for radiating or receiving radio waves.

9. Free-space propagation of electromagnetic waves is often called radio frequency (RF)propagation or simply radio propagation.

10. Transmission lines can be generally classified as balanced or unbalanced.

四、填空

1.Both --—(发射机) and --—(接收机) have finite --—(上升时间) that limit their --—(带宽)，and their effects must be included when calculating the maximum --——(数据率)。All the --—（波长）in a --—(密集波分复用) system can be--—(放大) using one --—（掺饵光纤放大器）。

答案：transmitters；receivers；rising time；bandwidth；data rate；wavelengths；dense-WDM；amplified；erbium-doped fiber amplifiers

2.AM vestigial sideband(VSB) is a form of --——(幅度调制) in which the --—— (载波) and one complete

sideband are transmitted, but only part of the second sideband is transmitted. In VSB, the lower modulating-signal frequencies are transmitted --——(双边带) and the higher modulating-signal

frequencies are transmitted --——(单边带)。Consequently, the low-frequency modulating signal are

(加重) and produce larger-amplitude signals in the --——(解调器) than the high --——

frequencies.

答案：amplitude modulating；carrier；double band；single band；emphasized；demodulator

3. Although the fundamental concepts and principles of --——-(电子通信) have changde little since their inception, the methods and circuits used to implement them have undergone considerable change.In recent years, --——(晶体管) and --—（线性集成电路）have simplified the design of electronic communications circuits, thus allowing for --——-(小型化), improved performance and --——-(可靠性), and reduced overall costs. In recent years, there has been an

(汹涌澎湃的) need for more and more people to communicate with each other. This --——

tremendous need has stimulated a monumental growth in the electronic --——(通信行业).

Modern electronic communications systems include metallic --——(电缆系统), --——(微波) and

(卫星) radio systems, and optical --—— (光纤系统).

--—

答案：electronic communications；transistors；linear integrated circuits；Miniaturization；reliability；overwhelming；communications industry；cable systems；microwave；satellite；fiber systems 4.AM modulators are --—(非线性器件) with two inputs and one output. One input is a single, --—（高频）carrier signal of constant --—（幅度、射程）and the second input is comprised of relatively low-frequency information signals which may be a --——（单频）or a --——（复杂）--—（波形）made up of many frequencies. Frequencies that are high enough to be --—（有效）radiated by an --—（天线、触角）and propagated through free space are commonly called --—（射频、无线电频率）, or simply RFs. In the --—（调制器）, the information acts on or modulates the RF carrier producing a modulator waveform. The --—（信息、消息）signal may be a single frequency or more likely consist of a range of frequencies. For example, typical

（语音级的通信系统）utilize a range of information frequencies between 300Hz and 3000Hz. --—

The modulated output waveform from an AM modulator is often called an AM --—（包

络）.

答案：nonlinear devices；high-frequency；amplitude；single frequency；Complex；waveform；efficiently；

antenna；radio frequencies；Modulator；information；voice-grade communications systems；envelope

5. The --—(鉴频法) may be to generate an SSB wave when the baseband (i. e. , the band of significant frequencies in the --—（调制信号）) is --—(受限的、带限的) and appropriately related to the carrier frequency. Under these conditions the --—（理想边带）will appear in a

（不相重叠的）interval in the --——（光谱）in such a way that it may be selected by --—

an appropriate --—（滤波器）. Thus an SSB modulator base on frequency discrimiation --—（基本组成）of a product modulator (e. g. , ring modulator) and a filter which is designed to pass the desired sideband of the --—（抑制载波双边带调制）wave at the modulator output and reject the other sideband. A block --—（图表）of this modulator is shown in --—（数字）7-3. The most severe --—（要求）of this method of SSB generation usually arises from the unwanted sideband, the nearest frequency component of which is --—（分开）the desired sideband by twice the lowest frequency component of the modulating wave.

答案：frequency discrimiation method；modulating wave；restricted；desired sideband；nonoverlapping；

spectrum；filter；consists basically；DSBSC；diagram；Figure；requirement；separated from；

6.-——-（当频谱密度为常数的热噪声）is added to an --—（调频）signal, it produce an unwanted

（偏移）of the --—（载波频率）. The magnitude of this frequency deviation depends on the --—

（噪声的相对幅度）with respect to the carrier. When this unwanted carrier is --——（解调）, --——

it becomes noise if it has --——-（频率成分）that fall within the information-frequency spectrum.

The --——（解调噪声的频谱形状取决于）whether an FM or PM demodulator is used. The noise voltage at the output of a PM demodulator is constant with frequency, --——--——（而FM解调器输出端的噪声电压随频率线性增加）. This is -——--—（通常称作）the FM noise triangle.

答案：When thermal noise with a constant spectral density，FM ，deviation ，carrier frequency ，relative amplitude of the noise ，demodulated，frequency component ，spectral shape of the denodulated noise depend on ，whereas the noise voltage at the output of an FM demodulator increases linearly with frequency ，commonly called

7.--——--(系统机构) for GSM consists of three primary subsystems that interact among one another and with subscribers through --——--（专门的网络接口）. The three primary subsystems of GSM are --—（基站子系统）（BSS）, --——（网络）and --——-（交换子系统）（NSS）, and --——（操作支持子系统）. Although the mobile station is technically another subsystem, --——--（通常认为它是基站子系统的一部分）.

答案：The system architecture ，specified network interfaces ，Base Station Subsystems ，Network ，Switching Subsystems ，Operational Support Subsystem ，it is generally considered to be part of the base station subsystem

8.--—(在接收机中), the data on the π/4 QPSK signal can be easily detected by using -——-（FM检波器）, followed by -——（可重置积分器）over a symbol (2-bit) period. The FM detector produces ——--—（相位的倒数）, and the integrator evaluates ——（相移）occurs over the symbol interval.-———（结果为4个可能相移中的一个）, ±45?and ±135?. For example, if the detected phase shift at the integrator output is -45?,——-——（对应检测到的数据就是10）. Data on the π/4 QPSK signal can also be detected by using baseband IQ processing or by using

（差分检测）at the IF.—--—（计算机仿真）indicate that all three of these receiver structures —--—

have almost the same BER error performance [ Anvari and Woo, 1991 ].—--——（在一个加性高斯白噪声信道中）, the BER performance of --—（三种差分（非相干）检波器）is about 3 dB inferior to that of QPSK, but coherently detected π/4 QPSK has the same BER as QPSK.

（对于非矩形数据脉冲）, the AM on π/4 QPSK is less than that on QPSK, since -——（最——

大相移）for π/4 QPSK is 135?, compared with 180?for QPSK. However, π/4 QPSK is easy to detect and has been adopted for use in TDMA———--（蜂窝电话系统）

答案：At the receiver ，an FM detector ， a resettable integrator ，the derivative of the phase ，the phase shift that ，The result is one of the four possible phase shifts ，the corresponding detected data are 10 ，differential detection ，Computer simulations ，In an A WGN channel ，the three differential ( noncoherent ) detectors ，For the case of nonrectangular data pulses ，the maximum phase shift ，cellular telephone systems

9．Long-range communication in the (高频段) high-frequency band is possiblebecause of (折射) refraction

in a region of the upper(大气层)atmosphere called the (电离层) ionosphere, where some of the air (分子) molecules are(电离) ionized by(太阳辐射) sun radiant .In Earth's atmosphere, ray-wavefront propagation may be altered from ( 自由空间)free-space behavior by optical effects such as ( 折射) refraction , ( 反射)reflection, (衍射)diffraction , and(干涉) interference .

五、文章翻译

1．Speech and Music

The telecommunications environment is dominated by four important sources of information: Speech, music, picture, and computer data. A source of information may be a characterized in terms of the signal that carries the information. A signal is defined as a single-valued function of time that plays the role of the independent variable; at every instant of time , the function has a unique value. The signal can be one-dimensional, as in the case of speech ,music, or computer data; two-dimensional, as in the case of pictures; three dimensional, as in the case of video data; and four-dimensional , as in the case of volume data over time. In the sequel, we elaborate on different sources of information.

翻译：电信环境主要有四种信息源：语音、音乐、图像和计算机数据。信息源的特性可有携带此信息的信号来表征。信号定义为一时间做自变量的单值函数；即在每一时刻，函数具有唯一的值。信号可以使一维的，例如语音、音乐和计算机数据；也可以是二维的，例如图像；也可以是三维的，例如视频数据；还可以是四维的，例如随时间变化的立体空间数据。下面，我们详细地说明各种信息源。

2．Basic Cellular T elephone Concepts

The basic concept of cellular telephone is quite simple. The FCC originally defined geographic cellular radio coverage areas based on modified 1980 census Figures. With the cellular concept ,each area is further divided into hexagonal-shaped cells that fit together to form a honeycomb pattern as shown in Figure 20-1. The hexagon shape was chosen because it provides the most effective transmission by approximating a circular pattern, while eliminating gaps inherently present between adjacent circles . A cell is defined by its physical size and, more importantly , by the size of its population and traffic patterns. The number of cell per systems is not specifically defined by the FCC and has been left to the provider to establish in accordance with anticipated traffic patterns. Each geographical area is allocated a fixed number of cellular voice channels. The physical size of a cell varies depending on the user density. For example, macrocells typically have a radius of between 1 mile and 15 mile with output power levels of between 1 watt and 20 watts. Microcells typically have a radius between a few feet and several hundred feet with output power levels of between 0.1 watt and 1watt. Microcells are used most often in cities , where they can appear on the streets and inside building. By virtue of their low effective working radius, microcells exhibit milder propagation impairments such as reflections and signal delays. Macrocells may overlay microcell clusters with slow-moving mobile units using the microcells and faster moving units using macrocells. The mobile unit will be able to identify itself as either fast or slow mobbing, thus allowing it to do fewer cell transfers and location updates . Cell transfer algorithms can be modified to allow for the small distance between a mobile units and its microcellular base station.

Cellular telephone is an intriguing mobile radio concept that calls for replacing a single, high-powered fixed base station transmitter located high above the center of a city with multiple , low –powered duplicates of the diced infrastructure distributed over the coverage area on sites placed closer to the ground. The cellular concept adds a spatial dimension to the simple cable-trunking model of typical wireline telephone systems.

翻译：蜂窝电话的基本概念很简单。FCC最初是根据1980年修订的人口数据来定义无线蜂窝地理覆盖区域的。有了封我的概念，每个区域被分割成六边形小区，其形状类似于图20.1所示的蜂窝状结构。选择六边形是因为它近似于圆形，可以提供非常有效的传输，同时还可以消除相邻圆之间的缝隙。小区是根据其物理尺寸来划分的，更主要的是根据人口和交通情况来决定。系统中小区的数量并不是由FCC规定的，而是留给服务提供商，由服务提供根据预计的交通方式来确定。每个地理区域都分配了固定数量的蜂窝语音信道。一个小区的物理空间的大小取决于其用户的密度情况。例如，典型的宏小区半径为1~15英里，发

射功率在1~20瓦之间。典型的微小区半径在几英尺到几百英尺，而发射功率在0.1-1瓦之间。微小区通常用于城市的街道和建筑物内。利用其有效工作半径小的有优点，微小区可以降低反射和信号延迟等传播中的损伤。宏小区可以覆盖拥有慢速移动终端的微小区和拥有快速移动终端的宏小区。移动终端能够区分本身是快速移动还是慢速移动，这样可以进行小量的越区切换和位置更新。当移动终端和微小区基站间的距离短的时候可以对越区切换算法进行修改。

蜂窝电话是一个非常巧妙的移动无线电的概念，使用多个小功率、在覆盖区域中结构固定、接近地面的发射机就可以替代一个高立在城市中心的大功率、固定基站的发射机。对典型的有线电话系统的简单电缆中继模式，蜂窝技术加入了空间的概念。

3. Pictures

The third source of information ，pictures，relies on the human visual system for its perception. The picture can be dynamic，as in television ，or static ，as in facsimile .Taking the case of television first，the pictures in motion are converted into electrical signals to facilitate their transport from the transmitter to the receive. To do

so ，each complete picture is sequentially scanned. The scanning process is carried out in a TV camera . In a black-and-white TV ，the camera contain optics designed to focus an image on a photocathode consisting of a large number of photosensitive elements .The charge pattern so generated on the photosensitive surface is scanned by an electron beam ，thereby producing an output current that varies temporally with

the way in which the brightness of the original picture varies spatially from one point to another . The resulting output current is called video signal . The type of scanning used in television is a from of spatial sampling called raster scanning ，which converts a two-dimensional image intensity into one-dimensional waveform ；it is somewhat analogous to the manner in which we read a printed paper in that the scanning is performed from left to right on a line-by-line basis . In North American analog television ，a picture is divided into 525 lines ，which constitute a frame. Each frame is decomposed into two interlaced fields ，each of which consists of 262.5 lines . For convenience of presentation，we refer to the two fields as I and II . The scanning procedure is illustrated in Figure 2-1 ，The lines of field I are depicted as solid lines ，and those of field II are depicted as dashed lines . The start and end of each field are also included in the figure . Field I is scanned first .The scanning spot of the TV camera moves with constant velocity across each line of the field from left to right , and the image intensity at the center of the center of the spot is measured ; the scanning spot itself is particular line is reached , the scanning spot quickly flies back(in a horizontal direction) to the start of the next line down in the field . This flyback is called horizontal retrace . The scanning process described here is continued until the whole field has been accounted for. When this condition is reached , the scanning spot moves quickly (in a vertical direction) from the end of field I to the start of field II. This second flyback is called the vertical retrace. Field II is treated in the same fashion as field I.

翻译：图像

图像，第三种信息源，由人的视觉系统所感知。图像可能是动态的，例如电视；也可能是静态的，例如传真。先来看电视的情况，活动图像转换成信号以便从发射机传送到接收机。为此，每幅图像需顺序扫描。扫描过程是由电视摄像机完成的。在黑白电视机中，摄像机的光学透镜把图像聚焦到由大量光敏元件组成的光电阴极上。由此在光电阴极表面产生电荷图像。电子束对电荷图像扫描，从而把原图像点到点的空间亮度变化转换成输出电流的时间变化。这种输出电流称为视频信号。电视用的扫描时一种称为栅格扫描的空间取样形式，它把二位的图像转换为一维波形，类似于我们阅读印刷品时的逐行从左到右的扫描。在北美，模拟电视的一幅图像被分为525行，称为一帧，每一帧又分为两个交替的场，每场有262.5行。为了便于说明。我们不妨把它们称为I场和II场。扫描的过程示于图2-1。I场的各行用实线表示，II场用虚线。每一场的起点和终点亦标注在图上。首先扫描I场。电视摄像机的扫描点沿该场的每行从左至右恒速地移动，并测出点心的图像亮度；扫描点部分地起到了图像局部区域的平均作用。当该场的某一行扫描完成，扫描点快速地沿水平方向飞返到下一行起点。这种飞返的过程称为水平回程。上述扫描过程持续下去，直到整个场被扫完。当I场扫完后，扫描沿着垂直方向快速地从I场终点到II场起点，这称为垂直回程。II 场的扫描类于I场。