电信专业英语期末试卷A及部分答案 - 图文

20 07 －20 08 学年 第 1 学期 考 生 信 息 栏 系 专业 级 班级 姓名 学号 课程名称 专业英语 试卷 卷别 A √ B □ 专业 级 班级 装 订 线 考试 闭卷 √ 方式 开卷 □ 本试卷共 八 大题( 6 页)，满分100分，考试时间120分钟。 请在答题纸上作答，在试卷上作答无效。 一、根据英文单词或词组，写出中文意思（本题共15小题，每题1分，共15分） 1. Semiconductor 半导体 2. amplitude 振幅 3. simultaneous 同时 4. slot 槽 5. protocol 协议 6. Bandwidth 带宽 7. Coaxial 同轴 8. Decode解码 9. harmonic 谐波 10. Geostationary 地球静止轨道 11. flip-flop 触发器 12. uplink frequency spectrum 上行链路的频谱 13. peak-to-peak value 峰—峰值 14. home appliance 家电 15. distributed system 分布式系统 第 1 页 共 6 页

二、根据英文缩写，写出英文完整形式及中文意思（本题共5小题，每题2分，共10分） 1. ATM 自动取款机 2. WAN 广域网 3. ISDN 整体服务数位网路 4. ISO 国际标准组织 5. PCM 脉冲编码调制 三、用连线使A栏与B栏匹配 （本题共2大题，每题5分，共10分） 1. Column A Column B (1) LAN (a) an international standards organization (2) WAN (b) a network that provides communications across country or the entire world. (3) host computer (c) a station which is used to receive and retransmit microwave signals. (4) ISO (d) a computer which is located on a network and provides services to other nodes connected to the network. (5) Microwave relay (e) a network that provides communications within specific buildings or facilities. 2. Column A Column B (1) voice channel (a) one of the typical mobile communication systems (2) MSC (b) the medium used to carry calls from one point to another (3) PSTN (c) radio station used within mobile communications for transmission to mobiles or to other base stations (4) BS (d) public network which provides dial-up(拨号)access and has been primarily designed to carry voice (5) CMS (e) an interface between the radio system and the PSTN, where calls to and from the mobile subscribers are switching 四、选择适当的词或词组填空 （本题共5空，每空1分，共5分） 第 2 页 共 6 页

1. The current which flows through RL______ (is equal to, equals to) the input voltage

Ui divided by Ri. 2. The switch, resistor and wire______ (are composed of, constitute) a circuit. 3. The use of mobile telephone is quite ______ (familiar with, familiar to) us in our daily lives. 考 生 信 息 栏 系 专业 级 班级 姓名 学号 4. ATM retains(保留)all the flexibility(灵活性)of packet mode, _____(enabling, enable) only required information _____ _ (to be conveyed, convey). 五、选择适当的词填空 （本题共5小题，每题1分，共5分） 装 订 线 1. The word “multimedia” is ______ describe a mixture(混合)of hardware, software and applications. A. being used to B. used C. using to 2. The pulse is composed of _____ states. A. one B. two C. three 3. ATM transfer information ____ short packets called “cells”(信元) _____ a fixed length of 48 bytes plus five heads bytes. A. of, in B. in, with C. to, for 4. The function of the optical detector is to ______. A. convert optical signal to electrical signal B. convert electrical signal to optical signal C. the electrical signal is applied to it 5. Each channel unit in the BS is equipped _____ radio transmitter, radio receiver, and control unit. A. in B. with C. by 六、阅读理解 （本题共5小题，每题3分，共15分） (1) Integrated Circuit Integrated circuit, or IC is a combination of a few interconnected circuit elements such as transistors, diodes, capacitors, and resistors produced in a single manufacturing process on one and the same bearing structure, called the substrate, and intended to perform definite function involved in converting information. The electrically interconnected components that make up an IC are called integrated elements. If an integrated circuit includes only one type of components, such 第 3 页 共 6 页

as only diodes or resistors, it is said to be an assembly or set of components. The principle of integrated circuit elements lies in the following. A great number of “set” are produced simultaneously on a wafer. Each set contains all the components such as transistors, diodes, and resistor which are interconnected with short fine metallic stripes deposited on the wafer surface. They make up an functional block. Each ICs of components is a ready integrated circuit. All ICs are regularly distributed on the wafer surface. ICs can be classified by function into two: circuits to be applied in digital systems and those to be applied in linear systems. The digital ICs are employed mostly in computers, electronic counters, frequency synthesizers and digital instruments. And the analog, or linear ICs operate over a continuous range, and include such devices as operational amplifiers. The invention of IC is a great revolution in the electronic industry. Sharp size, weight reductions are possible with these techniques; and more importantly, high reliability, excellent functional performance, low cost and low power dissipation can be achieved. Questions for text: 1. What types of elements may integrated circuits possibly include? 2. Tell some advantages of using integrated circuits. (2)Pulse-Code Modulation Pulse-Code Modulation (PCM) is the most basic form of digital pulse modulation. In pulse-code modulation, a message signal is represented by a sequence of coded pulses, which is accomplished by representing the signal in discrete form in both time and amplitude. The basic operations performed in the transmitter of PCM are sampling, quantizing, and encoding. The quantizing and encoding operations are usually performed in the same circuit, which is called analog-to-digital converter. The basic operations in the receiver are regeneration of impaired signals, decoding, and reconstruction of the train of quantized samples. In what follows, we describe the various operations that constitute a basic PCM system. Sampling. The incoming message signal is sampled with a train of narrow rectangular pulses. Quantization. The sampled version of the message signal is then quantized, thereby providing a new representation of the signal that is discrete in both time and amplitude. Encoding. Any plan for representing each of this discrete set of sample values as a group of particular binary numbers is called encoding. Regeneration. The most important feature of PCM systems lies in the ability to control the effects of distortion and noise produced by transmitting a PCM signal through a channel. This capability is accomplished by reconstructing the PCM signal by means of a chain of regenerative repeaters located 第 4 页 共 6 页

sufficiently close spacing along the transmission route. Decoding. The decoding process involves generating a pulse, the amplitude of which is the linear sum of all the pulses in the code word, with each pulse being weighted by its place value (20,21,22,…,2R-1) in the code, where R is the number of bits per sample. 考 生 信 息 栏 系 专业 级 班级 姓名 学号 Filtering. The final operation in the receiver is to recover the message signal by passing the decoder output through a low-pass filter whose cutoff frequency is equal to the message bandwidth W. Questions for text: 1. What is “PCM” short for? 装 订 线 2. What are the basic operations performed in the transmitter of PCM? 3. What are the basic operations performed in the receiver of PCM? 七、将下列英文翻译成中文 （本题共12小题，每题3分，共36分） 1. We shall define voltage “across” an element as the work done in moving a unit charge (+1C) through the element from one terminal to the other. 2. The circuit designers are not generally interested in the internal components of an integrated circuit, but only in the performance of the unit as a whole. 3. A computer consists of an input/output (I/O) device, memory, a control section, and an arithmetic and logic unit (ALU), which is the computational element. 4. Because of ever more powerful computer systems and the experience of creative programmers, multimedia is truly changing the way people are using computers. 5. When a call between a mobile subscriber and an ordinary subscriber has been set up, the speech is transmitted on the radio path between the mobile station and a voice channel unit of the base station situated close to the mobile station. 6. At today’s level of development, the IC might comprise more than ten thousand separate electronic elements including elements of many different functions, such as diodes, transistors, capacitors and resistors. 7. Just as in the decimal system, every time we shift a symbol one place to the left, we multiply its value by the base 2. 8. Unlike many other threats, a computer virus can spread from program to program and from system to system, without direct human intervention(介入). 9. The fiber optic systems do not use a conventional power source and can be more easily used in hazardous(危险的)areas. 第 5 页 共 6 页

10. A multimeter is a general-purpose meter capable of measuring DC and AC voltage, current, resistance, and in some cases, decibels(分贝). 11. This is accomplished by using a process known as demodulation, which is the reverse of the modulation process. 12. Once the message is entirely received, the message processor examines its header, and accordingly decides on the next outgoing channel on which to transmit it. 八、将下列中文翻译成英文 （本题共2小题，每题2分，共4分） 1. 网络的优势在于它能够方便快捷地传递消息。 2. 键盘是最常用的输入设备。

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