光纤通信英文版答案
【篇一：光纤通信英语】
通讯专业术语
adm add drop multiplexer 分插复用器
利用时隙交换实现宽带管理，即允许两个stm-n信号之间的不同vc实现互连，
并且具有无需分接和终结整体信号，即可将各种g.703规定的接口信号(pdh)或
stm-n信号(sdh)接入stm-m(mn)内作任何支路。
有源光网络属于一点对多点的光通信系统，由onu、光远程终端olt和光纤传输 线路组成。
apon atm passive optical network atm无源光网络
一种结合atm 多业务多比特率支持能力和无源光网络透明宽带传送能力的理想
长远解决方案，代表了面向21 世纪的宽带接入技术的最新发展 方向。
adsl asymmetric digital subscriber line 非对称数字用户线 非对称数字用户线系统ＡＤＳＬ是一种采用离散多频音ＤＭＴ线路码的数字用
户线ＤＳＬ系统。
aa adaptive antenna 自适应天线
一种天线提供直接指向目标的波束，比如移动电话的天线，能够随目标移动自
动调整功率等因素，也称为智能天线（smart antenna）。
adpcm adaptive differential pulse code modulation 自适应脉冲编码调制
一种编码技术，将模拟采样的比特数从8位降低到3到4位，完成传输信号的
压缩，itu-t推荐g.721 为32位adpcm定义了一种算法（每秒8000次采样，
每次采样采4比特），与传统pcm编码相比，它的传输容量加 倍。
adfe automatic decree feedback equalizer自适应判决反馈均衡器
一种利用判决后的信号作为后向抽头的输入信号，可以消除噪声对后向抽头信
号的影响的均衡器技术。
ami alternate mark inversion 信号交替反转码
一种数字传输中常用的编码技术，逻辑0由空电平表示，而逻辑1由交替反转
的正负电压表示。
aon all optical net 全光网
就是网中直到端用户节点之间的信号通道仍然保持着光的形式，即端到端的全
光路，中间没有光电转换器。这样，网内光信号的流动就没有光电转换的障碍，
信息传递过程无需面对电子器件处理信息速率难以提高的困难。 aowc all optical wave converter 全光波长转换器
是指不经过电域处理，直接把信息从一个光波长转换到另一个波长的器件。
ask amplitude shift keying 振幅键控 一种键控技术，对应二进制调制信号，承载信号在开启和关闭之间切换，也就 是常说的on-off键控。
atpc automatic transfer power control自动发信功率控制
技术的要点是微波发信机的输出功率在atpc控制范围内自动跟踪接手段接收电
平的变化而变化。它的优点有可减少对相邻系统的干扰、减少上衰减问题、减低直
流功率消耗、改善剩余误码特性、在衰落条件下使输出功率额外增加2db。 awf all wave fiber 全波光纤
消除了光纤1383nm的水峰，这样就在1350－1450nm波段能增加120多个新的 波长（间隔100ghz）。对于城市接入网的用户十分有利。
au administrative unit 管理单元
提供高阶通道层和复用段层之间适配功能的信息结构. aug administrative unit group 管理单元组
由一个或多个在stm-n净负荷中占据固定位置的、确定位置的管理单元组成。
apd avalanche diode 雪崩光电二极管
利用雪崩倍增效应使光电流得到倍增的高灵敏度的探测器。 ba booster(power) amplifier 光功率放大器
可补偿光复用器的损耗，提高入纤功率的光放大器。
bber background block error ratio 背景误块比对于一个确定的测试时间而
言，在可用时间出现的bbe数与扣除不可用时间和ses期间所有块数的总块数 之比。
【篇二：武汉理工大学光纤通信ab卷英文】
e following acronym （10p each 1p） 1) imd 2) scm 3) aotf 4) ra 5) spm 6) hfc 7) otdm 8) tw 9) scm 10) dbr
3. filling blanks (20p each 1p)
1) the main cause of intrinsic absorption in the infrared region is ( ).
2 2) stm-1 frames provide a transmission bit rate of ( ). 3) the sensitivity of a photo detector in an optical fiber communication system is describable in terms of ( ).
4) according to whether there is electric or magnetic field in the direction of propagation or not,
transverse modes of light waves are classified into different types: ( ), ( ), ( ) and ( ).
5) please list three steps of sdh multiplexing: ( )，( )，( ).
6) the principal noises associated with photo detectors that have no internal gain are quantum noise,
dark-current noise generated in the bulk material of the photodiode, and ( ).
7) largely due to ( ) and ( ), the optical signals undergo waveform distortion and decreased amplitude.
8) the stm-1 frame is the basic transmission format for sdh. the frame lasts for ( )
microseconds; therefore there are ( ) frames per second.
9) a laser consists of a ( ) inside a highly reflective ( ) as well as a means to supply
energy to the gain medium.
10) ( ) performance and jitter are two important indicators in a optical digital communication system.
11)optical transmitter consists of ( ), a modulator and a channel coupler.
12)list two classes of transmission medium: ( ), ( ). 1．multiple choice (10p each 1p) 1) b2) a3) a 4) d 5) c6) a 7) c8) b
2.write the full name of the following acronym （10p each 1p） 1) imd (intermodulation disortion) 2) scm (subcarrier multiplexing) 3) aotf(acousto-optic tunable filter) 4) ra(raman amplifier)
5) spm (self-phase modulation) 6) hfc (hybrid fiber-coaxial)
7) otdm (optical time-division multiplexing) 8) tw (traveling wave)
9) scm(subcarrier multiplexing)
10) dbr (distributed bragg reflector) 3. filling blanks (20p each 1p)
1) the characteristic vibration frequency of atomic bonds 2) 155 mbit/s
3) the minimum detectable optical power
4) tem modes; te modes; tm modes; hybrid modes 5) mapping; aligning; multiplexing 6) surface leakage current noise 7) attenuation; dispersion
8) 125 ; 8000
9) gain medium ; optical cavityforward 10) ber (the bit error rate)
11) absorption losses; scattering losses; and bending losses 12)optical add drop multiplexer(oadm)
4. give a brief description of following questions (10p each 2p) 1) stimulated emissions: if a photon of energy hv12 impinges on the system while the electron is still in its excited state, the electron is immediately stimulated to drop to the ground state and give off a photon of energy hv12. 2) the main limitations of pdh are:
inability to identify individual channels in a higher-order bit stream;
insufficient capacity for network management; most pdh network management is proprietary;
there is no standardized definition of pdh bit rates greater than 140 mbit/s; and,
there are different hierarchies in use around the world.
specialized interface equipment is required to interwork the two hierarchies.
3)gain saturation: when near saturation, the gain is nonlinear; saturation, the signal cannot be amplified. 4) the disadvantage of raman amplifier:
need large output power pump laser. as raman scattering, the energy is transferred from high frequency to low frequency. cross talk will affect signal.
5) dynamic range: system dynamic range is the maximum optical power range to which any detector must be able to respond. 5. (10p)
6. (10p) ?2cfrom ???，??? obtain: 2ln2ln c3?108
?????81ghz， (5p) 2ln2?500?10?6?3.7 (800?10?9)2
?????0.17nm.?62ln2?500?10?3.7 7. (10p)
the quantum efficiency
number of e-h pairs generated
?= -----------------------------------------(6p) number of incident photons ?2
5.4?106
=?0.90 (4p) 6?106 8. (20p)
according to (2p)
光纤通信英文版答案
