通信工程项目毕业材料外文翻译
通信项目工程规划项目毕业材料外文翻译
用于多跳认知无线电网络的分布式网络编码控制信道Alfred Asterjadhi等著1 前言大多数电磁频谱由政府机构长期指定给公司或机构专门用于区域或国家地区。
由于这种资源的静态分配，许可频谱的许多部分在许多时间和/或位置未使用或未被充分利用。
另一方面，几种最近的无线技术在诸如IEEE802.11，蓝牙，Zigbee之类的非许可频段中运行，并且在一定程度上对WiMAX进行操作;这些技术已经看到这样的成功和扩散，他们正在访问的频谱- 主要是2.4 GHz ISM频段- 已经过度拥挤。
为了为这些现有技术提供更多的频谱资源，并且允许替代和创新技术的潜在开发，最近已经提出允许被许可的设备（称为次要用户）访问那些许可的频谱资源，主要用户未被使用或零星地使用。
这种方法通常被称为动态频谱接入（DSA），无线电设备发现和机会性利用未使用或未充分利用的频谱带的能力通常称为认知无线电（CR）技术。
DSA和CR最近都引起了无线通信和网络界的极大关注。
通常设想两种主要应用。
第一个是认知无线接入（CW A），根据该认知接入点，认知接入点负责识别未使用的许可频谱，并使用它来提供对次用户的接入。
第二个应用是我们在这个技术中研究的应用，它是认知自组织网络（CAN），也就是使用用于二级用户本身之间通信的无许可频谱，用于诸如点对点内容分发，环境监控，安全性等目的，灾难恢复情景通信，军事通信等等。
设计CAN系统比CW A有更多困难，主要有两个原因。
第一是识别未使用的频谱。
在CW A中，接入点的作用是连接到互联网，因此可以使用简单的策略来推断频谱可用性，例如查询频谱调节器在其地理位置的频谱可用性或直接与主用户协商频谱可用性或一些中间频谱经纪人另一方面，在CAN中，与频谱调节器或主要用户的缺乏直接通信需要二级用户能够使用检测技术自己识别未使用的频谱。
第二个困难是辅助用户协调媒体访问目的。
在CW A中存在接入点和通常所有二级用户直接与之通信（即，网络是单跳）的事实使得直接使用集中式媒体接入控制（MAC）解决方案，如时分多址（TDMA）或正交频分多址（OFDMA）。
通信工程毕业设计 外文翻译
东华理工大学长江学院毕业设计外文翻译学生姓名：张伟学号：09323119专业：信息工程系别：信息工程指导教师：谌洪茂职称：讲师二0一三年六月五日OriginalOptical Fiber CommunicationsThe General System Communication may be broadly defined as the transfer of information from one point to another. When the information is to be conveyed over any distance a communication system is usually required. Within a communication system the information transfer is frequently achieved by superimposing or modulating the information onto an electromagnetic wave which acts as a carrier for the information signal. This modulated carrier is then transmitted to the required destination where it is received and the original information signal is obtained by demodulation. Sophisticated techniques have been developed for this process by using electromagnetic carrier waves operating at radio frequencies as well as microwave and millimeter w ave frequencies. However, ‘communication’ may also be achieved by using an electromagnetic carrier which is selected from the optical range of frequencies.An optical fiber communication system is similar in basic concept to any type of communication system.The communication system therefore consists of a transmitter or modulator linked to the information source, the transmission medium,and a receiver or demodulator at the destination point. In electrical communications the information source provides an electrical signal, usually derived from a message signal which is not electrical (e.g. sound), to a transmitter comprising electrical and electronic components which converts the signal into a suitable form for propagation over the trans-mission medium. This is often achieved by modulating a carrier, which, as mentioned previously, may be an electromagnetic wave. The transmission medium can consist of a pair of wires, a coaxial cable or a radio link through free space down which the signal is transmitted to the receiver, where it is transformed into the original electrical information signal (demodulated) before being passed to the destination.However, it must be noted that in any transmission medium the signal is attenuated, or suffers loss, and is subject to degradations due to contamination by random signals and noise, as well as possible distortions imposed by mechanisms within the medium itself. Therefore, in any communication system there is a maximum permitted distance between the transmitter and the receiver beyond which the system effectively ceases to give intelligible communication. For long-haul applications these factors necessitate the installation of repeaters or line amplifiers atintervals,both to remove signal distortion and to increase signal level before transmission is continued down the link.For optical fiber communications system shown in Figure (a) may be considered in slightly greater detail, as given in Figure (b).Fig(a) The general communication system(b)The optical fiber communication systemIn this case the information source provides an electrical signal to a transmitter comprising an electrical stage which drives an optical source to give modulation of the light wave carrier. The optical source which provides the electrical–optical conversion may be either a semiconductor laser or light-emitting diode (LED). The transmission medium consists of an optical fiber cable and the receiver consists of an optical detector which drives a further electrical stage and hence provides demodulation of the optical carrier. Photodiodes (p–n, p–i–n or avalanche) and, in some instances, phototransistors and photoconductors are utilized for the detection of the optical signal and the optical–electrical conversion. Thus there is a requirement for electrical interfacing at either end of the optical link and at present the signal processing is usually performed electrically.The optical carrier may be modulated using either an analog or digital information signal. In the system shown in Figure (b) analog modulation involves the variation of the light emitted from the optical source in a continuous manner. Withdigital modulation,however, discrete changes in the light intensity are obtained (i.e. on–off pulses).Although often simpler to implement, analog modulation with an optical fiber communication system is less efficient, requiring a far higher signal-to-noise ratio at the receiver than digital modulation. Also, the linearity needed for analog modulation is not always provided by semiconductor optical sources, especially at high modulation frequencies. For these reasons,analog optical fiber communication links are generally limited to shorter distances and lower bandwidth operation than digital links.Figure (c) shows a block schematic of a typical digital optical fiber link. Initially, the input digital signal from the information source is suitably encoded for optical transmission. The laser drive circuit directly modulates the intensity of the semiconductor laser with the encoded digital signal. Hence a digital optical signal is launched into the optical fiber cable. The avalanche photodiode (APD) detector is followed by a front-end amplifier equalizer or filter to provide gain as well as linear signal processing and noise bandwidth reduction.Fig(c)A digital optical fiber link using a semiconductor laser source and an avalanche photodiode(APD) detectorFinally, the signal obtained is decoded to give the original digital information. However, at this stage it is instructive to consider the advantages provided by light wave communication via optical fibers in com-parison with other forms of line and radio communication which have brought about the extensive use of such systems in many areas throughout the world.译文光纤通信一般来说把信息从一点传送到另一点就称为通信。
通信工程专业英语课文翻译
Technology of Modern CommunicationText A: BluetoothBluetooth wireless technology is a short-range communications technology intended to replace the cables connecting portable（轻便的）and fixed devices while maintaining high levels of security.The key features of Bluetooth technology are robustness（稳健）, low power, and low cost .The Bluetooth specification defines a uniform structure for a wide range of devices to connect and communicate with each other.蓝牙无线技术是一种小范围无线通信技术，旨在保持高安全级的基础上，在便携式设备与固定设备之间实现无线连接。
蓝牙技术的主要特点是稳健，低功耗和低成本。
蓝牙规范定义了一个统一的结构，适用范围广的设备连接并相互沟通。
Bluetooth technology has achieved global acceptance such that any Bluetooth enable device, almost everywhere in the world, can connect to other Bluetooth enabled devices in proximity. Bluetooth enabled electronic devices connect and communicate wirelessly through short-range, ad hoc（特别）networks known as piconets Each device can simultaneously communicate with up to seven other devices within a single piconet. Each device can also belong to several piconets simultaneously. Piconets are established dynamically and automatically as Bluetooth enabled devices enter and leave radio proximity.蓝牙技术已取得全球认可，使得任何支持蓝牙的设备，几乎在世界各地，可以连接到其他支持蓝牙的邻近装置。
数据通信 毕业论文外文文献英文翻译
郑州轻工业学院本科毕业设计（论文）——英文翻译题目差错控制编码解决加性噪声的仿真学生姓名专业班级通信工程05-2 学号 12院（系）计算机与通信工程学院指导教师完成时间 2009年4月26日英文原文:Data communicationsGildas Avoine and Philippe OechslinEPFL, Lausanne, Switzerlandfgildas.avoine, philippe.oechsling@ep.chAbstractData communications are communications and computer technology resulting from the combination of a new means of communication. To transfer information between the two places must have transmission channel, according to the different transmission media, there is wired data communications and wireless data communications division. But they are through the transmission channel data link terminals and computers, different locations of implementation of the data terminal software and hardware and the sharing of information resources.1 The development of data communicationsThe first phase: the main language, through the human, horsepower, war and other means of transmission of original information.Phase II: Letter Post. (An increase means the dissemination of information)The third stage: printing. (Expand the scope of information dissemination)Phase IV: telegraph, telephone, radio. (Electric to enter the time)Fifth stage: the information age, with the exception of language information, there are data, images, text and so on.1.1 The history of modern data communicationsCommunication as a Telecommunications are from the 19th century, the beginning Year 30. Faraday discovered electromagnetic induction in 1831. Morse invented telegraph in 1837. Maxwell's electromagnetic theory in 1833. Bell invented the telephone in 1876. Marconi invented radio in 1895. Telecom has opened up in the new era. Tube invented in 1906 in order to simulate the development of communications.Sampling theorem of Nyquist criteria In 1928. Shannong theorem in 1948. The invention of the 20th century, thesemiconductor 50, thereby the development of digital communications. During the 20th century, the invention of integrated circuits 60. Made during the 20th century, 40 the concept of geostationary satellites, but can not be achieved. During the 20th century, space technology 50. Implementation in 1963 first synchronized satellite communications. The invention of the 20th century, 60 laser, intended to be used for communications, was not successful. 70 The invention of the 20th century, optical fiber, optical fiber communications can be developed.1.2 Key figuresBell (1847-1922), English, job in London in 1868. In 1871 to work in Boston. In 1873, he was appointed professor at Boston University. In 1875, invented many Telegram Rd. In 1876, invented the telephone. Lot of patents have been life. Yes, a deaf wife.Marconi (1874-1937), Italian people, in 1894, the pilot at his father's estate. 1896, to London. In 1897, the company set up the radio reported. In 1899, the first time the British and French wireless communications. 1916, implementation of short-wave radio communications. 1929, set up a global wireless communications network. Kim won the Nobel Prize. Took part in the Fascist Party.1.3 Classification of Communication SystemsAccording to type of information: Telephone communication system, Cable television system ,Data communication systems.Modulation by sub: Baseband transmission,Modulation transfer.Characteristics of transmission signals in accordance with sub: Analog Communication System ,Digital communication system.Transmission means of communication system: Cable Communications,Twisted pair, coaxial cable and so on.And long-distance telephone communication. Modulation: SSB / FDM. Based on the PCM time division multiple coaxial digital base-band transmission technology. Will gradually replace the coaxial fiber.Microwave relay communications:Comparison of coaxial and easy to set up, low investment, short-cycle. Analog phone microwave communications mainly SSB / FM /FDM modulation, communication capacity of 6,000 road / Channel. Digital microwave using BPSK, QPSK and QAM modulation techniques. The use of 64QAM, 256QAM such as multi-level modulation technique enhance the capacity of microwave communications can be transmitted at 40M Channel 1920 ~ 7680 Telephone Rd PCM figure.Optical Fiber Communication: Optical fiber communication is the use of lasers in optical fiber transmission characteristics of long-distance with a large communication capacity, communication, long distance and strong anti-interference characteristics. Currently used for local, long distance, trunk transmission, and progressive development of fiber-optic communications network users. At present, based on the long-wave lasers and single-mode optical fiber, each fiber road approach more than 10,000 calls, optical fiber communication itself is very strong force. Over the past decades, optical fiber communication technology develops very quickly, and there is a variety of applications, access devices, photoelectric conversion equipment, transmission equipment, switching equipment, network equipment and so on. Fiber-optic communications equipment has photoelectric conversion module and digital signal processing unit is composed of two parts.Satellite communications: Distance communications, transmission capacity, coverage, and not subject to geographical constraints and high reliability. At present, the use of sophisticated techniques Analog modulation, frequency division multiplexing and frequency division multiple access. Digital satellite communication using digital modulation, time division multiple road in time division multiple access.Mobile Communications: GSM, CDMA. Number of key technologies for mobile communications: modulation techniques, error correction coding and digital voice encoding. Data Communication Systems.1.4 Five basic types of data communication system:（1）Off-line data transmission is simply the use of a telephone or similar link to transmit data without involving a computer system.The equipment used at both ends of such a link is not part of a computer, or at least does not immediately make the data available for computer process, that is, the data when sent and / or received are 'off-line'.This type of data communication is relatively cheap and simple.（2）Remote batch is the term used for the way in which data communication technology is used geographically to separate the input and / or output of data from the computer on which they are processed in batch mode.（3）On-line data collection is the method of using communications technology to provide input data to a computer as such input arises-the data are then stored in the computer (say on a magnetic disk) and processed either at predetermined intervals or as required.（4）Enquiry-response systems provide, as the term suggests, the facility for a user to extract information from a computer.The enquiry facility is passive, that is, does not modify the information stored.The interrogation may be simple, for example, 'RETRIEVE THE RECORD FOR EMPLOYEE NUMBER 1234 'or complex.Such systems may use terminals producing hard copy and / or visual displays.（5）Real-time systems are those in which information is made available to and processed by a computer system in a dynamic manner so that either the computer may cause action to be taken to influence events as they occur (for example as in a process control application) or human operators may be influenced by the accurate and up-to-date information stored in the computer, for example as in reservation systems.2 Signal spectrum with bandwidthElectromagnetic data signals are encoded, the signal to be included in the data transmission. Signal in time for the general argument to show the message (or data) as a parameter (amplitude, frequency or phase) as the dependent variable. Signal of their value since the time variables are or not continuous, can be divided into continuous signals and discrete signals; according to whether the values of the dependent variable continuous, can be divided into analog signals and digital Signal.Signals with time-domain and frequency domain performance of the two most basic forms and features. Time-domain signal over time to reflect changing circumstances. Frequency domain characteristics of signals not only contain the same information domain, and the spectrum of signal analysis, can also be a clear understanding of the distribution ofthe signal spectrum and share the bandwidth. In order to receive the signal transmission and receiving equipment on the request channel, Only know the time-domain characteristics of the signal is not enough, it is also necessary to know the distribution of the signal spectrum. Time-domain characteristics of signals to show the letter .It’s changes over time. Because most of the signal energy is concentrated in a relatively narrow band, so most of our energy focused on the signal that Paragraph referred to as the effective band Bandwidth, or bandwidth. Have any signal bandwidth. In general, the greater the bandwidth of the signal using this signal to send data Rate on the higher bandwidth requirements of transmission medium greater. We will introduce the following simple common signal and bandwidth of the spectrum.More or less the voice signal spectrum at 20 Hz ~ 2000 kHz range (below 20 Hz infrasound signals for higher than 2000 KHz. For the ultrasonic signal), but with a much narrower bandwidth of the voice can produce an acceptable return, and the standard voice-frequency signal gnal 0 ~ 4 MHz, so the bandwidth of 4 MHz.As a special example of the monostable pulse infinite bandwidth. As for the binary signal, the bandwidth depends on the generalThe exact shape of the signal waveform, as well as the order of 0,1. The greater the bandwidth of the signal, it more faithfully express the number of sequences.3 The cut-off frequency channel with bandwidthAccording to Fourier series we know that if a signal for all frequency components can be completely the same through the transmission channel to the receiving end, then at the receiving frequency components of these formed by stacking up the signal and send the signal side are exactly the same, That is fully recovered from the receiving end of the send-side signals. But on the real world, there is no channel to no wear and tear through all the Frequency components. If all the Fourier components are equivalent attenuation, then the signal reception while Receive termination at an amplitude up Attenuation, but the distortion did not happen. However, all the transmission channel and equipment for different frequency components of the degree of attenuation is differentSome frequency components almost no attenuation, and attenuation of some frequency components by anumber, that is to say, channel also has a certain amount of vibrationIncrease the frequency characteristics, resulting in output signal distortion. Usually are frequency of 0 Hz to fc-wide channel at Chuan harmonic lost during the attenuation does not occur (or are a very small attenuation constant), whereas in the fc frequency harmonics at all above the transmission cross Decay process a lot, we put the signal in the transmission channel of the amplitude attenuation of a component to the original 0.707(that is, the output signal Reduce by half the power) when the frequency of the corresponding channel known as the cut-off frequency (cut - off frequency).Cut-off frequency transmission medium reflects the inherent physical properties. Other cases, it is because people interested in Line filter is installed to limit the bandwidth used by each user. In some cases, because of the add channel Two-pass filter, which corresponds to two-channel cut-off frequency f1 and f2, they were called up under the cut-off frequency and the cut-off frequency.This difference between the two cut-off frequency f2-f1 is called the channel bandwidth. If the input signal bandwidth is less than the bandwidth of channel, then the entire input signal Frequency components can be adopted by the Department of channels, which the letter Road to be the output of the output waveform will be true yet. However, if the input signal bandwidth greater than the channel bandwidth, the signal of a Frequency components can not be more on the channel, so that the signal output will be sent with the sending end of the signal is somewhat different, that is produced Distortion. In order to ensure the accuracy of data transmission, we must limit the signal bandwidth.4 Data transfer rateChannel maximum data transfer rate Unit time to be able to transfer binary data transfer rate as the median. Improve data transfer rate means that the space occupied by each Reduce the time that the sequence of binary digital pulse will reduce the cycle time, of course, will also reduce the pulse width.The previous section we already know, even if the binary digital pulse signal through a limited bandwidth channel will also be the ideal generated wave Shape distortion, and when must the input signal bandwidth, the smaller channel bandwidth, output waveformdistortion will be greater. Another angle Degree that when a certain channel bandwidth, the greater the bandwidth of the input signal, the output signal the greater the distortion, so when the data transmissionRate to a certain degree (signal bandwidth increases to a certain extent), in the on-channel output signal from the receiver could not have been Distortion of the output signal sent to recover a number of sequences. That is to say, even for an ideal channel, the limited bandwidth limit System of channel data transfer rate.At early 1924, H. Nyquist (Nyquist) to recognize the basic limitations of this existence, and deduced that the noise-free Limited bandwidth channel maximum data transfer rate formula. In 1948, C. Shannon (Shannon) put into the work of Nyquist 1 Step-by-step expansion of the channel by the random noise interference. Here we do not add on to prove to those now seen as the result of a classic.Nyquist proved that any continuous signal f (t) through a noise-free bandwidth for channel B, its output signal as a Time bandwidth of B continuous signal g (t). If you want to output digital signal, it must be the rate of g (t) for interval Sample. 2B samples per second times faster than are meaningless, because the signal bandwidth B is higher than the high-frequency component other than a letter has been Road decay away. If g (t) by V of discrete levels, namely, the likely outcome of each sample for the V level of a discrete one, The biggest channel data rate Rm ax as follows:Rmax = 2Blog 2 V (bit / s)For example, a 3000 Hz noise bandwidth of the channel should not transmit rate of more than 6,000 bits / second binary digital signal.In front of us considered only the ideal noise-free channel. There is noise in the channel, the situation will rapidly deteriorate. Channel Thermal noise with signal power and noise power ratio to measure the signal power and noise power as the signal-to-noise ratio (S ignal - to -- Noise Ratio). If we express the signal power S, and N express the noise power, while signal to noise ratio should be expressed as S / N. However, people Usually do not use the absolute value of signal to noise ratio, but the use of 10 lo g1 0S / N to indicate the units are decibels (d B). For the S / N equal 10 Channel, said its signal to noise ratio for the 1 0 d B; the same token, if the channel S / N equal to one hundred, then the signal to noiseratio for the 2 0 d B; And so on. S hannon noise channel has about the maximum data rate of the conclusions are: The bandwidth for the BH z, signal to noise ratio for the S / N Channel, the maximum data rate Rm ax as follows:Rmax = Blog 2 (1 + S / N) (bits / second)For example, for a bandwidth of 3 kHz, signal to noise ratio of 30 dB for the channel, regardless of their use to quantify the number of levels, nor Fast sampling rate control, the data transfer rate can not be greater than 30,000 bits / second. S h a n n o n the conclusions are derived based on information theory Out for a very wide scope, in order to go beyond this conclusion, like you want to invent perpetual motion machine, as it is almost impossible.It is worth noting that, S hannon conclusions give only a theoretical limit, and in fact, we should be pretty near the limit Difficult.SUMMARYMessage signals are (or data) of a magnetic encoder, the signal contains the message to be transmitted. Signal according to the dependent variable Whether or not a row of values, can be classified into analog signals and digital signals, the corresponding communication can be divided into analog communication and digital communication.Fourier has proven: any signal (either analog or digital signal) are different types of harmonic frequencies Composed of any signal has a corresponding bandwidth. And any transmission channel signal attenuation signals will, therefore, Channel transmission of any signal at all, there is a data transfer rate limitations, and this is Chengkui N yquist (Nyquist) theorem and S hannon (Shannon) theorem tells us to conclusions.Transmission medium of computer networks and communication are the most basic part of it at the cost of the entire computer network in a very Large proportion. In order to improve the utilization of transmission medium, we can use multiplexing. Frequency division multiplexing technology has many Road multiplexing, wave division multiplexing and TDM three that they use on different occasions.Data exchange technologies such as circuit switching, packet switching and packetswitching three have their respective advantages and disadvantages. M odem are at Analog phone line for the computer's binary data transmission equipment. Modem AM modulation methods have, FM, phase modulation and quadrature amplitude modulation, and M odem also supports data compression and error control. The concept of data communications Data communication is based on "data" for business communications systems, data are pre-agreed with a good meaning of numbers, letters or symbols and their combinations.参考文献[1]C.Y.Huang and A.Polydoros,“Two small SNR classification rules for CPM,”inProc.IEEE Milcom,vol.3,San Diego,CA,USA,Oct.1992,pp.1236–1240.[2]“Envelope-based classification schemes for continuous-phase binary Frequency-shift-keyed modulations,”in Pr oc.IEEE Milcom,vol.3,Fort Monmouth,NJ,USA,Oct.1994,pp. 796–800.[3]A.E.El-Mahdy and N.M.Namazi,“Classification of multiple M-ary frequency-shift keying over a rayleigh fading channel,”IEEE m.,vol.50,no.6,pp.967–974,June 2002.[4]Consulative Committee for Space Data Systems(CCSDS),Radio Frequency and Modulation SDS,2001,no.401.[5]E.E.Azzouz and A.K.Nandi,“Procedure for automatic recognition of analogue and digital modulations,”IEE mun,vol.143,no.5,pp.259–266,Oct.1996.[6]A.Puengn im,T.Robert,N.Thomas,and J.Vidal,“Hidden Markov models for digital modulation classification in unknown ISI channels,”in Eusipco2007,Poznan,Poland, September 2007,pp.1882–1885.[7]E.Vassalo and M.Visintin,“Carrier phase synchronization for GMSK signals,”I nt.J.Satell. Commun.,vol.20,no.6,pp.391–415,Nov.2002.[8]J.G.Proakis,Digital Communications.Mc Graw Hill,2001.[9]L.Rabiner,“A tutorial on hidden Markov models and selected applications in speechrecognition,”Proc.IEEE,vol.77,no.2,pp.257–286,1989.英文译文：数据通信Gildas Avoine and Philippe OechslinEPFL, Lausanne, Switzerlandfgildas.avoine, philippe.oechsling@ep.ch摘要数据通信是通信技术和计算机技术相结合而产生的一种新的通信方式。
通信工程移动通信中英文对照外文翻译文献
中英文翻译附件1：外文资料翻译译文通用移动通信系统的回顾1.1 UMTS网络架构欧洲/日本的3G标准，被称为UMTS。
UMTS是一个在IMT-2000保护伞下的ITU-T 批准的许多标准之一。
随着美国的CDMA2000标准的发展，它是目前占主导地位的标准，特别是运营商将cdmaOne部署为他们的2G技术。
在写这本书时，日本是在3G 网络部署方面最先进的。
三名现任运营商已经实施了三个不同的技术：J - PHONE 使用UMTS，KDDI拥有CDMA2000网络，最大的运营商NTT DoCoMo正在使用品牌的FOMA（自由多媒体接入）系统。
FOMA是基于原来的UMTS协议，而且更加的协调和标准化。
UMTS标准被定义为一个通过通用分组无线系统（GPRS）和全球演进的增强数据技术（EDGE）从第二代GSM标准到UNTS的迁移，如图。
这是一个广泛应用的基本原理，因为自2003年4月起，全球有超过847万GSM用户，占全球的移动用户数字的68％。
重点是在保持尽可能多的GSM网络与新系统的操作。
我们现在在第三代（3G）的发展道路上，其中网络将支持所有类型的流量：语音，视频和数据，我们应该看到一个最终的爆炸在移动设备上的可用服务。
此驱动技术是IP协议。
现在，许多移动运营商在简称为2.5G的位置，伴随GPRS的部署，即将IP骨干网引入到移动核心网。
在下图中，图2显示了一个在GPRS网络中的关键部件的概述，以及它是如何适应现有的GSM基础设施。
SGSN和GGSN之间的接口被称为Gn接口和使用GPRS隧道协议（GTP的，稍后讨论）。
引进这种基础设施的首要原因是提供连接到外部分组网络如，Internet或企业Intranet。
这使IP协议作为SGSN和GGSN之间的运输工具应用到网络。
这使得数据服务，如移动设备上的电子邮件或浏览网页，用户被起诉基于数据流量，而不是时间连接基础上的数据量。
3G网络和服务交付的主要标准是通用移动通信系统，或UMTS。
通信工程外文资料翻译2篇
南京理工大学毕业设计(论文)外文资料翻译学院（系）：电子工程与光电技术学院专业：通信工程姓名：学号：外文出处：1. IEEE TRANSACTIONS ONANTENNAS AND PROPAGATION,VOL. 53,NO.9, SEPTEMBER 20052. IEEE TRANSACTIONS ONMICROWA VE THEORY ANDTECHNIQUES, VOL. 53,NO.6,JUNE 2005附件：1.外文资料翻译译文一；2.外文资料翻译译文二；3.外文原文一；4.外文原文二；注：请将该封面与附件装订成册。
附件1：外文资料翻译译文一在单封装超宽波段无线通信中使用LTCC技术的平面天线作者：Chen Ying and Y.P.Zhang摘要：此通讯提出了一个使用低温度共烧陶瓷技术的平面天线用于超宽频带（UWB）无线通信的单封装解决方案。
该天线具有一个通过微带线反馈的椭圆形的辐射体。
该辐射体和微带线拥有与其它UWBR电路相同的接地板。
实验结果表明原型天线已达到110.9％的带宽，从1.34到5.43 dBi的增益，宽模式和频率从3到10.6GHz 的相对恒定的群延迟。
更多地还发现，标准化天线辐射功率谱密度基本符合FCCS 对于室内UWB系统的发射限制。
关键词：低温共烧陶瓷（LTCC），平面天线，超宽频带（UWB）。
一、引言现在，发展用于窄范围高速度的无线通信网络的超宽频带（UWB）无线电是一个研究热点。
超宽带无线电利用一个7.5 GHz的超宽带宽来交换信息。
使用这样大的带宽，在使U超宽带无线电发挥它最大的作用上存在一些问题.其中的一个主要问题是用于移植系统的超宽带天线的设计。
好的超宽带天线应具有较低的回波损耗，全向辐射模式，从3.1至10.6 GHz的超宽带宽下的高效率，同时也应当满足FCCS规定的发射限制。
现在已经有一些超宽带天线，如钻石偶极子和互补缝隙天线。
它们已被证明适用于超宽带无线电[1] - [4]。
通信工程外文文献翻译
毕业设计（论文）的外文文献翻译原始资料的题目/来源：Fundamentals of wireless communications by David Tse翻译后的中文题目：无线通信基础专业通信工程学生王晓宇学号110240318班号1102403指导教师杨洪娟翻译日期2015年6月15日外文文献的中文翻译7．mimo：空间多路复用与信道建模本书我们已经看到多天线在无线通信中的几种不同应用。
在第3章中，多天线用于提供分集增益，增益无线链路的可靠性，并同时研究了接受分解和发射分解，而且，接受天线还能提供功率增益。
在第5章中，我们看到了如果发射机已知信道，那么多采用多幅发射天线通过发射波束成形还可以提供功率增益。
在第6章中，多副发射天线用于生产信道波动，满足机会通信技术的需要，改方案可以解释为机会波束成形，同时也能够提供功率增益。
章以及接下来的几章将研究一种利用多天线的新方法。
我们将会看到在合适的信道衰落条件下，同时采用多幅发射天线和多幅接收天线可以提供用于通信的额外的空间维数并产生自由度增益，利用这些额外的自由度可以将若干数据流在空间上多路复用至MIMO信道中，从而带来容量的增加：采用n副发射天线和接受天线的这类MIMO 信道的容量正比于n。
过去一度认为在基站采用多幅天线的多址接入系统允许若干个用户同时与基站通信，多幅天线可以实现不同用户信号的空间隔离。
20世纪90年代中期，研究人员发现采用多幅发射天线和接收天线的点对点信道也会出现类似的效应，即使当发射天线相距不远时也是如此。
只要散射环境足够丰富，使得接受天线能够将来自不同发射天线的信号分离开，该结论就成立。
我们已经了解到了机会通信技术如何利用信道衰落，本章还会看到信道衰落对通信有益的另一例子。
将机会通信与MIMO技术提供的性能增益的本质进行比较和对比是非常的有远见的。
机会通信技术主要提供功率增益，改功率增益在功率受限系统的低信噪比情况下相当明显，但在宽带受限系统的高信噪比情况下则很不明显。
通信工程 毕业设计 外文文献翻译：超宽带系统的数据通信
英文资料Ultra-Wideband Systems for Data CommunicationsG. Racherla, J.L. Ellis, D.S. Furuno, S.C. LinGeneral Atomics, Advanced Wireless Group10240 Flanders Ct. San Diego CA 92121WebsitABSTRACTUltra-Widebandt (UWB) is a radio transmission scheme that uses extremely low power pulses of radio energy spread across a wide spectrum of frequencies. UWB has several advantages over conventional continuous wave radio communications including potential support for high data rates, robustness to multipath interference and fading. We present an overview of UWB technology and its use in data communications and networking. We look at design considerations for UWB based networks at various layers of the protocol stack.1.INTRODUCTIONUltra-Wideband [1-6]一also known as baseband or impulse radio一is a carrier-free radio transmission that uses narrow, extremely low power pulses of radio energy spread across a wide spectrum of frequencies. UWB has recently gained a great deal of interest due to the recent Federal Communications Commission (FCC) Report and Order which allocates the UWB band一7.5 GHz of unlicensed spectrum for indoor and outdoor communication applications. UWB communications are required to have a -10 dB fractional bandwidth of more than 20% or a -10 dB bandwidth of more than 500 MHz [7]. It is important to note that the FCC has not defined a specific modulation scheme to be used. UWB systems offer the promise of high data rate, low susceptibilityto multipath fading, high transmission security low prime power requirements, low cost, and simple design [1,2,5,6].UWB has been used in military applications for the past several years for ground-penetrating precision radar applications and secure communications [3,8]. For the past few years, UWB has been developed for commercial applications [1,2,5,6]. With the recent FCC [7] report and order for theuse of UWB technology, there has been an added impetus to this endeavor. Other notable UWB applications include collision avoidance radar, tagging/identification; geolocation [9] and data communications in personal area networks (PAN) and local area network (LAN) environments.There are several future challenges to the wide adoption of UWB for wireless data communications including the infancy of the technology in the commercial arena, lack of reliablechannel models, the early stages of standardization effort and lack of low-cost system on chip (SoC) implementations. In this paper, we look at UWB technology for data communications and inside a UWB physical (PHY) layer characteristics. We also briefly introduce other related wireless standards such as 802.11 [10], 802.15.3 [11-13] Bluetooth [14], HomeRF [15] and HIPERLAN [16] and present a brief synopsis of the regulatory effort worldwide with special emphasis on the FCC. We also present the design considerations for UWB based data networking.2.ULTRA-WIDEBAND TECHNOLOGYThe basic waveform that employed in a UWB system is an approximation to an impulse, such as that shown in Fig. 1. The short duration of the pulse is associated with large inherent bandwidth; hence, the nomenclature "Ultra-Wideband". Typical attributes of UWB waveforms are summarized in Table 1.Fig. 1. UWB waveform example.The high spectral content of the UWB waveform gives rise to one of the primary advantages UWB operation for communications where a UWB system is robust against multipath fading[17] and narrowband interference [18]. In multipath fading, where the transmitted radio frequency (rt) signal can reflect off objects in its transmission path and can cause destructive interferences at the receiver, a loss of reception can occur. ThisTable 1: Characteristics of Typical UWB SystemsFractional Bandwidth > 20%Pulse Width 0.1-2 asPulse Repetition Frequency 1 kHz-2 GHzAverage Transmitted Power<1mWeffect is particularly problematic indoors where there are many reflecting surfaces. In the frequency domain, multipath is shown as frequency selective fading. Because UWB communications systems spreads the transmitted data over a broad frequency band if destructive interference occurs at a specific frequency, whether due to multipath or narrowband interference, the information can still be recovered over the good frequencies.UWB implementations can provide low complexity, low cost solutions [19], thus enabling vast deployments of the technology. A critical component that reaffirms a low cost solution is noting that UWB signals, being carrier-less, have greater simplicity over narrowband transceivers and require smaller silicon die sizes [20]. UWB can be designed to achieve very high bit rates while still achieving low power consumption, a feature set which will be exploited by the consumer electronics industry [21]. UWB schemes can further be designed to be very scalable in terms of complexity, bit rate, power consumption, and range.UWB technology can support many applications. Different UWB modulation schemes offer different advantages for communication, radar, and precisiongeo-location applications. UWB technology, which operates between 3.1 and 10.6 GHz, intrinsically offers an efficient reuse of precious spectrum by operating stealthily at the noise floor [22]. This UWB system operates at low power, to be compliant with operating under FCC Part 15 emissions, across a wide range of frequencies. As a spread spectrum technology, UWB offers a low probability of intercept and a low probability of detection [8]. Thus, it is particularly well suited for covert military or sensitive usage seenarios [8]. Because UWB signals have extremely short bursts in time (e.g., durations of 1 ns or less) they are suited for precision geo-location applications. Though UWB intrinsically offers the above-mentioned features, application optimization and improvements on these characteristics are left to specific designs and implementations, most notably by careful consideration of modulation schemes.2.1. UWB System Design ConsiderationsSeveral considerations are needed when designing a PAN. First, low power design is necessary because the portable devices within the network are battery powered. Second, high data rate transmission is crucial for broadcasting multiple digi\tal audio and video streams: Lastly, low cost is a prerequisite to broadening consumer adoption. In addition to these criteria, the UWB system designer must address synchronization and coexistence. Capturing and locking onto these short pulses make synchronization a non-trivial task. Coexisting peacefully with other wireless systems without interference is important;In particular, one needs to pay attention to the 802.1 la wireless LANs that operate in the 5 GHz ISM bands.At the physical layer, additional challenges lie in the transceiver and antenna design. At the transmitter, pulse shaping is required to produce flat and wideband emission in the desired frequency bands. Although new integrated circuits provide less expensive forms of integration, the pulses can be affected by the parasitics from the component and packaging [23]. To accommodate the high data rates, tradeoffs between high and low pulse repetition frequency (PRF) and modulation schemes must be considered. The low PRF system with higher modulation (more bits per symbol) may require a more complex receiver, while the high PRF system with lower modulation may lead to performance degradation for delay spread in the channel. Finally, traditional antenna designs gear towards narrow band systems. To avoid dispersion at the receiver, the new wideband antennas need phase linearity and a fixed phase center [23].3. UWB STANDARDIZATION ANDREGULATORY EFFORTSThere are several standards bodies presently considering, at some level, UWB technologies. The standards body most advanced in the consideration of UWB is study group "a" of IEEE 802.15.3, which was formed in November 2001 [11-13]. A serious effort is well underway to define a UWB channel model, and numerous UWB tutorials have been given. Many hallway conversations talk to a physical layer standard being ratified in 2004 (though there is no formal knowledge or position on this) and will accompany the soon to be approved 802.15.3 Medium Access Control (MAC) which supports quality of service (QoS) for real-time multimedia applications [12]. The technical requirements presently call for bit rates of 110 to 200 Mbps at ranges up to 10 m, with the option to achieve 480 Mbps possibly at shorter distances. The powerconsumption requirement is presently set at 100 to 250 mW with lOe 5 bit error rate at the top of the physical layer. Complexity/cost are presently expected to be comparable to Bluetooth and the physical layer is required to support four collocated piconets. Coexistence is presently crucial (e.g., IEEE 802.1 la) and the ability to scale the technology is key to a long lasting and widely adopted standard. These technical requirements come from documents that are still being revised; additionally, it is not possible to predict if proposals may fall short of meeting some of the desired requirements.The United States FCC issued a report and order in the early part of 2002. This landmark decision to permit UWB operation in the 3.1 to 10.6 GHz spectrum under Part 15 emis- sion limits, with some additional restrictions, has catalyzed development and standardization processes as is evident by the sheer number of entities (companies, academic and government institutions) associated with UWB and through the serious efforts of the IEEE 802.15.3 group. The FCC carefully chose the frequency band of operation to be above 3.1 GHz to avoid interfering with GPS and other life critical systems. Furthermore, the FCC ruled that emissions below Part 15 would pro-vide for peaceful coexistence, the ability to have narrowband and UWB systems collocated on a non-interfering basis, because unintentional emissions from devicessuch as laptops are also limited to Part 15 rules. This ruling makes it possible to have up to 15 UWB frequency bands in the 7.5 GHz allocated unlicensed spectrum [7]. Extensive efforts are being conducted throughout Europe (CEPT, ETSI, and the European Commission), Korea, and Japan (Association of Radio Industries and Businesses, and the Japanese Ministry of Telecommunications).4. NETWORKING WITH UWB SYSTEMSThere is a significant interest in the ability to perform location determination and tracking of assets and people throughout warehouses, factories, ships, hospita梦，business environments, and other buildings or structures. The ability for UWB technologies to operate within such intense multipath environments in conjunction with the ability for UWB to provide very accurate geo-location capability at low cost and long battery life justifies the increasing technological activity in this market [20].As the rf tags [24] are distributed, it is also recognized tha they can be coordinated and networked. To further reduce the cost of the transceivers, position determination can occur at networked computer terminals. Additionally, it is quite conceivable that tag complexity can be further simplified by installink transmitters that chirp periodically [8]. Just as UWB demonstrates many benefits for rf tags, the technology equally lends itself to distributed sensor networks [9]. Sensor network applications include feedback controls systems and environmental surveillance for commercial, industrial,_ and military applications.In the data communication area, UWB technology may be used to implement ad-hoc networks. An ad-hoc network [25-27] is characterized by a collection of hosts that form a network "on-the-fly". An ad-hoc network is a multi-hop wireless network wherein each host also acts as a router. Mobile TRANSPORT Ad-hoc NETworks (MANETs) [25-27] are ad-hoc networks wherein the wireless hosts have the ability to move. Mobility of hosts in MANETs has a profound impact on the topology of the network and its performance. Figure 2 illustrates how the various layers of the OSI protocol stack have to operate in order to successfully complete a communication session. We look at some of relevant design issues at the different layers for UWB-based sensor networks and MANETs.4.1. Design Issues for Layers of the Protocol StackThere are several design considerations of sensor networks setup (including rftags) [24]. The sensors typically work on batteries and need be low cost, low power, with LPI/LPD and the ability to do geo-location. All of these requirements are satisfied by a UWB PHY.The PHY layer [26,27] is a very complex layer which deals with the medium specification (physical, electrical and mechanical) for data transmission between devices. The PHY layer specifies the operating frequency range, the operating temperature range, modulation scheme, channelization scheme. channel switch time, timing, synchronization, symbol coding, and interference from other systems, carrier-sensing and transmit/receive operations of symbols and power requirements for operations. The PHY layer interacts closely with, the MAC sublayer to ensure smooth performance of the network. The PHY layer for wireless systems (such as MANETs) has special considerations to take into account as the wireless medium is inherently error-prone and prone to interference from other wireless and rf systems in the proximity. Multipath is important to consider when designing wireless PHY layer as the rf propagation environment changes dynamically with time; frequent disconnections may occur. The problem is exacerbated when the devices in the network are mobile because of handoffs and new route establishment. It should be noted that there is a concerted effort by several UWB companies muster supportfor a UWB-based high data rate PITY in the IEEE 802.15.3 working group.The data link layer consists of the Logical Link Control (LLC) and the MAC sub layers. The MAC sublayer is responsible for channel access and the LLC is responsible for link maintenance, framing data unit, synchronization, error detection and possible recovery, and flow control. The MAC sublayer tries to gain access to the shared channel to prevent collision and distortion of transmitted frames with frames sent by the MAC sublayers of other nodes sharing the medium. TheMAC sublayer in sensor networks and MANETs needs to be power-aware, self-organizing and support mobility and handoffs.The network layer of such networks should perform routing so as to minimize power and the number of node hops in the route. In some cases, flooding/gossiping may be required to increase chances of the packets reaching the destination. Data aggregation/fusion may be used for. data-centric routing [24] in the network layer. The network layer needs to allow for route maintenance and updates for fast changing network topology.The transport layer is responsible for the end-to-end integrity of data in thenetwork. The transport layer performs multiplexing, segmenting, blocking, concatenating, error detection and recovery, flow control and expedited data transfer. In the MANET environment, the mobility of the nodes will almost certainly cause packets to be delivered out of order and a significant delay in the acknowledgements is to be expected as a result. Retransmissions are very expensive in terms of the power requirements. Transport protocols for MANETs and sensor networks need to focus on the development of feedback mechanisms that enable the transport layer to recognize the dynamics of the network and adjust its retransmission timer, window size and perform congestion control with more information on the network.Fig. 2. Issues at each layer of the protocol stackThe application layer needs support for location-based services, network management, task assignment, query and data dissemination for sensor networks and possible MANETs.5. RELATED TECHNOLOGIESIn order to better understand UWB-based technologies, we look at some related technology standards. More information on these technologies can be found in Ref. 27.5.1. BluetoothBluetooth [14] is a short-range radio technology standard originallyintended as a wireless cable replacement to connect portable computers, wireless devices, handsets and headsets. Bluetooth devices operate in the 2.4 GHz ISM band. Bluetooth uses the concept of a piconet which is a MANET with a master device controlling one or several slave devices. Bluetooth also allow scatternets wherein a slave device can be part of multiple piconets. Bluetooth has beed designed to handle both voice and data. traffic.5.2. HIPERIANl1 and HIPERIANIlHIPERLAN/I and HIPERLAN/2 [16] are European wireless LAN (WLAN) standards developed by European Telecommunications Standards Institute (ETSI). HIPERLAN/1 is a wireless equivalent of Ethernet while HIPERLAN/2 has architecture based on wireless Asynchronous Transfer Mode (ATM). Both the standards use dedicated frequency spectrum at -5 GHz. HIPERLAN/I provides a gross data rate of 23.5 Mb/s and net data rate of more than 18 Mb/s while HIPERLAN/2 provides gross data rates of 6/16/36154 Mb/s and a maximum of 50 Mb/s net data rate. Both standards use 10/100/1000 mW of transmit power and have a maximum range of 50 m. Also, the standards provide isochronous and asynchronous services with support for QoS. However, they have different channel a-ss and modulation schemes.5.3. IEEE 802]]This IEEE family of wireless Etherdet standards is primarily intended for indoor and in-building WLANs. There are several varities of this standard. The current available versions are the 802.1 la, 802.11b and 802.llg (emerging draft standard) with other versions which are starting to show on the horizon [10]. The 802.11 standards support ad-hoc networking as well as connections using an access point (AP). The standard provides specifications of the PHY and the MAC layers. The MAC specified uses CSMA/CA for access and provides service discovery and scanning, link setup and tear down, data fragmentation, security, power management and roaming facilities. The 802.1 la PHY is similar to the HIPERLAN/2 PHY. The PHY uses OFDM and operates in the 5 GHz UNII band. 802.1 la supports data rates ranging from 6 to 54 Mbps. 802.11 a currently offers much less potential for rf interference than other PHYs (e.g., 802.11b and 802.11g) that utilize the crowded 2.4 GHz ISM band. 802.11 a can support multimedia applications in densely populated user environments.' The 802.11b standard, proposed jointly by Harris and Lucent Technologies, extends the 802.11 Direct Sequence Spread Spectrum (DSSS) PHY to provide 5.5 and 11 Mb/s data rates.5.4. IEEE 802.75.3The emerging draft standard [11-13] defines MAC and PHY (2.4 GHz) layer specifications for a Wireless Personal Area Network (WPAN). The standard is based on the concept of a piconet which is a network confined to a 10 m personal operating space (POS) around a person or object. A WPAN consists of one or more collocated piconets. Each piconet is controlled by a piconet coordinator (PNC) and may consist of devices (DEVs). The 802.15.3 PHY is defined for 2.4 to 2.4835 GHz band and has two defined channel plans. It supports five different data rates (11 to 55 Mb/s). The base uncoded PHY rate is 22 Mb/s5.5. HomeRFHomeRF [15] working group was formed to develop a standard for wireless data communication between personal computers and consumer electronics in a home environment. The HomeRF standard is technically solid, simple, secure, and is easy to use. HomeRF networks provide a range of up to 150 ft typically enough for home networking. HomeRF uses Shared Wireless Access Protocol (SWAP) to provide efficient delivery of voice and data traffic. SWAP uses a transmit power of up to 100 mW and a gross data rate of 2 Mb/s. It can support a maximum of 127 devices per network. A SWAP-based system can work as an ad-hoc network or as a managed network using a connection point6. CONCLUSIONIn this paper, we presented an overview of UWB technology and its characteristics and advantages over conventional, continuous wave transmissions. We presented how UWB is well suited for several applications like sensor networks and MANETs. UWB technology has garnered a lot of interest among vendors who are looking at standardizing the use of the technology in various forums including IEEE.中文翻译超宽带系统的数据通信G. Racherla, J.L. Ellis, D.S. Furuno, S.C. LinGeneral Atomics, Advanced Wireless Group10240 Flanders Ct.San Diego CA 92121E-mail: {gopal.racherla, jason.ellis, susan.lin,超宽带（UWB）是一种在宽频谱范围内使用超低功耗传播无线脉冲能量的无线电传输方案。
通信工程专业英语汉英对照
通信工程专业英语汉英对照(A-D)2008年11月14日 星期五 21:08A安全地线=safe ground wire安全特性 security feature安装线=hook-up wire按半周进行的多周期控制=multicycle controlled by half-cycle 按键电话机=push-button telephone set按需分配多地址=demand assignment multiple access(DAMA)按要求的电信业务=demand telecommunication service按组编码=encode by groupB八木天线=Yagi antenna白噪声=white Gaussian noise白噪声发生器=white noise generator半波偶极子=halfwave dipole半导体存储器=semiconductor memory半导体集成电路=semiconductor integrated circuit半双工操作=semi-duplex operation半字节=Nib包络负反馈=peak envelop negative feed-back包络延时失真=envelop delay distortion薄膜=thin film薄膜混合集成电路=thin film hybrid integrated circuit保护比（射频）=protection ratio (RF)保护时段=guard period保密通信=secure communication报头=header报文分组 packet报文优先等级=message priority报讯=alarm备用工作方式 spare mode背景躁声 background noise倍频 frequency multiplication倍频程 actave倍频程滤波器 octave filter被呼地址修改通知 called address modified notification 被呼用户优先 priority for called subscriber本地PLMN local PLMN本地交换机 local exchange本地移动用户身份 local mobile station identity ( LMSI)本地震荡器 local oscillator比功率(功率密度) specific power比特 bit比特并行 bit parallel比特号码 bit number (BN)比特流 bit stream比特率 bit rate比特误码率 bit error rate比特序列独立性 bit sequence independence必要带宽 necessary bandwidth闭环电压增益 closed loop voltage gain闭环控制 closed loop control闭路电压 closed circuit voltage边瓣抑制 side lobe suppression边带 sideband边带非线性串扰 sideband non-linear crosstalk边带线性串扰 sideband linear crosstalk边带抑制度 sideband suppression边角辐射 boundary radiation编号制度 numbering plan编解码器 codec编码 encode编码律 encoding law编码器 encoder编码器输出 encoder output编码器总工作时间 encoder overall operate time编码效率 coding efficiency编码信号 coded signal编码约束长度 encoding constraint length编码增益 coding gain编译程序 compiler鞭状天线 whip antenna变频器 converter变频损耗 converter conversion loss变容二极管 variable capacitance diode变形交替传号反转 modified alternate mark inversion便携电台 portable station便携设备 portable equipment便携式载体设备 portable vehicle equipment标称调整率（标称塞入率） nominal justification rate (nominal stuffing rate)标称值 nominal value标称呼通概率 nominal calling probability标准码实验信号 standard code test signal (SCTS)标准模拟天线 standard artificial antenna标准频率 standard frequency标准时间信号发射 standard-time-signal emission标准实验调制 standard test modulation标准输出功率 standard power output标准输入信号 standard input signal标准输入信号电平 standard input-signal level标准输入信号频率 standard input-signal frequency标准信躁比 standard signal to noise表面安装 surface mounting表示层 presentation layer并串变换器 parallel-serial converter (serializer)并馈垂直天线 shunt-fed vertical antenna并行传输 parallel transmission并行终端 parallel terminal拨号错误概率 dialing mistake probability拨号后延迟 post-dialing delay拨号交换机 dial exchange拨号线路 dial-up line拨号音 dialing tone拨号终端 dial-up terminal波动强度（在给定方向上的） cymomotive force (c. m. f)波段覆盖 wave coverage波峰焊 wave soldering波特 baud泊送过程 Poisson process补充业务 supplementary service (of GSM)补充业务登记 supplementary service registration补充业务询问 supplementary service interrogation补充业务互连 supplementary service interworking捕捉区（一个地面接收台） capture area (of a terrestrial receiving station)捕捉带 pull-in range捕捉带宽 pull-in banwidth捕捉时间 pull-in time不连续发送 discontinuous transmission (DTX)不连续干扰 discontinuous interference不连续接收 discontinuous reception (DRX)不确定度 uncertainty步谈机 portable mobile stationC采样定理 sampling theorem采样频率 sampling frequency采样周期 sampling period参考边带功率 reference side band power参考差错率 reference error ratio参考当量 reference equivalent参考点 reference point参考结构 reference configuration参考可用场强 reference usable fiend-strength参考灵敏度 reference sensibility参考频率 reference frequency参考时钟 reference clock参考输出功率 reference output power残余边带调制 vestigial sideband modulation残余边带发射 vestigial-sideband emission操作维护中心 operation maintenance center (OMC)操作系统 operation system (OS)侧音消耗 sidetone loss层2转发 layer 2 relay (L2R)插入组装 through hole pachnology插入损耗 insertion loss查号台 information desk差错控制编码 error control coding差错漏检率 residual error rate差分脉冲编码调制（差分脉码调制） differential pulse code modulation (DPCM)差分四相相移键控 differential quadrature phase keying (DQPSK)差分相移键控 differential phase keying (DPSK)差模电压，平衡电压 differential mode voltage, symmetrical voltage差拍干扰 beat jamming差频失真 difference frequency distortion长期抖动指示器 long-term flicker indicator长期频率稳定度 long-term frequency stability场强灵敏度 field intensity sensibility场效应晶体管 field effect transistor (FET)超长波通信 myriametric wave communication超地平对流层传播 transhorizon tropospheric超地平无线接力系统 transhorizon radio-relay system超高帧 hyperframe超帧 superframe超大规模集成电路 very-large scale integrated circuit (VLSI)超再生接收机 super-regenerator receiver车载电台 vehicle station撤消 withdrawal成对不等性码（交替码、交变码）paired-disparity code (alternative code, alternating code)承载业务 bearer service城市交通管制系统 urban traffic control system程序设计技术 programming technique程序设计环境 programming environment程序优化 program optimization程序指令 program command充电 charge充电率 charge rate充电效率 charge efficiency充电终止电压 end-of charge voltage抽样 sampling抽样率 sample rate初级分布线路 primary distribution link初始化 initialization处理增益 processing gain传播时延 propagation delay传播系数 propagation coefficient传导干扰 conducted interference传导杂散发射 conducted spurious emission传递函数 transfer function传递时间 transfer time传声器 microphone传输保密 transmission security传输层协议 transport layer protocol传输集群 transmission trunking传输结束字符 end of transmission character传输媒体 transmission medium传输损耗 transmission loss传输损耗 （无线线路的） transmission loss (of a radio link)传输通道 transmission path传输信道 transmission channel传真 facsimile, FAX船舶地球站 ship earth station船舶电台 ship station船舶移动业务 ship movement service船上通信电台 on-board communication station ,ship communication station船用收音机 ship radio串并变换机 serial to parallel (deserializer)串并行变换 serial-parallel conversion串话 crosstalk垂直方向性图 vertical directivity pattern唇式传声器 lip microphone磁屏蔽 magnetic shielding次级分布线路 secondary distribution link猝发差错 burst error猝发点火控制 burst firing control存储程序控制交换机 stored program controlled switching system D大规模集成电路 large scale integrated circuit (LSI)大信号信躁比 signal-to-noise ratio of strong signal带成功结果的常规操作 normal operation with successful outcome 带宽 bandwidth带内导频单边带 pilot tone-in-band single sideband带内谐波 in-band harmonic带内信令 in-band signalling带内躁声 in-band noise带通滤波器 band-pass filter带外发射 out-of-band emission带外功率 out-of-band power带外衰减 attenuation outside a channel带外信令 out-band signalling带状线 stripline单边带发射 single sideband (SSB) emission单边带发射机 single side-band (SSB) transmitter单边带调制 single side band modulation单边带解调 single side band demodulation单边带信号发生器 single side band signal generaltor单端同步 single-ended synchronization单工、双半工 simplex, halfduplex单工操作 simplex operation单工无线电话机 simplex radio telephone单呼 single call单频双工 single frequency duplex单频信令 single frequency signalling单相对称控制 symmetrical control (single phase)单相非对称控制 asymmetrical control (single phase)单向 one-way单向的 unidirectional单向控制 unidirectional control单信道地面和机载无线电分系统 SINCGARS单信道无绳电话机 single channel cordless telephone单信号方法 single-signal method单音 tone单音脉冲 tone pulse单音脉冲持续时间 tone pulse duration单音脉冲的单音频率 tone frequency of tone pulse单音脉冲上升时间 tone pulse rise time单音脉冲下降时间 tone pulse decay time单音制 individual tone system单元电缆段（中继段） elementary cable section (repeater section)单元再生段 elementary regenerator section (regenerator section)单元增音段，单元中继段 elementary repeater section当被呼移动用户不回答时的呼叫转移 call forwarding on no reply (CFNRy)当被呼移动用户忙时的呼叫转 calling forwarding on mobile subscriber busy (CFB)当漫游到原籍PLMN国家以外时禁止所有入呼 barring of incoming calls when roaming outside the home PLMN country (BIC-Roam)当前服务的基站 current serving BS当无线信道拥挤时的呼叫转移calling forward on mobile subscriber not reachable (CENRc)刀型天线 blade antenna导频 pilot frequency导频跌落pilot fall down倒L型天线 inverted-L antenna等步的 isochronous等幅电报 continuous wave telegraph等权网（互同步网） democratic network (mutually synchronized network)等效比特率 equivalent bit rate等效地球半径 equivalent earth radius等效二进制数 equivalent binary content等效全向辐射功率 equivalent isotropically radiated power (e.i. r. p.)等效卫星线路躁声温度 equivalent satellite link noise temperature低轨道卫星系统 LEO satellite mobile communication system低气压实验 low atmospheric pressure test低时延码激励线性预测编码 low delay CELP (LD-CELP)低通滤波器 low pass filter低温实验 low temperature test低躁声放大器 low noise amplifier地-空路径传播 earth-space path propagation地-空通信设备 ground/air communication equipment地波 ground wave地面连线用户 land line subscriber地面无线电通信 terrestrial radio communication地面站（电台） terrestrial station第N次谐波比 nth harmonic ratio第二代无绳电话系统 cordless telephone system second generation (CT-2)第三代移动通信系统 third generation mobile systems点波束天线 spot beam antenna点对地区通信 point-area communication点对点通信 point-point communication点至点的GSM PLMN连接 point to point GSM PLMN电报 telegraphy电报电码 telegraph code电波衰落 radio wave fading电池功率 power of battery电池能量 energy capacity of battery电池容量 battery capacity电池组 battery电磁波 electromagnetic wave电磁波反射 reflection of electromagnetic wave电磁波饶射 diffraction of electromagnetic wave电磁波散射 scattering of electromagnetic wave电磁波色射 dispersion of electromagnetic wave电磁波吸收 absorption of electromagnetic wave电磁波折射 refraction of electromagnetic wave电磁场 electromagnetic field电磁发射 electromagnetic field电磁辐射 electromagnetic emission电磁干扰 electromagnetic interference (EMI)电磁感应 electromagnetic induction电磁环境 electromagnetic environment电磁兼容性 electromagnetic compatibility (EMC)电磁兼容性电平 electromagnetic compatibility level 电磁兼容性余量 electromagnetic compatibility margin 电磁脉冲 electromagnetic pulse (EMP)电磁脉冲干扰 electromagnetic pulse jamming电磁敏感度 electromagnetic susceptibility电磁能 electromagnetic energy电磁耦合 electromagnetic coupling电磁屏蔽 electromagnetic shielding电磁屏蔽装置 electromagnetic screen电磁骚扰 electromagnetic disturbance电磁噪声 electromagnetic noise电磁污染 electromagnetic pollution电动势 electromotive force (e. m. f.)电话机 telephone set电话局容量 capacity of telephone exchange电话型电路 telephone-type circuit电话型信道 telephone-type channel电离层 ionosphere电离层波 ionosphere wave电离层传播 ionosphere propagation电离层反射 ionosphere reflection电离层反射传播 ionosphere reflection propagation电离层散射传播 ionosphere scatter propagation电离层折射 ionosphere refraction电离层吸收 ionosphere absorption电离层骚扰 ionosphere disturbance电流探头 current probe电路交换 circuit switching电屏蔽 electric shielding电视电话 video-telephone, viewphone, visual telephone 电台磁方位 magnetic bearing of station电台方位 bearing of station电台航向 heading of station电文编号 message numbering电文队列 message queue电文格式 message format电文交换 message switching电文交换网络 message switching network电文结束代码 end-of-message code电文路由选择 message routing电小天线 electronically small antenna电信管理网络 telecommunication management network (TMN)电信会议 teleconferencing电压变化 voltage change电压变化持续时间 duration of a voltage change电压变化的发生率 rate of occurrence of voltage changes电压变化时间间隔 voltage change interval电压波动 voltage fluctuation电压波动波形 voltage fluctuation waveform电压波动量 magnitude of a voltage fluctuation电压不平衡 voltage imbalance, voltage unbalance电压浪涌 voltage surge电压骤降 voltage dip电源 power supply电源电压调整率 line regulation电源抗扰性 mains immunity电源持续工作能力 continuous operation ability of the power supply电源去耦系数 mains decoupling factor电源骚扰 mains disturbance电子干扰 electronic jamming电子工业协会 Electronic Industries Association (EIA)电子系统工程 electronic system engineering电子自动调谐 electronic automatic tuning电子组装 electronic packaging电阻温度计 resistance thermometer跌落试验 fall down test顶部加载垂直天线 top-loaded vertical antenna定长编码 block code定期频率预报 periodical frequency forecast定时 clocking定时超前 timing advance定时电路 timing circuit定时恢复（定时抽取） timing recovery (timing extration)定时截尾试验 fixed time test定时信号 timing signal定数截尾试验 fixed failure number test定向天线 directional antenna定型试验 type test动态频率分配 dynamic frequency allocation动态信道分配 dynamic channel allocation动态重组 dynamic regrouping动态自动增益控制特性 dynamic AGC characteristic抖动 jitter独立边带 independent sideband独立故障 independent fault端到端业务 teleservice短波传播 short wave propagation短波通信 short wave communication短路保护 short-circuit protection短期抖动指示器 short-term flicker indicator短期频率稳定度 short-term frequency stability短时间中断（供电电压） short interruption (of supply voltage)段终端 section termination对称二元码 symmetrical binary code对地静止卫星 geostationary satellite对地静止卫星轨道 geostationary satellite orbit对地同步卫星 geosynchronous satellite对讲电话机 intercommunicating telephone set对空台 aeronautical station对流层 troposphere对流层波道 troposphere duct对流层传播 troposphere propagation对流层散射传播 troposphere scatter propagation多次调制 multiple modulation多点接入 multipoint access多电平正交调幅 multi-level quadrature amplitude modulation (QAM)多分转站网 multidrop network多服务器队列 multiserver queue多工 multiplexing多工器 nultiplexer多功能系统 MRS多级处理 multilevel processing多级互连网络 multistage interconnecting network多级卫星线路 multi-satellite link多径 multipath多径传播 multipath propagation多径传播函数 nultipath propagation function多径分集 multipath diversity多径时延 multipath delay多径衰落 multipath fading多径效应 multipath effect多路复接 multiplexing多路接入 multiple access多路信道 multiplexor channel多脉冲线性预测编码 multi-pulse LPC (MPLC)多频信令 multifrequency signalling多普勒频移 Doppler shift多跳路径 multihop path多信道选取 multichannel access (MCA)多信道自动拨号移动通信系统multiple-channel mobile communication system with automatic dialing多优先级 multiple priority levels多帧 multiframe多址呼叫 multiaddress call多址联接 multiple access多重时帧 multiple timeframe多用户信道 multi-user channel通信工程专业英语汉英对照(E-H)2008年11月14日 星期五 21:09E额定带宽 rated bandwidth额定射频输出功率 rated radio frequency output power额定使用范围 rated operating range额定音频输出功率 rated audio-frequency output power额定值 rated value爱尔兰 erlang恶意呼叫识别 malicious call identification (MCI)耳机（受话器） earphone耳机额定阻抗 rated impedance of earphone二十进制码 binary-coded decimal (BCD) code二十进制转换 binary-to-decimal conversion二十六进制转换 binary-to-hexadecimal conversion二进制码 binary code二进制频移键控 binary frequency shift keying (BFSK)二进制数 binary figure二频制位 binary digit(bit)二频制 two-frequency system二维奇偶验码 horizontal and vertical parity check code二线制 two-wire system二相差分相移键控 binary different phase shift keying (BDPSK)二相相移键控 binary phase shift keying (BPSK)F发报机 telegraph transmitter发射 emisssion发射（或信号）带宽 bandwidth of an emission (or a signal)发射机 transmitter发射机边带频谱 transmitter sideband spectrum发射机额定输出功率 rated output power of transmitter发射机合路器 transmitter combiner发射机冷却系统 cooling system of transmitter发射机启动时间 transmitter attack time发射机效率 transmitter frequency发射机杂散躁声 spurious transmitter noise发射机之间的互调 iner-transmitter intermodulation发射机对答允许频（相）偏transmitter maximum permissible frequency(phase) deviation 发射类别 class of emission发射频段 transmit frequency band发射余量 emission margin发送 sending发送响度评定值 send loudness rating (SLR)繁忙排队/自动回叫 busy queuing/ callback反馈控制系统 feedback control system反射功率 reflection power反射卫星 reflection satellite反向话音通道 reverse voice channel (RVC)反向控制信道 reverse control channel (RECC)泛欧数字无绳电话系统 digital European cordless telephone 方舱 shelter方向性系数 directivity of an antenna防爆电话机 explosion-proof telephone set防潮 moisture protection防腐蚀 corrosion protection防霉 mould proof仿真头 artificial head仿真耳 artificial ear仿真嘴 artificial mouth仿真天线 dummy antenna放大器 amplifier放大器线性动态范围 linear dynamic range of amplifier放电 discharge放电电压 discharge voltage放电深度 depth of discharge放电率 discharge rate放电特性曲线 discharge character curve非等步的 anisochronous非归零码 nonreturn to zero code (NRZ)非均匀编码 nonuniform encoding非均匀量化 nonuniform quantizing非连续干扰 discontinuous disturbance“非”门 NOT gate非强占优先规则 non-preemptive priority queuing discipline 非受控滑动 uncontrolled slip非线性电路 nonlinear circuit非线性失真 nonliear distortion非线性数字调制 nonlinear digital modulation非占空呼叫建立 off-air-call-set-up (OACSU)非专用控制信道 non-dedicated control channel非阻塞互连网络 non-blocking interconnection network分贝 decibel (dB)分辨力 resolution分布参数网络 distributed parameter network分布式功能 distributed function分布式数据库 distributed database分别于是微波通信系统 distributed microwave communication system分布式移动通信系统 distributed mobile communication system 分布路线 distribution link分段加载天线 sectional loaded antenna分机 extension分集 diversity分集改善系数 diversity improvement factor分集间隔 diversity separation分集增益 diversity gain分集接收 diversity reception分接器 demultiplexer分频 frequency division分散定位 distributed channel assignment分散控制方式 decentralized control分散式帧定位信号 distributed frame alignment signal分同步（超同步）卫星 sub-synchronous (super-synchronous) satellite分谐波 subharmonic分组交换 packet switching分组码 block code分组无线网 packet radio network分组循环分散定位 block cyclic distributed channel assigment 分组组装与拆卸 packet assembly and disassembly封闭用户群 closed user group (CUG)峰包功率 peak envelop power峰值 peak value峰值-波纹系数 peak-ripple factor峰值包络检波 peak envelop detection峰值功率 peak power峰值功率等级（移动台的） peak power class (of MS)峰值检波器 peak detector峰值限制 peak limiting蜂窝手持机 cellular handset蜂窝系统 cellular system缝隙天线 slot antenna服务基站 serving BS服务访问点 service access point (SAP)服务弧 service arc服务可保持性 service retainability服务可得到性 service accessibility服务提供部门 service provider服务完善性 service integrity服务小区 serving cell服务易行性 service operability服务支持性 service supportability服务质量 quality of service服务准备时间 service provisioning time符号率 symbol rate幅度检波 amplitude detection幅度量化控制 amplitude quantized cntrol幅度失真 amplitude distortion幅度调制 amplitude modulation (AM)幅频响应 amplitude-frequency response幅相键控 amplitude phase keying (APK)辐射 radiation辐射单元 radiating element辐射方向图 radiation pattern辐射干扰 radiated interference辐射近场区 radiating near-field region辐射能 radiant energy辐射强度 radiation intensity辐射区 radiated area辐射实验场地 radiation test site辐射效率 radiation efficiency辐射源（电磁干扰） emitter (of electromagnetic disturbance)辐射杂散发射 radiated spurious emission辐射阻抗 radiation impedance俯仰角 pitch angle负极 negative electrode负离子 negative ion负荷容量（过荷点） load capacity (overload point)负逻辑 negative logic负码速调整（负脉冲塞入） negative justification (negative pulse stuffing)负载调整率 load regulation负阻放大器 negative resistance amplifier负阻效应 negative resistance effect负阻振荡 negative resistance oscillation附加符号 additional character附加位 overhead bit复合音 complex sound复接器 multiplexer复节-分接器 muldex复接制 multiple connection system复位 reset复用转接器 transmultiplexer复帧 multiframe副瓣 minor lobe副瓣电平 minor level覆盖区（一个地面发射台的） coverage area (of a terrestrial transmitting station)G概率 probability概率分布 probability distribution概率信息 probabilistic information概率译码 probabilistic decoding干扰 interference干扰参数 interference parameter干扰限值 limit of interference干扰信号 interfering signal干扰抑制 interfering suppression干扰源 interfering resource干线 trunk line感应近场区 reactive near-field region港口操作业务 port operation service港口电台 port station港口管理系统 harbor management system港口交通管理系统 harbor traffic control system高[低]电平输出电流 high (low)-level output current高[低]电平输出电压 high (low)-level output voltage高波 high-angle ray高层功能 high layer function高层协议 high layer protocol高级数据链路控制规程 high level data link control (HDLC) procedure高级通信业务 advanced communication service高级研究计划署 Advanced Research Projects Agency (ARPA)高级移动电话系统 Advanced Mobile Phone System (AMPS)高频放大器 high frequency amplifier高频提升 high frequency boost高频增益控制 high frequency gain control高斯信道 Gauss channel (AWG)高斯最小频移键控 Guassian minimum shift keying (GMSK)高频制频率时的发射频偏 transmitting frequency deviation of high frequency高通滤波器 highpass filter高温高湿偏置试验 high temperature high humidity biased testing (HHBT)高温功率老化 burning高温试验 high temperature test告警接收机 warning receiver告警指示信号 alarm indication signal (AIS)戈莱码 Golay code戈帕码 Goppa codes格码调制 trellis codes modulation schemes (TCM)隔离放大器 isolation amplifier个人数字助理 personal digital assistant (PDA)个人电台 personal station (PS)个人电台系统 personal radio system个人识别号码 personal identification number (PIN)个人通信 personal communications个人通信网 personal communication networks (PCN)个人携带电话 personal handy phone (PHP)个人移动性 personal mobility个体接收（在卫星广播业务中） individual reception 跟踪保持电路 track and hold circuit跟踪带宽 tracking bandwidth更改地址插入 changed address interception工科医用（的） ISM工科医用频段 ISM frequency band工业干扰 industrial interference工作最高可用频率 operational MUF工作比 duty cycle工作范围 working range工作频率范围 operating frequency range工作站 work station (WS)工作周期 cycle of operation公共分组交换网 public packet switched network公共耦合点 point of common coupling (PCC)公开密匙体制 public key system公路交通管制系统 highway traffic control system公用数据网 public data network公众陆地移动电话网 public land mobile network (PLMN)功能键 function key功能群，功能群令 function group, function grouping 功率合成 power synthesis功能控制报文 power control message功率控制电平 power control level功率谱密度 power spectrum density功率损耗 power loss功率因子 power factor供电系统阻抗 supply system impedance共道抑制 co-channel suppression共道信令 co-channel signalling共模电压，不平衡电压 common mode voltage, asymmetrical voltage 共模电流 common mode current共模转换 common code conversion共模干扰 common code interference共模抑制比 common code rejection ratio (CMRR)共模增益 common mode gain共模阻抗 common code impedance共信道再用距离 co-channel re-use distance贡献路线 contribution link固定电台 fixed station固定基地电台 fixed base station固定信道指配 fixed channel assignment固态发射机 solidstate transmitter固有可靠性 inherent reliability固有频差 inherent frequency error故障 fault故障安全 fault safe故障保护 fault protection故障弱化 failsoft故障修复 fault correcting故障原因 fault cause故障准则 fault criteria挂机信号 hang-up signal管理中心 administration center (ADC)广播控制信道（BCCH）划分 BCCH allocation (BA)广播寻呼系统 broadcast paging system广域网 wide area network (WAN)归零码 return to zero code (RZ)归一化的偏置 normalized offset规程 protocol规范 specification规则脉冲激励编码 regular-pulse excitation (RPE)规则脉冲激励长时预测编码 regular-pulse excitation LPC (RPE-LPC)轨道 orbit国际标准 international standard国际单位制 international system of units国际电报电话咨询委员会 CCITT国际电工委员会 IEC国际电信联盟 ITU国际互连网 Internet国际民航组织 ICAO , international civil aviation organization 国际通信卫星组织 INTERAT国际海事卫星组织 INMAR-SAT国际无线电干扰特别委员会 CISPR国际无线电干扰委员会 CCIR国际移动识别码 international mobile station equipment identity (IMEI)国际移动用户识别码 international mobile subscriber identity(IMSI)国际原子时间 international automatic time (TAI)国家标准 national standard国家信息基础结构 national information infrastructure (NII)过充电 overcharge过滤带 transition band过放电 overdischarge过荷保护电路 overload protecting circuit过荷分级控制 overload control category过荷控制 overload control过调制 overmodulation过流保护 overcurrent protection过压保护 overvoltage protectionH海岸地球站 coast earth station海岸电台 coast station海事卫星通信 maritime satellite communications汉明距离 Hamming distance汉明码 Hamming code汉明重量 Hamming weight航空地球站 aeronautical earth station航空电台 aeronautical station航空器地球站 aircraft earth station航空器电台 aircraft station航空移动业务 aeronautical mobile service航天器（宇宙飞船） spacecraft毫米波 millimeter wave黑格巴哥码 Hagelbarger code恒比码 constant ratio code恒步的 homochronous恒流电源 constant current power supply恒温恒湿试验 constant temperature and humid test恒压充电 constant voltage charge恒压电源 constant voltage power supply恒电磁波小室 transverse electromagnetic wave cell (TEM cell)喉式传声器 throat microphone后瓣 back hole厚模电路 thick-film circuit呼叫 call呼叫支持 call hold (HOLD)呼叫存储 call store呼叫等待 call waiting (CW)呼叫改发 call redirection呼叫建立 call establishment呼叫建立时间 call set-up time呼叫接通率 percept of call completed呼叫控制信号 call control signal呼叫清除延时 call clearing delay呼叫释放 call release呼叫序列 calling sequence呼叫转移 call transfer (CT)呼救 distress call呼救系统 distress system呼损率 percept of call lost呼通概率 calling probability互补金属氧化物半导体集成电路complementary MOS integrated circuit (COMOS-IC)互连 interworking互连的考虑 interworking consideration互连功能 interworking function (IWF)互调 intermodulation互调产物（一个发射台的） intermodulation products (of a transmitting stastion)互调抗扰性 intermodulation immunity互调失真 intermodulation distortion互通性 interoperability互同步网 mutually synchronized network话路输入电平 voice circuit input level话路输入电平差异 voice circuit input level difference话务量 telephone traffic话音活动检测 voice activity detection (VAD)话音激活 voice exciting话音激活率 speech activity话音数字信令 speech digit signalling话音突发 speech spurt环境试验 environment test环境系数 environment factor环境应力筛选 environment stress screening (ESS)环境躁声 ambient noise环路传输 loop transmission环路高频总增益 loop RF overall gain环路可锁定最底（最高）界限角频率loop lockable minimum (maximum) margin angular frequency 环路滤波器比例系数 loop filter proportion coefficient环路躁声带宽 loop noise bandwidth环路增益 loop gain环路直流总增益 loop DC overall gain环路自然谐振角频率 loop natural resonant angular frequency 环形波 ring wave环形混频器 ring mixer环行器 circulator环行延迟 rounding relay恢复 recovery恢复规程 restoration procedure汇接交换 tandem switching汇接局 tandem office会话（在电信中） conversation (in telecommunication)会话层 session layer会议电话 conference telephone混合ARQ hybrid ARQ混合差错控制 hybrid error control (HEC)混合分集 hybrid diversity混合集成电路 hybrid integrated circuit混合扩频 hybrid spread spectrum混合路径传播 mixed-path propagation混合信道指配 hybrid channel assignment混频器 mixer混频器的寄生响应 mixer spurious response活动模式 active mode“或”门 OR gate“或非”门 NOR gate通信工程专业英语汉英对照(I-L)2008年11月14日 星期五 21:11J机壳辐射 cabinet radiation机载电台 aircraft station基本传输损耗（无线线路的） basic transmission loss (of a radio link)基本接入 basic access基本业务（GSM的） basic service (of GSM)基本越区切换规程 basic handover procedure基本最高可用频率 basic maximun usable frequency基波（分量） fundamental (component)基波系数 fundamental factor基带 baseband基地（海岸）（航空）设备 base (coast)(aeronautical) equipment 基地电台 base station (BS)基站控制器 base station controller (BSC)基站识别码 base station identity code (BSIC)基站收发信台 base transceiver station (BTS)基站系统 base station system (BSS)基站区 base station area基准条件 reference condition基准阻抗 reference impedance奇偶校验码 parity check code奇偶校验位 parity bit激活 activation吉尔伯特码 Gilbert code级联码 concatenated code即时业务 demand service急充电 boost charge急剧衰落 flutter fading集成电路 integrated circuit集成电路卡 integrated circuit card集群电话互连 trunked telephone connect集群电话互连器 trunked telephone connector集群基站 trunked base station集群效率 trunking efficiency集群移动电话系统 trunked mobile communication system集体呼叫 group call集体接收（在卫星广播业务中） community reception集中控制方式 centralized control集中式帧定位信号 bunched frame alignment signal计费信息 advice of charge计算机病毒 computer virus计算机辅助测试 computer-aided test (CAT)计算机辅助工程 computer-aided engineering (CAE)计算机辅助管理 computer-aided management (CAM)计算机辅助教学 computer-aided instruction (CAU)计算机辅助设计 computer-sided design (CAD)寄生反馈 parasitic feedback寄生调制 parasitic modulation寄生振荡 parasitic oscillation加密 encipherment加密保护 encipherment protection加密方案 encipherment scheme加权（互同步）网 hierarchic (mutually synchrohous) network。
通信工程毕业设计的论文外文翻译TDCDM与WCM络优化分析
毕业设计（论文）外文参考资料及译文译文题目: TD-SCDMA与WCMA网络优化分析3G network optimization 学生姓名：学号：专业：通信工程所在学院:龙蟠学院指导教师：职称：讲师2011年 12 月 1 日说明:要求学生结合毕业设计（论文）课题参阅一篇以上的外文资料，并翻译至少一万印刷符（或译出3千汉字）以上的译文。
译文原则上要求打印(如手写，一律用400字方格稿纸书写），连同学校提供的统一封面及英文原文装订,于毕业设计（论文）工作开始后2周内完成，作为成绩考核的一部分.3G network optimization摘自TD-SCDMA无线网络优化原理及方法One, the basic process of 3G network optimizationOperators aim is to build a profitable network, they are very concerned about the network construction, expansion and upgrade in the process of investment cost and its final performance, but the expansion，upgrade costs and network performance is a pair of contradiction. Construction cost budget and control can get relatively accurate numerical，but the performance of the network is composed of many subjective and objective factors. On one hand, the network capacity expansion，upgrading and upgrades to existing users can guarantee the normal use，on the other hand, it also can provide competitive new business，and makes further expansion，upgrading and upgrades can be carried out smoothly。
通信工程移动通信中英文对照外文翻译文献
中英文翻译(文档含英文原文和中文翻译)附件1：外文资料翻译译文通用移动通信系统的回顾1.1 UMTS网络架构欧洲/日本的3G标准，被称为UMTS。
UMTS是一个在IMT-2000保护伞下的ITU-T 批准的许多标准之一。
随着美国的CDMA2000标准的发展，它是目前占主导地位的标准，特别是运营商将cdmaOne部署为他们的2G技术。
在写这本书时，日本是在3G 网络部署方面最先进的。
三名现任运营商已经实施了三个不同的技术：J - PHONE 使用UMTS，KDDI拥有CDMA2000网络，最大的运营商NTT DoCoMo正在使用品牌的FOMA（自由多媒体接入）系统。
FOMA是基于原来的UMTS协议，而且更加的协调和标准化。
UMTS标准被定义为一个通过通用分组无线系统（GPRS）和全球演进的增强数据技术（EDGE）从第二代GSM标准到UNTS的迁移，如图。
这是一个广泛应用的基本原理，因为自2003年4月起，全球有超过847万GSM用户，占全球的移动用户数字的68％。
重点是在保持尽可能多的GSM网络与新系统的操作。
我们现在在第三代（3G）的发展道路上，其中网络将支持所有类型的流量：语音，视频和数据，我们应该看到一个最终的爆炸在移动设备上的可用服务。
此驱动技术是IP协议。
现在，许多移动运营商在简称为2.5G的位置，伴随GPRS的部署，即将IP骨干网引入到移动核心网。
在下图中，图2显示了一个在GPRS网络中的关键部件的概述，以及它是如何适应现有的GSM基础设施。
SGSN和GGSN之间的接口被称为Gn接口和使用GPRS隧道协议（GTP的，稍后讨论）。
引进这种基础设施的首要原因是提供连接到外部分组网络如，Internet或企业Intranet。
这使IP协议作为SGSN和GGSN之间的运输工具应用到网络。
这使得数据服务，如移动设备上的电子邮件或浏览网页，用户被起诉基于数据流量，而不是时间连接基础上的数据量。
通信工程专业英语论文翻译
CDMA versus TDMATerm Paper :DTEC 6810Submitted by:Sabareeshwar Natarajan.Fall 2006DTEC 6810Communication TechnologyCDMA Vs TDMA in travel:Both GSM and CDMA can be found across United States, which doesn’t mean that it doesn’t matter which technology we choose. When we travel domestically it is possible that we reach areas where digital service is not available. While traveling between places it is possible that we reach certain rural areas were only analog access is offered. CDMA handsets offer analog capabilities which the GSM don’t offer. Another difference between GSM and CDMA is in the data transfer methods. GSM’s high-speed wireless data technology, GPRS (General Packet Radio Service), usually offers a slower data bandwidth for wireless data connection than CDMA’s high-speed technology, which has the capability of providing ISDN (Integrated Services Digital Network) with speeds as much as 144Kbps.GSM’s benefits over the CDMA in domestic purpose are that GSM uses SIM card that identifies a user and stores the information in the handset. The SIM card can be swapped between handsets, which enable to move all the contacts to the new handset with ease. CDMA can have this flexibility with their own service that stores data on the operator’s datab ase. This service allows the user to swap data’s between two handsets with a little trouble, but the advantage is it can be done when the handset is even lost but in GSM technology, when a handset is lost, SIM card is also lost with it.When it comes for international roaming handsets with GSM is far better than CDMA handsets because GSM is used in most the markets across the globe. Users using tri-band or quad-band can travel to Europe, India and most of Asia and still can use their cell phone. CDMA does not have this multiband capability, thus cannot be used multiple countries with ease.Differences between CDMA and TDMA:CDMA technology claims that its bandwidth is thirteen times efficient than TDMA and forty times efficient than analog systems. CDMA also have better security and higher data and voice transmission quality because of the spread spectrum technology it uses, which has increased resistance to multipath distortion. The battery life is higher in TDMA compared to CDMA because CDMA handsets transmit data all the time and TDMA does not require constant transmission. CDMA has greater coverage area when compared to TDMA. Though, when it comes to international roaming TDMA is better than CDMA. CDMA is patented by Qualcomm, so an extra fee is paid to Qualcomm. When it comes to United States and Canada market size for CDMA is larger than GSM’s market size but worldwide the market size for GSM is far bigger both in the number of subscribers and coverage ,than CDMA.Conclusion:From the comparisons made above we cannot say that TDMA is better than CDMA or vice versa. The main advantage of the CDMA is that, in the single detection method it is more flexible than TDMA or joint detection. CDMA is said to have higher capacity than TDMA. But in the future GSM can be extended by an optional CDMA component in order to further increase the capacity. Finally, it does not matter whether which one is better CDMA or TDMA right now. It can be only found out with the evolution of these technologies. When going for a cell phone the user should choose the technology according to where they use it. For users who travel abroad it is better to go with GSM handsets. For the users in United States CDMA is better than TDMA because of the coverage we can get at rural areas where digital signals cannot be transmitted.CDMA与TDMA学期论文：6810 DTEC提交：sabareeshwar纳塔拉詹。
现代移动通信 毕业论文外文翻译 (2)
一、英文原文Modern mobile communication technologyIn now highly the information society, the information and the correspondence have become the modern society “the life”. The information exchange mainly relies on the computer correspondence, but corresponds takes the transmission method, with the sensing technology, the computer technology fuses mutually, has become in the 21st century the international society and the world economic development powerful engine. In order to of adapt the time request, the new generation of mobile communication technology seasonable and lives, the new generation of mobile communication technology is the people said that third generation's core characteristic is the wide band addressing turns on non-gap roaming between the rigid network and numerous different communications system's, gains the multimedia communication services.Along with the time progress, the technical innovation, people's life request's enhancement, the mobile communication technology renewal speed is quite astonishing, almost every other ten year mobile communication technology has a transformation update, from the 1980s “the mobile phone” to present's 3G handset, during has had two mobile communication technology transformation, transits from 1G AMPS to 2G GSM, from GSM to IMT-2000 (i.e. 3G technology). Knows modern on me the mobile communication technology to have the following several aspect important technology:1. wideband modulation and multiple access techniqueThe wireless high speed data transmission cannot only depend on the frequency spectrum constantly the expansion, should be higher than the present number magnitude at least in the frequency spectrum efficiency, may use three technologies in the physical level, namely OFDM, UWB and free time modulation code. OFDM with other encoding method's union, nimbly OFDM and TDMA, FDMA, CDMA, SDMA combines the multiple access technique.In the 1960s the OFDM multi-channel data transmission has succeeded uses in complex and the Kathryn high frequency military channels. OFDM has used in 1.6 M bit/s high bit rate digital subscriber line (HDSL), 6 M bit/s asymmetrical digital subscriber line (ADSL), 100 M bit/s really high speed figure subscriber's line (VDSL), digital audio frequency broadcast and digital video broadcast and so on. OFDM applies on 5 GHz provides 54 M bit/s wireless local network IEEE 802.11 a and IEEE 802.11g, high performance this region network Hi per LAN/2 and ETSI-BRAN, but also takes metropolitan area network IEEE 802.16 and the integrated service digit broadcast (ISDB-T) the standard. Compares with the single load frequency modulation system service pattern, the OFDM modulation service pattern needs to solve the relatively big peak even power ratio (PAPR, Peak to Average Power Ratio) and to the frequency shifting and the phase noise sensitive question.High speed mobile communication's another request is under the wide noise bandwidth, must demodulate the signal-to-noise ratio to reduce as far as possible, thus increases the cover area. May adopt the anti-fading the full start power control and the pilot frequency auxiliary fast track demodulation technology, like the frequency range anti-fading's Rake receive and the track technology, the OFDMA technology which declines from the time domain and the frequencyrange resistance time and the frequency selectivity, the link auto-adapted technology, the union coding technique.2. frequency spectrum use factor lift techniqueThe fundamental research pointed out: In the independent Rayleigh scattering channel, the data rate and the antenna several tenth linear relationships, the capacity may reach Shannon 90%. Is launching and the receiving end may obtain the capacity and the frequency spectrum efficiency gain by the multi-antenna development channel space. The MIMO technology mainly includes the spatial multiplying and the space diversity technology, concurrent or the salvo same information enhances the transmission reliability on the independent channel.Receives and dispatches the bilateral space diversity is the high-capacity wireless communication system uses one of technical. Bell Lab free time's opposite angle BLAST (D-BLAST) capacity increase to receive and dispatch the bilateral smallest antenna number in administrative levels the function. The cross time domain which and the air zone expansion signal constitutes using MIMO may also resist the multi-diameter disturbance. V-BLAST system when indoor 24~34 dB, the frequency spectrum use factor is 20~40 bit/s/Hz. But launches and the receiving end uses 16 antennas, when 30 dB, the frequency spectrum use factor increases to 60~70 bit/s/Hz.The smart antenna automatic tracking needs the signal and the auto-adapted free time processing algorithm, produces the dimensional orientation wave beam using the antenna array, causes the main wave beam alignment subscriber signal direction of arrival through the digital signal processing technology, the side lobe or zero falls the alignment unwanted signal direction of arrival. The auto-adapted array antennas (AAA, Adaptive Array Antennas) disturbs the counter-balance balancer (ICE, Interference Canceling Equalizer) to be possible to reduce disturbs and cuts the emissive power.3. software radio technologyThe software radio technology is in the hardware platform through the software edition by a terminal implementation different system in many kinds of communication services. It uses the digital signal processing language description telecommunication part, downloads the digital signal processing hardware by the software routine (DSPH, Digital Signal Processing Hardware). By has the general opening wireless structure (OWA, Open Wireless Architecture), compatible many kinds of patterns between many kinds of technical standards seamless cut.UWB is also called the pulse to be radio, the modulation uses the pulse width in the nanosecond level fast rise and the drop pulse, the pulse cover frequency spectrum from the current to the lucky hertz, does not need in the radio frequency which the convention narrow band frequency modulation needs to transform, after pulse formation, may deliver directly to the antenna launch.4. software radio technologyThe software radio technology is in the hardware platform through the software edition by a terminal implementation different system in many kinds of communication services. It uses the digital signal processing language description telecommunication part, downloads the digital signal processing hardware by the software routine (DSPH, Digital Signal Processing Hardware). By has the general opening wireless structure (OWA, Open Wireless Architecture), compatible many kinds of patterns between many kinds of technical standards seamless cut.5. network security and QoSQoS divides into wireless and the wired side two parts, wireless side's QoS involves theradio resource management and the dispatch, the admission control and the mobility management and so on, the mobility management mainly includes the terminal mobility, individual mobility and service mobility. Wired side's QoS involves based on the IP differ discrimination service and the RSVP end-to-end resources reservation mechanism. Mechanism maps the wireless side IP differ IP the QoS. Network security including network turning on security, core network security, application security, safety mechanism visibility and configurable.In the above modern mobile communication key technologies' foundation, has had the land honeycomb mobile communication, the satellite communication as well as the wireless Internet communication, these mailing address caused the correspondence appearance to have the huge change, used the digital technique the modern wireless communication already to permeate the national economy each domain and people's daily life, for this reason, we needed to care that its trend of development, hoped it developed toward more and more convenient people's life's direction, will let now us have a look at the modern mobile communication the future trend of development.modern mobile communication technological development seven new tendencies :First, mobility management already from terminal management to individual management and intelligent management developmentSecond, network already from synchronized digital circuit to asynchronous digital grouping and asynchronous transfer mode (ATM) development;the three, software's developments actuated from the algorithm to the procedure-oriented and face the goal tendency development;the four, information processing have developed from the voice to the data and the image;five, wireless frequency spectrum processing already from narrow band simulation to the narrow band CDMA development;the six, computers have developed from central processing to the distributional server and intellectualized processing;the seven, semiconductor devices have developed from each chip 16,000,000,000,000 /150MHz speed VLSI to 0.5 /350MHz speed VLSI and 2,000,000,000,000,000 /550MHz speed VLSI.Under this tendency's guidance, the mobile service rapid development, it satisfied the people in any time, any place to carry on the correspondence with any individual the desire. The mobile communication realizes in the future the ideal person-to-person communication service way that must be taken. In the information support technology, the market competition and under the demand combined action, the mobile communication technology's development is progresses by leaps and bounds, presents the following several general trends: work service digitization, grouping; 2. networking wide band; working intellectualization; 4.higher frequency band; 5. more effective use frequency; 6.each kind of network tends the fusion. The understanding, grasps these tendencies has the vital practical significance to the mobile communication operator and the equipment manufacturer.二、英文翻译现代移动通信在当今高度信息化的社会，信息和通信已成为现代社会的“命脉”。
通信工程专业英语论文
通信工程专业英语论文外文翻译(原文)The General Situation of AT89C51The AT89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4K bytes of Flash Programmable and Erasable Read Only Memory (PEROM) and 128 bytes RAM. The device is manufactured using Atmel’s high density nonvolatilememory technology and is compatible with the industry standard MCS-51?instruction set and pin out. The chip combines a versatile 8-bit CPU with Flash on a monolithic chip; the Atmel AT89C51 is a powerful microcomputer which provides a highly flexible and cost effective solution to many embedded control applications.Features:• Compatible with MCS-51? Products• 4K Bytes of In-System Reprogrammable Flash Memory• Endurance: 1,000 Write/Erase Cycles• Fully Static Operatio n: 0 Hz to 24 MHz• Three-Level Program Memory Lock• 128 x 8-Bit Internal RAM• 32 Programmable I/O Lines• Two 16-Bit Timer/Counters• Six Interrupt Sources• Programmable Serial Channel• Low Power Idle and Power Down ModesThe AT89C51 provides the following standard features: 4K bytes of Flash, 128 bytes of RAM, 32 I/O lines, two 16-bit timer/counters, a five vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator and clock circuitry. In addition, the AT89C51 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. 1外文翻译(原文)The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue functioning. The Power Down Mode saves the RAM contents but freezes the oscillator disabling all other chip functions until the next hardware reset.Block DiagramPin Description:VCC Supply voltage.GND Ground.Port 0:Port 0 is an 8-bit open drain bidirectional I/O port. As an output port eachpin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as high impedance inputs. (Sink/flow) Port 0 may also be configured to be the multiplexed low order address/data bus during accesses to external program and data memory. In this mode P0 has 2外文翻译(原文)internal pull-ups.Port 0 also receives the code bytes during Flash programming, and outputs the code bytes during program verification. External pull-ups are required during program verification.Port 1:Port 1 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 1 output buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pull-ups.Port 1 also receives the low-order address bytes during Flash programming and verification.Port 2 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 2 Port 2:output buffers can sink/source four TTL inputs. When 1s are written to Port 2 pins they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 2 pins that are externally being pulled low will source current (IIL) because of the internal pull-ups.Port 2 emits the high-order address byte during fetches fromexternal program memory and during accesses to external data memory that uses 16-bit addresses (MOVX @ DPTR). In this application it uses strong internal pull-ups when emitting 1s. During accesses to external datamemories that use 8-bit addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special Function Register.Port 2 also receives the high-order address bits and some control signals during Flash programming and verification.Port 3:Port 3 is an 8-bit bidirectional I/O port with internal pull-ups. The Port 3 output buffers can sink/source four TTL inputs. When 1s are written to Port 3 pins they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled low will source current (IIL) because of the pull-ups.3外文翻译(原文)Port 3 also serves the functions of various special features of the AT89C51 as listed below:Port 3 also receives some control signals for Flash programming and verification.RST:Reset input. A high on this pin for two machine cycles while the oscillator is running resets the device.ALE/PROG:Address Latch Enable output pulse for latching the low byte of theaddress during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming.In normal operation ALE is emitted at a constant rate of 1/6 the oscillator frequency, and may be used for external timing or clockingpurposes. Note, however, that one ALE pulse is skipped during each access to external Data Memory.If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in externalexecution mode.PSEN:Program Store Enable is the read strobe to external program memory. When the AT89C51 is executing code from external program memory, PSEN is activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memory.4外文翻译(原文)EA/VPP:External Access Enable. EA must be strapped to GND in orderto enable the device to fetch code from external program memorylocations starting at 0000H up to FFFFH. Note, however, that if lock bit 1(LB1) is programmed, EA will be internally latched (fasten with a latch) on reset.EA should be strapped to VCC for internal program executions.This pin also receives the 12-volt programming enable voltage(VPP) during Flashprogramming, for parts that require 12-volt VPP.XTAL1:Input to the inverting oscillator amplifier and input to the internal clock operating circuit.XTAL2:Output from the inverting oscillator amplifier.Oscillator Characteristics:XTAL1 and XTAL2 are the input and output, respectively, of an inverting amplifier which can be configured for use as an on-chip oscillator, as shown in Figure 1. Either a quartz crystal or ceramic resonator may be used. To drive the device from an external clock source, XTAL2 should be left unconnected while XTAL1 is driven as shown in Figure 2. There are no requirements on the duty cycle of the external clock signal, since the input to the internal clockingcircuitry is through a divide-by-two flip-flop, but minimum and maximum voltage high and low times specifications must be observed.Idle Mode:In idle mode, the CPU puts itself to sleep while all theon chip peripherals remain active. The mode is invoked by software. The content of the on-chip RAM and all the special functions registersremain unchanged during this mode. The idle mode can be terminated byany enabled interrupt or by a hardware reset.It should be noted that when idle is terminated by a hard ware reset, the device normally resumes program execution, from where it left off,up to two machine cycles before the internal reset algorithm takes control. On-chip hardware inhibits access to internal RAM in this event, but access to the port pins is not inhibited. To eliminate thepossibility of an unexpected write to a port pin when Idle is terminated by reset, the instruction following the one that invokes Idle 5 外文翻译(原文)should not be one that writes to a port pin or to external memory.Power Down ModeIn the power down mode the oscillator is stopped, and theinstruction that invokes power down isthe last instruction executed. The on-chip RAM and Special Function Registers retain their values until the power down mode is terminated. The only exit from power down is a hardware reset. Reset redefines the SFRs but does not change the on-chip RAM. The reset should not be activated before VCC is restored to its normal operating level and must be held active long enough to allow the oscillator to restart and stabilize.Program Memory Lock BitsOn the chip are three lock bits which can be left unprogrammed (U)or can be programmed (P) to obtain the additional features listed in the table below:When lock bit 1 is programmed, the logic level at the EA pin is sampled and latched during reset. If the device is powered up without a reset, the latch initializes to a random value, and holds that value until reset is activated. It is6外文翻译(原文)necessary that the latched value of EA be in agreement with the current logic level at that pin in order for the device to function properly.Programming the Flash:The AT89C51 is normally shipped with the on-chip Flashmemory array in the erased state (that is, contents = FFH) and ready to be programmed. The programming interface accepts either a high-voltage (12-volt) or alow-voltage (VCC) program enable signal. The low voltage programming mode provides a convenient way to program the AT89C51 inside the user’s system, whilethe high-voltage programming mode is compatible with conventional third party Flash or EPROM programmers.The AT89C51 is shipped with either the high-voltage or low-voltage programming mode enabled. The respective top-side marking and device signatureThe AT89C51 code memory array is programmed byte-bybyte in either programming mode. To program any nonblank byte in the on-chip Flash Programmable and Erasable Read Only Memory, the entire memory must be erased using the Chip Erase Mode.Programming Algorithm: Before programming the AT89C51, the address, data and control signals should be set up according to the Flash programming mode table and Figures 3 and 4. To program the AT89C51, take the following steps.1. Input the desired memory location on the address lines.2. Input the appropriate data byte on the data lines.3. Activate the correct combination of control signals.4. Raise EA/VPP to 12V for the high-voltage programming mode.7外文翻译(原文)5. Pulse ALE/PROG once to program a byte in the Flash array or thelock bits. The byte-write cycle is self-timed and typically takes nomore than 1.5 ms. Repeat steps 1 through 5, changing the address anddata for the entire array or until the end of the object file is reached.Data Polling: The AT89C51 features Data Polling to indicate the endof a write cycle. During a write cycle, an attempted read of the lastbyte written will result in the complement of the written datum on PO.7. Once the write cycle has been completed, true data are valid on all outputs, and the next cycle may begin. Data Polling may begin any time after a write cycle has been initiated.Ready/Busy: The progress of byte programming can also be monitoredby the RDY/BSY output signal. P3.4 is pulled low after ALE goes high during programming to indicate BUSY. P3.4 is pulled high again when programming is done to indicate READY.Program Verify: If lock bits LB1 and LB2 have not been programmed,the programmed code data can be read back via the address and data lines for verification. The lock bits cannot be verified directly.Verification of the lock bits is achieved by observing that theirfeatures are enabled.Chip Erase: The entire Flash Programmable and Erasable Read Only Memory array is erased electrically by using the proper combination of control signals and byholding ALE/PROG low for 10 ms. The code array is written with all “1”s. The chiperase operation must be executed before the code memory can be re-programmed.Reading the Signature Bytes: The signature bytes are read by the same procedure asa normal verification of locations 030H, 031H, and 032H, except that P3.6 and P3.7must be pulled to a logic low. The values returned are as follows.(030H) = 1EH indicates manufactured by Atmel(031H) = 51H indicates 89C51(032H) = FFH indicates 12V programming(032H) = 05H indicates 5V programming8外文翻译(原文)Programming InterfaceEvery code byte in the Flash array can be written and the entire array can be erasedby using the appropriate combination of control signals. The write operation cycle isselftimed and once initiated, will automatically time itself to completion.9单片机温度控制系统中英文翻译资料AT89C51的概况AT89C51是美国ATMEL公司生产的低电压，高性能CMOS8位单片机，片内含4Kbytes的快速可擦写的只读程序存储器(PEROM)和128 bytes 的随机存取数据存储器(RAM)，器件采用ATMEL公司的高密度、非易失性存储技术生产，兼容标准MCS-51产品指令系统，片内置通用8位中央处理器(CPU)和flish 存储单元，功能强大AT89C51单片机可为您提供许多高性价比的应用场合，可灵活应用于各种控制领域。
通信毕设中英文文献翻译
英文文献The Application of one point Multiple Access Spread SpectrumCommunication SystemLiu Jiangang, Nan yang City, Henan Province Electric Power Industry Bureau【ABSTRACT】Spread Spectrum Digital Microwave communication as a communication, because their excellent performance have been widely used. The article in Nan yang City Power Industry Bureau one point Multiple Access Spread Spectrum Communication System as an example. briefed the spread spectrum communications, the basic concept and characteristics of the power system communication applications.KEYWORDS：one point multiple access; Spread-spectrum communication; AttenuationNan yang City in the outskirts of Central cloth 35 to 11 kv substation farm terminals, their operation management rights belong to the Council East, Rural Power Company west (the eastern suburb of agricultural management companies -- four, the western suburbs of Rural Power Company Management 7), Scheduling of the various stations of the means of communication to the original M-150 radio and telephone posts. 2002 With the transformation of rural network, the remote station equipment into operation and communication channels to put a higher demand .As PUC Dispatch Communication Building to the east and west of farmers -- the difference between a company linked to fiber, Therefore, if 11 substations and the establishment of a transfer Link Building links Point may be the data and voice were sent to two rural power companies dispatch room, Rural Network scheduling for the implementation of automation to create the necessary conditions.Given the status and power grid substation level, nature, taking into account the carrier and optical-fiber communications to conduct multiple forwarding, increasing the instability factor, considering the cost and conditions of the urban construction, Finallydecided to adopt wireless spread-spectrum technology to establish that 11 farm terminal substation communication system. This paper describes the spread spectrum technology and the current system of the building.1.The basic concept of spread-spectrum communication.Spread Spectrum Communication's basic characteristics, is used to transmit information to the signal bandwidth (W) is far greater than the practical information required minimum (effective) bandwidth (△ F) , as the ratio of processing gain GP .G P = W/△FAs we all know, the ordinary AM, FM, or pulse code modulation communications, GP values in the area more than 10 times, collectively, the "narrow-band communication", and spread-spectrum communications GP values as high as hundreds or even thousands of times, can be called "broadband communications."Due to the spread-spectrum signal, it is very low power transmitters, transmission space mostly drowned in the noise, it is difficult to intercepted by the other receiver, only spreading codes with the same (or random PN code) receiver, Gain can be dealt with, and dispreading resume the original signal.2.The technology superiority of spread-spectrum communication.Strong anti-interference, bit error rate is low. As noted above, the spread spectrum communication system due to the expansion of the transmitter signal spectrum, the receiver dispreading reduction signal produced spreading gain, thereby greatly enhancing its interference tolerance. Under the spreading gain, or even negative in the signal-to-noise ratio conditions, can also signal from the noise drowned out Extraction, in the current business communications systems, spread spectrum communication is only able to work in a negative signal-to-noise ratio under the conditions of communication.Anti-multi-path interference capability, increase the reliability of the system. Spread-spectrum systems as used in the PN has a good correlation, correlation is very weak. different paths to the transmission signal can easily be separated and may in time and re-alignment phase, formation of several superimposed signal power, thereby improving the system's performance to receive increased reliability of the system.Easy to use the same frequency, improving the wireless spectrum utilization.Wireless spectrum is very valuable, although long-wave microwave have to be exploited, and still can not meet the needs of the community. To this end, countries around the world are designed spectrum management, users can only use the frequency applications, rely on the channel to prevent the division between the channel interference.Due to the use of spread-spectrum communication related receive this high-tech, low signal output power ( "a W, as a general-100 mW), and will work in the channel noise and thermal noise in the background, easy to duplicate in the same area using the same frequency, can now all share the same narrow-band frequency communications resources.Spread spectrum communication is digital communications, particularly for digital voice and data transmission while, spread spectrum communication with their own encryption, only in the same PN code communication between users, is good for hiding and confidential in nature, facilitating communications business . Easy to use spread-spectrum CDMA communications, voice compression and many other new technologies, more applicable to computer networks and digitization of voice, image information transmission.Communication is the most digital circuits, equipment, highly integrated, easy installation, easy maintenance, but also very compact and reliable. The average failure rate no time was very long.We have decided to adopt the spread-spectrum communication technology construction of 11 farm terminal substation communications system, Due to the spread-spectrum communication by the line-of-sight transmission distance restrictions, has become unstoppable system design premise.If the PUC scheduling Building and 11 substations have stopped, and the problem becomes more complicated, use spread spectrum system on the feasibility greatly reduced. Therefore, we look at the city Aerial topographical map, initially identified has not stopped to consider systems design, and requests the companies used this equipment Spread Spectrum 11 points transmission routing of the measured and the results have been satisfactory.Then spread spectrum wireless equipment market supply of cash, initially, weselected a series of Spread Spectrum Comlink third generation products. Because most of the point-to-point mode, Merit functions of the spread-spectrum equipment in a point-to-multipoint application environments encountered many problems: First is the issue of frequency resources. Even a minimum of 64 kbit / s data rate radio, space also occupied bandwidth 5 MHz, Because 32 of the PN code isolation is only about 15 dBm, the project had to use frequency division multiple access 35 db to get around the theoretical isolation. 11 stations will use 11 frequencies, frequency greater waste of resources. Comlink and Spread Spectrum products in the same frequency to achieve a point-to-multipoint communications.Second antenna erection problems, point-to-point equipment for the main radio station, the main station need to set up a number of terminal antennas, the vast majority of domestic engineering companies used by the U.S. Conifer 24 dBi parabolic semi-cast magnesium grid directional antenna. vertical polarization - 1 m wide, it is difficult to top the layout and avoid flap and the mutual interference, Although the project can be set up to take stratified, or through cooperation and on the road to one or more Omni directional antenna launch, However, as construction of a road and the signal attenuation, transmission result is not satisfactory.In addition, the RF cable lying, The application of network management software such factors we have also decided to adopt the final 1:00 Comlink Multiple Access Spread Spectrum products. Its system configuration, as shown in Figure 2:3.Routing AnalysisCombining visual distance access and use the radio and antenna gain, cable attenuation and environmental factors, and testing the design is reasonable, determinethe attenuation affluent channel capacity. Spread spectrum microwave link attenuation depends on the reliability margin.Attenuation margin calculation formula : F G= G SG + G ANT - L GL - L PLF G——Attenuation margin ；G SG——System Gain (dB）；G ANT——Antenna Gain (dBi）；L GL——Connectors and cables attenuation (dB)；L pL—— Channel attenuation (dB）。
全球定位系统的介绍 --通信工程外文翻译
毕业设计（论文）外文参考资料及译文译文题目：Introduction to the Global Positioning System全球定位系统的介绍学生姓名：学号：专业：通信工程所在学院：指导教师：职称：201x年 xx月xx日Introduction to the Global Positioning System---------From “Corvallis Microtechnology, Inc. 1996”Chapter One: What is GPS?The Global Positioning System (GPS) is a location system based on a constellation of about 24 satellites orbiting the earth at altitudes of approximately 11,000 miles. GPS was developed by the United States Department of Defense (DOD), for its tremendous application as a military locating utility. The DOD's investment in GPS is immense. Billions and billions of dollars have been invested in creating this technology for military uses. However, over the past several years, GPS has proven to be a useful tool in non-military mapping applications as well.GPS satellites are orbited high enough to avoid the problems associated with land based systems, yet can provide accurate positioning 24 hours a day, anywhere in the world. Uncorrected positions determined from GPS satellite signals produce accuracies in the range of 50 to 100 meters. When using a technique called differential correction, users can get positions accurate to within 5 meters or less.Today, many industries are leveraging off the DOD's massive undertaking. As GPS units are becoming smaller and less expensive, there are an expanding number of applications for GPS. In transportation applications, GPS assists pilots and drivers in pinpointing their locations and avoiding collisions. Farmers can use GPS to guide equipment and control accurate distribution of fertilizers and other chemicals. Also，GPS is used for providing accurate locations and as a navigation tool for hikers, hunters and boaters.Many would argue that GPS has found its greatest utility in the field of Geographic Information Systems (GIS). With some consideration for error, GPS can provide any point on earth with a unique address (its precise location). A GIS is basically a descriptive database of the earth (or a specific part of the earth). GPS tells you that you are at point X,Y,Z while GIS tells you that X,Y,Z is an oak tree, or a spot in astream with a pH level of 5.4. GPS tells us the "where". GIS tells us the "what". GPS/GIS is reshaping the way we locate, organize, analyze and map our resources.Chapter Two: Trilateration - How GPS Determines a LocationIn a nutshell, GPS is based on satellite ranging - calculating the distances between the receiver and the position of 3 or more satellites (4 or more if elevation is desired) and then applying some good old mathematics. Assuming the positions of the satellites are known, the location of the receiver can be calculated by determining the distance from each of the satellites to the receiver. GPS takes these 3 or more known references and measured distances and "triangulates" an additional position.As an example, assume that I have asked you to find me at a stationary position based upon a few clues which I am willing to give you. First, I tell you that I am exactly 10 miles away from your house. You would know I am somewhere on the perimeter of a sphere that has an origin as your house and a radius of 10 miles. With this information alone, you would have a difficult time to find me since there are an infinite number of locations on the perimeter of that sphere.Second, I tell you that I am also exactly 12 miles away from the ABC Grocery Store. Now you can define a second sphere with its origin at the store and a radius of 12 miles. You know that I am located somewhere in the space where the perimeters of these two spheres intersect - but there are still many possibilities to define my location.Adding additional spheres will further reduce the number of possible locations. In fact, a third origin and distance (I tell you am 8 miles away from the City Clock) narrows my position down to just 2 points. By adding one more sphere, you can pinpoint my exact location. Actually, the 4th sphere may not be necessary. One of the possibilities may not make sense, and therefore can be eliminated.For example, if you know I am above sea level, you can reject a point that has negative elevation. Mathematics and computers allow us to determine the correct point with only 3 satellites.Based on this example, you can see that you need to know the following information in order to compute your position:A) What is the precise location of three or more known points (GPS satellites)?B) What is the distance between the known points and the position of the GPS receiver?Chapter Three: How the Current Locations of GPS Satellites are Determined GPS satellites are orbiting the Earth at an altitude of 11,000 miles. The DOD can predict the paths of the satellites vs. time with great accuracy. Furthermore, the satellites can be periodically adjusted by huge land-based radar systems. Therefore, the orbits, and thus the locations of the satellites, are known in advance. Today's GPS receivers store this orbit information for all of the GPS satellites in what is known as an almanac. Think of the almanac as a "bus schedule" advising you of where each satellite will be at a particular time. Each GPS satellite continually broadcasts the almanac. Your GPS receiver will automatically collect this information and store it for future reference.The Department of Defense constantly monitors the orbit of the satellites looking for deviations from predicted values. Any deviations (caused by natural atmospheric phenomenon such as gravity), are known as ephemeris errors. When ephemeris errors are determined to exist for a satellite, the errors are sent back up to that satellite, which in turn broadcasts the errors as part of the standard message, supplying this information to the GPS receivers.By using the information from the almanac in conjuction with the ephemeris error data, the position of a GPS satellite can be very precisely determined for a given time.Chapter Four: Computing the Distance Between Your Position and the GPSSatellitesGPS determines distance between a GPS satellite and a GPS receiver by measuring the amount of time it takes a radio signal (the GPS signal) to travel from the satellite to the receiver. Radio waves travel at the speed of light, which is about 186,000 miles per second. So, if the amount of time it takes for the signal to travel from the satellite to the receiver is known, the distance from the satellite to the receiver (distance = speed x time) can be determined. If the exact time when the signal was transmitted and the exact time when it was received are known, the signal's travel time can be determined.In order to do this, the satellites and the receivers use very accurate clocks which are synchronized so that they generate the same code at exactly the same time. The code received from the satellite can be compared with the code generated by the receiver. By comparing the codes, the time difference between when the satellite generated the code and when the receiver generated the code can be determined. This interval is the travel time of the code. Multiplying this travel time, in seconds, by 186,000 miles per second gives the distance from the receiver position to the satellite in miles.Chapter Five: Four (4) Satellites to give a 3D positionIn the previous example, you saw that it took only 3 measurements to "triangulate" a 3D position. However, GPS needs a 4th satellite to provide a 3D position. Why?? Three measurements can be used to locate a point, assuming the GPS receiver and satellite clocks are precisely and continually synchronized, thereby allowing the distance calculations to be accurately determined. Unfortunately, it is impossible to synchronize these two clocks, since the clocks in GPS receivers are not as accurate as the very precise and expensive atomic clocks in the satellites. The GPS signals travel from the satellite to the receiver very fast, so if the two clocks are off by only a small fraction, the determined position data may be considerably distorted.The atomic clocks aboard the satellites maintain their time to a very high degree ofaccuracy. However, there will always be a slight variation in clock rates from satellite to satellite. Close monitoring of the clock of each satellite from the ground permits the control station to insert a message in the signal of each satellite which precisely describes the drift rate of that satellite's clock. The insertion of the drift rate effectively synchronizes all of the GPS satellite clocks.The same procedure cannot be applied to the clock in a GPS receiver. Therefore, a fourth variable (in addition to x, y and z), time, must be determined in order to calculate a precise location. Mathematically, to solve for four unknowns (x,y,z, and t), there must be four equations. In determining GPS positions, the four equations are represented by signals from four different satellites.Chapter Six: The GPS Error BudgetThe GPS system has been designed to be as nearly accurate as possible. However, there are still errors. Added together, these errors can cause a deviation of +/- 50 -100 meters from the actual GPS receiver position. There are several sources for these errors, the most significant of which are discussed below:Atmospheric ConditionsThe ionosphere and troposphere both refract the GPS signals. This causes the speed of the GPS signal in the ionosphere and troposphere to be different from the speed of the GPS signal in space. Therefore, the distance calculated from "Signal Speed x Time" will be different for the portion of the GPS signal path that passes through the ionosphere and troposphere and for the portion that passes through space.As mentioned earlier, GPS signals contain information about ephemeris (orbital position) errors, and about the rate of clock drift for the broadcasting satellite. The data concerning ephemeris errors may not exactly model the true satellite motion or the exact rate of clock drift. Distortion of the signal by measurement noise can further increase positional error. The disparity in ephemeris data can introduce 1-5 meters ofpositional error, clock drift disparity can introduce 0-1.5 meters of positional error and measurement noise can introduce 0-10 meters of positional error.Ephemeris errors should not be confused with Selective Availability (SA), which is the intentional alteration of the time and ephemeris signal by the Department of Defense.A GPS signal bouncing off a reflective surface prior to reaching the GPS receiver antenna is referred to as multipath. Because it is difficult to completely correct multipath error, even in high precision GPS units, multipath error is a serious concern to the GPS user.Chapter Seven: Measuring GPS AccuracyAs discussed above, there are several external sources which introduce errors into a GPS position. While the errors discussed above always affect accuracy, another major factor in determining positional accuracy is the alignment, or geometry, of the group of satellites (constellation) from which signals are being received. The geometry of the constellation is evaluated for several factors, all of which fall into the category of Dilution Of Precision, or DOP.DOP is an indicator of the quality of the geometry of the satellite constellation. Your computed position can vary depending on which satellites you use for the measurement. Different satellite geometries can magnify or lessen the errors in the error budget described above. A greater angle between the satellites lowers the DOP, and provides a better measurement. A higher DOP indicates poor satellite geometry, and an inferior measurement configuration.Some GPS receivers can analyze the positions of the satellites available, based upon the almanac, and choose those satellites with the best geometry in order to make the DOP as low as possible. Another important GPS receiver feature is to be able to ignore or eliminate GPS readings with DOP values that exceed user-defined limits. Other GPS receivers may have the ability to use all of the satellites in view, thus minimizing the DOP as much as possible.全球定位系统的介绍----摘自Corvallis Microtechnology公司，1996第一章：什么是GPS？全球定位系统（ＧＰＳ）是一种基于２４颗高度大约１１０００英里的地球轨道卫星的定位系统。
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用于多跳认知无线电网络的分布式网络编码控制信道Alfred Asterjadhi等著1 前言大多数电磁频谱由政府机构长期指定给公司或机构专门用于区域或国家地区。
由于这种资源的静态分配，许可频谱的许多部分在许多时间和/或位置未使用或未被充分利用。
另一方面，几种最近的无线技术在诸如IEEE802.11，蓝牙，Zigbee之类的非许可频段中运行，并且在一定程度上对WiMAX进行操作;这些技术已经看到这样的成功和扩散，他们正在访问的频谱- 主要是2.4 GHz ISM频段- 已经过度拥挤。
为了为这些现有技术提供更多的频谱资源，并且允许替代和创新技术的潜在开发，最近已经提出允许被许可的设备（称为次要用户）访问那些许可的频谱资源，主要用户未被使用或零星地使用。
这种方法通常被称为动态频谱接入（DSA），无线电设备发现和机会性利用未使用或未充分利用的频谱带的能力通常称为认知无线电（CR）技术。
DSA和CR最近都引起了无线通信和网络界的极大关注。
通常设想两种主要应用。
第一个是认知无线接入（CW A），根据该认知接入点，认知接入点负责识别未使用的许可频谱，并使用它来提供对次用户的接入。
第二个应用是我们在这个技术中研究的应用，它是认知自组织网络（CAN），也就是使用用于二级用户本身之间通信的无许可频谱，用于诸如点对点内容分发，环境监控，安全性等目的，灾难恢复情景通信，军事通信等等。
设计CAN系统比CW A有更多困难，主要有两个原因。
第一是识别未使用的频谱。
在CW A中，接入点的作用是连接到互联网，因此可以使用简单的策略来推断频谱可用性，例如查询频谱调节器在其地理位置的频谱可用性或直接与主用户协商频谱可用性或一些中间频谱经纪人另一方面，在CAN中，与频谱调节器或主要用户的缺乏直接通信需要二级用户能够使用检测技术自己识别未使用的频谱。
第二个困难是辅助用户协调媒体访问目的。
在CW A中存在接入点和通常所有二级用户直接与之通信（即，网络是单跳）的事实使得直接使用集中式媒体接入控制（MAC）解决方案，如时分多址（TDMA）或正交频分多址（OFDMA）。
相反，预计CAN将跨越多跳，缺少集中控制器;而对于传统的单通道多跳自组织网络而言，这个问题的几个解决方案是已知的，因为假设我们处理允许设备访问的具有成本效益的最先进技术的状态，因此将它们重用于CAN是不直接的一次只能限制频谱的一部分，中间访问将在多个信道上执行，而且可用于二次通信的实际信道可能会随着位置和时间而变化。
由于刚刚描述的两个问题，CAN中出现了几个实际的设计挑战，如实现控制信道，辅助用户对媒体接入的协调，实现用于检测未使用频谱的可靠方案等。
在这篇文章中，我们将讨论这些挑战，我们显示，在以前的文献中，有几个很好的解决方案可以有效地解决一个或者一些这些问题。
在讨论之后，我们提出了我们设计的方案，以克服CAN缺乏完整的解决方案。
我们的方案是基于一个虚拟控制通道，利用用户以伪随机方式访问信道，并在任何频道遇到任何情况时交换控制信息。
通过网络编码实现对所有用户的控制信息的高效传播。
用户交换的控制信息包括根据预定义的确定性算法确定信道切换模式以及数据通信的资源分配所需的所有信息（带宽要求，主要用户存在和位置等）。
我们通过提出和讨论模拟结果来讨论所提出的方案的性能，表明它是CAN实际实现的有效解决方案。
2 多功能CAN中的技术挑战我们在CAN中遇到的第一个问题是鸡蛋问题：二次设备需要彼此协调来执行频谱接入，但是它们还需要访问频谱以便通信和实现协调。
这个问题通常被称为控制频道问题，不幸的是，在与DSA相关的工作中往往被忽视。
事实上，大多数DSA相关出版物更侧重于主要用户检测和/或高效频谱分配的问题，并且在这样做时，假设某些控制信道实现对于次要用户是可用的。
为了实际实现控制通道，一些作者提出静态分配一些频谱带。
这个实际提出了两个主要问题：一是需要静态频谱调节，这正是DSA旨在避免的一个问题。
第二，选择的控制带可能很容易成为瓶颈。
这在多跳场景中尤其如此，其中对控制信息交换的需求潜在地非常高（例如，不仅对于媒体访问，而且用于路由目的）。
已经提出了一些其他解决方案，其尝试通过动态地选择未使用的许可频带来执行次要用户控制来解决第一个问题沟通;然而，这些建议没有解决控制瓶颈问题。
当然，CAN的理想解决方案不仅需要解决控制信息交换的问题，而且还要有效地实现对可用频谱资源的有效利用。
在这方面，应该注意的是，先前讨论的多重会合策略最初被提出作为单通道技术的扩展，最着名的是IEEE 802.11;特别地，在这些解决方案中看到的优点是仅仅通过使用多个通道，可以在单通道情况下实现网络容量的显着增加。
然而，要注意的是，多通道网络的容量限制还远远没有达到多重交会方案，这更是解决问题的实际方法，而不采取系统的方法来最大限度地提高信道利用效率。
应该考虑到频谱有效使用的一个方面是在多跳网络中，通常只有一部分用户处于给定用户的干扰范围内。
这通过频率重用来提高频谱利用率的可能性。
不幸的是，在实践中，这需要更复杂的频谱分配策略，以及更多信息的可用性（例如每个用户的位置知识）。
以分布式的方式是非常具有挑战性的。
与此相关的问题是链路调度和路由问题：传统的自组织网络路由策略在多信道网络中是无效的，主要是因为给定的链路在任何时候都不能被激活，因为要求发送方和接收器在同一个通道上。
理想情况下，应共同执行信道分配，链路调度和路由，以最大化频谱利用效率和网络性能。
在这方面，已经提出了一些有趣的解决方案，但是它们具有要求集中式调度器的缺点。
鉴于CAN的性质，需要一种分布式解决方案来实现实施。
到目前为止，我们还没有处理可能最具特色的CAN的特征：适用于二次频谱接入的频谱的这些部分的识别必须由次要用户自己使用感测技术来执行。
从最近的文献中已经深入研究了从单个二次用户的角度进行感测的主题，并且已经提出了从简单的能量或匹配滤波器检测到复杂的循环平稳特征检测技术的几种解决方案。
然而，如对于无线电接入频谱的情况所讨论的，对主要用户的二次干扰维持在一定阈值以下的要求转化为对单用户检测策略的灵敏度要求高到不符合成本效益，或者甚至完全不切实际，用现有技术实现这种检测器。
3 多功能CAN中的DSA方案我们考虑每个次要用户具有单个收发器的情况，因此可以在任何给定时间仅在单个信道上进行调谐。
我们有一套次要用户和一组可用于无牌访问的渠道。
为了设计在这种情况下有效的频谱接入方案，我们需要解决以下两个问题：如何使二级用户彼此协调，以及如何以有效的方式为这些用户分配频谱资源。
如上一节所述，这一领域的大多数以前的工作只解决了其中一个问题;相反，我们的方法旨在同时解决这两个问题。
直观地，频谱分配和传输调度最好使用关于特定通信需求（例如，服务质量[QoS]要求）和频谱可用性的知识来执行（例如，由主用户检测信息）。
将这些知识称为控制信息，通过收集所有用户生成的控制包获得。
在文献中，当完整的控制信息用于资源分配时，通常假定集中式方案。
这意味着有一个集中控制器收集所有用户生成的控制包，确定全球资源分配，然后告诉每个用户什么资源用于数据通信。
为了得出分布式方法，我们选择不同的策略：每个用户收集完整的控制信息，并为整个网络独立地确定资源分配。
关键在于，如果相同的控制信息成功传播给所有用户，并且资源分配算法是确定性的，则每个用户将能够确定相同的资源分配，而无需用户之间的任何进一步的交互。
这是我们首先提出的单跳多通道网络的多通道方案的基本原理，并在此讨论在多跳CAN中的使用。
在本节的其余部分，我们提供更多关于我们的计划如何工作的细节;本文的其余部分更侧重于多机场和机场频谱接入问题。
控制信息的确切性质由所选择的特定调度算法确定。
作为一个例子，在我们讨论了一种相对简单的单跳网络统一资源分配算法。
该算法仅需要参与参与分配的用户组的知识以及用于确定伪随机信道切换模式的随机数发生器的种子。
因此，由每个用户生成的控制信息分组仅包括用户的唯一标识符（例如，其MAC 地址）和使用的随机比特串以及所有其他用户的比特串来确定公共种子为随机数发生器。
我们的方案正常工作的一个重要要求是控制信息的传播到达所有用户。
每当特定用户在分配周期结束时无法检索控制信息时，该用户将潜在地确定用于后续分配周期的错误的信道切换模式和传输调度，可能开始使用资源（某些信道中的传输时隙）的传输将其分配给其他用户。
在本文的其余部分中，我们将此事件称为频谱冲突，并参考无法将控制信息检索为误传用户的用户。
一般来说，频谱冲突的机会，因此频谱资源浪费的平均数量随着用户数量的错误而增加。
因此，我们想要一种传播方案，其中定义为普通用户从所有其他用户成功检索控制信息的概率的检索成功概率很高。
我们建议使用网络编码，以便为控制信息实施可靠而有效的传播方案。
网络编码是最近推出的用于数据传播的范例，根据该模式，由多个源产生的分组在中间节点处共同编码并在最终目的地解码。
该编码策略可以在增加吞吐量，减少延迟和提高鲁棒性方面非常有效。
为了实现网络编码的实际，我们提到，作者提出了一种网络编码分布式方案，消除了对编码和解码功能的集中化知识的需要，同时允许节点间的异步数据交换。
根据该方法，每个节点将所有传入的分组存储在内部缓冲器中，并且在其自己的缓冲器中发送包含所有分组的随机线性组合的编码分组。
在传输时间，该分组被转发到位于传输范围内的所有节点。
现在，如果编码矢量是随机生成的，并且符号位于足够大小的有限伽罗瓦域，则信息将以高概率传播给所有用户。
基于这种方法，每当节点接收到编码的分组时，它必须知道用于执行编码的系数，以便恢复原始信息分组。
一个简单的解决方案包括在每个编码包中附加对应的编码矢量，该编码矢量描述了其包含的信息包的哪个线性组合。
这样，解码存储在编码包中的信息所需的编码系数可以在编码包本身内找到。
任何节点都可以恢复信息包由所有节点简单地通过反转存储在数据传播期间接收的分组的所有系数的矩阵来产生。
将编码向量追加到数据包引起额外的开销，这将需要在确定我们的DSA解决方案的总体控制开销时予以考虑;有关这个问题的详细讨论，请参阅读者。
最后，为了实现网络编码的实际，我们采用缓冲模型。
如我们以前的工作中所讨论的，网络编码大大优于其他策略，以便在单跳多通道网络中传播控制信息。
换句话说，使用网络编码与伪随机信道切换模式相结合，为我们提供了一个虚拟控制信道，允许用户有效地共享控制信息。
该网络编码的虚拟控制信道对于分组丢失和链路故障是鲁棒的，并且最重要的是不需要存在专用于交换控制信息的静态频谱资源。
对于适用于二次接入的未使用频谱资源的检测，我们注意到，网络编码控制信道自然适合实施协同主用户检测解决方案。
4。
结论在本文中，我们讨论了CAN中出现的主要挑战，并提出了基于虚拟网络编码控制通道的这些挑战的实际解决方案。