【正文】 中文 4700 字 本科畢業(yè)設(shè)計(jì)（論文） —— 英文 翻譯 題 目 學(xué)生姓名 專業(yè)班級(jí) 通信工程 052 學(xué) 號(hào) 12 院 （系） 計(jì)算機(jī)與通信工程學(xué)院 指導(dǎo)教師 完成時(shí)間 2021年 4 月 26日 1 英文原文 : Data munications Gildas Avoine and Philippe Oechslin EPFL, Lausanne, Switzerland , Abstract Data munications are munications and puter technology resulting from the bination of a new means of munication. To transfer information between the two places must have transmission channel, according to the different transmission media, there is wired data munications and wireless data munications division. But they are through the transmission channel data link terminals and puters, different locations of implementation of the data terminal software and hardware and the sharing of information resources. 1 The development of data munications The 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. The history of modern data munications Communication as a Telemunications are from the 19th century, the beginning Year 30. Faraday discovered electromagic induction in 1831. Morse invented telegraph in 1837. Maxwell39。s electromagic theory in 1833. Bell invented the telephone in 1876. Marconi invented radio in 1895. Tele has opened up in the new era. Tube invented in 1906 in order to simulate the development of theorem of Nyquist criteria In 1928. Shannong theorem in 1948. The invention of the 20th century, the 2 semiconductor 50, thereby the development of digital munications. 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 munications. The invention of the 20th century, 60 laser, intended to be used for munications, was not successful. 70 The invention of the 20th century, optical fiber, optical fiber munications can be developed. Key figures Bell (18471922), 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 (18741937), Italian people, in 1894, the pilot at his father39。s estate. 1896, to London. In 1897, the pany set up the radio reported. In 1899, the first time the British and French wireless munications. 1916, implementation of shortwave radio munications. 1929, set up a global wireless munications work. Kim won the Nobel Prize. Took part in the Fascist Party. Classification of Communication Systems According to type of information: Telephone munication system, Cable television system ,Data munication systems. Modulation by sub: Baseband transmission,Modulation transfer. Characteristics of transmission signals in accordance with sub: Analog Communication System ,Digital munication system. Transmission means of munication system: Cable Communications,Twisted pair, coaxial cable and so on. And longdistance telephone munication. Modulation: SSB / FDM. Based on the PCM time division multiple coaxial digital baseband transmission technology. Will gradually replace the coaxial fiber. Microwave relay munications:Comparison of coaxial and easy to set up, low investment, shortcycle. Analog phone microwave munications mainly SSB / FM / 3 FDM modulation, munication capacity of 6,000 road / Channel. Digital microwave using BPSK, QPSK and QAM modulation techniques. The use of 64QAM, 256QAM such as multilevel modulation technique enhance the capacity of microwave munications can be transmitted at 40M Channel 1920 ~ 7680 Telephone Rd PCM figure. Optical Fiber Communication: Optical fiber munication is the use of lasers in optical fiber transmission characteristics of longdistance with a large munication capacity, munication, long distance and strong antiinterference characteristics. Currently used for local, long distance, trunk transmission, and progressive development of fiberoptic munications work users. At present, based on the longwave lasers and singlemode optical fiber, each fiber road approach more than 10,000 calls, optical fiber munication itself is very strong force. Over the past decades, optical fiber munication technology develops very quickly, and there is a variety of applications, access devices, photoelectric conversion equipment, transmission equipment, switching equipment, work equipment and so on. Fiberoptic munications equ