通信原理论文

Shallow knowledge of communication engineeringIn the late 1950s, the advent of the computer and popularization, the information's influence on the society as a whole gradually increase to an absolute important position. The amount of information, information transmission speed, the speed of information processing and application degree of information are growing in the form of geometric series.The 21st century is an information-based economy and prosperity of the new century, it is an era of information explosion, everyday we come into contact with the voluminous information, the information sources, such as Internet, mobile phones, TV, newspaper, the people around you, and so on, can say information has been deeply integrated into our lives, we have not information. , according to scientists from junk emails to annoying ads, we every day "bombardment" by the vast amounts of information. Scientists in the United States to calculate a person on an average day for the amount of data. They found that the average human daily via television, radio,newspapers, posters and email for the amount of data that is equivalent to 174 newspaper reading. The study also found that the world's libraries, computers, DVD and newspaper contains the amount of data of 295 trillion bytes. If these data will be stored in a cd-rom, CD piled on the height equivalent to the distance between the earth and the moon, and the amount of data is in constant increase.So, in this rapidly changing information in the era of information, confused everyone that all walks of life should be how to face such a situation? I think that must be associated with information technology in the industry, so as to achieve more efficient, more rapid response, to adapt to the rapidly changing social needs.Across the electronics, communication engineering, computer science courses completed with the characteristics of both need a good base for mathematics, physics, and strong ability of hands-on application. Some courses, such as data structure,operating system, database, belongs to the computer class, others, such as signal processing, high frequency circuit, circuit principle belongs to electronics, and the communication principle between the professional foundation courses, such as learning scope is wide. Need we students have strong logical thinking ability, especially suitable for those students with deep understanding and analytical. Professional division is thinner, the professional can "soft" can "hard", tend to computer and electronic two directions respectively. Communication engineering is the information and the rapid development of science and technology and a dynamic field, especially digital mobile communications, optical fiber communication, Internet, network communication makes people in the passing information and access to information has reached unprecedented convenience degree. A decade ago, Hong Kong and Taiwan gang bosses in the film can be used to hit the "big brother" of people, already became so thin light, colorful, and into the hand of ordinary people; Previously only months flyingpigeon biography books can contact foreign friends can use the simple and convenient and quick E-mail and greetings, instant messaging, and even a network meeting on camera! All this should be attributed to the rapid development of communication engineering technology. Communication engineering, therefore, is to promote the development of information technology has helped.Information technology and communication technology is complementary to each other, communication technology is a modern sound, light, electricity technology as the foundation of hardware, supplemented by the corresponding software to achieve information exchange. The end of last century, multimedia, the application of the Internet has greatly promoted the spread of the development of communication engineering specialty, looking forward to early this century, broadband technology, optical communication also has emerged. Today, these techniques have been developed more mature, we surf the Internet today largely use broadband Internet access,is also benefiting from the development of these technologies, we now can have life rich and colorful Internet.Our communication engineering is divided into two subjects, one is biased towards the transmission of "communication and information system", the other one is to the decoding of the signal and information processing. This all have great relationship with information technology.Communication engineering in the field of another, is this on the one hand, it is important to computer and network technology, computer network refers to the different geographical position has independent function of computer and its peripheral equipment, through the communication lines connected, in a network operating system, network management software and network management and coordination of communication protocol, realize resources sharing and information transmission of computer system.Function of the computer network is mainly manifested in thehardware resource sharing, the software resource sharing and information exchange between users in three aspects.1. The hardware resource sharing. Can be dealt with within the scope of the entire network to provide the resources, storage resources, expensive equipment such as input and output of resources sharing, the user to save investment, also facilitate centralized management and balanced share the load.2. The software resource sharing. Allows users of the Internet to remote access to all kinds of large database, you can get the network file transfer service, remote process management services and remote file access service, so as to avoid the repeated labor in the software development and data resources repetition of storage, also facilitate centralized management.3. The information exchange between users. Across a computer network for distribution in the user provides a powerful means of communication. The user can send an email through thecomputer network, publish news and e-commerce activities. Communication engineering for another important contribution in the field of information lies in satellite communications, especially in China's big dipper satellite program is a powerful explanation Beidou satellite navigation system is developed by China's regional active 3 d satellite positioning and communication system (CNSS), is in addition to the U.S. global positioning system (GPS), the third after Russia's GLONASS satellite navigation system. But on a global scale with high precision, all-weather, for all kinds of users throughout the high reliable positioning, navigation and timing services, and with short message communication skills. The eighth and ninth beidou satellite in 2011, was the long March 3 a rocket into space is scheduled to transfer orbit. In December 2011, the beidou satellite navigation system, a spokesman for RanCheng its said the beidou satellite navigation system will be formed in the 2020 global coverage. In recent years the development of satellite communication technologyemerge in endlessly. Such as very small earth station antenna (VSAT) system, the movement of the low and middle orbit satellite communication system has received widespread attention and application. Satellite communication is an important part of global information highway in the future. It with its wide coverage, large capacity of communication. Communication distance, without being limited by the geographical environment, high quality and economic benefit, etc. The application in our country for the first time in 1972, and the rapid development, together with the optical fiber communication, digital microwave communication, became the mainstay of the contemporary long distance communication in our country.Satellite communication because it is not limited by geographical condition, with flexible mobility, so is still in accordance with its advantages of innovation and development. But also by the challenge of the rapid development of optical fiber communication, it is larger than the capacity ofsatellite communications, the transmission rate is high, there are a lot of overseas communications were replaced by a submarine cable, main land also has a similar situation. In mid and late 1990 s Satellite television Broadcast (DBs, Direct Broadcast Satellite or DTH - Direct To the Home), Satellite voice Broadcast, Satellite mobile communication and Satellite broadband multimedia communication becomes the new four development trend.Satellite communications development trend of the general development direction of large capacity, high power, high speed, broadband, low cost and high transmitting frequency, the repeater, multipoint beam and informs the beam, the application of the star on the switching signal processing technology, signal processing, etc., satellite live TV in the 21st century (DBS, TV), personal mobile satellite communications, multimedia satellite communication, satellite audio broadcast, satellite network TV will be a lot of development. VSAT business scope expands unceasingly, deep into every field of nationaleconomy, more show its economic and social benefits, ka-band application further miniaturization of equipment, of course also brought attenuation serious defects. Optical communication application in satellite communication gradually become mature, it requires precise satellite control technology, the current in the world is still in the development stage, is expected soon will enter the practical stage. Satellite communication in China is in rapid development, expanding the application areas of satellite communication, in addition to the financial, securities, post and telecommunications, meteorology, earthquake and other departments, remote education, remote medical treatment, emergency disaster relief, emergency communications, emergency broadcasting, land, sea and air navigation, connect to the Internet network telephone, TV and so on will be widely used. Satellite launch technology in our country, leads the world in long march rockets, big thrust, pollution-free, non-toxic environmentally friendly rocket engine has beensuccessful in our country, this for the development of our country's large communication satellites and manned spaceflight, lunar exploration project has created favorable conditions.In the market, due to the development of the industry too fast, the demand for talent and is quite large, is a professional "the easiest way to find a good job". So for the future, we, the sophomore, is of great power.。