Communication systems and information theory

Communication theory deals primarily with systems for transmitting information from one point to another. The source output might represent a voice waveform, a sequence of binary digits from a magnetic tape, he output of a set of sensors in a space probe, or a target in a radar system. The channel might represent a telephone line, a high frequency radio link, a space communication link, or a storage medium.

As it is known, in the early 1940’s a mathematical theory for dealing more fundamental aspects of communication systems was developed. The distinguishing characteristics of this theory are, first, a great emphasis on the theory of probability and, second, a primary concern with the encoder and decoder, both in terms of their functional roles and in terms of their achieving a given level of performance. In the past 20 years, information theory has been made more precise, has been extended and brought to the point where it is being applied in practical communication systems.

Much of modern communication theory stems from works of communication systems as well as from desirability of modelling both signal and noise as random processes. N. Wiener was interested in finding the best linear filter to separate the signal from additive noise with a prescribed delay. His work had an important influence on subsequent research in modulation theory.

Information technology (IT) is the study, design, development, implementation, support or management of computer-based information systems, particularly software applications and computer hardware. Information technology deals mainly with the use of electronic computers and computer software to convert, store, protect, process, transmit and securely retrieve information.

Today the term information technology includes many aspects of computing and technology and covers many fields. Information technology professionals perform a variety of duties that range from installing applications to designing complex computer networks and information databases. The duties of IT specialists may involve data management, networking, engineering computer hardware, database and software design, as well as the management and administration of the whole system. When computer and communication technologies are combined, the result is information technology, or “infotech”. Information technology describes any technology that helps to produce, manipulate, store, communicate and/or disseminate information.

Thus, Information Communication Technology (ICT) embraces all technologies for the communication of information. It includes any medium to record information (paper, pen, magnetic disc / tape, optical discs – CD / DVD, flash memory, etc.) and technology for broadcasting information – radio, television. It involves any technology for communicating through voice and sound or images – microphone, camera, loudspeaker, and telephone. At present it is apparently culminating to information communication with the help of Personal Computers (PCs) networked through the Internet, information technology that can transfer information using satellite system or intercontinental cables.

10. Revise the text and answer the questions:

1. What system does communication theory deal with? 2. When was the

mathematical theory for communication systems developed? 3. What are the distinguishing features of the theory? 4. What does modern communication theory stem from? 5. What was Wienner’s contribution into the development of communication theory? 6. What is IT? 7. What does it deal with? 8. What jobs are IT experts engaged in? 9. What do you understand by “infotech”? 9. What technologies does ICT include?

11. Memorize the following word combinations:

Communication theory; primarily; the source output; a voice wave form; a

sequence of binary digits; a set of sensors; a space probe; a high frequency radio link; a storage medium; distinguishing characteristics; a great emphasis on the theory of probability; a primary concern; encoder and decoder; in terms of; a given level of performance; to stem from; as well as; desirability; linear filter; additive noise; a prescribed delay; to have influence on subsequent research; implementation; support; management; particularly; software applications; computer hardware; to retrieve information securely; to cover many fields; perform a variety of duties; installing applications; to design complex computer networks and information databases; data management; networking; engineering computer hardware; database and software design; to disseminate information; to communicate through voice and sound or images; a loudspeaker; to network through the Internet.

12. Translate the following terms and word combinations into English:

Цифровая связь; технология организации дальней cвязи; методы

управления; беспроводная связь; дополнительная информация; передача в режиме реального времени; заданная задержка; установка прикладных программ; сигнал от аддитивных шумов; набор датчиков; отличительные свойства; высокочастотная радиосвязь; теория вероятности; беспорядочные процессы; охватывать многие области; автоматизированные информационные системы; последовательность двоичных цифр; управлять; размещать прикладные программы; видеосвязь; уровень пропускной способности.

13. Read the text and translate it into Russian: