Digital Communications 1

Fundamentals and Techniques

Safwan El Assad,Dominique Barba

• Publisher: Wiley-ISTE
• Year: 2020
• ISBN:
  9781119779773
• Edition: 1
• Topic: Computer Science
• Subtopic: Computer Engineering
• Index: Computer Science

It is a complete training in digital communications in the same book with all the aspects involved in such training: courses, tutorials with many typical problems targeted with detailed solutions, practical work concretely illustrating various aspects of technical implementation implemented. It breaks down into three parts. The Theory of information itself, which concerns both the sources of information and the channels of its transmission, taking into account the errors they introduce in the transmission of information and the means of protect by the use of appropriate coding methods. Then for the technical aspects of transmission, first the baseband transmission is presented with the important concept and fundamental technique of equalization. The performance evaluation in terms of probability of errors is systematically developed and detailed as well as the online codes used. Finally, the third part presents the Transmissions with digital modulation of carriers used in radio transmissions but also on electric cables. A second important aspect in learning a learner's knowledge and skills is this book. It concerns the "Directed Work" aspect of a training. This is an ordered set of 33 typical problems with detailed solutions covering the different parts of the course with practical work. Finally, the last aspect concerns the practical aspects in the proper sense of the term, an essential complement to training going as far as know-how. We propose here a set of 5 practical works.

Part 1
Theory of Information

Introduction to Part 1

Transmitting information between two entities, commonly referred to as the “source of information” for the first and the “recipient” or “user” for the second, assumes that this information is represented in a common and understandable form by both parties. It is also necessary that the amount of information exchanged does not exceed the transmission capacity of the channel. Lastly, it is desirable that the disturbances (modifications of all kinds) in the transmission channel have, if possible, little or, ideally, no effect on the information delivered to the recipient or user.

All this is studied, analyzed and treated in what is called the “theory of information”, the theoretical basis of different techniques of communication.

In a schematic way, the problems raised and treated by this are the following:

• – quantitative measurement of information;
• – representation of common information between sender and recipient: code;
• – source coding: adapting the source rate to the capacity of the transmission channel;
• – channel coding: protecting against transmission errors.

The block diagram of Figure I1.1 shows at what levels of the communications chain these problems are, both on the side of the emission of the information (transmitter) as on the side of the reception of the information (receiver).

Figure I1.1. General structure of a digital communications system and its problems. For a color version of this figure, see www.iste.co.uk/assad/digital1.zip

We have divided this first ...