# Preface

## Who is this book for?

This book provides a framework for understanding and evaluating the key design topics and choices involved in developing a data communications link.

It has been devised specifically to serve as a first stage text for undergraduate students (probably in their second year of study), such that they are fully equipped to study the more theoretical, statistical aspects of digital communications in later years, and will do so fully conversant with the context in which this analysis and rigour will be applied.

By bringing to the fore the design choices facing communications engineers, within an intuitive framework, the book also fulfils the role of a Getting Started plus Frequently Asked Questions manual in digital communications for practising engineers and managers. It will allow them to home in rapidly on the design parameters that are pertinent to their particular application and specification, and so better focus engineering resource within their organizations.

## What previous knowledge is required?

Readers of the book are expected to have a basic understanding of the frequency content of simple waveforms (Fourier Series expansions) and hence appreciate the concepts of bandwidth, filtering and so on.

In addition, the mathematics of integration, differentiation and trigonometry are assumed, but not relied on for understanding of the text. For those who are a bit rusty in these areas, a short review of Fourier series and relevant trigonometrical relationships is included in Chapter 1.

All other material is developed from an intuitive or first principles approach.

## How does the material in this book differ from other digital communications texts?

Most, if not all, competing student texts aim to cover the full subject matter over all years of a degree programme. As a consequence, the subject matter is predominately driven from a mathematical description of modulation type and performance, in contrast to the application and intuitive approach of this text.

The subject material in this book is a carefully selected range of topics that give the reader a structured overview of the digital communications arena, with emphasis on modem design, performance trade-offs, key limiting factors, and practical issues in implementation over real-world channels.

The book provides a layered framework in which the reader can quickly identify those design aspects relevant to his or her application and then follow the hyperlinks, or reference list provided, in order to obtain more specific information.

## Where has the material originated?

The material within the book has been developed and refined over ten years of lecturing on digital communications to second and third year undergraduates and Masters level students at Bristol University in England, in a series of focused courses to engineers and managers run by Oxford University, and on site with companies such as Hewlett-Packard and Philips.

Experience has repeatedly shown that practising engineers who have pursued an undergraduate or post-graduate communications course in the past welcome the applications-driven and context-driven structure of this book, serving as both a reminder of the key design issues and a pooling of the basic design information and criteria from which to structure a more detailed research or design programme.

## About the Author

Andy Bateman was formerly a Professor of Communications and Signal Processing at the University of Bristol, England. Aged 39, he has been involved in the research and design of digital communications systems for the past 16 years, working with companies such as Motorola, Nokia, Ericsson, AT&T and Hewlett-Packard to develop state-of-the-art data communications equipment. In 1995 he co-founded a company – Wireless Systems International Ltd – which specializes in providing equipment and design/consultancy in all aspects of wireless digital communications, with clients ranging from small and large telecommunications manufacturers to operators and end users. He can be contacted on email at: ab@wsi.co.uk

As a regular invited lecturer on the subject of digital communications design around the world, and with the challenging task of introducing second year undergraduates at Bristol to the vast topic of modern communications, he has developed a very intuitive means of presenting the often complex material so that the principles are easily grasped. This style makes the book very readable as both an excellent basic reference and introductory student text.

He is also author of the book Digital Signal Processing Design (Bateman and Yates (1989)) which is a practical guide to DSP algorithms and applications.

## Information for instructors/trainers

Files containing the figures from this book in Portable Document (pdf) format for use as transparencies will be made available for adopting lecturers or trainers. Please contact your local Addison Wesley Longman representative for information.

If you intend to network this product within your institution or company, please contact the following for further information:

Interactive Learning Europe
124 Cambridge Science Park
Milton Road
Cambridge
CB4 4ZS

Tel +44 (0)1223 425558 x 787
Fax +44 (0)1223 425349
Email sean.massey@awl.co.uk
Web www.awl-ile.com

Interactive Learning Europe specializes in software to facilitate interactive learning in Higher and Further Education, with an emphasis on software that can be used both professionally and by students.

## What do you think about this book?

If you have any feedback on either the book or CD please contact us at: engineering.feedback@awl.co.uk or visit the book's homepage at: http://www.awl-he.com/engineering/bateman.html. Alternatively click on the Updates & Feedback button from any page within the electronic version.

## Acknowledgements

I would like to express my thanks to Anna Faherty and Dylan Reisenberger at Addison Wesley Longman for their enthusiasm and professional approach in the preparation of this book, and Mike Smith for his magic with the JavaScript.

I would also like to thank my two sons, Callum (8) and Jamie (6), for letting me have time on my computer; my wife Jacqui ( ) for her encouragement and patience throughout and for her help with the composition of the CD’s title music. This book is dedicated to them and to my wider family spread throughout the world.

### Publisher’s Acknowledgements

The publishers are grateful to the following for permission to reproduce material featured in the book and on the CD: to Professor David Bull, Centre for Communications Research, University of Bristol, for images showing intelligent source coding in Chapter 7; to Motorola Limited for Semiconductor Technical Data sheets featured in in-depth sections in Chapters 5 amd 7; to Wireless Systems International Limited for images of the output of a cartesian loop amplifier with TETRA modulation input, the implementation of a CALLUM transmitter, the image of the feedforward amplifier and the image of its output, and the plot entitled X-RAY Power Grid, featured in Chapter 4. We are grateful to Corel for permission to feature certain clipart in artwork in this product. The images in the electronic product are only to be used for viewing purposes and may not be resaved or redistributed. Title page incorporating photograph, copyright Photodisc.

### Trademark Notice

Internet Explorer and Windows are trademarks of Microsoft Corporation.
Netscape, Netscape Navigator, Netscape Communicator and the Netscape logos are trademarks of Netscape Communications Corporation. Netscape Communications Corporation has not authorized, sponsored, endorsed or approved this publication and is not responsible for its content.
Macintosh is a trademark of Apple Computer, Inc.
MATLAB is a trademark of The Mathworks, Inc.
OAK DSP core is a registered trademark of LSI Logic Corporation.
TMS 320C6X/TMS320C6201 series are trademarks of Texas Instruments.
DCS1800 is a trademark of Digital Communications.