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Saleh Faruque Radio Frequency Modulation Made Easy SPRINGER BRIEFS IN ELECTRICAL AND COMPUTER ENGINEERING Saleh Faruque Radio Frequency Modulation Made Easy 123 SpringerBriefs in Electrical and Computer Engineering More information about this series at http://www.springer.com/series/10059 Saleh Faruque Radio Frequency Modulation Made Easy 123 Saleh Faruque Department of Electrical Engineering University of North Dakota Grand Forks, ND USA ISSN 2191-8112 ISSN 2191-8120 (electronic) SpringerBriefs in Electrical and Computer Engineering ISBN 978-3-319-41200-9 ISBN 978-3-319-41202-3 (eBook) DOI 10.1007/978-3-319-41202-3 Library of Congress Control Number: 2016945147 © The Author(s) 2017 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. Printed on acid-free paper This Springer imprint is published by Springer Nature The registered company is Springer International Publishing AG Switzerland Preface By inventing the wireless transmitter or radio in 1897, the Italian physicist Tomaso Guglielmo Marconi added a new dimension to the world of communications. This enabled the transmission of the human voice through space without wires. For this epoch-making invention, this illustrious scientist was honored with the Nobel Prize for Physics in 1909. Even today, students of wireless or radio technology remember this distinguished physicist with reverence. A new era began in Radio Communications. The classical Marconi radio used a modulation technique known today as “Amplitude Modulation” or just AM. This led to the development of Frequency Modulation (FM), amplitude shift keying (ASK), phase shift keying (PSK), etc. Today, these technologies are extensively used in various wireless communication systems. These modulation techniques form an integral part of academic curricula today. This book presents a comprehensive overview of the various modulation tech- niques mentioned above. Numerous illustrations are used to bring students up-to-date in key concepts and underlying principles of various analog and digital modulation techniques. In particular, the following topics will be presented in this book: • Amplitude Modulation (AM) • Frequency Modulation (FM) • Bandwidth occupancy in AM and FM • Amplitude shift keying (ASK) • Frequency shift keying (FSK) • Phase shift keying (PSK) • N-ary coding and M-ary modulation • Bandwidth occupancy in ASK, FSK, and PSK This text has been primarily designed for electrical engineering students in the area of telecommunications. However, engineers and designers working in the area v vi Preface of wireless communications would also find this text useful. It is assumed that the student is familiar with the general theory of telecommunications. In closing, I would like to say a few words about how this book was conceived. It came out of my long industrial and academic career. During my teaching tenure at the University of North Dakota, I developed a number of graduate-level elective courses in the area of telecommunications that combine theory and practice. This book is a collection of my courseware and research activities in wireless communications. I am grateful to UND and the School for the Blind, North Dakota, for affording me this opportunity. This book would never have seen the light of day had UND and the State of North Dakota not provided me with the technology to do so. My heartfelt salute goes out to the dedicated developers of these technologies, who have enabled me and others visually impaired to work comfortably. I would like to thank my beloved wife, Yasmin, an English Literature buff and a writer herself, for being by my side throughout the writing of this book and for patiently proofreading it. My darling son, Shams, an electrical engineer himself, provided technical support in formulation and experimentation when I needed it. For this, he deserves my heartfelt thanks. Finally, thanks are also to my doctoral student Md. Maruf Ahamed who found time in his busy schedule to assist me with the simulations, illustrations, and the verification of equations. In spite of all this support, there may still be some errors in this book. I hope that my readers forgive me for them. I shall be amply rewarded if they still find this book useful. Grand Forks, USA Saleh Faruque May 2016 Contents 1 Introduction to Modulation .............................. 1 1.1 Background . 1 1.2 Modulation by Analog Signals . 3 1.2.1 AM, FM, and PM . 3 1.2.2 AM and FM Bandwidth at a Glance . 4 1.3 Modulation by Digital Signal . 5 1.3.1 Amplitude Shift Keying (ASK) Modulation . 5 1.3.2 Frequency Shift Keying (FSK) Modulation. 6 1.3.3 Phase Shift Keying (PSK) Modulation . 7 1.4 Bandwidth Occupancy in Digital Modulation . 7 1.4.1 Spectral Response of the Encoded Data . 8 1.4.2 Spectral Response of the Carrier Frequency Before Modulation. 9 1.4.3 ASK Bandwidth at a Glance. 10 1.4.4 FSK Bandwidth at a Glance . 11 1.4.5 BPSK Bandwidth at a Glance. 12 1.5 Conclusions . 14 References . 15 2 Amplitude Modulation (AM) ............................. 17 2.1 Introduction . 17 2.2 Amplitude Modulation . 19 2.3 AM Spectrum and Bandwidth . 20 2.3.1 Spectral Response of the Input Modulating Signal. 20 2.3.2 Spectral Response of the Carrier Frequency . 21 2.3.3 AM Spectrum and Bandwidth. 21 2.3.4 AM Response Due to Low and High Modulating Signals . 23 2.3.5 AM Demodulation . 24 2.3.6 Drawbacks in AM. 24 vii viii Contents 2.4 Double Sideband-Suppressed Carrier (DSBSC) . 25 2.4.1 DSBSC Modulation. 25 2.4.2 Generation of DSBSC Signal . 26 2.4.3 DSBSC Spectrum and Bandwidth . 27 2.4.4 DSBSC Drawbacks . 28 2.5 Single Sideband (SSB) Modulation . 29 2.5.1 Why SSB Modulation? . 29 2.5.2 Generation of SSB-Modulated Signal. 29 2.5.3 SSB Spectrum and Bandwidth . 30 2.6 Conclusions . 32 References . 32 3 Frequency Modulation (FM) ............................. 33 3.1 Introduction . 33 3.2 Frequency Modulation (FM) . 34 3.2.1 Background . 34 3.2.2 The Basic FM . 35 3.3 FM Spectrum and Bandwidth . 37 3.3.1 Spectral Response of the Input Modulating Signal. 37 3.3.2 Spectral Response of the Carrier Frequency . 38 3.3.3 FM Spectrum . 39 3.3.4 Carson’s Rule and FM Bandwidth. 40 3.3.5 Bessel Function and FM Bandwidth . 41 3.3.6 FM Bandwidth Dilemma . 42 3.4 Conclusions . 44 References . 44 4 Amplitude Shift Keying (ASK) ............................ 45 4.1 Introduction . 45 4.2 ASK Modulation . 46 4.3 ASK Demodulation . 48 4.4 ASK Bandwidth . 49 4.4.1 Spectral Response of the Encoded Data . 49 4.4.2 Spectral Response of the Carrier Frequency Before Modulation. 51 4.4.3 ASK Bandwidth at a Glance. 51 4.5 BER Performance . 53 4.6 Conclusions . 54 References . 55 5 Frequency Shift Keying (FSK) ............................ 57 5.1 Introduction . 57 5.2 Frequency Shift Keying (FSK) Modulation. 58 5.3 Frequency Shift Keying (FSK) Demodulation . 60 Contents ix 5.4 FSK Bandwidth. 61 5.4.1 Spectral Response of the Encoded Data . 61 5.4.2 Spectral Response of the Carrier Frequency Before Modulation. 63 5.4.3 FSK Bandwidth at a Glance . 63 5.5 BER Performance . 65 5.6 Conclusions . 67 References . 67 6 Phase Shift Keying (PSK) ............................... 69 6.1 Introduction . 69 6.2 Binary Phase Shift Keying (BPSK) . 70 6.2.1 BPSK Modulation . 70 6.2.2 BPSK Demodulation . 73 6.3 QPSK Modulation . 74 6.4 8PSK Modulation . 75 6.5 16PSK Modulation . 75 6.6 PSK Spectrum and Bandwidth . 77 6.6.1 Spectral Response of the Encoded Data . 77 6.6.2 Spectral Response of the Carrier Before Modulation . 79 6.6.3 BPSK Spectrum . 79 6.7 Conclusions . 82 References . 82 7 N-Ary Coded Modulation................................ 85 7.1 Introduction . 85 7.2 N-Ary Convolutional Coding and M-Ary Modulation . 86 7.2.1 Background . 86 7.2.2 Generation of Complementary Convolutional Codes . ..
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