JOHN B. ANDERSON holds the Ericsson Chair in Digital Communications at Lund University, Sweden. He was formerly a professor at Rensselaer Polytechnic Institute. He is a Fellow of the IEEE and is a recipient of the Humboldt Research Prize and the IEEE Third Millennium Medal. His research and consulting practice concentrates on communication algorithms and bandwidth-efficient coding. ROLF JOHANNESSON is Professor of Information Theory at Lund University, Sweden, and a Fellow of the IEEE. He was awarded the honor of Professor, honoris causa, from the Institute for Information Transmission Problems, Russian Academy of Sciences. His research interests include information theory, error-correcting codes, and cryptography.

• Preface vii1. Introduction: First Ideas and Some History 11.1 What is communication? 21.2 Why digital communication? 61.3 Some history 81.4 A few remarks on intellectual history 271.5 Conclusions 28References 292. Mathematical Methods of Information Transmission: Why Sinusoids? 302.1 Linear, time-invariant (LTI) systems 312.2 On the importance of being sinusoidal 432.3 The Fourier transform 482.4 What is bandwidth? 582.5 Discrete-time systems 662.6 Conclusions 69References 70Problems 703. Information Sources: What is Out There to be Sent? 773.1 What is text? 783.2 What is speech? 813.3 What is music? 883.4 What is an image? 943.5 What is video? 983.6 Conclusion 102References 102Problems 1034. Transmission Methods: How is Information Sent? 1054.1 Communication channels 1054.2 Analog modulation 1174.3 Digital modulation 1274.4 FM stereo, television and a little about electronics 1394.5 Conclusions 146References 147Problems 1475. Information Theory and Coding: What did Shannon Promise? 1505.1 Information theory—a primer 1525.2 Methods of source coding 1795.3 Methods of channel coding 1895.4 Trellis coded modulation 1995.5 Conclusions 205References 206Problems 2076. Cryptology: FUBSWRORJB?? 2116.1 Fundamentals of cryptosystems 2116.2 Caesar and Vigenere ciphers 2156.3 The Vernam cipher and perfect secrecy 2196.4 Stream ciphers 2206.5 Block ciphers 2236.6 Cryptomachines during World War II 2246.7 Two-key cryptography 2286.8 Conclusions 239References 239Problems 2397. Communication Networks: Let's Get Connected 2417.1 An overview of information networks 2417.2 Circuit switching: The telephone net 2527.3 Mobile telephony 2607.4 The Internet 265References 275Appendix A: Complex Numbers 276Appendix B: Sinusoids and Circuit Theory 281Appendix C: Probability Theory: A Primer 297Index 306About the Authors