Wireless Communications: Algorithmic Techniques

Digital radios have undergone an astonishing evolution in the last century. Born as a set of simple and power-hungry electrical and electromechanical devices for low data rate transmission of telegraph data in the Marconi age, they have transformed, thanks to substantial advances in electronic technology, into a set of small, reliable and sophisticated integrated devices supporting broadband multimedia communications. This, however, would not have been possible unless significant progress had been made in recent decades in the field of signal processing algorithms for baseband and passband signals. In fact, the core of any modern digital radio consists of a set of algorithms running over programmable electronic hardware. This book stems from the research and teaching activities of its co-authors in the field of algorithmic techniques for wireless communications. A huge body of technical literature has accumulated in the last four decades in this area, and an extensive coverage of all its important aspects in a single textbook is impossible. For this reason, we have selected a few important topics and, for ease of reading, organized them into two parts. Part I concerns digital modulation techniques, characterization and modeling of wireless channels, channel estimation, and channel equalization metrics and algorithms. Part II focuses on channel coding, coded modulation, and combined equalization and decoding. For each of these topics, we have tried to provide an advanced introduction, blending basic principles with advanced concepts and techniques which play an important role at the forefront of research in wireless communications. In addition, for each topic we have provided some historical notes, so that the reader can analyze it in the right perspective, understanding both its roots and its possible evolutionary paths. From the outset our main goal has been to produce a textbook for beginning graduate and senior students, who are expected to have some basic knowledge in the fields of Fourier transform techniques, probability theory, random processes, sampling theory, linear filtering, vector spaces, matrix algebra and linear transformations. Some information about more advanced concepts in these fields is provided in the appendices of the book, which, for this reason, we believe to be self-contained. This book can serve as a text in either one-semester or two-semester courses in digital communications and coding. A natural division is to cover Part I in the first semester and Part II in the second. An alternative one-semester course can cover a portion of the material of Part I (Chapters 1–4 and 6) and some basic material from Part II (Chapters 7–9). The writing of this book has required a substantial commitment. We owe much to all those people who volunteered to read parts of it, correct mistakes and provide suggestions for enriching its technical content and improving its clarity of presentation. In particular, we are grateful Francesco Montorsi, Fabio Gianaroli, Tommaso Foggi, Amina Piemontese, Nicolò Mazzali, Andrea Modenini and Alessandro Ugolini for their contributions. Our sincere thanks go also to the editorial staff of Wiley and, in particular, to Mark Hammond, Sarah Hinton, Jennifer Beal, and Susan Barclay, who have always supported us in the writing process. We do hope that the uncountable hours devoted to this book will bear fruit in stimulating interest in the study of modern techniques for wireless communications.