Multi-Carrier Technologies for Wireless Communication
MULTI-CARRIER TECHNOLOGIES FOR WIRELESS COMMUNICATION This page intentionally left blank MULTI-CARRIER TECHNOLOGIES FOR WIRELESS COMMUNICATION by Carl R. Nassar, B. Natarajan, Z. Wu D. Wiegandt, S. A. Zekavat Colorado State University S. Shattil Idris Communications KLUWER ACADEMIC PUBLISHERS NEW YORK, BOSTON, DORDRECHT, LONDON, MOSCOW eBook ISBN: 0-306-47308-9 Print ISBN: 0-792-37618-8 ©2002 Kluwer Academic Publishers New York, Boston, Dordrecht, London, Moscow All rights reserved No part of this eBook may be reproduced or transmitted in any form or by any means, electronic, mechanical, recording, or otherwise, without written consent from the Publisher Created in the United States of America Visit Kluwer Online at: http://www.kluweronline.com and Kluwer's eBookstore at: http://www.ebooks.kluweronline.com AUTHOR BIOGRAPHIES Carl R. Nassar received his Bachelor’s, Master’s and Ph.D. degrees all from McGill University, Montreal, Canada, in 1989, 1990, and 1997 respectively. Between 1991 and 1992, he worked as a design engineer at CAE Electronics. In 1997, upon completion of his doctorate, Carl accepted a position as assistant professor at McGill University. In the fall of 1997, he headed for the mountains of Colorado when he accepted an assistant professorship at Colorado State University. Since that time, Carl has founded the RAWCom (Research in Advanced Wireless Communications) laboratory at CSU. He has been working on the development of multi-carrier technologies for the wireless world (the topic of this book). He has authored numerous journal articles, conference proceedings, and is also the author of the textbook Telecommunications Demystified. Bala Natarajan received his B.E degree in Electrical and Electronics Engineering with distinction from Birla Institute of Technology and Science, Pilani, India in 1997. Since August 1997, he has been at the department of Electrical and Computer Engineering, Colorado State University, where he will complete his Ph.D. in the spring of 2002. His current research interests include multiple access techniques, estimation theory, multi-user detection and channel modeling. “I am extremely grateful to my parents for the sacrifices they have made and for imparting the values and morals that guide my life. I would like to express my gratitude and love to sister Bharathi and her wonderful family for their support and encouragement. Thanks to all the wonderful people in my lab who have shared their joy with me and helped me live in that spirit of joy. Thank you, Carl, for being a good friend and an understanding advisor, helping me grow academically as well as spiritually. Thank you God, for being with me, around me and in me.” – Bala Natarajan. Zhiqiang Wu received his B.S. in Wireless Telecommunication from Beijing University of Posts and Telecommunications in 1993, his M.S. in Computer Signal Processing from Peking University in 1996, and his Ph.D. at Colorado State University in Telecommunications in 2001. Between 1996 and 1998, Dr. Wu worked as a research engineer at the Software Center in China’s Academy for Telecommunication Technology, Beijing. He is co-author of the network management standard for DS-CDMA in China. “It is with great pleasure that I thank my dearest sister, Zhijin Wu, and my parents, Yuanqian Wu and Hong Xu, for their consistent and loving support.” – Zhiqiang Wu. David A. Wiegandt received his Bachelor of Science degree in Electrical Engineering from New Mexico State University in December 1999. Since that time, he has been pursuing a Ph.D. as a graduate research assistant in the RAWCom Laboratory of Colorado State University’s Department of Electrical and Computer Engineering. Research interests are centered around OFDM and WLAN enhancement. Work experience includes communication link design, channel estimation, and programmable signal processing with New Mexico State University and Sandia National Laboratories. “I would like to extend my sincere gratitude to my parents Karl and Elizabeth Wiegandt. Thank you for your guidance and your help, but most importantly, thank you for truly being my best friends. To my sister Jennifer, I love you. To Carl and my extended RAWCom family, a special thanks for sharing the tears and the laughs. It has genuinely been a pleasure.” – David Wiegandt S. Alireza Zekavat received his Bachelor’s and Master’s degrees from Shiraz University and Sharif University of Technology, respectively. He is currently a Ph.D. candidate at Colorado State University, Fort Collins, CO, U.S.A, and will be receiving his Ph.D. in the summer of 2002. His research interests are Wireless Communications, Statistical Modeling, Radar Systems and Neural Networks. “My professional career has benefited greatly from the guidance and support I received from the following wonderful people. Dr. H. Hashemi introduced me to the spirit of wireless communications and statistical modeling through the courses he taught. Dr. Carl R. Nassar supervised me during the challenges of a Ph.D. degree. He is a key part of my life and career. Dr. D. Lile’s support was also key to my successful academic career. Fatemeh and Maryam, my wife and daughter, prepared a lovely space in my house and in my heart. My father and mother provided unique and wonderful guidance and love. Without the support of all these people, throughout my life, I could not have achieved my current level of success. I love them all.” – S. Alireza Zekavat vi Arnold Alagar has over 15 years experience in communications and software engineering. Mr. Alagar co-founded Idris Communications, Inc., a research company dedicated to investigating the practical applications of quantum interferometry to communication systems. In addition, Mr. Alagar has over 12 years experience with the transfer of technology from R&D environments to practical use. At the San Diego Supercomputer Center, Mr. Alagar was involved with optimizing circuit simulation and design automation tools for use on Cray supercomputers. At BDM Federal and Lucent, Mr. Alagar gained extensive experience in the development and deployment of hardware and software systems used for communications in mission critical operations such as air traffic control and telecommunications. Steve Shattil holds an ME in EE from the University of Colorado, an MS in Physics from Colorado School of Mines, and a BS in Physics from Rensselaer Polytechnic Institute He serves as the co-founder, Chief Scientist and Patent Counsel at Idris Communications Inc. Prior to founding Idris, he led software development for aviation-related information systems. Mr. Shattil was a founder of Genesis Telecom and worked as a research scientist at the National Institute of Standards and Technology. He also led T Tauri Consulting, an optical-systems design firm whose clients included Ball Corporation and Ophir Corporation. vii This page intentionally left blank PREFACE This book is a journey to the cutting edge of research in the field of wireless telecommunications. Many other books take you on a similar but altogether different journeys: books on space-time coding, turbo-coding, OFDM, and the like. Our work takes the best of what is out there today, looks at where the wireless world wants to go, and then advances the best of the current work to reach those future goals. For this reason, my co-authors and I believe this book will take you for the ride of your life. In many ways, as we telecommunication engineers discover time and time again, the world of wireless telecomm is still in its infancy stages. In the early 1980’s we were humbled when it was shown that a simple merging of channel coding and modulation achieved large performance gains without bandwidth expansion (trellis coded modulation). A few years later, we were surprised (even resistant) when we learnt how a simple iterative algorithm could revolutionize the performance of channel coders (turbo coding). Then, a few years back, a simple procedure was developed for locating different coded bits on different antennas - it dramatically improved performance (space-time codes). When ideas that are, in hinsight, so simple, yet they radically improve the wireless world, we are forced to come to terms with a simple realization: we are still far from making maximal use of the wireless resource. In this book, we present you with yet another simple yet dramatic means of better exploiting the wireless medium. It is based on “smarter” signal processing. It involves the abandonment of time-based processing such the beloved equalizer structure and RAKE receiver. It replaces these old tools with new ones performing frequency based processing, breathing new life into old classics such as the FFT and IFFT. We are not the first to suggest the use of frequency domain processing. Far from it. Indeed, in today’s wireless world, OFDM and MC- CDMA, both based on frequency processing, find themselves in the limelight. However, no one, to the best of our knowledge, has gone as far as this book does in explaining and promoting the benefits of frequency-based processing. We demonstrate how TDMA, DS-CDMA, OFDM, and MC- CDMA can all share a common hardware platform based on a multi- carrier/frequency-based implementation. We show how the benefits of the [...]... direct result, probability of error performance is improved 11 12 2.2.3 MC-CDMA If OFDM is the flag bearer for the multicarrier nation, leading the charge toward a multi-carrier world, then MC-CDMA is its star athlete, generating a second surge of interest in multi-carrier technologies Before proceeding, a word of caution is in order The term MCCDMA, short for multi-carrier code division multiple access,... another This page intentionally left blank Chapter 2 OVERVIEW OF MULTI-CARRIER TECHNOLOGIES Past, Present, and Future 2.1 Introduction In the rapidly growing world of wireless telecommunications, a number of trends are gaining widespread popularity Among these is the explosion of interest in multi-carrier communications, and its application to wireless multiple-access In particular, there has been a great... CI/TDMA: Multi-Carrier Implementations of TDMA and the Demise of the Equalizer 2.6 CI/DS-CDMA: A Multi-Carrier Implementation of DS-CDMA and the Demise of the RAKE receiver 2.7 CI/OFDM: Increasing Performance and Throughput in OFDM and Eliminating the PAPR Problem 2.8 Summary 3 Overview of Multi-Carrier Technologies 5 6 6 8 12 16 16 17 20 21 23 24 29 33 37 High-Performance High-Capacity MC-CDMA for Future... significantly outperform its DS-CDMA counterpart 2.2.4 Recap In short, OFDM and its COFDM cousin are promising technologies delivering high-performance and reduced receiver complexities over the wireless link, all the while supporting very high data rates MC-CDMA is a powerful multi-carrier multiple access technology, capable of significantly outperforming its DS-CDMA counterpart For these reasons,... frontier of a multi-carrier revolution, and believe that multi-carrier technologies can be designed to support the needs of next-generation wireless and beyond, all the while providing a uniform hardware platform which enables true low-cost software radio 2.3 The Carrier Interferometry (CI) Approach 17 Using a technique referred to as the Carrier Interferometry (CI) Approach, the scope and power of multi-carrier. .. any wireless multiple-access 2 protocol Rooted in recent telecommunications history, CI can be understood as a giant leap in the arena of multi-carrier technology, building on the recent successes of OFDM and MC-CDMA 1.2 Unification The capacity, reliability, and versatility of communication systems continues to grow as people, businesses, and government organizations perceive a growing need for information... multiple access) to MC-CDMA to OFDM, while maintaining a common hardware platform In this chapter, we demonstrate how to advance existing multi-carrier technologies to bring the vision of a common hardware platform to immediate reality, bringing the future to life today In the opening section, we review the popular multi-carrier technologies of OFDM and MC-CDMA, explaining the reasons that underlie their... the reasons that underlie their growing importance In the sections that follow, we explain how a common multi-carrier platform can be designed for TDMA, DS-CDMA, MC-CDMA and OFDM We demonstrate how, in each and every scenario, a proposed multi-carrier platform is able to reduce complexity and outperform existing receiver structures in multipath fading channels, due to 6 better exploitation of the channel... proprietary transmission protocols and signalprocessing technologies This fragmentation impedes compatibility between different applications and systems, reduces bandwidth efficiency, increases interference, and limits the usefulness of wireless services Thus, there is an overwhelming need to improve and unify these technologies The idea of unifying wireless technologies is similar to some of the motives behind... this technology as a competitor for future 4G wireless systems These systems, expected to emerge by the year 2010, promise to at last deliver on the wireless Nirvana of anywhere, anytime, anything communications Should OFDM gain prominence in this arena, and companies such as Motorola are banking on just this scenario, then OFDM will become the technology of choice in most wireless links worldwide The . MULTI-CARRIER TECHNOLOGIES FOR WIRELESS COMMUNICATION This page intentionally left blank MULTI-CARRIER TECHNOLOGIES FOR WIRELESS COMMUNICATION. (Research in Advanced Wireless Communications) laboratory at CSU. He has been working on the development of multi-carrier technologies for the wireless world