Design and Analysis of Multicarrier Multicode Wavelet Packets Based CDMA Communication Systems with Multiuser Detection

As the demand for transmitting variable and high data rates rises, the need to develop more efficient wireless communication systems increases. In this dissertation, a new Wavelet Packets based Multicarrier Multicode Code Division Multiple Access (WPMC/MCD-CDMA) system, which combines the properties of wavelet packets with the concept of MC, MCD and CDMA, is proposed and analyzed. Another new wavelet packets based system, denoted as Wavelet Packets Multicarrier Multiuser Code Division Multiple Access (WP-MC/MU-CDMA) system, which combines the properties of wavelet packets with the concept of MC and CDMA, is proposed and analyzed. The WP-MC/MCD-CDMA can be used for multirate services using multicode schemes. In WP-MC/MU-CDMA system, a decorrelating suboptimum detector is used in the detection process. This will suppress the multiple access interference, support a higher number of users and relaxes the power control requirements. In our systems, wavelet packets functions are used as subcarrier instead of a sinusoidal function. Thus, the proposed systems have high immunity against interferences caused by multipath and multicarriers. The systems are evaluated in Nakagami slow fading channel, and their performance are investigated in terms of signalto-noise plus interference ratio, bit error rate and outage probability. Three diversity combiners, namely selective diversity, equal gain combining and maximal ratio combining are used at the receiver to improve the system performance. Results show that the new proposed systems are viable for future generation wireless systems. iii ACKNOWLEDGEMENTS I would like to express my thanks and sincere appreciation to my advisor, Dr. Okechukwu C. Ugweje, for his encouragement, support and guidance throughout the course of my doctoral research. I would like to extend my thanks to the Dissertation Committee members, Drs. Igor Tsukerman, Dale Mugler, George Giakos, Paul Lam and Malik Elbuluk for their review of the final manuscript and valuable suggestions. I enjoyed the teaching of Drs. Tsukerman and Mugler and I value the information I got in their courses. Besides the technical help and support, Dr. Elbuluk has always been available to give me advice and guidance. Special thanks go the faculty and staff of the Department for their support. Drs. Alex De Abreu, Department Chair and Robert Veillette, Graduate Policy Committee Chair, have been kind and supportive. The help I received from the Secretary of the Department, Mrs. Gay Boden cannot go without mentioning. I would like also to acknowledge the support I received from colleagues and friends inside and outside the university of Akron. Also, many thanks to my family and relatives for their support and encouragement, especially to my mother, brothers and sisters for their confidence in me and for being there when I needed them. I dedicate this dissertation to my late father Mahmoud Akho-Zahieh who has dedicated his life for the support of our family. His hard work, dedication and compassion will never be forgotten. I hope to posses a fraction of his role towards my family. iv TABLE OF CONTENTS Page LIST OF TABLES . xi LIST OF FIGURES . xii LIST OF ACRONYMS . xvi LIST OF SYMBOLS . xix CHAPTER