Optimum Spreading Sequences for Asynchronous CDMA System Based on Nonlinear Dynamical and Ergodic Theories
This chapter presents a tutorial and overview of the interplay among nonlinear dynamical system theory, ergodic theory, and the design and analysis of spreading sequences for CDMA communication systems. We first address some motivational factors in information theory, communication theory, and communication systems to chaotic communication systems. Then we consider some basic issues in CDMA communication system. Next we summarize some properties of nonlinear dynamical system and ergodic theories needed for this study. Some history and details on the design and analysis of optimum chaotic asynchronous and chip-synchronous spreading sequences for CDMA systems are given. These optimum spreading sequences allow about 15% more users than random white sequences/Gold codes in an asynchronous system and 73% more users in a chip-synchronous system. Comparisons of performance of these system under ideal and practical conditions are also made. Finally, some brief conclusions are given.
KeywordsOptimal Sequence CDMA System Spreading Sequence Chaotic Dynamical System Rician Fading Channel
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