Chaos-Based Digital Communication Systems : Operating Principles, Analysis Methods, and Performance Evaluation

In the 1970's and 1980's, we saw phenomenal advancement in nonlinear sci­ ence, which had led to many important discoveries that greatly improve our understanding of the physical world. Among them, the discovery of chaos in deterministic systems is unarguably one of the most revolutionary scientific findings. We are now able to explain the apparent complexity and subtle or­ der exhibited by many physical systems under the unified framework of chaos theory. The past decade has seen heightened interest in the exploitation of chaos for useful applications in engineering systems. One application area that has attracted a great deal of attention is communications. Chaotic signals, by virtue of their wide band characteristic, are natural candidates for carrying information in a spread-spectrum communication environment. The use of chaotic signals in communications thus naturally inherits the advantages that are currently being offered by conventional spread-spectrum communication systems, such as robustness in multi path environments, resistance to jam­ ming, low probability of interception, etc. In addition, chaotic signals are easy to generate and hence offer a potentially low-cost solution to spread­ spectrum communications. Although many practical problems need to be solved before chaos-based communications can be realized in practice, the field has advanced rapidly during the past few years and it now reaches a point where abstract concepts from physics and mathematics have been fruitfully ported to techniques that allow information to be carried by chaotic signals.

This book addresses the application of chaos in communication systems. An emerging discipline, chaos-based communication has been an important research topic in the past two decades. This book focuses on important aspects of the system operation, analysis, and performance evaluation of selected chaos-based communication systems, e.g., chaos-shift-keying (CSK) and differential CSK (DCSK) systems. The book is written for graduate level readership.

The main emphases are analysis techniques and performance evaluations. Chaos-based communication systems are spread-spectrum systems, and hence should provide multiple access and are expected to possess anti-jamming capabilities. The performance of the chaos-based digital communication systems under multi-user environments is studied in detail. This book provides thorough evaluations of the anti-jamming capabilities of chaos-based digital communication systems under single-tone jammers and pulsed-noise jammers. A detailed analysis of the extent of mutual interference in the likely practical event that chaos-based systems and conventional systems operate in shared frequency bands is also given. Furthermore, some selected research topics are discussed, e.g., detection methods, multiple access techniques, etc.

Being research oriented, the book will find interest among researchers, professors, graduate students, technology developers, and R&D engineers in communications. In general, readers will benefit from the detailed exposition of analysis methods and the thorough evaluations of chaos-based systems. Specifically, researchers who are new to the field will quickly get acquainted with the necessary analytical techniques for studying chaos-based digital communication systems, while experienced researchers will find the many benchmark results useful for reference and further study.