Secure communications of chaotic systems with robust performance via fuzzyobserver-based design

This paper presents a systematic design methodology for fuzzy observer-base d secure communications of chaotic systems with guaranteed robust performan ce. The Takagi-Sugeno fuzzy models are given to exactly represent chaotic s ystems. Then, the general fuzzy model of many well-known chaotic systems is constructed with only one premise variable in fuzzy rules and the same pre mise variable in the system output, Based on this general model, the fuzzy observer of chaotic system is straightforwardly given and leads the stabili ty condition to a linear-matrix inequality (LMI) problem. When taking the f uzzy observer-based design to applications on secure communications, the ro bust performance is presented by simultaneously considering the effects of parameter mismatch and external disturbances. Then, the error of the recove red message is stated in an H-infinity criterion. In addition, if the commu nication system is free of external disturbances, the asymptotical recoveri ng of the message is obtained in the same framework, The main results also hold for applications on chaotic synchronization Numerical simulations illu strate that this proposed scheme yields robust performance.