High-gain observer for chaotic synchronization and secure communication

An information signal can be embedded in a transmitter which produces a chaotic signal, it is inviable to the observer who has no knowledge about the transmitter, but it can be recovered if the receiver is a replica of the chaotic transmitter. In this paper, a new aspect of the chaotic communication is introduced. A highgain observer at the receiver’s end replaces the conventional chaotic system. A single parameter is adjusted so that the receiver and transmitter can be synchronized. Three chaotic systems, Duffing equation, Van der Pol oscillator and Chua’s circuit, are provided to illustrate the effectiveness of the chaotic communication. Copyright # 2005 John Wiley & Sons, Ltd.