Date of Award

Summer 2003

Document Type

Thesis - Restricted

Degree Name

Master of Science (MS)


Electrical and Computer Engineering

First Advisor

Yaz, Edwin E.

Second Advisor

Feng, Xin

Third Advisor

Josse, Fabien J.


A chaotic dynamical system is a nonlinear dynamical system, which is deterministic (not random), whose orbit exhibits irregular behavior and never repeats itself Certain properties of chaotic systems are appealing for communications such as low power requirement, broadband spectra and noise-like appearance. Due to these properties, chaotic dynamic systems are very interesting for future secure communication applications. A typical chaotic communication scheme can be described as follows: when the message is modulated by a chaotic signal at the transmitter, it is necessary to have another similar chaotic system at the receiver to synchronize with the transmitter's chaotic system. Thus the original message can be reconstructed by demodulation. However, one important property of a chaotic system is the super sensitivity to initial conditions which is that two signals from the same chaotic system with slightly different initial conditions will diverge rapidly in time. This makes synchronization a very difficult and important issue in the chaotic secure communication applications. In this research, we will first study the chaotic signal generation process to be able to obtain a deep insight into the chaotic system behavior. Then we will study the Extended Kalman Filter, which is a nonlinear state estimator employed to synchronize the receiver and the transmitter. Finally, we will take an EKF-Based parameter estimation approach for demodulation in the secure chaotic communication.



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