Date of Award

Fall 2002

Document Type

Thesis - Restricted

Degree Name

Master of Science (MS)

Department

Electrical and Computer Engineering

First Advisor

Yaz, Edwin E.

Second Advisor

Josse, Fabien

Third Advisor

Feng, Xin

Abstract

A chaotic dynamical system is a deterministic nonlinear system that has noise-like state trajectories. This kind of dynamical system has the property that it is super sensitive to initial conditions and parameter perturbations. These unique properties of chaotic systems provide the means of applying chaotic signals to encrypt messages that are sent over unsecured channels. Even if the signal is intercepted, the noise-like nature of the chaotic signal will make it impossible to understand. In this work, the basic concepts about chaotic dynamics and chaotic synchronization are introduced as the background of our work. The main part of this thesis focuses on the development of various novel chaotic secure communication schemes that are based on nonlinear state estimation techniques, which are extended Kalman filter and state dependent Riccati equation filters. In particular, chaotic versions of digital signal masking, speech signal masking, digital signal modulation and demodulation and code-division multiple access techniques are developed.

Share

COinS

Restricted Access Item

Having trouble?