Synchronization and estimation of unknown constant parameters for Lorenz-type transmitter are studied under the assumption that one of the three state variables is not transmitted and that transmitter parameters are not known apriori. An adaptive algorithm is proposed to estimate both the state and system parameters. Since Lorenz system shows the property of sensitivity to initial conditions and evolves in different mode with parameter variation, an equivalent system is introduced. The adaptive observer is designed based on this equivalent system without any requirement on initial conditions of the observer. It is shown by Lyapunov arguments and persistent excitation analysis that exponential stability of state and parameter estimation is guaranteed. Simulation results are included to demonstrate properties of the algorithm. In a practical communication system, the received signals presented at the receiver part differ from those which were transmitted due to the effects of noise. The proposed synchronization scheme is robust with regard to external bounded disturbance. When an additive white gaussian noise (AWGN) channel model is considered, estimates of state and parameter converge except for small errors. The results show promise in either coherent detection or the message decoding in telecommunication systems.
| Identifer | oai:union.ndltd.org:ucf.edu/oai:stars.library.ucf.edu:etd-1032 |
| Date | 01 January 2004 |
| Creators | Jin, Yufang |
| Publisher | STARS |
| Source Sets | University of Central Florida |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Electronic Theses and Dissertations |
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