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Identification Algébrique et Déterministe de Signaux et Systèmes à Temps Continu : Application à des Problèmes de Communication Numérique

Abstract : This thesis is concerned with the problem of signals and systems identification applied to digital communication. While
the majority of the existing methods are stochastic, we propose an algebraic and deterministic approach. Moreover, we
will treat signals and systems directly in continuous time, which enables us to explore the knowledge of their shape,
that may be hidden or forgotten by the sampling operation. Furthermore, the proposed techniques are simple and rapid,
what allows their on-line implementation.

Firstly, we consider the problem of correcting distortions in a power-line communication system, exploring its flatness
property. The inverse system obtained is then applied to another context, more specifically to the restoration of the
voice timbre in telephone networks.

Afterwards, the system identification problem is considered in the context of a new deterministic theory, based on
differential algebra and operational calculus. This theory gives rise to a new general algorithm for the input-output
identification of a rational system. The rapidness of estimation also allows the presentation of the local filtering
notion, which consists in representing a high dimension system by a time-varying low dimension model. This approach is
interesting since it permits the direct demodulation of the received signal, without the need of explicitly identifying
or equalizing the channel.

Finally, the demodulation of a continuous phase modulation signal is addressed in the light of the algebraic techniques
proposed. The solution consists in describing the received signal, at each symbol period, as a linear differential
equation (generally with time-varying coefficients), with coefficients that are functions of the current symbol.
Therefore, the symbol by symbol demodulation becomes immediate and particularly robust to noise.
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https://tel.archives-ouvertes.fr/tel-00084799
Contributor : Aline Neves Panazio <>
Submitted on : Monday, July 10, 2006 - 4:06:28 PM
Last modification on : Friday, March 27, 2020 - 2:34:31 AM
Long-term archiving on: : Tuesday, September 18, 2012 - 4:05:45 PM

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Aline Neves. Identification Algébrique et Déterministe de Signaux et Systèmes à Temps Continu : Application à des Problèmes de Communication Numérique. domain_stic.theo. Université René Descartes - Paris V, 2005. Français. ⟨tel-00084799⟩

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