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This paper is a contribution to the analysis of the statistical correlation of the wavelet packet coefficients resulting from the decomposition of a random process, stationary in the wide-sense, whose power spectral density (PSD) is bounded with support in ½Àp; pŠ. Consider two quadrature mirror filters (QMF) that depend on a parameter r, such that these(More)
—Shift invariance associated with good directional se-lectivity is important for the use of a wavelet transform (WT) in many fields of image processing. Generally, complex wavelet transforms, e.g., the double-tree complex WT (DTCWT), have these useful properties. In this paper, we propose the use of a recently introduced implementation of such a WT, namely,(More)
The damping of the harmonic oscillator is studied in the framework of the Lindblad theory for open quantum systems. A generalization of the fundamental constraints on quantum mechanical diffusion coefficients which appear in the master equation for the damped quantum oscillator is presented; the Schrödinger, Heisenberg and Weyl-Wigner-Moyal representations(More)
— WiMAX is a wireless technology which offers high data rate transmission in broadband. In this paper, the architecture of the WiMAX physical layer simulator is presented. The main blocks are implemented with the aid of the Matlab programming language and the bit error rate (BER) curves are presented in Rayleigh fading channel. I. INFORMATION Worldwide(More)
  • A Isar, D Isar, S Moga, J.-M Augustin, X Lurton, Fr
  • 2005
The SONAR images are perturbed by a multiplicative noise called speckle, due to the coherent nature of the scattering phenomenon. The use of speckle reduction filters is necessary to optimize the images exploitation procedures. This paper presents a new speckle reduction method in the wavelets domain using a novel Bayesian-based algorithm, which tends to(More)
The goal of this paper is to highlight the particularities of Worldwide Interoperability for Microwave Access (WiMAX) traffic from a long-range dependence perspective. The application presented in this paper consists in the estimation of the quality of base stations (BS) positioning in the architecture of a WiMAX network. Analysing the traffic of the(More)
In 1992 David Donoho has introduced the term de-noising. Despite its advantages, this method isn't used yet in communications. The goal of this paper is to adapt this method to the requirements of communications, especially for low SNR signals. Our contribution is a new threshold's value search method, that realizes the maximization of the signal to noise(More)
In the framework of the Lindblad theory for open quantum systems, we determine the degree of quantum decoherence of a harmonic oscillator interacting with a thermal bath. It is found that the system manifests a quantum de-coherence which is more and more significant in time. We also calculate the decoherence time and show that it has the same scale as the(More)