https://sam.ensam.eu:443 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Fri, 10 Jul 2026 10:37:32 GMT 2026-07-10T10:37:32Z http://hdl.handle.net/10985/8916 Relationships between Psi_B energy operator and some time-frequency representations; Relations entre Psi_B et quelques représentations temps-fréquence BOUDRAA, Abdel-Ouahab Psi_B operator is an energy operator that measures the interactions between two complex signals. In this letter, new properties of Psi_B operator are presented. Connections between Psi_B operator and some time-frequency representations (cross ambiguity function, short-time Fourier transform, Zak transform, and Gabor coefficients) are established. Link between Psi_B operator of two input signals and their cross-spectrum is also derived. For two equal input signals, we find that Fourier transform of Psi_B operator is proportional to the second derivative of the ambiguity function. The established links show the ability of Psi_B operator to analyze non stationary signals. A numerical example is provided for illustrating how to estimate the second order moment, of a FM signal, using Psi_B operator. We compare the result to the moment given by the Wigner-Ville distribution Fri, 01 Jan 2010 00:00:00 GMT http://hdl.handle.net/10985/8916 2010-01-01T00:00:00Z BOUDRAA, Abdel-Ouahab Psi_B operator is an energy operator that measures the interactions between two complex signals. In this letter, new properties of Psi_B operator are presented. Connections between Psi_B operator and some time-frequency representations (cross ambiguity function, short-time Fourier transform, Zak transform, and Gabor coefficients) are established. Link between Psi_B operator of two input signals and their cross-spectrum is also derived. For two equal input signals, we find that Fourier transform of Psi_B operator is proportional to the second derivative of the ambiguity function. The established links show the ability of Psi_B operator to analyze non stationary signals. A numerical example is provided for illustrating how to estimate the second order moment, of a FM signal, using Psi_B operator. We compare the result to the moment given by the Wigner-Ville distribution http://hdl.handle.net/10985/8857 A New class of multi-dimensional Teager Kaiser and higher order operators based on directional derivatives; Une nouvelle classe d'opérateurs de Teager-Kaiser multidimensionnels basée sur les dérivées directionnelles d'ordre supérieur SALZENSTEIN, Fabien; BOUDRAA, Abdel-Ouahab; CHONAVEL, Thierry This work aims at introducing some energy operators linked to Teager-Kaiser energy operator and its associated higher order versions and expand them to multidimensional signals. These operators are very useful for analyzing oscillatory signals with time-varying amplitude and frequency (AM-FM). We prove that gradient tensors combined with Kronecker powers allow to express these operators by directional derivatives along any n-D vector. In particular, we show that the construction of a large class of non linear operators for AM-FM multidimensional signal demodulation is possible. Also, a new scalar function using the directional derivative along a vector giving the ”sign” of the frequency components is introduced. An application of this model to local n-D AM-FM signal is presented and related demodulation error rates estimates. To show the effectiveness and the robustness of our method in term of envelope and frequency components extraction, results obtained on synthetic and real data are compared to multi-dimensional energy separation algorithm and to our recently introduced n-D operator. Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/8857 2013-01-01T00:00:00Z SALZENSTEIN, Fabien BOUDRAA, Abdel-Ouahab CHONAVEL, Thierry This work aims at introducing some energy operators linked to Teager-Kaiser energy operator and its associated higher order versions and expand them to multidimensional signals. These operators are very useful for analyzing oscillatory signals with time-varying amplitude and frequency (AM-FM). We prove that gradient tensors combined with Kronecker powers allow to express these operators by directional derivatives along any n-D vector. In particular, we show that the construction of a large class of non linear operators for AM-FM multidimensional signal demodulation is possible. Also, a new scalar function using the directional derivative along a vector giving the ”sign” of the frequency components is introduced. An application of this model to local n-D AM-FM signal is presented and related demodulation error rates estimates. To show the effectiveness and the robustness of our method in term of envelope and frequency components extraction, results obtained on synthetic and real data are compared to multi-dimensional energy separation algorithm and to our recently introduced n-D operator. http://hdl.handle.net/10985/8856 On signals compression by EMD; Codage des signaux par EMD KHALDI, Kais; BOUDRAA, Abdel-Ouahab In this letter a new signals coding framework based on the Empirical Mode Decomposition (EMD) is introduced. The EMD breaks down any signal into a reduced number of oscillating components called Intrinsic Modes Decomposition (IMFs). Based on IMF properties, different coding strategies are presented. No assumptions concerning the linearity or the stationarity are made about the signal to be coded. Results obtained on ECG signals are presented and compared to those of wavelets coding. Sun, 01 Jan 2012 00:00:00 GMT http://hdl.handle.net/10985/8856 2012-01-01T00:00:00Z KHALDI, Kais BOUDRAA, Abdel-Ouahab In this letter a new signals coding framework based on the Empirical Mode Decomposition (EMD) is introduced. The EMD breaks down any signal into a reduced number of oscillating components called Intrinsic Modes Decomposition (IMFs). Based on IMF properties, different coding strategies are presented. No assumptions concerning the linearity or the stationarity are made about the signal to be coded. Results obtained on ECG signals are presented and compared to those of wavelets coding. http://hdl.handle.net/10985/8919 Analysis of multicomponent LFM signals by Teager-Huang-Hough Transform; Analyse des signaux multicomposante à modulation de fréquence linéaire par la transformation de Teager-Huang-Hough BOUCHIKHI, Abdelkhalek; BOUDRAA, Abdel-Ouahab; CEXUS, Jean-Christophe; CHONAVEL, Thierry A novel detection approach of linear FM (LFM) signals, with single or multiple components, in the time-frequency plane of Teager-Huang (TH) transform is presented. The detection scheme that combines TH transform and Hough transform is referred to as Teager-Huang-Hough (THH) transform. The input signal is mapped into the time-frequency plane by using TH transform followed by the application of Hough transform to recognize time-frequency components. LFM components are detected and their parameters are estimated from peaks and their locations in the Hough space. Advantages of THH transform over Hough transform of Wigner-Ville distribution (WVD) are: 1) cross-terms free detection and estimation, and 2) good time and frequency resolutions. No assumptions are made about the number of components of the LFM signals and their models. THH transform is illustrated on multicomponent LFM signals in free and noisy environments and the results compared with WVD-Hough and pseudo-WVD-Hough transforms. Wed, 01 Jan 2014 00:00:00 GMT http://hdl.handle.net/10985/8919 2014-01-01T00:00:00Z BOUCHIKHI, Abdelkhalek BOUDRAA, Abdel-Ouahab CEXUS, Jean-Christophe CHONAVEL, Thierry A novel detection approach of linear FM (LFM) signals, with single or multiple components, in the time-frequency plane of Teager-Huang (TH) transform is presented. The detection scheme that combines TH transform and Hough transform is referred to as Teager-Huang-Hough (THH) transform. The input signal is mapped into the time-frequency plane by using TH transform followed by the application of Hough transform to recognize time-frequency components. LFM components are detected and their parameters are estimated from peaks and their locations in the Hough space. Advantages of THH transform over Hough transform of Wigner-Ville distribution (WVD) are: 1) cross-terms free detection and estimation, and 2) good time and frequency resolutions. No assumptions are made about the number of components of the LFM signals and their models. THH transform is illustrated on multicomponent LFM signals in free and noisy environments and the results compared with WVD-Hough and pseudo-WVD-Hough transforms. http://hdl.handle.net/10985/8681 Image source detection for geoacoustic inversion by Teager-Kaiser energy operator DRIRA, Achraf; GUILLON, Laurent; BOUDRAA, Abdel-Ouahab This letter presents an improvement of the image source method (ISM) for geoacoustic inversion. The new algorithm is based on the Teager-Kaiser Energy Operator which ampli es the discontinuities in signals while the soft transitions are reduced. This property is exploited for accurate detection of time arrivals and thus for location of the image sources. The e ectiveness of the method is shown on both synthetic and real data and the inversion results are, overall, in good agreement with ground truth and other inversion results with a signi cant reduction of computation time. Wed, 01 Jan 2014 00:00:00 GMT http://hdl.handle.net/10985/8681 2014-01-01T00:00:00Z DRIRA, Achraf GUILLON, Laurent BOUDRAA, Abdel-Ouahab This letter presents an improvement of the image source method (ISM) for geoacoustic inversion. The new algorithm is based on the Teager-Kaiser Energy Operator which ampli es the discontinuities in signals while the soft transitions are reduced. This property is exploited for accurate detection of time arrivals and thus for location of the image sources. The e ectiveness of the method is shown on both synthetic and real data and the inversion results are, overall, in good agreement with ground truth and other inversion results with a signi cant reduction of computation time. http://hdl.handle.net/10985/8859 Instantaneous frequency estimation of FM signals by Psi_B-energy operator; Estimation de la fréquence instantanée des signaux FM par opérateur d'énergie Psi_B BOUDRAA, Abdel-Ouahab Psi_B energy operator is an extension of the cross Teager-Kaiser energy operator which is an non-linear energy tracking operator to deal with complex signals and its usefulness for non-stationary signals analysis has been demonstrated. In this letter two new properties of Psi_B are established. The first property is the link between Psi_B and the dynamic signal which is a generalization of the Instantaneous Frequency (IF). The second property obtained for frequency modulated signals is a simple way to estimate the IF. These properties confirm the interest of Psi_B operator to track the non-stationary of a signal. Results of IF estimation in noisy environment of a non-linear FM signal are presented and comparison to Wigner-Ville distribution and Hilbert transform-based method is provided. Sat, 01 Jan 2011 00:00:00 GMT http://hdl.handle.net/10985/8859 2011-01-01T00:00:00Z BOUDRAA, Abdel-Ouahab Psi_B energy operator is an extension of the cross Teager-Kaiser energy operator which is an non-linear energy tracking operator to deal with complex signals and its usefulness for non-stationary signals analysis has been demonstrated. In this letter two new properties of Psi_B are established. The first property is the link between Psi_B and the dynamic signal which is a generalization of the Instantaneous Frequency (IF). The second property obtained for frequency modulated signals is a simple way to estimate the IF. These properties confirm the interest of Psi_B operator to track the non-stationary of a signal. Results of IF estimation in noisy environment of a non-linear FM signal are presented and comparison to Wigner-Ville distribution and Hilbert transform-based method is provided. http://hdl.handle.net/10985/9051 Débruitage fréquentiel de signaux par EMD KOMATY, Ali; DARE-EMZIVAT, Delphine; BOUDRAA, Abdel-Ouahab Dans cet article, nous proposons un nouveau schéma de débruitage des signaux basé sur la décomposition modale empirique associée à une analyse fréquentielle. Le principe de l’approche consiste à seuiller les modes extraits du signal bruité dans le domaine fréquentiel et non dans le domaine temporel comme c’est le cas du débruitage classique. Chaque mode est décomposé en blocs de même taille et le contenu fréquentiel de chacun d’eux est analysé. Le critère de sélection d’un bloc dit "pertinent" repose sur deux seuils, l’un énergétique, le second fréquentiel, seuils obtenus à l’issue d’une phase d’apprentissage. Le signal est alors reconstruit en utilisant tous les modes seuillés. Les performances du nouveau débruitage sont illustrés sur des signaux synthétiques et réels et les résultats comparés à ceux de la littérature. Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/9051 2013-01-01T00:00:00Z KOMATY, Ali DARE-EMZIVAT, Delphine BOUDRAA, Abdel-Ouahab Dans cet article, nous proposons un nouveau schéma de débruitage des signaux basé sur la décomposition modale empirique associée à une analyse fréquentielle. Le principe de l’approche consiste à seuiller les modes extraits du signal bruité dans le domaine fréquentiel et non dans le domaine temporel comme c’est le cas du débruitage classique. Chaque mode est décomposé en blocs de même taille et le contenu fréquentiel de chacun d’eux est analysé. Le critère de sélection d’un bloc dit "pertinent" repose sur deux seuils, l’un énergétique, le second fréquentiel, seuils obtenus à l’issue d’une phase d’apprentissage. Le signal est alors reconstruit en utilisant tous les modes seuillés. Les performances du nouveau débruitage sont illustrés sur des signaux synthétiques et réels et les résultats comparés à ceux de la littérature. http://hdl.handle.net/10985/10293 On signal denoising by EMD in the frequency domain BAY-AHMED, Hadj-Ahmed; KOMATY, Ali; DARE-EMZIVAT, Delphine; BOUDRAA, Abdel-Ouahab In this work a new denoising scheme based on the empirical mode decomposition associated with a frequency analysis is introduced. Compared to classical approaches where the extracted modes are thresholded in time domain, in the proposed strategy the thresholding is done in the frequency domain. Each mode is divided into blocks of equal length where the frequency content of each one is analyzed. Relevant modes are identified using an energy and a frequency thresholds obtained by training. The denoised signal is obtained by the superposition of the thresholded modes. The effectiveness of the proposed scheme is illustrated on synthetic and real signals and the results compared to those of methods reported recently. Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/10985/10293 2015-01-01T00:00:00Z BAY-AHMED, Hadj-Ahmed KOMATY, Ali DARE-EMZIVAT, Delphine BOUDRAA, Abdel-Ouahab In this work a new denoising scheme based on the empirical mode decomposition associated with a frequency analysis is introduced. Compared to classical approaches where the extracted modes are thresholded in time domain, in the proposed strategy the thresholding is done in the frequency domain. Each mode is divided into blocks of equal length where the frequency content of each one is analyzed. Relevant modes are identified using an energy and a frequency thresholds obtained by training. The denoised signal is obtained by the superposition of the thresholded modes. The effectiveness of the proposed scheme is illustrated on synthetic and real signals and the results compared to those of methods reported recently. http://hdl.handle.net/10985/10092 Estimation des paramètres d'un processus Symétrique Alpha Stable (S-alpha-Stable) à partir de ses modes empiriques KOMATY, Ali; BOUDRAA, Abdel-Ouahab; DARE-EMZIVAT, Delphine Dans ce travail nous nous intéressons au problème d’estimation des paramètres d’un processus alpha stable symétrique à partir de ses modes empiriques extraits par la décomposition modale empirique multivariée (MEMD). Nous exploitons le fait que le caractère impulsif du bruit est mieux préservé par ses premiers modes empiriques pour estimer son exposant caractéristique ainsi que son facteur d’échelle. Nous montrons que les paramètres du processus sont mieux estimés à partir de ses modes empiriques que du processus lui-même. Des résultats d’estimation des paramères utilisant le MEMD sont présentés et comparés à ceux des estimateurs basés sur les quantiles et la fonction caractéristique empirique. Thu, 01 Jan 2015 00:00:00 GMT http://hdl.handle.net/10985/10092 2015-01-01T00:00:00Z KOMATY, Ali BOUDRAA, Abdel-Ouahab DARE-EMZIVAT, Delphine Dans ce travail nous nous intéressons au problème d’estimation des paramètres d’un processus alpha stable symétrique à partir de ses modes empiriques extraits par la décomposition modale empirique multivariée (MEMD). Nous exploitons le fait que le caractère impulsif du bruit est mieux préservé par ses premiers modes empiriques pour estimer son exposant caractéristique ainsi que son facteur d’échelle. Nous montrons que les paramètres du processus sont mieux estimés à partir de ses modes empiriques que du processus lui-même. Des résultats d’estimation des paramères utilisant le MEMD sont présentés et comparés à ceux des estimateurs basés sur les quantiles et la fonction caractéristique empirique. http://hdl.handle.net/10985/8922 EMD-Based Filtering Using Similarity Measure Between Probability Density Functions of IMFs KOMATY, Ali; BOUDRAA, Abdel-Ouahab; AUGIER, Benoit; DARE-EMZIVAT, Delphine This paper introduces a new signal-filtering which combines the empirical mode decomposition (EMD) and a similarity measure. A noisy signal is adaptively broken down into oscillatory components called intrinsic mode functions (IMFs) by EMD followed by an estimation of the probability density function (pdf) of each extracted mode. The key idea of this paper is to make use of partial reconstruction, the relevant modes being selected on the basis of a striking similarity between the pdf of the input signal and that of each mode. Different similarity measures are investigated and compared. The obtained results, on simulated and real signals, show the effectiveness of the pdf-based filtering strategy for removing both white Gaussian and colored noises and demonstrate its superior performance over partial reconstruction approaches reported in the literature. Wed, 01 Jan 2014 00:00:00 GMT http://hdl.handle.net/10985/8922 2014-01-01T00:00:00Z KOMATY, Ali BOUDRAA, Abdel-Ouahab AUGIER, Benoit DARE-EMZIVAT, Delphine This paper introduces a new signal-filtering which combines the empirical mode decomposition (EMD) and a similarity measure. A noisy signal is adaptively broken down into oscillatory components called intrinsic mode functions (IMFs) by EMD followed by an estimation of the probability density function (pdf) of each extracted mode. The key idea of this paper is to make use of partial reconstruction, the relevant modes being selected on the basis of a striking similarity between the pdf of the input signal and that of each mode. Different similarity measures are investigated and compared. The obtained results, on simulated and real signals, show the effectiveness of the pdf-based filtering strategy for removing both white Gaussian and colored noises and demonstrate its superior performance over partial reconstruction approaches reported in the literature.