The Local Wigner-Ville Distribution (LWVD) extends the Cohen's class time-frequency distributions (TFD) by the de nition of a kernel for each time-frequency point(local kernel). The subject of the paper is the determination of these local kernels for interference reduction. Starting from the simple idea of the local limitation of the Wigner-Ville TFD integral bounds, a method is presented to es...

This article demonstrates how time-frequency methods can be used in applications of image processing, such as monitoring, detecting inhomogeneities in textures and texture segmentation. A Pseudo Wigner Distribution (PWD) for 2D images free of aliasing and simultaneously increasing the spatial frequency support is defined through the use of a new analytic signal. In addition to that, cross-terms...

Digital modulation signals such as FSK are time-varying signals that can he represented in the time-frequency representation. The smooth lag-windowed Wigner-Ville distribution (SLWWVD) is proposed as a method to obtain accurate time-frequency representation of FSK signals used in HF (High Frequency) radio communications. Unlike existing time-frequency distributions such as the windowed Wigner-V...

BACKGROUND In this paper, we developed a novel algorithm to detect the valvular split between the aortic and pulmonary components in the second heart sound which is a valuable medical information. METHODS The algorithm is based on the Reassigned smoothed pseudo Wigner-Ville distribution which is a modified time-frequency distribution of the Wigner-Ville distribution. A preprocessing amplitude...

Under-determined blind source separation aims to separate N non-stationary sources from M (M<N) mixtures. Paper presents a time-frequency approach (TF) to under-determined blind source separation of N non-stationary sources from M mixtures(M<N).It is based on Wigner-Ville distribution and Khatri-Rao product. Improved method involves a two step approach which involves the estimation of the mixin...

BACKGROUND Analysis of heart rate variation (HRV) has become a popular noninvasive tool for assessing the activities of the autonomic nervous system (ANS). HRV analysis is based on the concept that fast fluctuations may specifically reflect changes of sympathetic and vagal activity. It shows that the structure generating the signal is not simply linear, but also involves nonlinear contributions...

This letter considers the problem of detecting and characterizing a target buried beneath a rough surface separating two homogeneous half spaces. The problem of detecting the target is tackled by analyzing the frequency-averaged Wigner–Ville function, the purpose of which is to filter out rough surface scattering. Characterization of the target is performed using the iterative solution derived ...

Cohen's class of Time-Frequency Distributions (CTFDs), which includes the spectrogram and the Wigner-Ville distribution, has significant potential for the analysis of non-stationnary signals. In order to efficiently compute long signals time-frequency representations, we propose fast algorithms using a recursive approach. First, we introduce a recursive algorithm dedicated to the spectrogram co...

Heart sounds and murmurs are timevarying signals that would best be analyzed using timefrequency analysis. Windowed Wigner-Ville distribution (WWVD) and smooth windowed Wigner-Vffle distribution (SWWVD) are used to obtain the timefrequency representation of the signal. Determination of parameter setting of WWVD and SWWVD will eliminate the cross-terms and improve time frequency representation. ...