Time-frequency representation of seismic signals provides a source of information that is usually hidden in the Fourier spectrum. The short-time Fourier transform and the wavelet transform are the principal approaches to simultaneously decompose a signal into time and frequency components. Known limitations, such as trade-offs between time and frequency resolution, may be overcome by alternativ...

The aim of this paper is to present a new method for the estimation of the instantaneous frequency of a frequency modulated signal, corrupted by additive noise. Any time-frequency representation of an acquired signal is concentrated around the instantaneous frequency law of its useful component (the projection of the ridges of the time-frequency representation on the time-frequency plane) and r...

-Wavelet anatomization is globally appreciated up to the sixtieth part of an hour tools for timefrequency. It acquires an exceptional development based on Fourier fractionation and plays a consequential character in the signal processing remarkably in image compression. By analyzing the relations of the coefficients between every main block and the complete image, we can locate the catalogue lo...

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...

This paper presents a method for target recognition and classification in shallow water environment. It is based on timefrequency filtering matched to a free field reference target response. The decision strategy lies on the comparison of the reference and the filter output signal. The method is applied to an experimental data base containing target acoustic responses measured in a tank for typ...

A new method for extraction of general features in ECGs with atrial tachyarrhythmias is presented. The method is based on our recent method for atrial signal characterization which sequentially decomposes a timefrequency distribution into a set of parameters. In addition to rate and amplitude, the method tracks information on regularity, waveform, and structure of the atrial signal. The propose...

In this paper, a novel Matching Optimization Algorithm (MOA-algorithm) based on underdetermined blind source separation is proposed for non-orthogonal frequency hopping signal (that is, inner products are not always equal to zero in the same time-frequency point). Compared to traditional methods, the separation method is formulated as matching optimization. In our method, we accomplish the unde...

This paper presents a novel approach based on time-frequency distributions (TFDs) for separating signals received by a multiple antenna array. This approach provides a significant improvement in performance over the recently introduced spatial time-frequency distributions, specifically for signals with close time-frequency signatures. In this approach, spatial averaging of the time-frequency di...

Rainfall is one of the most significant parameters in a hydrological model. Several models have been developed to analyze and predict the rainfall forecast. In recent years, wavelet techniques have been widely applied to various water resources research because of their timefrequency representation. In this paper an attempt has been made to find an alternative method for rainfall prediction by ...