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...

We show that a correct use of the Wigner Distribution (WD) for time-frequency signal analysis requires use of the analytic signal. This version, often referred to as the Wigner-Ville Distribution (WVD), is straightforward to compute, does not exhibit any aliasing problem, and introduces no frequency artifacts. The problems introduced by the use of the Wigner Distribution with a real signal are ...

Using ESM, RWR and ARM missiles pose significant limitations to the performance of the radar systems in new battles. In these wars, MTI radars are commonly used with high Power to achieve long ranges, therefore they are easily detectable by the enemy EW receivers, and so they lose their effectiveness. In addition to having the ability of anti-Jamming and good ECCM, the radar systems should to u...

The 2D Quaternionic Fourier Transform (QFT), applied to a real 2D image, produces an invertible quaternionic spectrum. If we conserve uniquely the first quadrant of this spectrum, it is possible, after inverse transformation, to obtain, not the original image, but a 2D quaternion image, which generalize in 2D the classical notion of 1D analytical image. From this quaternion image, we compute th...

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...

The paper introduces a new kernel for the design of a high resolution time–frequency distribution (TFD). We show that this distribution can solve problems that the Wigner–Ville distribution (WVD) or the spectrogram cannot. In particular, the proposed distribution can resolve two close signals in the time–frequency domain that the two other distributions cannot. Moreover, we show that the propos...

This correspondence presents an iterative instantaneous frequency (IF) estimation scheme in which successive IF estimates are obtained from the peak of the cross Wigner-Ville distribution (XWVD) using a reference signal synthesized from an initial IF estimate. Theoretical and practical aspects of performance are discussed, and compared with other methods.