On positivity of time-frequency distributions

On positivity of time-frequency distributions

On Separability, Positivity and Minimum Uncertainty in Time-frequency Energy Distributions

Gaussian signals play a very special role in classical time-frequency analysis because they are solutions of apparently unrelated problems such as minimum uncertainty or positivity and separability of Wigner-Ville distributions. We investigate here some of the logical connections which exist between these diierent features, and we discuss some examples and counterexamples of their extension to ...

Positivity of Time-frequency Distribution Functions

This paper deals with the question how various lInaturalll conditions posed on time-frequency distribution functions prevent them to be non-negative everywhere for all signals. The attention is mainly restricted to distribution functions that involve the signal bilinearly. This paper summarizes and extends results recently obtained; the emphasis is on a coherent presentation of these results, r...

Robust time-frequency distributions

Study of the additive Gaussian noise influence on time-frequency (TF) distributions is an important issue [Article 9.1]. However, in many practical applications, especially in communications, signals are disturbed by a kind of impulse noise. These noises are commonly modeled by heavy-tailed (long-tailed) probability density functions (pdfs) [6]. It is well known fact that the conventional TF di...

A note on "Positive time-frequency distributions"

—We discuss the performance of certain recently proposed positive time-frequency distribution functions with correct marginals. It turns out that for signals of the FM type, satisfactory results can only be obtained with a strongly signal dependent choice of the param eters in these distribution functions.