Entropy Based Information Measures in the Joint Time-Frequency Plane

Entropy measures applied to time-frequency signal representations have been found to be reliable indicators of various signal’s features. This paper gives an introduction to the time-frequency signal analysis, emphasizing the properties of time-frequency distributions that allow the application of entropy measures to quantify signals complexity. The paper includes an overview of the key properties of the time-frequency entropy measures, as well as possible applications of these measures as estimators of the signal information content or number of signal components. Entropy measures have been also used for quantification of the performance of different time-frequency distributions, leading to kernel design based on local or global entropy minimization.