Formulation of communication theory in the time-frequency plane - Practical aspects

The relation between the characteristics of a signal and the characteristics of its time-frequency representation is considered within the framework of communication theory. It is shown that for purposes of communication, only a portion of the signal representative of the entire message, which is designated the effective portion, need be considered. Measurements of the effective portion of the signal and the interpretation of signal epoch and frequency are then discussed. The Ville-Wigner time-frequency representation is shown to yield a complete characterization of the effective portion. The application of the Ville-Wigner representation to a practical problem is illustrated