Time-Frequency Foundations of Communications: Concepts and Tools

Hitherto communication theory was based on two alternative methods of signal analysis. One is the description of the signal as a function of time; the other is Fourier analysis. Both are idealizations, as the first method operates with sharply defined instants of time, the second with infinite wave-trains of rigorously defined frequencies. But our everyday experiences?especially our auditory sensations?insist on a description in terms of both time and frequency.?