As a practical example of "what the time-frequency analysis is all about"
we construct a puzzle:
let's make a signal constructed from known components - add them all
together - and see if one could guess what components we used! That can
serve as a metaphor for a big part of Signal Processing -
explain a signal through known functions. So, we'll use some canonical
shapes:
A - sine wave, C, D and E - sines modulated by Gauss (Gabor functions),
B - one-point discontinuoity (approximation of Dirac's delta).
Now let's see how some tools can help us solve this puzzle: