Let first remind on Dirichlet conditions:
In mathematics, the Dirichlet conditions are sufficient conditions for a real-valued, periodic function f to be equal to the sum of its Fourier series at each point where f is continuous. Moreover, the behavior of the Fourier series at points of discontinuity is determined as well (it is the midpoint of the values of the discontinuity). These conditions are named after Peter Gustav Lejeune Dirichlet.
The conditions are:
f must be absolutely integrable over a period.
f must have a finite number of extrema in any given bounded interval, i.e. there must be a finite number of maxima and minima in the interval.
f must have a finite number of discontinuities in any given bounded interval, however the discontinuity cannot be infinite.
To be able to represent periodic function using Fourier series (or nonperiodic function using Fourier transform), it must meet conditions above. My question is, are these conditions always met for signals which can be generated in practice?
