imagine this signals in the time-domain:
green: without a reset; blue: with a reset after each 1000 samples
Amplitude-Spectrum of the signals from picture 1 in semilogarithmic plot (y-axis is log10, x-axis is linear up to nyquist-frequency) green: without a reset; blue: with a reset after each 1000 samples
Closeup of plot in picture 2
I would like to be able to explain this behaviour.
I looks like the green graph is the envelope-function of the blue graph, but drops at higher frequencies.
To understand why and how the blue and green graph correlate I tried to understand the fourier-transformation of a ramp-function and a saw-tooth-function. But I cannot wrap my head around it.
The ramp-function is a simple example, it would be great if the explanation is generic for other kind of functions ( sin e.g. ) in the "green" graph.