I'm confused as to what to expect when I take, for example, the fourier transform of a sequence of 16 pulses of varying duty cycles, repeating. That is, after the 16th pulse, the entire sequence repeats. My confusion is in the interaction of the frequency components of each pulse within the sequence, and the fact that these repeat at some periodic rate (the sequence repeats). I understand that a single pulse results in a sync function response in the frequency domain. And in a periodic pulse train, the period determines the separation between frequency bins, and the pulse width in the the width of the lobes in the Fourier series. What I don't get then is what happens when we have periodicity at the "group" level (every sequence), but not from one pulse to the next within a sequence (although the pulse width varies, but the period does not ---maybe that's the key). thanks!