I was reading up on (discrete) fourier transform when my mind started to think of an what-if scenario:(adsbygoogle = window.adsbygoogle || []).push({});

Assumed I'm sampling a signal of the form

a1*sin(b1+c1) + a2*sin(b2+c2) + a3*sin(b3+c3) + .... + aN*sin(bN+cN) + some noise

where the a's represents magnitudes, b's represents frequencies and c's represents phases.

Assumed it is not know how low the lowest frequency is. It may not even be a full period within the time frame of sampling. Is there any way to find the frequencies represented in the data set?

(As I understand the DFT requires the sample set to be one repeating period of the signal.)

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# A Frequency analysis of signal with unknown period

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