I have an ECQ signal of 360 Hz sampling frequency. I used an FFT to extract the frequency spectrum of my signal. Now I don't know exactly how to interpret this plot. How can I know the noise from the signal? Why is there a spike at 0 Hz and between 50-75 Hz? Can someone briefly explain to me how to interpret it?
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1 Answer
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The DC (0 Hz) spike is probably due to a constant bias in your data set. This can be mitigated by subtracting the mean of the data set from each sample prior to performing the FFT.
The spike between 50 and 75 Hz looks like it is at 60 Hz. This likely is a result of 60 Hz power supply ripple either leaking into the test equipment or coupling in some other way.
Separating signal from noise? That would probably require more domain specific knowledge or would require additional information to be added to the question.
answered Mar 27, 2022 at 21:50