I have a strongly aperiodic signal and I get weird artifacts after running a fft, using a low-pass filter, and then doing an inverse fft. I believe the artifacts are due to the way the signal is assumed to be periodic and "wrapped" at the ends. (Like I said, I'm a complete beginner here.)
I understand the usual way of handling aperiodic signals is via a window function, but applying a window function (say, Hamming) to my data looks like it squishes the data too much and like it would generate worse artifacts.
What sort of seems like it works is to
surround the signal with silence, by prepending and appending a segment of 0s,
doing the fft, applying the filter, etc., and then inverting the fft, then
clipping off the silence segments off the beginning and end.
The result of step 1 looks like applying a rectangular window function to a longer signal, so I think that's ok, but...
Is what I'm doing in any way reasonable?
If so, what are the effects? And what is the best way to determine the length of the segments of 0s? (Currently, 10% of the original signal seems like it's not bad.)
If not, is there another way to do this?