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Re: FFT pad or no pad

Started by umas...@gmail.com January 25, 2011
I have 300sec data collected at 1Hz. I want to look at power spectrum of this time series, so first I need to do FFT(). But I am not sure if I need to pad it with zeros to make it 512. Matlab FFT() lets me do it either way, but I don't really understand which way I should do. Please advise. Thanks.
>
> using FFT() without padding zeros will not create any problems. the reason why we can go for a 512 point (or higher radix 2 point) FFT is that when the fft bloxk is implemented in hardware, the resources needed to implement radix 2 dit or dif structures (or similar ones) is very less.
If you are concerned only about the simulation then there is no big difference. it will just affect your resolution. higher point FFT=> better resolution. :)