Let a = a complex sine with frequency fs/4, ie:
a = [1, j, -1, -j, 1, j, -1, -j];
Let b = a complex sine with frequency negative fs/4, ie:
b = [-j, -1, j, 1, -j, -1, j, 1];
Doing an FFT with MATLAB puts these two peaks at fs/4 and 3*fs/4, as expected, ie:
abs(fft( a )) = [0 0 8 0 0 0 0 0]
abs(fft( b )) = [0 0 0 0 0 0 8 0]
By contrast, CUFFT puts both peaks at more or less the same position. This leads me to believe that MATLAB complex ffts go from 0…2*Pi, whereas CUFFT’s only go from 0…Pi (and mirrors stuff above Pi back down onto the spectrum). Am I correct? If so, shouldn’t CUFFT have the same behavior as MATLAB in this case?
Thanks for any insight.