Forum Discussion
Altera_Forum
Honored Contributor
Honored ContributorIFFT Info !
Allo, I would like to have a output of 8192 samples @ 16bits real only with IFFT core. I have a input of 4096 samples@16bits in real only (imaginary is 0) !! It's correct ? I set ...
Altera_ForumHonored Contributor
Honored ContributorI don't know about your IP core but can talk cofdm theory:
Your vector is 4096 points, Your Fs = 100MHz , your target is that first point on this grid(frequency 1 after dc) = 12.207KHz All you have to do is think of an input that has a grid of 8192 in the first place. Then you set this vector to values for amplitude at all frequencies up to 50MHz: (100MHz * 1/8192 = 12.207KHz). (100MHz * 4096/8192 = 50MHz). If you are constructing the vector then yes you first think of 4096 then make amplitudes beyond 4096 a reflection of 1:4096 as below vector_8192 = [1:4096 4096:1] Though strictly speaking I believe, the dc value should not be repeated at reflection.
