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Altera_Forum
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17 years ago

Altera FFT - output scaling. How to do this correctly?

Hi, I do not get correct scaled results if I do everything the FFT user guide recommends. I have instantiated a 1024 points FFT, with single output and burst architecture. The data width...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
17 years ago

You siad your inputis 30146, I assume you checked that in signaltap.

This matlab code can be used as reference:

% generate a sinusoid at 9Hz, Fs at 3Khz

x = round(30146*cos(2*pi*[0:1023]*9/3000));

% fft scaled for unity gain

y = 1/512*fft(x);

plot(abs(y));

max(abs(y))