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Altera_Forum
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16 years ago

frequency spectrum

Hallo, I worked with the Altera FFT Megafunction.At the output i have an imaginery and a real part. but the output (sourcereal and sourceim)in the simulator is time-dependent. How can i get the fr...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

The I/Q of fft is the frequency domain.

so just plot the absolute value of output.

IQ = I + jQ;

power = 20* log10(abs(IQ)); %dB

f = linspace(-.5*Fs,.5*Fs,fft_points) % if centered on dc else

%f = linspace(0,1*Fs,fft_points);

%Fs = fft clock frequency

plot(f,power)