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Altera_Forum's avatar
Altera_Forum
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16 years ago

White Noise Spectrum

I have use a simple LFSR to generare random number to generate white noise. Set of random number are pass through to FFT(power in db vs freq). However, the freq response is increasing at low freq. Th...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

Can you please clarify the power scaling of the FFT output? How you calculate a negative power? It appeared to me as a decreasing towards low frequencies.

Now it also looks to me also as a simple DC offset problem, produced by feeding unsigned (positive only) random numbers to the FFT. Of course, the input should be DC balanced. You can calculate the FFT of a constant input to understand the problem.