--- Quote Start ---
I mean the exponent is 6bits signed and can range from 1 to -15, referring to page A-2 of the FFT user guide.
The user guide tells to scale the output with the exponent value of the processed block. Doesn't that mean that I have scale every block of 1024 points I process? But if not, what is the exponent output for?
The question is: Do I have to use the exponent value? And how do I have to apply it exactly. The goal is to get the amplitude spectrum.
Right now I calculate the magnitude this way:
mag = sqrt(16bitreal^2 + 16bitimag^2) ...(the result is too small)
I also tried:
mag = sqrt((16bitreal^2 * 2^(-exponent)) + (16bitimag^2 * 2^(-exponent)) ) ... the result is too large, compared to the input range.
Is this correct?
--- Quote End ---
yes you apply exponent per block as it varies.
Your scaling formula is correct but how do you implement in hardware. do you apply shift or use multipliers in hardware? or do you get results wrong on paper anyway?
Honored Contributor
