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Altera_Forum's avatar
Altera_Forum
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18 years ago

FFT/IFFT Unity Gain Example

Here is an example that I did a while back when I was playing with the FFT/IFFT core. It was built with DSP Builder 6.1. Also it incorporates the unity gain formula highlighted in the Block floating ...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
17 years ago

Hi, Wimax,

I don't believe there are any huge changes between version 6.1 and 7.0 (I believe the only difference is the Cyclone III support). It seems like you changed the design a bit (your input sine wave merely has amplitude of 5. Mine uses the full 16 bit resolution. The core only takes full precision value (it does not know how to handle decimal points). Therefore, if you are not putting in the full precision, then you might get some error.

Also are you using the same 1024 streaming FFT? If not, you might need to change the input module embedded matlab block. That way the proper sop and eop signals would be generated.

Hope this helps.

- WZ