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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,

Strange, using the latest Quartus 8.1 I've got correct result by using the original FFT/IFFT unity gain example without introducing any delay.

Since I'm interested in frequency doamin processing I've purposely added unit delay between FFT source real/imag and IFFT sink real/imag. The result is not very encouraging since don't have the correct result anymore. I've verified this with a RAM module in place of the unit delay and it gives the same error result. Is it something to do with the control flag between FFT and IFFT core? If that the case how can I delay them appropriately to handle the extra processing in the frequency domain?

I'm attaching the screen shot of the incorrect result.

Regards,

Wimax