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Altera_Forum's avatar
Altera_Forum
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16 years ago

Little problem with IFFT core v :9.0

I have 8192 bins (4095 .. 0 .. 4095) the last 4095 is a miror from first 4095 bins Sampling Frequency : 100MHz Bandwith : 50MHz Resolution : 50MHz / 4096 : 12.207 KHz For a t...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

Is your altera ifft/fft dc centred. My understanding it is not. So you should arrange your vector indexed from 0 ~ 8191 mirrored in the middle with 0 index being dc.

your vector assumption:

-50....|..............dc..............|....+50

ifft assumption:

dc....|..............+50..............|....dc

so still symmetrical but the difference is in frequency value. You should get:

100*82/8192 = 1MHz