On Oct 7, 10:13 am, move <liubeny...@[EMAIL PROTECTED]
> wrote:
> I am using a Differential delay=50 and Number of sections=5 CIC filter
> and cascading a ciccomp filter which provide an extra 2 decimator.
I don't think you mean your decimation ratio is 50, not your
differential delay.
One solution is to come out of your CIC at a higher rate, and
decimator by 4 or 8 in your compensation filter. This means that you
are using a narrower slice at the center of the CIC, so there's less
droop to compensate. In fact your may be able to skip compensation
all together. Then what was your compensation filter just becomes a
decimate by four or eight polyphase FIR lowpass.
> will take 404 taps to implement using equiripple method, the taps is
> too long for input data block which is only 200 samples a frame, so
> before next frame is coming, the filter is still full of unprocessed
> last frame data, this will cause the output of nextframe filter in-
> accurate.
Shouldn't you be joining the frames together, processing them as a
continuous stream, and then reframing them again at the output? If
the next frame hasn't arrived, just freeze your filter logic in place
and don't give it another clock until you have data from the next
frame to start feeding in.
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