On Oct 12, 5:03=A0am, Rick Lyons <R.Lyons@[EMAIL PROTECTED]
> wrote:
> On Tue, 7 Oct 2008 07:13:45 -0700 (PDT), move <liubeny...@[EMAIL PROTECTED]
>
> wrote:
>
>
>
> >Hi all:
>
> >I want to implemnt the filter spec below using CIC + CICCOMP filter
>
> >FS=3D5MHz, fp=3D9k, fst=3D10k, ap=3D0.1, ast=3D100, decimator=3D100
>
> >I am using a Differential delay=3D50 and Number of sections=3D5 CIC
filt=
er
> >and cascading a ciccomp filter which provide an extra 2 decimator. but
> >the cic compensate filter
>
> >fs=3D100k, fp=3D9k, fst=3D10k,ap=3D0.1,ast=3D100 D=3D2
>
> >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.
>
> >any suggestions?
>
> >savor
>
> Hi,
> =A0 If you can get your hands on a copy, perhaps
> the paper:
>
> Kwentus, A., et al, "Application of Filter Sharpening to Cascaded
> Integrator-comb Decimation Filters. IEEE Transactions on Signal
> Processing, Vol. 45, Feb. 1997, pp. 457-467.
>
> will help you flatten the passband of your CIC filter
> so that you don't need so many taps in your
> compensation filter.
>
> You can learn about "filter sharpening" at:
>
> http://www.dsprelated.com/showabstract/62.php
>
> which is Chapter 1 of the
> book "Streamlining Digital Signal Processing, a Tricks
> of the Trade Guidebook" (published by Wiley & Sons and
> the IEEE).
>
> Just a thought.
> Good Luck,
> [-Rick-]
The filter sharpening seem like to be processing the data using the
same filter for many times, I will give it a try!
Thanks, Rick!
about these liquid joke.... -_-!
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