Re: antialiasing and decimation

andrea wrote:
is there a way to decimate a signal (reduce sampling rate) reducing
aliasing without implementing a computationally intensive low-pass
filter?
Consider that this signal is supposed to have frequency components
higher than the reduced sampling rate.

If the frequency components higher than half the reduced sampling
are completely characterized, you might be able to subtract or
otherwise account for them after decimation without low-pass
filtering.

e.g. you could implement a computationally intensive high-pass
filter instead, decimate the original and the high band component,
then subtract. This might actually be useful if the there is something
known about the high band component that makes it easier to filter.

Or perhaps the low band signal of interest does not overlap
with the aliased image of the high band component. In that case
you might not even need to subtract the interference after
decimating.


IMHO. YMMV.
--
rhn A.T nicholson d.0.t C-o-M

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