On Tue, 2017-10-24 at 08:16 -0400, Andy Walls wrote: > Hi Marcus: > > Nice insights and plots. > > > From: Marcus Müller > > Date: Mon, 23 Oct 2017 20:10:23 +0200 > > [snip] > > From the above figure, I'd say: go for 256 taps; 50 dB of anti- > > aliasing should probably suffice. > > On my machine, the 256 tap FIR filter with decimation=64 ran about > > 20% faster than the fractional resampler; comparing what they do to > > white noise, I'd say that whilst the spectral shape of the 256 tap > > FIR is not perfect, the MMSE is pretty much unusable, I guess: > > I'd just like to interject here that GNURadio's MMSE filterbank is > only > MMSE for input spectral components in the range [-sample_rate/4, > sample_rate/4]. > > Also it appears that the mmse/fractional_resampler blocks don't > perform > any explicit anti-alias filtering. So that's another reason to have > a > band-limiting filter out in front of it.
Oopsie, and maybe one after it too, since we're talking about decimation. -Andy _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio