Good morning Jeff! Thanks for the code snippet. I am trying to find the number of data symbols covered by the prototype filter and from your code snippet I can calculate it. It's ncoeff/sps. Thank you! George
On Fri, Aug 6, 2021, 2:10 PM Jeff Long <willco...@gmail.com> wrote: > From generic_mod_demod.py, here is how the taps are generated. The taps > are then used by a polyphase filterbank-based arbitrary resampler. I think > the answer to your question is 11. > > nfilts = 32 > ntaps_per_filt = 11 > ntaps = nfilts * ntaps_per_filt * int(self._samples_per_symbol) > # make nfilts filters of ntaps each > self.rrc_taps = filter.firdes.root_raised_cosine( > nfilts, # gain > nfilts, # sampling rate based on 32 filters in > resampler > 1.0, # symbol rate > self._excess_bw, # excess bandwidth (roll-off factor) > ntaps) > self.rrc_filter = > filter.pfb_arb_resampler_ccf(self._samples_per_symbol, > self.rrc_taps) > > On Fri, Aug 6, 2021 at 2:24 PM George Edwards <gedwards....@gmail.com> > wrote: > >> Hello GNURadio Community, >> >> The constellation modulator has an RRC filter and we are allowed to set >> the alpha and the number of samples per symbol parameters. >> >> An RRC filter is normally designed to cover a number of symbols to the >> right and left from the center of its impulse response. Anyone know the >> number of symbols covered in the GNURadio Constellation Modulator? >> >> Thanks very much! >> >> Regards, >> George >> >
