Re: [Discuss-gnuradio] Question about new modulation schemes dbpsk2

[Tom Rondeau]

On Thu, Nov 11, 2010 at 8:02 PM, John Andrews <address@hidden> wrote:
> Hi,
> The rrc filter parameters in the new modulation scheme in dbpsk2 confuses
> me. Why is the symbol rate in dbpsk2 equal to "
> 1.0/float(self._samples_per_symbol) " whereas, in dbpsk it was 1.0?
>
> Thanks,
> Mir


It's because we are now using a polyphase filterbank clock recovery
scheme. The PFB takes in a filter prototype and distributes it over
the N-arms of the filterbank. Since we're doing filtering here, I
figured we might as well do the RRC filtering at the same time. So, to
get the prototype set up for the filterbank, you have to rethink how
you structure it. This change is part of that.

Tom