On Sun, Sep 4, 2011 at 11:33 AM, Ryan Pape <ryan.p...@gmail.com> wrote:
> > We are successfully using the PFB filterbank to channelize 1-6mhz into a > variety of channel widths (25K, 50K etc). > > In one application, we have 25K channels which are then resampled using PFB > resampler to 19.2K fed into gmsk_demod @ 9600bps with 2sps. > > In this case, we may have 20-40 ports "active" (not null sink) with pfb > resamplers connected to each. > > Is there way to perform this resampling in the filterbank to avoid the > need for many separate resampler blocks in an effort to improve performance? > > We are pushing the limits of hardware already, so any efficiencies are > helpful. We will consider a hierarchical filterbank structure if necessary, > but our first goal is to do it with one filterbank, if possible. > Ryan, What you are talking about is possible, but not with the current implementation of the GNU Radio channelizer. fred harris has recently published a few papers on doing arbitrary channel / arbitrary bandwidth channelizers that should meet your needs, but it would have to be programmed up. Now, that having been said, there is a way to handle this. If you have a 9600 bps signal in a 25 ksps channel, you can switch to using the gr_pfb_clock_resampler_fff block, which allows you to specify a real number for the number of samples per symbol (2.6042 in this case) instead of integers. That should do the trick. Tom
_______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
