Re: [Discuss-gnuradio] Strange behavior in digital benchmark examples

[Josh Blum]

On 11/04/2011 01:55 PM, Jordan Otomo wrote:
> I think the problematic block might be the FLL used in the PSK
> demodulator.  I haven't looked into the issue very deeply, but I have
> confirmed that given the same input parameters, the FLL from 3.4.2
> works fine, while the 3.5.0 version causes a lot of overruns.
> 

Thanks, I confirmed that the fll band edge filter is the culprit. The
following diff (removing the bandedge) makes may loopback example far
more responsive:

diff --git a/gr-digital/python/generic_mod_demod.py
b/gr-digital/python/generic_mod_demod.py
index ae876e1..cf2d684 100644
--- a/gr-digital/python/generic_mod_demod.py
+++ b/gr-digital/python/generic_mod_demod.py
@@ -303,7 +303,7 @@ class generic_demod(gr.hier_block2):
             self._setup_logging()

         # Connect and Initialize base class
-        blocks = [self, self.agc, self.freq_recov,
+        blocks = [self, self.agc,
                   self.time_recov, self.receiver]
         if differential:
             blocks.append(self.diffdec)

-Josh