On Tue, Apr 13, 2010 at 1:11 AM, Ian Holland <[email protected]> wrote: > > Hi All > > I have been studying up on the Costas loop, and have a couple of queries as > to the benchmark_tx.py and benchmark_rx.py as a result. > > Firstly, for BPSK, there should in theory be a 180 deg. phase ambiguity when > using a Costas loop. Why does this not seem to occur with the > benchmark_rx.py example? Is this related somehow to the PN code introduced > by the scrambler.
Another point of clarification for the way benchmark_rx works. We use differential modulation to account for the phase ambiguity. For BPSK, there would indeed be a 180 degree ambiguity, but we use DBPSK, which is insensitive to that. For anyone wanting to use non-differential BPSK, you would have to use information in the preamble to account for that. Tom _______________________________________________ Discuss-gnuradio mailing list [email protected] http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
