Re: [Discuss-gnuradio] Bug in DBPSK blocks

[Tom Rondeau]

On Tue, Dec 3, 2013 at 1:52 PM, Nick Foster <address@hidden> wrote:
> Hi all,
>
> There's a bug in the block for the DBPSK modulator. The "differential" param
> isn't set to True in dbpsk_mod; it's just left to default, and differential
> defaults to False in the bpsk_mod block. So it really acts like a BPSK
> modulator. QPSK was the same. Here's a patch.

Thanks for the report and patch, Nick. I should get to it today, but
in the meantime, I opened ticket #624 in case it slips my timeline
today. In the future, best to put these things up on the Issues
tracker.

> diff --git a/gr-digital/python/digital/bpsk.py
> b/gr-digital/python/digital/bpsk.py
> index 57cf253..92f3254 100644
> --- a/gr-digital/python/digital/bpsk.py
> +++ b/gr-digital/python/digital/bpsk.py
> @@ -117,7 +117,7 @@ class dbpsk_mod(bpsk_mod):
>
>      def __init__(self, mod_code=None, *args, **kwargs):
>
> -        super(dbpsk_mod, self).__init__(*args, **kwargs)
> +        super(dbpsk_mod, self).__init__(differential=True, *args, **kwargs)
>
>  #
> /////////////////////////////////////////////////////////////////////////////
>  #                           DBPSK demodulator
> @@ -139,7 +139,7 @@ class dbpsk_demod(bpsk_demod):
>
>      def __init__(self, mod_code=None, *args, **kwargs):
>
> -        super(dbpsk_demod, self).__init__(*args, **kwargs)
> +        super(dbpsk_demod, self).__init__(differential=True, *args,
> **kwargs)
>
>  #
>  # Add these to the mod/demod registry
> diff --git a/gr-digital/python/digital/qpsk.py
> b/gr-digital/python/digital/qpsk.py
> index 859d981..1ed3357 100644
> --- a/gr-digital/python/digital/qpsk.py
> +++ b/gr-digital/python/digital/qpsk.py
> @@ -149,7 +149,7 @@ class dqpsk_mod(qpsk_mod):
>      __doc__ += shared_mod_args
>
>      def __init__(self, mod_code=_def_mod_code, *args, **kwargs):
> -        super(dqpsk_mod, self).__init__(mod_code,
> +        super(dqpsk_mod, self).__init__(mod_code, True,
>                                          *args, **kwargs)
>
>  #
> /////////////////////////////////////////////////////////////////////////////
> @@ -171,7 +171,7 @@ class dqpsk_demod(qpsk_demod):
>      __doc__ += shared_demod_args
>
>      def __init__(self, mod_code=_def_mod_code, *args, **kwargs):
> -        super(dqpsk_demod, self).__init__(mod_code,
> +        super(dqpsk_demod, self).__init__(mod_code, True,
>                                            *args, **kwargs)
>
>  #
>
> Incidentally, I question the need for the DBPSK mod GRC block now that we
> have the generic PSK mod GRC block. Might make sense to deprecate it.
>
> --n

I quite agree. I have a note to myself to clean this up with 3.8.

Tom