Re: [Discuss-gnuradio] MPSK Receiver Class

[Tom Rondeau]

On Thu, Sep 13, 2012 at 11:03 AM, Ed Criscuolo
<address@hidden> wrote:
> In my current project, I'm using the MPSK Receiver Class to receive
> a QPSK modulated signal.  We have requirements to log the frequency
> and phase offsets from the spec more-or-less continuously in order to
> do doppler-related post-processing.
>
> Is there any way to get the current frequency & phase values that
> the MPSK Receiver Class's loop(s) are locked to?  I've looked
> through the 3.6.1 Doxygen docs for this class, but didn't find any
> accessor methods for these values.
>
> @(^.^)@  Ed

Hi Ed,

It might depend a bit on what version you are using. Since 3.6, the
mpsk_receiver has inherited from gri_control_loop, which does the work
of keeping track of this information for you. You should be able to
use "get_frequency()" and "get_phase()" for these numbers.

If you need the information continuously, though, you might think
about reworking the receiver code to have 3 outputs instead of one.
You should be able to use 'gr_make_io_signature3(3, 3,
sizeof(gr_complex), float, float)' so you can send the phase and
frequency values directly to a streaming port. That way, you can get
every value of these two fields.

By the way, I'm probably going to change this in 3.7 to have
"frequency()" and "phase()" instead of the "get_" prefix to keep it in
line with all of the other accessors.

Tom