On Wed, Aug 26, 2015 at 8:07 PM, Eric Eric <li...@ruby-forum.com> wrote:

> Hi,
>
> I would like to be able to change the code rate with PSK and QAM
> modulations (e.g QPSK 3/4, 16QAM 1/2). I was thinking of using a FEC
> encoder/decoder as you can see in the attached files but it doesn't
> really work. I'm trying to send a video file and I would like to be able
> to read the received video. What can I do to make it work or is there
> another way to change the coding rate?
>
> Thanks
>
> Attachments:
> http://www.ruby-forum.com/attachment/11055/fec1.jpg
> http://www.ruby-forum.com/attachment/11056/fec2.jpg
> http://www.ruby-forum.com/attachment/11057/fec3.jpg



Dynamics here haven't been tested much. A lot of the codes defined now are
single-purpose because there's a lot of initialization and setup that
occurs that might interfere with the running of things. It'd be interesting
to see where different codes can be modified live. But for the CC
encoder/decoder you're using, look at the man page:

http://gnuradio.org/doc/doxygen/classgr_1_1fec_1_1code_1_1cc__decoder.html

That code is highly optimized to do that one rate and K factor that it does.

You might have better luck making multiple variables and switching them in
and out of the FEC extended encoder/decoder blocks. I feel we might have to
do something to invalidate any data due to changes in cipher/plain text,
though.

Tom
_______________________________________________
Discuss-gnuradio mailing list
Discuss-gnuradio@gnu.org
https://lists.gnu.org/mailman/listinfo/discuss-gnuradio

Reply via email to