RE: [Discuss-gnuradio] How to decode the convolutional code in the GRC

[intermilan]

Ben:
      Thanks for your last e-mail.What I want to see is  the point of my case is to see the BER of data when convolutional code is used in the different modulator.So DBPSK block is just one example,and these cases are particular asked to do in the GRC by my supervisor。I will try what you tell me to do to see if it works.Thanks again.

inter

> Date: Fri, 11 Mar 2011 20:51:44 -0700
> Subject: Re: [Discuss-gnuradio] How to decode the convolutional code in the GRC
> From: address@hidden
> To: address@hidden; address@hidden
>
> You're right my suggestion won't work since the demodulation blocks
> output bits, and the viterbi_combined block expects complex symbols.
> I'll try again.
>
> How about something like the dbpsk block
> (gnuradio-core/src/python/gnuradio/blks2impl/dbpsk.py) but with the
> constellation_decoder replaced with trellis_viterbi_combined. If I
> was going to do this I wouldn't try to do it in GRC, but it is
> probably possible.
>
> Ben
>
> 2011/3/11 intermilan <address@hidden>:
> > Ben:
> >      Thanks for your reply.I knew that block you mentioned.And I know if I
> > use the block chunks_to_symbols after the trellis_encoder,that parameter
> > constellation should be the same as the parameter symbol_table in the
> > chunks_to_symbols.And  I think this is TCM.
> >      But in my flow graph,there is no chunks_to_symbols block,then I do not
> > know how to set that parameter, so I do not know how to decode the data.Do
> > you know how to set that parameter constellation in the block
> > trellis_viterbi_combined if I used this block in my flow graph?
> >
> >   inter
> >
> >
> >> Date: Thu, 10 Mar 2011 22:33:36 -0700
> >> Subject: Re: [Discuss-gnuradio] How to decode the convolutional code in
> >> the GRC
> >> From: address@hidden
> >> To: address@hidden; address@hidden
> >>
> >> You probably want to use the trellis_viterbi_combined block.
> >>
> >> The documentation for the trellis blocks is in
> >> gnuradio/gr-trellis/doc/gr-trellis.xml.
> >> (if you have xmlto installed then an html file is also built.)
> >>
> >> Ben
> >>
> >> 2011/3/10 intermilan <address@hidden>:
> >> > Hi all:
> >> >       Now I want to use the Trellis_encoder block in the GRC to make an
> >> > example for the convolutional code.In my opinion, I use Trellis_encoder
> >> > to
> >> > produce the convolutional code,  then make the convolutional code
> >> > through
> >> > the modulator and demodulator(such as DPSK), finally use some block to
> >> > decode the convolutional code to get the original data.But after the
> >> > data
> >> > get out the demodulator,I do not know how to decode it.
> >> >      Here is the flow graph I used:
> >> >
> >> >
> >> > vector_source->throttle->Packed_to_Unpacked->Trellis_encoder->Packet_encoder->DPSK_mod->DPSK_demod->Packet_decoder->?
> >> >     Can anyone tell me which block I should use after the Packet_decoder
> >> > to
> >> > decode the convolutional code?
> >> >
> >> >
> >> > Thank you in advance.
> >> >
> >> > _______________________________________________
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> >> > address@hidden
> >> > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
> >> >
> >> >
> >
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