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 <tianxia...@hotmail.com>: > 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: b...@reynwar.net >> To: tianxia...@hotmail.com; discuss-gnuradio@gnu.org >> >> 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 <tianxia...@hotmail.com>: >> > 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. >> > >> > _______________________________________________ >> > Discuss-gnuradio mailing list >> > Discuss-gnuradio@gnu.org >> > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio >> > >> > > > _______________________________________________ > Discuss-gnuradio mailing list > Discuss-gnuradio@gnu.org > http://lists.gnu.org/mailman/listinfo/discuss-gnuradio > > _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
