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

[intermilan]

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.