OFDM and FEC combined

I am working with the OFDM and FEC blocks combined in the same
but this configuration led to some issues and I am not being able to
this out.

I am using the OFDM Transmitter and Receiver Hier Blocks and FEC Encoder
and Decoder, but I already used “FEC Extended Decoder/Encoder” with
convolutional and dummy variables. With the following parameters:


  • FFT Length: 64
  • CP Lenght: 16
  • Packet Length: 96

FEC (Repetition)

  • Frame Bits: 2048
  • Repetitions: 2
  • a prior prob: 500m

I have made individual tests using this configuration and each block
perfectly fine. But apparently there is a bug with their integration

Then, I created file sinks in the flowgraph for debugging: One just
the encoder, to show me how the repetition encoder works and if it’s
working properly; other after the receiver, to look into the packet
all OFDM process.

The file after reception lost part of the packets, thus, I believe it
that they are being dropped somewhere between transmission and

For example:

If I am transmitting: “A B C\nD E F\nG H I\n”
I am receiving: “A B C\nG H I\nD E F\nG H I\nA B C\n”, i.e. one packet
“D E F\n” and other with “A B C\n” were dropped or lost along the way.

After searching for this type of problem, I found something about

Best Regards,