[Discuss-gnuradio] OFDM and FEC combined

[Davi Brilhante]

I am working with the OFDM and FEC blocks combined in the same flowgraph, but this configuration led to some issues and I am not being able to sort 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:

OFDM:

* 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 works perfectly fine. But apparently there is a bug with their integration

Then, I created file sinks in the flowgraph for debugging: One just after 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 after all OFDM process.

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

 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 with "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 "Header/Payload Demuxer".

Best Regards,

Davi