I tried to modify the setup to use PlutoSDR for transmission and built the GNU Radio flow graph as shown in the figure, but encountered the following error.

[tianchen354]

frame = 0, snr = 10.74, LDPC decoder failed at converging to a code word.
frame = 0, BCH decoder too many bit errors.
frame = 1, BCH decoder too many bit errors.
Baseband header crc failed.
frame = 2, BCH decoder too many bit errors.
frame = 3, BCH decoder too many bit errors.
Baseband header crc failed.
frame = 4, BCH decoder too many bit errors.
frame = 5, BCH decoder too many bit errors.
Baseband header crc failed.
frame = 6, BCH decoder too many bit errors.
frame = 7, BCH decoder too many bit errors.
Baseband header crc failed.
frame = 8, BCH decoder too many bit errors.
frame = 9, BCH decoder too many bit errors.
Baseband header crc failed.
frame = 10, BCH decoder too many bit errors.
frame = 11, BCH decoder too many bit errors.
Baseband header crc failed.
frame = 12, BCH decoder too many bit errors.
frame = 13, BCH decoder too many bit errors.
Baseband header crc failed.

frame = 14, BCH decoder too many bit errors.

[tianchen354]

could anyone please give some help，

[drmpeg]

It's not possible to use this project to transmit and receive over the air. There are many missing pieces. This project is intended to be just a showcase for an LDPC decoder.

If you want to transmit and receive over the air, then you want to use the other gr-dvbs2rx that implements an entire receiver.

https://github.com/igorauad/gr-dvbs2rx

[tianchen354]

Oh, I see. This project doesn't cover all the processes, does it? Thank you for your reply. As for the link https://github.com/igorauad/gr-dvbs2rx, I had seen it before. Because I am currently using GNU Radio 3.8, I encountered some issues when building the project earlier. It seems that this project requires GNU Radio 3.9, is that right? I am currently installing version 3.9 to try again. Thank you again for your reply.By the way, one last question: have you tried building this project (https://github.com/igorauad/gr-dvbs2rx) using GNU Radio 3.8? 田晨 ***@***.***

[drmpeg]

Looks like https://github.com/igorauad/gr-dvbs2rx requires 3.10.

https://github.com/igorauad/gr-dvbs2rx/blob/master/CMakeLists.txt#L77