GNURadio CC encoding/decoding - Using FEC Extended Encoder/Decoder blocks

Hi there! I’m trying to implement CC encoding/decoding in GNU Radio. As can be seen from image below, random data is generated and frames built through periodically ASM word insertion. Among some other necessary blocks, a FEC Extended Encoder block is connected back-to-back with a FEC Extended Decoder block. CC object definition parameters used in each FEC block are the same/equivalent. Two branches delayed 1 bit from each other are used in order to account for the 2 bits ambiguity at decoding stage. Finally, ASM synchronization blocks are used to rebuild frames with fixed length from decoded data. Given sync blocks do not include detected ASM word in generated PDUs, the packet length was set to 1024 bytes (instead of 1020 bytes) to be able to see ASM word corresponding to next frame at the end of PDU content.

Execution results are not as expected. No frame detections. While debugging, it was noticed that if Throttle block is bypassed detections start to occur at a quite regular rate. However, it was not possible to see ASM word at the end of each rebuilt frame. Does anybody have any clue that explains what is going on here?

Thanks so much in advance.

Hi, and welcome.
I’m not sure you’re going to get much response here, might be better to check out #gnuradio channel.

Hi, thanks for the reply! I take the advice and ask there.