[Discuss-gnuradio] Trying to build a DVB-S2 LDPC decoder

[Jose Ruvalcaba]

Hello,

I am new to GNU radio and to SDR's and I am trying to implement a DVB-S2 LDPC decoder block that can be used with the LDPC DVB-S2 encoder available in GNU radio. I have been able to write an LDPC decoder which uses a 16,200 long parity check matrix used only for a DVB-S2  short frame, rate = 1/4 code. The problem is that when running my written block it's taking a long time to decode one iteration of data(about an hour long). I was wondering if anyone has any advice in how to go about writing code for FEC blocks, especially LDPC codes, which will be used in GNU radio and eventually in an SDR? In other words, are there certain libraries that should be used when trying to write FEC decoders in gnu radio? How could I make a GNU radio FEC block which takes in a codeword length 16,200, like the one in DVB-s2, to work in a USRP? Is it smart to make my large (12960 x 16,200) parity check matrix using the standard 'vector' library in C++?   Any advice, tips and suggestions will be greatly appreciated.

Thanks,
Jose