The Low-Density Parity-Check codes are among the most powerful forward error correcting

codes, since they enable to get as close as a fraction of a dB the Shannon limit.

This astonishing performance combined with their relatively simple decoding algorithm

make these codes very attractive for the next digital transmission system generations. It

is already the case for the next digital satellite broadcasting standard (DVB-S2), where

an irregular LDPC code has been chosen to protect the downlink information.-The Low-Density Parity-Check codes are among the most powerful forward error correcting

codes, since they enable to get as close as a fraction of a dB　the Shannon limit.

This astonishing performance combined with their relatively simple decoding algorithm

make these codes very attractive for the next digital transmission system generations. It

is already the case for the next digital satellite broadcasting standard (DVB-S2), where

an irregular LDPC code has been chosen to protect the downlink information.