Irregular LDPC codes as concatenation of regular LDPC codes
M.P.C. Fossorier, N. Miladinovic · IEEE Communications Letters · 2005
In this letter, the construction of irregular LDPC codes obtained by concatenating regular ones is considered. These codes are analyzed for the binary symmetric channel (BSC). It is shown via proper distribution evolution that such concatenated codes have in general a threshold value weaker (but not necessarily much different) than their unconstrained counterparts for the BSC. On the other hand, they can offer advantages in term of convergence and error performance for lengths of practical interest and long enough to validate the degree distribution selection.