Patent ID: 8196005

Claim:
A method for decoding a Low-Density Parity-Check (LDPC) encoded codeword, the LDPC code being represented by a bipartite graph between check nodes and variable nodes including first variable nodes and second variable nodes of degree two connected to the check nodes via a zigzag connectivity, the method comprising: defining from the check nodes at least two groups of at least two check nodes mutually connected through at least one internal second variable node, each group being connected to a neighboring group by one second variable node defining a connecting second variable node; updating, for each group, by jointly updating the check nodes of the group with a Maximum-A-Posteriori (MAP) type process in a decoder, and updating all the first variable nodes connected to the check nodes of the group and updating each connecting second variable node connected to the group without updating the internal second variable nodes; and iteratively repeating the updating.