Protograph LDPC codes design based on EXIT analysis

In this paper, a novel extrinsic information transfer (EXIT) analysis is presented for protograph-based and multiedge type low-density parity-check (LDPC) codes. A protograph defines a subset of an LDPCC ensemble (identified by the degree distributions of the bipartite graph), introducing further constraints about the edge connections. For many codes belonging to this class, the conventional approach based on EXIT charts cannot be applied. The proposed EXIT analysis takes into account edge connections, permitting the decoding convergence evaluation for protograph-based LDPC codes, allowing the design of highly-structured capacity approaching LDPC codes.