Average Coset Weight Distribution of Multi-Edge type LDPC Code Ensembles

摘要

Multi-Edge type Low-Density Parity-Check codes (MET-LDPC codes) introduced by Richardson and Urbanke are generalized LDPC codes which can be seen as LDPC codes obtained by concatenating some standard (ir)regular LDPC codes. We prove in this paper that MET-LDPC code ensembles possess a certain symmetry with respect to their Average Coset Weight Distributions (ACWD). Using the symmetry, we drive ACWD of MET-LDPC code ensembles from ACWD of their constituent ensembles.