Improved Low-Density Parity-Check Codes for Burst Erasure Channels

In this work we deal with Low-Density Parity-Check (LDPC) codes under iterative message passing decoding algorithm, over channels introducing bursts of erasures. The burst erasure channel model we consider in this paper can be seen as an erasure channel based on a hidden Markov chain (HMC-EC). In order to characterize the channel, in the first part of the paper the expression of mutual information is recalled for any erasure channel with memory and with i.i.d. and equiprobable input symbols. In the second part of the paper an optimization algorithm is proposed which is able to heavily improve LDPC iterative decoder performance. This algorithm can be in principle applied to any given LDPC code. Simulation results relative to both random and IRA / eIRA codes are shown comparing the performance before and after the application of our optimization algorithm.