English

Construction of Near-Capacity Protograph LDPC Code Sequences with Block-Error Thresholds

Information Theory 2016-11-18 v1 math.IT

Abstract

Density evolution for protograph Low-Density Parity-Check (LDPC) codes is considered, and it is shown that the message-error rate falls double-exponentially with iterations whenever the degree-2 subgraph of the protograph is cycle-free and noise level is below threshold. Conditions for stability of protograph density evolution are established and related to the structure of the protograph. Using large-girth graphs, sequences of protograph LDPC codes with block-error threshold equal to bit-error threshold and block-error rate falling near-exponentially with blocklength are constructed deterministically. Small-sized protographs are optimized to obtain thresholds near capacity for binary erasure and binary-input Gaussian channels.

Keywords

Cite

@article{arxiv.1510.06828,
  title  = {Construction of Near-Capacity Protograph LDPC Code Sequences with Block-Error Thresholds},
  author = {Asit Kumar Pradhan and Andrew Thangaraj and Arunkumar Subramanian},
  journal= {arXiv preprint arXiv:1510.06828},
  year   = {2016}
}

Comments

to appear in the IEEE Transactions on Communications

R2 v1 2026-06-22T11:27:12.825Z