Error Correction Capability of Column-Weight-Three LDPC Codes
Bane Vasic, et al. · 2007
In this paper, we investigate the error correction capability of column-weight-three LDPC codes when decoded using the Gallager A algorithm. We prove that the necessary condition for a code to correct k ≥ 5 errors is to avoid cycles of length up to 2k in its Tanner graph. As a consequence of this result, we show that given any α> 0, ∃N such that ∀n> N, no code in the ensemble of column-weight-three codes can correct all αn or fewer errors. We extend these results to the bit flipping algorithm.