On the upper bound on undetected error probability for LDPC code

This paper deals with the method of undetected error probability estimation for a low-density parity-check (LDPC) code under any given iterative decoding algorithm. We propose such modification of a given iterative decoding algorithm, that almost preserves a decoding failure exponent and decoding complexity of this algorithm. We obtain the upper bound on the undetected error probability for the modified algorithm. We show how to use the proposed method to estimate the undetected error probability of LDPC code under the belief propagation (BP) algorithm at the end of this paper.