Expurgated Bound Estimation of LDPC Codes

The expurgated bound is proposed to evaluate good LDPC codes in this paper. To get the expurgated bound for LDPC codes needs to know the weights´ distribution of LDPC codes to be evaluated, while the calculation of the weights´ distribution is NP problem. To solve the problem, an expurgated bound of LDPC codes based on generator matrices is developed. Since the weights´ distribution is obtained by the tested generator matrix of given LDPC codes, the expurgated bound of the given codes can reflect the BER performance of the codes. Simulations verify the results to be valid