Average Bit Erasure Probability of Regular LDPC Code Ensembles under MAP Decoding over BEC

The average bit erasure probability of a binary linear code ensemble under maximum a-posteriori probability (MAP) decoding over binary erasure channel (BEC) can be calculated with the average support weight distribution of the ensemble via the EXIT function and the shortened information function. In this paper, we formulate the relationship between the average bit erasure probability under MAP decoding over BEC and the average support weight distribution for a binary linear code ensemble. Then, we formulate the average support weight distribution and the average bit erasure probability under MAP decoding over BEC for regular LDPC code ensembles. key words: regular LDPC code ensemble, a-posteriori probability decoding, binary erasure channel, EXIT function, shortened information function, support weight distribution