Patent Document ID: 20070300139
Application ID: 11635832
Patent Flag: 0

Claim One:
1. A decoding process for decoding a received block of N systematic binary data samples or N systematic duobinary data samples using a maximum a posteriori probability (MAP) decoding algorithm, the decoding process comprising the steps of: a) for each of N/2 pairs of systematic binary data samples in the received block or each of N/2 pairs of duobinary data samples in the received block, calculating a set of four log-likelihood (λ 00 , λ 01 , λ 10 , λ 11 ) values using the corresponding forward state metric (α) values, reverse state metric (β) values, and branch metric (γ) values; b) for each set of four log-likelihood (λ 00 , λ 01 , λ 10 , λ 11 ) values calculated in step a), calculating a delta value corresponding to the difference between the largest and the second largest of the four log-likelihood (λ 00 , λ 01 , λ 10 , λ 11 ) values in each set; c) repeating steps a) and b) for at least a second iteration; and d) stopping the decoding process based on a plurality of delta values calculated during two consecutive iterations of steps a) and b).