Patent ID: 8719686

Claim:
An apparatus for probability-based multi-level low density parity check decoding comprising: a horizontal updater in a low density parity check decoder operable to iteratively perform row processing to update probabilities of multi-level symbol values, wherein the horizontal updater is operable to calculate probabilities of values for a first sum of products of transmitted values and their corresponding non-zero elements from an H matrix for previous columns, and to calculate probabilities of values for a second sum of products of transmitted values and their corresponding non-zero elements from the H matrix for following columns, and to calculate a checksum based on the probabilities of values for the first sum and the second sum; a vertical updater in the low density parity check decoder operable to iteratively perform column processing to update the probabilities of the multi-level symbol values; and a check sum calculation circuit operable to calculate total soft values for the multi-level symbol values.