Patent ID: 6857097

Claim:
A method for evaluating an error-correcting code for a data block of a finite size, comprising; defining an error-correcting code by a parity check matrix; representing the parity check matrix as a bipartite graph; iteratively renormalizing a single node in the bipartite graph until a predetermined threshold is reached; and wherein the bipartite graph includes variable nodes representing variable bits of the data block, and check nodes representing parity bits of the data block, and the renormalizing further comprises: selecting a particular variable node as a target node; selecting a particular node to be renormalized; measuring a distance between the target node and every other node in the bipartite graph; if there is at least one leaf variable node, renormalizing a particular leaf variable node farthest from the target node, otherwise if there is at least one leaf check node, renormalizing a particular leaf check node farthest from the target node, otherwise renormalizing a non-leaf variable node farthest from the target node and having fewest directly connected check nodes.