Patent ID: 8307255

Claim:
A method of layer message updating, said method comprising: initializing a belief information of each bit (corresponding to a column in H matrix) with a log-likelihood-ratio LLR value; initializing extrinsic information from a check node m (corresponding to a row in H matrix) to a bit n to 0; performing iteration in a block row order, for each row m in a block row M, a plurality of sub-matrixes in said block row are scanned through twice, wherein each non-zero sub-matrix will have W positions with a ‘1’ in the H matrix; before a first scan; initializing two variables for a first minimum and a second minimum to maximum possible positive value; for each non-zero submatrix in a plurality of N sub-matrixes in said block row m, a plurality of W bits (n 1 , nw, . . . nW) are obtained; calculating said extrinsic information from bit n 1 , nw, . . . nW to check m; comparing a plurality of values |Q m,n1 |, |Q m,nw |, . . . |Q m,nW |against said first minimum and said second minimum to find a new first minimum value and a new second minimum value; storing said new minimum values; recording an index of a minimum Q value (P m ) and sign bits for all Q values; after a second scan; said LLR values are updated, for each column n, there are W rows (m 1 .mw, . . . , mW) having ‘1’ in the current block row; updating said extrinsic information; updating said LLR value; and outputting said LLR value when specific stopping criteria are met.