| 主权项 |
1. A system for simple greedy scheduling of check node equation updates, for at least M equations, where 1<M≦N−K, during an iteration in decoding of codes represented by a parity check matrix with N−K parity check rows and N columns, the system comprising:
a de-mapper; and at least one decoder coupled to the de-mapper and configured to perform the following steps:
a. for each check node i, out of M check nodes of the parity check matrix, calculating Vali=Min1+Min2, i=1, 2, . . . , L where L≧1 and where Min1 and Min2 are the two smallest values in a set of absolute values of variable-to-check messages {|MVC(i,:)|} where index i corresponds to the set of check nodes,b. sorting the set {Vali} calculated in step a in decreasing order to obtain an ordering vector I={I1, I2, . . . , IM}, such that I1 is the index of a check node with the largest value Val, I2 is the index of a check node with the next largest value Val and IM is the index of a check node with the smallest value Val,c. updating M check node equations as MVCnew, according to the ordering vector, I={I1, I2, . . . , IM} calculated in step b, by calculating and propagating corresponding check-to-variable messages, andd. identifying a valid codeword associated with a parity check equation based on the updated variable-to-check messages MVCnew. |
