Iterative MAP decoding of block codes using sub-trellises

摘要

A method for decoding block codes includes a step of calculating an a posteriori probability for each incoming input bit involving states related to a Trellis diagram, said method further includes a step of decomposing the parity check matrix into a set of p submatrices, each submatrix being associated with one of p subtrellis diagrams of said Trellis diagram, said method further includes the steps of, per subtrellis, and in parallel calculating auxiliary parameters related to the said a posteriori probability, and a step of combining said auxiliary parameters such as to provide the a posteriori probability parameter. For improving accuracy the method can be further iterated whereby in some embodiments the division of the parity check matrix into a set of submatrices is different from iteration to iteration step.