ITERATIVE DECODING METHOD AS TO BLOCK TURBO CODES ABOVE THREE DIMENSION

摘要

PURPOSE: An iterative decoding method as to block turbo codes above three dimension is provided, which uses soft output information calculated in all other axes as external reliability information at the same time while performing decoding at each axis, and performs iterative decoding by normalizing the soft output properly. CONSTITUTION: According to the method using soft output viterbi algorithm as to block turbo codes which are product codes connecting block codes above three dimension, a transmitter constructs product codes above three dimension and then transmits them. The signal transmitted from the transmitter is constructed as a frame for decoding(S10), and external reliability information corresponding to each axis corresponding to the product codes above three dimension is initialized(S20). Soft output viterbi algorithm(SOVA) is iterated as to each axis in sequence. External reliability information to be used at a specific axis is calculated on the basis of external reliability information calculated in other axis. Soft output information is output by performing decoding using the external reliability information of the specific axis(S30). External reliability information corresponding to the specific axis is calculated which is to be used in a next stage(S40). And it is judged whether an iterative decoding stop condition is satisfied(S50). If the iterative decoding stop condition is satisfied, the iterative decoding is stopped and decoding result is output(S60). If the iterative decoding stop condition is not satisfied, external reliability information of each axis is normalized(S70).