A METHOD FOR CALCULATING EXTRINSIC INFORMATION DURING DECODING, A DECODER AND A TURBO DECODER

摘要

A method for calculating extrinsic information during decoding involves receiving a data sequence; back calculating back state metric and branch metric in turn from the bottom of the data sequence, and before finishing the calculation of the back state metric and the branch metric, forward calculating forward state metric and branch metric in turn from the top of the data sequence; calculating and outputting the extrinsic information of the data sequence bit from the calculated back state metric,, forward state metric and the branch metric. Accordingly a decoder and a turbo decoder are disclosed.