Generating reliability values for iterative decoding of block codes

摘要

An iterative decoder arranges calculation of updated reliability values for a current iteration of an iterative decoder so as to reduce the number of comparison operations. The variables for the magnitude and sign of the updated reliability value are initialized. A search of the previous reliability values generates first and second minimum magnitude values for each row (if the iterative decoder is decoding in the horizontal direction) or column (if the iterative decoder is decoding in the vertical direction). A test determines whether the magnitude of the previous reliability value is greater than the first minimum magnitude value m1. If so, the magnitude of the updated reliability value is set as the value m1. Otherwise, the magnitude of the updated reliability value is set as the second minimum magnitude value m2. The sign of the updated reliability value is tracked and assigned once the updated reliability value is set.