Patent ID: 7054392
Filing Date: 2006-05-30
Classification: H04L

Abstract:
1. A process for estimating successive values of digital symbols based upon successive values of digital samples, with each symbol having M different possible values and each sample resulting from a combination of at most L successive symbols, the process comprising: progressing stage-by-stage through a Viterbi trellis with M partitioning into M groups all transitions arriving at the various states of a current stage of the trellis when taking into account a sample of rank n, with each group containing all the transitions arising from the states of a preceding stage which are associated with one of the M possible values of a symbol of rank n−k; calculating the various aggregate metrics for the various states of the current stage of the trellis, and determining in each group one of the transitions which leads to the state provided with an extremum aggregate metric; and selecting a unique decision regarding the value of the symbol of rank n−k by detecting the group associated with the extremum of M extremum aggregate metrics, the unique decision being provided with a symbol-confidence index formulated from the M extremum aggregate metrics.