Patent Document ID: 20090063939
Application ID: 11860668
Patent Flag: 0

Claim One:
1. A decoder that is operable to perform radix-4 SOVA (Soft Output Viterbi Algorithm) decoding of a signal, the decoder comprising: an ACS (Add Compare Select) module that is operable to: receive a plurality of state metrics and a plurality of branch metrics corresponding to each state of plurality of states of a trellis at a previous trellis stage located two trellis stages from a current trellis stage; process the plurality of state metrics and the plurality of branch metrics to generate a first hard decision for a bit corresponding to the current trellis stage and a second hard decision for a bit corresponding to a previous trellis stage located one trellis stage from the current trellis stage; and process the plurality of state metrics and the plurality of branch metrics to generate a first reliability of the first hard decision and a second reliability of the second hard decision; and wherein: a REX (Register Exchange) module that is operable to process the first hard decision, the first reliability, the second hard decision, and the second reliability to make an estimate of at least one information bit encoded within the signal.