Patent ID: 7127666

Claim:
An apparatus for executing a Viterbi algorithm, comprising: initial state registers each storing a state metric of an initial state of a trellis having a butterfly structure, a state metric, and a transition metric; at least one transition register storing the transition metric of the trellis; evaluation units; an adder/subtracter network for processing signals, said adder/subtracter network connected: to said initial state registers; to said at least one transition register; and to said evaluation units in accordance with the butterfly structure of the trellis; said evaluation units evaluating signals processed by said adder/subtracter network in accordance with a Viterbi algorithm; a selection unit switching the apparatus between a first operating mode and a second operating mode, wherein the first operating mode is in a different field of operation than the second operating mode; final state registers connected to said evaluation units, each of said final state registers storing the state metric of a respective final state of the trellis; and said selection unit selecting different ones of said evaluation units in dependence upon a selected one of said first and second operating modes.