Patent ID: 6973615

Claim:
A system for determining one or more state probabilities for one or more states in a trellis representation, the system comprising: branch metric logic for determining one or more branch metrics for one or more branches between one or more states in a first portion of the trellis and one or more states in a second portion of the trellis; and state probability logic for determining one or more state probabilities for one or more of the states, comprising: first logic for determining for each of one or more branches a branch value, a branch connecting an originating state with a terminating state, the originating state having a forward state probability and the terminating state having a backward state probability, wherein a branch value for a branch is either the sum of the forward state probability of the originating state of the branch and the branch metric for the branch or the backward state probability of the terminating state of the branch and the branch metric for the branch; and second logic for deriving a state probability for a state from a group operation performed on the branch values for one or more branches.