Patent ID: 7096412

Claim:
A method for generating higher confidence information on data inputs of a process modeled as a finite state machine (FSM) represented by a reduced-state trellis, the FSM receiving a plurality of FSM inputs and producing a plurality of FSM outputs, the FSM inputs being defined on a base set of symbols, the method comprising: (a) inputting said soft decision information in a first index set; (b) performing forward recursion calculations on said reduced-state trellis representation using said input soft decision information and using a forward truncated survivor path comprising decisions not specified by the reduced-state trellis, to produce forward state metrics; (c) performing backward recursion calculations on said reduced-state trellis representation using said input soft decision information and using a backward truncated survivor path comprising decisions not specified by the reduced-state trellis, the backward truncated survivor path being distinct from the forward truncated survivor path, to produce backward state metrics; (d) operating on said forward state metrics and said backward state metrics to produce said higher confidence information; and (e) outputting said higher confidence information.