Decoders with Initial State Invariance for Multivalued Encodings

Multivaluedencodings constitute an interesting generalization of ordinary encodings in that they allow each source symbol to be encoded by more than one codeword. In this paper we characterize the class of multivaluedencodings that admit invariant decoders and provide an algorithm for constructing such decoders. Invariant decoders have the useful property that their behavior does not depend on the state in which they are, thus exhibiting optimal tolerance to accidental state transitions and/or errors in the input sequence.