A variant of the best-path (BP) algorithm that can be used for deducin
g a posteriori symbol probabilities for input sequences of unlimited l
ength is proposed. Decoders using the proposed algorithm have fixed me
mory requirements and fixed decoding delays regardless of the length o
f the transmitted sequence. This is made possible by utilizing the Vit
erbi algorithm's ability to self-initialize itself and by segmenting t
he decoding process.