Limiting error propagation in Viterbi decoding of convolutional codes

The problem of avoiding infinite error propagation in noncatastrophic convolutional codes when using a truncated Viterbi decoder is considered. A truncation length τ is defined in terms of walks in the state diagram. The truncation length guarantees that, in the presence of a sufficiently long guard space, a truncated Viterbi decoder will always recover from any error event. This value of τ is the theoretically smallest possible truncation length