On the relation between Viterbi decoding with labels and the SOVA
Both Viterbi decoding with labels (i.e., the Yamamoto-Itoh scheme) and the soft-output Viterbi algorithm (SOVA) evaluate the metric difference between the maximum-likelihood (ML) path and the discarded path at each level in the trellis. Noting this fact, we shaw that the former scheme also provides information about the reliability values for decoded information bits.
viterbi decoding with labels sova symbol reliability list viterbi decoding algorithm