A robust decoding for long convolutional codes

Sequential decoding is an attractive technique to achieve the reliability of communication promised by the channel coding theory. But, because it utilizes the Fano metric, its performance is sensitive to channel parameter variations and it cannot simultaneously minimize both decoding effort and probability of decoding error. Based on the distance properties of the codes, we have derived a new set of metric which not only can overcome the two drawbacks caused by the Fano metric but also can significantly reduce the decoding effort required by sequential decoding.