Using parallel-interconnected Viterbi decoders to correct insertion/deletion errors

Abstract

We present a new insertion/deletion correction scheme for standard convolutional codes that makes use of multiple interconnected parallel Viterbi decoders. Whenever an insertion or deletion error occurs, the connections between different Viterbi decoders ensure that decoding proceeds from the decoder that is in synchronization. In this way, a larger Viterbi decoder is created that can correct insertion and/or deletion errors by extending the Viterbi algorithm to encompass all parallel decoders. Further, we show how the performance can be improved by inverting certain bits during the encoding of the convolutional codes, thus lowering the frequency of occurrence for repeating sequences, which is detrimental to synchronization