Viterbi decoding using single-wrong-turn correction

Abstract

A recursive, single-wrong-turn (SWT) decoding method and Viterbi decoder which requires no additional circuitry or processing to keep track of a running list of the L best paths. If the most likely (ML) path fails frame quality metric tests, a search is made through a trellis using an existing survivor (trace back) information stored in a survivor (trace back) memory. An iteration in the recursive algorithm includes tracing back along the ML path to a particular stage, then deviating from the ML path and following the survivor information along that new deviant path, and finally checking the fully decoded frame to see if the frame quality metrics are acceptable for the frame. These same trace back steps can be performed for every stage in the trellis, deviating from a different stage on the ML path each time. A recursive, single-wrong-turn (SWT) decoding method and Viterbi decoder which exceed the performance of the general Viterbi algorithm and the various conventional list Viterbi decoders and which is much less computationally and physical complex.