In this paper we focus on the problem of improving the performance of a speech and channel coder under very bad channel conditions. The study has been tailored to the half-rate sub-system of the pan-European Digital Mobile Radio system. Two major aspects are investigated: the first relates to the reliability of the most important bits in the received bit-stream and the second concerns the use of adaptive post-filtering to cope with errors over those bits related to the excitation parameters.
Bibliographic reference. Sereno, Daniele (1991): "Frame substitution and adaptive post-filtering in speech coding", In EUROSPEECH-1991, 595-598.