Error protection in a low complexity speech codec

This paper proposes a new channel error protection scheme for a low complexity speech codec that is suitable for the Personal Handy-phone System (PHS) multimedia communication. Deterioration of speech quality is suppressed by using CRC and parameter estimation for error protection. Two types of codec are described: a 10-ms frame type that transmits 160 bits every 10 ms and a 15-ms frame type that transmits 160 bits every 15 ms. The computational complexity of these codecs is less than 5 MOPS. In a no-channel error environment, the speech quality is equal to that of G.726 at 32.0 kbit/s. With 0.3% channel error, both codecs offer more comfortable conversation than G.726. Moreover, at 1.0% channel error, the 10-ms frame type still provides comfortable conversation.