BACKWARD-TYPE EFFICIENT CODING FOR WIDE-BAND SPEECH AND MUSIC SIGNALS (ADPCM-AB).

This paper proposes a new backward speech coding system (ADPCM-AB) for wide-band (7 kHz) speech and music signals. This system employs a split-band adaptive predictive coding scheme with PARCOR lattice filter and dynamic bit allocation, in which the quantization bits are dynamically allocated over sub-bands and stereo channels in accordance with the distribution of residual energies. The ADPCM-AB needs either longer delay time than 5ms nor transmission of side information parameters since linear prediction coefficients and dynamic bit allocation parameters are calculated using locally decoded signals.