A multi-band CELP wideband speech coder

A novel low-delay wideband speech coder, called multiband CELP (MB-CELP), overcomes the major obstacles usually associated with two traditional CELP approaches to wideband speech coding-namely fullband CELP and split-band CELP. The new MB-CELP coder employs a multi-band bank of off-line filtered excitation codebooks, fullband linear prediction synthesis, and minimization of the error between the original and the synthesized speech signal over the full frequency range. A 16 kbps version of the MB-CELP coder with two equal bands, is described. Subjective comparison test results show that this coder performs better than the G.722 coder at a bit-rate of 48 kbps.