CELP coding with an adaptive density pulse excitation model
M. Akamine, K. Miseki · International Conference on Acoustics, Speech, and Signal Processing · 2002
An approach to dynamic bit-allocation to excitation vectors to improve the performance of a code excited linear prediction (CELP) coder is proposed. The method is based on an adaptive density pulse (ADP) excitation. By using the ADP, bit-allocation to the excitation vector can be easily varied. Also, the number of samples of excitation can be reduced. The effects of the ADP parameters on the synthetic speech quality are discussed. The ADP-CELP coder is described. The benefit of introducing the ADP excitation model to the CELP coder is evaluated. The segmental signal-to-noise ratio gains of the ADP-CELP coder over the conventional CELP are about 2 dB both at 8 kbit/s and at 4.8 kbit/s.>