Multi-path Algebraic Codebook Search Algorithm in Low Bit-rate DP-CELP Speech Coding

In order to reduce high complexity for algebraic codebook search in high quality dispersed-pulse CELP speech coding, a multi-path algorithm was proposed in DP-CELP coder at 4 kb/s by keeping relatively maximum correlation between target signal and impulse response in the possible position of pulse. The complexity of the algebraic codebook search is reduced to 0.069 4 MOPS from 19.66 MOPS by using this method. Subjective and objective hearing test indicates that the reconstructed speech quality has no perceptual difference from the original one.