Improvement and simulation for the ACELP speech encoding algorithm

The algebra code-excited linear prediction(ACELP) is the core algorithm of a lot of low bit rate speech coding standards, including the 3G speech standard VSELP, AMR, AMR-NB, AMR-WB. The algorithm is based on code excited linear prediction model. The pitch delay is determined by the effective codebook search. The algorithm´s time complexity is O (n³). Based on the ACELP,this paper propose an improved algorithm called E-ACELP. E-ACELP reduce the time of codebook search and time complexity through the simulation of eight ratios for AMR. The performance and efficiency of the standards all that based on ACELP are improved.