CODEBOOK SEARCH METHOD USING RPE TECHNIQUE IN THE CELP VOCODER

摘要

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a codebook retrieval method of a voice coder, the method comprising: forming a residual signal from an input voice signal, decimating the residual signal to a predetermined pulse excitation interval at a predetermined ratio, and forming a plurality of excitation sequences; Selecting a dominant energy sequence among the sequences, synthesizing the selected excitation sequence to generate a reference signal, synthesizing by skipping the code vector at a predetermined ratio in an irregular codebook and synthesizing the synthesized signal and the reference signal The irregular codebook is searched by comparing the cognitive weighted input speech signal with the deviation.;Therefore, since the codebook search time is reduced by about 48% compared to the conventional method by increasing the search of the codevector by 3, real-time implementation of the CELP vocoder is possible even with a low-cost DSP chip having a low processing speed.