摘要 |
In an excitation signal encoding method comprising the steps of, dividing a speech signal into a plurality of frames, dividing each of the plurality of frames into a plurality of subframes each of which has a subframe length, and generating a new excitation signal by the use of an adaptive code book comprising a plurality of adaptive code vectors and a sound source code book comprising a plurality of sound source code vectors, the generating step is carried out in a predetermined period when the predetermined period is shorter than the subframe length. The generating step is carried out by the use of the adaptive code vector that is calculated using the excitation signal generated in the former period and by the use of the sound source code vector of the present period. <IMAGE> |