| 摘要 |
PROBLEM TO BE SOLVED: To reproduce a high quality voice with a less bit rate. SOLUTION: An input voice is made to pass a linear predictive reverse filter 14 through, and a residual signal r(t) is obtained, and this is cut out by one pitch period at every one frame (25ms) 31, and its cut off r(t) is made so that its peak position becomes a fixed level, and this waveform is vector quantized using one cut off by one pitch periodic length from a code book consisting of code vectors that peaks are arranged. At a decoding time, the waveforms between two waveform vectors in front/behind, and between two pitch periods in front/behind are formed respectively by a linear interpolation method, and interpolated waveform vectors are connected successively by interpolated pitch periods, and a continuous exciting signal is obtained. |
