| 摘要 |
PROBLEM TO BE SOLVED: To code voice signals employing a small amount of computations while suppressing deterioration in tone quality even though coding bit rate is low and to decode the coded voice signals with high quality. SOLUTION: A plurality of sets of position code book to represent the positions of pulses are stored in a plurality of set position code book storage circuit 450. One kind of the position code book is selected from the plurality of position code books in a position code book selecting circuit 510 based on pitch predicting signals obtained in an adaptive code book circuit 500. A position is selected by a sound source quantization circuit 350 from the selected position code book to minimize distortion with respect to the voice signals. Then, the outputs of the circuits 500 and 350 are transmitted. |
