| 摘要 |
PROBLEM TO BE SOLVED: To provide a signal encoding device for obtaining fine tone quality for a voice or a musical signal even at a low bit rate. SOLUTION: An input signal is predicted in a prediction circuit 300 and the predicted residual signal is subjected to orthogonal transformation in a first orthogonal transform circuit 320. In a coefficient calculating circuit 340, coefficients of less orders for representing the envelope of the orthogonal transform coefficients in the orthogonal transform circuit 320 are calculated. In a a quantization circuit 350, the orthogonal transform coefficients are quantized by representing them by a pulse train while determining the position to raise (generate) a pulse using the output of the coefficient calculating circuit 340. Since the envelope of orthogonal transform coefficients is represented by the coefficients of less orders and the orthogonal transform coefficients are represented by the combination of plural numbers of pulse trains base on the coefficient, more efficient encoding is performed than before. |
