| 摘要 |
PURPOSE:To improve a signal/noise and to obtain a reproduced voice of high quality by feeding the quantization error of a coefficient which is quantized in the past back to a coefficient to be quantized when quantizing coefficients successively, and improving the relation of quantization error-to-signal electric power relation. CONSTITUTION:A voice signal x(n) is inputted from an input terminal 10 and supplied to a coefficient extraction part 31. A coefficient corrector 60 corrects the amplitude of a coefficient which is not quantized yet according to the mutual correlation function phi(i, j) between the quantization error supplied from a quantization error calculator 70 and a base signal train supplied from a coefficient extractor 31 and a coefficient (gi). A quantizer 41 quantizes and supplies coefficients supplied from the coefficient corrector 60 to the quantization error calculator 70 through an output terminal 51, and the quantization error calculator 70 calculates the quantization error of the coefficients and supplies it to the coefficient corrector 60. Consequently, a reproduction signal error is reduced greatly and the reproduction signal of high quality is obtained. |
