Patent ID: 6366881
Filing Date: 2002-04-02
Classification: G10L

Abstract:
A voice coding method comprising:the first step of adding, when a first prediction error signal dn which is a difference between an input signal xn and a predicted value yn corresponding to the input signal xn is not less than zero, one-half of a quantization step size Tn to the first prediction error signal dn to produce a second prediction error signal en, while subtracting, when the first prediction error signal dn is less than zero, one-half of the quantization step size Tn from the first prediction error signal dn to produce a second prediction error signal en; the second step of finding a code Ln on the basis of the second prediction error signal en found in the first step and the quantization step size Tn; the third step of finding a reversely quantized value qn on the basis of the code Ln found in the second step; the fourth step of finding a quantization step size Tn+1 corresponding to the subsequent input signal xn+1 on the basis of the code Ln found in the second step; and the fifth step of finding a predicted value yn+1 corresponding to the subsequent input signal xn+1 on the basis of the reversely quantized value qn found in the third step and the predicted value yn.