| 摘要 |
PURPOSE:To enable preventing deterioration when frame length is lengthened by performing quantization of a vector for only a first pitch section of a frame and transmitting when a pitch period of an input voice signal is shorter than frame length in which quantization of a vector is performed. CONSTITUTION:A pitch analyzing section 1 analyzes a pitch period tau of an input voice. A code book 2 stores code vectors every code, and a code gain giving section 4 multiplies a vector Ct (n) from the code book 2 by code gain g (n). And linear predicting analysis is performed for an input voice signal, quantization of a vector of the predicting error signal is performed and the signal is transmitted, but quantization of a vector is performed for only a first pitch section of a frame and transmitted when a pitch period of an input voice signal is shorter than frame length in which quantization of a vector is performed, and a waveform of a remaining section of a frame is found by interpolating between this waveform of quantization and a waveform of quantization of the previous frame. |
