A Predictive Phase Vector Quantization Method in WI Speech Coding
一种用于WI语音编码的相位预测式矢量量化方法

In traditional low bit-rate speech coding,considering that ears are not sensitive to phase information,the phase information is often neglected,and this will result in coarse and harsh speech quality,and it even may lead to inflection in pitch. In order to obtain a high-quality speech codec,the phase information of speech should be included in codec. In this paper,the phase redundancy is reduced further based on the dispersion phase vector quantization method. In the waveform interpolation(WI) speech coding model,the difference of SEW's phase spectra of conjoint frames is quantized using predictive vector quantization. The result of this scheme reveals that the speech quality is improved,and its naturalness and articulation are increased greatly. Subjective A/B listening test indicates that the reconstructed speech's quality of this method is better than that of fixed phase with 4-6 bit. Compared with the dispersion phase vector quantization method,the synthesis speech is slightly improved for female speakers.