一种新的低码率语音压缩编码方案

A New Excitation Model for Linear-Prediction-Based Speech Codecs

提出一种新的基于LPC(线性预测编码 )的BSP(二项式正弦脉冲 )语音压缩编码方案 ,即根据语音产生的原理 ,以BSP作为LPC激励源 ,并在此基础上构造了BSP语音编解码器。同时推导了BSP激励参数的求取和编码方法。实验结果表明 ,BSP编解码器由于求取BSP激励参数的计算量较小 ,因此处理速度快、时延小 ,同时编码速率在低至 2 .65kbit s时 ,具有较高的合成语音质量。

We present in this paper a new binomial sine pulse (BSP) excitation signal used in linear-prediction-based speech codecs. The structure of the BSP excitation signal is actually a sine wave whose amplitude is modulated by a binomial signal. The binomial signal describes the various trends of excitation signals in a pitch period, and the pulsatance of the BSP excitation signal coincides with the vibration frequency of vocal folds. In experiments, processing is going on frame by frame and the same excitation signal is placed at every pitch excitation moment in a frame. Speech codecs based on this new BSP excitation have the advantages of low complexity and low delay. Experiment results prove that such a new speech codec can provide highly intelligible synthesized speech below 3 kbit/s.