甚低比特率小波子带语音压缩编码

Very Low Bit Rates Wavelet Subband Speech Compression Coding

本文将谐波压扩和子带编码相结合，设计了一个完整的语音编、解码系统．在这个系统中，我们采用正交小波和双正交小波构造了两组用于子带编、解码的滤波器组，使其对子带的划分与人耳对语音的分辨特性相一致，并且在不同的子带上设计了不同的量化方案，最后使得该系统对语音有极高的压缩比，同时能保持良好的客观恢复信噪比和主观重建质量．

In this paper,a speech subband coding system combined with time domain harmonic scaling algorithm has been studied.The filter banks used for splitting subband are designed by employing orthogonal and biothogonal wavelet transform,which are similar to discrimination property of human auditory.Moreover,we provide several quantization techniques at different bands.Our goal is to raise the compression ratio of speech greatly degree while preserves good objective decoding SNR and subjective qualities of reconstucted speech.