双树复小波包变换语音增强新算法

实小波包变换是语音增强中效果较好的一种算法,利用阈值的方法对小波包系数进行压缩进而重构语音信号.分析了实小波包变换的平移敏感性,以及其对语音进行增强时的缺陷.提出采用双树复小波包变换方法进行语音增强,当低通滤波器和高通滤波器对应的小波基近似为希尔伯特变换对时,该变换能大大减小实小波包变换中的平移敏感性.同时考虑小波包系数之间的相互关系,提出了重叠块复阈值算法.结果表明,算法优于传统实小波包变换及点阈值算法,尤其对含周期噪声的语音信号,双树复小波包变换算法的优势更为明显.

New method for speech enhancement based on Dual-Tree Complex Wavelet Packet Transform

Real wavelet Packet Transform(RWPT)is a better algorithm for speech enhancement,uses threshold to shrink wavelet packet coefficients and reconstruct speech signal.The property of shift sensitivity of RWPT and its disadvantages in speech enhancement is analysised,Dual-Tree Complex Wavelet Packet Transform (DTCWPT)is proposed to speech enhancement,DTCWPT can reduce shift sensitivity largely when the basis functions of low-pass filter and high-pass filter form Hilbert transform pairs.And the relationship of co...