全相位半带滤波器及其应用

All Phase Half Band Filter and Its Application

提出一种具有频率采样特性的半带滤波器———全相位半带滤波器(APHF),这种半带滤波器,通带和阻带波纹小,过渡带陡峭,频率响应没有过冲,可以直接进行谱分解用于设计二通道完全重建正交镜像滤波器(QMF)组.针对这种半带滤波器提出了高精度谱分解方法.与传统半带滤波器谱分解设计二通道完全重建QMF组相比,QMF组的重建精度由10-3 dB提高到10-6 dB,是半带滤波器和准确重建二通道QMF组的一种设计方法.

A type of half band filter,the all phase half band filter (APHF), is proposed. It has the property of frequency sampling, i.e. response curve passes desired frequency samples. Its frequency response has very small pass-band ripple, great stop-band attenuation, sharp transition band and without overshooting whether in stop-band or pass-band. It can be directly used to design two-channel perfect reconstruction quadrature minor filter(QMF) banks by factorizing the spectrum of the APHF directly. A method is proposed to get the spectral factors of the APHF with high precision. Compared with traditional spectral factorization method of designing two-channel perfect reconstruction QMF banks, the QMF banks designed by factorizing APHF has better reconstruction precision that improved from 10^(-3) dB to 10^(-6) dB. It′s a method for designing half band filters and two-channel perfect reconstruction QMF banks.