基于谱分解技术的两通道因果稳定IIR滤波器组的设计(英文)

Design of two-channel causal-stable IIR filter banks byspectral factorization

提出一种新的两通道因果稳定IIR滤波器组的设计方法.首先基于所定义的一种余弦滚降IIR滤波器,两通道滤波器组所要求的平坦条件完全被满足;其次该方法是依赖于分析滤波器的功率谱特性,而不是该滤波器的幅度频率特性来设计滤波器组.IIR滤波器的设计问题可转化成一个准凸问题,采用凸优化算法来求解;然后对所得优化解进行谱分解,得到目标滤波器组.该滤波器组具有合理的完全重构误差,并且其多相因子的分母相同,简化了完全重构条件.采用该滤波器组作为约束非线性优化法的有效初值,进一步优化得到完全重构2通道IIR滤波器组.

A new method was proposed for designing two-channel filter banks （FBs） with causal- stable IIR filters. By using IIR filters with a cosine-rolloff transition band, the flatness condition required for two-channel NPR FB was automatically satisfied. Instead of designing the frequency magnitude responses of the analysis filters, the power spectra of the desired filters were designed by solving a quasi-convex problem. When the solution was found, the analysis filters desired can be obtained by spectral factorization. The polyphase components of the analysis filters were assumed to have an identical denominator to simplify the PR condition. Two-channel NPR IIR FB so obtained has a reasonably low reconstruction error and can be employed as the initial guess to constrained nonlinear optimization software for designing the PR IIR FB.