线性相位NPR DFT滤波器组设计

Design of NPR DFT filter banks with linear phase

提出了一种具有不同分析和综合原型滤波器的线性相位过采样NPRDFT调制滤波器组的设计方法。根据滤波器组在子带混叠、系统输出混叠、系统失真三方面的要求,推导并给出了相应的设计算法。不同的分析、综合原型滤波器的使用增加了设计自由度,可以有效改善滤波器组的整体性能。另外,由于考虑了线性相位约束,滤波器组的通带平坦性约束变得更为简单,简化了设计算法。

This paper presents a new method to design oversampled linear phase Nearly Perfect Reconstruction（NPR） DFT modulated filter banks with different analysis and synthesis prototype filters.In terms of the requirements on the aliasing in the subband,aliasing in the output,and system distortion of the filter bank,the corresponding design algorithm is derived and given.Usage of the two prototype filters increases the degrees of freedom available for design and thus the proposed method can achieve better performance.Additionally,due to the linear phase constraint,the constraint on the passband flatness becomes simpler and the design algorithm is significantly simplified.