基于DFT滤波器组实现zoom—FFT算法分析

The Algorithm Analysis of Zoom-FFT Implementation based on DFT Filter banks

本文介绍了一种基于ＤＦＴ滤波器组实现ｚｏｏｍ—ＦＦＴ算法，该算法是利用ＤＦＴ滤波器组将待分析的信号带宽分解成多个子带，经过子带选择，再进行ＦＦＴ运算。分析表明：该算法运算效率高，能实现运算量和运算精度的折衷；与Ｙｉｐ级连ｚｏｏｍ—ＦＦＴ算法比较，该算法有更大的适应性，Ｙｉｐ无修正级边ｚｏｏｍ一ＦＦＴ算法是该算法的一种特例，利用基于 ＤＦＴ滤波器组实现 ｚｐｐｍ一ＦＦＴ算法可推导出 Ｙｉｐ无修正级边 ｚｏｏｍ一ＦＦＴ算法的通用修正公式；与复调制ｚｏｏｍ一ＦＦＴ算法比较，在保证同样精度的情况下，该算法运算量为复调制ｚｏｏｍ－ＦＦＴ算法运算量的１／Ｍ（Ｍ为子带细化倍数）．

A zoom-FFT implementation based on DFT filter banks is introduced In this algorithm the sig- nal bandwidth is decomposed into many sub-bands by DFT filter banks FFT is used to calculate the local spec- trum after sub-band selecting ,After analyzing and comparison it is clear this algorithm is effective and prac- tical to realize the trade-off between complexity and more adaptive than Yip cascaded zoom-FFT algorithm While reserve the same calculation precision,the complexity of this algorithm is only about 1/M (M is the zoom--tims)of normal complex modulation zoom-FFT