FFT算法的基本原理是把长序列的DFT逐次分解为较短序列的DFT.按照抽取方式的不同可分为DIT-FFT(按时间抽取)和DIF-FFT(按频率抽取)算法.按照蝶形运算的构成不同可分为基2、基4、基8以及任意因子(2n,n为大于1的整数),基2、基4算法较为常-The FFT algorithm s basic principle is decomposes gradually long sequence DFT into short sequence DFT. different may divide into according to the extraction way DIT-FFT (according to time extraction) and DIF-FFT (according to frequency extraction) the algorithm. Different may divide into the base 2, base 4, bases according to the butterfly-shaped operation s constitution 8 as well as the random factor (2n, n is bigger than 1 integer), the base 2, base 4 algorithms are more common.