傅里叶变换是一种将信号从时域变换到频域的变换形式，是信号处理的重要分析工具。离散傅里叶变换（DFT）是傅里叶变换在离散系统中的表示形式。但是DFT的计算量非常大， FFT就是DFT的一种快速算法, FFT将DFT的N2 步运算减少至 ( N/2 )log2N步。-Fourier transform is a signal from the time domain to frequency domain transformation form, is an important signal processing analysis tools. Discrete Fourier Transform (DFT) is the Fourier transform in the discrete system representation. However, very large computational DFT, FFT is a fast algorithm for DFT, FFT DFT of the N2-step operation will be reduced to (N/2) log2N step.