Discrete Fourier Transform (DFT) is a powerful mathematical tool to calculate signal frequency spectrum from sampled data, but it is not very suitable for the real-time processing circumstance because of its large amount of calculation.

• 离散傅里叶变换(DFT)是利用采样数据计算信号的频谱的一种数学工具,其计算量较大,难以用于在线实时频谱分析。