1、 生成多周期线性调频信号，并对其进行频谱分析； 2、 对仿真生成的信号利用两种窗口函数进行STFT变换生成时频分析图-1, to generate multi-cycle chirp signal, and its spectrum analysis 2, the signal generated by the simulation window function using two STFT transform to generate time-frequency analysis