对信号进行频谱分析及滤波，构成不同频率的调制信号，本程序的性能已经超过其他算法，仿真效果非常好，有详细的注释，详细画出了时域和频域的相关图。- The signal spectral analysis and filtering, Constituting the modulated signals of different frequencies, This program has exceeded the performance of other algorithms, Simulation of the effect is very good, There are detailed notes, Correlation diagram shown in detail the time domain and frequency domain.