数字调制信号的产生与识别。产生数字调制信号，并汇出图像，比较直观。 通过分析解调的幅度、频率、相位来判断该信号的调制类型。-Generation and identification of digital modulation signals. Generates a digital modulation signal, and export the image, intuitive. To determine the modulation type of the signal thro