各种模拟调制和数字调制的波形和频谱图，对初学者很有帮助-A variety of analog modulation and digital modulation waveform and frequency spectrum

用SystemView软件仿真AM的调制和解调过程，有具体的实验原理、过程和电路仿真图。-Modulation and demodulation process simulation software SystemView AM, there are specific experimental principles, process and circuit simulation diagram.