this code describe QAM, FM, AM, PM, PSK modulation of a sound wave.

通信原理仿真实验：AM、FM调制、单双极性归零码波形及功率谱、根升余弦滚降系统功率谱密度及眼图、信源分布对AMI功率谱的影响。-Communication Theory simulation: AM, FM modulation, single and double polarity zero code waveform and power spectrum, root raised cosine roll-off system power spectral density and eye di