说明：  Simulink 实现的FM调制，载波13KHz，频偏3KHz，调制波形存为一个波形文件。FM解调采样双斜率鉴频，解调直接输出到声卡。
(Simulink implementation of the FM modulation, carrier 13KHz, offset 3KHz, modulation waveform file saved as a waveform. FM demodulation of two-slope Kam sampling frequency, demodulated output directly to the sound card.)