程序实现fSK的发射机和接收机的解调过程，包括性能分析。绘制有关的性能曲线，和波形和频谱图。还可实现BFSK，MFSK。FSK解调时候，有两种解调方法：1包络解调法，2相干解调法。-program fSK transmitters and receivers demodulation process, including performance analysis. Drawing on the performance curve, and the waveform and spectrum. But also achieve BFSK, MFSK. FSK demodulator, we have two modems : one envelope demodulation method, two coherent demodulation.