2FSK　 调制　 解调　 系统 是基带信号调制方式的一种　　数字频率调制又称频移键控（FSK——Frequency Shift Keying），二进制频移键控记作2FSK.数字频移键控是用载波的频率来传送数字消息，即用所传送的数字消息控制载波的频率。本文是通过2PSK调制后的信号进行分析通过matlab实现(2FSK modulation and demodulation system is a digital frequency modulation, also known as Frequency Shift Keying (FSK), which is recorded as 2FSK. Digital Frequency Shift Keying (DFSK) transmits digital messages with carrier frequency, i.e. the frequency of carrier is controlled by the transmitted digital message.)