数字频率调制又称频移键控（FSK），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。2FSK信号便是符号“1”对应于载频，而符号“0”对应于载频（与不同的另一载频）的已调波形，而且与之间的改变是瞬间完成的。 -Digital frequency modulation called frequency shift keying (FSK), binary frequency shift keying recorded as 2FSK. Digital frequency-shift keying is the carrier frequency to transmit digital information, that is, the number of messages transmitted with the control of the carrier frequency. 2FSK signal is the symbol of "1" corresponds to the carrier frequency, while the symbol "0" corresponds to the carrier frequency (with a different carrier frequency to another) and modulated waveform, but also between the change was instantaneous.