FSK is FM mode. For example, if the center frequency is 800MHz, then 700MHz means data 0,
And 900MHz means data 1, so even if there is a dry source, the data will not be wrong.
But if the dry source is fixed, it is not much different from the central frequency, which is fatal to FSK.
So now Bluetooth and so on are all frequency hopping methods, and 3G mobile phones are more like BPSK.
QAM and other more advanced methods, so even if it is impregnable, it is not afraid.
Question: It is amplitude modulated, just like an analog signal. As long as there is interference in the center frequency, it is an error code, which is easy to understand.
PSK: Phase modulation can be understood in this way. . Theoretically, PSK and FSK have the same anti-jamming ability to clutter, but when the interference source has a certain relationship with the central frequency (for example, the interference source has a multiple relationship with the central wave rate or has a certain relationship with the central frequency after multiplying or subtracting the intermediate frequency of the receiver), it will produce error code in the receiver.