LoRa is a form of “chirp spread spectrum” modulation. The “chirp” signal sweeps smoothly across specific frequency range: usually 125 kHz, 250 kHz or 500 kHz wide. How long the sweep takes ...

So by manipulating the reference IQ signal we can create amplitude modulation or phase modulation and changing phase can also create frequency modulation. In real life, you might have two stations ...

For example, in AM radio, the voltage (amplitude) of a carrier with a fixed center frequency (the station's channel) is varied (modulated) by the analog audio signal.