Excellent explanation of a whole range of radio concepts all in support of describing just how LoRa on 2.4 GHz can travel much farther than WiFi or Bluetooth on the same frequency.
Best 15 minutes you’ll spend this month.
- Frequency
- Penetration
- Modulation including AN, FM, ASK, FSK, QAM
- Noise and noise floor
- Fourier Transform
- Chirp and de-churp
- RF circuit design
- Diversity
- Open source project
- Drone control


Starting with a disclaimer, I don’t know, what follows is speculation only.
I suspect that the only requirement is that the slope of the chirp at encoding and decoding is the same.
Ultimately, it’s used to remove noise in relation to a reference level.
I haven’t had an opportunity to do the math to confirm this and I’ve bookmarked a few LoRa videos to see if they get into the mechanics, but I’m not holding my breath.
Edit: This video seems to explain things pretty well.
https://youtu.be/jHWepP1ZWTk