This is an excellent book on learning DSP for modern wireless communications and it should get you over the fundamentals [1].
There is an interesting project for open source LoRa physical layer implementation in GNU Radio. The authors had to reverse engineer the LoRa physical layer for the implementation because it is proprietary unlike the data link layer LoRaWAN part of it [2].
[1]Digital Signal Processing in Modern Communication Systems:
There is an interesting project for open source LoRa physical layer implementation in GNU Radio. The authors had to reverse engineer the LoRa physical layer for the implementation because it is proprietary unlike the data link layer LoRaWAN part of it [2].
[1]Digital Signal Processing in Modern Communication Systems:
https://www.amazon.com/Digital-Signal-Processing-Communicati...
[2]LoRa PHY based on GNU Radio:
https://www.epfl.ch/labs/tcl/resources-and-sw/lora-phy/