A Novel Approach to Process the Multiple Reception of Non-Orthogonal LoRa-Like Signals

LoRa is a chirp spread-spectrum modulation that operates in industrial, scientific, and medical (ISM) free bands. The modulation has been developed for low power and long-range wireless Internet of Things (IoT) communications. Operating in unlicensed bands requires connected objects to reduce their energy consumption. Thereby, it is very likely that their access to the radio channel is random, which leads to an increase in the probability of packet collisions. In this paper, we design a new receiver able to decode several IoT LoRa-Like signals simultaneously received on the same channel and with the same spreading factor which leads to destructive collisions. Based on the particular structure of the superposed received signals and the Successive Interference Cancellation (SIC) algorithm, we propose a novel approach to detect, synchronize and decode each of them iteratively.