Extending the Lora modulation to add parallel channels and improve the LoRaWAN network performance

In this paper, we present a new modulation, called DLoRa, similar in principle to the conventional LoRa modulation and compatible with it in terms of bandwidth and numerology. DLoRa departs from the conventional LoRa modulation as it is using a decreasing instantaneous frequency in the chirps instead of an increasing one as for the conventional LoRa modulation. Furthermore, we describe a software environment to accurately evaluate the "isolation"of the different virtual channels created by LoRa and DLoRa when using different Spreading Factors. Our results are in agreement with the ones present in the literature for the conventional LoRa modulation. They show that it is possible to double the number of channels by simultaneously using LoRa and DLora. The higher (double) number of subchannels available is the key to improve the network level performance of LoRa based networks.