Adaptive Parameter Adjustment for Uplink Transmission for Multi-gateway LoRa Systems

Recently, low power wide area (LPWA) wireless technologies is one of the most popular topics in wireless communication area because of their important function of realizing Internet of Things (IoT) applications. Among all the LPWA technologies, LoRa is popular and important with low power consumption, long life-time, robustness to noise, and low deployment cost. For LoRa system, adopting multi-gateway structure can obtain diversity of gateway selection and hence improve performance. In this study, we investigate the characteristics of multigateway LoRa system and propose a novel method to dynamically select serving gateway and allocate spreading factor (SF) considering packet error rate (PER) for each end device. The proposed method reduces packet collision rate by balancing the on-air time of each SF and adjusts the SF allocation for each end device by its previous accumulated PER. From the simulation results, the proposed method can obtain about 35$\Psi_{0}$ and 29$\Psi_{0}$ improvement in bit error rate (BER) and PER, respectively, which validates the effectiveness of the proposed method.