Reconfigurable intelligent surface for NTU campus LoRa system

Abstract

LoRa technology enables low-power and long-range communication between gateway and Internet of things (IoT) devices in a long-range wide area network (LoRaWAN). LoRa signal transmission, however, is susceptible to blind spot problem especially in a city area where there are buildings and walls block signal propagation and dramatically attenuate signal strength down to undetectable. This final year project report presents a reconfigurable intelligent surface (RIS) that can fundamentally solve such a blind spot problem for LoRaWAN. RIS reflects LoRa signal and creates a reflection path to connect the LoRa gateway and end devices, which improves signal strength of LoRa transmission. We prototyped RIS and conduct comprehensive experiments in NTU campus to evaluate the communication improvement. The results show that the signal-to-noise rate (SNR) can be improved by up to 13.25 dB. This report aims to show the implementation of the RIS-enhanced LoRa system and how feasible it is to deploy in NTU campus.