Interference Cancelation for Coexistence of LoRaWAN With Wireless Power Transfer

Low-power wide area networks (LPWANs), which realize long-distance communication with low-power consumption, are suitable for wireless sensor networks (WSNs). In particular, long-range wide area network (LoRaWAN) has been actively studied in recent years. Since wireless power transfer (WPT) charges the battery of terminals by sending high-frequency signals, it can avoid operational disruption for battery replacement and unnecessitate wiring. However, if it is not well designed, WPT may cause interference to other wireless communication systems using the same frequency band. This article proposes a simple yet effective WPT interference cancelation method, which is suitable for LoRaWAN, to take a step to move the coexistence of LPWAN and WPT forward. The proposed method estimates the initial phase of the interfering signal by utilizing the packet frame structure of LoRaWAN and removes the interfering signal from the received signal during the signal detection process. Computer simulation results show that the proposed method can achieve almost the same symbol error rate (SER) performance as the system without interference, even under WPT interference.