Cracking the Code: LoRa Physical-Layer Insights and Signal Recovery under Cross-Technology Interference

Low-Power Wide-Area Networks (LPWANs) have emerged as a promising communication technology for the Internet of Things (IoT). However, frequency overlap among wireless networks using different radio technologies creates significant interference, compromising communication reliability. This challenge is particularly urgent in LoRa networks, which coexist in the 2.4 GHz ISM band with other IoT transmitters capable of transmitting at much higher power levels. In our study, we begin by providing a comprehensive understanding of the LoRa physical layer (PHY), including insights into modulation and demodulation mechanisms. Leveraging this knowledge, we successfully implemented a real-time LoRa PHY on the GNU Radio Software-Defined Radio platform. To address cross-technology interference during peak detection, we introduce a spectrum merging technique that maintains phase coherence between superimposed peaks, minimizing spectral leakage artifacts. Beyond that, our analysis actively enhances the performance of commercial LoRa devices. Furthermore, we systematically explore the interference dynamics between LoRa and IEEE 802.15.4g networks. Our rigorous investigation reveals LoRa’s ability to achieve high packet reception rates, even in the presence of strong IEEE 802.15.4g interference.