Characteristics of Energy Detection for Carrier Sense Implemented on LPWA Modules

To enhance capabilities of an interference avoidance at the end devices, the authors theoretically and numerically investigated the characteristics of carrier sense based on energy detection, which detects target signals using an average energy in a certain period, in low-power wide-area networks (LPWANs) and their performances. Conventional studies have been conducted mainly through computer-simulation-based analyses, and studies have never been reported using actual low-power wide-area (LPWA) modules. In this study, the characteristics of the energy-detection-based carrier sense are implemented on commercially available LPWA modules, which consist of a long-range (LoRa) chip and a micro controller unit (MCU). Two types of carrier sense, that is, the energy detection and conventional peak-detection-based, are implemented on the modules to experimentally evaluate the characteristics. The evaluation results show that not only the signal processing parameters, such as the accuracy of the power, but also the performance of the RF front end of the LoRa chip is an important factor that determines the signal detection performance.