Angle of Arrival Estimation System for LoRa Technology based on Phase Detectors

In this paper, we propose a comprehensive low-power and low-cost Angle of Arrival (AoA) estimation sys-tem. The proposed system consists of a hardware architecture and an AoA estimation algorithm. The proposed hardware captures the phase values of the received signal and transmits them to the nearest LoRaWAN gateway. In the cloud, an AoA estimation algorithm will be performed, and the AoA of the received signal will be estimated. The proposed hardware is generic, and it can estimate the AoA of any received signal that is operating at a frequency below 2.7 GHz. However, we have validated its performance with LoRa signals that are operating at the 868 MHz frequency band. The experimental validation, which has been conducted in a controlled environment, reveals that the proposed system can estimate the AoA of the received signals from various azimuth angles with median and maximum estimation errors of 4 and 14 degrees, respectively.