Experimental Demonstration of a NLOS VLP System Based on LoRa Modulation

In this work, we propose a non-line-of-sight (NLOS) visible light positioning system based on LoRa modulation. Initially, a visible light communication (VLC) subsystem based on LoRa modulation is designed to receive the transmitter's position in NLOS links. Subsequently, leveraging the NLOS channel model and the geometric relationship between light emitting diodes (LEDs) and the virtual image of the photodetector (PD), we derive the relationship between the received signal strength and the distance from LEDs to the virtual image of the PD. Through this relationship, the trilateration method is applied to calculate the position of the receiver. Experimental results demonstrate that the average positioning errors of the system are 16.27 cm and 20.97 cm when the PD height is 60 cm and 80 cm, respectively.