GOPA: Geometrical Optics Positioning Algorithm

In this paper, we propose an accurate visible light indoor localization system for a smartphone using the commercial light-emitting diode (LED) panels which are used primarily for lighting. Each of designed lighting panel contains a space-colorcoded identifier, a matrix with a unique pattern of spatially separated colored LEDs, for labeling different positioning cells while the lighting color is kept white by balancing the number of different sets of colored LEDs. The advantage of this idea is that we do not use the time-frequency domain of visible light communication (VLC) networks resources for positioning signaling. Our positioning technique called geometrical optics positioning algorithm (GOPA) is an angle of arrival (AOA)-based geometrical algorithm on smartphones to locate the device. The front-facing camera of the smartphone is used at the receiver side to capture the image. Experimental results show robust two-dimensional (2-D) and three-dimensional (3-D) positioning. The experimental mean positioning error for 2-D positioning is 0.54 cm, in case of ignoring the tilt. The experimental mean positioning errors for 3-D positioning are respectively 1.24 cm, and 1.85 cm for ideal non-tilted and non-oriented, and non-tilted but orientated scenarios.