Indoor positioning algorithm using light- emitting diode visible light communications

This paper proposes a novel indoor positioning algorithm using visible light communications (VLC). The algorithm is implemented by preinstalled light-emitting diode illumination systems. It recovers the VLC channel features from illuminating visible light and estimates receiver locations by analytically solving the Lambertian transmission equation group. According to our research, the algorithm is able to provide positioning resolution higher than 0.5 mm, in a practical indoor environment. The performance significantly exceeds conventional indoor positioning approaches using microwaves. 1 Introduction Due to concerns over energy efficiency, a consensus has been emerging over time that light-emitting diode (LED) will be the future desired lighting source. Compared to traditional light sources, LED offers many advantages such as long life expectancy, brightness efficiency, and environmental friendliness. Moreover, as a semiconductor light-emitting device, LED is easy to modulate at relatively high rates for other than lighting applications. 1,2 The Global Positioning System (GPS) is the most popular positioning system in the world; however, its performance is substantially limited in indoor environments, because of the significant power attenuation when electromagnetic (EM) waves pass through ceilings and walls. Consequently, most existing indoor positioning approaches are based on short-range indoor wireless communication techniques. There are two categories of indoor positioning methods.