Passive visible light positioning systems: an overview

Localization is one of the key applications of visible light communication (VLC) using which sub-centimeter level positioning accuracy is possible. Many visible light-based positioning (VLP) systems have been designed by industry and the research community. Their commercial viability is hampered by the requirement of significant changes in the deployed lighting infrastructure, resulting in a prohibitive increase in the cost and overhead of deployment. In this paper, we review passive VLP systems an emerging paradigm that offers hope to overcome this challenge and thus can catalyze commercial adoption of a new wave of VLP systems. Unlike active systems, passive ones provide unprecedented flexibility and can enable new potential applications and scenarios such as ability to track users not carrying photosensors. Both natural light sources e.g., sunlight and artificial man-made sources can be used to transmit location information. This paper provides a taxonomy of recently proposed passive VLP systems which is supported by several examples from the recent research literature. A comparative performance of these systems based on factors like accuracy and infrastructure changes is provided along with their limitations.