Space-Time-Multiplexed Multi-Image Visible Light Positioning System Exploiting Pseudo-Miller-Coding for Smart Phones

Visible light communication-based schemes utilizing LED identifiers are among the most popular candidate solutions for indoor localization applications. In this paper, we design a comprehensive imaging visible light positioning system, which exploits off-the-shelf LED lamps and commercial user equipment employing a rolling shutter aided CMOS image sensor. More specifically, we first introduce an asynchronous oversampled multi-image detection scheme inspired by the rationale of Miller coding, which efficiently solves the synchronization problem in transmissions of LED identifiers. Then, a discrete Fourier transform aided LED flicker frequency detection algorithm is detailed for robust single-image detection. Furthermore, we extend the proposed method to a space-time-multiplexing framework, which improves the overall transmission rate and solves the problem of detecting the user's moving direction. The notable advantages of the new solution are demonstrated through both practical measurements and computer simulations, exhibiting a robust transmit distance beyond three meters for continuous frames.