Visible Light Positioning Using Arrays of Time-of- Flight Pixels

Visible Light Positioning (VLP) as a class of Optical Wireless Positioning (OWP) has been increasingly studied due to the massive installation of Light Emitting Diodes (LEDs) in recent years. A passive Time-of-Flight (ToF) camera can work as a receiver in VLP systems because it can demodulate the received modulated optical signals. In this work, we aim to combine VLP technology and ToF cameras to achieve unprece-dented positioning accuracy. To this end, a VLP experimental framework consisting of five LED modules modulated by a Field Programmable Gate Array (FPGA) and a passive ToF camera is constructed. A fusion algorithm is proposed and experimentally validated that combines the Angle Of Arrival (AOA) algorithm leveraging the knowledge of the lens normals of the ToF camera and the Time Difference Of Arrival (TDOA) algorithm based on the hybrid Chan/Taylor series expansion method. In the end, we demonstrate through extensive experiments that the positioning accuracy using the fusion algorithm is higher than that using a single positioning algorithm.