A TDoA-based Single-LED VLP System Assisted by Circular Photodiodes Array Receiver

Abstract

Visible Light Positioning (VLP) stands out as a promising indoor positioning technology with wide-ranging applications, such as indoor unmanned vehicles and personnel localization. However, common VLP systems typically rely on multiple LEDs as anchors, necessitating receivers to simultaneously acquire light information from at least three LED anchors. This limitation severely restricts the feasibility of VLP in scenarios where only a single LED is available. To this end, we propose a single-LED-based VLP system enabled by the circular photodiode (PD) array receiver. Benefiting from the dedicated circular photodiode (PD) array design, the receiver can figure out the phase shift information from the modulated light emitted by the anchor LED for signal Time Difference of Arrival (TDoA) estimation. Furthermore, we engineer a straightforward yet effective TDoA-based positioning algorithm to localize the receiver with a lightweight calibration scheme to mitigate the synchronization error among the PD elements on the receiver. Extensive simulations demonstrate the proposed system can achieve centimeter-level positioning accuracy, and offer 2 times accuracy improvement compared with the traditional 2-stage-weighted least square(WLS) positioning algorithms.