Design and Demonstration of Robust Visible Light Positioning Based on Received Signal Strength

In this article, we consider indoor visible light positioning (VLP) based on received signal strength (RSS). Under the assumption of unknown receiver coefficient, we propose a robust VLP scheme which jointly estimates the receiver position and receiver coefficient. Through mathematical derivations, the original estimation problem is equivalently transformed into the position estimation problem of maximizing the angle between the received signal vector and RSS feature vector, where the direction of RSS feature vector is shown to be a one-to-one feature characterizing the receiver position. Compared with existing schemes, the proposed VLP scheme is more robust to the variations of transmission environments, as it only requires the ratios of transmitter coefficients rather than specific values of transceiver coefficients. Besides, for implementation of the proposed scheme, we also present a method for estimating the required parameters. Experimental and simulation results demonstrate the robustness of the proposed VLP scheme. Specifically, experimental results show that the proposed VLP scheme retains a stable positioning accuracy about 4 cm in a 150 x 60 x 60 cm(3) space and about 8 cm in a 200 x 60 x 60 cm(3) space.