Design and Performance Evaluation of Large-Scale VLC-Based Indoor Positioning Systems Under Impact of Receiver Orientation

Abstract

This paper proposes a complete design, including solutions for both physical (PHY) and link layer, and evaluates the performance of large-scale indoor positioning systems (IPSs) based on visible light communications (VLC). The triangulation method based on received signal strength (RSS) technique is employed for user localization. For the sake of signal separation at the receiver, each LED's position is encoded with a unique location identification (ID) using optical orthogonal codes (OOCs). A code re-use strategy is proposed to efficiently utilize the code resource. A novel enhancement method is also proposed to improve the system performance in terms of localization accuracy taking into account the impact of receiver orientation. Simulation results show that the maximum location error increases twice under the impact of receiver orientation when the polar angle is equal to $\theta = \pi /6$ . The effectiveness of the proposed localization enhancement method in reducing the average location error is also numerically confirmed. For the link layer design, a frame design with a 12-bit ID encoded by the Golay code for error correction is proposed. A simple proof-of-concept is implemented and experiments are conducted to analyze the overall system performance in terms of operation range and ID detectability.

Keywords

• Indoor positioning system (IPS)
• visible light communications (VLC)
• receiver orientation
• optical orthogonal codes (OOCs)
• received signal strength (RSS)
• triangulation method