Performance Limits for Fingerprinting-Based Indoor Optical Communication Positioning Systems Exploiting Multipath Reflections

Hamid Hosseinianfar,Maite Brandt-Pearce

doi:10.1109/jphot.2020.2991472

Abstract

In this paper, we introduce an uplink optical wireless positioning system for indoor applications. This technique uses fingerprints based on the indoor optical wireless channel impulse response for localization. Exploiting the line of sight peak power (LOS), the second power peak (SPP) of the impulse response, and the delay between the LOS and SPP, we present a proof of concept design and theoretical analysis for localization employing a single fixed reference point, i.e., a photodetector (PD) on the ceiling. Adding more PDs leads to more accurate transmitter position estimation. As a benchmark, we present analytical expressions of the Cramer-Rao lower bound (CRLB) for different numbers of PDs and features. We further present closed form analytical approximations for the chosen features of the channel impulse response. Simulation results show a root mean square (RMS) positioning accuracy of 25\,cm and 5\,cm for one and four PDs, respectively, for a typical indoor room at high SNR. Numerical results verify that the derived analytic approximations closely match the simulations.

Highlights

There is currently a high demand for localization services in many applications like robotics, unmanned aerial vehicles, Internet of things applications, and self-driving cars
Multipath reflection degrades the performance of visible light communications (VLC) based localization systems, where it is often considered as a strong random noise
Most of the conventional methods that rely on strong line of sight (LOS) connections such as received signal strength (RSS), time difference of arrival (TDOA), and angle of arrival (AOA), require multiple LOS connections to estimate the location of users

Summary

Introduction

There is currently a high demand for localization services in many applications like robotics, unmanned aerial vehicles, Internet of things applications, and self-driving cars. Visible light communication (VLC) indoor localization systems are superior to alternative indoor localization techniques due to their centimeter positioning accuracy [1]–[3]. Of relying on multipath reflections in fingerprinting-map-based VLC localization. While VLC is a promising approach for localization, implementing an effective system is challenging for two crucial reasons. In a comprehensive study on the impact of multipath reflection on RSS-based localization [5], Gu et al report two to three orders of magnitude of localization accuracy degradation. These challenges lead researchers to develop new techniques specific to VLC systems and combine these approaches as hybrid techniques [6], [7]

Methods

Results

Discussion

Conclusion