# 3-D Localization with Multiple LEDs Lamps in OFDM-VLC system

## TL;DR

This paper presents a novel OFDM-based VLC system that integrates 3-D localization, room illumination control, and data transmission, utilizing a hybrid estimator to improve accuracy and reduce errors in indoor environments.

## Contribution

It introduces an original spatial optical OFDM methodology for LED power discrimination and a hybrid localization approach combining WAoA and RSS estimators for enhanced accuracy.

## Key findings

- Decade improvement in RMSE with reduced power noise
- Optimal clipping factor balances accuracy and transmission capacity
- Proposed architecture demonstrates robustness and efficiency

## Abstract

Visible light communication (VLC) based localization is a potential candidate for wide range indoor localization applications. In this paper, we propose a VLC architecture based on orthogonal frequency division multiplexing (OFDM) with multiple functionalities integrated in the same system, i.e., the 3- D receiver location, the control of the room illumination intensity, as well as the data transmission capability. Herein we propose an original methodology for LED power discrimination applying spatial optical OFDM (SO-OFDM) structure for position estimation. The hybrid locator initially makes a first estimate using a weighted angle-of-arrival (WAoA)-based locator which is then used as the starting point of the recursive estimator based on the strength of the received signal (RSS). Hence, the first stage is deployed to increase convergence probability, reducing the root-mean-square error (RMSE) and the number of iterations of the second stage. Also, a performance vs computational complexity comparative analysis is carried out with parameter variations of these estimators. The numerical results indicate a decade improvement in the RMSE for each two decades of decrement of power noise on the receiver photodiode. The best clipping factor is obtained through the analysis of locator accuracy and transmission capacity for each simulated system. Finally, the numerical results also demonstrate effectiveness, robustness, and efficiency of the proposed architecture.