3-D Localization With Multiple LEDs Lamps in OFDM-VLC System

Visible light communication (VLC)-based localization is a potential candidate for a wide range of indoor localization applications. In this paper, we propose a VLC architecture based on orthogonal frequency division multiplexing (OFDM) with multiple functionalities integrated into the same system, i.e., the 3-D receiver location, the control of the room illumination intensity, as well as the data transmission capability. In this paper, 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. Hence, the first stage is deployed to increase the convergence probability, reducing the root-mean-square error (RMSE) and the number of iterations of the second stage. Also, a performance versus computational complexity comparative analysis is carried out with the parameter variations of these estimators. The numerical results indicate a decade improvement in the RMSE for every 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.