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

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.

Frontier Progress of Unmanned Aerial Vehicles Optical Wireless Technologies

“…On the one hand, OFDM, as a relatively mature technology and is widely used in indoor OWC systems [ 70 , 71 , 72 , 73 , 74 ]. Based on the development of OFDM technology, researchers proposed to add this technology to the UAV wireless optical system [ 75 , 76 ]. The study thinks about the effects of the log-normal distribution model and the Rayleigh distribution model on the communication system; the closed-form expression of bit error rate (BER) of communication system link is obtained by using the Gauss–Hermite integral method.…”

“…On this basis, the simulation analyzes the relationship between the beam divergence angle, symbol rate, number of subcarriers, receiving aperture size at the transmitter, and the system BER. It is determined that under the condition of weak turbulence, the laser at the transmitter can make the link error performance reach the optimal beam launch angle, and the influence of the change of turbulence intensity on the optimal beam divergence angle is relatively limited [ 75 ]. On the other hand, in the data transmission link, it is necessary to consider the actual rate that the UAV can achieve under the conditions of energy and external interference.…”

“…On the other hand, in the data transmission link, it is necessary to consider the actual rate that the UAV can achieve under the conditions of energy and external interference. Through the research of the Tsinghua research team, we know that when the UAV group increases and the total launch energy is fixed, the data transmission efficiency will increase [ 75 ]. One of the reasons for this phenomenon is because there are more drones in the drone swarm to get higher diversity gain.…”

Indoor High Precision Three-Dimensional Positioning System Based on Visible Light Communication Using Improved Hybrid Bat Algorithm

“…where R represents the responsivity of the PD and P risi is the average optical signal power received by the receiver. Currently, the horizontal normal of the transmitter and receiver was aligned, and it also was perpendicular to the ceiling [22]. However, in actual environment, it is difficult to keep the transmitter and receiver parallel.…”

Optical single carrier-interleaved frequency division multiplexing for visible light communication systems

“…In the ACO-OFDM scheme, only the odd subcarriers are used to carry data to ensure an asymmetrical time domain signal with real and positive values. As such, DCO-OFDM has a higher spectral efficiency whilst ACO-OFDM offers improved power efficiency [9,10].…”