Exploring the effect of LED nonlinearity on the performance of layered ACO-OFDM

2020 ◽  
Vol 59 (24) ◽  
pp. 7343
Author(s):  
Mohammed Abd Elkarim ◽  
M. M. Elsherbini ◽  
Hala M. AbdelKader ◽  
Moustafa H. Aly
Keyword(s):  
Led Nonlinearity

scholarly journals An ANN-Based Adaptive Predistorter for LED Nonlinearity in Indoor Visible Light Communications

Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 948
Author(s):  
Jenn-Kaie Lain ◽  
Yan-He Chen
Keyword(s):  
Visible Light ◽  
Light Emitting Diode ◽  
Optical Power ◽  
Visible Light Communication ◽  
Universal Function ◽  
Visible Light Communications ◽  
Least Mean Square ◽  
Training Sequences ◽  
Led Nonlinearity ◽  
Electrical Source

By modulating the optical power of the light-emitting diode (LED) in accordance with the electrical source and using a photodetector to convert the corresponding optical variation back into electrical signals, visible light communication (VLC) has been developed to achieve lighting and communications simultaneously, and is now considered one of the promising technologies for handling the continuing increases in data demands, especially indoors, for next generation wireless broadband systems. During the process of electrical-to-optical conversion using LEDs in VLC, however, signal distortion occurs due to LED nonlinearity, resulting in VLC system performance degradation. Artificial neural networks (ANNs) are thought to be capable of achieving universal function approximation, which was the motivation for introducing ANN predistortion to compensate for LED nonlinearity in this paper. Without using additional training sequences, the related parameters in the proposed ANN predistorter can be adaptively updated, using a feedback replica of the original electrical source, to track the LED time-variant characteristics due to temperature variation and aging. Computer simulations and experimental implementation were carried out to evaluate and validate the performance of the proposed ANN predistorter against existing adaptive predistorter schemes, such as the normalized least mean square predistorter and the Chebyshev polynomial predistorter.

Adaptive frequency domain pre-equalization for white-LED nonlinearity in OFDM-based visible light communication systems

2015 ◽  
Vol 13 (7) ◽  
pp. 072302-72305 ◽  
Author(s):  
Ruqi Zhang Ruqi Zhang ◽  
Jianfeng Li Jianfeng Li ◽  
Zhitong Huang Zhitong Huang ◽  
Yuefeng Ji Yuefeng Ji
Keyword(s):  
Visible Light ◽  
Frequency Domain ◽  
Communication Systems ◽  
Visible Light Communication ◽  
White Led ◽  
Led Nonlinearity

scholarly journals LED Nonlinearity Estimation and Compensation in VLC Systems Using Probabilistic Bayesian Learning

2019 ◽  
Vol 9 (13) ◽  
pp. 2711 ◽  
Author(s):  
Chen Chen ◽  
Xiong Deng ◽  
Yanbing Yang ◽  
Pengfei Du ◽  
Helin Yang ◽  
...  
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Bayesian Learning ◽  
Light Emitting Diode ◽  
Visible Light Communication ◽  
Compensation Scheme ◽  
Light Emitting ◽  
Current Curve ◽  
Time Domain Averaging ◽  
Nonlinearity Estimation ◽  
Led Nonlinearity

In this paper, we propose and evaluate a novel light-emitting diode (LED) nonlinearity estimation and compensation scheme using probabilistic Bayesian learning (PBL) for spectral-efficient visible light communication (VLC) systems. The nonlinear power-current curve of the LED transmitter can be accurately estimated by exploiting PBL regression and hence the adverse effect of LED nonlinearity can be efficiently compensated. Simulation results show that, in a 80-Mbit/s orthogonal frequency division multiplexing (OFDM)-based nonlinear VLC system, comparable bit-error rate (BER) performance can be achieved by the conventional time domain averaging (TDA)-based LED nonlinearity mitigation scheme with totally 20 training symbols (TSs) and the proposed PBL-based scheme with only a single TS. Therefore, compared with the conventional TDA scheme, the proposed PBL-based scheme can substantially reduce the required training overhead and hence greatly improve the overall spectral efficiency of bandlimited VLC systems. It is also shown that the PBL-based LED nonlinearity estimation and compensation scheme is computational efficient for the implementation in practical VLC systems.

Modeling and Mitigating LED Nonlinearity using Nonlinear ARX model with Wavelet Networks

2021 ◽  
Author(s):  
Jundao Mo ◽  
Xiong Deng ◽  
Wenxiang Fan ◽  
Yinan Niu ◽  
Yixian Dong ◽  
...  
Keyword(s):  
Arx Model ◽  
Wavelet Networks ◽  
Led Nonlinearity
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