Comparative Analysis of Nonlinearity in Asymmetrically Clipped OFDM VLC Systems Using a Precoding Scheme for Sustainable Connectivity Across Modulation Orders

Visible Light Communication (VLC) has emerged as a promising technology for advancing sustainable development through eco-friendly and energy-efficient connectivity solutions. By leveraging the visible light spectrum, VLC provides a green alternative to traditional radio frequency (RF) communication, supporting high-speed data transmission while utilizing existing LED lighting infrastructure. However, challenges such as the inherent nonlinearity of LEDs and the asymmetric clipping process introduce signal distortion, which can hinder system performance. This study examines the impact of nonlinearity in Zadoff-Chu Precoded Asymmetrically Clipped Orthogonal Frequency Division Multiplexing (ACO-OFDM) on the performance of Visible Light Communication (VLC) systems across various modulation orders. It evaluates the resulting Bit Error Rate (BER) and data throughput to identify an optimal combination of modulation order and precoding scheme that balances robustness against nonlinearity with high data transmission rates. The findings reveal that Peak-to-Average Power Ratio (PAPR) is significantly reduced by using Zadoff-Chu precoding and achieving PAPR reductions of approximately 1.89 dB for BPSK and 0.92 dB for 16-QAM. This precoding technique also leads to notable improvements in BER and spectral efficiency, especially for higher modulation orders, while the moderate increase in PAPR is outweighed by the overall performance gains. These results underscore the potential of Zadoff-Chu precoding to mitigate nonlinearity effects and enhance the efficiency of VLC systems.