Intelligent algorithms for enhancing power amplifier performance in optical OFDM systems for VLC applications

Abstract

This paper presents the design and performance evaluation of an optical OFDM system with power amplifier optimization for visible light communication (VLC)-enabled 6G wireless networks. The proposed framework addresses key challenges such as high peak-to-average power ratio (PAPR), multi-user interference, nonlinear distortion caused by power amplifiers, and optical transmission constraints. To ensure real and non-negative optical signal transmission, the system integrates intensity modulation and direct detection (IM/DD), Hermitian symmetry, and DC biasing, while successive interference cancellation (SIC) is employed for efficient multi-user reception. In addition, a low-complexity PAPR reduction technique is incorporated to mitigate amplifier nonlinearities and improve transmission reliability. Numerical results demonstrate that the BER decreases significantly with increasing SNR for all considered modulation schemes, where lower-order modulation with SIC achieves superior reliability. Furthermore, the proposed method achieves a PAPR reduction of approximately 3–5 dB compared to conventional optical OFDM techniques. The results also indicate improved spectral efficiency and throughput, reaching up to 10 bits/s/Hz and nearly 80 bits/s at 30 dB SNR. Overall, the proposed framework offers an effective trade-off between reliability, spectral efficiency, and data rate for VLC-based 6G communication systems.