Reversed probabilistic shaping scheme for fiber-visible light communication converged system with Kramers-Kronig receiver.

Abstract

With the growing demand for high speed, low latency, and flexible access in 6G communication, hybrid fiber-visible light communication (VLC) systems have emerged as a promising solution by combining the capacity of optical fiber with the deployment flexibility of VLC. However, signal distortion and low signal-to-noise ratio (SNR) caused by low received optical power (ROP) in such systems pose some challenges, particularly when using direct detection. To address these issues, we demonstrate a fiber-VLC converged system that integrates a Kramers-Kronig (KK) receiver with a reversed probabilistic shaping (RPS) strategy. The proposed system enables reliable transmission over a 20-km fiber link followed by up to 4 meters of free-space VLC, achieving improved performance in terms of error vector magnitude (EVM), peak-to-average power ratio (PAPR), and normalized generalized mutual information (NGMI) under low-SNR and peak-power-constrained conditions. As the VLC free-space transmission distance increases from 0.5 to 4 meters, the system employing RPS maintains a high-performance net data rate, decreasing from 10.36 Gbps to 8.7 Gbps. To the best of our knowledge, this is the first time that KK detection combined with RPS is experimentally demonstrated in a hybrid fiber-VLC system, which indicates that RPS with a KK receiver is a viable solution for next-generation hybrid optical wireless networks.