Toward 6 Gbps real-time laser-based white visible light communication enabled by pilot-aided clock synchronization

Visible light communication (VLC) integrating illumination and data transmission has emerged as a potential candidate technology for the next-generation (B5G/6G) wireless network. In this Letter, a high-speed and real-time phosphorescent laser-based white VLC system based on quadrature amplitude modulation orthogonal frequency division multiplexing (QAM-OFDM) is demonstrated using the field programmable gate array (FPGA) with a home-made miniaturized demo board (10 × 10 cm). To compensate the transmission error caused by the frequency offset between the transceiver, a simple pilot-aided clock synchronization (PCSN) scheme with approximate harmonic mean is proposed. With the BER below the forward error correction (FEC) limit of 3.8 × 10^-3, 1.5-m/4.69-Gbps, 10-m/4.55-Gbps, and 19.6-m/4-Gbps real-time VLC links are experimentally achieved using the 16QAM-OFDM and PCSN scheme. With the help of a bit-loading scheme, the data rate of the designed white VLC system is pushed to 10 m/6 Gbps, indicating ∼31.87% capacity improvement in comparison with the fixed 16QAM format. To the best of our knowledge, this is the highest data rate in real-time white VLC systems that has ever been reported.