Implementation of Software-Defined Adaptive DCO-OFDM for Vehicular Visible Light Communication

With its high data rates and electromagnetic interference-free operation capability, visible light communication (VLC), has emerged as a potential candidate for 6G and beyond networks. In this work, we present the preliminary experimental results of our rate-adaptive OFDM vehicular VLC implemented on software-defined platform. The physical layer of the system builds upon direct current biased optical OFDM (DCO-OFDM) and supports adaptive transmission with different modulation schemes/levels including BPSK, 4-QAM, 16-QAM and 64-QAM. For switching between different modulation schemes, a feedback link with on/off keying modulation is used to send channel state information (CSI) to the OFDM transmitter. Based on the CSI, the OFDM transmitter adapts its next transmission by selecting a modulation scheme/level which maximizes the spectral efficiency while satisfying a predefined error performance target of 3.8×10
⁻³
.