FPGA Implementation of OFDM-based Visible Light Communication System

Visible Light Communication (VLC) continues to attract the attention of academia and industry due to its potential as a complementary technology for wireless communication. Appropriate modulation technique becomes an important factor in supporting the realization of the VLC system. By far the most potential is the orthogonal frequency division multiplexing (OFDM)-based modulation technique. The challenge is the OFDM signal must be real and positive to be transmitted by the intensity modulation (IM) - direct detection (DD) method. Various methods are proposed and the two most used are DC-biased Optical (DCO)-OFDM and Asymmetrically Clipped Optical (ACO)-OFDM. In this paper, both schemes have been designed on Simulink Generator and successfully synthesized into Field Programmable Gate Array (FPGA). The evaluation of implemented designs was examined from the parameters of FPGA resource utilization, power consumption, and design timing. The results show that DCO-OFDM saves up to 1.11% of FPGA resource utilization compared to ACO-OFDM. Meanwhile, in terms of power consumption, DCO-OFDM requires 0.081 W, which is slightly more efficient than ACO-OFDM which consumes 0.082 W. Lastly, in terms of design timing, both systems yield zero values for total slack, indicating that the implemented design successfully met the time constraints and the systems are reliable.