ESIM-OFDM-based transceiver design of a visible light communication system

Visible light communication (VLC) system has been becoming a potential technology for short-range data communication over wireless optical channel. In this paper, a real-time state-of-the-art VLC system prototype is implemented mainly based on enhanced subcarrier index modulation orthogonal frequency division multiplexing (ESIM-OFDM) modulation scheme. The prototype has been designed using NI cDAQ hardware equipment programmed in matlab/labview. In other words, the developed VLC transceiver labview model is loaded into cDAQ to perform real-time transmission of text data. The design mainly comprises VLC transmitter, VLC receiver, interfacing NI cDAQ with labview, and implementation of ESIM-OFDM. It should be noted that the direct output of ESIM-OFDM is not suitable to drive VLC transmitter circuit; therefore, the key contribution lies in making use of sigma–delta modulator to modify ESIM-OFDM output to produce constant current signal which in turn could drive VLC transmitter. The second main contribution of the work targets the luminous properties of the designed transmitter that have experimentally been characterized using a LUX meter. Finally, the last contribution of the work is the simulation carried out to analyze the performance of the proposed system with other existing VLC modulation schemes.