Analysis of a visible light communication system with QAM-OFDM modulated white LEDs using FSO

The popularity of visible light communication (VLC) has increased recently because of the advancement of LEDs and the quantity of lighting bandwidth, which enables faster and more reliable transmission. High-speed transmission via LED networks is made possible by QAM-OFDM technology, which maximizes spectral efficiency and interference robustness to improve the VLC. For the proposed work, two OFDM modulation techniques (a PSK-OFDM and a QAM-OFDM with white LED, RZ/NRZ encoding schemes, and EDFA/SOA amplifiers) are used in the design of the VLC transmitter and receiver of the FSO channel. The design and investigation make use of the OptiSystem v21 simulation tool to assess the performance of the VLC system with an emphasis on the bit error rate, extinction ratio, and signal quality criteria. The results show that the QAM-OFDM with an RZ scheme and EDFA amplifier is the more competent than PSK-OFDM, with a Q factor of 3.94, a BER of 3.71∗10 −5 , and an extinction ratio of 10.18. The proposed network has a 10–60 Gbps data throughput limit and a 10 m link range in the presence of atmospheric conditions and noise effects.