720-Mbps 64-QAM-OFDM SCM transmission over RGB-LED-based FSO communication system

Abstract

The paper proposes a 720 Mbps visible light communication (VLC) system using 64-QAM-OFDM signals. Transmission of signals is achieved by modulating red, green and blue (RGB) light emitting diodes (LEDs) and transmitting all three wavelengths over free space optical (FSO) channel after subcarrier multiplexing (SCM) of 64-QAM-OFDM signals on two RF carriers. The performance of the proposed scheme is evaluated for a free space distance under the effect of weak as well as strong scintillations. Data transmission with bit error rates under pre-FEC limit (3.8×10-3) is achieved up to 1.2 meters through the proposed VLC system.