Using CAP Modulation to Improve VLC Link with OLED Transmitter

Recently, wireless spectrum resources are tight since many bands are already occupied therefore Visible light communication (VLC) has attracted considerable interest in recent years owing to the potential to simultaneously data transmission illumination. An organic light-emitting diode (OLED) has many attractive features that outperform a conventional semiconductor light-emitting diode (LED) for visible light contact (VLC). Nowadays, optical display devices using (OLED) are already available and OLED lighting devices have also been popular in the market due to their advantages in luminous intensity and low cost. In this paper, we suggest using carrierless and phase modulation technology (CAP) to enhance and increase the spectral efficiency of the OLED in VLC communications. To ensure the best BER, the transmitter and receiver must be line-of-sight (LoS). Matlab Simulink program was used to simulate the optical communication system, where the transmitter and receiver were designed, as well as the optical channel. Both conventional and organic photodiodes were simulated and compared in the system. The results showed an improvement in the performance of the OLED and it overcame its problems due to its narrow bandwidth of 245MHz compared to the (LED) whose bandwidth is about 1.5 GHz.