Equalisation for high-speed Visible Light Communications using white-LEDs

The performance of visible light communications (VLC) system that uses white LEDs is limited by the bandwidth of the LED emitters. In this paper we report LED equalisation techniques that can improve the data transmission rate in VLC systems significantly. Equalisation is employed in the VLC transmitter and receiver and both experiment and simulation results show a significant improvement in the OOK-NRZ data rate when compared with the unequalised devices. This increases from 15 Mbit/s to 75 Mbit/s, whilst maintaining a low bit error rate (BER).