Non-Linearity Effects and Predistortion in Optical OFDM Wireless Transmission Using LEDs

Date Added: Oct 2009
Format: PDF

Orthogonal Frequency Division Multiplexing (OFDM) is a promising technique to realise high-speed indoor Optical Wireless (OW) links through the exploitation of the high Peak-to-Average Power Ratio (PAPR) for Intensity Modulation (IM). However, the non-linear characteristic of a Light Emitting Diode (LED) imposes limitations on the performance. In this paper, the impact of the non-linear characteristic on bit-error performance is analyzed using a commercially available LED (OSRAM, SFH 4230). Also, the paper proposes a pre-distorter to overcome the non-linearities. The performance without compensation and after compensation is analyzed via simulations in an Additive White Gaussian Noise (AWGN) environment.