A novel analytical framework for modeling nonlinear distortions in OFDM-based optical wireless communication

This paper presents an analytical framework to determine the impact of nonlinear distortions in an optical wireless communication system that employs orthogonal frequency division multiplexing (OFDM). The presented theory applies the Bussgang theorem, which has been widely used for the analysis of nonlinear effects on normally-distributed signals. This work proposes a new method to complete the well-known OFDM analysis approach based on the Bussgang theorem and describes how a closed-form analytical solution can be obtained for an arbitrary memoryless distortion. The framework is tested in a DC-biased optical OFDM system assuming two specific examples of nonlinear distortion caused by: (a) signal quantisation, and (b) a nonlinear light emitting diode (LED) characteristic.