Complete Modeling of Nonlinear Distortion in OFDM-based Optical Wireless Communication
This paper presents a complete analytical framework for modeling memoryless nonlinear effects in an intensity modulation and direct detection optical wireless communication system based on orthogonal frequency division multiplexing. The theory employs the Bussgang theorem, which is widely accepted as a means to characterise the impact of nonlinear distortions on normally-distributed signals. The current work proposes a new method to generalise this approach, and it describes how a closed-form analytical expression for the system bit error rate can be obtained for an arbitrary memoryless distortion. Major distortion effects at the transmitter stage such as quantisation and nonlinearity from the light-emitting-diode are analysed. Four known orthogonal-frequency-division-multiplexing-based modulation schemes for optical communication are considered in this study: direct-current-biased optical OFDM, asymmetrically clipped optical OFDM, pulse-amplitude-modulated discrete multitone modulation, and unipolar orthogonal frequency division multiplexing.