An LED modelled GFDM for optical wireless communications

The advent of Internet Of Things (IOT) has fostered Optical Wireless Communication (OWC) to fulfil the surplus data requirements of future wireless communication systems. However, these OWC systems rely on Orthogonal Frequency Division Multiplexing (OFDM) waveform variants that suffer in terms of flexibility, spectral efficiency and power efficiency. To address these problems, a DC biased Optical Generalised Frequency Division Multiplexing (DCO-GFDM) hinge upon burst transmission employing circularly rotating pulse shaping is introduced for Intensity Modulation (IM) and Direct Detection (DD) based OWC systems. Different receivers are implemented employing Root Raised Cosine (RRC) and Dirichlet pulses. The effect of inevitable non linearity distortion generated at Light Emitting Diode (LED) on the Symbol Error Rate (SER) performance of proposed waveform is compared with DC biased Optical OFDM (DCO-OFDM) utilising two generalised LED models under Additive White Gaussian Noise (AWGN) channel. The impact of LED clipping has been studied under various constraints with respect to DC-bias point, signal power, and LED dynamic range using Monte-Carlo simulations. Results shows that SER performance is matched to DCO-OFDM even under LED nonlinear distortion but with more flexibility in the waveform design, improved spectral efficiency and around 25 dB reduction in out band carrier power showing power efficiency. (C) 2019 Elsevier GmbH. All rights reserved.