Double-Sided Signal Clipping in ACO-OFDM Wireless Communication Systems

In this paper, the impact of double-sided signal clipping on optical wireless communication (OWC) systems employing asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) is investigated. Time domain signal clipping is introduced due to biasing issues or physical limitations of the front-ends. These include insufficient forward biasing of the emitter and the maximum driving power limit of the emitter and/or the detector. The clipping noise can be modeled according to the Bussgang theorem and the central limit theorem as attenuation of the subcarriers at the receiver and addition of zero-mean complex Gaussian noise. The attenuation factor and the clipping noise variance are determined semi-analytically and employed in the derivation of the signal-to-noise ratio (SNR) at the receiver. Finally, the theoretical SNR is verified through a bit-error ratio (BER) simulation.