Double Sided Signal Clipping in ACO OFDM Wireless Communication Systems

S. Dimitrov, S. Sinanovic, and H. Haas, in Proc. of International Conference on Communications (ICC 2011)

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 generally results from direct current (DC) biasing and/or from physical limitations of the transmitter front-end. These include insufficient forward biasing and the maximum driving power limit of the emitter. The clipping noise can be modeled according to the Bussgang theorem and the central limit theorem (CLT) as attenuation of the subcarriers at the receiver and addition of zero-mean complex Gaussian noise. Analytical expressions for the attenuation factor and the clipping noise variance are determined in closed form and employed in the derivation of the electrical signal-to-noise ratio (SNR) at the receiver. Finally, the theoretical SNR is verified through a bit-error ratio (BER) simulation.