In this paper, the electrical power requirement and spectral efficiency of multi-carrier transmission schemes for optical wireless communications (OWC) are compared in the presence of front-end-induced double-sided signal clipping. The two existing multi-carrier modulation techniques based on orthogonal frequency division multiplexing (OFDM), direct-current-biased optical OFDM (DCO-OFDM) and asymmetrically clipped optical OFDM (ACO-OFDM), are studied. The clipping noise can be modeled according to the Bussgang theorem and the central limit theorem (CLT) as attenuation of the data-carrying subcarriers and addition of zero-mean complex-valued Gaussian noise. Presented closed-form expressions for the attenuation factor and the clipping noise variance are employed in the derivation of the effective electrical signal-to-noise ratio (SNR).
- optical wireless communications
- power systems