Pilot Assisted Channel Estimation for Asymmetrically Clipped Optical OFDM over Visible Light Channels

The Visible Light Communication(VLC) has drawn significant attention recently for wireless communication in addressing the performance limitations of wireless systems due to the scarcity of bandwidth. In VLC system, the visible lights is used not only for illuminating rooms but also for an optical data transmission. Asymmetrically clipped optical orthogonal frequency-division multiplexing (ACO-OFDM) has been proposed for VLC systems to provide optically power efficient solution in the optical domain. The estimation of wireless channel is crucial in order to detect the transmitted data coherently. In this work, different interpolation based channel estimations for comb-type pilot distribution are proposed over visible light channels. Computer simulation results have confirmed that the proposed spline and low pass interpolation based channel estimation techniques have a clear BER performance advantages compared with linear and pchip interpolation based channel estimations for higher order modulations.