Time-Varying Channel Estimation for ACO-OFDM VLC Over Mobile Environment

In this paper, time-varying channel estimation for asymmetrically clipped optical orthogonal frequency division multiplexing (ACO-OFDM) based visible light communication (VLC) is provided. The performance of conventional channel estimation degrades in a high-mobility environment. The channel responses of a scattered indoor mobile environment are derived from basis functions that arise due to the Doppler effects encountered with multipath propagation. The VLC channel is approximated with the basis expansion model (BEM) in the frequency domain and time domain for both line-of-sight (LoS) and non-line-of-sight (NLoS) communication. A comprehensive simulation analysis is conducted, taking into account both the frequency domain and time domain aspects of an ACO-OFDM VLC system, with BEM-based for time-varying VLC channel. Finally, mean square error (MSE) for channel estimation and bit error rate (BER) for the system model are provided and compared with the existing works.