Adaptive Statistical Bayesian MMSE Channel Estimation for Visible Light Communication

Visible light communication (VLC) is considered to be one of the promising technologies for future wireless systems and has attracted an increasing number of research interests in recent years. Optical orthogonal frequency division multiplexing has been proposed for VLC systems to eliminate the multipath interference while also facilitating the frequency domain equalization. In comparison with the conventional radio frequency (RF) based wireless communications, there has been limited considerations on channel estimation (CE) for VLC, where the indoor optical wireless channel model differs from the traditional RF case. In this paper, we present a new CE algorithm for indoor downlink VLC systems, referred to as the adaptive statistical Bayesian minimum mean square error CE (AS-BMMSE-CE). Furthermore, a so-called variable statistic window (VSW) mechanism is designed for exploiting past channel information within a window of adaptively optimized size, such that the CE performance can be significantly improved. Detailed theoretical analysis is provided and verified by extensive numerical results, demonstrating the superior performance of the proposed AS-BMMSE-CE scheme.