Optical Adaptive Precoding for Visible Light Communications

TL;DR

This paper introduces an optical adaptive precoding scheme for MIMO visible light communication systems that improves robustness against interference and channel uncertainties, enhancing spectral efficiency and link reliability.

Contribution

It presents a novel precoding method that exploits transmitted symbol knowledge to mitigate interference in MIMO VLC, outperforming conventional techniques.

Findings

Enhanced robustness to CSI errors and channel correlation.

Improved bit-error-rate performance with the proposed scheme.

Demonstrated superiority over conventional precoding methods.

Abstract

Multiple-input multiple-output (MIMO) techniques have recently demonstrated significant potentials in visible light communications (VLC), as they can overcome the modulation bandwidth limitation and provide substantial improvement in terms of spectral efficiency and link reliability. However, MIMO systems typically suffer from inter-channel interference, which causes severe degradation to the system performance. In this context, we propose a novel optical adaptive precoding (OAP) scheme for the downlink of MIMO VLC systems, which exploits the knowledge of transmitted symbols to enhance the effective signal-to-interference-plus-noise ratio. We also derive bit-error-rate expressions for the OAP under perfect and outdated channel state information (CSI). Our results demonstrate that the proposed scheme is more robust to both CSI error and channel correlation, compared to conventional channel inversion precoding.