Transmission schemes for visible light communications in multipath environments

Discrete multitone transmission (DMT) is a useful approach to cope with the dispersive nature of VLC indoor channels. In such environments, the dispersion occurs either due to the LED in combination with its driver and or the multipath propagation channel. In this paper, we consider the impact of both types of dispersions on the bit error rate performance of a DMT based Li-Fi system. However, the main goal of this work is to compare the DMT scheme results with the transmission strategies employing frequency domain equalization. Here, we distinguish between pulse-amplitude modulation (PAM), partial-response coding, single-subcarrier (SSC) modulation, and “carrier-less amplitude and phase” (CAP) modulation.