Power Consumption Evaluation in High Speed Visible Light Communication Systems

With the significant increase in wireless data traffic in recent years, the scarce radio frequency (RF) spectrum can no longer guarantee the capacity needed to meet the future growth in mobile traffic demand. New applications such as virtual reality and augmented reality further increase this demand. The emergence of high speed visible light communication (VLC) offers an opportunity to mitigate the looming spectrum crisis. However, the power consumption of a VLC link due to incoherent transmission is a major concern for system designers. Only a few studies have addressed this issue. In this paper, a theoretical study on the relationship between the power consumption and the data rate of a high speed VLC link is presented. The considered VLC link is based on direct-current-biased optical orthogonal frequency division multiplexing (DCO-OFDM) and on-off keying (OOK). The effects of spatial modulation (SM) are also investigated. The presented results show that the optimal operating bandwidth can be determined for a SM DCO-OFDM system to achieve the highest power efficiency possible. The study provides a guideline to configure a VLC system in order to optimize power efficiency for different data rate requirements.