ABSTRACT
This chapter discusses techniques on multiple-input multiple-output (MIMO) visible light communications (VLC) system which improved the speed of data communications. It discusses the use of pilot signal in reducing the peak-to-average power ratio (PAPR) of an orthogonal frequency division multiplexing (OFDM)-based intensity-modulated optical wireless communication system. The introduction of solid-state light-emitting diode (LED) lighting has attracted the attention of communications engineers worldwide, enabling the achievement of the dual functionality of room illumination while simultaneously transmitting wireless data via VLC. A Q factor analysis of the signal between single transmitter and single receiver as function of horizontal displacement beneath the center point of a transmitter was carried out, to investigate at what distance and how fast the quality of the signal degrades. The OFDM technique is attracting a lot of interest in optical wireless communications because of its resilience to multipath propagation-induced intersymbol interference (ISI), high spectral efficiency, and immunity to fluorescent light noise near digital converter (DC) region.
