Selective Multi-pulse Pulse Position Modulation for Lighting Constrained Visible Light Communications

Lighting-constrained visible light communications (VLC) can provide both high-speed wireless communications and dimming control of the lighting state of indoor environments. Here, a dimming control method based on multi-pulse pulse position modulation (MPPM) has been investigated to simultaneously achieve high-data-rate transmissions and dimming control. MPPM data is transmitted on r slots selected from the available ones. Dimming-control-based MPPM can also be realized by changing the value of r. When the dimming level changes, the data transmission rate changes, resulting in a significant degradation of the average data transmission efficiency averaged over the data transmission efficiency of each dimming stage of VR-MPPM. This paper proposes a selective VR-MPPM (SVR-MPPM) scheme to improve this average data transmission efficiency by selecting a value of r that achieves the highest possible transmission efficiency while satisfying a wide dimming range.