Title :
Application of Expurgated PPM to Indoor Visible Light Communications—Part I: Single-User Systems
Author :
Noshad, Mohammad ; Brandt-Pearce, Maite
Author_Institution :
Charles L. Brown Dept. of Electr. & Comput. Eng., Univ. of Virginia Charlottesville, Charlottesville, VA, USA
Abstract :
Visible light communications (VLC) in indoor environments suffer from the limited bandwidth of LEDs as well as from the inter-symbol interference (ISI) imposed by multipath. In this work, transmission schemes to improve the performance of indoor optical wireless communication (OWC) systems are introduced. Expurgated pulse-position modulation (EPPM) is proposed for this application since it can provide a wide range of peak to average power ratios (PAPR) needed for dimming of the indoor illumination. A correlation decoder used at the receiver is shown to be optimal for indoor VLC systems, which are shot noise and background-light limited. Interleaving applied on EPPM in order to decrease the ISI effect in dispersive VLC channels can significantly decrease the error probability. The proposed interleaving technique makes EPPM a better modulation option compared to PPM for VLC systems or any other dispersive OWC system. An overlapped EPPM pulse technique is proposed to increase the transmission rate when bandwidth-limited white LEDs are used as sources.
Keywords :
indoor communication; intersymbol interference; light emitting diodes; light sources; light transmission; optical dispersion; optical links; optical modulation; optical noise; optical receivers; pulse position modulation; wireless LAN; wireless channels; ISI effect; LED limited bandwidth; PAPR; background-light limited effect; bandwidth-limited white LED; correlation decoder; dispersive OWC system; dispersive VLC channels; error probability; expurgated PPM; expurgated pulse-position modulation; indoor VLC systems; indoor environments; indoor illumination dimming; indoor optical wireless communication systems; indoor visible light communication; interleaving technique; intersymbol interference; light sources; modulation option; multipath; optical receiver; overlapped EPPM pulse technique; peak to average power ratios; shot noise; single-user systems; transmission rate; transmission scheme; Decoding; Dispersion; Light emitting diodes; Modulation; Optical receivers; Peak to average power ratio; Expurgated pulse position modulation (EPPM); indoor optical wireless communications; optical networks; visible light communications;
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2013.2293341
