Outage and Power Saving Analysis for Hybrid Cellular-Visible Light Communication and Direct Cellular Downlink

Visible light communications (VLC) is an emerging technology for indoor wireless networks which uses unregulated visible spectrum in the optical range. VLC may provide power saving in indoor environments as LED consumes very less power for illumination. In this paper, we analyse the performance of hybrid cellular-VLC downlink where the outdoor coverage is provided via cellular network, and the indoor coverage is provided through a VLC network. In the proposed framework, the VLC helps to communicate the information between the base-station and user by acting as a decode-and-forward relay. The relay decodes the received signal from the base station and modulates the intensity of the optical transmitter. Single transmitter is used with integrating sphere channel model which also includes both LOS and NLOS link. The indoor optical channel model has been employed to derive the expressions for outage probability of the proposed hybrid cellular-visible light downlink. The amount of power saving by hybrid cellular-visible light link with respect to direct cellular link has also been calculated.