Demonstration of a Hybrid FSO/VLC Link for the Last Mile and Last Meter Networks

In this paper, a hybrid free-space optical and visible light communication (FSO/VLC) system was experimentally demonstrated as a solution to overcome the last mile and last meter access networks bandwidth bottleneck. We evaluate the system performance of a multiband carrier-less amplitude and phase ( m -CAP) modulation scheme for a range of FSO/VLC link lengths and m -CAP parameters (i.e., the roll-off factor of the filters and a number of subcarriers) in terms of the data rate Rb (i.e., spectral efficiency). We show that for the configuration with a 1 m VLC link the \mbox{10-CAP} offers more than a 40% improvement in the measured Rb compared to 2-CAP for the same bit error rate target. The Rb penalty due to the extension of a VLC link span from 1 m to 3 m reaches to 12.6 Mb/s for the 10-textCAP scheme (i.e., ∼ 39% degradation in Rb ). To fully cover all aspects of the hybrid FSO/VLC system, we also investigate the atmospheric turbulence effect on the 500 m FSO link where Rb is decreased by 30% for the refractive index structure parameter C2n of $\mbox{2.4×10^{\minus15}m^{\minus2/3}$ } compared to a clear channel