Performance Analysis of Visible Light Communications with Channel Blockage Caused by Human Bodies

This work studies the impact of channel blockage caused by human bodies in visible light communications (VLC), which is one of the key wireless technologies in 6G. As operating on the optical spectra, VLC channels can be blocked by opaque objects, especially by human users themselves. This human blockage has a nonnegligible impact on the performance of VLC. The current literature mostly considers human bodies as shaped objects to evaluate the numerical performance of VLC. In this paper, the coverage probability of line-of-sight (LoS) signal-to-noise ratio (SNR) under the impact of human blockage is derived in a closed-form expression and validated against simulations. The impact of human blockage on non line-of-sight (NLoS) is also analysed in specific room environments. Results show that increasing the distance between body and device from 10cm to 30cm can nearly halve the blockage probability, from 22% to 12%. Also, a shorter separation between VLC APs can effectively mitigate the LoS SNR degradation caused by human blockage, while the NLoS SNR degradation is irrelevant to the APs' separation.