Optimal Symbol Set Selection in GSSK Visible Light Wireless Communication Systems

The optimal symbol set selection in a generalized space shift keying (GSSK) visible light communication (VLC) system is presented and validated through hardware test-bed experiments. The VLC system uses an LED array transmitter and a digital camera receiver. The proposed approach maximizes the inter-symbol Euclidean distances and minimizes the number of corresponding neighbors. The symbol search space is significantly reduced using a novel clustering property of GSSK VLC symbols. This reduced symbol set is then subjected to a symbol search tree to obtain a locally optimum symbol set. The benefits of search space reduction and local tree search are demonstrated through numerical examples. The hardware experiments, numerical simulation, and analysis results show many decibels of performance gain over random symbol set selection.