Spectral-efficient generalized spatial modulation based hybrid dimming scheme with LACO-OFDM in VLC

Visible light communication (VLC) is regarded as one of the promising candidates to complement the conventional radio frequency communication as it can potentially perform communication and illumination simultaneously. Recently, VLC is combined with the generalized spatial modulation (GenSM) technology to improve spectral and energy efficiencies. In order to provide high-speed communication and flexible dimming control simultaneously, in this paper, a spectral-efficient GenSM-based hybrid dimming scheme with layered asymmetrically clipped optical OFDM is proposed for VLC, which combines the spatial-domain and time-domain dimming strategies. The channel capacities of the proposed scheme are analyzed and the closed-form expressions of the channel capacity are derived in both the rich scattering scenario and highly correlated scenario. According to the required illumination level, the spatial-domain and time-domain strategies are realized based on the maximization of the channel capacity. Simulation results substantiate the superior performance of the proposed dimming scheme over the state-of-art dimming schemes.