In this talk, a hybrid dimming control scheme in both time and spatial domains to meet the illumination requirement of implementing visible light communication (VLC) into a lighting network for a spectral-and-energy efficient layered asymmetrically clipped optical (LACO) OFDM based VLC system, particularly in conjunction with the generalized spatial modulation (GenSM), is presented and compared with other conventional schemes, and its induced channel capacity is analysed in different multiple-input multiple-output scenarios to decide the optimal number of activated LEDs and their power allocations. This talk is mainly based on the work by Tengjiao Wang, Fang Yang, Ling Cheng and Jian Song "Spectral-Efficient Generalized Spatial Modulation Based Hybrid Dimming Scheme With LACO-OFDM in VLC", IEEE Access 6 (2018): 41153-41162.