A spectral-efficient dimming control scheme with multi-level incremental constant weight codes in visible light communication systems

As an essential requirement for visible light communication (VLC) system, dimming control has attracted increasing attentions where arbitrary brightness levels can be achieved. Conventional dimming schemes based on binary modulation are spectral inefficient. In this paper, we propose multi-level incremental constant weight codes (ML-ICWC) scheme to achieve dimming control via controlling the number of LEDs on per lighting source simultaneously. Meanwhile, the construction algorithm of the codeword set is developed accordingly to guarantee reliable data transmission. Finally, simulation results show that the proposed scheme achieves significant improvement in terms of spectral efficiency compared with existing dimming schemes under various dimming levels.