Multi-input and multi-objective design for a mini-LED LCD integrated with MIMO visible light communication

Visible light communication (VLC) is promising for next-generation communication, often integrated into lighting or a display to constitute a multifunctional system. Such a system usually has a large-scale LED matrix as input and plural functions to be optimized. In contrast, current design methods for VLC are limited to very few inputs and two objectives with a clear trade-off relationship. Regarding the limitation, this study proposes a new design optimization method for an integrated display and communication (IDAC) system. The IDAC system integrates VLC into a mini-LED LCD, whose hundreds of backlight segments act as independent transmitters to form a multi-input, multi-output (MIMO) VLC system. The mini-LED backlight also enables fine local dimming for higher display contrast and lower power consumption. Thus, modulation of the LEDs simultaneously affects VLC capacity, power consumption, and image distortion. To address this multi-input and three-objective problem, we adopt the MOEA/D (multi-objective evolutionary algorithm based on decomposition) framework. Considering the large input number, we propose a uniform sampling strategy in the three-dimensional solution space for evenly distributed solutions on the Pareto front. As a result, by comparing with conventional local dimming algorithms (<i>Max, Average</i>, and <i>Square Root</i> algorithms), the proposed method exhibits the most comprehensive performance: balanced image distortion and power consumption, as well as the highest spectral efficiency for VLC. The display and VLC performances are verified on an IDAC prototype by taking photographs with a CMOS camera to observe the stripes produced by the rolling shutter effect.