Optical channel decorrelation is a key aspect in designing a multi-user visible light communication system. As light-emitting diodes (LEDs) are commonly used for illumination and data transmission in such a system simultaneously, the interference between them is a major problem for suitable modulation schemes. We have proposed to position liquid-crystal (LC) matrix elements in front of the receivers in order to block unwanted light – so effectively acting as filter and reducing the interference. To do so, the appropriate pixels of the LC filter are switched either to a transmissive state or to an opaque state. The selection of the correct pixel patterns is a high-order optimization problem, which makes it challenging for classic algorithms. In this paper, we suggest applying a genetic optimization to find suitable pixel patterns. We combine this kind of receiver-side optimization with conventional convex precoding at the transmitter side in an iterative manner. The overall optimization goal is to maximize the sum rate over all users. To prove the effectiveness, we use a numeric ray-tracing simulation with different settings. Also we analyze the impact of the main parameters for the genetic algorithm.

中文翻译：

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基于液晶矩阵的 VLC MIMO 传输干扰抑制遗传优化


光通道去相关是设计多用户可见光通信系统的一个关键方面。由于发光二极管（LED）通常同时用于此类系统中的照明和数据传输，因此它们之间的干扰是合适的调制方案的主要问题。我们建议将液晶 (LC) 矩阵元件放置在接收器前面，以阻挡不需要的光，从而有效地充当滤波器并减少干扰。为此，LC 滤光片的适当像素被切换到透射状态或不透明状态。选择正确的像素模式是一个高阶优化问题，这对于经典算法来说具有挑战性。在本文中，我们建议应用遗传优化来寻找合适的像素模式。我们以迭代方式将这种接收器端优化与发送器端的传统凸预编码结合起来。总体优化目标是最大化所有用户的总速率。为了证明有效性，我们使用不同设置的数值光线追踪模拟。我们还分析了主要参数对遗传算法的影响。