Viñals Roser, Muñoz Olga, Agustín Adrián, Vidal Josep
The Department of Signal Theory and Comunications, Universitat Politècnica de Catalunya (UPC); 08034 Barcelona, Spain.
Signal Processing Laboratory (LTS5), École Polytechnique Fédérale de Lausanne (EPFL); 1015 Lausanne, Switzerland.
Sensors (Basel). 2020 Nov 29;20(23):6836. doi: 10.3390/s20236836.
In this paper, we design linear precoders for the downlink of a visible light communication (VLC) system that simultaneously serves multiple users. Instead of using phosphor-coated white light-emitting diodes (PWLEDs), we focus on Red-Green-Blue light-emitting diodes (RGB-LEDs) that allow modulating three separate data streams on the three primary colors of the RGB-LEDs. For this system, we design a zero-forcing (ZF) precoder that maximizes the weighted sum rate for a multilevel pulse amplitude modulation (M-PAM). The precoding design in RGB-based systems presents some challenges due to the system constraints, such as the limited power, the non-negative amplitude constraints per light-emitting diode (LED), and the need to guarantee white light emission while transmitting with RGB-LEDs. For comparison purposes, we also consider the ZF design for a PWLED-based system and evaluate the performance of both a PWLED- and an RGB-based system.
在本文中，我们为同时服务多个用户的可见光通信（VLC）系统的下行链路设计线性预编码器。我们关注的是红-绿-蓝发光二极管（RGB-LED），而非使用涂有磷光体的白色发光二极管（PWLED），RGB-LED允许在其三种原色上调制三个独立的数据流。对于该系统，我们设计了一种迫零（ZF）预编码器，其能使多级脉冲幅度调制（M-PAM）的加权和速率最大化。基于RGB的系统中的预编码设计由于系统约束而面临一些挑战，例如功率受限、每个发光二极管（LED）的非负幅度约束，以及在使用RGB-LED进行传输时保证白光发射的需求。为了进行比较，我们还考虑了基于PWLED的系统的ZF设计，并评估基于PWLED和基于RGB的系统的性能。
