面向无源物联网应用的可见光通信反向链路关键技术研究

近年来随着物联网技术的日趋成熟，越来越多的设备和场所被赋予智能并正在积极地改善我们的生活环境。但是，物联网设备的爆炸式增长使得快速大量的数据传输以及海量设备的电池管理成为极具有挑战性的问题。与此同时，可见光通信技术因为其信号源易得、不受无线电资源限制等特点，被广泛认为是解决物联网带宽问题的一个重要方案。然而，传统可见光通信技术无法满足无源物联网应用场景中低功耗和宽视角的实际需求。本项目拟就基于后向散射理念的面向无源物联网应用的可见光通信反向链路关键技术展开研究，突破传统的上下行链路对称设计，提出通过有机地结合光学逆反射材料和液晶快门产生基于透光率调制的无源反向传输媒介，研发基于编码辅助的斜率调制和最优匹配解调算法以及基于偏振光的二维角度信息差分传输技术，从信噪比换带宽以及降低信道噪声的角度提高系统性能，构建具有单一技术、低功耗、宽视角特点并适用于无源物联网应用的可见光通信反向链路技术方案。

Internet-of-Things (IoT) has been creating ambient intelligence to improve our daily life. The explosive growth of IoT devices has made rapid and massive data transmission and battery management of devices a very challenging issue. At the same time, visible light communication technology is widely considered as an important solution to solve the bandwidth problem of the Internet of Things because of its characteristics such as the ubiquitous availability of signal sources and its abundant spectrum. However, the traditional visible light communication technology cannot meet the practical requirements of low power and flexible pointing in the IoT application scenario. This project intends to study the key technologies of the visible light communication reverse link for battery-free Internet of Things applications. Different from the traditional symmetric design of uplink and downlink, we propose to organically integrate retroreflective materials and LCD shutters to build a passive visible light transmitter for backscatter communication. We also developed high-speed modulation algorithms for liquid crystal modulators and noise interference suppression techniques for multipath transmission channels. Our goal is the develop a visible light communication reserve link technology that meets the requirement of low-power and flexible pointing requirement for battery-free IoT applications.