Exploring multiamplitude voltage modulation to improve spectrum efficiency in low-complexity visible-light communication  

作　　者：Xiangyu LIU Xuetao WEI Lei GUO Yejun LIU 

机构地区：[1]School of Computer Science and Engineering, Northeastern University, Shenyang 110819, China [2]School of Information Technology, University of Cincinnati, Cincinnati 45221, USA [3]School of Communication and Information Engineering, Chongqing University of Posts and Telecommunications, Chongqing 400044, China

出　　处：《Science China(Information Sciences)》2019年第8期52-70,共19页中国科学（信息科学）（英文版）

基　　金：supported in part by National Nature Science Foundation of China (Grant Nos. 61801105, 61501104, 61775033, 61771120);by Fundamental Research Funds for the Central Universities (Grant Nos. N161604004, N161608001, N171602002)

摘　　要：Owing to the recent advancements in the Internet of Things(IoT), an increasing number of IoT devices have led to frequency crowding in wireless networks. The low-complexity visible light communication(VLC) system is a promising solution for indoor frequency-crowded wireless networks owing to the ubiquity of light-emitting diodes(LEDs) and readily deployable, low-cost modulation methods. However, due to the inherent limitations of LED materials and growth of data from IoT applications, low-complexity VLC systems can barely boost the data throughput without adding complex modulations and circuits. This study aims to design and implement a spectrum-efficient, low-complexity VLC system to improve data throughput with very little cost to support indoor IoT applications. This system uses multiamplitude voltage to transmit multiple bit streams simultaneously, making it a novel system. However, it is not trivial to achieve this goal as the varying voltage can cause the LEDs to flicker. Therefore, we further propose a voltage-to-current amplifier circuit, which effectively mitigates the effects of changes in the LED’s brightness upon human eyes. Finally, we evaluate the system under different speeds, distances, and angles. Extensive experiments demonstrate promising results from the viewpoint of spectrum efficiency, throughput, bit-error rate, and user perception.Owing to the recent advancements in the Internet of Things(IoT), an increasing number of IoT devices have led to frequency crowding in wireless networks. The low-complexity visible light communication(VLC) system is a promising solution for indoor frequency-crowded wireless networks owing to the ubiquity of light-emitting diodes(LEDs) and readily deployable, low-cost modulation methods. However, due to the inherent limitations of LED materials and growth of data from IoT applications, low-complexity VLC systems can barely boost the data throughput without adding complex modulations and circuits. This study aims to design and implement a spectrum-efficient, low-complexity VLC system to improve data throughput with very little cost to support indoor IoT applications. This system uses multiamplitude voltage to transmit multiple bit streams simultaneously, making it a novel system. However, it is not trivial to achieve this goal as the varying voltage can cause the LEDs to flicker. Therefore, we further propose a voltage-to-current amplifier circuit, which effectively mitigates the effects of changes in the LED’s brightness upon human eyes. Finally, we evaluate the system under different speeds, distances, and angles. Extensive experiments demonstrate promising results from the viewpoint of spectrum efficiency, throughput, bit-error rate, and user perception.

关 键 词：VISIBLE light communication AMPLITUDE MODULATION SPECTRAL efficiency 

分 类 号：TP[自动化与计算机技术]