摘要
针对室内可见光通信的通照一体需求,为实现高效数据通信和调光控制相结合,在多层非对称裁剪光正交频分复用(LACO-OFDM)信号分时正负叠加调光方法的基础上,通过在LACO-OFDM信号上叠加一个经过设计的周期信号来产生叠加的LACO-OFDM(SLACO-OFDM)信号,可以在不引入额外干扰的情况下,降低多层信号的峰均功率比。再利用正负SLACO-OFDM信号按比例结合的方式来实现混合调光。分析了通信和调光约束条件下,层间功率比例因子和混合比例因子的设置方法。提出的混合SLACO-OFDM具有更小的峰均功率比,充分利用了发光二极管(LED)整个动态范围。仿真结果表明,提出的调制方法相对于传统的多层传输方式可以获得更好的误码率性能,相对于常见调光调制方式可以获得更高的频谱效率。
Objective Indoor visible light communication systems generally need to provide both communication and lighting services,and in order to meet the standard requirements for indoor lighting,indoor visible light communication systems must have brightness control(also called dimming control).Therefore,it is imperative to design indoor visible light signal modulation methods that can perform dimming control.Indoor high-speed visible light communication often uses orthogonal frequency division multiplexing(OFDM)modulation to achieve high-speed transmission,and traditional optical OFDM research mainly focuses on improving data transmission rate,which cannot effectively support dimming control,resulting in poor user experience.Therefore,dimmable OFDM modulation schemes adapted to communication-lighting integrated applications need to be designed.In OFDM dimming design,a balance between transmission efficiency and dimming capability is required.Direct current biased optical OFDM(DCO-OFDM)controls the brightness level directly by controlling the DC bias level,but it may limit and thus corrupt the signal waveform.By superimposing layered asymmetrically clipped optical OFDM(LACO-OFDM)with multiple positives and negatives,it achieves both dimming and improved spectral efficiency by using the multi-layer transmission.However,the multi-layer superposition characteristic of LACOOFDM leads to a relatively high peak-to-average-power ratio and deteriorating the bit error rate(BER)performance at specific dimming levels.Methods For the lighting demand and dimming requirement of visible light communication,this paper proposes a hybrid superimposed LACO-OFDM(HSLACO-OFDM)modulation method based on LACO-OFDM modulation.According to the principle of LACO-OFDM signal formation and subcarrier occupancy in each layer,it can be seen that after the superposition of signals in the Lth layer,there will still be some subcarriers that are not used.The superposition of the adjusted signals on these subcarriers does not interfere with the signals of
作者
任嘉伟
汪涛
徐志坚
曲晶
Ren Jiawei;Wang Tao;Xu Zhijian;Qu Jing(School of Information System Engineering,Information Engineering University,Zhengzhou 450001,Henan,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2024年第2期97-105,共9页
Chinese Journal of Lasers
基金
国家自然科学基金(62271505)。
关键词
光通信
可见光通信
调光控制
峰均功率比
混合多层调制
optical communications
visible light communication(VLC)
dimming control
peak-to-average-power ratio
hybrid multilayer modulation
