近年来, PM2.5大气污染日益严重,不仅影响空气质量与大气能见度,而且还会对自由空间量子光信号的传输造成影响.然而,有关PM2.5与自由空间量子通信信道参数关系的研究,迄今尚未展开.本文根据PM2.5粒度谱分布函数及其化学成分的消光份额,提出了PM2.5指数、大气湿度与自由空间量子信道衰减的关系；针对幅值阻尼信道和退极化信道,分别建立了PM2.5污染程度与信道容量、信道平均保真度、信道误码率的定量关系.仿真结果表明,当大气湿度为30%, PM2.5指数分别为50和300时,自由空间量子通信信道容量、信道平均保真度、信道误码率分别依次为0.83和0.21,0.91和0.56,0.0048和0.0192.由此可见, PM2.5污染程度对自由空间量子通信性能有显著的影响.因此,为了提高自由空间量子通信的可靠性,应根据PM2.5大气污染状况,自适应调整系统的各项参数.%In recent years, the PM2.5 air pollution has been increasingly serious, which not only affects the air quality and visibility, but also has effects on free space optical signal transmission. However, the research about the relationship between the PM2.5 air pollution and the free space quantum communication has not yet been started. To investigate this relationship, the PM2.5 distribution function and its chemical extinction should be analyzed first. According to the degree of PM2.5 atmospheric pollution and the humidity of the atmosphere, the relationships among the PM2.5 index, the humidity of the atmosphere and the channel attenuation of the free space quantum communication can then be established. According to the amplitude damping channel and the depolarizing channel, the effects of the degree of PM2.5 air pollution on channel capacity, channel average fidelity, channel bit error rate are put out and simulated finally. Simulation results show that, if the air humidity is 30%and the PM2.5 index is 50, the channel capacity, channel average fidelity and the channel bit error rate of free space quantum communication will be 0.83, 0.91 and 0.0048 respectively. While the air humidity is 30%and the PM2.5 index is 300, the above channel parameters will be respectively 0.21, 0.56 and 0.0192. Further more, the channel average fidelity has an obvious difference between the two kinds of channel, and it is also related to the probability of the value of the source characters. Thus, the degree of PM2.5 air pollution has a significant effect on the performance of free space quantum communication. And, in order to improve the reliability of quantum communication in free space, the parameters should be adjusted adaptively based on the status of PM2.5 air pollution.
展开▼
