In order to study the effect of the coexistence of rain and fog on the communication performance of satellite terrestrial quantum link, the relationship between link attenuation and transmission distance and visibility was analyzed based on the attenuation model of optical quantum under the coexistence of rain and fog, and the influence of the coexistence of rain and fog on channel capacity, channel fidelity, channel survival function and channel bit error rate was studied. The findings reveal that at a visibility of 0.5 km and a transmission distance of 0.3 km, the link experiences an attenuation of$\text{1 0. 2 2 d B} \cdot \text{k m}-\text{1}$. Furthermore, at the same visibility of 0.5 km and transmission distance of 0.25 km, the channel capacities for the amplitude damped and depolarized channels are recorded as 0.41 bit$/ \mathrm{s}$and 0.29 bit/s respectively. When visibility is 0.5 km and transmission distance is 0.3 km, the survival function values of amplitude damped channel and depolarized channel are 0.901 and 0.979 respectively. At a visibility of 0.5 km and with a transmission distance of 1 km, the channel's bit error rate reaches 0.24. Consequently, the coexistence of rain and fog significantly affects the efficiency of satellite terrestrial quantum communication systems. System parameters should be adjusted adaptively according to different environmental parameters to ensure the stability and reliability of the system.
In order to study the effect of the coexistence of rain and fog on the communication performance of satellite terrestrial quantum link, the relationship between link attenuation and transmission distance and visibility was analyzed based on the attenuation model of optical quantum under the coexistence of rain and fog, and the influence of the coexistence of rain and fog on channel capacity, channel fidelity, channel survival function and channel bit error rate was studied. The findings reveal that at a visibility of 0.5 km and a transmission distance of 0.3 km, the link experiences an attenuation of1 0. 2 2 d B⋅k m−1. Furthermore, at the same visibility of 0.5 km and transmission distance of 0.25 km, the channel capacities for the amplitude damped and depolarized channels are recorded as 0.41 bit/sand 0.29 bit/s respectively. When visibility is 0.5 km and transmission distance is 0.3 km, the survival function values of amplitude damped channel and depolarized channel are 0.901 and 0.979 respectively. At a visibility of 0.5 km and with a transmission distance of 1 km, the channel's bit error rate reaches 0.24. Consequently, the coexistence of rain and fog significantly affects the efficiency of satellite terrestrial quantum communication systems. System parameters should be adjusted adaptively according to different environmental parameters to ensure the stability and reliability of the system.
To investigate the impact of rain-fog coexistence on quantum positioning performance, we analyzed-using raindropsize distribution functions and extinction coefficients-how visibility and propagation distance in such compound conditions affect photon energy, positioning error, quantum-channel fidelity, and bit-error rate. For a 10km link, the energy of a single photon drops to 1.87×10−6J when visibility is 0.7 km and to 1.59×10−6J when visibility falls to 0.6 km. While visibility decreases from 0.7 km to 0.5 km, and the photon energy is kept at 10×10−5J, the positioning error grows from 0.826 cm to 1.017 cm. Although the exact decline differs slightly among channels, the fidelity of the quantum communication channel invariably decreases as visibility worsens. At a 1 km range, the channel bit-error rate rises to 0.24 when visibility is 0.50 km and to 0.14 when it is 0.55 km. These results demonstrate that rain-fog coexistence markedly degrades quantum positioning performance. Consequently, system parameters must be adjusted in real time according to the prevailing visibility and propagation distance to maintain the stability and reliability of quantum positioning systems operating in rain-fog environments.
Quantum communication provides high security and privacy, offering effective protection against eavesdropping and decryption during information transmission. Its inherent unconditional security addresses information security issues effectively. Dust particles, as prevalent environmental factors in the atmosphere, exert negative impacts on both traditional and quantum communication. Due to the higher requirements for signal fidelity and stability in quantum communication, the impact of dust particles may be more significant. To investigate the effect of dust aerosol particles on the performance of satellite-ground quantum communication links, we established quantitative relationships between particle number concentration and transmission distance, and the link attenuation, as well as the channel capacity, system survival function, and error rate of three noise channels: amplitude damping, bit-flip, and depolarizing channels. Using Matlab, we conducted experimental simulations based on the size distribution function of dust aerosol particles and Mie scattering theory. The simulation results indicate that when the transmission distance is 6 km and the particle concentration of dust aerosols increases from20/m3to55/m3, the channel attenuation factor increases from84.35dB/kmto232dB/km. The capacity of the amplitude damping channel decreases from0.6486bit/sto0.3943bit/s, and the survival function of the amplitude damping channel decreases to 0.9059. When the particle concentration is900/m3and the transmission distance increases from 3km to 8km, the bit error rate increases from 0.03 to 0.2. The results indicate that dust aerosols have impacted various aspects of satellite-to-ground communication, each in different ways, highlighting the importance of considering their influence. Therefore, when implementing quantum communication in practice, it is essential to adjust the parameters accordingly to ensure the normal operation of communication.
In quantum satellite communication, when the optical quantum signal is transmitted between satellite and ground links, it will be affected by various natural environments.At the same time, haze has become one of the largest environmental problems in the world.Therefore, it is of great significance to study the communication performance of quantum satellites in haze atmosphere.In this paper, according to the scale distribution and vertical spatial concentration change of large aerosol haze particles, the extinction characteristic model of large aerosol haze particles and the attenuation model of atmospheric haze particle concentration and transmission height on quantum satellite ground link are established.Some important performance parameters in quantum satellite communication are analyzed for amplitude damping channel, depolarization channel and phase damping channel respectively, It includes the quantitative relationship between channel capacity, quantum fidelity, quantum bit error rate and entanglement and large aerosol haze particle concentration and transmission height.The simulation results show that with the increase of transmission distance and haze particle concentration, the channel capacity, quantum fidelity and entanglement of quantum satellite communication in different channels will decrease, and the bit error rate will increase.Therefore, the impact of large haze environment on quantum satellite communication should be fully considered in the actual process of quantum satellite communication, Adaptive adjustment of relevant parameters to ensure the normal operation of quantum satellite communication.
Abstract Soot aerosol is an important part of atmospheric aerosol, which has important influence on the propagation of quantum signal. In order to study the influence of soot aerosol on satellite-ground quantum communication, according to the size distribution parameter and extinction coefficient of the soot aerosol, the influence of the concentration of the soot aerosol particles and the transmission distance on the attenuation of the link is analyzed. The simulation experiments of channel capacity, channel fidelity and channel bit error rate (Ber) are carried out with amplitude-damped channel. The simulation results show that the soot aerosol concentration increases from 2.1×10 6 / m 3 to 3.2 10× 6 / m 3 , the link attenuation factor increases from 0.3dB/ km to 0.46dB/ km, the fidelity decreases from 0.98 to 0.97, and the bit error rate increases from 0.0087 to 0.0122 at a transmission distance of 3km . hhen the transmission distance is 6km and the particle concentration is 2.1×10 6 / m 3 , 2.7 10× 6 / m 3 and 3.9×10 6 / m 3 , the channel capacity increases from 1.078 to 1.0809, and then decreases to 1.0804. Therefore, the soot aerosol has influence on the performance of satellite-ground quantum communication, and the degree of influence is different. In order to ensure the reliability of quantum communication between satellite and ground, the parameters can be adjusted to ensure the normal transmission of quantum signal.
In order to study the communication performance and parameter analysis of the satellite-to-earth link of the quantum satellite under the condition of forming snowfall in the stratosphere, firstly, according to the distribution function and extinction characteristics of the concentric spherical ice water condensation nuclei in the stratosphere and the snowfall, according to the Mie theory, the system environment is obtained. The extinction efficiency factor establishes the relationship between the quantum signal transmission distance and link attenuation under different system environmental levels. Further studies have been done to establish the relationship between channel capacity, survival function, bit error rate, transmission distance, and system environment level under the condition of long-distance transmission of optical quantum signals at a moderate proportion of stratus cloud and snowfall. The simulation shows that as the transmission distance and environmental level increase, the link attenuation gradually increases, the channel capacity and survival function are greatly reduced, and the bit error rate increases. Therefore, when performing satellite-to-earth link communication, the relevant parameters of quantum communication should be adjusted adaptively to reduce the influence of snowfall caused by the formation of stratus clouds and improve the transmission performance of quantum communication.
Quantum satellite communication is a critical component of the global quantum communication network. This study investigates the impact of advection fog on the performance of satellite-ground quantum satellite communication. An energy decay model for optical quantum signals in the presence of advection fog is established based on the Gamma spectral distribution function of fog droplet particles and Mie scattering theory. The relationship between advection fog water content and channel establishment rate, as well as between advection fog water content and channel entanglement, are studied and simulated. The impact of advection fog on the survival function of quantum satellite communication channels is also investigated for damped amplitude channels. The simulation results show that the channel establishment rate decreases from 16.12 pairs/sec to 12.34 pairs/sec as the water content of advection fog increases from 0.28 <?TeX g⋅m−3?> to 0.83 <?TeX g⋅m−3?> . The channel entanglement decreases from 0.298 <?TeX g⋅m−3?> to 0.081 <?TeX g⋅m−3?> when the probability of the source character is 0.6, and the water content of advection fog increases from 0.125 to 0.8. The channel survival function decreases from 0.59 to 0.32 when the transmission distance is <?TeX L=6.5km?> , and the water content of advection fog increases from 0.21 <?TeX g⋅m−3?> to 0.61 <?TeX g⋅m−3?> . Advection fog can significantly impact the performance of quantum satellite communication, and appropriate adjustment strategies based on the amount of water content in the advection fog should be adopted to ensure the reliability and effectiveness of communication.