Quantum communication is a brand new way of communicating, in which the quantum entanglement effect is used to transmit information. Quantum communication is a new interdisciplinary subject between quantum theory and information theory. It has advantages of perfect information security and higher efficiency in transmission. The successful launch of the first quantum satellite named Micius laid an important foundation forconstructing a secure quantum communication network on a global scale. On the other hand, in the process of quantum satellite communication, the atmospheric environment near the ground will have a certain influence on the transmission of quantum signals, so the security of quantum communication is reduced. One of the influence factors is the ionospheric sporadic E layer. In the actual quantum communication environment, when the weak coherent state light source is simulated the single photon, the source energy is attenuated if the quantum signal passes through the ionosphere. On a space scale of 80-150 km off the ground, the ionospheric sporadic E layer is an irregular thin layer, in which there occurs a sharp increase of electron density under the action of wind shear. Sporadic E layer has a great influence on quantum satellite signal transmission. However, the research about the relationship between the sporadic E layer and quantum communication channel parameters has not yet conducted. To investigate the influence of the ionospheric sporadic E layer on the performance of quantum satellite communication, sporadic E layer formation process is first analyzed. And then the relationship between the free electron density and the height is obtained. After that, the model of the free electron density, the formation thickness and the link attenuation of quantum satellite is established. According to the amplitude damping channel, the quantitative relationships among free electron density and the channel capacity, entanglement fidelity, the quantum bit error rate and the secure key rate are put forward and simulated finally. Theoretical analysis and simulation results show that when the thickness is 1 km, the electron density increases from 3105 cm-1 to 27105 cm-1, the channel capacity decreases from 0.8304 to 0.1319, the entanglement fidelity decreases from 0.9386 to 0.3606, the quantum bit error rate increases from 0.0093 to 0.0769, and the secure key production rate decreases from 9.96810-5 to 1.9110-6. It can be shown that the electron density and the thickness of sporadic E layer have significant effect on the performance of quantum satellite communication. Therefore, in the process of quantum satellite communication, in order to ensure the reliability of quantum communication, based on the detection of ionosphere parameters, the various indexes of the satellite system should be adjusted adaptively.
Quantum communication is a brand new way of communicating, in which the quantum entanglement effect is used to transmit information. Quantum communication is a new interdisciplinary subject between quantum theory and information theory. It has advantages of perfect information security and higher efficiency in transmission. The successful launch of the first quantum satellite named Micius laid an important foundation forconstructing a secure quantum communication network on a global scale. On the other hand, in the process of quantum satellite communication, the atmospheric environment near the ground will have a certain influence on the transmission of quantum signals, so the security of quantum communication is reduced. One of the influence factors is the ionospheric sporadic E layer. In the actual quantum communication environment, when the weak coherent state light source is simulated the single photon, the source energy is attenuated if the quantum signal passes through the ionosphere. On a space scale of 80-150 km off the ground, the ionospheric sporadic E layer is an irregular thin layer, in which there occurs a sharp increase of electron density under the action of wind shear. Sporadic E layer has a great influence on quantum satellite signal transmission. However, the research about the relationship between the sporadic E layer and quantum communication channel parameters has not yet conducted. To investigate the influence of the ionospheric sporadic E layer on the performance of quantum satellite communication, sporadic E layer formation process is first analyzed. And then the relationship between the free electron density and the height is obtained. After that, the model of the free electron density, the formation thickness and the link attenuation of quantum satellite is established. According to the amplitude damping channel, the quantitative relationships among free electron density and the channel capacity, entanglement fidelity, the quantum bit error rate and the secure key rate are put forward and simulated finally. Theoretical analysis and simulation results show that when the thickness is 1 km, the electron density increases from 3105 cm-1 to 27105 cm-1, the channel capacity decreases from 0.8304 to 0.1319, the entanglement fidelity decreases from 0.9386 to 0.3606, the quantum bit error rate increases from 0.0093 to 0.0769, and the secure key production rate decreases from 9.96810-5 to 1.9110-6. It can be shown that the electron density and the thickness of sporadic E layer have significant effect on the performance of quantum satellite communication. Therefore, in the process of quantum satellite communication, in order to ensure the reliability of quantum communication, based on the detection of ionosphere parameters, the various indexes of the satellite system should be adjusted adaptively.
The ionosphere E layer is about 90-150km from the ground, and contains a large number of ionized free electrons, which will have a great impact on the incident light quantum signal. So far, the research on the influence of the ionospheric E layer on the capacity of satellite-to-ground quantum communication channels has not been carried out. Based on Chapman's theory, this paper establishes a satellite-to-ground quantum communication link attenuation model under different solar zenith angles with electron density and E-layer height. According to this model, the influence of the ionospheric E layer on the amplitude damping channel capacity is simulated and analyzed. The results show that with the decrease of electron density, the increase of solar zenith angle and the increase of E layer height, the attenuation increases gradually and the channel capacity decreases gradually.
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.
Quantum satellite communication is a communication method with strong security and large coverage area, and it has become a hot research topic at home and abroad. The successful launch of the quantum satellite has laid an important foundation for future integrated quantum communication. When further studying the communication performance between quantum satellite-ground links, it is found that atmospheric particulate matter has a significant impact on quantum satellite communication performance. In this paper, by analyzing the extinction characteristics of atmospheric particles, a mathematical model of particle concentration, transmission distance and satellite-earth quantum energy is established, and the influence of atmospheric particles on communication parameters, bit error rate and entanglement degree is analyzed. The simulation results show that with the increase of particle concentration, the performance indicators of quantum satellite communication are affected to a certain extent. As the concentration of particulate matter in the atmosphere continues to decrease, the energy of the optical quantum signal continues to increase, and the quantum bit error rate increases with the increase in the concentration of atmospheric particulate matter and the transmission distance. The degree of quantum entanglement decreases with the increase of the particle size of atmospheric particles, and increases with the increase of visibility. The luminosity of light quantum will decrease with the increase of transmission height and the increase of surface particle concentration. By studying the optimization and adjustment strategy of quantum signal based on fidelity quantum relay satellite, simulation ensures the feasibility of this strategy. It is observed that the research in this paper can provide the necessary theoretical reference for the development of quantum space-ground integrated communication network.
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.
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 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.