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.
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.
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.
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.
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 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 study the effect of PM2.5 on the communication performance of satellite-ground quantum links, firstly, the effect of PM2.5 particle concentration on channel parameters such as quantum communication link attenuation, channel fidelity, and channel utilization was analyzed, and parametric simulations were carried out based on the PM2.5 particle concentration spectral distribution function and Mie scattering theory to obtain its extinction efficiency factor. The simulation results show that the link attenuation factor increases from 0.221 to 5.085 when the PM2.5 particle concentration increases from 10 to 230 over a transmission distance of 14km. When the transmission distance is 10 km, and the particle concentration increases from 0 to 200, the channel fidelity decreases from 1 to 0.804. When the transmission distance is 5km, and the particle concentration increases from 30 to 200, the channel utilization decreases from 0.51 to 0.36. Therefore, the impact of PM2.5 on the performance of satellite-ground quantum link communication is more significant. According to the PM2.5 concentration, corresponding adjustment strategies can be adopted to improve the reliability of the transmission system and ensure the smooth implementation of quantum communication.