A 3D Geometric Channel Modeling Method for Unmanned Aerial Vehicles

Abstract

The present invention discloses a method for three-dimensional geometric channel modeling of an unmanned aerial vehicle, belonging to the technical field of wireless communication, including: obtaining the distance relationship among the unmanned aerial vehicle, the double intelligent reflecting surface, and the mobile receiver according to the three-dimensional geometric model of the unmanned aerial vehicle; obtaining the complex channel gain of the multipath components according to the distance relationship among the unmanned aerial vehicle, the double intelligent reflecting surface, and the mobile receiver; and obtaining the impact of the double intelligent reflecting surface on the three-dimensional geometric channel characteristics of the unmanned aerial vehicle by obtaining the space-time correlation function of the double intelligent reflecting surface-assisted unmanned aerial vehicle based on the complex channel gain of the multipath components. The present invention constructs a three-dimensional geometric model based on the double intelligent reflecting surface-assisted unmanned aerial vehicle, analyzes according to the correlation function, and obtains the impacts of the number of reflecting units, the deflection angle of the double intelligent reflecting surface, and the height of the unmanned aerial vehicle on the unmanned aerial vehicle channel, which is beneficial to studying the impact of the double intelligent reflecting surface on the statistical characteristics of the unmanned aerial vehicle channel.

Description

Technical Field

[0001] The present invention relates to a method for three-dimensional geometric channel modeling of an unmanned aerial vehicle, belonging to the technical field of wireless communication. Background Art

[0002] In recent years, due to the reduction in the manufacturing and cost of Unmanned Aerial Vehicle (UAV) technology, UAV-assisted communication has attracted great interest in the industry and academia. The UAV relay communication system is a communication system with UAVs as mobile relays. With its high mobility, it has the advantages of long transmission distance, convenient deployment, flexibility, wide coverage, rapid system architecture, and high economic benefits. The realization of high-speed wireless communication by UAVs will play an important role in future communication systems. In the initial deployment, UAVs worked alone without the integration of any communication technology or Internet of Things technology. As human requirements began to increase, UAVs have integrated various technologies for data transmission using wireless networks. To significantly enhance data transmission of UAVs in outdoor scenarios, various communication technologies and techniques have been applied. Considering the convenience of deploying UAVs, cellular network operators have proposed using UAVs on-site to enhance network connectivity and area coverage during peak loads. As mentioned above, UAVs offer great advantages in terms of coverage area, data collection, connection between devices, ease of deployment, and precise monitoring.

[0003] In traditional mobile communication, the propagation environment between a UAV and a receiver is uncontrollable, which will affect the performance of the system. By using a Reconfigurable Intelligent Surface (RIS) with adjustable reflection phase, the communication scenario can be shaped into an ideal form to improve communication quality. As a multidisciplinary fusion technology, RIS provides important additional functions for any network or device, such as increasing signal capacity and channel gain, low cost, easy to deploy on any type of surface, and most importantly, RIS supports large-scale device connection. In existing literature, there are studies showing that RIS has the ability to eliminate the Doppler effect and multipath fading. However, due to the high-speed movement characteristics of UAVs, the UAV channel is a non-stationary process. Therefore, the RIS technology cannot be directly applied to the UAV communication scenario. There are studies considering the impact of the UAV path on the performance of the RIS-assisted UAV communication system, but the consideration of the number of intelligent reflection units is ignored. There are also literature studies on the broadband non-stationary random channel model of the intelligent reflection surface-assisted MIMO communication system, which considers the impact of the intelligent reflection surface on the channel statistical characteristics, but this model ignores the consideration of the reflection phase of the intelligent reflection units. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a three-dimensional geometric channel modeling method for unmanned aerial vehicles (UAVs), taking into account the influencing factors of dual intelligent reflecting surfaces on the UAV channel during air-to-ground communication, which is conducive to studying the impact of dual intelligent reflecting surfaces on the statistical characteristics of the UAV channel.

[0005] To achieve the above object / To solve the above technical problems, the present invention is implemented by the following technical solution: A three-dimensional geometric channel modeling method for UAVs, comprising:

[0006] According to the three-dimensional geometric model of the UAV, obtain the distance relationships among the UAV, the dual intelligent reflecting surfaces, and the mobile receiver;

[0007] According to the distance relationships among the UAV, the dual intelligent reflecting surfaces, and the mobile receiver, obtain the complex channel gains of the multipath components;

[0008] According to the complex channel gains of the multipath components, obtain the spatio-temporal correlation function of the UAV assisted by the dual intelligent reflecting surfaces, and through correlation analysis, obtain the influence of the dual intelligent reflecting surfaces on the three-dimensional geometric channel characteristics of the UAV.

[0009] Furthermore, before obtaining the distance relationships among the UAV, the dual intelligent reflecting surfaces, and the mobile receiver, construct a three-dimensional geometric model of the UAV assisted by the dual intelligent reflecting surfaces;

[0010] The three-dimensional geometric model of the UAV assisted by the dual intelligent reflecting surfaces includes a UAV in the air, a mobile receiver on the ground, an intelligent reflecting surface RIS1 deployed near the UAV and the mobile receiver, an intelligent reflecting surface RIS2, a scattering cluster Cluster1 located between the UAV and the mobile receiver, and a scattering cluster Cluster2 located between the intelligent reflecting surface RIS1 and the intelligent reflecting surface RIS2.

[0011] Even further, the method for obtaining the distance relationships among the UAV, the dual intelligent reflecting surfaces, and the mobile receiver according to the three-dimensional geometric model of the UAV includes:

[0012] The coordinates of the centers of the intelligent reflecting surface RIS1, the intelligent reflecting surface RIS2, the scattering cluster Cluster1, and the scattering cluster Cluster2 are respectively (x RIS1 , y RIS1 , z RIS1 ), (x RIS2 , y RIS2 , z RIS2 ), (x c1 , y c1 , z c1 ), and (x c2 , y c2 , z c2 );

[0013] The distance from the p-th antenna of the UAV transmitter to the (m x1 , m z1 )-th unit in the intelligent reflecting surface RIS1 is d p , (m x1 , m z1 ), and the calculation formula is as follows:

[0014]

[0015] The distance from the q-th antenna of the mobile receiver to the (m x1 , m z1 )-th unit in the intelligent reflecting surface RIS1 is d q , (m x1 , m z1 ), and the calculation formula is as follows:

[0016]

[0017] The distance from the p-th antenna of the UAV transmitter to the (m x2 , m z2 )-th unit in the intelligent reflecting surface RIS2 is d p , (m x2 , m z2 ), and the calculation formula is as follows:

[0018]

[0019]

[0020] The distance from the q-th antenna of the mobile receiver to the (m x2 , m z2 )-th unit in the intelligent reflecting surface RIS2 is The calculation formula is as follows:

[0021]

[0022] The distance from the (m x1 , m z1 )-th unit in the intelligent reflecting surface RIS1 to the (m x2 , m z2 )-th unit in the intelligent reflecting surface RIS2 The calculation formula is as follows:

[0023]

[0024] The distance from the p-th antenna of the UAV transmitter to the scattering cluster Cluster1 The calculation formula is as follows:

[0025]

[0026] The distance from the q-th antenna at the receiving end of the mobile receiver to the scattering cluster Cluster1 The calculation formula is as follows:

[0027]

[0028] The distance from the scattering cluster Cluster2 to the (m x1 , m z1 )-th unit in the intelligent reflecting surface RIS1 is The calculation formula is as follows:

[0029]

[0030] The distance from the scattering cluster Cluster2 to the (m x2 , m z2 )-th unit in the intelligent reflecting surface RIS2 is The calculation formula is as follows:

[0031]

[0032] Where:

[0033] P represents the number of antennas at the transmitting end of the UAV, and Q represents the number of antennas at the receiving end of the mobile receiver;

[0034] p represents the p-th antenna at the transmitting end of the UAV, and q represents the q-th antenna at the receiving end of the mobile receiver;

[0035] d0 represents the lateral distance between the center of the antenna at the transmitting end of the UAV and the center of the antenna at the receiving end of the mobile receiver;

[0036] θ RIS1 is the rotation angle of the intelligent reflecting surface RIS1 relative to the x-axis;

[0037] δ T is the distance between two adjacent antennas at the transmitting end of the UAV;

[0038] ψ T is the direction of the transmitting antenna array at the transmitting end of the UAV;

[0039] d x1 and d z1 are the horizontal and vertical sizes of each unit in the intelligent reflecting surface RIS1

[0040] M x1 is the total number of units arranged horizontally in the intelligent reflecting surface RIS1, and M x2 is the total number of units arranged horizontally in the intelligent reflecting surface RIS2;

[0041] M z1 is the total number of cells arranged vertically in the intelligent reflecting surface RIS1, M z2 is the total number of cells arranged vertically in the intelligent reflecting surface RIS2;

[0042] h0 is the altitude at which the UAV flies;

[0043] θ RIS2 is the rotation angle of the intelligent reflecting surface RIS2 with respect to the x-axis;

[0044] δ R is the distance between two adjacent antennas at the receiving end of the mobile receiver;

[0045] ψ R is the direction of the antenna array at the receiving end of the mobile receiver;

[0046] d x2 and d z2 are the horizontal and vertical sizes of each cell in the intelligent reflecting surface RIS2;

[0047] m x1p is the distance from the p-th antenna at the transmitting end of the UAV to the m x1 -th cell in the intelligent reflecting surface RIS1;

[0048] m z1p is the distance from the p-th antenna at the transmitting end of the UAV to the m z1 -th cell in the intelligent reflecting surface RIS1;

[0049] m x1q is the distance from the q-th antenna at the receiving end of the mobile receiver to the m x1 -th cell in the intelligent reflecting surface RIS1;

[0050] m z1q is the distance from the q-th antenna at the receiving end of the mobile receiver to the m z1 -th cell in the intelligent reflecting surface RIS1

[0051] m x1c2 is the distance from the m x1 -th cell in the intelligent reflecting surface RIS1 to the scattering cluster Cluster2;

[0052] m z1c2 is the distance from the m zl -th cell in the intelligent reflecting surface RIS1 to the scattering cluster Cluster2;

[0053] m x2p is the distance from the p-th antenna at the transmitting end of the UAV to the m x2 -th cell in the intelligent reflecting surface RIS2;

[0054] m z2p is the distance from the p-th antenna of the UAV transmitter to the m-th unit of the intelligent reflecting surface RIS2; z2 unit.

[0055] m x2q is the distance from the q-th antenna of the mobile receiver to the m-th unit in the intelligent reflecting surface RIS2; x2 unit.

[0056] m z2q is the distance from the q-th antenna of the mobile receiver to the m-th unit in the intelligent reflecting surface RIS2; z2 unit to.

[0057] m x2c2 is the distance from the m-th unit in the intelligent reflecting surface RIS2 to the scattering cluster Cluster2; x2 unit.

[0058] m z2c2 is the distance from the m-th unit in the intelligent reflecting surface RIS2 to the scattering cluster Cluster2; z2 unit.

[0059] Furthermore, the channel gain of the i-th multipath component is:

[0060]

[0061] where h pq (t) represents the complex channel gain of the multipath component between the p-th antenna of the UAV transmitter and the q-th antenna of the mobile receiver, and t represents the time variable;

[0062] represents the complex channel gain of the LoS component between the p-th antenna of the UAV transmitter passing through the intelligent reflecting surface RIS1 and the q-th antenna of the mobile receiver;

[0063] represents the complex channel gain of the LoS component between the p-th antenna of the UAV transmitter passing through the intelligent reflecting surface RIS2 and the q-th antenna of the mobile receiver;

[0064] represents the complex channel gain of the LoS component between the p-th antenna of the UAV transmitter passing through the intelligent reflecting surface RIS1 and the intelligent reflecting surface RIS2 and the q-th antenna of the mobile receiver;

[0065] represents the complex channel gain of the NLoS component between the p-th antenna of the UAV transmitter passing through the scattering cluster Cluster1 and the q-th antenna of the mobile receiver;

[0066] Denotes the complex channel gain of the LoS component between the p-th antenna of the UAV transmitter and the q-th antenna of the mobile receiver via the intelligent reflecting surface RIS1, the scattering cluster Cluster2, and the intelligent reflecting surface RIS2.

[0067] Furthermore, the complex channel gain of the multipath component between the p-th antenna of the UAV transmitter and the q-th antenna of the mobile receiver is calculated as follows:

[0068]

[0069] The complex channel gain of the LoS component between the p-th antenna of the UAV transmitter and the q-th antenna of the mobile receiver via the intelligent reflecting surface RIS1 is calculated as follows:

[0070]

[0071]

[0072] The complex channel gain of the LoS component between the p-th antenna of the UAV transmitter and the q-th antenna of the mobile receiver via the intelligent reflecting surface RIS2 is calculated as follows:

[0073]

[0074] The complex channel gain of the NLoS component between the p-th antenna of the UAV transmitter and the q-th antenna of the mobile receiver via the scattering cluster Cluster1 is calculated as follows:

[0075]

[0076]

[0077] The complex channel gain of the LoS component between the p-th antenna of the UAV transmitter and the q-th antenna of the mobile receiver via the intelligent reflecting surface RIS1, the scattering cluster Cluster2, and the intelligent reflecting surface RIS2 is calculated as follows:

[0078]

[0079] Where:

[0080] is the distance between the p-th antenna of the UAV transmitter and the (m x1 , m z1 )-th unit in the intelligent reflecting surface RIS1;

[0081] The distance from the q-th antenna at the receiving end of the mobile receiver to the (m x1 , m z1 )-th unit in the intelligent reflecting surface RIS1 is;

[0082] The distance from the p-th antenna at the transmitting end of the unmanned aerial vehicle to the (m x2 , m z2 )-th unit in the intelligent reflecting surface RIS2;

[0083] The distance from the q-th antenna at the receiving end of the mobile receiver to the (m x2 , m z2 )-th unit in the intelligent reflecting surface RIS2;

[0084] The distance from the (m x1 , m z1 )-th unit in the intelligent reflecting surface RIS1 to the (m x2 , m z2 )-th unit in the intelligent reflecting surface RIS2;

[0085] The distance from the p-th antenna at the transmitting end of the unmanned aerial vehicle to the scattering cluster Cluster1;

[0086] The distance from the q-th antenna at the receiving end of the mobile receiver to the scattering cluster Cluster1;

[0087] The distance from the scattering cluster Cluster2 to the (m x1 , m z1 )-th unit in the intelligent reflecting surface RIS1;

[0088] The distance from the scattering cluster Cluster2 to the (m x2 , m z2 )-th unit in the intelligent reflecting surface RIS2;

[0089] fc is the carrier frequency, K is the Rice factor, t is the motion time, c is the speed of light, and λ is the carrier wavelength;

[0090] η RIS1 represents the energy correlation coefficient from the transmitting end of the unmanned aerial vehicle to the receiving end of the mobile receiver through the intelligent reflecting surface RIS1;

[0091] v T is the moving speed of the unmanned aerial vehicle, and v R is the moving speed of the mobile receiver;

[0092] α T，RIS1 is the departure azimuth angle of the UAV transmitter to the intelligent reflecting surface RIS1; β T，RIS1 is the departure elevation angle of the UAV transmitter to the intelligent reflecting surface RIS1; α R，RIS1 is the arrival azimuth angle of the intelligent reflecting surface RIS1 to the receiving end of the mobile receiver;

[0093] β T，RIS1 is the arrival elevation angle of the intelligent reflecting surface RIS1 to the receiving end of the mobile receiver; η T is the angle in the elevation direction of the UAV's movement, γ T is the angle in the azimuth direction of the UAV's movement;

[0094] η R is the angle of the movement direction of the mobile receiver;

[0095] η RIS2 is the energy correlation coefficient of the UAV transmitter passing through the intelligent reflecting surface RIS2 to the receiving end of the mobile receiver;

[0096] α T，RIS2 is the departure azimuth angle of the UAV transmitter to the intelligent reflecting surface RIS2;

[0097] β T，RIS2 is the departure elevation angle of the UAV transmitter to the intelligent reflecting surface RIS2;

[0098] α R，RIS2 is the arrival azimuth angle of the intelligent reflecting surface RIS2 to the receiving end of the mobile receiver, β R，RIS2 is the arrival elevation angle of the intelligent reflecting surface RIS2 to the receiving end of the mobile receiver, η RIs1，RIS2 is the energy correlation coefficient of the UAV transmitter passing through the intelligent reflecting surface RIS1 and the intelligent reflecting surface RIS2 to the receiving end of the mobile receiver;

[0099] φ0 is random and represents the NLOS initial phase;

[0100] α T，c1 is the departure azimuth angle of the UAV to the scattering cluster Cluster1;

[0101] β T，c1 is the departure elevation angle of the UAV to the scattering cluster Cluster1;

[0102] α R，c1 is the arrival azimuth angle of the scattering cluster Cluster1 to the receiving end of the mobile receiver;

[0103] β R，c1 is the arrival elevation angle of the scattering cluster Cluster1 to the receiving end of the mobile receiver;

[0104] α T，c2 is the departure azimuth angle of the intelligent reflecting surface RIS1 to the scattering cluster Cluster2;

[0105] β T，c2 is the departure elevation angle of the intelligent reflecting surface RIS1 to the scattering cluster Cluster2;

[0106] α R，c2 is the arrival azimuth angle of the scattering cluster Cluster2 to the intelligent reflecting surface RIS2;

[0107] β R，c2 is the arrival elevation angle of the scattering cluster Cluster2 to the intelligent reflecting surface RIS2.

[0108] Furthermore, the spatio-temporal correlation function of the dual-intelligent-reflecting-surface-assisted UAV is as follows:

[0109]

[0110]

[0111] where: ()* represents the complex conjugate operation;

[0112] E[·] represents the expectation operation;

[0113] Δt represents the time difference;

[0114] represents the spatio-temporal correlation of the propagation link through the intelligent reflecting surface RIS1;

[0115] represents the spatio-temporal correlation of the propagation link through the intelligent reflecting surface RIS2;

[0116] represents the spatio-temporal correlation of the propagation link through the intelligent reflecting surface RIS1 and the intelligent reflecting surface RIS2;

[0117] represents the spatio-temporal correlation of the propagation link through the scattering cluster Cluster1;

[0118] represents the spatio-temporal correlation of the propagation link through the intelligent reflecting surface RIS1, the intelligent reflecting surface RIS2, and the scattering cluster Cluster2.

[0119] Furthermore, the spatio-temporal correlation (Δt) formula of the propagation link through the intelligent reflecting surface RIS1 is:

[0120]

[0121] The spatio-temporal correlation of the propagation link passing through the intelligent reflecting surface RIS2 The formula is:

[0122]

[0123]

[0124] The spatio-temporal correlation of the propagation link passing through the intelligent reflecting surface RIS1 and the intelligent reflecting surface RIS2 The formula is:

[0125]

[0126] The spatio-temporal correlation of the propagation link passing through the scattering cluster Cluster1 The formula is:

[0127]

[0128] The spatio-temporal correlation of the propagation link passing through the intelligent reflecting surface RIS1, the intelligent reflecting surface RIS2, and the scattering cluster Cluster2 The formula is:

[0129]

[0130]

[0131] Where, M x1 is the total number of units arranged horizontally in the intelligent reflecting surface RIS1, and M x2 is the total number of units arranged horizontally in the intelligent reflecting surface RIS2;

[0132] M z1 is the total number of units arranged vertically in the intelligent reflecting surface RIS1, and M z2 is the total number of units arranged vertically in the intelligent reflecting surface RIS2;

[0133] p′ represents the p′-th antenna, and q’ represents the q′-th antenna;

[0134] represents the distance from the p′-th antenna to the (m x1 , m z1 )-th unit in the intelligent reflecting surface RIS1;

[0135] represents the distance from the q′-th antenna to the (m xl , m z1 )-th unit in the intelligent reflecting surface RIS1;

[0136] represents the distance from the p'-th antenna to the (m x2 , m z2 )-th unit in the intelligent reflecting surface RIS2;

[0137] represents the distance from the q'-th antenna to the (m x2 , m z2 )-th unit in the intelligent reflecting surface RIS2;

[0138] d p’c1 represents the distance from the p'-th antenna to the scattering cluster Cluster1;

[0139] d q’c1 represents the distance from the q'-th antenna to the scattering cluster Cluster1;

[0140] fc is the carrier frequency, K is the Rice factor, t is the motion time, c is the speed of light, and λ is the carrier wavelength;

[0141] η RIS1 represents the energy correlation coefficient from the UAV transmitter to the mobile receiver through the intelligent reflecting surface RIS1;

[0142] v T is the UAV moving speed, and v R is the mobile receiver moving speed;

[0143] α T,RIS1 is the departure azimuth angle of the UAV transmitter to the intelligent reflecting surface RIS1; β T,RIS1 is the departure elevation angle of the UAV transmitter to the intelligent reflecting surface RIS1; α R,RIS1 is the arrival azimuth angle of the intelligent reflecting surface RIS1 to the mobile receiver;

[0144] β R,RIS1 is the arrival elevation angle of the intelligent reflecting surface RIS1 to the mobile receiver; η T is the angle in the elevation direction of the UAV motion, and γ T is the angle in the azimuth direction of the UAV motion;

[0145] η R is the angle of the mobile receiver motion direction;

[0146] η RIS2 is the energy correlation coefficient from the UAV transmitter to the mobile receiver through the intelligent reflecting surface RIS2;

[0147] α T,RIS2 is the departure azimuth angle of the UAV transmitter to the intelligent reflecting surface RIS2;

[0148] β T,RIS2is the departure elevation angle from the UAV transmitter to the intelligent reflecting surface RIS2;

[0149] α R,RIS2 is the arrival azimuth angle from the intelligent reflecting surface RIS2 to the receiving end of the mobile receiver; β R,RIS2 is the arrival elevation angle from the intelligent reflecting surface RIS2 to the receiving end of the mobile receiver;

[0150] η RIS1,RIS2 is the energy correlation coefficient from the UAV transmitter through the intelligent reflecting surfaces RIS1 and RIS2 to the receiving end of the mobile receiver;

[0151] φ0 is random and represents the NLOS initial phase;

[0152] α T,c1 is the departure azimuth angle from the UAV transmitter to the scattering cluster Cluster1;

[0153] β T,c1 is the departure elevation angle from the UAV transmitter to the scattering cluster Cluster1;

[0154] α R,c1 is the arrival azimuth angle from the scattering cluster Cluster1 to the receiving end of the mobile receiver; β R,c1 is the arrival elevation angle from the scattering cluster Cluster1 to the receiving end of the mobile receiver; α T,c2 is the departure azimuth angle from the intelligent reflecting surface RIS1 to the scattering cluster Cluster2; β T,c2 is the departure elevation angle from the intelligent reflecting surface RIS1 to the scattering cluster Cluster2; α R,c2 is the arrival azimuth angle from the scattering cluster Cluster2 to the intelligent reflecting surface RIS2; β R,c2 is the arrival elevation angle from the scattering cluster Cluster2 to the intelligent reflecting surface RIS2.

[0155] Compared with the prior art, the beneficial effects achieved by the present invention:

[0156] The present invention obtains the complex channel gain of the multipath components according to the distance relationship among the UAV, the dual intelligent reflecting surfaces, and the mobile receiver; obtains the space-time correlation function based on the dual intelligent reflecting surface assistance according to the complex channel gain of the multipath components, analyzes according to the correlation function, and obtains the influence of the number of reflecting units, the deflection angle of the dual intelligent reflecting surfaces, and the height of the UAV on the UAV channel, which is beneficial to studying the influence of the dual intelligent reflecting surfaces on the statistical characteristics of the UAV channel, and solves the problems that there are few research results on the channel modeling of the dual intelligent reflecting surfaces cooperating to assist UAV communication and it is very difficult to evaluate the performance of the communication system. Description of the Drawings

[0157] Figure 1It is a flowchart of a three-dimensional geometric channel modeling method for unmanned aerial vehicles provided by an embodiment of the present invention;

[0158] Figure 2 It is a schematic diagram of three-dimensional geometric channel modeling based on a dual-intelligent reflecting surface-assisted unmanned aerial vehicle in a three-dimensional geometric channel modeling method provided by an embodiment of the present invention (in the figure, MT is the unmanned aerial vehicle transmitting end; MR is the mobile receiver receiving end);

[0159] Figure 3 For the intelligent reflecting surface RIS2 with different deflection angles θ RIS2 The schematic diagram of spatial correlation below;

[0160] Figure 4 The schematic diagram of spatial correlation for different propagation links;

[0161] Figure 5 The schematic diagram of spatial correlation when the unmanned aerial vehicle is at different heights. Specific embodiments

[0162] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and cannot be used to limit the protection scope of the present invention.

[0163] Embodiment

[0164] As Figure 1 shown, a three-dimensional geometric channel modeling method for unmanned aerial vehicles includes:

[0165] Construct a three-dimensional geometric model based on a dual-intelligent reflecting surface-assisted unmanned aerial vehicle;

[0166] As Figure 2 shown, the three-dimensional geometric model based on a dual-intelligent reflecting surface-assisted unmanned aerial vehicle includes an unmanned aerial vehicle in the air, a mobile receiver on the ground, an intelligent reflecting surface RIS1 deployed near the unmanned aerial vehicle and the mobile receiver, an intelligent reflecting surface RIS2, a scattering cluster Cluster1 located between the unmanned aerial vehicle and the mobile receiver, and a scattering cluster Cluster2 located between the intelligent reflecting surface RIS1 and the intelligent reflecting surface RIS2;

[0167] According to the three-dimensional geometric model of the unmanned aerial vehicle, obtain the distance relationship between the unmanned aerial vehicle, the dual-intelligent reflecting surface and the mobile receiver. Specifically:

[0168] The coordinates of the centers of the intelligent reflecting surface RIS1, the intelligent reflecting surface RIS2, the scattering cluster Cluster1 and the scattering cluster Cluster2 are respectively (x RIS1 , y RIS1 , z RIS1 ), (x RIS2 , y RIS2 , zRIS2 ), (x c1 , y c1 , z c1 ) and (x c2 , y c2 , z c2 );

[0169] The distance from the p-th antenna of the UAV transmitter to the (m x1 , m z1 )-th unit in the intelligent reflecting surface RIS1 is The calculation formula is as follows:

[0170]

[0171] The distance from the q-th antenna of the mobile receiver to the (m x1 , m z1 )-th unit in the intelligent reflecting surface RIS1 is The calculation formula is as follows:

[0172]

[0173] The distance from the p-th antenna of the UAV transmitter to the (m x2 , m z2 )-th unit in the intelligent reflecting surface RIS2 is The calculation formula is as follows:

[0174]

[0175]

[0176] The distance from the q-th antenna of the mobile receiver to the (m x2 , m z2 )-th unit in the intelligent reflecting surface RIS2 is The calculation formula is as follows:

[0177]

[0178] The distance from the (m x1 , m z1 )-th unit in the intelligent reflecting surface RIS1 to the (m x2 , m z2 )-th unit in the intelligent reflecting surface RIS2 The calculation formula is as follows:

[0179]

[0180] The distance from the p-th antenna of the UAV transmitter to the scattering cluster Cluster1 The calculation formula is as follows:

[0181]

[0182] The distance from the q-th antenna at the receiving end of the mobile receiver to the scattering cluster Cluster1 The calculation formula is as follows:

[0183]

[0184] The distance from the scattering cluster Cluster2 to the (m x1 , m z1 )-th unit in the intelligent reflecting surface RIS1 is The calculation formula is as follows:

[0185]

[0186] The distance from the scattering cluster Cluster2 to the (m x2 , m z2 )-th unit in the intelligent reflecting surface RIS2 is The calculation formula is as follows:

[0187]

[0188] Where:

[0189] P represents the number of antennas at the transmitting end of the UAV, and Q represents the number of antennas at the receiving end of the mobile receiver;

[0190] p represents the p-th antenna at the transmitting end of the UAV, and q represents the q-th antenna at the receiving end of the mobile receiver;

[0191] d0 represents the lateral distance between the center of the antenna at the transmitting end of the UAV and the center of the antenna at the receiving end of the mobile receiver;

[0192] θ RIs1 is the rotation angle of the intelligent reflecting surface RIS1 relative to the x-axis;

[0193] δ T is the distance between two adjacent antennas at the transmitting end of the UAV;

[0194] ψ T is the direction of the transmitting antenna array at the transmitting end of the UAV;

[0195] d x1 and d z1 are the horizontal and vertical sizes of each unit in the intelligent reflecting surface RIS1

[0196] M x1 is the total number of units arranged horizontally in the intelligent reflecting surface RIS1, and M x2 is the total number of units arranged horizontally in the intelligent reflecting surface RIS2;

[0197] M z1 is the total number of units arranged vertically in the intelligent reflecting surface RIS1, M z2 is the total number of units arranged vertically in the intelligent reflecting surface RIS2;

[0198] h0 is the height at which the UAV flies;

[0199] θ RIS2 is the rotation angle of the intelligent reflecting surface RIS2 relative to the x-axis;

[0200] δ R is the distance between two adjacent antennas at the receiving end of the mobile receiver;

[0201] ψ R is the direction of the antenna array at the receiving end of the mobile receiver;

[0202] d x2 and d z2 are the horizontal and vertical sizes of each unit in the intelligent reflecting surface RIS2;

[0203] m x1p is the distance from the p-th antenna at the transmitting end of the UAV to the m x1 -th unit in the intelligent reflecting surface RIS1;

[0204] m z1p is the distance from the p-th antenna at the transmitting end of the UAV to the m z1 -th unit in the intelligent reflecting surface RIS1;

[0205] m x1q is the distance from the q-th antenna at the receiving end of the mobile receiver to the m x1 -th unit in the intelligent reflecting surface RISl; m z1q is the distance from the q-th antenna at the receiving end of the mobile receiver to the m z1 -th unit in the intelligent reflecting surface RIS1; m x1c2 is the distance from the m x1 -th unit in the intelligent reflecting surface RIS1 to the scattering cluster Cluster2; m z1c2 is the distance from the m z1 -th unit in the intelligent reflecting surface RIS1 to the scattering cluster Cluster2; m x2p is the distance from the p-th antenna at the transmitting end of the UAV to the m x2 -th unit in the intelligent reflecting surface RIS2; m z2p is the distance from the p-th antenna at the transmitting end of the UAV to the m z2 -th unit in the intelligent reflecting surface RIS2; m x2q is the distance from the q-th antenna at the receiving end of the mobile receiver to the m x2Distance of the m-th unit; m z2q is the distance from the q-th antenna at the receiving end of the mobile receiver to the m-th z2 unit in RIS2; m x2c2 is the distance from the m-th unit in RIS2 to the scattering cluster Cluster2; m x2 is the distance from the m-th unit in RIS2 to the scattering cluster Cluster2; m z2c2 is the distance from the m-th unit in RIS2 to the scattering cluster Cluster2; m z2 is the distance from the m-th unit in RIS2 to the scattering cluster Cluster2.

[0206] According to the distance relationship among the UAV, the double intelligent reflecting surface and the mobile receiver, obtain the complex channel gain of the multipath component. Specifically:

[0207] The channel gain of the multipath component is:

[0208]

[0209] where h pq (t) represents the complex channel gain of the multipath component between the p-th antenna at the transmitting end of the UAV and the q-th antenna at the receiving end of the mobile receiver, and t represents the time variable;

[0210] represents the complex channel gain of the LoS component between the p-th antenna at the transmitting end of the UAV and the q-th antenna at the receiving end of the mobile receiver passing through RIS1;

[0211] represents the complex channel gain of the LoS component between the p-th antenna at the transmitting end of the UAV and the q-th antenna at the receiving end of the mobile receiver passing through RIS2;

[0212] represents the complex channel gain of the LoS component between the p-th antenna at the transmitting end of the UAV and the q-th antenna at the receiving end of the mobile receiver passing through RIS1 and RIS2;

[0213] represents the complex channel gain of the NLoS component between the p-th antenna at the transmitting end of the UAV and the q-th antenna at the receiving end of the mobile receiver passing through the scattering cluster Cluster1;

[0214] represents the complex channel gain of the LoS component between the p-th antenna at the transmitting end of the UAV and the q-th antenna at the receiving end of the mobile receiver passing through RIS1, the scattering cluster Cluster2, and RIS2.

[0215] The complex channel gain of the multipath component between the p-th antenna at the transmitting end of the UAV and the q-th antenna at the receiving end of the mobile receiver has the following calculation formula:

[0216]

[0217] The complex channel gain of the LoS component between the p-th antenna of the UAV transmitter and the q-th antenna of the mobile receiver through the intelligent reflecting surface RIS1 The calculation formula is as follows:

[0218]

[0219]

[0220] The complex channel gain of the LoS component between the p-th antenna of the UAV transmitter and the q-th antenna of the mobile receiver through the intelligent reflecting surface RIS2 The calculation formula is as follows:

[0221]

[0222] The complex channel gain of the NLoS component between the p-th antenna of the UAV transmitter and the q-th antenna of the mobile receiver through the scattering cluster Cluster1 The calculation formula is as follows:

[0223]

[0224] The complex channel gain of the LoS component between the p-th antenna of the UAV transmitter and the q-th antenna of the mobile receiver through the intelligent reflecting surface RIS1, the scattering cluster Cluster2, and the intelligent reflecting surface RIS2 The calculation formula is as follows:

[0225]

[0226] Where:

[0227] is the distance from the p-th antenna of the UAV transmitter to the (m x1 , m z1 )-th unit in the intelligent reflecting surface RIS1;

[0228] is the distance from the q-th antenna of the mobile receiver to the (m x1 , m z1 )-th unit in the intelligent reflecting surface RIS1;

[0229] is the distance from the p-th antenna of the UAV transmitter to the (m x2 , m z2 )-th unit in the intelligent reflecting surface RIS2;

[0230] is the distance from the q-th antenna at the receiving end of the mobile receiver to the (m x2 , m z2 )-th unit in the intelligent reflecting surface RIS2;

[0231] is the distance from the (m x1 , m z1 )-th unit in the intelligent reflecting surface RIS1 to the (m x2 , m z2 )-th unit in the intelligent reflecting surface RIS2;

[0232] is the distance from the p-th antenna at the transmitting end of the UAV to the scattering cluster Cluster1;

[0233] is the distance from the q-th antenna at the receiving end of the mobile receiver to the scattering cluster Cluster1;

[0234] is the distance from the scattering cluster Cluster2 to the (m x1 , m z1 )-th unit in the intelligent reflecting surface RIS1;

[0235] is the distance from the scattering cluster Cluster2 to the (m x2 , m z2 )-th unit in the intelligent reflecting surface RIS2;

[0236] fc is the carrier frequency, K is the Rice factor, t is the motion time, c is the speed of light, and λ is the carrier wavelength;

[0237] η RIS1 represents the energy correlation coefficient from the transmitting end of the UAV passing through the intelligent reflecting surface RIS1 to the receiving end of the mobile receiver;

[0238] v T is the moving speed of the UAV, and v R is the moving speed of the mobile receiver;

[0239] α T，RIS1 is the departure azimuth angle of the transmitting end of the UAV reaching the intelligent reflecting surface RIS1; β T，RIs1 is the departure elevation angle of the transmitting end of the UAV reaching the intelligent reflecting surface RIS1; α R，RIS1 is the arrival azimuth angle of the intelligent reflecting surface RIS1 reaching the receiving end of the mobile receiver;

[0240] β T，RIS1 is the arrival elevation angle of the intelligent reflecting surface RIS1 reaching the receiving end of the mobile receiver; η T is the angle in the elevation direction of the UAV's motion, γT is the angle in the azimuth direction of the UAV's movement;

[0241] η R is the angle of the moving receiver's movement direction; η RIS2 is the energy correlation coefficient from the UAV's transmitting end, through the intelligent reflecting surface RIS2, to the mobile receiver's receiving end;

[0242] α T，RIS2 is the departure azimuth angle from the UAV's transmitting end to the intelligent reflecting surface RIS2;

[0243] β T，RIS2 is the departure elevation angle from the UAV's transmitting end to the intelligent reflecting surface RIS2; α R，RIS2 is the arrival azimuth angle from the intelligent reflecting surface RIS2 to the mobile receiver's receiving end, β R，RIS2 is the arrival elevation angle from the intelligent reflecting surface RIS2 to the mobile receiver's receiving end, η RIS1，RIS2 is the energy correlation coefficient from the UAV's transmitting end, through the intelligent reflecting surface RIS1 and the intelligent reflecting surface RIS2, to the mobile receiver's receiving end;

[0244] φ0 is random and represents the NLOS initial phase;

[0245] α T，c1 is the departure azimuth angle from the UAV's transmitting end to the scattering cluster Cluster1; β T，c1 is the departure elevation angle from the UAV's transmitting end to the scattering cluster Cluster1; α R，c1 is the arrival azimuth angle from the scattering cluster Cluster1 to the mobile receiver's receiving end; β R，c1 is the arrival elevation angle from the scattering cluster Cluster1 to the mobile receiver's receiving end; α T，c2 is the departure azimuth angle from the intelligent reflecting surface RIS1 to the scattering cluster Cluster2; β T，c2 is the departure elevation angle from the intelligent reflecting surface RIS1 to the scattering cluster Cluster2; α R，c2 is the arrival azimuth angle from the scattering cluster Cluster2 to the intelligent reflecting surface RIS2; β R，c2 is the arrival elevation angle from the scattering cluster Cluster2 to the intelligent reflecting surface RIS2.

[0246] According to the complex channel gain of the multipath components, obtain the spatio-temporal correlation function of the dual-intelligent-reflecting-surface-assisted UAV. Specifically:

[0247] The spatio-temporal correlation function of the dual-intelligent-reflecting-surface-assisted UAV is:

[0248]

[0249]

[0250] where: ()* represents the complex conjugate operation; E[·] represents the expectation operation; Δt represents the time difference;

[0251] represents the spatio-temporal correlation of the propagation link through the reconfigurable intelligent surface (RIS1);

[0252] represents the spatio-temporal correlation of the propagation link through the reconfigurable intelligent surface (RIS2);

[0253] represents the spatio-temporal correlation of the propagation link through the reconfigurable intelligent surfaces (RIS1 and RIS2);

[0254] represents the spatio-temporal correlation of the propagation link through the scatterer cluster (Cluster1);

[0255] represents the spatio-temporal correlation of the propagation link through the reconfigurable intelligent surfaces (RIS1, RIS2) and the scatterer cluster (Cluster2).

[0256] The spatio-temporal correlation of the propagation link through the reconfigurable intelligent surface (RIS1) The formula is:

[0257]

[0258] The spatio-temporal correlation of the propagation link through the reconfigurable intelligent surface (RIS2) The formula is:

[0259]

[0260] The spatio-temporal correlation of the propagation link through the reconfigurable intelligent surfaces (RIS1 and RIS2) The formula is:

[0261]

[0262]

[0263] The spatio-temporal correlation of the propagation link through the scatterer cluster (Cluster1) The formula is:

[0264]

[0265] The spatio-temporal correlation of the propagation link through the reconfigurable intelligent surfaces (RIS1, RIS2) and the scatterer cluster (Cluster2) The formula is:

[0266]

[0267] Among them, M x1 is the total number of elements arranged horizontally in the reconfigurable intelligent surface (RIS) 1, and M x2 is the total number of elements arranged horizontally in the reconfigurable intelligent surface (RIS) 2;

[0268] M z1 is the total number of elements arranged vertically in the reconfigurable intelligent surface (RIS) 1, and M z2 is the total number of elements arranged vertically in the reconfigurable intelligent surface (RIS) 2;

[0269] p' represents the p'th antenna, and q' represents the q'th antenna;

[0270] represents the distance from the p'th antenna to the (m x1 , m z1 )-th element in the reconfigurable intelligent surface (RIS) 1; represents the distance from the q'th antenna to the (m x1 , m z1 )-th element in the reconfigurable intelligent surface (RIS) 1; represents the distance from the p'th antenna to the (m x2 , m z2 )-th element in the reconfigurable intelligent surface (RIS) 2; represents the distance from the q'th antenna to the (m x2 , m z2 )-th element in the reconfigurable intelligent surface (RIS) 2; d p'c1 represents the distance from the p'th antenna to the scattering cluster Cluster1; d q'c1 represents the distance from the q'th antenna to the scattering cluster Cluster1;

[0271] fc is the carrier frequency, K is the Rice factor, t is the motion time, c is the speed of light, and λ is the carrier wavelength;

[0272] η RIS1 represents the energy correlation coefficient from the UAV transmitter to the mobile receiver through the reconfigurable intelligent surface (RIS) 1;

[0273] v T is the moving speed of the UAV, and v R is the moving speed of the mobile receiver;

[0274] α T,RIS1 is the departure azimuth angle of the UAV transmitter to the reconfigurable intelligent surface (RIS) 1; β T,RIS1 is the departure elevation angle of the UAV transmitter to the reconfigurable intelligent surface (RIS) 1; α T,RIS2 is the departure azimuth angle of the UAV to the reconfigurable intelligent surface (RIS) 2; β T,RIS2is the departure elevation angle from the UAV to the intelligent reflecting surface RIS2;

[0275] α R,RIS1 is the azimuth angle of arrival from the intelligent reflecting surface RIS1 to the receiving end of the mobile receiver; β R,RIS1 is the elevation angle of arrival from the intelligent reflecting surface RIS1 to the receiving end of the mobile receiver; α R,RIS2 is the azimuth angle of arrival from the intelligent reflecting surface RIS2 to the receiving end of the mobile receiver; β R,RIS2 is the elevation angle of arrival from the intelligent reflecting surface RIS2 to the receiving end of the mobile receiver;

[0276] η T is the angle in the elevation direction of the UAV's movement, γ T is the angle in the azimuth direction of the UAV's movement; η R is the angle of the mobile receiver's movement direction; η RIS2 is the energy correlation coefficient from the UAV transmitter through the intelligent reflecting surface RIS2 to the receiving end of the mobile receiver; η RIS1,RIS2 is the energy correlation coefficient from the UAV through the intelligent reflecting surfaces RIS1 and RIS2 to the receiving end of the mobile receiver;

[0277] φ0 is random and represents the initial phase of NLOS;

[0278] α T,c1 is the azimuth angle of departure from the UAV transmitter to the scattering cluster Cluster1; β T,c1 is the elevation angle of departure from the UAV transmitter to the scattering cluster Cluster1; α R,c1 is the azimuth angle of arrival from the scattering cluster Cluster1 to the receiving end of the mobile receiver; β R,c1 is the elevation angle of arrival from the scattering cluster Cluster1 to the receiving end of the mobile receiver;

[0279] α T,c2 is the azimuth angle of departure from the intelligent reflecting surface RIS1 to the scattering cluster Cluster2; β T,c2 is the elevation angle of departure from the intelligent reflecting surface RIS1 to the scattering cluster Cluster2; α R,c2 is the azimuth angle of arrival from the scattering cluster Cluster2 to the intelligent reflecting surface RIS2; β R,c2 is the elevation angle of arrival from the scattering cluster Cluster2 to the intelligent reflecting surface RIS2.

[0280] Obtain the influence of the dual intelligent reflecting surface on the three-dimensional geometric channel characteristics of the UAV through correlation analysis. Specifically: as Figure 3 shown, when θ RIS2When it drops from π / 6 to -π / 6, the spatial correlation gradually increases, proving that the deflection angle of the intelligent reflecting surface affects the channel correlation, indicating that for intelligent reflecting surfaces with different deflection angles, the spatial correlation will be different; as Figure 4 shown, when the transmitter passes through RIS1 to reach the receiver, M x1 and M z1 rise from 20 to 200, the spatial correlation drops rapidly; similarly, when the transmitter passes through the intelligent reflecting surface RIS2 to reach the receiver, M x2 and M z2 rise from 20 to 200, the spatial correlation also drops rapidly; this indicates that the spatial correlations of different propagation links are different, and the spatial correlations of intelligent reflecting surfaces with different sizes are also different; as Figure 5 shown, the fluctuation of the spatial correlation decreases with the increase of the antenna spacing; in addition, different UAV heights h0 will result in different spatial correlations, indicating the spatial non-stationarity of the proposed channel model; at the same time, simulation can show that the channel model proposed by the present invention can change the spatial correlation and improve the propagation quality.

[0281] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and deformations can still be made, and these improvements and deformations should also be regarded as the protection scope of the present invention.

Claims

1. A three-dimensional geometric channel modeling method for unmanned aerial vehicles, characterized in that, Including: Based on the three-dimensional geometric model of the unmanned aerial vehicle (UAV), obtain the distance relationship among the UAV, the dual intelligent reflecting surface, and the mobile receiver; Based on the distance relationship among the UAV, the dual intelligent reflecting surface, and the mobile receiver, obtain the complex channel gain of the multipath component, and the complex channel gain of the multipath component is: ； Among them, represents the complex channel gain of the multipath component between the p-th antenna of the UAV transmitting end and the q-th antenna of the mobile receiver receiving end, and t represents the time variable; Denote the complex channel gain of the LoS component between the \(p\)-th antenna of the UAV transmitter and the \(q\)-th antenna of the mobile receiver through the intelligent reflecting surface RIS1. Denote the complex channel gain of the LoS component between the p-th antenna of the UAV transmitter, through the intelligent reflecting surface RIS2, and the q-th antenna of the mobile receiver Denote the complex channel gain of the LoS component between the \(p\)-th antenna of the UAV transmitter and the \(q\)-th antenna of the mobile receiver via the IRS1 and IRS2. Denote the complex channel gain of the NLoS component between the p-th antenna of the UAV transmitter and the q-th antenna of the mobile receiver through the scattering cluster Cluster1. Denote the complex channel gain of the LoS component between the \(p\)-th antenna of the UAV transmitter, passing through the intelligent reflecting surface RIS1, the scattering cluster Cluster2, and the intelligent reflecting surface RIS2, to the \(q\)-th antenna of the mobile receiver. Before obtaining the distance relationship among the UAV, the dual intelligent reflecting surface, and the mobile receiver, construct a three-dimensional geometric model of the UAV assisted by the dual intelligent reflecting surface; The three-dimensional geometric model of the UAV assisted by the dual intelligent reflecting surface includes the UAV in the air, the mobile receiver on the ground, the intelligent reflecting surface RIS1 deployed near the UAV and the mobile receiver, the intelligent reflecting surface RIS2, the scattering cluster Cluster1 between the UAV and the mobile receiver, and the scattering cluster Cluster2 between the intelligent reflecting surface RIS1 and the intelligent reflecting surface RIS2; Based on the complex channel gain of the multipath component, obtain the space-time correlation function of the UAV assisted by the dual intelligent reflecting surface, and through correlation analysis, obtain the influence of the dual intelligent reflecting surface on the three-dimensional geometric channel characteristics of the UAV; The space-time correlation function of the UAV assisted by the dual intelligent reflecting surface is: ； ； Where: ()* represents the complex conjugate operation; E[·] represents the expectation operation; ∆t represents the time difference; Denote the spatio-temporal correlation of the propagation link through the intelligent reflecting surface RIS1; Denote the spatio-temporal correlation of the propagation link through the intelligent reflecting surface RIS2; Indicates the spatio-temporal correlation of the propagation links passing through the intelligent reflecting surface RIS1 and the intelligent reflecting surface RIS2; Represents the spatio-temporal correlation of the propagation link passing through the scattering cluster Cluster1; Indicates the spatio-temporal correlation of the propagation link passing through the intelligent reflecting surface RIS1, intelligent reflecting surface RIS2, and scattering cluster Cluster2.

2. The method for three-dimensional geometric channel modeling of an unmanned aerial vehicle according to claim 1, wherein The method for obtaining the distance relationship among the UAV, the dual intelligent reflecting surface, and the mobile receiver based on the three-dimensional geometric model of the UAV includes: The coordinates of the centers of the intelligent reflecting surface RIS1, intelligent reflecting surface RIS2, scattering cluster Cluster1, and scattering cluster Cluster2 are respectively ( , , ), ( , , ), ( , , ), and ( , , ); The distance from the p-th antenna of the UAV transmitter to the th unit in the intelligent reflecting surface RIS1 is , and the calculation formula is as follows: ； The distance from the q-th antenna at the receiving end of the mobile receiver to the -th unit in the intelligent reflecting surface RIS1 is , and the calculation formula is as follows: ； The distance from the p-th antenna of the UAV transmitter to the -th unit in the intelligent reflecting surface RIS2 is , and the calculation formula is as follows: ； The distance from the q-th antenna at the receiving end of the mobile receiver to the -th unit in the intelligent reflecting surface RIS2 is , and the calculation formula is as follows: ； The distance from the th unit in the intelligent reflecting surface RIS1 to the th unit in the intelligent reflecting surface RIS2 is calculated as follows: ； The distance from the p-th antenna of the UAV transmitter to the scattering cluster Cluster1 , and the calculation formula is as follows: ； The distance from the q-th antenna at the receiving end of the mobile receiver to the scattering cluster Cluster1 , and the calculation formula is as follows: ； The distance from Scattering Cluster 2 to the th cell in Intelligent Reflecting Surface RIS1 is , and the calculation formula is as follows: ； The distance from Scattering Cluster 2 to the th unit in the Reconfigurable Intelligent Surface (RIS) 2 is , and the calculation formula is as follows: ； Where: P represents the number of antennas at the UAV transmitting end, and Q represents the number of antennas at the mobile receiver receiving end; p represents the p-th antenna at the UAV transmitting end, and q represents the q-th antenna at the mobile receiver receiving end; represents the lateral distance between the center of the transmitting antenna of the UAV and the center of the receiving antenna of the mobile receiver; is the rotation angle of the intelligent reflecting surface RIS1 relative to the x-axis; is the distance between two adjacent antennas at the UAV transmitting end; is the direction of the transmitting antenna array of the UAV transmitting end; and are the sizes of each unit in the intelligent reflecting surface RIS1 in the horizontal and vertical directions is the total number of units arranged horizontally for the intelligent reflecting surface RIS1, is the total number of units arranged horizontally for the intelligent reflecting surface RIS2; is the total number of units arranged vertically for the intelligent reflecting surface RIS1, is the total number of units arranged vertically for the intelligent reflecting surface RIS2; is the altitude at which the drone flies; is the rotation angle of the intelligent reflecting surface RIS2 with respect to the x-axis; is the distance between two adjacent antennas at the receiving end of the mobile receiver; is the direction of the antenna array at the receiving end of the mobile receiver; and are the horizontal and vertical directions of each unit in the intelligent reflecting surface RIS2 The magnitude of; is the distance from the p-th antenna of the UAV transmitter to the n-th unit in the intelligent reflecting surface RIS1; is the distance from the p-th antenna of the UAV transmitter to the n-th unit of the intelligent reflecting surface RIS1; is the distance from the q-th antenna at the receiving end of the mobile receiver to the n-th unit in the intelligent reflecting surface RIS1; is the distance from the q-th antenna at the receiving end of the mobile receiver to the n-th unit in the intelligent reflecting surface RIS1; is the distance from the th unit in the intelligent reflecting surface RIS1 to the scattering cluster Cluster2; is the distance from the th unit in the intelligent reflecting surface RIS1 to the scattering cluster Cluster2; is the distance from the p-th antenna of the UAV transmitter to the n-th unit in the intelligent reflecting surface RIS2; is the distance from the p-th antenna of the UAV transmitter to the n-th unit of the intelligent reflecting surface RIS2; is the distance from the q-th antenna at the receiving end of the mobile receiver to the n-th unit in the intelligent reflecting surface RIS2; is the distance from the q-th antenna at the receiving end of the mobile receiver to the -th unit in the intelligent reflecting surface RIS2; is the distance from the nth unit in the intelligent reflecting surface RIS2 to the scattering cluster Cluster2; is the distance from the th unit in the intelligent reflecting surface RIS2 to the scattering cluster Cluster2.

3. The method for three-dimensional geometric channel modeling of an unmanned aerial vehicle according to claim 1, wherein The complex channel gain of the multipath component between the p-th antenna of the UAV transmitter and the q-th antenna of the mobile receiver is calculated by the formula: ； The complex channel gain of the LoS component between the p-th antenna of the UAV transmitter and the q-th antenna of the mobile receiver through the intelligent reflecting surface RIS1 is calculated as follows: ； The complex channel gain of the LoS component between the p-th antenna of the UAV transmitter and the q-th antenna of the mobile receiver through the intelligent reflecting surface RIS2 is calculated as follows: ； The complex channel gain of the NLoS component between the p-th antenna of the UAV transmitter and the q-th antenna of the mobile receiver via the scattering cluster Cluster1 is calculated as follows: ； The complex channel gain of the LoS component between the p-th antenna of the UAV transmitter, through the intelligent reflecting surface RIS1, the scattering cluster Cluster2, the intelligent reflecting surface RIS2, and the q-th antenna of the mobile receiver is calculated as follows: ； Wherein, is the distance from the p-th antenna of the UAV transmitter to the -th unit in the intelligent reflecting surface RIS1; The distance from the q-th antenna at the receiving end of the mobile receiver to the n-th unit in the intelligent reflecting surface RIS1 is is the distance from the p-th antenna of the UAV transmitter to the n-th unit in the intelligent reflecting surface RIS2; is the distance from the q-th antenna at the receiving end of the mobile receiver to the -th unit in the intelligent reflecting surface RIS2; is the distance from the -th unit in the intelligent reflecting surface RIS1 to the -th unit in the intelligent reflecting surface RIS2; is the distance from the p-th antenna of the UAV transmitter to the scattering cluster Cluster1; The distance from the q-th antenna at the receiving end of the mobile receiver to the scattering cluster Cluster1; is the distance from the scattering cluster Cluster2 to the th unit in the intelligent reflecting surface RIS1; is the distance from the scattering cluster Cluster2 to the th unit in the intelligent reflecting surface RIS2; fc is the carrier frequency, K is the Rice factor, t is the motion time, c is the speed of light, λ is the carrier wavelength; Denote the energy correlation coefficient from the UAV transmitter through the intelligent reflecting surface RIS1 to the mobile receiver is the moving speed of the drone, is the moving speed of the mobile receiver; is the departure azimuth angle of the UAV transmitter to reach the intelligent reflecting surface RIS1; is the departure elevation angle of the UAV transmitter to reach the intelligent reflecting surface RIS1; is the arrival azimuth angle of the intelligent reflecting surface RIS1 to reach the receiving end of the mobile receiver; is the elevation angle of arrival of the intelligent reflecting surface RIS1 at the receiving end of the mobile receiver; is the angle in the elevation direction of the UAV's movement, is the angle in the azimuth direction of the UAV's movement; is the angle of the moving direction of the mobile receiver; is the energy correlation coefficient from the UAV transmitter, through the intelligent reflecting surface RIS2, to the mobile receiver is the departure azimuth angle from the UAV transmitter to the intelligent reflecting surface RIS2; is the departure elevation angle from the UAV transmitter to the intelligent reflecting surface RIS2; is the azimuth angle of arrival from the intelligent reflecting surface RIS2 to the receiving end of the mobile receiver, is the elevation angle of arrival from the intelligent reflecting surface RIS2 to the receiving end of the mobile receiver, is the energy correlation coefficient from the transmitting end of the unmanned aerial vehicle, through the intelligent reflecting surface RIS1 and the intelligent reflecting surface RIS2, to the receiving end of the mobile receiver; is random and represents the NLOS initial phase; is the departure azimuth angle of the UAV transmitter end arriving at the scattering cluster Cluster1; is the departure elevation angle of the UAV transmitter when it reaches the scattering cluster Cluster1; is the azimuth angle of arrival of scatterer cluster Cluster1 at the receiving end of the mobile receiver; is the elevation angle of arrival of scatterer cluster Cluster1 at the receiving end of the mobile receiver; is the departure azimuth angle of intelligent reflecting surface RIS1 to scatterer cluster Cluster2; is the departure elevation angle of intelligent reflecting surface RIS1 to scatterer cluster Cluster2; is the azimuth angle of arrival of scatterer cluster Cluster2 at intelligent reflecting surface RIS2; is the elevation angle of arrival of scatterer cluster Cluster2 at intelligent reflecting surface RIS2.

4. The method for three-dimensional geometric channel modeling of an unmanned aerial vehicle according to claim 1, characterized in that The spatio-temporal correlation of the propagation link passing through the intelligent reflecting surface RIS1 The formula is as follows: ； The spatio-temporal correlation of the propagation link through the intelligent reflecting surface RIS2 The formula is as follows: ； The spatio-temporal correlation of the propagation link passing through the intelligent reflecting surface RIS1 and the intelligent reflecting surface RIS2 The formula is as follows: ； The spatio-temporal correlation of the propagation link passing through the scattering cluster Cluster1 The formula is as follows: ； The spatio-temporal correlation of the propagation link passing through the intelligent reflecting surface RIS1, intelligent reflecting surface RIS2, and scattering cluster Cluster2 The formula is as follows: ； Among them, is the total number of units arranged horizontally in the intelligent reflecting surface RIS1, is the total number of units arranged horizontally in the intelligent reflecting surface RIS2; is the total number of units arranged vertically in the intelligent reflecting surface RIS1, is the total number of units arranged vertically in the intelligent reflecting surface RIS2; p’ represents the p’-th antenna, and q’ represents the q’-th antenna; Denote the distance from the p'-th antenna to the n-th unit in the intelligent reflecting surface RIS1; Denote the distance from the q'-th antenna to the th unit in the intelligent reflecting surface RIS1; Denote the distance from the p'-th antenna to the th unit in the intelligent reflecting surface RIS2; represents the distance from the q'-th antenna to the i-th unit in the intelligent reflecting surface RIS2; represents the distance from the p'-th antenna to the scattering cluster Cluster1; represents the distance from the q'-th antenna to the scattering cluster Cluster1; fc is the carrier frequency, K is the Rice factor, t is the motion time, c is the speed of light, λ is the carrier wavelength; Indicates the energy correlation coefficient from the UAV transmitter through the intelligent reflecting surface RIS1 to the mobile receiver is the moving speed of the drone, is the moving speed of the mobile receiver; is the departure azimuth angle of the UAV transmitter to the intelligent reflecting surface RIS1; is the departure elevation angle of the UAV transmitter to the intelligent reflecting surface RIS1; is the arrival azimuth angle of the intelligent reflecting surface RIS1 to the receiving end of the mobile receiver; is the elevation angle of arrival of the intelligent reflecting surface RIS1 at the receiving end of the mobile receiver; is the angle in the elevation direction of the UAV's movement, is the angle in the azimuth direction of the UAV's movement; is the angle of the moving direction of the mobile receiver; is the energy correlation coefficient from the UAV transmitter through the intelligent reflecting surface RIS2 to the mobile receiver at the receiving end; is the departure azimuth angle from the UAV transmitter to the intelligent reflecting surface RIS2; is the departure elevation angle from the UAV transmitter to the intelligent reflecting surface RIS2; is the azimuth angle of arrival from the intelligent reflecting surface RIS2 to the receiving end of the mobile receiver; is the elevation angle of arrival from the intelligent reflecting surface RIS2 to the receiving end of the mobile receiver; is the energy correlation coefficient from the UAV transmitter to the mobile receiver through the intelligent reflecting surface RIS1 and the intelligent reflecting surface RIS2; is random and represents the NLOS initial phase; is the departure azimuth angle when the UAV transmitter reaches the scattering cluster Cluster1; is the departure elevation angle of the UAV transmitter when it reaches the scattering cluster Cluster1; is the azimuth angle of arrival of scatterer cluster Cluster1 at the receiving end of the mobile receiver; is the elevation angle of arrival of scatterer cluster Cluster1 at the receiving end of the mobile receiver; is the departure azimuth angle of intelligent reflecting surface RIS1 to scatterer cluster Cluster2; is the departure elevation angle of intelligent reflecting surface RIS1 to scatterer cluster Cluster2; is the azimuth angle of arrival of scatterer cluster Cluster2 at intelligent reflecting surface RIS2; is the elevation angle of arrival of scatterer cluster Cluster2 at intelligent reflecting surface RIS2.

Images