A robust relay secure communication method for drones serving multiple users

Abstract

The present invention belongs to the field of wireless communication technology, and specifically relates to a robust relay secure communication method for drones to serve multiple users. The robust relay secure communication method for drones to serve multiple users uses drones as mobile relays to achieve communication in wireless channels that are severely faded. Its beneficial effects are: improving the robustness of the algorithm, maximizing energy efficiency and improving the energy efficiency of drone-enabled mobile relay security in consideration of the presence of multiple eavesdroppers, ensuring safe communication of aerial or ground drones in remote areas where the base station is located, and ensuring energy consumption management of drones, which is more in line with actual conditions. Not only that, drones as mobile relays have the advantages of low cost and high operability.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless communications, and in particular relates to a robust relay security communication method for unmanned aerial vehicles to serve multiple users. Background Art

[0002] Due to the high mobility, flexible configuration, and communication channels dominated by line-of-sight propagation of drones, their applications in the field of communications are becoming more and more extensive. Compared with traditional terrestrial communications such as ground base stations and access points, drone-enabled communications have flexible network structures and low configuration costs, and the attenuation of air-to-ground and ground-to-air line-of-sight propagation channels is smaller than that of ground communication channels. Therefore, to a certain extent, this will increase its transmission information capacity. However, due to the broadcast characteristics of wireless communications, drone-enabled communications are easily eavesdropped by external eavesdroppers, which will bring many security issues. Traditional security methods are mainly cryptographic methods, which are mainly based on computational complexity. However, due to the limited resources of drones, cryptographic methods are not applicable to drone communication systems. With the expansion of demand for drone networks, it is crucial to solve the physical layer security and build a secure drone communication system.

[0003] In wireless communications, a particularly promising use case is drone-enabled mobile relays. Due to the high mobility of drones, drone-enabled mobile relays can significantly improve the efficiency of data forwarding; on the other hand, considering that the direct channel between the sender and the receiver is blocked by obstacles and produces severe signal fading, the direct communication between the sender and the receiver will inevitably be affected, and drone-enabled mobile relays can assist in wireless communications in this case. Drones bring opportunities and challenges to wireless communications: on the one hand, drone-enabled mobile relays must ensure the secure transmission of confidential information; on the other hand, the limited resources of drones conflict with the computational complexity of secure transmission, so it is very important to design a reasonable algorithm to optimize the energy consumption and security rate of drones. Summary of the invention

[0004] In order to make up for the defects of the prior art, the present invention provides a robust relay secure communication method for unmanned aerial vehicle serving multiple users.

[0005] The present invention is achieved through the following technical solutions:

[0006] A robust relay secure communication method for unmanned aerial vehicle serving multiple users, specifically comprising the following steps:

[0007] Obtain the location and channel status information of users and base stations accessing the drone network;

[0008] Obtain the location and channel status information of each eavesdropper;

[0009] Calculate the path loss from the drone to the base station and to the receiving end based on the location of the base station and the user;

[0010] According to the location of the eavesdropper, calculate the path loss from the eavesdropper to the base station and to the drone;

[0011] The channel capacity of the eavesdropping channel is calculated based on the path loss from the drone to the eavesdropper;

[0012] Calculate the channel capacity of the main channel based on the path loss from the drone to the user;

[0013] The propulsion power of the drone is calculated based on the real-time speed and acceleration of the drone. Since the propulsion power is much greater than the power of transmitting information, the total energy consumption is the propulsion power.

[0014] The security capacity is calculated based on the difference between the main channel capacity and the eavesdropping channel capacity, and the security energy efficiency is calculated by the quotient of the security capacity and the energy consumption.

[0015] Furthermore, the channel status information is the channel properties of the communication links between the base station and the drone and between the drone and the user in the drone communication network, and the channel properties are mainly line-of-sight propagation loss; the channel status information of the eavesdropper is constructed, and the channel status information is the channel properties of the communication links from the eavesdropper to the base station and from the eavesdropper to the drone, and the channel properties are non-line-of-sight propagation loss and line-of-sight propagation loss respectively.

[0016] Furthermore, the channel state information from the base station to the drone is calculated using the following formula:

[0017]

[0018]

[0019] Furthermore, the channel state information from the drone to the user is calculated using the following formula:

[0020]

[0021]

[0022] Furthermore, the channel state information from the base station to the eavesdropper is calculated using the following formula:

[0023]

[0024]

[0025] Furthermore, the state information of the channel from the eavesdropper to the drone is calculated using the following formula:

[0026]

[0027]

[0028] Where u represents the uth user, and there are U ground users in total; the flight time T is divided into N time slots with T = Nδ, and the duration δ of these time slots is very small, and n represents the nth time slot; d SR[n] Indicates the distance from the base station to the drone, h SR[n] represents the path loss from the base station to the drone, β0 represents the channel energy gain per meter; Indicates the distance from the drone to the user. represents the path loss from the drone to the user; d SE [n] represents the distance from the base station to the eavesdropper, h SE [n] represents the path loss from the base station to the eavesdropper, K is the system parameter constant, σ SE [n] represents a random variable with unit mean exponential distribution (Rayleigh distribution), α is the path loss exponent, and r is the uncertainty range of the eavesdropper. Note: Since the system assumes that the eavesdropper is on the ground, and the channel from the eavesdropper to the base station is constructed by small-scale Rayleigh fading; represents the distance from the drone to the eavesdropper, h RD [n] represents the path loss from the drone to the eavesdropper; (x s ,y s ,0), (x R (n),y R (n),h R [n]), (x e ,y e ,0) respectively represent the location of the base station, the location of the u-th user, the real-time location of the relay drone, and the location of the e-th eavesdropper.

[0029] Furthermore, the calculation method of the safety capacity is as follows:

[0030] First, the following formula is used to calculate the signal-to-noise ratio from the drone to the user and the signal-to-noise ratio from the drone to the eavesdropper:

[0031]

[0032]

[0033] The following formula is used to calculate the signal-to-noise ratio of the channel from the eavesdropper to the base station and from the base station to the drone:

[0034]

[0035]

[0036] At this time, the signal-to-noise ratio of the main channel and the eavesdropping channel is substituted into the following formula to calculate the main channel capacity and the eavesdropping channel capacity:

[0037]

[0038]

[0039] Subtract the main channel capacity from the eavesdropping channel capacity to get a user's instantaneous security capacity, and then minimize the average security capacity expression to get the worst-case security rate:

[0040]

[0041] Effect of introducing propulsion power:

[0042]

[0043]

[0044]

[0045] Where v[n] is the instantaneous rate of the UAV in the nth time slot relative to the uth user, and a u [n] is the instantaneous acceleration of the UAV relative to the uth user in the nth time slot, c1 and c2 are constants that depend on the weight of the UAV, air density, etc., g is the gravity constant, Δk is the kinetic energy constant, which is affected by the starting and ending positions of the velocity; σ 2 is the power of the Gaussian white noise.

[0046] Therefore, the security energy efficiency of the communication system is

[0047] The beneficial effects of the present invention are: improving the robustness of the algorithm, maximizing energy efficiency and improving the security energy efficiency of drone-enabled mobile relays while taking into account the existence of multiple eavesdroppers, ensuring safe communications of aerial or ground drones in remote areas where the base station is located, and ensuring the energy consumption management of drones, which is more in line with actual conditions. Moreover, drones as mobile relays have the advantages of low cost and high operability. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The present invention will be further described below in conjunction with the accompanying drawings.

[0049] Attached Figure 1 A system model diagram used in the method of the present invention;

[0050] Attached Figure 2 The basic flow chart of the method of the present invention is shown in FIG. DETAILED DESCRIPTION

[0051] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings of the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0052] Attached Figure 1 , 2 This is a specific embodiment of the present invention. The invention provides a robust relay secure communication method for drones serving multiple users, which specifically includes the following steps:

[0053] Obtain the location and channel status information of users and base stations accessing the drone network;

[0054] Obtain the location and channel status information of each eavesdropper;

[0055] Calculate the path loss from the drone to the base station and to the receiving end based on the location of the base station and the user;

[0056] According to the location of the eavesdropper, calculate the path loss from the eavesdropper to the base station and to the drone;

[0057] The channel capacity of the eavesdropping channel is calculated based on the path loss from the drone to the eavesdropper;

[0058] Calculate the channel capacity of the main channel based on the path loss from the drone to the user;

[0059] The propulsion power of the drone is calculated based on the real-time speed and acceleration of the drone. Since the propulsion power is much greater than the power of transmitting information, the total energy consumption is the propulsion power.

[0060] The security capacity is calculated based on the difference between the main channel capacity and the eavesdropping channel capacity, and the security energy efficiency is calculated by the quotient of the security capacity and the energy consumption.

[0061] Furthermore, the channel status information is the channel properties of the communication links between the base station and the drone and between the drone and the user in the drone communication network, and the channel properties are mainly line-of-sight propagation loss; the channel status information of the eavesdropper is constructed, and the channel status information is the channel properties of the communication links from the eavesdropper to the base station and from the eavesdropper to the drone, and the channel properties are non-line-of-sight propagation loss and line-of-sight propagation loss respectively.

[0062] Furthermore, the channel state information from the base station to the drone is calculated using the following formula:

[0063]

[0064]

[0065] Furthermore, the channel state information from the drone to the user is calculated using the following formula:

[0066]

[0067]

[0068] Furthermore, the channel state information from the base station to the eavesdropper is calculated using the following formula:

[0069]

[0070]

[0071] Furthermore, the state information of the channel from the eavesdropper to the drone is calculated using the following formula:

[0072]

[0073]

[0074] Where u represents the uth user, and there are U ground users in total; the flight time T is divided into N time slots with T = Nδ, and the duration δ of these time slots is very small, and n represents the nth time slot; d SR[n] Indicates the distance from the base station to the drone, h SR[n] represents the path loss from the base station to the drone, β0 represents the channel energy gain per meter; Indicates the distance from the drone to the user. represents the path loss from the drone to the user; d SE [n] represents the distance from the base station to the eavesdropper, h SE [n] represents the path loss from the base station to the eavesdropper, K is the system parameter constant, σ SE [n] denotes a random variable with unit mean exponential distribution (Rayleigh distribution), α is the path loss exponent, and r is the uncertainty range of the eavesdropper.

[0075] Note: Since the system assumes that the eavesdropper is on the ground, and the channel from the eavesdropper to the base station is constructed by small-scale Rayleigh fading; represents the distance from the drone to the eavesdropper, h RD [n] represents the path loss from the drone to the eavesdropper; (x s ,y s ,0), (x R (n),y R (n),h R [n]), (x e ,y e,0) respectively represent the location of the base station, the location of the u-th user, the real-time location of the relay drone, and the location of the e-th eavesdropper.

[0076] Furthermore, the calculation method of the safety capacity is as follows:

[0077] First, the following formula is used to calculate the signal-to-noise ratio from the drone to the user and the signal-to-noise ratio from the drone to the eavesdropper:

[0078]

[0079]

[0080] The following formula is used to calculate the signal-to-noise ratio of the channel from the eavesdropper to the base station and from the base station to the drone:

[0081]

[0082]

[0083] At this time, the signal-to-noise ratio of the main channel and the eavesdropping channel is substituted into the following formula to calculate the main channel capacity and the eavesdropping channel capacity:

[0084]

[0085]

[0086] Subtract the main channel capacity from the eavesdropping channel capacity to get a user's instantaneous security capacity, and then minimize the average security capacity expression to get the worst-case security rate:

[0087]

[0088] Effect of introducing propulsion power:

[0089]

[0090]

[0091]

[0092] Where v[n] is the instantaneous rate of the UAV in the nth time slot relative to the uth user, and a u [n] is the instantaneous acceleration of the UAV relative to the uth user in the nth time slot, c1 and c2 are constants that depend on the weight of the UAV, air density, etc., g is the gravity constant, Δk is the kinetic energy constant, which is affected by the starting and ending positions of the velocity; σ 2 is the power of the Gaussian white noise.

[0093] Therefore, the security energy efficiency of the communication system is

[0094] The invention provides a robust relay secure communication method for drones to serve multiple users, as shown in the attached Figure 1 As shown in the figure, a drone acts as a mobile relay to build a network for multiple ground users that cannot be covered by the base station and for aerial users with limited activity range. There are eavesdropping devices on the ground, and there may be multiple eavesdropping devices. At this time, the eavesdropping channel that is most likely to affect communication must be considered in real time, the distance between the drone and each node is calculated, the path loss of each main channel is calculated, and then the channel security capacity is calculated. The security capacity at this time is a non-convex problem. The original problem is transformed into a convex problem with the help of alternating iteration, block coordinate descent method, introduction of relaxation variables and other methods. The convex problem at this time is solved with the help of existing convex optimization tools. Since there is only one enabled drone, frequency division multiplexing access is considered when multiple users access. This system considers the worst case eavesdropping, that is, the situation that most affects communication among multiple eavesdroppers; taking into account the user with the worst reception, the user's location or eavesdropping situation is different, so considering the worst user is more robust; maximizing the security performance of the weakest receiving user in the worst case, taking into account the energy consumption of the drone and the transmission power of the jammer.

[0095] The present invention is not limited to the above-mentioned embodiments. Anyone should know that any technical solution identical or similar to the present invention made under the inspiration of the present invention shall fall within the protection scope of the present invention.

[0096] The techniques, shapes, and structural parts not described in detail in the present invention are all well-known techniques.

Claims

1. A robust relay secure communication method for unmanned aerial vehicle serving multiple users, characterized in that: The specific steps include: Obtain the location and channel status information of users and base stations accessing the drone network; Obtain the location and channel status information of each eavesdropper; Calculate the path loss from the drone to the base station and to the receiving end based on the location of the base station and the user; According to the location of the eavesdropper, calculate the path loss from the eavesdropper to the base station and to the drone; The channel capacity of the eavesdropping channel is calculated based on the path loss from the drone to the eavesdropper; Calculate the channel capacity of the main channel based on the path loss from the drone to the user; The propulsion power of the drone is calculated based on the real-time speed and acceleration of the drone. Since the propulsion power is much greater than the power of transmitting information, the total energy consumption is the propulsion power. The security capacity is calculated based on the difference between the main channel capacity and the eavesdropping channel capacity, and the security energy efficiency is calculated by the quotient of the security capacity and the energy consumption; The channel status information is the channel attribute of the communication link between the base station and the drone and the drone and the user in the drone communication network, and the channel attribute is the line-of-sight propagation loss; the channel status information of the eavesdropper is constructed, and the channel status information is the channel attribute of the communication link from the eavesdropper to the base station and the eavesdropper to the drone, and the channel attributes are non-line-of-sight propagation loss and line-of-sight propagation loss respectively; The channel state information from the base station to the drone is calculated using the following formula: The channel state information from the drone to the user is calculated using the following formula: The channel state information from the base station to the eavesdropper is calculated using the following formula: The channel status information from the eavesdropper to the drone is calculated using the following formula: Where u represents the uth user, and there are U ground users in total; the flight time T is divided into N time slots with T = Nδ, and the duration δ of these time slots is very small, and n represents the nth time slot; d SR [n] represents the distance from the base station to the drone, h SR [n] represents the path loss from the base station to the drone, and β0 represents the channel energy gain per meter; Indicates the distance from the drone to the user. represents the path loss from the drone to the user; d SE [n] represents the distance from the base station to the eavesdropper, h SE [n] represents the path loss from the base station to the eavesdropper, K is the system parameter constant, σ SE [n] represents a random variable with unit mean exponential distribution, α is the path loss exponent, and r is the uncertainty range of the eavesdropper, since the system assumes that the eavesdropper is on the ground and the channel from the eavesdropper to the base station is constructed by small-scale Rayleigh fading; represents the distance from the drone to the eavesdropper, h RD [n] represents the path loss from the drone to the eavesdropper; (x s ,y s ,0), (x R (n),y R (n),h R [n]), (x e ,y e ,0) respectively represent the location of the base station, the location of the u-th user, the real-time location of the relay drone, and the location of the e-th eavesdropper; The safety capacity calculation method is as follows: First, the following formula is used to calculate the signal-to-noise ratio from the drone to the user and the signal-to-noise ratio from the drone to the eavesdropper: The following formula is used to calculate the signal-to-noise ratio of the channel from the eavesdropper to the base station and from the base station to the drone: At this time, the signal-to-noise ratio of the main channel and the eavesdropping channel is substituted into the following formula to calculate the main channel capacity and the eavesdropping channel capacity: Subtract the main channel capacity from the eavesdropping channel capacity to get a user's instantaneous security capacity, and then minimize the average security capacity expression to get the worst-case security rate: Effect of introducing propulsion power: in, is the instantaneous rate of the UAV in the nth time slot relative to the uth user, is the instantaneous acceleration of the UAV relative to the uth user in the nth time slot, c1 and c2 are constants that depend on the weight of the UAV and the air density, g is the gravity constant, Δk is the kinetic energy constant, which is affected by the starting and ending positions of the velocity; σ 2 is the power of the Gaussian white noise.

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