A method for secure communication of unmanned aerial vehicle assisted cooperative jamming in a bidirectional wiretapping channel

Abstract

The application discloses a kind of unmanned aerial vehicle assisted cooperative interference security communication methods in two-way eavesdropping channel, including communication both sides Alice and Bob, eavesdropper Eve and the unmanned aerial vehicle of sending interference signal, the present application relates to the technical field of secure communication.The two-way eavesdropping channel unmanned aerial vehicle assisted cooperative interference security communication, by jointly optimizing the transmission power of both sides in two-way channel, the interference power and flight trajectory of unmanned aerial vehicle maximum security capacity of communication system, the power distribution and flight trajectory optimization scheme under unmanned aerial vehicle cooperative interference assisted security communication system are proposed, and the lower bound of the achievable security rate in the process of unmanned aerial vehicle flight under the constraint of average transmission power and maximum transmission power is obtained, so an effective suboptimal algorithm is proposed using block coordinate descent method and continuous convex optimization, effectively improve the communication security of communication system, jointly optimize legal user power, unmanned aerial vehicle interference power and flight trajectory to prevent eavesdropper from eavesdropping useful information.

Description

Technical Field

[0001] This invention relates to the field of secure communication technology, specifically to a method for secure communication using unmanned aerial vehicle (UAV)-assisted cooperative interference in a two-way eavesdropping channel. Background Technology

[0002] Communication security differs from information security. It is security based on the signal layer and does not involve specific data content. Communication security is the foundation of information security, providing physical guarantees for the correct and reliable transmission of information. Unmanned aerial vehicles (UAVs) are unmanned aircraft controlled by radio remote control equipment and their own program control devices. UAVs are actually a general term for unmanned aerial vehicles, which can be divided into several categories from a technical perspective: unmanned helicopters, unmanned fixed-wing aircraft, unmanned multi-rotor aircraft, unmanned airships, and unmanned paragliders.

[0003] There are significant security risks in existing channels, including the risk of two-way eavesdropping. The transmission of information cannot be adequately protected, leading to the leakage of a large amount of important information. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for secure communication through UAV-assisted collaborative interference in a two-way eavesdropping channel. This method solves the problem of the risk of being eavesdropped on from both sides, the inability to adequately guarantee and protect the security of transmitted information, and the resulting leakage of a significant amount of important information.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for secure communication using drone-assisted cooperative interference in a two-way eavesdropping channel, comprising Alice and Bob as the communicating parties, Eve as the eavesdropper, and a drone transmitting interference signals, wherein the locations of the ground users are known. , and The drone flies at a fixed altitude of H. For ease of analysis, the drone's flight time is divided into N time slots, each time slot being... ,Right now ,make Represents the set of discrete time slots, with the UAV's horizontal coordinate set as... And satisfy the following constraints: 1a

[0006] 1b

[0007] Set the initial and final positions of the drone as follows: and Furthermore, since line-of-sight communication is used, the channel gain between Alice, Bob, and Eve and the drone can be expressed as:

[0008] 2a

[0009] 2b

[0010] 2c

[0011] make , This represents the average power of Alice and Bob at time slot n. Let the interference power of the drone be represented. Then the power constraints for the interference transmitted by Alice, Bob, and the drone are as follows:

[0012] , 3a

[0013] , 3b

[0014] 3C

[0015] Therefore, the average achievable communication rate between Alice and Bob can be expressed as:

[0016] ,

[0017] Using a bidirectional channel, the achievable communication rate for all legitimate users of the entire communication system can be expressed as:

[0018]

[0019] The achievable communication rate for eavesdropping on user Eve can be expressed as:

[0020] .

[0021] Therefore, the security capacity of a communication system can be expressed as:

[0022] (4)

[0023] in, The drone's flight trajectory is set in the nth time slot as follows: User power is , , ,

[0024] Therefore, this optimization problem can be represented as P1:

[0025] (5)

[0026] Due to the nonconvexity of (P1) and the discrete constraints, it is difficult to solve. Therefore, to simplify this problem, and They are replaced by their upper and lower bounds, respectively.

[0027] (6)

[0028] (7)

[0029] (8)

[0030] in .

[0031] Therefore, P1 can be simplified to P2.

[0032] P2: (9).

[0033] Preferably, in equations (1a) and (1b), , It is the drone's maximum speed, because It is small enough that the drone can be considered stationary in each time slot.

[0034] Preferably, in equations 2a, 2b, and 2c, the channel between Alice and Bob can be considered as independent Rayleigh fading, and the channel gain can be expressed as... Similarly, the relationships between Alice and Eve, and between Bob and Eve, can be represented as... and , Indicates that at the reference distance is Wireless channel power gain at that time The path fading index, and They are all independent exponentially distributed random variables with unit expected value.

[0035] Preferably, in formulas 3a, 3b and 3c, , and .

[0036] Preferably, in equation (6), , , , .

[0037] Preferably, sub-problem 1: Optimization, when given , and Then, P2 can be represented as P3:

[0038] (10)

[0039] in, , , , .

[0040] Although (P3) is nonconvex, its optimal solution can be expressed as:

[0041] (11)

[0042] in, (12)

[0043] It is a guarantee The non-negative value of can be found using the binary search method.

[0044] Preferably, sub-problem 2: The optimization uses a bidirectional channel, so the power optimization for Bob is the same as for Alice, meaning P2 can be represented as P4:

[0045] (13)

[0046] in, , , , .

[0047] The formula in subproblem 1 can be used to find it.

[0048] Preferably, sub-problem 3: Optimization, making , , , , , , .

[0049] Given transmission power , and flight trajectory At that time, P2 can be described as P5:

[0050] (14)

[0051] make As the UAV interference power for the kth iteration, because equation (14) is related to If the function is convex, then

[0052] , 15a

[0053] , 15b

[0054] in, , , , .,

[0055] In conclusion, P5 can be approximated as P6:

[0056] (16).

[0057] Preferably, the sub-problem 4: UAV trajectory Optimization, for a given transmission power , , By introducing , and P2 can be described as P7:

[0058]

[0059] From the above formula, it can be seen that when constraints 20b, 20c, and 20d are satisfied, P7 can obtain the optimal solution. Using the SCO theorem... , , and Transformed into their respective convex upper bounds, Given the initial trajectory for the k-th iteration, we can obtain:

[0060] , 21a

[0061] , 21b

[0062] , 22a

[0063] , 22b

[0064] in, ,

[0065] ,

[0066] , , , , ,

[0067] Substituting 21 and 22 into P7, P8 can be expressed as:

[0068]

[0069] It is important to note that P8 has been transformed into a convex problem, and therefore it can be effectively solved using the convex optimization toolbox. Similarly, the upper bounds used in (21) and (22) ensure that the solution to P8 is a subset of P7. In summary, given... When the solution obtained from P8 is obtained, the suboptimal solution of P7 can be obtained.

[0070] Beneficial effects

[0071] This invention provides a method for secure communication using UAV-assisted cooperative interference in a two-way eavesdropping channel. Compared with existing technologies, it has the following advantages: In this method, the locations of ground users are known, and they are respectively... , and The drone flies at a fixed altitude of H. For ease of analysis, the drone's flight time is divided into N time slots, each time slot being... ,Right now ,make Represents the set of discrete time slots, with the UAV's horizontal coordinate set as... This paper proposes a power allocation and flight trajectory optimization scheme for a UAV cooperative interference-assisted secure communication system by jointly optimizing the transmission power of both communicating parties, the interference power of the UAV, and the flight trajectory in a two-way channel to maximize the security capacity of the communication system. The analysis yields a lower bound on the achievable safe rate of the UAV during flight under the constraints of average transmission power and maximum transmission power. Therefore, an effective suboptimal algorithm is proposed using the block coordinate descent method and continuous convex optimization to transform this non-convex problem into a convex problem, effectively improving the communication security of the communication system. The joint optimization of the legitimate user power, UAV interference power, and flight trajectory prevents eavesdroppers from intercepting useful information and improves the security performance of the communication system. At the same time, the flight time is long enough to ensure that the UAV can fly closer to the eavesdropper to exert stronger interference. Attached Figure Description

[0072] Figure 1 This is a diagram of the two-way eavesdropping channel model for UAV-assisted jamming in this invention. Detailed Implementation

[0073] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0074] Please see Figure 1 This invention provides a technical solution: a method for secure communication using drone-assisted cooperative interference in a two-way eavesdropping channel, comprising Alice and Bob as the communicating parties, Eve as the eavesdropper, and a drone transmitting interference signals. The locations of the ground users are known. , and The drone flies at a fixed altitude of H. For ease of analysis, the drone's flight time is divided into N time slots, each time slot being... ,Right now ,make Represents the set of discrete time slots, with the UAV's horizontal coordinate set as... And satisfy the following constraints: 1a

[0075] 1b

[0076] Set the initial and final positions of the drone as follows: and Furthermore, since line-of-sight communication is used, the channel gain between Alice, Bob, and Eve and the drone can be expressed as:

[0077] 2a

[0078] 2b

[0079] 2c

[0080] make , This represents the average power of Alice and Bob at time slot n. Let the interference power of the drone be represented. Then the power constraints for the interference transmitted by Alice, Bob, and the drone are as follows:

[0081] , 3a

[0082] , 3b

[0083] 3C

[0084] Therefore, the average achievable communication rate between Alice and Bob can be expressed as:

[0085] ,

[0086] Using a bidirectional channel, the achievable communication rate for all legitimate users of the entire communication system can be expressed as:

[0087]

[0088] The achievable communication rate for eavesdropping on user Eve can be expressed as:

[0089] ,

[0090] Therefore, the security capacity of a communication system can be expressed as:

[0091] (4)

[0092] in, The drone's flight trajectory is set in the nth time slot as follows: User power is , , .

[0093] Therefore, this optimization problem can be represented as P1:

[0094] 5

[0095] Due to the non-convexity of P1 and the discrete constraints, this problem is difficult to solve. Therefore, to simplify this problem, and They are replaced by their upper and lower bounds, respectively.

[0096] (6)

[0097] (7)

[0098] (8)

[0099] in .

[0100] Therefore, (P1) can be simplified to (P2).

[0101] (P2): (9).

[0102] In this invention, in formulas 1a and 1b, , It is the drone's maximum speed, because It is small enough that the drone can be considered stationary in each time slot.

[0103] In this invention, in equations 2a, 2b, and 2c, the channel between Alice and Bob can be considered as an independent Rayleigh fading, and the channel gain can be expressed as... Similarly, the relationships between Alice and Eve, and between Bob and Eve, can be represented as... and , Indicates that at the reference distance is Wireless channel power gain at that time The path fading index, and They are all independent exponentially distributed random variables with unit expected value.

[0104] In this invention, in formulas 3a, 3b and 3c, , and .

[0105] In this invention, in formula (6), , , , .

[0106] In this invention, sub-problem 1: Optimization, when given , and Then, P2 can be represented as P3:

[0107] (10)

[0108] in, , , , .

[0109] Although (P3) is nonconvex, its optimal solution can be expressed as:

[0110] (11)

[0111] in, (12)

[0112] It is a guarantee The non-negative value of can be found using the binary search method.

[0113] In this invention, sub-problem 2: The optimization uses a bidirectional channel, so the power optimization for Bob is the same as for Alice, meaning P2 can be represented as P4:

[0114] (13)

[0115] in, , , , .

[0116] The formula in subproblem 1 can be used to find it.

[0117] In this invention, sub-problem 3: Optimization, making , , , , , , .

[0118] Given transmission power , and flight trajectory At that time, P2 can be described as P5:

[0119] (14)

[0120] make As the UAV interference power for the kth iteration, because equation (14) is related to If the function is convex, then

[0121] , 15a

[0122] , 15b

[0123] in, , , , .,

[0124] In conclusion, P5 can be approximated as P6:

[0125] (16).

[0126] In this invention, sub-problem 4: UAV trajectory Optimization, for a given transmission power , , By introducing , and P2 can be described as P7:

[0127]

[0128] From the above formula, it can be seen that when constraints 20b, 20c, and 20d are satisfied, P7 can obtain the optimal solution. Using the SCO theorem... , , and Transformed into their respective convex upper bounds, Given the initial trajectory for the k-th iteration, we can obtain:

[0129] , 21a

[0130] , 21b

[0131] , 22a

[0132] , 22b

[0133] in, ,

[0134] ,

[0135] , , , , ,

[0136] Substituting (21) and (22) into P7, P8 can be expressed as:

[0137]

[0138] It is important to note that P8 has been transformed into a convex problem, and therefore it can be effectively solved using the convex optimization toolbox. Similarly, the upper bounds used in (21) and (22) ensure that the solution to P8 is a subset of P7. In summary, given... When the solution obtained from P8 is obtained, the suboptimal solution of P7 can be obtained.

[0139] Furthermore, any content not described in detail in this specification is existing technology known to those skilled in the art.

[0140] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0141] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for secure communication using drone-assisted cooperative jamming in a two-way eavesdropping channel, comprising Alice and Bob as the communicating parties, Eve as the eavesdropper, and a drone transmitting jamming signals, characterized in that: The locations of the ground users are known, namely: , and The drone flies at a fixed altitude of H. For ease of analysis, the drone's flight time is divided into N time slots, each time slot being... ,Right now ,make Represents the set of discrete time slots, with the UAV's horizontal coordinate set as... And satisfy the following constraints: (1a) (1b) Set the initial and final positions of the drone as follows: and Furthermore, since line-of-sight communication is used, the channel gain between Alice, Bob, and Eve and the drone can be expressed as: (2a) (2b) (2c) make , This represents the average power of Alice and Bob at time slot n. Let the interference power of the drone be represented. Then the power constraints for the interference transmitted by Alice, Bob, and the drone are as follows: , (3a) , (3b) , (3c) Therefore, the average achievable communication rate between Alice and Bob can be expressed as: 、 Using a bidirectional channel, the achievable communication rate for all legitimate users of the entire communication system can be expressed as: The achievable communication rate for eavesdropping on user Eve can be expressed as: ， Therefore, the security capacity of a communication system can be expressed as: （4） in, The drone's flight trajectory is set in the nth time slot as follows: User power is , , ; Therefore, this optimization problem can be represented as P1: (5) Due to the non-convexity of P1 and the discrete constraints, this problem is difficult to solve. Therefore, to simplify this problem, and They are replaced by their upper and lower bounds, respectively. (6) , (7) ,(8) in ; Therefore, P1 can be simplified to P2. P2: (9)； In equations 1a and 1b, , It is the drone's maximum speed, because It is small enough that the drone can be considered stationary in each time slot.

2. The method for secure communication using UAV-assisted cooperative interference in a two-way eavesdropping channel according to claim 1, characterized in that: In equations (2a), (2b), and (2c), the channel between Alice and Bob can be considered as an independent Rayleigh fading, and the channel gain can be expressed as... Similarly, the relationships between Alice and Eve, and between Bob and Eve, can be represented as... and , Indicates that at the reference distance is Wireless channel power gain at that time The path fading index, and They are all independent exponentially distributed random variables with unit expected value.

3. The method for secure communication using UAV-assisted cooperative interference in a two-way eavesdropping channel according to claim 2, characterized in that: In equations (3a), (3b) and (3c), , and .

4. The method for secure communication using UAV-assisted cooperative interference in a two-way eavesdropping channel according to claim 3, characterized in that: In the aforementioned formula (6), , , , .

5. A method for secure communication using unmanned aerial vehicle (UAV)-assisted cooperative interference in a two-way eavesdropping channel according to claim 4, characterized in that: Subproblem 1: Optimization, when given , and Then, P2 can be represented as P3: (10) in, , , , ; Although P3 is nonconvex, its optimal solution can be expressed as: (11) in, (12) It is a guarantee The non-negative value of can be found using the binary search method.

6. A method for secure communication using unmanned aerial vehicle (UAV)-assisted cooperative interference in a two-way eavesdropping channel according to claim 5, characterized in that: Subproblem 2: The optimization uses a bidirectional channel, so the power optimization for Bob is the same as for Alice, meaning P2 can be represented as P4: (13) in, , , , . The formula in subproblem 1 can be used to find it.

7. A method for secure communication using unmanned aerial vehicle (UAV)-assisted cooperative interference in a two-way eavesdropping channel according to claim 6, characterized in that: Sub-problem 3: Optimization, making , , , , , , , Given transmission power , and flight trajectory Then, P2 can be described as P5: (14) make As the UAV interference power in the kth iteration, because equation (14) is related to If the function is convex, then , (15a) , (15b) in, , , , ., In conclusion, P5 can be approximated as P6: (16)。 8. A method for secure communication using unmanned aerial vehicle (UAV)-assisted cooperative interference in a two-way eavesdropping channel according to claim 7, characterized in that: Sub-problem 4: Drone trajectory Optimization, for a given transmission power , , By introducing , and P2 can be described as P7: From the above formula, it can be seen that when constraints (20b), (20c), and (20d) are equal, P7 can obtain the optimal solution. Using the SCO theorem... , , and Transformed into their respective convex upper bounds, Given the initial trajectory for the k-th iteration, we can obtain: , (21a) , (21b) , (22a) , (22b) in, , , , , , , ， Substituting (21) and (22) into P7, P8 can be expressed as: 。

Images