An anti-interference method and system based on relay location selection and power allocation

Abstract

An embodiment of the present invention provides an anti-interference method based on relay position selection and power allocation, which is used in a communication scenario including a sending end, a receiving end, and a relay node for relay communication between the sending end and the receiving end. The method includes: obtaining the positions of the sending end, the receiving end, and the interfering end to determine the optimal relay node position for anti-interference; when the sending end sends a real signal to the receiving end, scheduling the relay node at the optimal relay node position and transmitting the real signal in stages in the following manner: The first sending stage: the sending end sends a real signal to the relay node and sends a first spoofing signal in the direction of the interfering end; The second sending stage: the relay node sends the real signal received in the first sending stage to the receiving end. At the same time, the sending end sends a second spoofing signal in the direction of the interfering end, and the transmission power of the second spoofing signal is greater than that of the first spoofing signal.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technologies, and in particular, to an anti-interference method and system based on relay position selection and power allocation. Background Art

[0002] Due to the open nature of wireless signals, while wireless communication technologies facilitate people's lives, they also face serious noise interference problems. Once a communication signal is interfered with, it will pose a serious threat to the reliability of communication transmission, and the two communication parties may not even be able to complete normal information transmission. Especially in rapidly changing and complex anti-interference communication scenarios, such as anti-interference drill scenarios and battlefield communication environments that require anti-interference drills, when the communication signals of the sending and receiving parties are strongly interfered with, information transmission failures will occur, threatening the entire battlefield situation. Therefore, the problem of wireless communication anti-interference is an important issue faced in modern battlefield communication.

[0003] In some cases, the direct communication link between the sending end and the target receiving end faces a serious threat from the interfering end. When the sending end and the receiving end cannot communicate normally due to the influence of the interfered link, the interference can be effectively countered by increasing the power of the sending end on the direct link. However, with the enhancement of the interference ability of the interfering end, guiding the jammer to generate more powerful interference in the corresponding frequency band. At this time, if only the power of the direct link is increased to counter the interference, it will seriously affect the data transmission ability of the legitimate communication parties.

[0004] To improve the anti-interference ability of a communication system, taking the solution described in the document with the publication number CN114172691A and the invention title "An anti-tracking interference system based on a decoy strategy" as an example, this solution uses a third-party node to send decoy signals, making the power of the decoy signals received by the interfering end greater than that of the actual communication signals, confusing the interfering end into interfering with the decoy signals. However, it does not consider the situation when the legitimate communication party cannot complete effective intercommunication with the third-party node. In this case, the third-party node cannot correctly receive the decoy communication instructions from the legitimate communication party, and thus cannot carry out decoy communication work. Taking the solution described in the document with the publication number CN115514447A and the invention title "Signal sending end method, signal receiving method and system for anti-tracking interference" as an example, it solves the problem of inability to complete effective intercommunication with the third-party node by using the sending end to send actual signals and decoy signals simultaneously. However, when the direct link is interfered by obstacles or irresistible factors, the communication of the direct link will still be severely interfered, and the power of the actual signal and the decoy signal is allocated using the index of the maximum throughput, resulting in a high probability that the actual signal can still be monitored by the interfering end. To address the above problems, the prior art also uses relay nodes that are not contaminated or less contaminated by the interfering end to forward the information of the sending end to the target receiving end. Taking the solution described in the document with the publication number CN114268903A and the invention title "A method for deploying and power allocating the position of an unmanned aerial vehicle relay assisted by geographical information" as an example, this solution is for an orthogonal frequency division multiple access downlink transmission system with an unmanned aerial vehicle as a relay, considering and avoiding the occlusion of the communication link by buildings to establish a line-of-sight channel, and improving the capacity of the communication system by optimizing the position and power allocation of the unmanned aerial vehicle. However, this solution does not consider the problem of the optimal position and power allocation of the unmanned aerial vehicle in an interference environment. Taking the solution described in the document with the publication number CN115473545A and the invention title "Anti-interference wireless communication method and system for network beam collaborative hopping" as an example, this solution only considers the position of the relay node selected when the throughput of the receiving end is the largest, without considering the relative positions among the position of the relay node it selects, the position of the sending end, and the position of the interfering end. This not only may cause a certain degree of interference when the sending end sends signals, making the relay node unable to receive the real signal and affecting communication, but also does not consider the situation of decoy communication of the relay node to the interfering end when sending the real signal, and also causes interference when the relay node set at this position sends signals to the receiving end, resulting in poor anti-interference communication effects for both legitimate communication parties.

[0005] Therefore, how to perform power allocation and select the position of the relay node in an interference environment so that the legitimate communication party can effectively resist interference and ensure data transmission ability is an urgent problem to be solved. Summary of the Invention

[0006] Therefore, the object of the present invention is to overcome the defects of the above-mentioned prior art and provide an anti-interference method and system based on relay position selection and power allocation.

[0007] The object of the present invention is achieved by the following technical solutions:

[0008] According to a first aspect of the present invention, there is provided an anti-interference method based on relay position selection and power allocation, which is used in a communication scenario including a sending end, a receiving end, and a relay node for relaying communication between the sending end and the receiving end. The method includes: obtaining the positions of the sending end, the receiving end, and the interfering end to determine the optimal relay node position for anti-interference; when the sending end sends a real signal to the receiving end, scheduling the relay node at the optimal relay node position and transmitting the real signal in stages as follows: the first sending stage: the sending end sends the real signal to the relay node and sends a first spoofing signal in the direction of the interfering end; the second sending stage: the relay node sends the real signal received in the first sending stage to the receiving end. At the same time, the sending end sends a second spoofing signal in the direction of the interfering end, and the transmission power of the second spoofing signal is greater than the transmission power of the first spoofing signal.

[0009] In some embodiments of the present invention, before the first sending stage, the beam direction of the real signal sent by the sending end, the transmission power of the real signal, and the transmission power of the first spoofing signal are determined in advance; the beam direction of the real signal is determined based on the minimum gain value of the beam of the real signal of the sending end to the direction of the interfering end. Among them, the optimal relay node position is the position found in the beam direction of the real signal that maximizes the transmission rate of the real signal; the transmission power of the real signal and the transmission power of the first spoofing signal are determined based on the condition that the power of the first spoofing signal received by the interfering end calculated is greater than the power of the real signal received by the interfering end calculated and a preset spoofing success probability threshold.

[0010] In some embodiments of the present invention, the determination method of the beam direction of the real signal includes: according to the positions of the sending end and the interfering end, determining the beam direction of the first spoofing signal sent by the sending end in the direction of the interfering end; based on the beam direction of the first spoofing signal, determining the horizontal angle and pitch angle corresponding to the beam direction of the real signal by calculating the minimum gain value of the beam of the real signal to the direction of the interfering end, and obtaining the beam direction of the real signal according to the calculated horizontal angle and pitch angle.

[0011] In some embodiments of the present invention, when there are multiple beam directions for the true signal that satisfy the minimum gain value, the method for determining the horizontal angle and elevation angle corresponding to the beam direction of the true signal includes: calculating the optimal relay node position and the transmission power of the true signal determined corresponding to each beam direction according to the horizontal angle and elevation angle corresponding to each beam direction among the multiple beam directions; obtaining the transmission rate of the true signal corresponding to the optimal relay node position in each beam direction according to the optimal relay node position and the transmission power of the true signal in each beam direction; comparing the transmission rates corresponding to each beam direction, and selecting the horizontal angle and elevation angle of the beam direction corresponding to the maximum transmission rate as the horizontal angle and elevation angle of the finally determined beam direction of the true signal.

[0012] In some embodiments of the present invention, the calculation method of the minimum gain value is as follows:

[0013]

[0014] Where Z represents the minimum gain value, represents the conjugate transpose of the array response vector related to β of the uniform linear array, the subscript ULA represents the uniform linear array, the superscript H represents the conjugate transpose, and β 0 represents the angle between the beam direction of the first spoofing signal and the y-axis on the uniform planar array UPA, and a 0 represents the angle between the beam direction of the true signal and the y-axis on the uniform planar array UPA, a ULA (β x ) represents the array response vector related to β of the uniform linear array, β x represents the angle between the beam direction of the true signal and the y-axis on the uniform planar array UPA, x represents the angle between the beam direction of the true signal and the y-axis on the uniform planar array UPA, The symbol represents the Kronecker product, represents the conjugate transpose of the array response vector related to θ of the uniform linear array, θ 0 represents the elevation angle of the beam direction of the first spoofing signal, and aULA(θx) represents the array response vector related to θ of the uniform linear array, θ 0 represents the elevation angle of the beam direction of the true signal, θ x represents the elevation angle of the beam direction of the true signal, θ x represents the elevation angle of the beam direction of the true signal.

[0015] In some embodiments of the present invention, the method for determining the transmission power of the true signal and the transmission power of the first spoofing signal includes: based on a preset spoofing success probability threshold and the beam direction of the true signal, using the dichotomy method to allocate the total transmission power of the transmitter, obtaining the maximum transmission power of the true signal under the spoofing success probability threshold, and using the maximum transmission power as the transmission power of the true signal; obtaining the transmission power of the first spoofing signal according to the difference between the total transmission power and the maximum transmission power, wherein transmitting the true signal based on the beam direction and transmission power of the true signal and transmitting the spoofing signal based on the transmission power of the spoofing signal satisfy that the power of the first spoofing signal received by the interfering end is greater than the power of the true signal received by it.

[0016] In some embodiments of the present invention, the method for finding the position that maximizes the transmission rate of the true signal in the beam direction of the true signal includes: obtaining the position of the receiving end, and adjusting the distances between the position of the relay node and the position of the transmitter and the position of the receiving end respectively in the beam direction of the true signal; obtaining a first average signal-to-noise ratio function for calculating the true signal transmitted from the transmitter to the relay node based on the adjusted distance between the position of the relay node and the position of the transmitter; obtaining a second average signal-to-noise ratio function for calculating the true signal transmitted from the relay node to the receiving end based on the adjusted distance between the position of the relay node and the position of the transmitter; and determining an optimal relay node position of the relative transmitter position on the beam direction of the true signal that maximizes the transmission rate of the true signal according to whether there is a solution for the abscissa of the relay node position when the difference between the calculated first average signal-to-noise ratio function and the second average signal-to-noise ratio function is zero.

[0017] In some embodiments of the present invention, when there is no solution for the abscissa of the relay node position, the abscissa of the optimal relay node position relative to the transmitter position is determined by a preset first abscissa calculation method, and the ordinate and height of the optimal relay node position are obtained according to the abscissa of the optimal relay node position and the horizontal angle and elevation angle of the beam direction of the true signal, wherein the first abscissa calculation method is calculated as follows:

[0018]

[0019] where x * represents the abscissa of the optimal relay node position, represents the first average signal-to-noise ratio function, represents the second average signal-to-noise ratio function, L represents the abscissa of the receiving end position relative to the transmitter position, θ x represents the elevation angle of the beam direction of the true signal, represents the horizontal angle of the beam direction of the true signal.

[0020] In some embodiments of the present invention, when there is a solution for the abscissa of the relay node position, the abscissa of the optimal relay node position relative to the transmitter position is determined by a preset second abscissa calculation method. The ordinate and height of the optimal relay node position are obtained based on the abscissa of the optimal relay node position, the horizontal angle and the pitch angle of the beam direction of the real signal. Among them, the second abscissa calculation method is calculated as follows:

[0021]

[0022] Among them, x * represents the abscissa of the optimal relay node position, L represents the abscissa of the receiver position relative to the transmitter position, P 2 represents the transmission power of the first spoofing signal, σ SR represents the noise power received by the relay node, represents the expected value obtained by squaring the sum of the absolute values of all the numerical values of the vector within the symbol and then dividing by the total number of numerical values of the vector, represents the conjugate transpose of the receive beamforming vector of the relay node, represents the conjugate transpose of the receive beamforming vector of the receiver, H RD represents the channel of the relay link between the relay node and the receiver, f RD represents the beamforming vector transmitted by the relay node, P 1 represents the transmission power of the real signal, σ RD represents the noise power received by the receiver, H SR represents the channel of the relay link between the transmitter and the relay node, f SR represents the beamforming vector of the real signal transmitted by the transmitter, θ x represents the pitch angle of the beam direction of the real signal, represents the horizontal angle of the beam direction of the real signal. The superscript H represents the conjugate transpose. The S in the subscripts SR and RD represents the transmitter, the R represents the relay node, and the D represents the receiver.

[0023] In some embodiments of the present invention, the method of transmitting the second spoofing signal in the second transmission stage includes that the transmitter transmits the second spoofing signal in the direction of the interfering end with its total transmission power.

[0024] According to a second aspect of the present invention, there is provided an anti-jamming system based on relay position selection and power allocation, including a sending end, a receiving end, and a relay node for relay communication between the sending end and the receiving end. The sending end is configured to obtain the position of the sending end, the position of the receiving end, and the position of the jamming end to determine the optimal relay node position for anti-jamming, and send a real signal to the receiving end through the relay node; the relay node is configured to receive the real signal sent by the sending end and send the real signal to the receiving end; the receiving end is configured to receive the real signal sent by the relay node; wherein, when the sending end sends a real signal to the receiving end, the relay node is scheduled at the optimal relay node position and the real signal is transmitted in stages in the following manner: The first sending stage: the sending end sends a real signal to the relay node and sends a first spoofing signal in the direction of the jamming end; The second sending stage: the relay node sends the real signal received in the first sending stage to the receiving end. At the same time, the sending end sends a second spoofing signal in the direction of the jamming end, and the transmission power of the second spoofing signal is greater than that of the first spoofing signal.

[0025] Compared with the prior art, the advantages of the present invention are as follows:

[0026] 1. In the first sending stage of the present invention, the sending end sends a real signal to the relay node and sends a first spoofing signal in the direction of the jamming end, and determines the optimal relay node position, so that a good anti-jamming effect is achieved when the sending end sends a real signal to the relay node; in the second sending stage, the relay node sends the real signal received in the first sending stage to the receiving end. At the same time, the sending end sends a second spoofing signal in the direction of the jamming end, and the transmission power of the second spoofing signal is greater than that of the first spoofing signal, making the anti-jamming effect better in the whole relay communication process.

[0027] 2. When determining the optimal relay node position, the present invention directly searches for the position that maximizes the transmission rate of the real signal in the beam direction of the real signal. The optimal relay node position is reduced to searching for the optimal relay node position in one-dimensional space, and uses whether there is a solution for the abscissa of the relay node position when the difference between the first average signal-to-noise ratio function and the second average signal-to-noise ratio function is zero to determine an optimal relay node position relative to the sending end position in the beam direction of the real signal that maximizes the transmission rate of the real signal. The optimal relay node position can be obtained without searching in one-dimensional space, improving the calculation efficiency and ensuring the data transmission efficiency of the calculated optimal relay node position. In addition, based on the set spoofing success probability threshold, the dichotomy method is used to allocate the transmission power of the real signal and the spoofing signal, further improving the anti-jamming communication efficiency and calculation efficiency, and being applicable to rapidly changing and complex anti-jamming communication scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The embodiments of the present invention will be further described below with reference to the accompanying drawings, where:

[0029] Figure 1 It is a schematic diagram of anti-interference communication between a transmitter and a receiver according to an embodiment of the present invention;

[0030] Figure 2 It is a schematic diagram of a selection scheme for the beam direction of the true signal and the beam direction of the spoofing signal at the transmitter according to an embodiment of the present invention;

[0031] Figure 3 It is a schematic diagram of the pattern gain corresponding to four different beam directions according to an embodiment of the present invention;

[0032] Figure 4 It is a schematic diagram of the curve of the spoofing success probability varying with the power allocation ratio in the beam direction that meets the conditions according to an embodiment of the present invention;

[0033] Figure 5 It is a schematic diagram of the variation trend of the transmission rate of the true signal with the distance between the relay node and the transmitter node in an interference environment according to an embodiment of the present invention;

[0034] Figure 6 It is a schematic diagram of the comparison result of the transmission rate (throughput) between the method of the present invention and other frequency hopping schemes in the same interference environment according to an embodiment of the present invention. Specific embodiments

[0035] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below through specific embodiments with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] As mentioned in the background art section, in the existing relay communication system, only the position of the relay node selected when the throughput of the receiver is maximized is considered, and the relative positions among the selected relay node position, the transmitter position and the interferer position are not considered. This not only may cause a certain degree of interference when the transmitter sends a signal, resulting in the relay node not receiving the true signal and affecting communication, but also does not consider the spoofing communication of the relay node to the interferer when sending the true signal, causing a certain degree of interference in the process of the relay node sending the signal to the receiver, resulting in poor anti-interference communication effects for both legitimate communication parties.

[0037] To address the above problems, the present invention provides an anti-interference method based on relay location selection and power allocation, which is applicable to a communication scenario including a transmitter, a receiver, and a relay node for relaying communication between the transmitter and the receiver. First, the present invention determines the optimal relay node location for anti-interference by obtaining the locations of the transmitter, the receiver, and the interfering node, and selects an optimal relay node location that is as little interfered by the interfering node as possible considering the locations of the transmitter, the receiver, and the interfering node, so as to achieve anti-interference relay communication. Finally, when the transmitter sends a real signal to the receiver, the relay node is scheduled at the optimal relay node location and the real signal is transmitted in two transmission stages. Specifically, in the first transmission stage, the transmitter sends the real signal to the relay node and a first spoofing signal in the direction of the interfering node. That is, the beam of the real signal is aligned with the direction of the location of the relay node, and the beam of the first spoofing signal is aligned with the direction of the location of the interfering node, which can ensure that the power of the first spoofing signal received by the interfering node is the largest, effectively protecting the transmitted real signal and achieving a good anti-interference effect. In the second transmission stage, the relay node sends the real signal received in the first transmission stage to the receiver. At the same time, the transmitter sends a second spoofing signal in the direction of the interfering node, and the transmission power of the second spoofing signal is greater than that of the first spoofing signal, so as to ensure that the power of the spoofing signal received by the interfering node in the second transmission stage is greater than the power of the real signal sent from the relay node, inducing the interfering node to continuously interfere with the spoofing signal in the second transmission stage. The present invention sets the relay node at the optimal relay node location for anti-interference and performs anti-interference on both transmission stages, improving the anti-interference performance in the entire relay communication process.

[0038] To better understand the present invention, the following will specifically describe each transmission stage in detail with reference to the accompanying drawings and specific embodiments.

[0039] According to an embodiment of the present invention, an anti-interference method based on relay location selection and power allocation is provided. Refer to Figure 1 , which is applicable to a communication scenario including a transmitter S, a receiver D, and a relay node R for relaying communication between the transmitter S and the receiver D. The method includes: obtaining the locations of the transmitter S, the receiver D, and the interfering node J to determine the optimal relay node location for anti-interference; when the transmitter S sends a real signal to the receiver D through relay link 1 and relay link 2, scheduling the relay node R at the optimal relay node location and transmitting the real signal in two stages, namely the first transmission stage and the second transmission stage, as follows.

[0040] The first transmission stage: The transmitting end sends a real signal to the relay node and a first spoofing signal in the direction of the interfering end. According to an embodiment of the present invention, before the first transmission stage, the beam direction of the real signal sent by the transmitting end, the transmission power of the real signal, and the transmission power of the first spoofing signal are determined in advance.

[0041] According to an embodiment of the present invention, the beam direction of the real signal is determined based on the minimum gain value from the beam of the real signal of the transmitting end to the direction of the interfering end. Among them, the optimal relay node position is the position found in the beam direction of the real signal that maximizes the transmission rate of the real signal.

[0042] According to an embodiment of the present invention, see Figure 2 , Figure 2 is the selection scheme for the beam direction of the real signal of the transmitting end and the beam direction of the spoofing signal. Among them, the determination method of the beam direction of the real signal includes: determining the beam direction of the first spoofing signal sent by the transmitting end in the direction of the interfering end according to the position of the transmitting end and the position of the interfering end. Among them, the beam direction of the first spoofing signal sent in the first transmission stage is the same as the beam direction of the second spoofing signal sent in the second transmission stage, and is represented by the beam direction of the spoofing signal in Figure 2 . Based on the beam direction of the first spoofing signal, the horizontal angle and elevation angle corresponding to the beam direction of the real signal are determined by calculating the minimum gain value from the beam of the real signal to the direction of the interfering end, and the beam direction of the real signal is obtained according to the calculated horizontal angle and elevation angle. For example, a Uniform Planar Array (UPA) is adopted, and a three-dimensional coordinate system of the x-axis, y-axis, and z-axis is established. θ x represents the elevation angle of the beam direction of the real signal, represents the horizontal angle of the beam direction of the real signal. The horizontal angle and elevation angle of the beam direction of the real signal are solved by calculating the minimum gain value.

[0043] According to an embodiment of the present invention, the calculation method of the minimum gain value is as follows:

[0044]

[0045] Among them, Z represents the minimum gain value, represents the conjugate transpose of the array response vector related to β 0 of the uniform linear array, the subscript ULA represents the uniform linear array, and the superscript H represents the conjugate transpose. β 0 represents the angle between the beam direction of the first spoofing signal and the y-axis on the uniform planar array UPA. a ULA (β x ) represents the array response vector related to β x of the uniform linear array, and β xDenote the angle between the beam direction of the real signal and the y-axis on the uniform planar array (UPA). The symbol ⊗ represents the Kronecker product. Denote the conjugate transpose of the array response vector related to the uniform linear array and θ 0 θ 0 Denote the elevation angle of the beam direction of the first spoofing signal. aULA(θx) represents the array response vector related to the uniform linear array and θ x θ x Denote the elevation angle of the beam direction of the real signal.

[0046] According to an embodiment of the present invention, the method for solving the horizontal angle and elevation angle of the beam direction of the real signal by calculating the minimum gain value is as follows:

[0047] First, according to the uniform planar array, it is known that the antenna elements at the transmitting end are located in the yoz plane. Assume that the number of antennas in the y-axis direction is W, and the number of antennas in the z-axis direction is Y. Then, the beamforming vector of the real signal at the transmitting end can be expressed as:

[0048]

[0049] where, T represents the transpose of the beamforming vector, j represents the imaginary part, n represents the antenna element index in the z-axis direction 0, 1, 2, Y - 1, m represents the antenna element index in the y-axis direction 0, 1, 2, W - 1, and β x related to θ x and satisfy the relationship:

[0050] Secondly, let the minimum gain value be zero, and the following relational expression is obtained:

[0051]

[0052] where, is the horizontal angle of the beam direction of the first spoofing signal (from the transmitting end to the interfering end), θ 0 is the elevation angle of the beam direction of the first spoofing signal, is the horizontal angle of the beam direction of the real signal.

[0053] Then, according to formula (2) and formula (3), the result of the following formula (4) is further obtained, and the horizontal angle and elevation angle θ of the beam direction of the real signal are calculated according to the result of formula (4) x . Where, formula (4) is as follows:

[0054]

[0055] where, when in formula (4) and When the above equation holds, expand it The following expansion formula (5) can be obtained:

[0056]

[0057] Solve the expansion formula (5) to obtain the angle β between the beam direction of the true signal and the y-axis x :

[0058]

[0059] Similarly, solve it in the same way as above The elevation angle θ of the beam direction of the true signal can be obtained x :

[0060]

[0061] Finally, according to the relationship formula (3), formulas (6) and (7), the horizontal angle is obtained

[0062]

[0063] According to the above solution method, one or more sets of elevation angles and horizontal angles can be obtained

[0064] According to an embodiment of the present invention, when given the positions of the transmitting end, relay node and interfering end, and only one set of elevation angle and horizontal angle is obtained, it means that there is only one beam direction of the true signal that satisfies the minimum gain value condition. Use this set of elevation angle and horizontal angle as the elevation angle and horizontal angle corresponding to the finally determined beam direction of the true signal

[0065] According to an embodiment of the present invention, when given the positions of the transmitting end, relay node and interfering end, and multiple sets of elevation angles and horizontal angles are obtained, it means that there are multiple beam directions of the true signal that satisfy the minimum gain value. Select the elevation angle and horizontal angle corresponding to one of the multiple beam directions of the true signal that meet the conditions as the elevation angle and horizontal angle of the finally determined beam direction of the true signal. As Figure 3 shown Figure 3 is a schematic diagram of the directional pattern gain corresponding to four different beam directions. The direction indicated by the arrow corresponding to each directional pattern gain is the direction where the gain of the beam of the true signal in this direction is 0, that is, this direction is the direction of the interfering end relative to the transmitting end (the beam direction of the spoofing signal), and the direction with the maximum gain is the direction of the relay node relative to the transmitting end (the beam direction of the true signal), Figure 3 indicating that there are four beam directions of the true signal that satisfy the minimum gain value condition. At this time, one of the four beam directions of the true signal that meet the conditions can be selected as the finally determined beam direction of the true signal

[0066] According to an embodiment of the present invention, when there are multiple beam directions of the true signal satisfying the minimum gain value, the horizontal angle and the pitch angle corresponding to the beam direction of the true signal are determined according to the following steps a1, a2, and a3:

[0067] In step a1, according to the horizontal angle and the pitch angle corresponding to each beam direction among the multiple beam directions, the optimal relay node position on each beam direction and the transmission power of the true signal determined corresponding to this direction are calculated.

[0068] In step a2, according to the optimal relay node position on each beam direction and the transmission power of the true signal, the transmission rate of the true signal corresponding to the optimal relay node position on each beam direction is obtained.

[0069] In step a3, the horizontal angle and the pitch angle of the beam direction corresponding to the maximum transmission rate are selected as the horizontal angle and the pitch angle of the beam direction of the finally determined true signal by comparing the transmission rates corresponding to each beam direction.

[0070] According to an embodiment of the present invention, when there is only one beam direction of the true signal satisfying the minimum gain value condition, only a position where the transmission rate of the true signal is the maximum needs to be found on the beam direction of the true signal satisfying the condition as the optimal relay node position, the relay node is set at this position, and the corresponding transmission power of the true signal is determined. When there are multiple beam directions of the true signal satisfying the minimum gain value, an optimal relay node position is found on each of the multiple beam directions, and the transmission power of the true signal corresponding to each beam direction is determined to obtain the transmission rate of the true signal corresponding to each beam direction. One beam direction corresponding to the maximum transmission rate is selected as the finally determined beam direction of the true signal. And the relay node is set at the optimal relay node position on this beam direction. The present invention makes the gain value of the true signal transmitted from the transmitting end to the direction of the interfering end zero by reasonably designing the beam direction of the true signal, and determines the transmission power of the true signal corresponding to the beam direction of the true signal. The beam direction of the spoofing signal is the direction where the spoofing signal is aligned with the interfering end, which can ensure that the power of the spoofing signal received by the interfering end is the maximum, effectively protect the transmitted true signal, and improve the anti-interference performance of both legitimate communication parties. At the same time, the relay node is set at the optimal relay node position on the corresponding beam direction to improve the transmission rate of the true signal.

[0071] According to an embodiment of the present invention, after calculating one or more beam directions that meet the conditions, for the beam direction of each true signal to be selected, it is necessary to determine the transmission power of the true signal corresponding to the beam direction of the true signal and the transmission power of the first spoofing signal. Among them, the transmission power of the true signal and the transmission power of the first spoofing signal are determined based on the condition that the power of the first spoofing signal received by the calculated interfering end is greater than the power of the true signal received by the calculated interfering end and a preset spoofing success probability threshold.

[0072] According to an embodiment of the present invention, the method for determining the transmission power of the true signal and the transmission power of the first spoofing signal includes: based on a preset spoofing success probability threshold, using the dichotomy method to allocate the total transmission power of the transmitting end to obtain the maximum transmission power of the true signal under the spoofing success probability threshold, and using the maximum transmission power as the transmission power of the true signal; obtaining the transmission power of the first spoofing signal according to the difference between the total transmission power and the maximum transmission power. Among them, transmitting the true signal based on the beam direction of the true signal and the transmission power of the true signal and transmitting the spoofing signal based on the transmission power of the spoofing signal satisfy the condition that the power of the first spoofing signal received by the interfering end is greater than the power of the true signal received by it. The present invention uses the dichotomy method to allocate the transmission power of the true signal and the spoofing signal based on the set spoofing success probability threshold, reduces the computational complexity of power allocation, and can set the spoofing success probability threshold according to actual needs, such as setting it to 0.91, 0.96, 0.98, etc., with high flexibility. And determining the transmission power of the true signal and the spoofing signal under the limited spoofing success probability threshold ensures the anti-interference effect of both legitimate communication parties. And by allocating the total transmission power by the dichotomy method, for example, the total transmission power is 0.1W, the transmission power of the true signal is set to 0.05W by the dichotomy method, and it is verified whether the spoofing of the interfering end is successful. If successful, continue to set the transmission power of the true signal to 0.75W in this way to obtain the maximum transmission power of the true signal under the spoofing success probability threshold, further improving the calculation efficiency to be applicable to the ever-changing and complex anti-interference communication scenario.

[0073] According to an embodiment of the present invention, the method for finding the position where the transmission rate of the true signal is maximized (i.e., the optimal relay node position corresponding to the beam direction) in the beam direction of the true signal includes steps b1, b2, b3, and b4:

[0074] In step b1, obtain the position of the receiving end, and adjust the distances between the relay node position and the transmitting end position and the distance between the relay node position and the receiving end position in the beam direction of the true signal.

[0075] According to an embodiment of the present invention, first, represent the three-dimensional coordinates of the relay node position. Denote the relay node position as QR (x, y, h), when the beam direction of the true signal is determined, i.e., the elevation angle θ x and the horizontal angle are determined, the position Q of the relay node R in (x, y, h), y and h can be expressed in terms of x, θ x and as follows: y is expressed as follows:

[0076]

[0077] h is expressed as follows:

[0078]

[0079] According to the above-obtained formulas (9) and (10), the position Q of the relay node R (x, y, h) is expressed as Based on the three-dimensional representation result of the final relay node position, the present invention directly searches for the position on the beam direction of the true signal that maximizes the transmission rate of the true signal, and thus θ x and can be determined. At this time, only x needs to be calculated, so that the search for the optimal relay node position in the three-dimensional space is reduced to the search for the optimal relay node position in the one-dimensional space, improving the calculation efficiency and ensuring the data transmission efficiency of the searched optimal relay node position.

[0080] Secondly, according to the three-dimensional coordinates of the relay node position represented above, the distances between the transmitter position and the relay node position, and between the relay node position and the receiver position are represented. For example, based on the Cartesian coordinate system, referring to Figure 2 , the positions of the transmitter and the receiver are respectively denoted as Q S (0, 0, 0) and Q D (L, 0, 0), and the position of the interfering node is denoted as Q J (x J , y J , z J ).

[0081] The distance between the transmitter position and the relay node position can be expressed as: Let f 1 (x) = d SR 2 , then we get:

[0082]

[0083] The distance between the relay node position and the receiver position can be expressed as: Let f 2 (x) = d RD2 , we get:

[0084]

[0085] Finally, based on the above formulas (11) and (12), the constructed first average signal-to-noise ratio function and second average signal-to-noise ratio function are obtained.

[0086] In step b2, a first average signal-to-noise ratio function for calculating the true signal sent from the sending end to the relay node is obtained based on the distance between the adjusted relay node position and the sending end position.

[0087] According to an embodiment of the present invention, the first average signal-to-noise ratio function is constructed as follows:

[0088] Taking Figure 1 as an example, in relay link 1, the number of transmitting antennas at the sending end is set to N S , the number of antennas at the relay node for receiving the true signal from the sending end and the number of antennas for the true signal to the receiving end are both set to N R , and the number of antennas at the receiving end for receiving the true signal sent by the relay node is N D . The sending end sends a true signal to the relay node, and the received signal at the relay node is expressed as:

[0089]

[0090] where ρP S is the transmission power of the true signal of the sending end in relay link 1, P S is the total transmission power of the sending end, is the zero-mean additive white Gaussian noise (AWGN) received at the relay node, σ SR represents the noise power of the relay node, represents N R ×N R identity matrix, f SR is the beamforming vector of the true signal of the sending end in the direction of relay link 1, s represents the true information symbol sent by the sending end, and is expressed as the conjugate transpose of the receiving beamforming vector of the relay node, and the superscript H represents the conjugate transpose. H SR is the channel of relay link 1. Therefore, the received signal-to-noise ratio γ SR at the relay node is expressed as:

[0091]

[0092] where, is the average power gain corresponding to different distances, c 0is the path loss at a reference distance of 1 m, and α is the path loss exponent. Finally, the first average signal-to-noise ratio function is obtained according to Equation (14):

[0093]

[0094] where represents the expected value obtained by dividing the square of the sum of the absolute values of all the numerical values of the vector within the symbol by the total number of numerical values of the vector.

[0095] Taking Figure 1 as an example, in Relay Link 2, in the same manner as described above, the second average signal-to-noise ratio function can be obtained:

[0096]

[0097] where γ RD represents the received signal-to-noise ratio at the receiving end, represents the conjugate transpose of the received beamforming vector at the receiving end, and the superscript H represents the conjugate transpose, H RD is the channel of Relay Link 2, f RD is the beamforming vector for the relay node to send the true signal in the direction of Relay Link 2, and σ RD represents the noise power at the receiving end. The subscripts S in the above symbols SR and subscript RD represent the sending end, R represents the relay node, and D represents the receiving end.

[0098] In step b3, a second average signal-to-noise ratio function for calculating the true signal sent by the relay node to the receiving end is obtained based on the distance between the adjusted relay node position and the sending end position.

[0099] In step b4, according to whether there is a solution for the abscissa of the relay node position when the difference between the calculated first average signal-to-noise ratio function and the second average signal-to-noise ratio function is zero, the optimal relay node position relative to the sending end position that maximizes the transmission rate of the true signal is determined. By adjusting the relay node position in the determined beam direction of the true signal and determining a position in this beam direction that maximizes the transmission rate of the true signal, the search in three-dimensional space is reduced to one-dimensional, reducing the computational complexity, improving the computational efficiency, and ensuring the data transmission efficiency.

[0100] According to an embodiment of the present invention, when determining a position in the beam direction that maximizes the transmission rate of the true signal, the following calculation formula for the maximum value of the transmission rate of the true signal needs to be constructed based on the first average signal-to-noise ratio function and the second average signal-to-noise ratio function:

[0101]

[0102]

[0103] Among them, R max represents the maximum transmission rate, represents solving the abscissa at the maximum transmission rate, x represents the abscissa, s.t represents the constraint condition, L represents the coordinate of the receiver's position relative to the transmitter's position on the X-axis, y represents the coordinate of the relay node's position relative to the transmitter's position on the Y-axis, h represents the height of the relay node's position relative to the transmitter's position, P S cheat represents the transmission power of the first spoofing signal, P S real represents the transmission power of the real signal, P S represents the total transmission power, ρ represents the ratio of the transmission power of the real signal to the total transmission power, represents the successful spoofing probability of the real spoofing, represents the power of the first spoofing signal received by the interfering end, represents the power of the real signal received by the interfering end, p represents the preset threshold of the successful spoofing probability.

[0104] Based on the above formula (17) for calculating the maximum value of the transmission rate of the real signal, the process of deriving the optimal relay node position is as follows:

[0105] First of all, due to the monotonicity of the logarithmic function and the complex function, it can be known that the monotonicity of formula (17) is the same as that of its first average signal-to-noise ratio function and the second average signal-to-noise ratio function , and the monotonicity of the first average signal-to-noise ratio function and the second average signal-to-noise ratio function depends on f 1 (x) and f 2 (x) respectively. Therefore, taking the derivative of f 1 (x), we get:

[0106]

[0107] From formula (18), it can be known that when 0 ≤ x ≤ L, is monotonically decreasing.

[0108] Similarly, taking the derivative of f 2 (x), we can get:

[0109]

[0110] From formula (19), it can be known that when , is monotonically increasing; when , is monotonically decreasing.

[0111] Through the analysis of the above embodiments, the following function monotonicity results can be obtained:

[0112]

[0113] According to an embodiment of the present invention, based on the monotonicity results of the first average signal-to-noise ratio function and the second average signal-to-noise ratio function in the above table, the optimal solution of the abscissa of the relay node position is obtained, and the obtained abscissa can maximize the transmission rate of the true signal. For example, by discussing whether there is a solution for the abscissa of the relay node position when the difference between the first average signal-to-noise ratio function and the second average signal-to-noise ratio function is zero, the optimal solution of the abscissa that maximizes the transmission rate of the true signal is calculated. The present invention determines an optimal relay node position relative to the transmitter position on the beam direction of the true signal that maximizes the transmission rate of the true signal by calculating whether there is a solution for the abscissa of the relay node position when the difference between the first average signal-to-noise ratio function and the second average signal-to-noise ratio function is zero, and can obtain the optimal relay node position without searching in one-dimensional space, improving the calculation efficiency.

[0114] According to an embodiment of the present invention, when there is no solution for the abscissa of the relay node position, the abscissa of the optimal relay node position relative to the transmitter position is determined by a preset first abscissa calculation method, and the ordinate and height of the optimal relay node position are obtained based on the abscissa of the optimal relay node position and the horizontal angle and elevation angle of the beam direction of the true signal. Among them, the first abscissa calculation method is calculated as follows:

[0115]

[0116] Among them, x * represents the abscissa of the optimal relay node position, and L represents the abscissa of the receiver position relative to the transmitter position.

[0117] According to an embodiment of the present invention, when there is a solution for the abscissa of the relay node position, the abscissa of the optimal relay node position relative to the transmitter position is determined by a preset second abscissa calculation method, and the ordinate and height of the optimal relay node position are obtained based on the abscissa of the optimal relay node position and the horizontal angle and elevation angle of the beam direction of the true signal. Among them, the second abscissa calculation method is calculated as follows:

[0118]

[0119] Among them, x * represents the abscissa of the optimal relay node position, L represents the abscissa of the receiver position relative to the transmitter position, P 2Indicates the transmission power of the first spoofing signal, P 1 Indicates the transmission power of the real signal.

[0120] In summary, according to the limiting conditions, a set of horizontal angles and pitch angles of the beam direction of the real signal that meet the conditions is determined. For each set of horizontal angles and pitch angles in the set, the bisection method is used to determine the transmission power of the real signal that meets the set spoofing success probability threshold constraint; then the optimal deployment position of the relay node is determined. For each set of angles in the set, an optimal relay node position and the corresponding transmission rate can be obtained. Finally, the optimal relay node position corresponding to the maximum transmission rate among all the optional beam directions of the real signal is taken to improve the anti-interference performance of the legitimate communication parties and ensure the data transmission efficiency.

[0121] The second transmission stage: The relay node sends the real signal received in the first transmission stage to the receiving end. At the same time, the sending end sends a second spoofing signal in the direction of the interfering end, and the transmission power of the second spoofing signal is greater than that of the first spoofing signal. To ensure that the spoofing signal power received by the interfering end in the second transmission stage is greater than the real signal power sent from the relay node received, inducing the interfering end to continuously interfere with the spoofing signal, effectively protecting the transmitted real signal, and further improving the anti-interference performance of the legitimate communication parties.

[0122] According to an embodiment of the present invention, the method of sending the second spoofing signal in the second transmission stage includes the sending end sending the second spoofing signal in the direction of the interfering end with its total transmission power.

[0123] According to an embodiment of the present invention, an anti-interference system based on relay position selection and power allocation is provided, including a sending end, a receiving end, and a relay node for relay communication between the sending end and the receiving end. The sending end is used to obtain the positions of the sending end, the receiving end, and the interfering end to determine the optimal relay node position for anti-interference, and send the real signal to the receiving end through the relay node; the relay node is used to receive the real signal sent by the sending end and send the real signal to the receiving end; the receiving end is used to receive the real signal sent by the relay node; wherein, when the sending end sends the real signal to the receiving end, the relay node is scheduled at the optimal relay node position and the real signal is transmitted in stages in the following manner: The first transmission stage: The sending end sends the real signal to the relay node and sends a first spoofing signal in the direction of the interfering end; The second transmission stage: The relay node sends the real signal received in the first transmission stage to the receiving end. At the same time, the sending end sends a second spoofing signal in the direction of the interfering end, and the transmission power of the second spoofing signal is greater than that of the first spoofing signal.

[0124] To verify the anti-interference effect of the present invention, the inventor conducts simulation verification on the present invention to Figure 2The established Cartesian coordinate system and communication system are described, and the specific simulation parameters are shown in Table 1.

[0125] Table 1: Description of Simulation Parameters for Anti-Jamming Method

[0126]

[0127]

[0128] First, based on the above simulation parameters and the anti-jamming method of the present invention, the beam patterns of real signals that meet the conditions are determined. There are five beam patterns of real signals that meet the minimum gain value condition. After determining the beam direction of the real signal from the transmitter to the relay node, at each beam direction, the dichotomy method is used to determine the optimal power allocation ratio that meets the condition of successful spoofing (i.e., the ratio of the transmission power of the real signal to the total transmission power). As shown in Table 2 below, where the condition for successful spoofing is that the probability that the power of the spoofing signal received by the jammer is greater than the power of the received real signal is greater than the set spoofing success probability threshold p.

[0129] Table 2: Beam Directions of Real Signals Meeting the Conditions and Corresponding Optimal Power Allocation Ratios

[0130]

[0131] The power allocation ratios of each beam direction that meet the conditions are searched by a search method (e.g., exhaustive search method) to verify the correctness of using the dichotomy method. The simulation results of determining the five beam directions by the search method are as Figure 4 shown, Figure 4 is the curve of the spoofing success probability changing with the power allocation ratio on the beam direction that meets the conditions. Among them, the abscissa is the ratio of the actual signal power (the ratio of the transmission power of the real signal to the total transmission power), the ordinate is the spoofing success probability, and the black horizontal line on the coordinate system is a preset spoofing success probability threshold p = 0.96. It can be seen that the power allocation ratios obtained by the dichotomy method and the exhaustive search method are the same, but the complexity is lower.

[0132] Finally, through the above embodiments, the optimal relay node positions on each beam direction that meet the conditions are determined. Theoretically, the corresponding optimal relay node positions are calculated for each of the above five beam directions that meet the conditions, as shown in Table 3 below:

[0133] Table 3: Beam Directions of Real Signals Meeting the Conditions and Corresponding Optimal Relay Node Positions

[0134]

[0135]

[0136] The above theoretical derivation results are verified by the exhaustive search method, and the corresponding simulation results are as Figure 5 shown, Figure 5 To track the changing trend of the transmission rate of the real signal with the distance between the relay node and the sending node in an interference environment, the abscissa is the distance between the relay node and the sending end, and the ordinate is the overall throughput of the relay link (i.e., the transmission rate of the real signal passing through relay link 1 and relay link 2). Figure 5 For the case of the beam direction that meets the conditions and the optimal power allocation ratio in this direction, the simulation results of the transmission rate of different relay node positions from the sending end obtained by the exhaustive search method are shown. The black circles are the optimal relay node positions in the beam direction that meet the conditions obtained by the method of the present invention. Therefore, the globally optimal point of the theoretical derivation is the pitch angle of 79° and the horizontal angle of 12°. Then, the beam direction corresponding to the pitch angle of 79° and the horizontal angle of 12° is selected as the finally determined beam direction of the real signal. According to Figure 5 the simulation results, there are five beam directions that meet the conditions under the current simulation parameters; for each beam direction, a deception success probability threshold of 0.96 is given, and the proportion of the deception signal power corresponding to each beam direction is calculated. Further, based on the beam direction and power allocation ratio of the real signal at the sending end, the optimal relay node position and the corresponding rate in each direction can be calculated, and the optimal relay node position corresponding to the maximum transmission rate in the five directions is taken as the final optimal relay node position; the derived theoretical value is consistent with the simulation results, which proves the accuracy of the theoretical analysis.

[0137] Finally, to prove the superiority of the proposed scheme, as Figure 6 shown, Figure 6 it is the comparison result of the transmission rate (throughput) between the method of the present invention and other frequency hopping schemes in the same interference environment. Figure 6 The abscissa is the total transmission power of the sending end, and the abscissa is the corresponding throughput. Under the condition of different total transmission powers W of the sending end, Scheme 1 is executed: the anti-interference method using the optimal relay position (i.e., the optimal relay node position) and the optimal power allocation ratio of the present invention, Scheme 2 is executed: the method using the optimal relay position but not the optimal power allocation ratio, Scheme 3 is executed: the method using the non-optimal relay position and the optimal power allocation ratio, and Scheme 4 is executed: the method of directly communicating using the direct link of the non-deception communication scheme. The changing situations of the throughput are obtained respectively. According to the changing situation of the throughput, it shows that in the same tracking interference environment, compared with other traditional frequency hopping schemes, the anti-interference method based on the present invention can significantly improve the communication system rate, indicating the effectiveness of the anti-interference of the present invention.

[0138] It should be noted that although the above steps are described in a specific order, it does not mean that the steps must be executed in the above specific order. In fact, some of these steps can be executed concurrently or even the order can be changed, as long as the required functions can be achieved.

[0139] The present invention may be a system, a method, and / or a computer program product. The computer program product may include a computer-readable storage medium having thereon computer-readable program instructions for causing a processor to implement various aspects of the present invention.

[0140] The computer-readable storage medium may be a tangible device that retains and stores instructions for use by an instruction execution device. The computer-readable storage medium may include, for example, but is not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer-readable storage medium include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disc (DVD), a memory stick, a floppy disk, a mechanically encoded device such as a punched card or raised structures in grooves having instructions stored thereon, and any suitable combination of the foregoing.

[0141] The embodiments of the present invention have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The choice of terms used herein is intended to best explain the principles of the embodiments, the practical application, or improvements made to the technology in the market, or to enable other ordinary skill in the art in the technical field to understand the embodiments disclosed herein.

Claims

1. An anti-jamming method based on relay location selection and power allocation, which is used in a communication scenario including a sending end, a receiving end, and a relay node for relaying communication between the sending end and the receiving end. Characterized in that, This method includes: Obtain the positions of the sending end, the receiving end, and the interfering end to determine the optimal relay node position for anti-jamming; When the sending end sends a real signal to the receiving end, schedule the relay node at the optimal relay node position and transmit the real signal in stages as follows: The first sending stage: The sending end sends a real signal to the relay node and sends a first spoofing signal in the direction of the interfering end; The second sending stage: The relay node sends the real signal received in the first sending stage to the receiving end. At the same time, the sending end sends a second spoofing signal in the direction of the interfering end, and the transmission power of the second spoofing signal is greater than the transmission power of the first spoofing signal; Among them, the optimal relay node position is the position found in the beam direction of the real signal that maximizes the transmission rate of the real signal. The method for finding the position that maximizes the transmission rate of the real signal in the beam direction of the real signal includes: Obtain the position of the receiving end, and adjust the distances between the relay node position and the sending end position and the receiving end position respectively in the beam direction of the real signal; Obtain a first average signal-to-noise ratio function for calculating the real signal sent from the sending end to the relay node based on the distance between the adjusted relay node position and the sending end position; Obtain a second average signal-to-noise ratio function for calculating the real signal sent from the relay node to the receiving end based on the distance between the adjusted relay node position and the sending end position; According to whether there is a solution for the abscissa of the relay node position when the difference between the calculated first average signal-to-noise ratio function and the second average signal-to-noise ratio function is zero, determine an optimal relay node position relative to the sending end position in the beam direction of the real signal that maximizes the transmission rate of the real signal.

2. The method according to claim 1, Characterized in that, Before the first sending stage, the beam direction of the real signal sent by the sending end, the transmission power of the real signal, and the transmission power of the first spoofing signal are determined in advance; The beam direction of the real signal is determined based on the minimum gain value from the beam of the real signal of the sending end to the interfering end direction; The transmission power of the real signal and the first spoofing signal are determined under the condition that the power of the first spoofing signal received by the interfering end calculated is greater than the power of the real signal received by the interfering end calculated and a preset spoofing success probability threshold.

3. The method according to claim 2, Characterized in that, The determination method of the beam direction of the real signal includes: According to the positions of the sending end and the interfering end, determine the beam direction of the first spoofing signal sent by the sending end to the interfering end direction; Based on the beam direction of the first spoofing signal, determine the horizontal angle and pitch angle corresponding to the beam direction of the real signal by calculating the minimum gain value from the beam of the real signal to the interfering end direction, and obtain the beam direction of the real signal according to the calculated horizontal angle and pitch angle.

4. The method according to claim 3, Characterized in that, When there are multiple beam directions of the true signal that satisfy the minimum gain value, the method for determining the horizontal angle and elevation angle corresponding to the beam direction of the true signal includes: According to the horizontal angle and elevation angle corresponding to each beam direction among the multiple beam directions, calculate the optimal relay node position on each beam direction and the transmission power of the true signal determined corresponding to this direction; According to the optimal relay node position and the transmission power of the true signal on each beam direction, obtain the transmission rate of the true signal corresponding to the optimal relay node position on each beam direction; Compare the transmission rates corresponding to each beam direction, and select the horizontal angle and elevation angle of the beam direction corresponding to the maximum transmission rate as the horizontal angle and elevation angle of the finally determined beam direction of the true signal.

5. The method according to claim 3, wherein, the calculation method of the minimum gain value is as follows: where Z represents the minimum gain value, denotes the conjugate transpose of the array response vector related to the uniform linear array and β 0 The subscript ULA represents the uniform linear array, and the superscript H represents the conjugate transpose. β 0 denotes the angle between the beam direction of the first spoofing signal and the y-axis on the uniform planar array UPA. a ULA (β x ) represents the array response vector related to the uniform linear array and β x β x denotes the angle between the beam direction of the true signal and the y-axis on the uniform planar array UPA. The symbol ⊗ represents the Kronecker product. denotes the conjugate transpose of the array response vector related to the uniform linear array and θ 0 θ 0 denotes the elevation angle of the beam direction of the first spoofing signal. a ULA (θ x ) represents the array response vector related to the uniform linear array and θ x θ x denotes the elevation angle of the beam direction of the true signal.

6. The method according to claim 2, wherein, the determination method of the transmission power of the true signal and the transmission power of the first spoofing signal includes: Based on a preset spoofing success probability threshold and the beam direction of the true signal, use the bisection method to allocate the total transmission power of the sending end to obtain the maximum transmission power of the true signal under the spoofing success probability threshold, and use the maximum transmission power as the transmission power of the true signal; Obtain the transmission power of the first spoofing signal according to the difference between the total transmission power and the maximum transmission power, wherein sending the true signal based on the beam direction and transmission power of the true signal and sending the spoofing signal based on the transmission power of the spoofing signal satisfy that the power of the first spoofing signal received by the interfering end is greater than the power of the true signal received by it.

7. The method according to claim 6, wherein, when the abscissa of the relay node position has no solution, determine the abscissa of the optimal relay node position relative to the position of the sending end through a preset first abscissa calculation method, and obtain the ordinate and height of the optimal relay node position according to the abscissa of the optimal relay node position and the horizontal angle and elevation angle of the beam direction of the true signal, wherein the first abscissa calculation method is calculated as follows: Among them, x * represents the abscissa of the optimal relay node position, represents the first average signal-to-noise ratio function, represents the second average signal-to-noise ratio function, L represents the abscissa of the receiver position relative to the transmitter position, θ x represents the pitch angle of the beam direction of the true signal, represents the horizontal angle of the beam direction of the true signal.

8. The method according to claim 6, wherein, when the abscissa of the relay node position has a solution, determine the abscissa of the optimal relay node position relative to the position of the sending end through a preset second abscissa calculation method, and obtain the ordinate and height of the optimal relay node position according to the abscissa of the optimal relay node position and the horizontal angle and elevation angle of the beam direction of the true signal, wherein the second abscissa calculation method is calculated as follows: Among them, x * represents the abscissa of the optimal relay node position, and L represents the abscissa of the receiver position relative to the transmitter position. P 2 represents the transmission power of the first spoofing signal, and σ SR represents the noise power received by the relay node. represents the expected value obtained by dividing the square of the sum of the absolute values of all the values of the vector within this symbol by the total number of values of the vector. represents the conjugate transpose of the receive beamforming vector of the relay node. represents the conjugate transpose of the receive beamforming vector of the receiver, and H RD represents the channel of the relay link between the relay node and the receiver, and f RD represents the beamforming vector transmitted by the relay node, and P 1 represents the transmission power of the real signal, and σ RD represents the noise power received by the receiver, and H SR represents the channel of the relay link between the transmitter and the relay node, and f SR represents the beamforming vector of the real signal transmitted by the transmitter, and θ x represents the elevation angle of the beam direction of the real signal. represents the horizontal angle of the beam direction of the real signal. The superscript H represents the conjugate transpose, and the subscripts SR and RD, where S represents the transmitter, R represents the relay node, and D represents the receiver.

9. The method according to claim 1, wherein, the method of sending the second spoofing signal in the second transmission stage includes that the sending end sends the second spoofing signal towards the interfering end with its total transmission power.

10. An anti-jamming system based on relay position selection and power allocation, including a sending end, a receiving end, and a relay node for relay communication between the sending end and the receiving end, wherein, The transmitting end is used to obtain the positions of the transmitting end, the receiving end, and the interfering end, so as to determine the optimal relay node position for anti-interference, and send the real signal to the receiving end through the relay node; The relay node is used to receive the real signal sent by the transmitting end and send the real signal to the receiving end; The receiving end is used to receive the real signal sent by the relay node; Among them, when the real signal is sent from the transmitting end to the receiving end, the relay node is scheduled at the optimal relay node position and the real signal is transmitted in stages in the following manner: The first transmission stage: The transmitting end sends the real signal to the relay node and sends the first spoofing signal in the direction of the interfering end; The second transmission stage: The relay node sends the real signal received in the first transmission stage to the receiving end. At the same time, the transmitting end sends the second spoofing signal in the direction of the interfering end, and the transmission power of the second spoofing signal is greater than that of the first spoofing signal; Among them, the optimal relay node position is the position found in the beam direction of the real signal that maximizes the transmission rate of the real signal. The method for finding the position that maximizes the transmission rate of the real signal in the beam direction of the real signal includes: Obtain the position of the receiving end, and adjust the distances between the relay node position and the transmitting end position and the receiving end position respectively in the beam direction of the real signal; Obtain the first average signal-to-noise ratio function for calculating the real signal sent from the transmitting end to the relay node based on the distance between the adjusted relay node position and the transmitting end position; Obtain the second average signal-to-noise ratio function for calculating the real signal sent from the relay node to the receiving end based on the distance between the adjusted relay node position and the transmitting end position; According to whether there is a solution for the abscissa of the relay node position when the difference between the calculated first average signal-to-noise ratio function and the second average signal-to-noise ratio function is zero, determine an optimal relay node position relative to the transmitting end position in the beam direction of the real signal that maximizes the transmission rate of the real signal.

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