An active positioning secure communication method based on joint detection

Abstract

The present invention provides an active positioning security communication method based on joint detection, which is applied to a smart grid system. First, a base station identifies an eavesdropper through information fed back by a receiving end. Then, the coordinate information of the eavesdropper is calculated using a least squares algorithm through the positions of multiple base stations and a radio wave path loss model. Targeted defense measures can be implemented by locating the position information of the eavesdropper. Then, the antenna array of a non-communication base station points the beam to the eavesdropper by adjusting the phase and amplitude of each array element, and actively sends interference information to the eavesdropper, thereby reducing the risk of the network being attacked, improving the confidentiality of communications, and realizing secure transmission of smart grid signals. In addition, the active positioning security communication method of the present invention can be applied to line-of-sight and non-line-of-sight scenarios considering multipath effects, has a wider application scenario, and can provide reliable protection for the wireless communication security of smart grids.

Description

Technical Field

[0001] The present invention relates to the technical field of power grid information transmission, and in particular to an active positioning safety communication method based on joint detection. Background Art

[0002] As an important part of smart grid, advanced metering infrastructure usually includes smart meters, communication networks, data management systems, etc., which are used to measure, collect, analyze and transmit information on electricity usage. In recent years, with the continuous advancement of the construction of the ubiquitous power Internet of Things ecosystem, the number of smart meters has ushered in explosive growth. The widespread deployment and application of smart meters have enabled the power system to achieve unprecedented intelligence in data collection, monitoring and user services. At the same time, the rapid development of the fifth-generation mobile communication technology has promoted the application of wireless communications in smart grids.

[0003] At present, research on wireless communication security mainly focuses on the use of technologies such as artificial noise, collaborative interference, beamforming and resource allocation methods. However, these studies rarely consider the impact of the eavesdropper's location on security and cannot provide effective protection for the wireless communication security of smart grids. Summary of the invention

[0004] The purpose of the present invention is to provide an active positioning security communication method based on joint detection, which provides effective protection for the wireless communication security of smart grids.

[0005] An active positioning safety communication method based on joint detection is applied to a smart grid system, wherein the smart grid system includes multiple base stations and multiple receiving terminals;

[0006] The method comprises:

[0007] Step S1, multiple base stations communicate with smart meters in a target area to obtain signal characteristics and corresponding coordinate information of the smart meters in the target area. The signal characteristics of the smart meters include a receiving frequency range of the smart meters. When multiple receiving ends receive signals, it is determined whether the receiving frequency range of the receiving end is within the receiving frequency range of the smart meters.

[0008] Step S2: if the receiving frequency range of the receiving end is within the receiving frequency range of the smart meter, the receiving end is determined to be a smart meter, and a base station closest to the smart meter is selected to establish a communication connection with the smart meter; if the receiving frequency range of the receiving end is not within the receiving frequency range of the smart meter, the receiving end is marked as an illegal receiver, and step S3 is executed;

[0009] Step S3, the base station transmits the feedforward permission information to the illegal receiver via wireless communication, and determines whether the illegal receiver is an eavesdropper based on the information fed back by the illegal receiver. If the illegal receiver is an eavesdropper, step S4 is executed;

[0010] Step S4, the eavesdropper establishes a communication connection with the base station, the base station obtains the received signal strength and the transmitted signal power of the eavesdropper, and according to the radio wave path loss model, sets the signal to satisfy the log-normal shadow model, calculates the distance from the base station to the eavesdropper, and then uses the least squares algorithm to solve the coordinate information of the eavesdropper according to the positions of multiple base stations;

[0011] In step S5, the data processing center shares the coordinate information of the eavesdropper to all base stations through the power lines, marks the base stations that have established communication connections with the smart meters as communication base stations, and marks the base stations that have not established communication connections with the smart meters as non-communication base stations. The antenna array of the non-communication base station points the beam to the eavesdropper by adjusting the phase and amplitude of each array element, thereby actively sending interference information to the eavesdropper.

[0012] According to the active positioning secure communication method based on joint detection provided by the present invention, first, the base station identifies the eavesdropper through the information fed back by the receiving end, and then calculates the coordinate information of the eavesdropper by using the least squares algorithm through the positions of multiple base stations and the radio wave path loss model. By locating the position information of the eavesdropper, targeted defense measures can be implemented. Then, the antenna array of the non-communication base station points the beam to the eavesdropper by adjusting the phase and amplitude of each array element, and actively sends interference information to the eavesdropper, thereby reducing the risk of network attacks, improving the confidentiality of communications, and realizing the secure transmission of smart grid signals. In addition, the active positioning secure communication method of the present invention can be applied to line-of-sight and non-line-of-sight scenarios considering multipath effects, with a wider application scenario, and can provide reliable protection for the wireless communication security of smart grids. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A schematic diagram of the process flow of the active positioning secure communication method based on joint detection provided by the present invention. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0015] An embodiment of the present invention provides an active positioning secure communication method based on joint detection, which is applied to a smart grid system. The smart grid system includes multiple base stations and multiple receiving ends.

[0016] See also Figure 1 , the method includes steps S1 to S5.

[0017] Step S1, multiple base stations communicate with smart meters in the target area to obtain signal characteristics and corresponding coordinate information of the smart meters in the target area. The signal characteristics of the smart meters include the receiving frequency range of the smart meters. When there are multiple receiving ends for signal reception, it is determined whether the receiving frequency range of the receiving end is within the receiving frequency range of the smart meter.

[0018] Among them, the base station will collect the frequency range of smart meters that communicate with each other multiple times during daily communication. The filter at the receiving end records the frequency range of each communication and uploads it to the base station. The base station collects and records this frequency range and the corresponding coordinate information to build a database containing location and signal characteristics. The signal characteristics include the receiving frequency range of the smart meter. When there are multiple receiving ends accessing the communication, due to the different types of devices at the receiving end, the receiving frequency may not be the same as that of the smart meter. Therefore, the base station compares and analyzes the receiving frequency returned by the receiving end with the database to determine whether the receiving end is a smart meter.

[0019] Step S2: If the receiving frequency range of the receiving end is within the receiving frequency range of the smart meter, the receiving end is determined to be a smart meter, and the base station closest to the smart meter is selected to establish a communication connection with the smart meter; if the receiving frequency range of the receiving end is not within the receiving frequency range of the smart meter, the receiving end is marked as an illegal receiver, and step S3 is executed.

[0020] Specifically, if the receiving frequency range of the receiving end is in the database, the receiving end is determined to be a smart meter, and the base station closest to the smart meter is selected to establish a communication connection with the smart meter; if the receiving frequency range of the receiving end is not in the database, the receiving end is marked as an illegal receiver, and step S3 is executed.

[0021] In step S3, the base station transmits the feedforward permission information to the illegal receiver via wireless communication, and determines whether the illegal receiver is an eavesdropper based on the information fed back by the illegal receiver. If the illegal receiver is an eavesdropper, step S4 is executed.

[0022] Wherein, step S3 specifically includes:

[0023] The base station transmits the feedforward permission information to the non-legitimate receiver via wireless communication;

[0024] After receiving the feedforward permission information sent by the base station, the illegal receiver complements the feedforward permission information and sends the feedback information to the base station;

[0025] If the base station can receive the correct feedback information, the illegal receiver is determined to be a smart meter, its receiving frequency is recorded, and the nearest base station is selected to establish a communication connection; if the base station cannot receive the correct feedback information, the illegal receiver is determined to be an eavesdropper.

[0026] In step S4, the eavesdropper establishes a communication connection with the base station. The base station obtains the received signal strength and transmitted signal power of the eavesdropper. According to the radio wave path loss model, the signal is set to satisfy the log-normal shadow model, and the distance from the base station to the eavesdropper is calculated. Then, according to the positions of multiple base stations, the least squares algorithm is used to solve the coordinate information of the eavesdropper.

[0027] Among them, in order to locate the eavesdropper, K base stations jointly establish a communication connection with the eavesdropper. After the eavesdropper receives the signal and establishes a communication link with multiple base stations, K base stations receive the uplink signal returned from the eavesdropper. Each base station measures the strength of the received signal at the same time. First, according to the radio wave path loss model, it is assumed that the signal satisfies the log-normal shadow model, and then the distance from the base station to the eavesdropper is calculated using the following formula:

[0028] ;

[0029] in, d k Indicates k The distance from the base station to the eavesdropper, P t Indicates the transmit signal power of the eavesdropper. When calculating, the unit needs to be converted from watts to dBm; C It represents a constant related to wavelength and antenna gain, and its unit is db; Indicates k When calculating the received signal power corresponding to each base station, the unit needs to be converted from watts to dBm; Indicates k The signal strength random variable caused by shadow fading between the base station and the eavesdropper is a random variable with a mean of 0 and a standard deviation of Gaussian random variable, unit is db; Represents the path loss exponent, which is a dimensionless constant.

[0030] Among them, the following formula is used to solve the eavesdropper's coordinate information:

[0031] ;

[0032] ;

[0033] ;

[0034] in, is the least squares solution, specifically representing the coordinate vector of the eavesdropper; represents the base station coordinate matrix, is the intermediate matrix, represents the coordinates of the first base station, represents the coordinates of the second base station, Indicates k - Coordinates of 1 base station, Indicates k The coordinates of the base stations, d 1 represents the distance from the first base station to the eavesdropper, d k-1 Indicates k -1 distance from the base station to the eavesdropper, T Indicates transpose.

[0035] In step S5, the data processing center shares the eavesdropper's coordinate information to all base stations through the power lines. The antenna array of the non-communication base station points the beam to the eavesdropper by adjusting the phase and amplitude of each array element, thereby actively sending interference information to the eavesdropper. The non-communication base station refers to a base station that has not established a communication connection with the smart meter.

[0036] Among them, the process in which the data processing center shares the eavesdropper's coordinate information to all base stations through the power line satisfies the following formula:

[0037] ;

[0038] in, represents the received signal of the base station, is the Fourier transform of the signal sent by the data processing center, is the frequency domain transfer function of the power line channel, j is an imaginary unit, f Indicates the signal frequency of the signal sent by the data processing center, df Express f integral, t It's time. For noise.

[0039] In this embodiment, the antenna array of the non-communication base station satisfies the following conditional formula:

[0040] ;

[0041] ;

[0042] ;

[0043] in, The first antenna array of the non-communication base station m The phase adjustment of each array element is D represents the array element spacing, Indicates the signal wavelength of the transmission signal of the non-communication base station, is the direction vector of the eavesdropper relative to the non-communication base station, It is the first antenna array of the non-communication base station. m The unit direction vector of the array element, represents the coordinates of the eavesdropper, represents the coordinates of the non-communication base station, Indicates the distance between the non-communicating base station and the eavesdropper.

[0044] The antenna array of the non-communication base station adjusts the phase and amplitude of each array element so that the beam of the antenna array points to the location of the eavesdropper.

[0045] Finally, the smart meter receives the signal and the eavesdropper's received signal The following conditions are met respectively:

[0046] ;

[0047] ;

[0048] in, represents the wireless channel matrix between the base station and the smart meter, represents the wireless channel matrix between the base station and the eavesdropper, Indicates the signal to be transmitted. represents the noise matrix between the base station and the smart meter, represents the noise matrix between the base station and the eavesdropper, Indicates feedforward permission information, Indicates k The wireless channel between the base station and the eavesdropper, K Indicates the total number of base stations, Indicates interference information.

[0049] In summary, according to the active positioning secure communication method based on joint detection provided by the present invention, first the base station identifies the eavesdropper through the information fed back by the receiving end, and then calculates the coordinate information of the eavesdropper using the least squares algorithm through the positions of multiple base stations and the radio wave path loss model. By locating the position information of the eavesdropper, targeted defense measures can be implemented. Then, the antenna array of the non-communication base station points the beam to the eavesdropper by adjusting the phase and amplitude of each array element, and actively sends interference information to the eavesdropper, thereby reducing the risk of network attacks, improving the confidentiality of communications, and realizing the secure transmission of smart grid signals. In addition, the active positioning secure communication method of the present invention can be applied to line-of-sight and non-line-of-sight scenarios considering multipath effects, with a wider application scenario, and can provide reliable protection for the wireless communication security of smart grids.

[0050] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0051] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An active positioning secure communication method based on joint detection, characterized in that: Applied to a smart grid system, the smart grid system comprising a plurality of base stations and a plurality of receiving terminals; The method comprises: Step S1, multiple base stations communicate with smart meters in a target area to obtain signal characteristics and corresponding coordinate information of the smart meters in the target area. The signal characteristics of the smart meters include a receiving frequency range of the smart meters. When multiple receiving ends receive signals, it is determined whether the receiving frequency range of the receiving end is within the receiving frequency range of the smart meters. Step S2: if the receiving frequency range of the receiving end is within the receiving frequency range of the smart meter, the receiving end is determined to be a smart meter, and a base station closest to the smart meter is selected to establish a communication connection with the smart meter; if the receiving frequency range of the receiving end is not within the receiving frequency range of the smart meter, the receiving end is marked as an illegal receiver, and step S3 is executed; Step S3, the base station transmits the feedforward permission information to the illegal receiver via wireless communication, and determines whether the illegal receiver is an eavesdropper based on the information fed back by the illegal receiver. If the illegal receiver is an eavesdropper, step S4 is executed; Step S4, the eavesdropper establishes a communication connection with the base station, the base station obtains the received signal strength and the transmitted signal power of the eavesdropper, and according to the radio wave path loss model, sets the signal to satisfy the log-normal shadow model, calculates the distance from the base station to the eavesdropper, and then uses the least squares algorithm to solve the coordinate information of the eavesdropper according to the positions of multiple base stations; Step S5: The data processing center shares the eavesdropper's coordinate information with all base stations through the power line. The antenna array of the non-communication base station points the beam to the eavesdropper by adjusting the phase and amplitude of each array element, thereby actively sending interference information to the eavesdropper. The non-communication base station refers to a base station that has not established a communication connection with the smart meter. Finally, the received signal of the smart meter and the eavesdropper's received signal The following conditions are met respectively: ； ； in, represents the wireless channel matrix between the base station and the smart meter, represents the wireless channel matrix between the base station and the eavesdropper, Indicates the signal to be transmitted. represents the noise matrix between the base station and the smart meter, represents the noise matrix between the base station and the eavesdropper, Indicates feedforward permission information, Indicates k The wireless channel between the base station and the eavesdropper, K Indicates the total number of base stations, Indicates interference information.

2. The active positioning secure communication method based on joint detection according to claim 1, characterized in that: In step S4, the distance from the base station to the eavesdropper is calculated using the following formula: ； in, d k Indicates k The distance from the base station to the eavesdropper, P t represents the eavesdropper's transmitted signal power, C represents a constant related to wavelength and antenna gain, Indicates k The received signal power corresponding to each base station is Indicates k The signal strength random variable between the base station and the eavesdropper due to shadow fading, Represents the path loss exponent.

3. The active positioning secure communication method based on joint detection according to claim 2, characterized in that: In step S4, the coordinate information of the eavesdropper is solved using the following formula: ； ； ； in, represents the coordinate vector of the eavesdropper, represents the base station coordinate matrix, is the intermediate matrix, represents the coordinates of the first base station, represents the coordinates of the second base station, Indicates k - Coordinates of 1 base station, Indicates k The coordinates of the base stations, d 1 represents the distance from the first base station to the eavesdropper, d k-1 Indicates k -1 distance from the base station to the eavesdropper, T Indicates transpose.

4. The active positioning secure communication method based on joint detection according to claim 3 is characterized in that: In step S5, the data processing center shares the eavesdropper's coordinate information to all base stations through the power line, satisfying the following formula: ； in, represents the received signal of the base station, is the Fourier transform of the signal sent by the data processing center, is the frequency domain transfer function of the power line channel, j is an imaginary unit, f Indicates the signal frequency of the signal sent by the data processing center, df Express f integral, t It's time. For noise.

5. The active positioning secure communication method based on joint detection according to claim 4 is characterized in that: In step S5, the antenna array of the non-communication base station satisfies the following conditional formula: ； ； ； in, The first antenna array of the non-communication base station m The phase adjustment of each array element is D represents the array element spacing, Indicates the signal wavelength of the transmission signal of the non-communication base station, is the direction vector of the eavesdropper relative to the non-communication base station, It is the first antenna array of the non-communication base station. m The unit direction vector of the array element, represents the coordinates of the eavesdropper, represents the coordinates of the non-communication base station, Indicates the distance between the non-communicating base station and the eavesdropper.

6. The active positioning secure communication method based on joint detection according to claim 1, characterized in that: Step S3 specifically includes: The base station transmits the feedforward permission information to the non-legal receiver via wireless communication; After receiving the feedforward permission information sent by the base station, the illegal receiver complements the feedforward permission information and sends the feedback information to the base station; If the base station can receive the correct feedback information, the illegal receiver is determined to be a smart meter, its receiving frequency is recorded, and the nearest base station is selected to establish a communication connection; if the base station cannot receive the correct feedback information, the illegal receiver is determined to be an eavesdropper.

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