A multi-carrier array antenna transmitter design method, device and storage medium

Abstract

This application discloses a multi-carrier array antenna transmitter design method, device, and storage medium, relating to the field of wireless communication technology. This method addresses the existing problem of inability to achieve secure and reliable communication in large-scale, complex, multi-user environments. The method includes: constructing a large-scale multicast group system, establishing a spatial coordinate system to determine the positional relationship between the transmitter and the desired user, and obtaining a transmit array steering matrix; constructing a multi-carrier array transmitter, and designing the antenna module, radio frequency module, digital phase shift module, and baseband signal processing module within the transmitter; proposing a layered transmission method, hierarchically designing, optimizing, and solving the transmitter array weighting vector; and utilizing artificial noise scrambling technology to design a baseband signal processing module and calculate an artificial noise projection matrix to maximize the disruption to eavesdroppers. The multi-carrier array antenna transmitter achieves the expansion of the multicast system without increasing the number of transmitting antennas, ensuring secure and reliable communication for more desired users.

Description

Technical Field

[0001] The present application relates to the field of wireless communication technology, and in particular to a multi-carrier array antenna transmitter design method, device and storage medium. Background Art

[0002] While wireless communications bring convenience to human development, the risk of information leakage is also increasing, and information security is gaining increasing attention. With the proliferation of mobile devices and the emergence of supercomputers, relying solely on high-level encryption technologies is no longer sufficient to ensure information confidentiality. Security issues such as confidentiality leaks and cyberattacks continue to emerge in wireless communications. Ensuring information security in wireless communications faces increasing challenges. Physical layer security technology, as an effective complementary technology to traditional encryption security mechanisms, provides a secure barrier to information transmission. Array antennas offer a new approach to addressing these issues.

[0003] Array antenna physical layer multicast is an effective way to improve wireless network distribution efficiency. It leverages the broadcast nature of wireless channels to simultaneously send information to multiple desired users belonging to the same multicast group. The main challenge with secure communication in large-scale multicast groups is the large number of desired users, who are widely dispersed across space. Existing wireless communication technologies cannot achieve secure communication among multiple users in the same direction but at different distances. Summary of the Invention

[0004] The embodiments of the present application provide a multi-carrier array antenna transmitter design method, device, and storage medium to solve the problem in the prior art that multiple users cannot achieve secure communication in the same direction but at different distances. This achieves the goal of expanding the scale of the multicast system without increasing the number of transmitting antennas, ensuring secure communication for more desired users, and being able to distinguish multicast users with the same direction angle but different distances, effectively receiving their respective signals without interfering with each other.

[0005] In a first aspect, an embodiment of the present invention provides a multi-carrier array antenna transmitter design method, the method comprising:

[0006] Constructing a large-scale multicast group system and establishing a coordinate system, determining a transmitter array structure and establishing a coordinate system to determine a positional relationship between the transmitter array and a desired user;

[0007] Designing an antenna module and a radio frequency module of the transmitter array, and defining subcarriers of the same order in each antenna in the transmitter array as a layer;

[0008] Obtaining a multi-carrier transmission array steering vector according to a relative position relationship between the multicast user and the transmitter array;

[0009] hierarchically designing the transmitter array weight vector, optimizing and solving the transmitter array weight vector;

[0010] The signal is transmitted according to the transmitter array weight vector and the artificial noise matrix.

[0011] With reference to the first aspect, in a possible implementation, defining subcarriers of the same order in each antenna in the transmitter array as a layer includes: the subcarriers are represented as:

[0012] f k,n =f k,c +Δf k,n ,k=1,2,…,K,n=1,2,…,N,

[0013] Among them, f k,c is the carrier frequency of the kth layer, Δf k,n is the frequency difference between different antenna elements in the kth layer, N represents the number of antennas, and K represents the number of subcarriers per antenna.

[0014] With reference to the first aspect, in one possible implementation, obtaining a multi-carrier transmit array steering vector includes:

[0015] Obtaining the energy of the transmitted signal from the kth layer received by the far-field target, and determining the array steering vector of the kth layer;

[0016] The energy of the transmission signals of all layers at the far-field target is determined according to the array steering vector of the kth layer, and then the multi-carrier transmission array steering vector is calculated.

[0017] With reference to the first aspect, in a possible implementation, the hierarchical design of the transmitter array weight vector and the optimization of the transmitter array weight vector include the following two constraints:

[0018] The multicast users in a specific multicast group in the multicast group system can receive signals without causing interference to the multicast users in other multicast groups;

[0019] The receiving power of the multicast user is the smallest.

[0020] In combination with the first aspect, in a possible implementation, solving the transmitter array weight vector includes: maximizing the transmission power of the noise by a method of minimum modulation symbol transmission power, while ensuring that the multicast user can receive the transmission signal.

[0021] In conjunction with the first aspect, in a possible implementation, the artificial noise matrix calculation method is: in represents the steering vector matrix of all multicast groups; H L,k (t) denotes the joint steering vector matrix of the desired users in multicast group k; tr{·} denotes the trace of the matrix; T represents the transposed conjugate matrix of the steering vector of the multicast group in the multicast system; AN (t) represents the artificial noise matrix; t represents the current time;

[0022] The steering vector of the multicast group in Indicates the number of expected users in the multicast group in the multicast system;

[0023] According to the null space mapping criterion, when NK>L T When , the artificial noise matrix is calculated as Wherein, N represents the number of antennas in the transmitter array; K represents the number of subcarriers per transmitting antenna; I NK Represents the identity matrix.

[0024] In a second aspect, an embodiment of the present invention provides a multi-carrier array antenna transmitter design device, the device comprising:

[0025] An array antenna module is used to construct a large-scale multicast group system and establish a coordinate system, determine the transmitter array structure and establish a coordinate system to determine the position relationship between the transmitter array and the desired user;

[0026] A radio frequency module, configured to design an antenna module and a radio frequency module of the transmitter array, and define subcarriers of the same order in each antenna in the transmitter array as a layer;

[0027] A weighted vector acquisition module, configured to acquire a multi-carrier transmission array steering vector based on a relative position relationship between a multicast user and the transmitter array;

[0028] A digital phase shifter module, configured to hierarchically design the transmitter array weight vector, and optimize and solve the transmitter array weight vector;

[0029] The baseband signal processing module is used to send the signal according to the transmitter array weight vector and the artificial noise matrix.

[0030] With reference to the second aspect, in a possible implementation, the radio frequency module includes: the subcarrier is represented as:

[0031] f k,n =f k,c +Δf k,n ,k=1,2,…,K,n=1,2,…,N,

[0032] Among them, f k,c is the carrier frequency of the kth layer, Δf k,n is the frequency difference between different antenna elements in the kth layer, N represents the number of antennas, and K represents the number of subcarriers per antenna.

[0033] With reference to the second aspect, in one possible implementation, the radio frequency module includes:

[0034] Obtaining the energy of the transmitted signal from the kth layer received by the far-field target, and determining the array steering vector of the kth layer;

[0035] The energy of the transmission signals of all layers at the far-field target is determined according to the array steering vector of the kth layer, and then the multi-carrier transmission array steering vector is calculated.

[0036] In conjunction with the second aspect, in a possible implementation, the digital phase shifter module further includes the following two constraints:

[0037] The multicast users in a specific multicast group in the multicast group system can receive signals without causing interference to the multicast users in other multicast groups;

[0038] The receiving power of the multicast user is the smallest.

[0039] In conjunction with the second aspect, in a possible implementation, the digital phase shifter module includes a method of maximizing the transmission power of noise through minimum modulation symbol transmission power while ensuring that the multicast user can receive the transmission signal.

[0040] In conjunction with the second aspect, in a possible implementation, the baseband signal processing module is configured to: in represents the steering vector matrix of all multicast groups; H L,k (t) denotes the joint steering vector matrix of the desired users in multicast group k; tr{·} denotes the trace of the matrix; T represents the transposed conjugate matrix of the steering vector of the multicast group in the multicast system; AN (t) represents the artificial noise matrix; t represents the current time;

[0041] The steering vector of the multicast group in Indicates the number of expected users in the multicast group in the multicast system;

[0042] According to the null space mapping criterion, when NK>L T When , the artificial noise matrix is calculated as Wherein, N represents the number of antennas in the transmitter array; represents the number of subcarriers per transmitting antenna; I NK Represents the identity matrix.

[0043] In a third aspect, an embodiment of the present invention provides a multi-carrier array antenna transmitter design server, including a memory and a processor;

[0044] The memory is used to store computer-executable instructions;

[0045] The processor is configured to execute the computer-executable instructions to implement the first aspect or the method described in any one of the first aspects.

[0046] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores executable instructions, and when a computer executes the executable instructions, it can implement the method described in the first aspect or any one of the first aspects.

[0047] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0048] The embodiment of the present invention adopts a multi-carrier array antenna transmitter design method, device and storage medium. The method includes: constructing a large-scale multicast group system and establishing a coordinate system, determining the transmitter array structure and establishing the coordinate system to determine the positional relationship between the transmitter array and the desired user; designing the antenna module and radio frequency module of the transmitter array, defining subcarriers of the same order in each antenna in the transmitter array as a layer; obtaining a multi-carrier transmission array steering vector based on the relative positional relationship between the multicast user and the transmitter array; hierarchically designing the transmitter array weighting vector, optimizing and solving the transmitter array weighting vector; and transmitting a signal based on the transmitter array weighting vector and an artificial noise matrix. In this method, the establishment of a coordinate system is conducive to the subsequent analysis of the multicast array antenna transmitter. The stratification can ensure that the expected users in the multicast group receive the signal normally while not interfering with the expected users of other multicast groups. Under the constraint that all expected users can reliably receive the signal, the transmitting antenna array is designed with the minimum transmitting signal power, which effectively solves the problem of reasonable allocation of the existing transmitting signal power and the artificial noise power. In addition, the scale of the multicast system is expanded without increasing the number of transmitting antennas, ensuring the secure communication of the expected users and being able to distinguish multicast users with the same direction angle but different distances. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments of the present invention or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0050] Figure 1 A flowchart of the steps of the multi-carrier array antenna transmitter design method provided in an embodiment of the present application;

[0051] Figure 2 A schematic diagram of a large-scale multicast group provided in an embodiment of the present application;

[0052] Figure 3 A schematic diagram of the structure of a multi-carrier frequency-controlled array transmitter provided in an embodiment of the present application;

[0053] Figure 4A A three-dimensional spatial simulation diagram of the artificial noise interference power distribution provided in an embodiment of the present application;

[0054] Figure 4B An angular cross-sectional simulation diagram of the artificial noise interference power distribution provided in an embodiment of the present application;

[0055] Figure 4C A simulation diagram of the distance-dimensional cross-section of the artificial noise interference power distribution provided in an embodiment of the present application;

[0056] Figure 5A L provided in the embodiment of this application T =9 Three-dimensional spatial simulation diagram of the power distribution of multi-angle artificial noise interference;

[0057] Figure 5B L provided in the embodiment of this application T =9 Angle-dimensional cross-sectional simulation diagram of the power distribution of multi-angle artificial noise interference;

[0058] Figure 5C L provided in the embodiment of this application T =9Distance dimension cross-section simulation diagram of multi-angle artificial noise interference power distribution;

[0059] Figure 6A A three-dimensional simulation diagram of the receiving SINR space of multicast group 1 provided in an embodiment of the present application;

[0060] Figure 6B This is a simulated cross-sectional diagram of the SINR angle of multicast group 1 received according to an embodiment of the present application;

[0061] Figure 6C This is a simulation diagram of the SINR distance dimension profile of multicast group 1 received according to an embodiment of the present application;

[0062] Figure 7A A three-dimensional simulation diagram of the receiving SINR space of multicast group 2 provided in an embodiment of the present application;

[0063] Figure 7B This is a simulated cross-sectional diagram of the SINR angle of multicast group 2 received according to an embodiment of the present application;

[0064] Figure 7C This is a simulation diagram of the SINR distance dimension profile of multicast group 2 received in an embodiment of the present application;

[0065] Figure 8 A schematic diagram showing the relationship between the system security capacity and the expected number of multicast users of the multi-carrier secure communication solution provided in an embodiment of the present application;

[0066] Figure 9 Schematic diagram of a multi-carrier array antenna transmitter design device provided in an embodiment of the present application;

[0067] Figure 10 Schematic diagram of a multi-carrier array antenna transmitter design server provided in an embodiment of the present application. DETAILED DESCRIPTION

[0068] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0069] While wireless communications bring immense convenience to human development, they also pose increasingly serious information security threats. The proliferation of mobile devices and the emergence of supercomputers have led to a surge in security issues such as confidentiality leaks and cyberattacks in wireless communications that rely solely on high-level encryption technologies. Wireless communication security faces increasing challenges. Physical layer security, as an effective complement to traditional encryption security mechanisms, provides a secure barrier for information transmission. Array antennas offer a new approach to addressing these issues. Their key strengths lie in their ability to suppress the effects of other signals while enhancing the desired signal, making them compatible with various wireless communication technologies. Array antenna transmission, leveraging spatial degrees of freedom and antenna gain, has been recognized as a powerful driver of secure and reliable modern communications. Therefore, research on array antenna transmitters holds significant scientific and practical value.

[0070] Physical layer multicast is an effective way to improve the efficiency of content distribution in wireless networks. It leverages the broadcast nature of wireless channels to simultaneously send information to multiple desired users belonging to the same multicast group. It holds great potential in many emerging scenarios, such as the Internet of Vehicles (IoV), the Internet of Things (IoT), drone group control, and mobile TV. The main challenge with secure communication in large-scale multicast groups is the large number of desired users and their wide spatial dispersion. Traditional single-carrier array antenna transmission technology cannot achieve secure communication between users in the same direction but at different distances. Currently, research on secure physical layer transmission focuses primarily on single-authorized user communication systems or multi-authorized user broadcast communication systems, with limited research on more complex multicast group communication systems. To support the "Internet of Everything, Intelligent Connection of Everything" vision of fifth- and sixth-generation mobile communications, research on secure wireless physical layer transmission technologies for large-scale multicast users is of great significance. A prior art approach has also proposed a secure transmission method based on artificial noise-assisted random subcarrier directional modulation. This method involves first randomly selecting subcarriers, then performing phase-aligned beamforming for confidential information and null-space projection of artificial noise, and finally verifying that this method achieves secure and accurate information transmission in wireless line-of-sight transmission. The drawback of this method is that it only addresses secure transmission for a single target user and fails to consider multi-target, multi-beam secure transmission strategies. Furthermore, the desired user's single antenna reception cannot effectively eliminate interfering signals. Therefore, secure transmission cannot be guaranteed in complex electromagnetic environments with multiple users.

[0071] Based on this, an embodiment of the present invention provides a multi-carrier array antenna transmitter design method, such as Figure 1 The method shown includes the following steps S101 to S105.

[0072] S101, constructing a large-scale multicast group system and establishing a coordinate system, determining a transmitter array structure and establishing a coordinate system to determine a positional relationship between the transmitter array and a desired user.

[0073] S102: Design the antenna module and radio frequency module of the transmitter array, and define subcarriers with the same order in each antenna in the transmitter array as a layer.

[0074] S103: Obtain a multi-carrier transmission array steering vector according to the relative position relationship between the multicast user and the transmitter array.

[0075] S104, hierarchically designing transmitter array weight vectors, optimizing and solving the transmitter array weight vectors.

[0076] S105 , sending the signal according to the transmitter array weight vector and the artificial noise matrix.

[0077] In this application, the array antenna module, radio frequency module, digital phase shifter module and baseband signal processing module in the transmitter are designed in sequence. A multi-carrier frequency-controlled array antenna transmitter structure is adopted, and multi-carrier frequency, artificial noise assistance, and array weight vector optimization are used to ensure safe and reliable transmission in a large-scale complex electromagnetic eavesdropping environment. Due to the limitation of transmitter hardware, that is, the number of transmitter array antennas in a large-scale wireless communication environment is less than the number of expected users, the antenna module and radio frequency module are designed, and a layered transmission method is proposed. Since the eavesdropper's information is unknown, the digital phase shifter module is designed using the criterion of minimizing the transmitted information power, and the array weight vector is optimized to minimize the possibility of information being intercepted, while meeting the received signal power constraint of the expected user and ensuring effective reception by the expected user. Then, the baseband signal processing module is designed, artificial noise is introduced into the baseband signal, and the remaining total transmission power is allocated to the artificial noise to maximize the disruption of the eavesdropper's received signal.

[0078] In step S101, a large-scale multicast group is constructed, taking into account the basic multicast system, such as Figure 2 As shown in Figure 1, it contains an array antenna transmitter and K multicast groups. There are one or more passive eavesdroppers around each multicast group. The desired users in the same multicast group receive the same multicast information, and the desired users in the same multicast group can be dispersed in space. The Kth multicast group contains G K The platform expects users.

[0079] The transmitter structure of multi-carrier frequency-controlled array, such as Figure 3 As shown. The transmitter antenna array consists of N antennas distributed linearly. The number of subcarriers for each antenna is K, and the distance between adjacent antennas is d. The position of the first transmitting antenna is determined as the origin of the system coordinates. To facilitate analysis, this application proposes a layered transmission method for the transmitter, defining the subcarriers of the same order in each antenna as a layer. The transmitter is required to send multiple different information streams to the corresponding multicast group at the same time. The first antenna of the transmitter is set as the reference array element. Considering the target far-field signal transmission model, parallel wave and line-of-sight transmission can be established at the same time.

[0080] In step S102, the subcarriers with the same order in each antenna in the transmitter array are defined as a layer, such as Figure 3 As shown, the transmitting antennas are layered, including: setting the subcarriers with the same order in each transmitting antenna to a layer, and the subcarriers are represented as: f k,n =f k,c +Δf k,n ; k=1,2,…,K,n=1,2,…,N, where f k,c is the carrier frequency of the kth layer, Δf k,n is the frequency difference between different antenna elements in the kth layer, N is the number of antennas, and K is the number of subcarriers per antenna.

[0081] In step S103, a multi-carrier transmission array steering vector is obtained according to the position information of the multicast user relative to the transmitter, including:

[0082] The energy of the transmitted signal from the kth layer received by the far-field target (r, θ) is expressed as,

[0083] Then for the far-field target (r,θ), the k-th layer array steering vector is written as:

[0084]

[0085] Based on the array steering vector of the kth layer, the energy of the transmitted signals of all layers at the far-field target is determined, and then the multi-carrier transmit array steering vector is calculated. The multi-carrier transmit array steering vector is: j represents the imaginary unit.

[0086] In step S104, the transmitter array weight vector is designed hierarchically, and the transmitter array weight vector is optimized and solved, including the following two constraints:

[0087] Constraint 1: In a multicast group system, multicast users in a specific multicast group can receive signals without causing interference to multicast users in other multicast groups.

[0088] Constraint 2: The receiving power of multicast users is minimized.

[0089] The number of available carriers for each transmitting antenna is K, that is, the system is divided into K layers of transmission. First, the expected users who receive the same information are divided into the same multicast group, and the number of expected users in the multicast group is less than the number of transmitting antennas. Second, the transmitter transmits confidential information in layers, and the kth layer transmits the modulation symbol x k (t), corresponding to all desired users in multicast group k. Hierarchical design array weight vector w k , ensuring that the desired users in multicast group k receive the signal normally, while not interfering with users in other multicast groups.

[0090] Reference Figure 3 , the transmitted signal vector at time t is s(t)=[s1(t),s2(t),…,s N (t)], expressed as

[0091]

[0092] The location of the gth desired user in the multicast group k layer is The steering vector of the desired user is Then, the joint steering matrix of the desired users in multicast group k is expressed as

[0093]

[0094] The k-th layer steering matrix of the desired user in multicast group k is

[0095]

[0096] The received signal vector of multicast group k is:

[0097]

[0098] in, represents the additive white Gaussian noise matrix of multicast group k.

[0099] Optimize the k-th layer array weight vector w k The design principle is to ensure that the desired users in the k-th layer of the multicast group receive signals normally while not interfering with the desired users in other multicast groups. There are one or more eavesdroppers around or inside each multicast group who steal information. In actual wireless communication, it is often impossible to obtain the eavesdropper's information. In this case, artificial noise is mainly used to interfere with the eavesdropper, making it unable to demodulate the confidential information normally. While ensuring that the desired users receive signals normally, the artificial noise transmission power is maximized. The weight vector w of the k-th layer array is k The optimization problem is:

[0100]

[0101] in, represents the k-th layer steering matrix of the remaining multicast groups other than multicast group k; ξ k,g represents the minimum expected received power of the desired user in multicast group k; represents the number of remaining desired users outside of multicast group k. Constraint 1 states that all users in multicast group k receive the signal transmitted at layer k and meet the minimum receive power requirement. Constraint 2 states that users outside of multicast group k cannot receive the signal transmitted at layer k.

[0102] In step S104, the transmitter array weight vector is solved, including: maximizing the noise transmission power by a method of minimum modulation symbol transmission power, while ensuring that multicast users can receive the transmission signal.

[0103] The total system transmit power is Among them, P L,k represents the transmission signal power of the kth layer. By minimizing the transmission power of the modulation symbol, the transmission power of the artificial noise is maximized. At the same time, in order to ensure reliable reception for each user, the optimization problem is rewritten as:

[0104]

[0105] To solve this optimization problem, the matrix Perform singular value decomposition and get:

[0106]

[0107] According to the singular value decomposition theorem, we get in i=1,2,…,N(K-1)-L -k Assumptions and Converts to:

[0108]

[0109] According to the Lagrange multiplier method, the optimal array weight vector of the kth layer is obtained

[0110]

[0111] In step S105, the artificial noise matrix is calculated as follows: Among them H L (t) represents the steering vector matrix of all multicast groups, tr represents the matrix symbol; T represents the transposed conjugate matrix of the steering vector of the multicast group in the multicast system; AN (t) represents the artificial noise matrix; t represents the current time; the steering vector of the multicast group in represents the number of expected users in the multicast group in the multicast system; according to the null space mapping criterion, when NK>L T When , the artificial noise matrix is calculated as Where N is the number of antennas in the transmitter array; K is the number of subcarriers per transmitting antenna; I NK Represents the identity matrix.

[0112] Based on the transmit array weight vector and artificial noise obtained in the above steps, the transmit signal and artificial noise are sent out through the antenna module, thus completing the transmission work. The multicast user recovers the code element information at the receiving end.

[0113] This application provides a specific embodiment to illustrate the method described in this application.

[0114] The parameters set in the simulation are as follows: the number of frequency-controlled array antennas N = 8. The carrier frequency of the first layer of the antenna array is f 1,c =1GHz, the carrier frequency of the second layer is f 2,c=2GHz. The minimum safe receiving power of all desired multicast users is -90dBm. In the multicast system, the number of multicast groups K = 2, and the number of desired users in each multicast group is G1 = 3, G2 = 3. The desired user position of multicast group 1 (r 1,1 ,θ 1,1 )=(1200m,30°),(r 1,2 ,θ 1,2 )=(1400m,40°),(r 1,3 ,θ 1,3 )=(1600m,35°). The expected user location of multicast group 2 (r 2,1 ,θ 2,1 )=(3200m,40°),(r 2,2 ,θ 2,2 )=(3400m,60°),(r 2,3 ,θ 2,3 )=(3600m,50°).

[0115] Figures 4A to 4C The multi-dimensional artificial noise interference power distribution is simulated. Figure 4A It is a three-dimensional diagram of space. Figure 4B is the angle-dimensional cross-section, Figure 4C is a distance dimension profile. As can be seen from the figure, the artificial noise interference power forms a null at the multicast user location and is evenly distributed at the rest of the space. This shows that when the number of multicast users is less than the number of transmitting antennas, both the single-carrier secure communication scheme and the multi-carrier secure communication scheme can achieve artificial noise without affecting the multicast users while interfering with the eavesdropper by designing the artificial noise matrix. When the number of multicast users is L T =9, the multi-angle artificial noise interference power distribution of the multi-carrier secure communication scheme is as follows Figures 5A to 5C As shown, Figure 5A For L T =9 three-dimensional space diagram, Figure 5B For L T =9 angle cross-section, Figure 5C For L T =9 range-dimensional profile. As shown in the figure, the artificial noise interference power forms nulls at all multicast user locations. This demonstrates that artificial noise technology based on a multicarrier frequency-steering array can ensure secure communication for more desired users without adding additional transmit antennas.

[0116] Analyze the received signal to interference plus noise ratio (SINR) distribution of the multicast group. Figures 6A to 6C This is the distribution diagram of the received SINR for multicast group 1. 7A to 7Cis the distribution diagram of the received SINR corresponding to multicast group 2. Figure 6A is the spatial three-dimensional graph of multicast group 1, Figure 6B This is an angled cross-sectional view of multicast group 1. Figure 6C is the distance dimension profile of multicast group 1, Figure 7A is the spatial three-dimensional graph of multicast group 2, Figure 7B This is an angled cross-sectional view of multicast group 2. Figure 7C This is the distance dimension profile of multicast group 2. Analysis Figures 6A to 6C , it is found that the SINR peak appears at the desired user position of multicast group 1, and is the smallest at the desired user position of multicast group 2. In addition, the SINR is also very small at other positions. A similar situation to that of multicast group 1 can be obtained, indicating that after the optimization of the proposed scheme, the multicast group effectively receives the corresponding confidential signal, other multicast groups cannot receive non-self-signals, and eavesdroppers cannot steal any confidential information. At the same time, compared with the traditional phased array multicast group security communication scheme, the scheme proposed in this section realizes the secure communication of users with different distances in the same direction, and can distinguish multicast users with the same direction angle but different distances, that is, the desired user (r 1,2 ,θ 1,2 )=(1400m,40°) and the expected user (r 2,1 ,θ 2,1 )=(3200m,40°) effectively receive their respective signals without interfering with each other.

[0117] like Figure 8 The figure shows an analysis of the relationship between the system security capacity of the proposed multi-carrier security communication scheme and the number of expected multicast users, and is compared with a single-carrier security communication scheme. As can be seen from the figure, when the number of expected multicast users is small, both the traditional single-carrier security communication scheme and the scheme proposed in this chapter can provide good security communication. It is worth noting that at this time, the average security capacity of the proposed scheme is better than that of the single-carrier security communication scheme. This is mainly because the proposed scheme has a higher degree of freedom to optimize the transmission scheme and proposes an optimization method to maximize the artificial noise transmission power in the transmission scheme. When the number of expected multicast users increases, the security performance of the traditional single-carrier multicast group communication scheme gradually declines, and the difference in average security capacity rapidly expands.

[0118] The embodiment of the present invention provides a multi-carrier array antenna transmitter design device such as Figure 9 As shown, the device includes: an array antenna module 901, a radio frequency module 902, a weighted vector acquisition module 903, a digital phase shifter module 904 and a baseband signal processing module 905.

[0119] The array antenna module 901 is used to construct a large-scale multicast group system and establish a coordinate system, determine the transmitter array structure and establish a coordinate system to determine the position relationship between the transmitter array and the desired user.

[0120] The RF module 902 is used to design the antenna module and RF module of the transmitter array, and defines the subcarriers with the same order in each antenna in the transmitter array as a layer. The RF module 902 includes subcarriers represented as: k,n =f k,c +Δf k,n ; k=1,2,…,K,n=1,2,…,N, where f k,c is the carrier frequency of the kth layer, Δf k,n is the frequency difference between different antenna elements in the kth layer. RF module 902 includes the following steps: obtaining the energy of the transmitted signal from the kth layer received by the far-field target and determining the array steering vector of the kth layer; determining the energy of the transmitted signals of all layers at the far-field target based on the array steering vector of the kth layer, and then calculating the multi-carrier transmit array steering vector.

[0121] The weighted vector acquisition module 903 is configured to acquire a multi-carrier transmission array steering vector according to the relative position relationship between the multicast user and the transmitter array.

[0122] The digital phase shifter module 904 is used to hierarchically design, optimize, and solve the transmitter array weight vector. The digital phase shifter module 904 includes a method for maximizing the transmit power of noise by minimizing the modulation symbol transmit power while ensuring that multicast users can receive the transmitted signal.

[0123] The baseband signal processing module 905 is used to send the signal according to the transmitter array weight vector and the artificial noise matrix. in represents the steering vector matrix of all multicast groups; H L,k (t) denotes the joint steering vector matrix of the desired users in multicast group k; tr{·} denotes the trace of the matrix; T represents the transposed conjugate matrix of the steering vector of the multicast group in the multicast system; AN (t) represents the artificial noise matrix; t represents the current time; the steering vector of the multicast group in represents the number of expected users in the multicast group in the multicast system; according to the null space mapping criterion, when NK>L T When , the artificial noise matrix is calculated as Where N is the number of antennas in the transmitter array; K is the number of subcarriers per transmitting antenna; I NK Represents the identity matrix.

[0124] The embodiment of the present invention provides a multi-carrier array antenna transmitter design server, such as Figure 10The system shown includes a memory 1001 and a processor 1002 ; the memory 1001 is used to store computer-executable instructions; the processor 1002 is used to execute the computer-executable instructions to implement the above method.

[0125] An embodiment of the present invention provides a computer-readable storage medium, which stores executable instructions. When a computer executes the executable instructions, the above method can be implemented.

[0126] The above-mentioned storage medium includes, but is not limited to, random access memory (RAM), read-only memory (ROM), cache, hard disk drive (HDD), or memory card. The memory can be used to store computer program instructions.

[0127] The methods, devices, or modules described in this application can be implemented in the form of computer-readable program code. The controller can be implemented in any appropriate manner. For example, the controller can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program code (such as software or firmware) that can be executed by the (micro)processor, logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers. Examples of controllers include, but are not limited to, the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicone Labs C9051F320. The memory controller can also be implemented as part of the control logic of the memory. Those skilled in the art will also know that in addition to implementing the controller in the form of pure computer-readable program code, it is entirely possible to implement the same function of the controller in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, such a controller can be considered a hardware component, and the devices included therein for implementing various functions can also be considered as structures within the hardware component. Or even, the means for implementing various functions may be considered to be both a software module for implementing the method and a structure within a hardware component.

[0128] It can be seen from the description of the above implementation methods that those skilled in the art can clearly understand that the present application can be implemented by means of software plus necessary hardware. Based on this understanding, the technical solution of the present application can essentially or the part that contributes to the prior art can be embodied in the form of a software product, or it can be embodied through the implementation process of data migration. The computer software product can be stored in a storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a mobile terminal, a server, or a network device, etc.) to execute the methods described in the various embodiments of the present application or certain parts of the embodiments.

[0129] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A multi-carrier array antenna transmitter design method, characterized in that: include: Constructing a large-scale multicast group system and establishing a coordinate system, determining a transmitter array structure and establishing a coordinate system to determine a positional relationship between the transmitter array and a desired user; Designing an antenna module and a radio frequency module of the transmitter array, and defining subcarriers of the same order in each antenna in the transmitter array as a layer; Obtaining a multi-carrier transmission array steering vector according to a relative positional relationship between the multicast user and the transmitter array includes: obtaining the energy of the transmission signal from the kth layer received by the far-field target (r, θ) as: For the far-field target (r,θ), the array steering vector of the kth layer is: Based on the array steering vector of the kth layer, the energy of the transmitted signals of all layers at the far-field target is determined, and then the multi-carrier transmit array steering vector is calculated. The multi-carrier transmit array steering vector is: Where y k (r,θ) is the transmitted signal energy of the kth layer, (r,θ) represents the far-field target, f k,n is the subcarrier of different antenna arrays in the kth layer, N represents the number of antennas, n represents the nth antenna, f k,c is the carrier frequency of the kth layer, Δf k,n is the frequency difference between different antenna elements in the kth layer, h L,k represents the array steering vector of the kth layer, and T represents the transposed matrix; The transmitter array weight vector is designed hierarchically, and the transmitter array weight vector is optimized and solved, including the following two constraints: Constraint 1: Multicast users in a specific multicast group in the multicast group system can receive the signal without interfering with multicast users in the remaining multicast groups. Constraint 2: The receiving power of multicast users is minimized; Optimize the k-th layer array weight vector w k The design principle is to ensure that the desired users in the k-th layer of the multicast group receive signals normally while not interfering with the desired users in other multicast groups. There are one or more eavesdroppers around or inside each multicast group to steal information. Under the condition that the desired users receive signals normally, the artificial noise transmission power is maximized. The weight vector w of the k-th layer array is k The optimization problem is: in, represents the k-th layer steering matrix of the remaining multicast groups other than multicast group k; ξ k,g represents the minimum expected received power of the desired user in multicast group k; represents the number of remaining desired users outside multicast group k, P AN Indicates the artificial noise emission power; The method includes transmitting a signal according to the transmitter array weight vector and the artificial noise matrix, comprising: The calculation method of artificial noise matrix is: Among them, H L (t) represents the steering vector matrix of all multicast groups, tr represents the matrix symbol; T represents the transposed conjugate matrix of the steering vector of the multicast group in the multicast group system; AN (t) represents the artificial noise matrix; t represents the current time; Steering vector for a multicast group in, Indicates the number of expected users in the multicast group in the multicast group system; According to the null space mapping criterion, when NK>L T When , the artificial noise matrix is obtained as: Where N is the number of antennas in the transmitter array; K is the number of subcarriers per transmitting antenna; I NK represents the identity matrix; Based on the transmitter array weight vector and artificial noise, the transmission signal and artificial noise are sent out through the antenna module, thus completing the transmission work.

2. The method according to claim 1, characterized in that The defining subcarriers of the same order in each antenna in the transmitter array as a layer includes: the subcarriers are represented as: f k,n =f k,c +Δf k,n ;k=1,2,…,K,n=1,2,…,N, Among them, f k,c is the carrier frequency of the kth layer, Δf k,n is the frequency difference between different antenna elements in the kth layer, N represents the number of antennas, and K represents the number of subcarriers per antenna.

3. A multi-carrier array antenna transmitter design device, characterized in that: include: An array antenna module is used to construct a large-scale multicast group system and establish a coordinate system, determine the transmitter array structure and establish a coordinate system to determine the position relationship between the transmitter array and the desired user; A radio frequency module, configured to design an antenna module and a radio frequency module of the transmitter array, and define subcarriers of the same order in each antenna in the transmitter array as a layer; The weighted vector acquisition module is used to obtain the multi-carrier transmission array steering vector based on the relative position relationship between the multicast user and the transmitter array, including: obtaining the transmission signal energy from the kth layer received by the far-field target (r, θ) expressed as: For the far-field target (r,θ), the array steering vector of the kth layer is: Based on the array steering vector of the kth layer, the energy of the transmitted signals of all layers at the far-field target is determined, and then the multi-carrier transmit array steering vector is calculated. The multi-carrier transmit array steering vector is: Where y k (r,θ) is the transmitted signal energy of the kth layer, (r,θ) represents the far-field target, f k,n is the subcarrier of different antenna arrays in the kth layer, N represents the number of antennas, n represents the nth antenna, f k,c is the carrier frequency of the kth layer, Δf k,n is the frequency difference between different antenna elements in the kth layer, h L,k represents the array steering vector of the kth layer, and T represents the transposed matrix; The digital phase shifter module is used to hierarchically design the transmitter array weight vector, optimize and solve the transmitter array weight vector, including the following two constraints: Constraint 1: Multicast users in a specific multicast group in the multicast group system can receive the signal without interfering with multicast users in the remaining multicast groups. Constraint 2: The receiving power of multicast users is minimized; Optimize the k-th layer array weight vector w k The design principle is to ensure that the desired users in the k-th layer of the multicast group receive signals normally while not interfering with the desired users in other multicast groups. There are one or more eavesdroppers around or inside each multicast group to steal information. Under the condition that the desired users receive signals normally, the artificial noise transmission power is maximized. The weight vector w of the k-th layer array is k The optimization problem is: in, represents the k-th layer steering matrix of the remaining multicast groups other than multicast group k; ξ k,g represents the minimum expected received power of the desired user in multicast group k; represents the number of remaining desired users outside multicast group k, P AN Indicates the artificial noise emission power; A baseband signal processing module, configured to transmit a signal according to the transmitter array weight vector and the artificial noise matrix, comprising: The calculation method of artificial noise matrix is: Among them, H L (t) represents the steering vector matrix of all multicast groups, tr represents the matrix symbol; T represents the transposed conjugate matrix of the steering vector of the multicast group in the multicast group system; AN (t) represents the artificial noise matrix; t represents the current time; Steering vector for a multicast group in, Indicates the number of expected users in the multicast group in the multicast group system; According to the null space mapping criterion, when NK>L T When , the artificial noise matrix is obtained as: Where N is the number of antennas in the transmitter array; K is the number of subcarriers per transmitting antenna; I NK represents the identity matrix; Based on the transmitter array weight vector and artificial noise, the transmission signal and artificial noise are sent out through the antenna module, thus completing the transmission work.

4. A multi-carrier array antenna transmitter design server, characterized in that: including memory and processor; The memory is used to store computer-executable instructions; The processor is configured to execute the computer-executable instructions to implement the method according to any one of claims 1 to 2.

5. A computer-readable storage medium, characterized in that The computer-readable storage medium stores executable instructions, and when a computer executes the executable instructions, the method according to any one of claims 1 to 2 can be implemented.

Images