Distributed-aperture-based radar-communication integrated waveform design method

Abstract

The application relates to a distributed-aperture-based radar-communication integrated waveform design method, and belongs to the technical field of radar communication, and solves the problem that the existing technology cannot realize three-dimensional space distribution control of a waveform. The array antenna scale and the array arrangement mode are determined, a three-dimensional space coordinate system is established based on the position relationship among the array antenna, a radar target and a communication node, the positions of the radar target and the communication node in the three-dimensional space coordinate system are determined, expected waveforms at the corresponding positions are obtained through various parameters of a radar waveform and a communication waveform, the array near-field response matrix of the radar target and the communication node is calculated based on the expected waveforms of the radar and the communication, constraint conditions of a transmission waveform are obtained, the constraint conditions are solved, and finally, a radar-communication integrated waveform is obtained, arbitrary expected waveforms are simultaneously synthesized at target positions with the same distance and different directions or the same direction and different distances, and accurate control of space resources is achieved.

Description

Technical Field

[0001] This invention relates to the field of radar communication technology, and in particular to an integrated waveform design method for radar communication based on distributed aperture. Background Technology

[0002] With the continuous development of scientific theories and information technology, the differences between radar systems and communication systems in terms of spectrum occupancy, waveform processing, and transceiver channels are gradually decreasing. Problems such as system equipment redundancy, poor electromagnetic compatibility, and spectrum conflicts caused by the increase in electronic equipment are becoming increasingly significant, making the demand for integrated radar-communication systems increasingly urgent. To achieve information fusion and resource sharing among different functions, extensive research has been conducted both domestically and internationally, with a gradual shift in focus to signal integration research to achieve unified control of electromagnetic resources.

[0003] Early radar-communication integrated waveform design mainly focused on the time-frequency domain, proposing time-frequency multiplexed waveforms, radar-shared waveforms, and communication-shared waveforms; research in this area has been relatively comprehensive. With the development of antenna array technology, digital array antennas allow each element to independently generate arbitrary waveforms, making complex transmit waveform design schemes feasible. Therefore, integrated waveform design based on array antennas has become a current research hotspot. Research on radar-communication integrated waveforms based on array antennas mainly includes three types: split-array system, co-array single-beam system, and co-array multi-beam system. Among these, the split-array system divides the array into different regions to achieve radar and communication functions separately. The radar and communication waveforms can use any transmitted waveform according to functional requirements without restriction. However, this system fragments the transmitted energy, reducing the radar detection range. Furthermore, since the radar power is higher than the communication power, the radar sidelobes inevitably interfere with communication. The co-array single-beam system uses the main lobe of the transmission pattern to achieve radar function, while the sidelobes achieve communication function through amplitude and phase modulation. This method utilizes all antenna elements to simultaneously achieve radar and communication functions, improving transmission power efficiency. However, the communication function only supports line-of-sight transmission with a low transmission rate, and the communication transmission power is uncontrollable. The co-array multi-beam system generates multiple beams simultaneously to perform radar and communication functions separately. This method utilizes the spatial degrees of freedom of the array antenna, balancing radar and communication performance. However, the radar and communication operating areas are limited; when the angle between them is less than a certain range, multi-beam transmission cannot be achieved. In summary, existing integrated waveform design schemes do not fully utilize the spatial degrees of freedom of the array antenna, resulting in an inability to achieve precise control of airspace resources. Summary of the Invention

[0004] Based on the above analysis, the embodiments of the present invention aim to provide a radar-communication integrated waveform design method based on distributed aperture, in order to solve the problem that existing methods cannot achieve precise control of airspace resources.

[0005] On one hand, embodiments of the present invention provide a radar-communication integrated waveform design method based on distributed aperture, including:

[0006] Determine the size and arrangement of the array antenna, and establish a three-dimensional spatial coordinate system based on the positional relationship between the array antenna and the radar target and communication nodes;

[0007] The positions of radar targets and communication nodes in a three-dimensional spatial coordinate system are determined, and the desired waveforms at the corresponding positions are obtained through various parameters of the radar waveforms and communication waveforms.

[0008] Calculate the near-field response matrix of the radar target array and the near-field response matrix of the communication node array;

[0009] Based on the near-field response matrix of the radar target array and the near-field response matrix of the communication node array, taking the minimization of the transmission power of the integrated waveform as the criterion and the desired position synthesized waveform of the radar target and communication node as the constraint, an integrated waveform optimization model is established and the optimal radar-communication integrated waveform is obtained by solving the model.

[0010] Optionally, determining the array antenna size and array configuration, and establishing a three-dimensional spatial coordinate system based on the positional relationship between the array antenna and the radar target and communication nodes, includes:

[0011] Determine the array antenna size and array configuration;

[0012] A three-dimensional spatial coordinate system is established with the array center as the origin and the near-field boundary distance as the upper limit, ensuring that the maximum distance from the array center to the target is less than the near-field boundary distance; wherein, the target includes radar targets and communication nodes.

[0013] Optionally, determining the positions of the radar target and communication node in the three-dimensional spatial coordinate system, and obtaining the desired waveform at the corresponding position through various parameters of the radar waveform and communication waveform, includes:

[0014] The position of the radar target and the communication node in the three-dimensional spatial coordinate system is obtained based on their positions.

[0015] Based on the positions of the radar target and communication node in the three-dimensional coordinate system and the parameter information of the radar target and communication node, the desired waveforms of the radar target and communication node at their respective positions are obtained.

[0016] Optionally, the calculation of the array near-field response matrix of the radar target and the array near-field response matrix of the communication node includes:

[0017] By using the array near-field signal propagation model, the receiving model of target k within the array near-field range is obtained;

[0018] The array near-field response matrix corresponding to target k is obtained by vectorizing the receiving model;

[0019] Based on the obtained array near-field response matrix corresponding to target k, the radar target array near-field response matrix and the communication node array near-field response matrix are obtained; where target k is the radar target or communication node.

[0020] Optionally, the step of establishing an integrated waveform optimization model based on the near-field response matrix of the radar array and the near-field response matrix of the communication node array, taking minimizing the transmit power of the integrated waveform as the criterion, and using the desired position synthesized waveform of the radar target and communication node as constraints, and solving to obtain the optimal integrated radar-communication waveform, specifically includes:

[0021] Based on the desired waveform of the radar target, the constraints of the synthesized waveform of the radar target are obtained based on the near-field response matrix of the radar target array.

[0022] Based on the desired waveform of the communication node, and using the near-field response matrix of the communication node array, constraints are obtained for the synthesized waveform of the communication node; the synthesized waveform is the desired waveform at the target location.

[0023] The constraints of the radar target and the communication node are represented in a matrix to obtain the waveform synthesis constraints.

[0024] Based on waveform synthesis constraints, and according to the criterion of minimizing integrated waveform transmit power, the optimization function of the waveform is obtained;

[0025] The integrated radar-communication waveform is obtained by solving the waveform optimization function.

[0026] Optionally, obtaining the constraint conditions based on the synthesized waveform of the radar target includes:

[0027]

[0028] Among them, s f (t) represents the constraint condition for the synthesized waveform of the radar target, r mf Let x be the distance between radar target f in space and the m-th array element. m (t) represents the emitted waveform of the m-th array element, j is the imaginary unit, c is the speed of light, and f0 represents the carrier frequency of the waveform.

[0029] Optionally, obtaining the constraint conditions based on the synthesized waveform of the communication node includes:

[0030]

[0031] Among them, s c (t) represents the constraint condition for the synthesized waveform of the communication node, r mcLet x be the distance between communication node c and the m-th array element in space. m (t) represents the emitted waveform of the m-th array element, j is the imaginary unit, c is the speed of light, and f0 represents the carrier frequency of the waveform.

[0032] Optionally, the constraints based on the radar target and the communication node are represented in a matrix form to obtain waveform synthesis constraints, including:

[0033] Based on the obtained constraints of the radar target and the communication node, the composite constraints of the waveform are represented in a matrix form:

[0034] A H X = S

[0035] Where X is the matrix representation of the integrated waveform of each array element, and A = [a(x f ,y f ,z f )a(x c ,y c ,z c S = [s] is the set of near-field response matrices of the target array. f s c ] T The set of desired waveforms.

[0036] Optionally, the step of solving the obtained waveform optimization function to obtain the integrated radar-communication waveform includes:

[0037] Based on waveform synthesis constraints and the criterion of minimizing integrated waveform transmit power, the optimization model will be deformed.

[0038] Based on the deformed optimization model, the integrated waveform under waveform synthesis constraints is obtained by solving the Lagrange multiplier method.

[0039] Based on the integrated waveform under waveform synthesis constraints, and according to the constant modulus constraint, the optimization function under the constant modulus constraint is obtained;

[0040] The optimization function under constant modulus constraints is solved to obtain the integrated waveform of radar communication.

[0041] Optionally, based on waveform synthesis constraints and the criterion of minimizing the integrated waveform transmit power, the optimization model can be modified as follows:

[0042]

[0043] stA H X = S

[0044] Where X is the integrated waveform matrix, A = [a(x f ,yf ,z f )a(x c ,y c ,z c S = [s] is the set of near-field response matrices of the target array. f s c ] T The set of desired waveforms.

[0045] On the other hand, compared with the prior art, the present invention can achieve at least the following beneficial effects:

[0046] Compared with existing technologies, this invention fully utilizes the near-field layout of the array antenna and combines it with the array's near-field response matrix to synthesize waveforms with different functions at target locations at different distances in the same azimuth, simultaneously meeting the requirements of radar and communication functions for transmitted waveforms, and achieving precise control in three spatial dimensions: range, azimuth, and elevation. Furthermore, the implementation process of this invention is relatively simple and does not involve complex calculations.

[0047] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0048] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0049] Figure 1 This is a flowchart illustrating the waveform design process of an embodiment of the present invention.

[0050] Figure 2 This is a schematic diagram showing the distribution of the target scenarios for implementing the present invention;

[0051] Figure 3a This is a time-domain diagram of the synthesized waveform of the radar target position under waveform synthesis constraints, according to an embodiment of the present invention.

[0052] Figure 3b This is a time-domain diagram of the synthesized waveform at the location of communication node A under waveform synthesis constraints, according to an embodiment of the present invention.

[0053] Figure 3c This is a time-domain diagram of the synthesized waveform at the location of communication node B under waveform synthesis constraints, according to an embodiment of the present invention.

[0054] Figure 4This is a diagram illustrating the spatial similarity distribution of the desired radar waveform under waveform synthesis constraints, according to an embodiment of the present invention; wherein, Figure 4 a represents the waveform representation of the entire radiation space. Figure 4 b represents the spatial range of ±1000m around the radar target being observed;

[0055] Figure 5 This is a diagram illustrating the spatial similarity distribution of the desired waveform of communication node A under waveform synthesis constraints, according to an embodiment of the present invention; wherein, Figure 5 a represents the waveform representation of the entire radiation space. Figure 5 b represents the spatial range of ±1000m around communication node A. Figure 5 c represents the spatial range of ±5m around communication node A;

[0056] Figure 6 This is a diagram illustrating the spatial similarity distribution of the desired waveform of communication node B under waveform synthesis constraints, according to an embodiment of the present invention; wherein, Figure 6 a represents the waveform representation of the entire radiation space. Figure 6 b represents the spatial range of ±1000m around communication node B. Figure 6 c represents the spatial range of ±5m around communication node B;

[0057] Figure 7 This is a spatial energy distribution diagram under waveform synthesis constraints according to an embodiment of the present invention; wherein, Figure 7 'a' represents the energy distribution throughout the radiation space. Figure 7 b represents the energy distribution within a ±1000m radius around communication node A. Figure 7 c represents the energy distribution within a ±1000m radius around the radar target. Figure 7 d represents the energy distribution within a ±1000m radius around communication node B;

[0058] Figure 8a This is a time-domain diagram of the synthesized waveform of the radar target position under waveform synthesis constraints and constant modulus constraints, according to an embodiment of the present invention.

[0059] Figure 8b This is a time-domain diagram of the synthesized waveform at the location of communication node A under waveform synthesis constraints and constant modulus constraints, according to an embodiment of the present invention.

[0060] Figure 8c This is a time-domain diagram of the synthesized waveform at the location of communication node B under waveform synthesis constraints and constant modulus constraints, according to an embodiment of the present invention.

[0061] Figure 9 This is a spatial similarity distribution diagram of the radar desired waveform under waveform synthesis constraints and constant modulus constraints, according to an embodiment of the present invention; wherein, Figure 9 a represents the waveform representation of the entire radiation space. Figure 9b represents the spatial range of ±1000m around the radar target being observed; Figure 10 This is a spatial similarity distribution diagram of the desired waveform of communication node A under waveform synthesis constraints and constant modulus constraints, according to an embodiment of the present invention; wherein, Figure 10 a represents the waveform representation of the entire radiation space. Figure 10 b represents the spatial range of ±1000m around communication node A. Figure 10 c represents the spatial range of ±5m around communication node A;

[0062] Figure 11 This is a diagram illustrating the spatial similarity distribution of the desired waveform of communication node B under waveform synthesis constraints and constant modulus constraints, according to an embodiment of the present invention. Figure 11 a represents the waveform representation of the entire radiation space. Figure 11 b represents the spatial range of ±1000m around communication node B. Figure 11 c represents the spatial range of ±5m around communication node B;

[0063] Figure 12 This is a spatial energy distribution diagram under waveform synthesis constraints and constant mode constraints according to an embodiment of the present invention; wherein, Figure 12 'a' represents the energy distribution throughout the radiation space. Figure 12 b represents the energy distribution within a ±1000m radius around communication node A. Figure 12 c represents the energy distribution within a ±1000m radius around the radar target. Figure 12 d represents the energy distribution within a ±1000m radius around communication node B. Detailed Implementation

[0064] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0065] A specific embodiment of the present invention, such as Figure 1 As shown, a radar-communication integrated waveform design method based on distributed aperture is disclosed, specifically including:

[0066] Step S1: Determine the size and arrangement of the array antenna, and establish a three-dimensional coordinate system based on the positional relationship between the array antenna and the radar target and communication nodes;

[0067] Specifically, the array antenna has a size of M, and the total length of the array aperture is D. To ensure that the target is within the corresponding near-field range of the array, the target and the array antenna should satisfy the array near-field relationship. The array aperture D and the corresponding distance L from the target to the array center satisfy the relationship: L≤2D 2 / λ, where λ is the operating wavelength of the integrated waveform; with the array center as the origin, the 2D near-field boundary of the array is... 2 A three-dimensional spatial coordinate system (x, y, z) is established with / λ as the upper limit. The target includes radar targets and communication nodes; for example, in one specific embodiment, the number of radar targets is 1 and the number of communication nodes is 2, including communication node A and communication node B.

[0068] For example, the array antenna size, i.e., the number of array elements, is determined to be M = 1024. The array antenna is divided into 16 array elements, and each array element contains 64 uniformly arranged array elements. The element spacing is d = λ / 2, and the spacing between array elements is d. D =1200m.

[0069] Step S2: Determine the positions of the radar target and communication node in the three-dimensional spatial coordinate system, and obtain the desired waveform at the corresponding position through various parameters of the radar waveform and communication waveform;

[0070] Based on the positions of the radar target and communication node in the three-dimensional coordinate system and the parameter information of the radar target and communication node, the desired waveforms of the radar target and communication node at their respective positions are obtained.

[0071] Specifically, the simulation parameters for the radar target and communication node are as follows:

[0072] Table 1. Simulation parameters related to integrated waveform design

[0073]

[0074] The parameter information of the radar target and the communication node is obtained; the radar target parameters include signal type, bandwidth, and pulse width; the communication node parameters include modulation method, number of symbols, modulation order, and power difference with the radar waveform.

[0075] The radar target's position in a three-dimensional Cartesian coordinate system: (x r y r z r The positions of the communication nodes in a three-dimensional Cartesian coordinate system: (x) c y c z c The desired radar waveform s is obtained by using the position coordinates of the radar target in a three-dimensional Cartesian coordinate system and the radar parameters. r The desired communication waveform s is obtained by using the position coordinates of the communication node in a three-dimensional Cartesian coordinate system and the communication parameters. c .

[0076] Step S3: Calculate the array near-field response matrix of the radar target and the array near-field response matrix of the communication node;

[0077] Specifically, when the radar target is within the near-field range of the array, the received waveform at the target's location is a spherical wave. The phase and amplitude of this waveform are both related to the propagation distance; therefore, it is necessary to calculate the propagation distance of each array element and its corresponding response matrix. This includes:

[0078] The near-field signal propagation model of the array is as follows:

[0079]

[0080] Where t is the time of the transmitted waveform, A is the amplitude of the transmitted waveform, r is the distance between the array element and the target, f is the frequency of the transmitted waveform, j is the imaginary unit, and λ is the operating wavelength of the integrated waveform. It is worth noting that, as shown by the propagation model, the amplitude attenuation and phase delay of the received waveform at the radar target location are both affected by the distance r.

[0081] For an array antenna with M elements, any target k in space is located within the near-field range of the array antenna. According to formula (1), the received signal model of any target k can be expressed as:

[0082]

[0083] Where, r mk Let x be the distance between the m-th array element and any target k. m (t) represents the emission waveform of the m-th array element, and c represents the speed of light.

[0084] The vectorized representation of the received signal for any target k is as follows:

[0085]

[0086] Where x(n) is the nth sampling point of the integrated waveform, Let be the array near-field response matrix corresponding to any target k. Then, by combining simulation parameters, the radar target array near-field response matrix a can be obtained. f and the near-field response matrix a of the communication node array c .

[0087] Therefore, in the three-dimensional coordinate system, the array near-field response matrix corresponding to any target k is:

[0088]

[0089] Where, r m Let be the distance between the target at any position (x, y, z) in space and the m-th array element. The propagation phase corresponds to the distance from the m-th array element to any position.

[0090] In this embodiment, the near-field response matrix of the radar target array and the near-field response matrix of the communication node array are obtained based on the array near-field response matrix corresponding to the target k; wherein, the target k is the radar target or the communication node.

[0091] Step S4: Based on the near-field response matrix of the radar target array and the near-field response matrix of the communication node array, with the criterion of minimizing the transmission power of the integrated waveform and the desired position synthesized waveform of the radar target and communication node as constraints, establish an integrated waveform optimization model and solve it to obtain the optimal integrated radar-communication waveform.

[0092] Specifically, for radar targets in space, based on the near-field response matrix of the radar array, the synthesized waveform at its location is required to be a linear frequency modulation (LFM) waveform. Therefore, the waveform must satisfy the following constraints:

[0093]

[0094] Using the array near-field response matrix, equation (5) can be expressed in matrix form as follows: Where X is the matrix representation of the integrated waveform of each array element.

[0095] For a communication node in space, the synthesized waveform at its location must be a communication waveform carrying information, and the waveform must satisfy the following constraints:

[0096]

[0097] Using the array near-field response matrix, equation (6) can be expressed in matrix form as follows:

[0098] Therefore, based on the conditions satisfied by the integrated waveform of the radar target and communication node, the waveform synthesis constraint is constructed as follows: A H X = S,

[0099] Where X is the integrated waveform matrix, A = [a(x f ,y f ,z f )a(x c ,y c ,z c S = [s] is the set of near-field response matrices of the target array. f s c ] T Let be the set of desired waveforms; in order to satisfy the waveform synthesis constraint under the minimum transmit power, the F-norm of the integrated waveform is minimized, and the optimization model can be specifically expressed as:

[0100]

[0101] Solving formula (7) using the Lagrange multiplier method yields the analytical solution as follows:

[0102] X0=A(A H A) -1 S (8)

[0103] The synthesized waveform is the desired waveform at the target location.

[0104] It should be noted that in the parameters in Table 1 and Figure 2 In the scenario shown, the method is simulated and tested to measure the difference between the actual waveform s and the radar's desired waveform s. f To assess the similarity between the actual waveform s and the expected waveform s in communication, pulse compression is performed on the actual waveform s, and the peak pulse compression value is used as the evaluation metric. c The similarity between (n) is used to decode the actual waveform s, and the bit error rate is used as the evaluation index. The simulation results are shown in Figure 3. Figure 4 , Figure 5 , Figure 6 and Figure 7 As shown, Figure 3 is the time-domain diagram of the composite waveform of the desired location, sub-Figure 3.a is the time-domain diagram of the composite waveform of the radar target location, sub-Figure 3.b is the time-domain diagram of the composite waveform of the communication node A location, and sub-Figure 3.c is the time-domain diagram of the composite waveform of the communication node B location. Figure 4 This is a spatial similarity distribution diagram of the radar's desired waveform. Figure 5 The spatial similarity distribution of the expected waveform for communication node A is shown in the diagram. Figure 6 The spatial similarity distribution of the expected waveform for communication node B is shown in the diagram. Figure 7 Figure 3 shows the spatial energy distribution map. As can be seen from Figure 3, the desired waveform was synthesized without error at the designated locations of both the radar target and the communication node. Radar and communication functions were achieved at locations with the same direction but different distances, overcoming the limitations of the space operating area. Figure 4 It can be seen that in the radiation space, only the radar target location and its vicinity exhibit good pulse compression performance with high pulse compression peak values, while other areas in the space cannot obtain effective pulse compression peak values, failing to satisfy the radar waveform similarity requirement. To further analyze the waveform distribution around the radar target, the radiation space is narrowed to a range of ±1000m around the target. In the right figure, the red boundary represents the envelope of the overlapping area of ​​the transmitted beams of all array elements, defined as the ideal radar performance boundary. Observation reveals that the waveform similarity region matches the ideal radar performance boundary. Based on... Figure 5 It can be seen that in the radiation space, the bit error rate of the location of communication node A and its vicinity is 0, matching the ideal communication performance boundary, and exhibiting a striped pattern distribution, demonstrating good spatial similarity. Based on... Figure 6It can be seen that in the radiation space, the bit error rate of the location of communication node B and its vicinity is 0, matching the ideal communication performance boundary, and exhibiting a striped pattern distribution, demonstrating good spatial similarity. Based on... Figure 7 It can be seen that in the radiation space, energy accumulation forms around the desired location, improving the utilization efficiency of the transmission power, further supporting the realization of multi-functional space capabilities, and reducing interference and the probability of being detected in undesired areas. Meanwhile, simulation results show that the peak-to-average power ratio of the integrated waveform is around 2.83, and the waveform amplitude oscillates violently, requiring the application of constant mode constraints. The constant mode constraint introduced for the integrated waveform is as follows:

[0105]

[0106] Where N is the number of sampling points of the integrated waveform, M is the number of array elements, and x m (n) represents the nth sample of the transmitted waveform of the m-th array element.

[0107] Under the criterion of minimizing the transmit power of the integrated waveform, and combining waveform synthesis constraints and constant mode constraints, the waveform optimization model can be modeled as follows:

[0108]

[0109] Since the constant modulus constraint is non-convex, the waveform optimization model is decomposed into two sub-optimization problems using the alternating projection method for iterative solution. Under the waveform synthesis constraint, the sub-optimization problems are:

[0110]

[0111] Among them, X (i-1) For the (i-1)th iteration of the integrated waveform matrix,

[0112] The analytical solution to this optimization problem can be directly obtained using the Lagrange multiplier method:

[0113]

[0114] Then the analytical solution Substituting the constant modulus constraint into the sub-optimization problem, the optimization function is specifically expressed as follows:

[0115]

[0116] The analytical solution to this sub-optimization problem is:

[0117]

[0118] in, For the transmission power of the integrated waveform, ρ eff Minimum power percentage, Let X be the transmission power of the integrated waveform X0 in formula (8), which is the minimum transmission power required to satisfy the waveform synthesis constraint. To further satisfy the constant mode constraint, more energy needs to be provided to the integrated waveform, that is, to provide degrees of freedom to the null space of A to generate waveform X. ⊥ Without violating the waveform synthesis constraints, X0+X ⊥ It satisfies the constant modulus constraint.

[0119] By iteratively solving the two sub-optimization problems, when the results of the two iterations satisfy the convergence condition ||X (i) -X (i-1) || F ≤10 -4 Alternatively, stop the loop when the maximum number of iterations is reached to obtain the final result.

[0120] When ρ eff When the value is 0.5, the simulation results are shown in Figure 8. Figure 9 , Figure 10 , Figure 11 and Figure 12 As shown, Figure 8 is the time-domain diagram of the composite waveform at the desired location, sub-Figure 8.a is the time-domain diagram of the composite waveform at the radar target location, sub-Figure 8.b is the time-domain diagram of the composite waveform at the location of communication node A, and sub-Figure 8.c is the time-domain diagram of the composite waveform at the location of communication node B. Figure 9 This is a spatial similarity distribution diagram of the radar's desired waveform. Figure 10 The spatial similarity distribution of the expected waveform for communication node A is shown in the diagram. Figure 11 The spatial similarity distribution of the expected waveform for communication node B is shown in the diagram. Figure 12 Figure 8 shows the spatial energy distribution. As can be seen from Figure 8, under the condition of satisfying the constant modulus constraint of the waveform, the desired waveform was synthesized without error at the specified locations of both the radar target and the communication node, achieving precise control in three-dimensional space. Figure 9 It can be seen that in the radiation space, only the radar target location and its vicinity exhibit good pulse compression performance with high pulse compression peak values, while other areas in the space cannot obtain effective pulse compression peak values, failing to satisfy the radar waveform similarity requirement. To further analyze the waveform distribution around the radar target, the radiation space is narrowed to a range of ±1000m around the target. In the right figure, the red boundary represents the envelope of the overlapping area of ​​the transmitted beams of all array elements, defined as the ideal radar performance boundary. Observation reveals that, compared to... Figure 4 Compared to the previous model, the waveform similarity region is smaller, but it still matches the ideal radar performance boundary. Based on... Figure 10 It can be seen that in the radiation space, the bit error rate of the location of communication node A and its vicinity is 0, matching the ideal communication performance boundary, and exhibiting a striped pattern distribution, demonstrating good spatial similarity. Based on... Figure 11It can be seen that in the radiation space, the bit error rate of the location of communication node B and its vicinity is 0, matching the ideal communication performance boundary, and exhibiting a striped pattern distribution, demonstrating good spatial similarity. Based on... Figure 12 It can be seen that in the radiation space, due to the increase in transmission power to meet the waveform constant mode constraint, the energy in the undesired region of space is slightly increased, but energy accumulation still forms around the desired location, which can support the realization of multiple functions in space.

[0121] The simulations above show that, compared with existing methods, the present invention can utilize the near-field effect of array antennas to perform integrated waveform design, simultaneously synthesizing arbitrary desired waveforms at target locations with different directions at the same distance and with different distances at the same direction, thus meeting the requirements of radar and communication functions for transmitted waveforms and achieving precise control of airspace resources.

[0122] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0123] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A waveform design method for integrated radar and communication based on distributed aperture, characterized in that, include: Determine the size and arrangement of the array antenna, and establish a three-dimensional spatial coordinate system based on the positional relationship between the array antenna and the radar target and communication nodes; The positions of radar targets and communication nodes in a three-dimensional spatial coordinate system are determined, and the desired waveforms at the corresponding positions are obtained through various parameters of the radar waveforms and communication waveforms. Calculate the array near-field response matrix of the radar target and the array near-field response matrix of the communication node; Based on the near-field response matrices of the radar target array and the communication node array, and taking the minimization of the transmitted power of the integrated waveform as the criterion, and the desired positional composite waveforms of the radar target and communication nodes as constraints, an integrated waveform optimization model is established and solved to obtain the optimal integrated radar-communication waveform, specifically including: Based on the desired waveform of the radar target, the constraints of the synthesized waveform of the radar target are obtained based on the near-field response matrix of the radar target array. Based on the desired waveform of the communication node, and using the near-field response matrix of the communication node array, constraints are obtained for the synthesized waveform of the communication node; the synthesized waveform is the desired waveform at the target location. The constraints of the radar target and the communication node are represented in a matrix to obtain the waveform synthesis constraints. Based on waveform synthesis constraints, and according to the criterion of minimizing integrated waveform transmit power, the optimization function of the waveform is obtained; The integrated radar-communication waveform is obtained by solving the waveform optimization function.

2. The integrated radar-communication waveform design method based on distributed aperture as described in claim 1, characterized in that, The process of determining the array antenna size and arrangement, and establishing a three-dimensional spatial coordinate system based on the positional relationship between the array antenna and the radar target and communication nodes, includes: Determine the array antenna size and array configuration; A three-dimensional spatial coordinate system is established with the array center as the origin and the near-field boundary distance as the upper limit, ensuring that the maximum distance from the array center to the target is less than the near-field boundary distance; wherein, the target includes radar targets and communication nodes.

3. The integrated radar-communication waveform design method based on distributed aperture as described in claim 1, characterized in that, The process of determining the positions of radar targets and communication nodes in a three-dimensional spatial coordinate system, and obtaining the desired waveform at the corresponding positions using various parameters of the radar and communication waveforms, includes: The position of the radar target and the communication node in the three-dimensional spatial coordinate system is obtained based on their positions. Based on the positions of the radar target and communication node in the three-dimensional coordinate system and the parameter information of the radar target and communication node, the desired waveforms of the radar target and communication node at their respective positions are obtained.

4. The integrated radar-communication waveform design method based on distributed aperture as described in claim 1, characterized in that, The calculation of the array near-field response matrix of the radar target and the array near-field response matrix of the communication node includes: By using the array near-field signal propagation model, the receiving model of target k within the array near-field range is obtained; The array near-field response matrix corresponding to target k is obtained by vectorizing the receiving model; Based on the obtained array near-field response matrix corresponding to target k, the radar target array near-field response matrix and the communication node array near-field response matrix are obtained; where target k is the radar target or communication node.

5. The integrated waveform design method for radar and communication based on distributed aperture as described in claim 1, characterized in that, The constraints obtained based on the synthesized waveform of the radar target include: Among them, s f (t) represents the constraint condition for the synthesized waveform of the radar target, r mf Let x be the distance between radar target f in space and the m-th array element. m (t) represents the emitted waveform of the m-th array element, j is the imaginary unit, c is the speed of light, and f0 represents the carrier frequency of the waveform.

6. The integrated waveform design method for radar and communication based on distributed aperture as described in claim 1, characterized in that, The constraints obtained based on the synthesized waveform of the communication node include: Among them, s c (t) represents the constraint condition for the synthesized waveform of the communication node, r mc Let x be the distance between communication node c and the m-th array element in space. m (t) represents the emitted waveform of the m-th array element, j is the imaginary unit, c is the speed of light, and f0 represents the carrier frequency of the waveform.

7. The radar-communication integrated waveform design method based on distributed aperture according to claim 5 or 6, characterized in that, The constraints based on the radar target and the communication node are represented in a matrix form to obtain waveform synthesis constraints, including: Based on the obtained constraints of the radar target and the communication node, the composite constraints of the waveform are represented in a matrix form: A H X=S Where X is the matrix representation of the integrated waveform of each array element, and A = [a(x f ,y f ,z f )a(x c ,y c ,z c S is the set of near-field response matrices of the target array, where S = [s f s c ] T The set of desired waveforms.

8. The integrated waveform design method for radar and communication based on distributed aperture as described in claim 1, characterized in that, The process of obtaining the integrated radar-communication waveform by solving the obtained waveform optimization function includes: Based on waveform synthesis constraints and the criterion of minimizing integrated waveform transmit power, the optimization model will be deformed. Based on the deformed optimization model, the integrated waveform under waveform synthesis constraints is obtained by solving the Lagrange multiplier method. Based on the integrated waveform under waveform synthesis constraints, and according to the constant modulus constraint, the optimization function under the constant modulus constraint is obtained; The optimization function under constant modulus constraints is solved to obtain the integrated waveform of radar communication.

9. The integrated waveform design method for radar and communication based on distributed aperture as described in claim 8, characterized in that, Based on waveform synthesis constraints and the criterion of minimizing integrated waveform transmit power, the optimization model is modified as follows: s.t.A H X=S Where X is the integrated waveform matrix, A = [a(x f ,y f ,z f ) a(x c ,y c ,z c S = [s] is the set of near-field response matrices of the target array. f s c ] T The set of desired waveforms.

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