A radar communication system and receiver joint filter design method and system

Abstract

The application provides a radar communication system and receiver joint filter design method and system, the method comprises the following steps: constructing the filter of the working scene of the integrated radar communication system and the JRC-CWG-RF model; when the target and the integrated system move relative to each other in the working scene, the sidelobe performance design optimization criterion is designed according to the filter output of the radar receiving end of the integrated radar communication system; the optimization problem is constructed according to the optimization criterion; the optimization problem is solved by using the AO-KKT-MM algorithm, the constraint parameters of the JRC-CWG-RF model are adjusted, and the filter of the adaptive JRC-CWG-RF model is obtained. The system is based on the above method. By constructing the working scene and the JRC-CWG-RF model, the filter output of the JRC-CWG-RF model has a low sidelobe level, the parameter value of the filter is adjusted according to the constraint, the PAPR of a radar communication system transmission waveform can be effectively limited, the application also realizes radar detection while realizing communication function, and the performance of the integrated system is improved through joint optimization.

Description

Technical Field

[0001] This invention relates to the intersection of radar and communications, and in particular to a method and system for designing a joint filter for a radar communication system and receiver. Background Technology

[0002] The statements in this section are merely background information relating to this disclosure and do not necessarily constitute prior art.

[0003] An integrated radar-communication system combines radar and communication technologies to improve the performance of both the platform's radar and communication equipment in congested spectrum environments. Therefore, in real-world scenarios, integrated radar-communication devices often have to work alongside other electronic devices. For example, if the integrated radar-communication device and a communication device operate in the same spatial and temporal environment, the signals emitted by the communication device may interfere with the integrated system, leading to a decrease in its performance.

[0004] To address this problem, many scholars have proposed using Successive Interference Cancellation (SIC) technology to eliminate communication interference signals received by an integrated system. This technology assumes that the integrated system knows the signal transmitted by the communication system in advance. When it receives a communication interference signal, it subtracts the interference signal to achieve interference cancellation. However, since actual communication channels are often frequency-selective fading channels, the communication interference signal received by the integrated system will differ significantly from the signal transmitted by the communication system. To achieve communication interference signal cancellation, the integrated system needs to estimate the Channel State Information (CSI) with extremely high accuracy to accurately estimate and eliminate the interference signal. Therefore, the above method is very difficult to implement in practice.

[0005] To avoid accurately estimating channel state information, designing a radar-communication integrated complementary waveform group and receiver joint filter has become an urgent problem to be solved. Summary of the Invention

[0006] This invention provides a method and system for designing a joint filter for a radar communication system and receiver. By constructing a working scenario and a JRC-CWG-RF model, the filter output of the JRC-CWG-RF model has a low sidelobe level. The filter parameter values ​​are adjusted according to constraints, so that the PAPR of the transmitted waveform of a radar communication system can be effectively limited.

[0007] The technical solution for achieving the objective of this invention is as follows:

[0008] On one hand, the present invention provides a method for designing a joint filter for a radar communication system and receiver, comprising:

[0009] Constructing the working scenario of an integrated radar and communication system and the filter of the JRC-CWG-RF model;

[0010] When the target moves relative to the integrated system in the working scenario, the sidelobe performance design optimization criteria are based on the output of the radar receiver filter of the integrated radar communication system.

[0011] Construct an optimization problem based on the aforementioned optimization criteria;

[0012] The optimization problem is solved using the AO-KKT-MM algorithm. By adjusting the constraint parameters of the JRC-CWG-RF model, a filter adapted to the JRC-CWG-RF model is obtained.

[0013] Based on one aspect, in one embodiment of the present invention, the filter for constructing the working scenario of the integrated radar-communication system and the JRC-CWG-RF model includes:

[0014] The receiver of the integrated communication system receives the signal emitted by the JRC-CWG-RF model;

[0015] The transmitter of the integrated communication system transmits JRC-CWG signals to detect weak and strong targets in the scene, while simultaneously transmitting communication information;

[0016] The filter output of the JRC-CWG-RF model has a low sidelobe level to prevent the echo signal of weak targets in the working scenario from being overwhelmed by the sidelobe of the echo signal of strong targets.

[0017] The transmitted JRC-CWG signal and its receiving filter are jointly designed to suppress interference signals while simultaneously enabling target detection and communication information transmission.

[0018] Based on one aspect, in one embodiment of the present invention, in the signal received by the receiver of the integrated communication system from the JRC-CWG-RF model, the signal received by the receiver of the integrated communication system is represented as follows:

[0019] Formula (1)

[0020] In formula (1), , indicating the first of each group of JRC-CWG signals One transmitted waveform, contained in a set of JRC-CWGs One transmitted waveform, front The waveform is the optimized waveform (OW), then... The waveforms are radar communication waveforms (RCW), and have ; Indicates transpose. The number of samples, This indicates the Doppler frequency shift caused by the relative motion between the target and the integrated platform. Represents the complex scattering coefficients, which include path loss and the target's RCS. This represents the vector of Gaussian white noise received by the radar receiver of the integrated system, with a mean of 0 and a variance of . , Indicates the first The total interference signal within each transmitting PRI, and the interference signals within different transmitting PRIs are uncorrelated;

[0021] In the communication integrated system, the receiver receives the signal emitted by the JRC-CWG-RF model. The receiver then... The signal echo within each transmitted PRI is processed by the filter described above. Summing the filter output information within each transmitting PRI, we obtain formula (2):

[0022] Formula (2)

[0023] In formula (2), Indicates normalized Doppler.

[0024]

[0025] Indicates by The convolution matrix formed by the waveform. , Definition and resemblance, This represents the Gaussian white noise vector output by the filter;

[0026] In the joint design of the transmitted JRC-CWG signal and its receiving filter, the complementary cross-correlation function between the transmitted JRC-CWG signal and the filter is expressed as follows:

[0027] Formula (3)

[0028] In formula (3), Indicates by The convolution matrix formed by the waveform. Indicates normalized Doppler. Indicates the first The filter used by each transmitting PRI.

[0029] Based on one aspect, in one embodiment of the present invention, when the target and the integrated system move relative to each other in the working scenario, the sidelobe performance design optimization criteria based on the radar receiver filter output of the integrated radar-communication system include:

[0030] The template matching method is used to optimize the sidelobe performance of the radar receiver filter output of the integrated system when there is a relative velocity between the target and the integrated system.

[0031] Based on one aspect, in one embodiment of the present invention, the optimization of the sidelobe performance of the radar receiver filter output of the integrated system when there is a relative velocity between the target and the integrated system using the template matching method includes:

[0032] The receiver input interference plus noise power of the integrated radar and communication system is expressed as follows:

[0033] Formula (4)

[0034] In formula (4), This indicates the conjugate transpose. Indicates the first The total interference signal within the PRI transmission. This represents the vector of Gaussian white noise received by the radar receiver of the integrated system.

[0035] The interference plus noise power in the receiver output sidelobe performance of the integrated radar and communication system is expressed as follows:

[0036] Formula (5)

[0037] In formula (5), This represents the Gaussian white noise vector output by the filter. ;

[0038] waveform The peak-to-average power ratio (PAPR) is expressed as:

[0039] Formula (6)

[0040] In formula (6), This indicates the first JRC-CWG signal in each group. One transmitted waveform, This indicates the conjugate transpose. The number of samples;

[0041] waveform The peak-to-average power ratio (PAPR) constraint is expressed as:

[0042] Formula (7)

[0043] In formula (7), This indicates the maximum acceptable waveform PAPR value for the integrated communication system.

[0044] Based on one aspect, in one embodiment of the present invention, constructing the optimization problem according to the optimization criterion includes: constructing the optimization problem according to the optimization criterion of the following formula (8).

[0045]

[0046] In formula (8), , Indicates the constraint improvement factor. express The minimum value, This indicates that the power of each transmitted waveform is constrained. Indicates the constraint PAPR. This indicates the maximum acceptable waveform PAPR value for the transmitter of the integrated system. Constrain the peak value of the main lobe output of the receiver filter; This indicates the first JRC-CWG signal in each group. One transmitted waveform, Indicates the first The filter used by each transmitting PRI.

[0047] Based on this, in one embodiment of the present invention, the optimization problem is rewritten using the penalty function method, and formula (8) is rewritten as formula (9):

[0048]

[0049] In formula (9), Indicates the penalty factor. Indicates the constraint improvement factor. , This indicates that the power of each transmitted waveform is constrained. The constraint PAPR is represented.

[0050] Based on one aspect, in one embodiment of the present invention, the step of solving the optimization problem using the AO-KKT-MM algorithm includes:

[0051] Set algorithm termination threshold The optimization problem is divided into subproblem one and subproblem two, wherein subproblem one is represented as:

[0052] Formula (10)

[0053] In formula (10), Indicates the first The filter used by each transmitting PRI This indicates the conjugate transpose. This indicates the first JRC-CWG signal in each group. One transmitted waveform;

[0054] Subproblem two is represented as follows:

[0055] Formula (11)

[0056] In formula (11), Indicates the first The filter used by each transmitting PRI This indicates the conjugate transpose. This indicates the first JRC-CWG signal in each group. One transmitted waveform.

[0057] Based on one aspect, in one embodiment of the present invention, the step of solving the optimization problem using the AO-KKT-MM algorithm includes:

[0058] Set algorithm termination threshold The optimization problem is divided into subproblem one and subproblem two, wherein subproblem one is represented as:

[0059]

[0060] In the above formula, Indicates the first The filter used by each transmitting PRI This indicates the conjugate transpose. This indicates the first JRC-CWG signal in each group. One transmitted waveform;

[0061] Subproblem two is represented as follows:

[0062]

[0063] In the above formula, Indicates the first The filter used by each transmitting PRI This indicates the conjugate transpose. This indicates the first JRC-CWG signal in each group. One transmitted waveform;

[0064] The optimal solution to subproblem one is obtained by solving the KKT algorithm, and the optimal solution to subproblem two is obtained by solving the MM algorithm.

[0065] The optimal solution one is:

[0066] Formula (10)

[0067] In formula (10), It is a diagonal loading term that guarantees the invertibility of the matrix;

[0068] , , , ;

[0069] Wherein, the second subproblem is equivalent to:

[0070]

[0071] The second optimal solution is calculated using the MM algorithm. ;

[0072] when When the algorithm terminates, output Otherwise ;

[0073] According to the output Adjust the constraint parameters of the JRC-CWG-RF model to obtain a filter that fits the JRC-CWG-RF model.

[0074] On the other hand, the present invention provides a joint filter design system for radar communication system and receiver, comprising: a construction unit, an optimization unit, and a processing unit;

[0075] The construction unit constructs the working scenario of the radar-communication integrated system and the filter of the JRC-CWG-RF model; the construction unit also constructs an optimization problem according to the optimization criteria of the optimization unit;

[0076] The optimization unit designs optimization criteria based on the sidelobe performance of the radar receiver filter output of the radar communication integrated system when the target and the integrated system move relative to each other in the working scenario.

[0077] The processing unit uses the AO-KKT-MM algorithm to solve the optimization problem, adjusts the constraint parameters of the JRC-CWG-RF model, and obtains a filter that fits the JRC-CWG-RF model.

[0078] Compared with the prior art, the beneficial effects of the present invention are:

[0079] This invention constructs a working scenario and a JRC-CWG-RF model. The filter output of the JRC-CWG-RF model has a low sidelobe level. The filter parameter values ​​are adjusted according to constraints, which can effectively limit the PAPR of the transmitted waveform of a radar communication system. This invention also performs radar detection while realizing communication functions. The performance of the integrated system is improved by jointly optimizing the radar communication system and the receiving filter. Attached Figure Description

[0080] Figure 1 A flowchart illustrating a method for designing a joint filter for a radar communication system and receiver, provided in an embodiment of the present invention;

[0081] Figure 2 A schematic diagram illustrating the working scenario of constructing the integrated radar and communication system for this invention;

[0082] Figure 3 The CCCF of the JRC-CWG-RF model of this invention varies with the number of OWs. Changes;

[0083] Figure 4 CCCF of the JRC-CWG-RF model of this invention constraint Changes;

[0084] Figure 5 The CCCF of the JRC-CWG-RF model of this invention is subject to PAPR constraints. Changes;

[0085] Figure 6 For the PSLR of the present invention and constraints The trade-off curve;

[0086] Figure 7 Constraints of PSLR and PAPR in this invention The trade-off curve;

[0087] Figure 8 The PSLR curve as a function of Doppler and different weight vectors of the present invention Relationship;

[0088] Figure 9 The PSLR variation curve with Doppler in this invention is compared with different... Relationship;

[0089] Figure 10 The PSLR variation curve with Doppler in this invention is compared with different... Relationship;

[0090] Figure 11The PSLR variation curve with Doppler in this invention is compared with different... Relationship;

[0091] Figure 12 This invention describes the relationship between the PSLR of the CCCF of the JRC-CWG-RF model and the communication rate when the target velocity is 0.

[0092] Figure 13 For the present invention, when the target speed is The relationship between the PSLR of CCCF in the JRC-CWG-RF model and the communication rate. Detailed Implementation

[0093] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. However, it should be noted that these embodiments are not intended to limit the present invention. Equivalent changes or substitutions in function, method, or structure made by those skilled in the art based on these embodiments are all within the scope of protection of the present invention.

[0094] Please see Figure 1 and Figure 2 , Figure 1 This is a flowchart illustrating a method for designing a joint filter for a radar communication system and receiver, as provided in an embodiment of the present invention. Figure 2 This illustration shows the working scenario of the integrated radar and communication system constructed according to the present invention. An embodiment of the present invention provides a method for designing a joint filter for a radar communication system and receiver, including:

[0095] Step 1: Construct the working scenario of the radar-communication integrated system and the filter of the JRC-CWG-RF model.

[0096] The above-mentioned working scenario for constructing an integrated radar and communication system and the filters for the JRC-CWG-RF model include:

[0097] The receiver of the integrated communication system receives signals emitted by the JRC-CWG-RF model;

[0098] The transmitter of the integrated communication system transmits JRC-CWG signals to detect weak and strong targets in the scene, while simultaneously transmitting communication information;

[0099] The filter output of the JRC-CWG-RF model has a low sidelobe level to prevent the echo signal of weak targets in the working scene from being overwhelmed by the sidelobe of the echo signal of strong targets.

[0100] The transmitted JRC-CWG signal and its receiving filter were jointly designed to suppress interference signals while simultaneously enabling target detection and communication information transmission.

[0101] It should be noted that the JRC-CWG-RF model in this embodiment of the invention is an abbreviation for the radar-communication integrated complementary waveform group and receiving filter model.

[0102] In the above-mentioned integrated communication system, the signal received by the receiver of the JRC-CWG-RF model is represented as follows:

[0103] Formula (1)

[0104] In formula (1), , indicating the first JRC-CWG signal in each group One transmitted waveform, contained in a set of JRC-CWGs One transmitted waveform, front The waveform is the optimized waveform (OW), then... The waveforms are radar communication waveforms (RCW), and have ; Indicates transpose. The number of samples, This indicates the Doppler frequency shift caused by the relative motion between the target and the integrated platform. Represents the complex scattering coefficients, which include path loss and the target's RCS. This represents the vector of Gaussian white noise received by the radar receiver of the integrated system, with a mean of 0 and a variance of . , Indicates the first The total interference signal within each transmitting PRI, and the interference signals within different transmitting PRIs are uncorrelated;

[0105] In the receiver of the integrated communication system, when receiving the signal emitted by the JRC-CWG-RF model, the receiver... The signal echo within each transmitted PRI is processed using a filter. Summing the filter output information within each transmitting PRI, we obtain formula (2):

[0106] Formula (2)

[0107] In formula (2), Indicates normalized Doppler. Indicates the first The total interference signal within each transmitting PRI, and the interference signals within different transmitting PRIs are uncorrelated;

[0108]

[0109] Indicates by The convolution matrix formed by the waveform. , This represents the Gaussian white noise vector output by the filter;

[0110] In the joint design of the transmitted JRC-CWG signal and its receiving filter, the complementary cross-correlation function between the transmitted JRC-CWG signal and the filter is expressed as:

[0111] Formula (3)

[0112] In formula (3), Indicates by The convolution matrix formed by the waveform. Indicates normalized Doppler. Indicates the first The filter used by each transmitting PRI.

[0113] In step one, the IRC system receiving signal model of this embodiment represents an integrated system transmitting a JRC-CWG to detect vehicles and drones in the scene, while simultaneously transmitting communication information. To prevent the echo signal of weak targets (drones) from being overwhelmed by the sidelobes of the echo signal of strong targets (vehicles), the JRC-CWG receiving filter output needs to have a low sidelobe level. Other communication base stations also exist in the scene, and their transmitted waveforms interfere with the integrated system. Therefore, the transmitted JRC-CWG and its receiving filter need to be jointly designed to suppress interference signals while simultaneously detecting targets and transmitting communication information.

[0114] Step 2: When the target and the integrated system are in relative motion in the working scenario, design optimization criteria based on the sidelobe performance of the radar receiver filter output of the radar communication integrated system.

[0115] When the target and the integrated system are in relative motion in the above working scenario, the design optimization criteria for the sidelobe performance of the radar receiver filter output of the radar communication integrated system include: using template matching method to optimize the sidelobe performance of the radar receiver filter output of the integrated system when there is relative motion velocity between the target and the integrated system.

[0116] The above-mentioned template matching method is used to optimize the sidelobe performance of the radar receiver filter output of the integrated system when there is a relative velocity between the target and the integrated system, including:

[0117] The receiver input interference plus noise power of a radar-communication integrated system is expressed as:

[0118] Formula (4)

[0119] In formula (4), This indicates the conjugate transpose. Indicates the first The total interference signal within the PRI transmission. This represents the vector of Gaussian white noise received by the radar receiver of the integrated system.

[0120] The interference plus noise power in the receiver output sidelobe performance of a radar-communication integrated system is expressed as:

[0121] Formula (5)

[0122] In formula (5), This represents the Gaussian white noise vector output by the filter. ;

[0123] waveform The peak-to-average power ratio (PAPR) is expressed as:

[0124] Formula (6)

[0125] In formula (6), This indicates the first JRC-CWG signal in each group. One transmitted waveform, This indicates the conjugate transpose. The number of samples;

[0126] waveform The peak-to-average power ratio (PAPR) constraint is expressed as:

[0127] Formula (7)

[0128] In formula (7), This indicates the maximum acceptable waveform PAPR value for an integrated communication system.

[0129] In practical applications, embodiments of the present invention are designed and optimized based on the sidelobe performance design criteria of the radar receiver filter output of the integrated system when there is a relative velocity between the target and the integrated system. Specifically, step two includes the following sub-steps:

[0130] Step 2.1: Optimize the sidelobe performance of the radar receiver filter output of the integrated system when there is a relative velocity between the target and the integrated system using the template matching method; discretize the relative velocity range to be optimized when designing JRC-CWG-RF, and define the set of velocities to be optimized as follows:

[0131]

[0132] In the above formula For set The number of points in the equation. Let the relative velocity be denoted as . The expected CCCF template is:

[0133]

[0134] In the formula To normalize the Doppler frequency, λ is the wavelength.

[0135] Step 2.2: The input interference plus noise power of the integrated system radar receiver is expressed as:

[0136]

[0137] The power of interference plus noise output from the radar receiver of the integrated system is expressed as:

[0138]

[0139] waveform PAPR is represented as:

[0140]

[0141] The constraints on PAPR are expressed as follows:

[0142]

[0143] in The maximum acceptable waveform PAPR for the transmitter of the integrated system.

[0144] Step 3: Construct the optimization problem based on the optimization criteria.

[0145] The above-mentioned construction of optimization problems based on optimization criteria includes: constructing optimization problems based on the following formula (8) optimization criteria.

[0146] Formula (8)

[0147] In formula (8), , Indicates the constraint improvement factor. express The minimum value, This indicates that the power of each transmitted waveform is constrained. Indicates the constraint PAPR. This indicates the maximum acceptable waveform PAPR value for the transmitter of the integrated system. Constrain the peak value of the main lobe output of the receiver filter; This indicates the first JRC-CWG signal in each group. One transmitted waveform, Indicates the first The filter used by each transmitting PRI.

[0148] In this embodiment of the invention, the optimization problem is rewritten using the penalty function method, and formula (8) is rewritten as formula (9):

[0149] Formula (9)

[0150] In formula (9), Indicates the penalty factor. Indicates the constraint improvement factor. , This indicates that the power of each transmitted waveform is constrained. The constraint PAPR is represented.

[0151] Step 4: Solve the optimization problem using the AO-KKT-MM algorithm, adjust the constraint parameters of the JRC-CWG-RF model, and obtain a filter that fits the JRC-CWG-RF model.

[0152] The above-mentioned AO-KKT-MM algorithm is used to solve the optimization problem, including:

[0153] Set algorithm termination threshold The optimization problem is broken down into subproblem one and subproblem two, where subproblem one is represented as:

[0154]

[0155] In the above formula, Indicates the first The filter used by each transmitting PRI This indicates the conjugate transpose. This indicates the first JRC-CWG signal in each group. One transmitted waveform.

[0156] Subproblem 2 is represented as:

[0157]

[0158] In the above formula, Indicates the first The filter used by each transmitting PRI This indicates the conjugate transpose. This indicates the first JRC-CWG signal in each group. One transmitted waveform;

[0159] The optimal solution to subproblem one is obtained by using the KKT algorithm, and the optimal solution to subproblem two is obtained by using the MM algorithm.

[0160] The optimal solution is:

[0161] Formula (10)

[0162] In formula (10), It is a diagonal loading term that guarantees the invertibility of the matrix;

[0163] , , , ;

[0164] Subproblem 2 is equivalent to:

[0165]

[0166] The second optimal solution is calculated using the MM algorithm. ;

[0167] when When the algorithm terminates, output Otherwise ;

[0168] According to the output Adjust the constraint parameters of the JRC-CWG-RF model to obtain a filter that fits the JRC-CWG-RF model.

[0169] More specifically, step four, the AO-KKT-MM algorithm, solves the optimization problem; it includes the following sub-steps:

[0170] The optimization problem can be rewritten using the penalty function method as follows:

[0171]

[0172] In the formula , Indicates the penalty factor.

[0173] Step 4.1: Set the algorithm termination threshold Based on the idea of ​​alternating optimization, the above equation can be broken down into two subproblems for alternating iterative solutions. Subproblem one after the breakdown is expressed as:

[0174]

[0175] Subproblem 2 can be represented as:

[0176]

[0177] Step 4.2: Solve the subproblem based on the KKT algorithm subproblems It can be rewritten as:

[0178]

[0179] In the formula ,

[0180] , ,

[0181] , .

[0182] Using the KKT algorithm, the optimal solution satisfies the following KKT conditions:

[0183]

[0184]

[0185] In the formula Represents the Lagrange multipliers. Represent the Lagrange function,

[0186] .

[0187] The optimal solution to the problem is:

[0188]

[0189] In the formula It is a diagonal loading term that guarantees the invertibility of the matrix.

[0190] Step 4.3: Solve the subproblem based on the MM algorithm subproblems It can be rewritten as:

[0191]

[0192] in ,and , These are vectors composed of all OWs and RCWs in JRC-CWG, respectively.

[0193] ,and

[0194]

[0195] It is a convolution matrix.

[0196] Step 4.3.1: Transforming the cost function yields:

[0197]

[0198] in , They are respectively , .

[0199] Step 4.3.2: For , By dividing the data into blocks, we can obtain:

[0200]

[0201] in for The former OK List, for The former OK List, for After OK List, for After OK Column, and have ; for The former OK, for After OK.

[0202] Furthermore, we can obtain:

[0203]

[0204] in , This is a constant term.

[0205] After removing the constant term, the optimization problem is equivalent to:

[0206]

[0207] Step 4.3.3: Calculate using the MM algorithm .

[0208] Step 4.4: When When the algorithm terminates, output Otherwise .

[0209] Furthermore, embodiments of the present invention also provide a joint filter design system for a radar communication system and a receiver, comprising: a construction unit, an optimization unit, and a processing unit;

[0210] The construction unit constructs the working scenario of the radar-communication integrated system and the filter of the JRC-CWG-RF model; the construction unit also constructs the optimization problem according to the optimization criteria of the optimization unit;

[0211] When the target and the integrated system are in relative motion in the working scenario, the optimization unit is designed based on the sidelobe performance of the radar receiver filter output of the radar communication integrated system.

[0212] The processing unit uses the AO-KKT-MM algorithm to solve the optimization problem, adjusts the constraint parameters of the JRC-CWG-RF model, and obtains a filter that is adapted to the JRC-CWG-RF model.

[0213] To verify the effectiveness of the radar-communication integrated complementary waveform group and receiver joint filter design provided in the embodiments of the present invention, simulation verification is used to illustrate the beneficial effects of the embodiments of the present invention.

[0214] To evaluate the performance of the designed JRC-CWG-RF model, its radar performance and communication performance were simulated and analyzed.

[0215] 1) Radar performance simulation of the JRC-CWG-RF model

[0216] Let the total number of waveforms in each JRC-CWG group be The integrated system radar receiver input interference plus noise power The value is 10dB, and the interference signal is an OFDM signal. To compare and analyze the sidelobe performance of the CCCF of the JRC-CWG-RF model in this embodiment of the invention, simulations were performed. CCCF of different LFM-BPSK waveforms and their matched filters, and A different traditional BPSK waveform with the corresponding CCCF of the variable mismatch filter (TMF).

[0217] Figure 3 The CCCF of the JRC-CWG-RF model with the number of Open Hours was demonstrated. The changes, including the designed JRC-CWG-RF constraint PAPR constraint (i.e., constant modulus constraint). It can be seen that, when other parameters are the same, the sidelobe level of the CCCF of the JRC-CWG-RF model will increase with... The increase leads to a decrease. When When the number of degrees of freedom is increased, the JRC-CWG-RF model has more degrees of freedom to suppress the sidelobes of its CCCF. Meanwhile, the sidelobes of the CCCF of the JRC-CWG-RF model are consistently lower than the output sidelobes of LFM-BPSK and TMF.

[0218] Figure 4 The CCCF of the JRC-CWG-RF model was demonstrated. constraint The changes in the number of Open Works (OWs) in the JRC-CWG-RF model of this embodiment of the invention. , It can be seen that the CCCF of JRC-CWG-RF varies. The increase leads to a decrease. The increase in implies enhanced interference suppression performance of the JRC-CWG-RF model, which will lead to a decrease in its sidelobe performance.

[0219] Figure 5 This invention demonstrates the PAPR constraint of the CCCF of the JRC-CWG-RF model with respect to OW in an embodiment of the present invention. The changes, including those of JRC-CWG-RF , This shows that as the PAPR of the transmitted waveform increases, the CCCF sidelobe level of JRC-CWG-RF decreases. This conclusion is consistent with expectations, because an increase in PAPR means that the OW value of JRC-CWG-RF is more flexible, potentially leading to solutions with lower sidelobe levels. It can be seen that compared to LFM-BPSK waveforms and TMF, the JRC-CWG-RF model in this embodiment of the invention has lower CCCF sidelobes, which can effectively improve the detection probability of weak targets in multi-target scenarios.

[0220] Depend on Figure 6 It can be seen that when At that time, only and At the specified time, the CCCF sidelobes of the JRC-CWG-RF model were -118.3 dB. In other cases, the CCCF sidelobes of the JRC-CWG-RF model in this embodiment of the invention were all around -150 dB, mainly due to limitations in computer accuracy; the PSLR could not decrease further when it dropped to around -150 dB. Furthermore, the PSLR of the CCCF of the JRC-CWG-RF model in this embodiment of the invention varies with... It rises with the increase, when When the value is increased to 24 dB, the PSLR of CCCF for all JRC-CWG-RF models rises to approximately -20 dB. Therefore, it can be concluded that when... When the value is too large, it will lead to poor sidelobe performance of the CCCF in the JRC-CWG-RF model. Meanwhile, when... and When they are the same, as As the value increases, the PSLR of the CCCF in the JRC-CWG-RF model decreases. Additionally, when... and They are the same. As the number of CCCFs increases, the PSLR of the JRC-CWG-RF model decreases.

[0221] make , Figure 7 The PSLR and PAPR constraints of the CCCF of the JRC-CWG-RF model were simulated. The trade-off curve, when As the price increases, the PSLR of the JRC-CWG-RF model decreases; specifically, as the price increases... From 0dB to 4dB, when At that time, PSLR dropped from -33.1dB to -37.9dB. At that time, PSLR dropped from 38.6dB to -48.0dB. At that time, PSLR dropped from -51.8dB to -93.4dB. It can be seen that when... At that time, the PSLR of the CCCF of the JRC-CWG-RF model varies with The upward and downward trends are more pronounced, while when At that time, PSLR followed The upward and downward trends are the slowest. Based on the above analysis, we can conclude that, with... The PSLR of the CCCF of the JRC-CWG-RF model increases with... The increase and decrease are even faster. Furthermore, from Figure 7 It can be seen that the output PSLR of the JRC-CWG-RF model is always lower than that of the LFM-BPSK and TMF models.

[0222] When the maximum target speed is 40 m / s, let the set of speeds to be optimized be... . Figure 8 This demonstrates the variation of PSLR of CCCF in JRC-CWG-RF with relative motion velocity and different weight vectors. The relationship, among which , , The PSLR of the CCCF in the JRC-CWG-RF is -156.5dB, lower than the PSLR of the other filter outputs; however, when At that time, its PSLR rose to -22.1 dB. Furthermore, when The PSLR of the CCCF of LFM-BPSK is -24.4dB, and that of TMF is -21.8dB. (Using weighted averages...) Compared to LFM-BPSK and TMF, JRC-CWG-RF has advantages in target velocity. The sidelobe performance is not advantageous. (Adoption rights) At that time, At that time, the PSLR of the CCCF of JRC-CWG-RF was -112.8dB. At that time, its PSLR was -40.7dB; using weight ,when At that time, the PSLR of the CCCF of JRC-CWG-RF was -59.4dB. At that time, its PSLR was -46.4dB. It can be seen that when improving the desired optimization speed set... With the corresponding weights, the PSLR of CCCF at zero velocity in JRC-CWG-RF will increase, but the radial velocity of the target and the integrated platform will also increase. The PSLR of CCCF in JRC-CWG-RF will decrease. Figure 9 This demonstrates the variation of PSLR with relative motion velocity and the effect of non-PAPR constraint. The relationship, in which JRCCWG-RF adopts rights , , As can be seen, with other parameters being the same, when When the number of sidelobes is increased, the sidelobe performance of JRC-CWG-RF is improved, which is due to when When the range is increased, the JRC-CWG-RF transmit waveform has a wider range of values, which can yield a better performance solution; Figure 10 This demonstrates the variation of PSLR with relative motion velocity and different The relationship, among which , , It can be seen that, with other parameters being equal, the PSLR of the CCCF of JRC-CWG-RF varies with... The increase leads to a decrease, when With the addition of more degrees of freedom, the integrated system has more options for sidelobe suppression, thus resulting in better sidelobe performance. As the number of sidelobes increases, the communication rate of the integrated system will decrease. In practice, it is necessary to comprehensively consider the communication rate and sidelobe performance of the integrated system when making the selection. . Figure 11 The PSLR curve as a function of Doppler is shown, along with different... The relationship, among which , , As ε0 increases, the interference suppression capability of the JRC-CWG-RF improves, but the sidelobe performance decreases. In summary, when designing the JRC-CWG-RF, different constraint parameters can be adjusted to obtain JRC-CWG-RFs with varying performance.

[0223] 2) JRC-CWG-RF communication performance simulation.

[0224] Since the JRC-CWG-RF transmitted waveform consists of two parts: the optimized waveform OW and the radar communication waveform RCW, where RCW carries communication information and is not optimized, the communication rate of the JRC-CWG-RF model in this embodiment is related to the proportion of RCW to the total number of transmitted waveforms. When the proportion of RCW increases, the communication rate of the JRC-CWG-RF model increases. However, an increase in the proportion of RCW means a decrease in the proportion of OW. Based on the previous conclusion, a decrease in OW may lead to a decline in the sidelobe performance of the JRC-CWG-RF. Therefore, it is necessary to analyze the relationship between the sidelobe performance and the communication rate of the JRC-CWG-RF model. Consider the following simulation parameters: the number of waveforms in each JRC-CWG-RF model is... The power of interference plus noise input to the radar receiver It is 10dB. constraints PAPR constraint Each RCW is [length] PRI pulse is Using 16-PSK waveform modulation RCW, the communication rate of the JRC-CWG-RF model can be expressed as: Consider the set of desired optimization speeds used as follows: and The situation.

[0225] Figure 12 This demonstrates the relationship between the PSLR of the CCCF in the JRC-CWG-RF model and the communication rate when the target velocity is 0 m / s. The PSLR of CCCF is around -150dB when the communication rate is less than or equal to 3.4Mbps. This is mainly due to the limitation of computer precision; the PSLR can only drop to around -150dB. However, when the communication rate is greater than 3.4Mbps, The PSLR of the CCCF rapidly increased to -37.9 dB, indicating that when the communication rate is less than 3.4 Mbps, changing the communication rate of the JRC-CWG-RF model has little impact on its sidelobe performance. When the target speed is 0 m / s, its PSLR increases with the increase of the communication rate. When the communication rate is 0.85 Mbps, its PSLR is -75 dB, while when the communication rate increases to 4.3 Mbps, its PSLR increases to -36.9 dB. Figure 13This paper demonstrates the relationship between the PSLR of the CCCF of the JRC-CWG-RF model and the communication rate when the target velocity is 20 m / s. It shows that when the target velocity is 20 m / s, the PSLR of the CCCF of the JRC-CWG-RF model does not change significantly with the communication rate. This is because the JRC-CWG-RF model does not optimize for the Doppler effect in the target echo. However, for the JRC-CWG-RF model, when the target velocity is 20 m / s, its PSLR increases with the communication rate. When the communication rate is 0.85 Mbps, the PSLR is -30.5 dB, while when the communication rate increases to 4.3 Mbps, the PSLR increases to -25.8 dB.

[0226] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

[0227] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0228] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for designing a joint filter for a radar communication system and receiver, characterized in that, include: A working scenario for an integrated radar-communication system and a filter for a JRC-CWG-RF model are constructed. The receiver of the integrated communication system receives signals emitted by the JRC-CWG-RF model. The transmitter of the integrated communication system transmits JRC-CWG signals to detect weak and strong targets within the scenario, while simultaneously transmitting communication information. The filter output of the JRC-CWG-RF model has a low sidelobe level to prevent the echo signals from weak targets in the working scenario from being overwhelmed by the sidelobes of the echo signals from strong targets. The transmitted JRC-CWG signals and their receiving filters are jointly designed to achieve target detection, communication information transmission, and suppression of interference signals simultaneously. When the target and the integrated system move relative to each other in the working scenario, the sidelobe performance of the radar receiver filter output of the integrated radar communication system is designed and optimized according to the following criteria: when the target and the integrated system move relative to each other in the working scenario, the sidelobe performance of the radar receiver filter output of the integrated radar communication system is designed and optimized according to the following criteria: the sidelobe performance of the radar receiver filter output of the integrated system is optimized by using a template matching method when there is a relative motion velocity between the target and the integrated system. Constructing an optimization problem according to the optimization criterion; wherein, constructing the optimization problem according to the optimization criterion includes: constructing the optimization problem according to the following formula (8) optimization criterion, Formula (8) In formula (8), , Indicates the constraint improvement factor. express The minimum value, This indicates that the power of each transmitted waveform is constrained. Indicates the constraint PAPR. This indicates the maximum acceptable waveform PAPR value for the transmitter of the integrated system. Constrain the peak value of the main lobe output of the receiver filter; This indicates the first JRC-CWG signal in each group. One transmitted waveform, Indicates the first The filter used by each transmitting PRI; The optimization problem is solved using the AO-KKT-MM algorithm. By adjusting the constraint parameters of the JRC-CWG-RF model, a filter adapted to the JRC-CWG-RF model is obtained.

2. The method for designing a joint filter for a radar communication system and receiver according to claim 1, characterized in that, The signal received by the receiver of the integrated communication system from the JRC-CWG-RF model is represented as follows: Official (1) In formula (1), , indicating the first of each group of JRC-CWG signals One transmitted waveform, contained in a set of JRC-CWGs One transmitted waveform, front The waveform is the optimized waveform (OW), then... The waveforms are radar communication waveforms (RCW), and have ; Indicates transpose. For the number of samples, This indicates the Doppler frequency shift caused by the relative motion between the target and the integrated platform. Represents the complex scattering coefficients, which include path loss and the target's RCS. This represents the vector of Gaussian white noise received by the radar receiver of the integrated system, with a mean of 0 and a variance of . , Indicates the first The total interference signal within each transmitting PRI, and the interference signals within different transmitting PRIs are uncorrelated; In the communication integrated system, the receiver receives the signal emitted by the JRC-CWG-RF model. The receiver then... The signal echo within each transmitted PRI is processed by the filter described above. Summing the filter output information within each transmitting PRI, we obtain formula (2): Official (2) In formula (2), Indicates normalized Doppler. Indicates by The convolution matrix formed by the waveform. , Indicates the first The total interference signal within each transmitting PRI, and the interference signals within different transmitting PRIs are uncorrelated; This represents the Gaussian white noise vector output by the filter; In the joint design of the transmitted JRC-CWG signal and its receiving filter, the complementary cross-correlation function between the transmitted JRC-CWG signal and the filter is expressed as follows: Official (3) In formula (3), Indicates by The convolution matrix formed by the waveform. Indicates normalized Doppler. Indicates the first The filter used by each transmitting PRI.

3. The method for designing a joint filter for a radar communication system and receiver according to claim 1, characterized in that, The optimization of the sidelobe performance of the radar receiver filter output of the integrated system when there is a relative velocity between the target and the integrated system using the template matching method includes: The receiver input interference plus noise power of the integrated radar and communication system is expressed as follows: Official (4) In formula (4), This indicates the conjugate transpose. Indicates the first The total interference signal within the PRI transmission. This represents the vector of Gaussian white noise received by the radar receiver of the integrated system. The number of samples; The interference plus noise power in the receiver output sidelobe performance of the integrated radar and communication system is expressed as follows: Official (5) In formula (5), This represents the Gaussian white noise vector output by the filter. ; Indicates the first The filter used by each transmitting PRI; waveform The peak-to-average power ratio (PAPR) is expressed as: Official (6) In formula (6), This indicates the first JRC-CWG signal in each group. One transmitted waveform, This indicates the conjugate transpose. The number of samples; waveform The peak-to-average power ratio (PAPR) constraint is expressed as: Official (7) In formula (7), This indicates the maximum acceptable waveform PAPR value for the integrated communication system.

4. The method for designing a joint filter for a radar communication system and receiver according to claim 1, characterized in that, By rewriting the optimization problem using the penalty function method, formula (8) is rewritten as formula (9): Official (9) In formula (9), Indicates the penalty factor. Indicates the constraint improvement factor. , This indicates that the power of each transmitted waveform is constrained. The constraint PAPR is indicated.

5. The method for designing a joint filter for a radar communication system and receiver according to claim 4, characterized in that, The method of solving the optimization problem using the AO-KKT-MM algorithm includes: Set algorithm termination threshold The optimization problem is broken down into subproblem one and subproblem two, where subproblem one is represented as: in, Indicates the first The filter used by the transmitting PRI. This indicates the conjugate transpose. This indicates the first JRC-CWG signal in each group. One transmitted waveform; Subproblem two is represented as follows: in, Indicates the first The filter used by the transmitting PRI. This indicates the conjugate transpose. This indicates the first JRC-CWG signal in each group. One transmitted waveform.

6. The method for designing a joint filter for a radar communication system and receiver according to claim 5, characterized in that, The method of solving the optimization problem using the AO-KKT-MM algorithm includes: The optimal solution to subproblem one is obtained by solving the KKT algorithm, and the optimal solution to subproblem two is obtained by solving the MM algorithm. The optimal solution one is: Official (10) In formula (10), It is a diagonal loading term that guarantees the invertibility of the matrix; ， ， ， ； The second optimal solution is calculated using the MM algorithm. ; when When the algorithm terminates, output Otherwise ; According to the output Adjust the constraint parameters of the JRC-CWG-RF model to obtain a filter that fits the JRC-CWG-RF model.

7. A radar communication system and receiver joint filter design system, used to implement the method as described in any one of claims 1-6, characterized in that, include: Construction unit, optimization unit, and processing unit; The construction unit constructs the working scenario of the radar-communication integrated system and the filter of the JRC-CWG-RF model; the construction unit also constructs an optimization problem according to the optimization criteria of the optimization unit; The optimization unit designs optimization criteria based on the sidelobe performance of the radar receiver filter output of the radar communication integrated system when the target and the integrated system move relative to each other in the working scenario. The processing unit uses the AO-KKT-MM algorithm to solve the optimization problem, adjusts the constraint parameters of the JRC-CWG-RF model, and obtains a filter that fits the JRC-CWG-RF model.

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