A resource allocation method for a radar communication integrated security system

Abstract

The application provides a resource allocation method for an OFDM-based radar communication integrated system, wherein a subcarrier allocation vector is initialized according to the calculation of the signal-to-noise ratios of a detection channel, a communication channel and an eavesdropping channel on a subcarrier; the optimal solution of a radar subcarrier allocation vector and a power allocation vector of a communication subcarrier is calculated according to the current subcarrier allocation vector; and the subcarrier allocation vector, the optimal solution of the radar subcarrier allocation vector and the power allocation vector of the communication subcarrier are iteratively optimized to output a final resource allocation scheme. The radar communication integrated device transmits information to a receiver, detects parameters such as the distance from a target from a return signal, and prevents information leakage to the target. Physical layer security technology is adopted, and the optimal transmission beam of the DFRC device maximizes the system security rate on the premise of ensuring the target estimation rate.

Description

Technical Field

[0001] This invention relates to radar-communication integration technology, and particularly to resource allocation technology for radar-communication integrated security systems. Background Technology

[0002] Radar-communication integration combines communication and radar functions into the same hardware and software, with both functions implemented simultaneously using the same waveform. The purpose of a radar-communication integrated system is to transmit information to a receiver while simultaneously detecting parameters such as distance to the target from the echo signal. Radar-communication integration technology significantly reduces the payload weight of combat units such as ships and aircraft, and also reduces the electromagnetic scattering area, increasing the difficulty of enemy detection. The integration of radar and communication systems also reduces economic costs and power consumption. Therefore, radar-communication integration has a very promising application prospect in the military field.

[0003] The radar-communication integrated system based on Orthogonal Frequency Division Multiplexing (OFDM) uses OFDM waveforms to simultaneously detect targets and send communication data to legitimate users. Since the channel conditions of each subcarrier in the OFDM system are different in radar detection and communication, the subcarriers need to be allocated reasonably. Otherwise, it may lead to the inability to achieve target detection and secure communication functions, and will also increase power consumption. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for realizing the integrated function of radar communication while ensuring the minimum mutual information content and communication security rate of radar.

[0005] The technical solution adopted by this invention to solve the above-mentioned technical problems is a resource allocation method for an OFDM-based integrated radar and communication system, comprising the following steps:

[0006] Step 1: Set the total number of subcarriers N of the integrated radar communication DFRC device. s The maximum power P of the signal on the k-th subcarrier max,k Input probe channel frequency response vector H rad Communication channel frequency response vector H com and the target channel frequency response vector H eve The variance of Gaussian random noise in the input detection channel, communication channel, and eavesdropping target channel. and

[0007] Step 2: Calculate the signal-to-noise ratio β of the probe channel on the k-th subcarrier. r,k , The signal-to-noise ratio α of the communication channel on the k-th subcarrierb,k , The signal-to-noise ratio α of the eavesdropping channel on the k-th subcarrier e,k , Among them, H rad [k]、H com [k]、H eve [k] is divided into H rad H com H eve The k-th element;

[0008] Step 3: Initialize the subcarrier allocation vector u: When the signal-to-noise ratio (SNR) of the communication channel on the k-th subcarrier is greater than the SNR of the eavesdropping channel, set the k-th element u in the subcarrier allocation vector u. k A value of 1 indicates that the k-th subcarrier is allocated for communication functions; otherwise, u is set to 1. k A value of -1 indicates that the k-th subcarrier is allocated for radar function use; the first Lagrange multiplier γ and the second Lagrange multiplier ζ are set.

[0009] Step 4: Based on the current subcarrier allocation vector, calculate the radar subcarrier power allocation vector and the communication subcarrier power allocation vector:

[0010]

[0011]

[0012] in, The k-th element of the radar subcarrier power allocation vector. θ is the k-th element of the power allocation vector for the communication subcarrier. r,k Assign variables to the radar of the k-th subcarrier. When θ r,k =1 indicates that the k-th subcarrier is used for radar purposes, when θ r,k =0 indicates that the k-th subcarrier is not used for radar purposes; θ c,k Assign variables for communication of the k-th subcarrier. When θ c,k =1 indicates that the k-th subcarrier is used for secure communication purposes, when θ c,k =0 indicates that the k-th subcarrier is not used for secure communication purposes;

[0013] Then, by projecting the radar subcarrier power allocation vector and the communication subcarrier power allocation vector, the optimal solution for the radar subcarrier power allocation vector and the communication subcarrier power allocation vector is obtained:

[0014]

[0015]

[0016] in, The k-th element of the optimal solution for the radar subcarrier power allocation vector. This is the k-th element of the optimal solution for the power allocation vector of the communication subcarrier. The k-th element of the radar subcarrier power allocation vector. This is the k-th element of the power allocation vector for the communication subcarrier. For the interval [0, P] max,k Projection onto ];

[0017] Step 5: Determine the optimal solution x of the radar subcarrier power allocation vector obtained in Step 4. ＊ The optimal solution y of the power allocation vector of the communication subcarrier ＊ Does the requirement meet? If yes, proceed to step 6; otherwise, return to step 4 after updating γ and ζ.

[0018] Step 6: Add the index k of the subcarriers allocated to the communication function to the index set, and then select the optimal solution according to the power allocation vector of the communication subcarriers. The subcarriers are arranged in descending order of their allocated power, the initial iteration count is l = 1, and u is set. l =u,(x ＊ ) l =x ＊ ,(y ＊ ) l =y ＊ ,P min =P l =∑((x) ＊ ) l +(y ＊ ) l ), u l P l 、(x ＊ ) l and (y) ＊ ) l Let P represent the optimal solutions for the subcarrier allocation vector, total allocated power, and power allocation vector of the radar subcarrier and the communication subcarrier, respectively, in the l-th iteration. min Minimum power allocation;

[0019] Step 7: Let k l Given the index of the l-th element in the index set, first use u from the l-th iteration. l For u l+1 Assign a value, then update u l+1 The kth l Each element is -1;

[0020] Step 8: Put ul+1 Substituting the current subcarrier allocation vector into step 4, we obtain (x) ＊ ) l+1 ,(y ＊ ) l+1 Determine whether the condition is met. If so, then by setting u l+1 The kth l Update u with each element set to 1 l+1 Proceed to step 9; otherwise, let P min =P l+1 Proceed to step 9;

[0021] Step 9: Determine the k-th l If the element is the last element of the index set, and if not, update l = l + 1 and return to step 7; if yes, when P l+1 ≥P min At that time, output the subcarrier allocation vector u for the (l+1)th iteration. l+1 The power allocation vector of the radar subcarrier and the power allocation vector of the communication subcarrier in the l-th iteration (x ＊ ) l ,(y ＊ ) l As the final resource allocation scheme; when P min =P l+1 At that time, output the subcarrier allocation vector u for the (l+1)th iteration. l+1 The power allocation vector of the radar subcarrier and the power allocation vector of the communication subcarrier in the (l+1)th iteration (x ＊ ) l+1 ,(y ＊ ) l+1 As the final resource allocation scheme.

[0022] The system includes an integrated radar-communication DFRC device, a legitimate receiver, and an eavesdropping target. The DFRC device transmits information to the receiver while simultaneously detecting parameters such as distance to the target from the echo signal, and preventing information leakage to the target. Employing physical layer security technology, the DFRC device uses its optimal transmission beam to maximize system security rate while ensuring target estimation rate.

[0023] The beneficial effect of this invention is that, while ensuring the minimum mutual information content and communication security rate of the radar, it aims to minimize the total system power by adopting resource joint allocation technology to achieve integrated radar communication functions. Attached Figure Description

[0024] Figure 1 For application scenarios;

[0025] Figure 2 This is a flowchart of an implementation example;

[0026] Figure 3 A comparison of the total power and running time obtained by different methods under different radar minimum mutual information thresholds and communication security rate limits;

[0027] Figure 4 For n=2, τ r =T rad =18nats,τ c =T s Resource allocation of the Basic algorithm when =18 nats / s;

[0028] Figure 5 For n=2, τ r =T rad =18nats,τ c =T s Resource allocation in the Greedy algorithm when the speed is 18 nats / s;

[0029] Figure 6 For n=2, τ r =T rad =18nats,τ c =T s Resource allocation of the BB algorithm when =18 nats / s. Detailed Implementation

[0030] Implementation examples and application scenarios are as follows Figure 1 As shown:

[0031] Assume a dual-function radar communication (DFRC) device within an integrated radar communication security system, along with a legitimate confidential information receiver B and a radar target E (also acting as an eavesdropper). In this scenario, the DFRC device needs to detect the target and transmit information to the legitimate receiver while ensuring that the information is not eavesdropped on by the detected target. Assume the integrated transceiver uses OFDM waveforms to simultaneously detect the target and transmit communication data to the legitimate user. The system bandwidth is divided into N... s There are N subcarriers. Let N be the number of subcarriers in the system. s The set consisting of orthogonal subcarriers is The integrated OFDM waveform Y model is as follows:

[0032] Y = F H (πr-(I-π)c)

[0033] Among them, F H Represents the Inverse Discrete Fourier Transform (IDFT) matrix; vector Represents frequency domain radar symbols; vector Represents frequency domain communication symbols; I represents the identity matrix; π = diag{π[0],π[1],...,π[N]} s π[k] is the subcarrier allocation matrix, which is a diagonal matrix whose diagonal elements are taken from a binary set. If the k-th subcarrier is used for radar purposes, then π[k] = 1; if the k-th subcarrier is used for secure communication purposes, then π[k] = 0.

[0034] Assume the transmitted radar and communication symbols r and c are determined. Furthermore, assume that the impulse responses of the detection, communication, and eavesdropping channels are all generalized stationary Gaussian processes with known second-order statistics. Then, the received signal S at the integrated transceiver, at the communication user, and at the eavesdropping target... rad S com and S eve They can be represented as:

[0035] S rad =YH rad +w

[0036] S com =YH com +v

[0037] S eve =YH eve +e

[0038] in, and Let w, v, and e represent the frequency response vectors of the detection channel, communication channel, and eavesdropping target channel, respectively; w, v, and e are zero-mean covariance matrices, respectively. and Gaussian random noise vector and The variance of Gaussian random noise for the detection channel, communication channel, and eavesdropping target channel.

[0039] The mutual information between the echo signal received by the integrated transceiver and the impulse response of the detection channel is used as an indicator of radar performance. Based on the signal model considered, we can write the mutual information I of the integrated communication-radar system. rad ,as follows:

[0040]

[0041] Among them, H rad [k] is H rad The k-th element is the probe channel frequency response on the k-th subcarrier; |X[k]| 2 This represents the transmit power of the OFDM waveform allocated to the k-th subcarrier. Note that... It can be viewed as the signal-to-noise ratio (SNR) of the probe channel on the k-th subcarrier.

[0042] On the other hand, the downlink communication link and the eavesdropping link of the target are modeled using Shannon capacity. Therefore, the information rate of the legitimate communication user is expressed as the sum of the achievable data rates R on all available subcarriers. com ,Right now:

[0043]

[0044] Among them, R com [k] represents the achievable data rate on the k-th subcarrier; H com [k] is H com The k-th element is the communication channel frequency response on the k-th carrier, and correspondingly, |H com [k]| 2 This represents the power gain of the communication channel. Similarly, the rate at the eavesdropping target on all available subcarriers and R... eve It can be represented as

[0045]

[0046] Among them, R eve [k] represents the data rate at the target location on the k-th subcarrier; H eve [k] is H eve The k-th element in the vector is the frequency response of the eavesdropping channel on the k-th subcarrier, and the corresponding |H eve [k]| 2 This represents the power gain of the eavesdropping channel on the k-th subcarrier. and These are respectively considered as the signal-to-noise ratio (SNR) of the communication channel and the SNR of the eavesdropping channel on the k-th subcarrier. Finally, the security capacity C of the system under the Gaussian white noise channel is... s for:

[0047] C s =max{R com -R eve ,0}.

[0048] The main objective of this invention is to minimize the total transmit power of an integrated communication-radar system by jointly optimizing subcarrier allocation and power allocation, while simultaneously satisfying specified mutual information constraints and security rate constraints for the detection channel. Specifically, the problem under consideration can be expressed in the following form:

[0049]

[0050] stI rad ≥T rad ,

[0051] C s ≥T s ,

[0052]

[0053]

[0054] Among them, T rad The minimum mutual information threshold required; T s P is the lower bound of the required security rate; max [k] represents the maximum transmit power allowed on the k-th subcarrier.

[0055] Now, let β r,k Let α be the signal-to-noise ratio (SNR) of the probe channel on the k-th subcarrier. b,k Let α be the signal-to-noise ratio of the communication channel on the k-th subcarrier. e,k Let S be the signal-to-noise ratio of the eavesdropping channel on the k-th subcarrier. Then the problem can be rewritten as:

[0056]

[0057]

[0058]

[0059]

[0060]

[0061] in, and These are the subcarrier allocation vector and the subcarrier power vector, respectively, satisfying the minimum threshold τ of mutual information. r =T rad The minimum threshold τ that satisfies the secure communication rate c =T s The power p of the kth subcarrier k =|X[k]| 2 The upper limit P of the power of the k-th subcarrier max,k =P max [k].

[0062] This invention uses a greedy algorithm to obtain the optimal solution to the problem under consideration.

[0063] First, initialize the subcarrier allocation vector u and keep it unchanged. Then, solving the original problem becomes solving two subproblems: the power allocation vector x for the radar subcarriers and the power allocation vector y for the communication subcarriers.

[0064]

[0065]

[0066]

[0067] and

[0068]

[0069]

[0070]

[0071] x k and y k Let x and y represent the k-th elements in the power allocation vector x of the radar subcarrier and the power allocation vector y of the communication subcarrier, respectively.

[0072] Solving these two subproblems yields the radar subcarrier power allocation vector and the communication subcarrier power vector. The k-th element of the radar subcarrier power allocation vector is represented as... The k-th element of the power allocation vector for the communication subcarrier is represented as After obtaining the suboptimal solution, update u, then solve the two subproblems to obtain the new suboptimal solution, and repeat this process until convergence.

[0073] To solve the two subproblems, we first compare α b,k and α e,k We obtain the initialized u. Specifically, when α b,k ≥α e,k When, make the k-th element u in the radar subcarrier allocation vector k =1 indicates that the k-th subcarrier is allocated for communication functions; otherwise, u is set to 1. k =-1 indicates that the k-th subcarrier is allocated for radar function use. Next, the first subproblem is rewritten as the Lagrangian function of the first subproblem.

[0074]

[0075] In the first subproblem, the Lagrange multiplier γ≥0.

[0076] By making We can obtain:

[0077]

[0078] Radar allocation variables When θ r,k=1 indicates that the k-th subcarrier is used for radar purposes, when θ r,k When θ = 0, it means that the k-th subcarrier is not used for radar purposes. Solving for θ... r,k ≠0 o'clock:

[0079]

[0080] When θ r,k When = 0, The value of γ can be found in I using a binary search method. rad =τ r It was obtained at that time.

[0081] Similarly, let For the Lagrange function of the second subproblem, and the Lagrange multipliers ζ≥0 of the second subproblem, by making get:

[0082]

[0083] Among them, communication allocation variables When θ c,k =1 indicates that the k-th subcarrier is used for secure communication purposes, when θ c,k When θ = 0, it means that the k-th subcarrier is not used for secure communication. Solving for θ... c,k ≠0 o'clock:

[0084]

[0085] When θ c,k When = 0, The value of the Lagrange multiplier ζ can be obtained in C using a binary search method. s =τ c It was obtained at that time.

[0086] Taking into account the power constraints on each subcarrier, the optimal solutions to the two subproblems are finally obtained. and

[0087]

[0088]

[0089] in It means the projection onto the interval [a,b].

[0090] The implementation process is as follows: Figure 2 The steps shown are as follows:

[0091] Step 1: Input parameters. Input the number of subcarriers N for the DFRC device. s The maximum power P of the signal on each subcarriermax,k Input frequency response vectors of the detection channel, communication channel, and eavesdropping target channel. and Input Gaussian random noise vector and Input radar mutual information threshold τ r =T rad and the lower bound threshold τ of the security rate c =T s .

[0092] Step 2: Calculation

[0093] Step 3: Initialize the subcarrier allocation vector u: When α b,k ≥α e,k When, make u k =1, otherwise make u k = -1. Initialize γ and ζ to appropriate positive numbers.

[0094] Step 4: Based on the current subcarrier allocation vector, solve the two subproblems of the original problem to obtain:

[0095]

[0096]

[0097] The optimal solutions to the two subproblems are obtained after projection:

[0098]

[0099]

[0100] Step 5: Update γ and ζ using a binary search method, and repeat step 4 until I is satisfied. rad =τ r and C s =τ c of and

[0101] Step 6: Let the index set Will Index k in the middle is according to Arrange the elements in descending order, let the iteration count l = 1, and set u... l =u,(x ＊ ) l =x ＊ ,(y ＊ ) l =y ＊ , u l P l 、(x ＊ ) l and (y) ＊ ) l Let P represent the optimal solutions for the subcarrier allocation vector, total allocated power, and power allocation vector of the radar subcarrier and the communication subcarrier, respectively, in the l-th iteration. min This represents the minimum total power allocation.

[0102] Step 7: Let k l for The index of the l-th element is obtained by first using u from the l-th iteration. l For u l+1 Assign a value, then update u l+1 The kth l The element is -1, i.e., u l+1 =u l ,

[0103] Step 8: Put u l+1 Substituting into step 4, we get (x) ＊ ) l+1 ,(y ＊ ) l+1 Determine whether the condition is met. If so, then by setting u l+1 The kth l Update u with each element set to 1 l+1 , Proceed to step 9; if not, let P min =P l+1 Proceed to step 9.

[0104] Step 9: Determine the k-th l Are the elements...? If the last element is not found, update l = l + 1 and return to step 7; if it is found, when P... l+1 ≥P min At that time, output the subcarrier allocation vector u for the (l+1)th iteration. l+1 The power allocation vector of the radar subcarrier and the power allocation vector of the communication subcarrier in the l-th iteration (x ＊ ) l ,(y ＊ ) l As the final resource allocation scheme; when P min =P l+1 At that time, output the subcarrier allocation vector u for the (l+1)th iteration. l+1The power allocation vector of the radar subcarrier and the power allocation vector of the communication subcarrier in the (l+1)th iteration (x ＊ ) l+1 ,(y ＊ ) l+1 As the final resource allocation scheme.

[0105] In the following scenario, the number of OFDM subcarriers in DFRC is N. s =128 / n; Maximum subcarrier power P max,k =200W, Communication channel frequency response vector H com and the frequency response vector H of the eavesdropping channel eve It follows a complex Gaussian distribution with variance of 1 and mean of 0; the radar channel frequency response vector H rad It follows a complex Gaussian distribution with variance of 0.01 and mean of 0; the noise vector variance...

[0106] Figure 3 The Greedy-based algorithm of the embodiment was compared with two other algorithms at different radar minimum mutual information thresholds T. rad and the lower bound of the communication security rate T s The total power obtained is shown below. The Basic algorithm refers to directly calculating the suboptimal solution {u} to the original problem after initializing the subcarrier allocation vector u. ＊ ,p ＊ =(x ＊ +y ＊ That is, steps 1 to 5 in this invention are executed sequentially; the BB algorithm refers to the branch and bound algorithm, a common algorithm for solving integer programming problems, which is implemented in the simulation by calling the BOMIN optimizer. The calculation result of the Basics algorithm can be regarded as the upper bound of the total power, while the result of the BB algorithm can be regarded as the lower bound of the total power. From Figure 1 As can be seen from this, with n remaining constant, as T... rad and T s As the value increases, the total power required gradually increases; at T rad / N s and T s / N s With n remaining constant, as n decreases (i.e., N... s As n increases, the total power calculated by each algorithm also increases accordingly; when n is the same, the total power calculated by the Greedy algorithm is slightly greater than that calculated by the BB algorithm, but significantly less than that calculated by the Basic algorithm.

[0107] Figure 4The proposed Greedy-based algorithm and the BB algorithm were compared under different radar minimum mutual information thresholds T. rad and the lower bound of the communication security rate T s The computation time under T. It can be seen that the computation time of the two algorithms is basically not affected by T. rad and T s It changes with the change of n; as n decreases (i.e., N... s (Increase the value of n) both algorithms have increased computation time; with the same value of n, the computation time of Greedy's algorithm is significantly less than that of BB's algorithm.

[0108] Figure 5 and Figure 6 It shows n=2, τ r =T rad =18nats,τ c =T s When the power is 18 nts / s, the resource allocation results calculated by the three algorithms show that the subcarrier and power allocation results obtained by the Greedy and BB algorithms are relatively close. Compared with the Basic algorithm, the number of subcarriers allocated to communication is reduced and the number of subcarriers allocated to radar is increased. However, the amount of reduction in radar power exceeds the amount of increase in communication power, thus reducing the total power.

[0109] In summary, the performance of the embodiment is close to that of the branch and bound (BB) algorithm and better than that of the Basic algorithm, but the computation speed is faster than that of the BB algorithm.

[0110] In this example, there is an OFDM transceiver A with both communication and radar functions, a legitimate receiver B, and an eavesdropping target E. Transceiver A transmits information to receiver B and simultaneously detects parameters such as distance to target E from the echo signal. The number of transmit subcarriers N of transceiver A is... s =64.

[0111] Assuming the maximum subcarrier power P max,k =200W, Communication channel frequency response vector H com and the frequency response vector H of the eavesdropping channel eve It follows a complex Gaussian distribution with variance of 1 and mean of 0; the radar channel frequency response vector H rad It follows a complex Gaussian distribution with variance of 0.01 and mean of 0; the noise vector variance... Radar mutual information threshold τ r =T rad =18 nats and lower bound of communication security rate τ c =T s = 18 nats / s.

[0112] Next, the following operations will be performed sequentially to complete the joint allocation of resources while ensuring radar mutual information and communication security rate and minimizing total power:

[0113] Step 1: Calculation

[0114] Step 2: Initialize the subcarrier allocation vector u: When α b,k ≥α e,k When, make u k =1, otherwise make u k =-1. Initialize the Lagrange multipliers γ and ζ to appropriate positive numbers.

[0115] Step 3: Keeping u constant, solve the two subproblems of the original problem to obtain:

[0116]

[0117]

[0118] The optimal solutions to the two subproblems are obtained after projection:

[0119]

[0120]

[0121] Step 4: Update γ and ζ using a binary search method, and repeat step 3 until I is satisfied. rad =τ r and C s =τ c of and

[0122] Step 5: Let the index set Will Index k in the middle is according to Arrange in descending order, let l = 1, u l =u,(x ＊ ) l =x ＊ ,(y ＊ ) l =y ＊ ,

[0123] Step 6: Let k l for Let u be the l-th element in the set. l+1 =u l ,

[0124] Step 7: Obtain (x) through steps 3 and 4. ＊ ) l+1 ,(y ＊ ) l+1 ,if Then let Otherwise, let P min =P l+1 If k l no For the last element of P, let l = l + 1, and return to step 6; otherwise, when P min <P l+1 When, output u l+1 , (x ＊ ) l ,(y ＊ ) l When P min =P l+1 When, output u l+1 , (x ＊ ) l+1 ,(y ＊ ) l+1 .

Claims

1. A resource allocation method for an integrated radar and communication security system, characterized in that, Includes the following steps: Step 1: Set the total number of subcarriers for the integrated radar and communication device. , No. The maximum power of the signal on each subcarrier Input the frequency response vectors of the detection channel, communication channel, and eavesdropping target channel; input the Gaussian random noise variances of the detection channel, communication channel, and eavesdropping target channel. Step 2: Calculate the first... The signal-to-noise ratio of the probe channel on the nth subcarrier, the nth The signal-to-noise ratio of the communication channel on the nth subcarrier, the nth Signal-to-noise ratio of the eavesdropping channel on each subcarrier; Step 3: Initialize the subcarrier allocation vector When the first When the signal-to-noise ratio (SNR) of the communication channel on each subcarrier is greater than the SNR of the eavesdropping channel, the subcarrier allocation vector is set. The Middle element A value of 1 indicates the first... Each subcarrier is allocated for communication functions; otherwise, it is set. for , indicating the first Each subcarrier is allocated for radar function use; the first Lagrange multiplier is set. Second Lagrange multiplier ; Step 4: Calculate the radar subcarrier power allocation vector and the communication subcarrier power allocation vector based on the current subcarrier allocation vector; Then, by projecting the elements of the radar subcarrier power allocation vector and the communication subcarrier power allocation vector, we obtain the optimal solutions for the radar subcarrier power allocation vector and the communication subcarrier power allocation vector. in, The optimal solution for radar subcarrier power allocation vector. element The optimal solution for the communication subcarrier power allocation vector. One element, The first step of the radar subcarrier power allocation vector element The first power allocation vector for communication subcarriers One element, In the interval Projection on; Step 5: Determine the optimal solution for the radar subcarrier power allocation vector obtained in Step 4. The optimal solution of the communication subcarrier power allocation vector If the requirements are met, proceed to step 6; otherwise, update using a binary search method. and Then, return to step 4; Step 6: Assigning the sequence number of the subcarrier to the communication function Add to the index set and select the optimal solution according to the power allocation vector of the communication subcarrier. The subcarriers are assigned power values ​​in descending order, and the initial iteration count is determined. ,set up , , , and They represent the first The optimal solutions for the subcarrier allocation vector, total allocated power, and power allocation vector of the radar subcarrier in each iteration, and the optimal solution for the power allocation vector of the communication subcarrier. Minimum total power allocation; Step 7: Set For the first in the index set The index of the nth element is used first. The next iteration right Assign a value, then update The Middle The elements are ; Step 8: [The text appears to be incomplete and contains several grammatical errors. A more accurate translation would require the full context.] Substituting the current subcarrier allocation vector into step 4 yields... Determine whether the condition is met. If so, then by setting The Middle Update when each element is 1. Proceed to step 9; otherwise, let Proceed to step 9; Step 9: Determine the first Check if the element is the last element of the indexed set. If not, update. Return to step 7; if so, when When, output the first Subcarrier allocation vector of the next iteration No. The power allocation vectors for radar subcarriers and communication subcarriers in the next iteration. As the final resource allocation scheme; when When, output the first Subcarrier allocation vector of the next iteration No. The power allocation vectors for radar subcarriers and communication subcarriers in the next iteration. As the final resource allocation plan; The specific method for calculating the radar subcarrier allocation vector and the communication subcarrier power allocation vector based on the current subcarrier allocation vector in step 4 is as follows: in, The first vector assigned to the radar subcarrier element The power allocation vector of the communication subcarrier is the first... One element; For the first Radar allocation variables for each subcarrier, ,when Time indicates the first Subcarriers are used for radar applications, when Time indicates the first Individual subcarriers are not used for radar purposes; For the first Communication allocation variables for each subcarrier, ,when Time indicates the first Subcarriers are used for secure communication purposes, when Time indicates the first Subcarriers are not used for secure communication purposes.

2. The method as described in claim 1, characterized in that, Step 2: Calculate the first... Signal-to-noise ratio of the probe channel on each subcarrier , , No. Signal-to-noise ratio of communication channels on each subcarrier , , No. Signal-to-noise ratio of the eavesdropping channel on each subcarrier , ;in, , , Divided into , , The Middle One element; Let be the input probe channel frequency response vector. This is the frequency response vector of the communication channel. The frequency response vector of the target channel being eavesdropped on; , and These represent the Gaussian random noise variances of the input detection channel, communication channel, and eavesdropping target channel, respectively.

3. The method as described in claim 1, characterized in that, The optimal solution for radar subcarrier allocation vector in step 5 The optimal solution of the power allocation vector of the communication subcarrier Specifically, the requirements are to meet the mutual information requirements of the integrated communication and radar system and the system's security capacity requirements under Gaussian white noise channels.

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