A joint design method of block length and beam for short packet communication radar integrated system

Abstract

The present invention discloses a block length and beam joint design method for a short packet communication radar integrated system, taking the maximization of the sum of the achievable rates of all users as the objective function, and establishing a problem model for the block length and beam joint design of a short packet communication radar integrated system under the conditions of satisfying the signal-to-interference-noise ratio of the communication user, the user block length, the radar signal-to-noise ratio and the transmission power constraints. On this basis, by performing a first-order Taylor expansion on the objective function and the radar signal-to-noise ratio constraint, an approximate substitution function is obtained, and then the beamforming design and block length optimization problem model of the short packet communication radar integrated system is updated, and the updated problem model is iteratively solved until convergence. Compared with the prior art, the method of the present invention has significant advantages in terms of the sum of the overall achievable rates of the system while ensuring the radar signal-to-noise ratio performance.

Description

Technical Field

[0001] The invention belongs to a short packet beamforming technology, in particular to a block length and beam joint design method for a short packet communication radar integrated system. Background Art

[0002] Next-generation wireless networks are facing the challenge of supporting emerging applications such as industrial automation, self-driving cars, and mission-critical communications, which have extremely high requirements for the reliability and real-time performance of communication systems. Ultra-reliable low-latency communication (uRLLC) technology, as the key to realizing these applications, is significantly affected by the size of the transmitted data packet. The design of traditional communication systems is mainly based on the Shannon capacity formula, which assumes an extremely low decoding error probability and an extremely long transmission block length. However, in actual uRLLC systems, a large number of terminal devices need to frequently transmit small-scale data, such as industrial control instructions, sensor measurements, etc., and the typical size of these data packets is only 10 to 30 bytes. Due to the use of finite block length transmission, the classic Shannon capacity formula is no longer applicable, and the impact of the decoding error probability becomes non-negligible.

[0003] In addition to the reliability challenge of short packet transmission, the new generation of wireless systems also need to support accurate environmental perception functions. Due to the natural similarities between radar perception and wireless communication in terms of channel characteristics and signal processing, the communication radar integration (DFRC) technology came into being, realizing the organic integration of communication and perception functions. Taking smart cities as an example, the traffic management system needs to have both reliable short packet communication capabilities and accurate environmental perception functions: on the one hand, uRLLC technology is used to ensure the timely transmission of control instructions, and on the other hand, DFRC's perception capabilities are used to monitor traffic conditions in real time, thereby improving the efficiency and safety of traffic management. With the rapid development of application scenarios such as smart transportation and industrial automation, the demand for systems with both reliable short packet communication and high-precision perception capabilities is growing. Summary of the invention

[0004] The present invention proposes a block length and beam joint design method for a short packet communication radar integrated system, which effectively solves the technical problems faced by the short packet communication radar integrated system by comprehensively considering the dual needs of communication and perception.

[0005] The technical solution to achieve the purpose of the present invention is: a block length and beam joint design method for a short packet communication radar integrated system, the specific steps are:

[0006] Step 1: Construct a transmission signal model based on the transmission beam and the number of base station antennas;

[0007] Step 2: Construct a communication transmission model based on finite data packet length and decoding error probability, and calculate the signal-to-noise ratio and achievable rate of the communication user;

[0008] Step 3: Build a radar perception model and calculate the radar signal-to-noise ratio in the target direction;

[0009] Step 4: Based on the transmission signal model, communication transmission model, and radar perception model, a problem model of block length and beam joint design for the short packet communication radar integrated system is constructed;

[0010] Step 5: Introduce an auxiliary variable to represent the lower bound of the signal-to-interference-noise ratio, reconstruct the objective function, and then perform a first-order Taylor expansion of the reconstructed objective function with respect to the auxiliary variable and the set vector of the finite block length of each communication user to obtain a convex approximate substitution function;

[0011] Step 6: Perform a first-order Taylor expansion of the radar signal-to-noise ratio with respect to the transmit beamforming matrix to obtain an approximate replacement function of the radar signal-to-noise ratio in the target direction;

[0012] Step 7: Solve the updated problem model of block length and beam joint design for the short packet communication radar integrated system to obtain the transmit beamforming matrix and the user's block length. If the iteration termination condition is not met, the obtained transmit beamforming matrix and the user's block length are used as the previous iteration value and return to step 5.

[0013] Compared with the prior art, the present invention has the following significant advantages:

[0014] The block length and beam joint design method for the short packet communication radar integrated system proposed in the present invention, by comprehensively considering the beamforming matrix and the block length of each user, significantly improves the overall achievable rate of the system while ensuring the radar signal-to-noise ratio performance, and has significant advantages over the existing technical solutions.

[0015] Other features and advantages of the present invention will be described in the following description, and part of them will become obvious from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0017] Figure 1 It is an integrated short packet communication radar system.

[0018] Figure 2 It is a flow chart of the present invention.

[0019] Figure 3 is the convergence curve of the proposed method.

[0020] Figure 4 The figure is a performance comparison diagram of the sum of achievable rates of the method proposed in the present invention and the benchmark method under different radar signal-to-noise ratio threshold conditions.

[0021] Figure 5 The figure is a performance comparison diagram of the sum of achievable rates of the method proposed in the present invention and the benchmark method under the condition of total block length. DETAILED DESCRIPTION

[0022] It is easy to understand that according to the technical solution of the present invention, without changing the essential spirit of the present invention, a person skilled in the art can imagine various embodiments of the present invention. Therefore, the following specific embodiments and drawings are only exemplary descriptions of the technical solution of the present invention, and should not be regarded as the whole of the present invention or as a limitation or limitation of the technical solution of the present invention. On the contrary, the purpose of providing these embodiments is to enable those skilled in the art to understand the present invention more thoroughly. The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the innovative concept of the present invention.

[0023] like Figure 1 As shown in FIG. 1 , a communication radar integrated base station supporting short packet transmission is equipped with N transmitting antennas. The base station communicates with K single-antenna users at the same time and senses T targets.

[0024] like Figure 2 As shown in FIG. 1 , a block length and beam joint design method for a short packet communication radar integrated system is provided, and the specific steps are as follows:

[0025] Step 1: Construct a transmission signal model. The transmission signal model is as follows:

[0026]

[0027] In the formula, represents the transmit beamforming matrix, Indicates The transmit beamforming vector of each user, N represents the number of base station antennas, Indicates the number of communication users. represents the total transmitted signal, which satisfies and , It is Data of each user, Except for Data outside the user.

[0028] Step 2: Construct a communication transmission model and calculate the signal-to-noise ratio and achievable rate of the communication user;

[0029] Step 2.1: Build a communication channel, The communication channels for each user are:

[0030]

[0031] In the formula, Indicates the number of base station antennas, For the base station and The number of multipaths between users, Indicates User The gain coefficient of the channel path. It is The user leaves the array at an angle and transmits the steering vector, expressed as

[0032]

[0033] formula, is the carrier wavelength, is the distance between adjacent transmitting antennas, Indicates User The departure angle of the path.

[0034] Step 2.2: Build The received signal of the user is The received signal of a user is specifically:

[0035]

[0036] In the formula, For the The communication channel for each user, Indicates the transmission signal. Indicates The user is interfered by additive white Gaussian noise.

[0037] Step 2.3: The signal-to-interference-noise ratio of a user is:

[0038]

[0039] In the formula, For the The communication channel for each user, Indicates The transmit beamforming vector of each user is, Indicates that except The remaining transmit beamforming vectors outside the user, represents the number of base station antennas, and K represents the number of communication users. Represents the variance of the communication additive white Gaussian noise.

[0040] Step 2.4: In finite block length and decoding error probability Next, The achievable rate for each user is:

[0041]

[0042] In the formula, For the The block length of each user, For the The signal-to-interference-noise ratio of each user is is the inverse function of the Gaussian Q function, where the Gaussian Q function is defined as: . It is expressed as:

[0043]

[0044] In the formula, For the The signal-to-interference-noise ratio of a user.

[0045] Step 3: Build a radar perception model and calculate the radar signal-to-noise ratio in the target direction;

[0046] Step 3.1: Consider T radar targets and construct the echo signal of the tth target, specifically:

[0047]

[0048] In the formula, represents the radar cross section of the t-th target, represents the variance of the radar cross section of the t-th target, represents the transmit beamforming matrix, represents the total transmitted signal, represents the additive white Gaussian noise interference vector, represents the variance of radar additive white Gaussian noise. represents the transmitting array steering vector in the direction of the tth target, specifically:

[0049]

[0050] In the formula, is the carrier wavelength, is the distance between adjacent transmitting antennas, represents the direction of the t-th target.

[0051] Step 3.2: The radar signal-to-noise ratio of the tth target is:

[0052]

[0053] In the formula, represents the transmit beamforming matrix, represents the equivalent radar channel of the t-th target, represents the transmitting array steering vector in the direction of the t-th target, represents the direction of the t-th target, represents the variance of the radar cross section of the t-th target, represents the variance of radar additive white Gaussian noise.

[0054] Step 4: Based on the transmission signal model, communication transmission model, and radar perception model, a problem model of block length and beam joint design for the short packet communication radar integrated system is constructed;

[0055] Combined beamforming design and block length optimization maximizes the sum of the achievable rates of K users while satisfying the communication user SINR, user block length, radar signal-to-noise ratio, and transmission power constraints. Specifically:

[0056]

[0057] In the formula, represents the transmit beamforming matrix, A set vector representing the finite block length of each communication user. For the The signal-to-interference-noise ratio of each user is is the inverse function of the Gaussian Q function, represents the decoding error probability, Specifically . Indicates The signal-to-interference-noise ratio threshold of each user. represents the sum of the lengths of all communication user blocks, Indicates the user minimum block length threshold. Indicates The equivalent radar channel of a target, Indicates The transmitting array steering vector in the direction of the target, Indicates The direction of the goal, Indicates The variance of the radar cross section of the target, represents the variance of radar additive white Gaussian noise, Indicates radar target signal-to-noise ratio threshold, Indicates the transmit power.

[0058] Step 5: Randomly initialize the transmit beamforming matrix and the set vector of the finite block length of each communication user , introduce auxiliary variables Represents the lower bound of the signal-to-interference-noise ratio, reconstructs the objective function, and then performs the reconstructed objective function on and The first-order Taylor expansion of , gives a convex approximate replacement function:

[0059] Step 5.1: Introducing auxiliary variables Represents the lower bound of the signal-to-interference-noise ratio, and reconstructs the objective function, specifically:

[0060]

[0061] In the formula, is the inverse function of the Gaussian Q function, represents the decoding error probability, represents the lower bound of the signal-to-interference-noise ratio, Specifically , represents the signal-to-interference-noise ratio of the kth user The lower bound of Indicates The block length for each user.

[0062] Step 5.2: Reconstruct the target function and The first-order Taylor expansion of , we get a convex approximate replacement function, specifically:

[0063]

[0064] In the formula, is the inverse function of the Gaussian Q function, represents the decoding error probability, represents the signal-to-interference-noise ratio of the kth user The lower bound of Indicates The block length of each user, Specifically . and Respectively and The value of the previous iteration. If it is the i=1th iteration, it is randomly initialized . Specifically:

[0065]

[0066] In the formula, Represents the signal-to-interference-noise ratio of the kth user The lower bound of express The value from the previous iteration.

[0067] Step 5.3: Import As the upper bound of the denominator of the signal-to-noise ratio, SINR constraint for each user Translates to:

[0068]

[0069] In the formula, For the The communication channel for each user, Indicates The transmit beamforming vector of each user is, Indicates that except The remaining transmit beamforming vectors outside the user. and Respectively represent The lower bound of the signal-to-interference-noise ratio of each user and the upper bound of the denominator of the signal-to-interference-noise ratio are: represents the variance of the communication additive white Gaussian noise, Indicates If it is the i=1th iteration, then randomly initialize .

[0070] Step 5.4: The imaginary part of is converted to:

[0071]

[0072] In the formula, For the The communication channel for each user, Indicates The transmit beamforming vector of each user is, and Respectively represent The lower bound of the signal-to-interference-noise ratio of each user and the upper bound of the denominator of the signal-to-interference-noise ratio are calculated.

[0073] Due to constraints The right side is about and is a jointly concave function in the non-negative domain, so about and The first-order Taylor expansion of , we get a convex approximate replacement function, specifically:

[0074]

[0075] In the formula, and Respectively represent The lower bound of the signal-to-interference-noise ratio of each user and the upper bound of the denominator of the signal-to-interference-noise ratio are calculated. and Respectively and The value from the previous iteration.

[0076] Step 6: Compare the radar signal-to-noise ratio with the transmit beamforming matrix The first-order Taylor expansion is used to obtain an approximate replacement function for the radar signal-to-noise ratio in the target direction. The approximate function of is:

[0077]

[0078] In the formula, represents the transmit beamforming matrix, Indicates The equivalent radar channel of a target, Indicates The transmitting array steering vector in the direction of the target, Indicates direction of a goal.

[0079] Step 7: Solve the updated problem model of block length and beam joint design for the short packet communication radar integrated system to obtain the transmit beamforming matrix and the user's block length.

[0080] Step 7.1: Based on steps 5 and 6, construct a new problem model of block length and beam joint design for short packet communication radar integrated system, specifically:

[0081]

[0082] In the formula, represents the transmit beamforming matrix, represents the set vector of finite block lengths of each communication user, represents the lower bound of the signal-to-interference-noise ratio, Represents the upper bound of the denominator of the signal-to-interference-noise ratio. For the The communication channel for each user, Indicates The transmit beamforming vector of each user is, Indicates that except The remaining transmit beamforming vectors outside the user. Indicates The signal-to-interference-noise ratio threshold of each user is Indicates The variance of the radar cross section of the target, Represents the variance of the communication additive white Gaussian noise. represents the sum of the lengths of all communication user blocks, Indicates the user minimum block length threshold. represents the variance of radar additive white Gaussian noise, Indicates radar target signal-to-noise ratio threshold, Indicates the transmit power. express The value of the previous iteration, Indicates The equivalent radar channel of a target, Indicates The transmitting array steering vector in the direction of the target, Indicates direction of a goal.

[0083] Step 7.2: Use convex optimization techniques to solve the problem of joint design of block length and beam for the short packet communication radar integrated system in the i-th iteration. Suboptimization , , and As Iteration , , and .

[0084] When The sum of the achievable rates With Sum of sub-achievable rates The absolute value difference is less than the given tolerance , then the iteration converges and the transmit beamforming matrix is ​​output and a collection vector of finite block length , otherwise return to step 5.1, where and denote the signal-to-interference-noise ratio of the kth user at the i+1th and ith times, respectively. and They represent the short packet lengths of the k-th user at the i+1th and i-th times respectively.

[0085] Example 1

[0086] The present invention is mainly verified by computer simulation method, and all steps and conclusions are verified to be correct on MATLAB-R2021a.

[0087] 1) Initialization of system related parameters

[0088] In the simulation, the number of base station transmitting antennas is , target number , target direction , the variance of radar additive white Gaussian noise dBm, variance of radar cross section of the tth target Using a typical distance-dependent path loss model, the distance between the base station and the target is evenly distributed between 30 meters and 70 meters, the path loss coefficient between the base station and the target is set to 2.2, and the radar signal-to-noise ratio threshold in all directions is the same ( ). The number of paths between the base station and the kth user , the gain coefficient of the kth user's lth path , the variance of the communication additive white Gaussian noise dBm, set the user signal-to-noise ratio threshold to , user minimum block length threshold bits. In addition, considering the equal block length between users ( ) as a baseline method.

[0089] 2) Method performance simulation analysis

[0090] Figure 3 The convergence curve of the proposed method is shown in Figure 1. The proposed method has a convergence behavior under different radars, where the number of users is and total block length It is obvious that the proposed method converges very quickly and becomes stable at the 15th iteration, which proves the effectiveness of the proposed method. Figure 4 The performance comparison of the sum of the achievable rates of the proposed method and the benchmark method under different radar signal-to-noise ratio threshold conditions is shown, where the total block length bits. Figure 4 It can be seen that as the radar signal-to-noise ratio threshold The sum of the achievable rates increases, and the sum of the achievable rates decreases. This is because the short packet communication radar integrated system gradually tends to the radar function, and the proposed method has a good balance between radar and communication functions. The sum of the achievable rates of the proposed method is better than that of the baseline method, which is because the proposed algorithm flexibly allocates the short packet block length between users. Figure 5 The performance comparison of the sum of the achievable rates of the proposed method and the benchmark method under the condition of total block length is shown, where the radar signal-to-noise ratio threshold dB. Figure 5 As can be seen from As the total block length increases, the sum of the achievable rates of the proposed method also increases. This is because When is large, the influence of the decoding error probability on the sum of achievable rates can be approximately ignored. When there are many users, the sum of achievable rates of the proposed method is more obvious than that of the benchmark method. This is because in the case of multiple users, the proposed method of the present invention more flexibly optimizes the length of each user block, thereby achieving a better sum of achievable rates performance.

[0091] The above description is only a preferred specific implementation of the present invention, but the protection scope of the present invention is not limited thereto.

[0092] Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the protection scope of the present invention.

[0093] It should be understood that in order to simplify the present invention and help those skilled in the art understand the various aspects of the present invention, in the above description of the exemplary embodiments of the present invention, the various features of the present invention are sometimes described in a single embodiment or described with reference to a single figure. However, the present invention should not be interpreted as the features included in the exemplary embodiments are all necessary technical features of the patent claims.

[0094] It should be understood that the modules, units, components, etc. included in the device of an embodiment of the present invention can be adaptively changed to be set in a device different from the embodiment. The different modules, units, or components included in the device of the embodiment can be combined into one module, unit, or component, or they can be divided into multiple sub-modules, sub-units, or sub-components.

Claims

1. A block length and beam joint design method for a short packet communication radar integrated system, characterized in that: The specific steps are: Step 1: Construct a transmission signal model based on the transmission beam and the number of base station antennas; Step 2: Construct a communication transmission model based on finite data packet length and decoding error probability, and calculate the signal-to-noise ratio and achievable rate of the communication user; Step 3: Build a radar perception model and calculate the radar signal-to-noise ratio in the target direction; Step 4: Based on the transmission signal model, communication transmission model, and radar perception model, a problem model for the joint design of block length and beam for the short packet communication radar integrated system is constructed. The specific method is as follows: Joint beamforming design and block length optimization are used to maximize the sum of the achievable rates of K users while satisfying the communication user SINR, user block length, radar signal-to-noise ratio, and transmission power constraints. The specific problem model is: ， In the formula, represents the transmit beamforming matrix, represents the set vector of finite block lengths of each communication user, is the signal-to-interference-noise ratio of the kth user, is the inverse function of the Gaussian Q function, represents the decoding error probability, Specifically , represents the signal-to-interference-noise ratio threshold of the kth user, represents the sum of the lengths of all communication user blocks, Indicates the user minimum block length threshold, represents the equivalent radar channel of the t-th target, represents the transmitting array steering vector in the direction of the t-th target, represents the direction of the t-th target, represents the variance of the radar cross section of the t-th target, represents the variance of radar additive white Gaussian noise, represents the signal-to-noise ratio threshold of the t-th radar target, Indicates the transmit power; Step 5: Introduce an auxiliary variable to represent the lower bound of the signal-to-interference-noise ratio, reconstruct the objective function, and then perform a first-order Taylor expansion of the reconstructed objective function with respect to the auxiliary variable and the set vector of the finite block length of each communication user to obtain a convex approximate substitution function; Step 6: Perform a first-order Taylor expansion of the radar signal-to-noise ratio with respect to the transmit beamforming matrix to obtain an approximate replacement function of the radar signal-to-noise ratio in the target direction; Step 7: Solve the updated problem model of block length and beam joint design for the short packet communication radar integrated system to obtain the transmit beamforming matrix and the user's block length. If the iteration termination condition is not met, the obtained transmit beamforming matrix and the user's block length are used as the previous iteration value and return to step 5.

2. The block length and beam joint design method for the short packet communication radar integrated system according to claim 1 is characterized in that: The specific transmission signal model is: ， In the formula, represents the transmit beamforming matrix, Represents the total transmitted signal, satisfying and , It is Data of each user, express The conjugate of Except for Data outside the user, express The conjugate of represents mathematical expectation.

3. The block length and beam joint design method for the short packet communication radar integrated system according to claim 1 is characterized in that: The specific method of constructing a communication transmission model based on finite data packet length and decoding error probability and calculating the signal-to-noise ratio and achievable rate of the communication user is as follows: Step 2.1: Construct a communication channel. The communication channel of the kth user is as follows: ， In the formula, is the number of multipaths between the base station and the kth user, represents the gain coefficient of the lth channel path of the kth user, is the departure angle transmitting array steering vector of the kth user; Step 2.2: Construct the received signal of the kth user, specifically: ， In the formula, is the communication channel of the kth user, Indicates the transmission signal. represents the additive Gaussian white noise interference to the kth user; Step 2.3: Calculate the signal-to-interference-noise ratio of the kth user, specifically: ， In the formula, is the communication channel of the kth user, represents the transmit beamforming vector of the kth user, represents the transmit beamforming vectors of the remaining users except the kth user, and K represents the number of communication users; Step 2.4: In finite block length and decoding error probability Under this condition, the achievable rate of the kth user is calculated as follows: ， In the formula, is the block length of the kth user, is the signal-to-interference-noise ratio of the kth user, is the inverse function of the Gaussian Q function, It is expressed as: ， In the formula, is the signal to interference and noise ratio of the kth user.

4. The block length and beam joint design method for the short packet communication radar integrated system according to claim 1 is characterized in that: Build a radar perception model and calculate the radar signal-to-noise ratio in the target direction: Step 3.1: Construct the echo signal of the tth target, specifically: ， In the formula, represents the radar cross section of the t-th target, represents the variance of the radar cross section of the t-th target, represents the transmit beamforming matrix, represents the total transmitted signal, represents the additive white Gaussian noise interference vector, represents the variance of radar additive white Gaussian noise, represents the transmitting array steering vector in the direction of the t-th target, T is the total number of radar targets, represents the direction of the t-th target; Step 3.2: Calculate the radar signal-to-noise ratio of the tth target, specifically: ， In the formula, represents the equivalent radar channel of the tth target.

5. The block length and beam joint design method for the short packet communication radar integrated system according to claim 1 is characterized in that: An auxiliary variable is introduced to represent the lower bound of the signal-to-interference-noise ratio, and the objective function is reconstructed. Then, the reconstructed objective function is subjected to a first-order Taylor expansion of the set vector of the auxiliary variable and the finite block length of each communication user to obtain a convex approximate substitution function. The specific process is as follows: Step 5.1: Introducing auxiliary variables Represents the lower bound of the signal-to-interference-noise ratio, and reconstructs the objective function, specifically: ， In the formula, is the inverse function of the Gaussian Q function, represents the decoding error probability, represents the lower bound of the signal-to-interference-noise ratio, Specifically , It is expressed as the lower bound of the signal-to-interference-noise ratio of the kth user, represents the block length of the kth user; Step 5.2: Perform a first-order Taylor expansion of the reconstructed objective function with respect to the set vector of the finite block length of each communication user and the auxiliary variables to obtain a convex approximate substitution function, specifically: In the formula, is the inverse function of the Gaussian Q function, represents the decoding error probability, and Respectively and The value of the previous iteration; Specifically: ， Step 5.3: Import As the upper bound of the denominator of the signal-to-noise ratio, the signal-to-noise ratio constraint of the kth user is Translates to: . In the formula, is the communication channel of the kth user, represents the transmit beamforming vector of the kth user, represents the transmit beamforming vectors of the remaining users except the kth user, represents the upper bound of the denominator of the signal-to-interference-to-noise ratio of the kth user, represents the variance of the communication additive white Gaussian noise, represents the signal-to-interference-noise ratio threshold of the kth user; Step 5.4: The imaginary part of is converted to: ， In the formula, is the communication channel of the kth user, represents the transmit beamforming vector of the kth user, represents the imaginary part of a complex number, and They represent the lower bound of the signal-to-interference-plus-noise ratio and the upper bound of the denominator of the signal-to-interference-plus-noise ratio of the kth user respectively; Due to constraints The right side is about and is a jointly concave function in the non-negative domain, so About and The first-order Taylor expansion of , we get a convex approximate replacement function, specifically: 。 6. The block length and beam joint design method for the short packet communication radar integrated system according to claim 5 is characterized in that: Radar signal-to-noise ratio is calculated based on the transmit beamforming matrix The first-order Taylor expansion gives the radar signal-to-noise ratio approximate substitution function in the target direction, The approximate function of is: ， In the formula, represents the transmit beamforming matrix, represents the equivalent radar channel of the t-th target, represents the transmitting array steering vector in the direction of the t-th target, represents the direction of the t-th target.

7. The block length and beam joint design method for the short packet communication radar integrated system according to claim 6 is characterized in that: Solve the updated problem model of block length and beam joint design for short packet communication radar integrated system, and obtain the transmit beamforming matrix and user block length, which is: Step 7.1: Based on steps 5 and 6, construct a new problem model for joint design of block length and beam for short packet communication radar integrated system, specifically: In the formula, represents the set vector of finite block lengths of each communication user, represents the variance of the radar cross section of the t-th target, represents the sum of the lengths of all communication user blocks, Indicates the user minimum block length threshold, represents the variance of radar additive white Gaussian noise, represents the signal-to-noise ratio threshold of the t-th radar target, Indicates the transmit power. express The value of the previous iteration; Step 7.2: Use convex optimization technology to solve the problem of block length and beam joint design for the short packet communication radar integrated system for the i-th iteration, and optimize the i-th optimization to obtain , , and As i+1 iterations , , and ; When the absolute difference between the sum of the achievable rates at the i-th time and the sum of the achievable rates at the i-1th time is less than the given tolerance , then the iteration converges and the transmit beamforming matrix is ​​output and a collection vector of finite block length , otherwise return to step 5.1.

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