A resource allocation method for terahertz communication and perception integrated network

Abstract

The present invention provides a resource allocation method for a terahertz communication and perception integrated network. The method includes setting performance requirement parameters for the terahertz communication and perception integrated network; extracting current network state parameters, terahertz signal transmission parameters, and extracted frame structure parameters; calculating a frequency domain sampling interval and a time domain sampling interval based on the performance requirement parameters and the frame structure parameters; then calculating a minimum perception overhead and an allocation method of perception resources in the time domain and the frequency domain, including a frequency domain sampling interval, a time domain sampling interval, and a ratio of perception time domain resources to frequency domain resources to form a perception allocation scheme; and after completing resource configuration based on the minimum perception overhead and the perception allocation scheme, testing the quality of a received signal at a user terminal under the current real-time resource configuration to determine whether it meets the requirements. If not, adjusting the network state parameters and terahertz signal transmission parameters, updating the perception overhead and the perception allocation scheme, and reconfiguring the resources. If yes, maintaining the current resource configuration.

Description

Technical Field

[0001] The present invention belongs to wireless communication technology, and in particular relates to a resource allocation technology applicable to a terahertz communication and perception integrated wireless network. Background Art

[0002] 6G networks are expected to support exponentially growing data capacity and digital twin applications that go beyond communications with virtual experiences. The currently widely used microwave frequency bands below 6 GHz cannot provide sufficient spectrum resources. In addition, emerging application scenarios such as the Internet of Vehicles, digital twins, and virtual reality require communication systems to have the ability to transmit large amounts of data and detect and perceive the environment. Therefore, wireless communications are developing towards higher undeveloped frequency bands. Terahertz communication technology generally refers to technology that uses 0.1 THz-10 THz frequency band signal communication. Compared with traditional microwave communications, the terahertz frequency band has an ultra-large available bandwidth and a shorter wavelength, so terahertz signals have both high-speed data transmission capabilities and high-precision perception capabilities. Therefore, terahertz communication networks can integrate communication and perception functions into one, that is, terahertz communication and perception integration (ISAC) technology. However, the application of terahertz networks with integrated communication and perception functions has the following technical problems:

[0003] 1) The ultra-short wavelength of terahertz causes large propagation loss and obvious absorption effect of atmospheric molecules in its signal transmission, and the signal is easily blocked by obstacles, namely the line-of-sight (LoS) blocking effect, which limits the transmission distance of terahertz signals.

[0004] 2) Transceivers typically use highly directional antennas to increase the antenna gain provided by receiving terahertz signals. However, extremely narrow beams present challenges in network beam management, including frequent beam switching and severe beam misalignment. This leads to link interruptions and limits terahertz network coverage. Therefore, effective ISAC-assisted networking strategies need to be developed to enhance communication coverage.

[0005] 3) There is resource competition between the communication and perception functions in the terahertz ISAC network. To balance the performance of communication and perception functions, an effective resource allocation scheme needs to be developed to achieve high-performance and low-overhead terahertz networks. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for allocating communication and perception resources in the time domain and frequency domain for a terahertz network having an ISAC (communication and perception integrated network), which can improve the coverage probability of the terahertz network.

[0007] The technical solution adopted by the present invention to solve the above technical problems is a resource allocation method for a terahertz communication and sensing integrated network, comprising the steps of:

[0008] Initialization step: setting the performance requirement parameters for the terahertz communication and perception integrated network;

[0009] Parameter extraction step: extracting the current network state parameters, terahertz signal transmission parameters and frame structure parameters;

[0010] The steps for generating the sensing overhead and sensing allocation scheme are as follows: the frequency domain sampling interval and the time domain sampling interval are calculated based on the performance requirement parameters and the frame structure parameters; the minimum sensing overhead is then calculated based on the detected mobile speed of the user terminal currently establishing a communication connection with the base station, the frame structure parameters, the current network status parameters, the frequency domain sampling interval, and the time domain sampling interval; finally, the ratio of sensing time domain resources to frequency domain resources is determined based on the minimum sensing overhead, the frequency domain sampling interval, the time domain sampling interval, and the extracted frame structure parameters; the frequency domain sampling interval, the time domain sampling interval, and the ratio of sensing time domain resources to frequency domain resources form the sensing allocation scheme;

[0011] Resource configuration step: The number of symbols N occupied by the perception signal in the time domain is calculated based on the minimum perception overhead and the ratio of perception time domain resources to frequency domain resources. s and the number of occupied symbols N in the frequency domain f , in the time domain, N is performed according to the time domain sampling interval s The sampling of the perceptual signal of symbols is performed in the frequency domain according to the frequency domain sampling interval N f Sampling of the perception signal of the number of subcarriers;

[0012] Test steps: Test the user terminal's received signal quality under the current real-time resource configuration, and calculate the maximum coverage distance of the current user terminal based on the received signal quality, terahertz signal transmission parameters, and performance requirement parameters;

[0013] Judgment step: Determine whether the maximum coverage distance can meet the requirements. If not, adjust the network state parameters and terahertz signal transmission parameters, update the perception overhead and perception allocation plan, and reconfigure resources. If yes, maintain the current resource configuration.

[0014] The present invention is based on the ability of perception-assisted terahertz narrow beam management, and through high-performance resource allocation, it improves terahertz link connection performance, reduces network interference, and thus maximizes network coverage performance.

[0015] Specifically, the performance parameters required for the integrated terahertz communication and perception network include the perceptual measurable distance d max , Perceived measurable speed v max , communication signal-to-interference-and-noise ratio threshold SINR T, Communication coverage probability threshold and terahertz signal transmission distance r qos ;

[0016] Current network status parameters, including the density λ of base stations, mobile users, and obstacles in the network B ,λ M ,λ S , the number of beams used by the base station n b and beamwidth θ b , the number of beams used by the user end n m and beamwidth θ m ;

[0017] Terahertz signal transmission parameters, including the transmitted signal power P T and atmospheric molecule absorption noise coefficient K;

[0018] Extract frame structure parameters, including center frequency f c , symbol length T sym , subcarrier spacing f scs , synchronization signal block sending interval τ.

[0019] Accordingly, the specific method for calculating the frequency domain interpolation interval U and the time domain interpolation interval V according to the performance requirement parameters and the frame structure parameters is as follows:

[0020]

[0021] represents rounding down, and c represents the speed of light.

[0022] The minimum perception overhead is calculated based on the detected mobile speed v of the user terminal currently establishing a communication connection with the base station, the frame structure parameters, the current network status parameters, the frequency domain sampling interval U and the time domain sampling interval V. The specific method is:

[0023]

[0024] Among them, the median

[0025] Median λ=λ B +λ M +λ S , v is the mobile speed of the user end, ln represents the natural logarithm function, and the intermediate values ​​c1 and c2 are:

[0026]

[0027]

[0028] r is the integral term variable, and e is a natural constant.

[0029] Based on the least perceived overhead The frequency domain interpolation interval U, the time domain interpolation interval V and the extracted frame structure parameters are used to obtain the ratio of perceived time domain resources to frequency domain resources α opt The specific method is:

[0030]

[0031] Based on the minimum perceived cost The ratio of perceived time domain resources to frequency domain resources α opt Calculate the number of symbols N occupied by the signal in the time domain s and the number of occupied symbols N in the frequency domain f The specific method is:

[0032]

[0033] The quality of the user-side received signal under the current real-time resource configuration is determined by the interference power I received by the user side. s and noise power P N Extract the interference power I received by the node s , noise power P N , terahertz signal transmission parameters and performance requirement parameters to calculate the maximum coverage distance r of the user end max The specific method is:

[0034]

[0035] in,

[0036] Specifically, in the judgment step, adjusting the network state parameters and terahertz signal transmission parameters is as follows: increasing the base station transmission power P T and using a narrower beamwidth θ b .

[0037] The beneficial effects of the present invention are:

[0038] (1) In order to improve the coverage probability of the ISAC-based terahertz network, the present invention provides a communication and perception time-frequency resource allocation scheme that can simultaneously meet the communication coverage probability requirements and the perception measurable range requirements, and minimize the overhead required for perception-assisted communication.

[0039] (2) Based on the current 5G communication network standard, the present invention designs the optimal number of resource grids occupied by the perception signal, the sampling interval of the comb perception signal, and the ratio of the perception time domain resources to the frequency domain resources.

[0040] (3) The resource allocation scheme provided by the present invention can effectively reduce the overhead required for sensing-assisted terahertz signal beam alignment, reduce the communication signal transmission bandwidth and time occupied by sensing, and increase the terahertz communication throughput while ensuring the stability of the terahertz link.

[0041] (4) The solution provided by the present invention is highly flexible and can be adjusted based on network node density, user mobility, and the selected transmission signal bandwidth. The technical solution of the present invention is highly compatible with existing wireless communication networks and requires only minor adjustments to the currently used parameter set, making it highly practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a flow chart of the sensing resource allocation solution of the present invention.

[0043] Figure 2 This is a flow chart for obtaining the current network status and service demand status for the present invention.

[0044] Figure 3 Schematic diagram of the ISAC signal frame structure designed for the present invention.

[0045] Figure 4 This is a graph showing the change in the minimum number of sensing resource grids required under different sensing signal time-frequency resource ratios.

[0046] Figure 5 This is the curve showing the minimum number of sensing resource grids required to meet terahertz network coverage requirements under different time-frequency resource allocation ratios.

[0047] Figure 6 This is a comparison chart of the maximum coverage distances obtained by using the solution of the present invention and not using the solution of the present invention. DETAILED DESCRIPTION

[0048] The present invention is described in detail below with reference to the accompanying drawings and simulation examples, and the practicability of the present invention is demonstrated.

[0049] The present invention is applicable to a terahertz wireless mobile communication network with an ISAC, which can use the sensing function to provide assistance for terahertz communication beam alignment, thereby improving the coverage probability of the terahertz network. In order to solve the problem of competition between communication and sensing resources, the present invention provides a time-frequency allocation scheme and a comb-shaped sensing signal pattern that minimizes the resources occupied by the sensing function. Specifically, the present invention considers a network composed of multiple randomly distributed base stations. There are multiple users moving in random directions in the network, and the uniformly distributed user speeds are considered. The terahertz communication node includes a base station and a user terminal. In addition to the terahertz communication node, the present invention also considers the problem of obstacles blocking the communication signal, and considers the presence of multiple randomly distributed obstacles in the network. The resource allocation scheme proposed in the present invention can effectively improve the network communication coverage probability and the sensing measurable range, and minimize the sensing resource overhead required to meet business needs. The time-frequency signal structure proposed in the present invention is based on the current 5G communication system orthogonal frequency division multiplexing (OFDM) frame structure and parameter set design, has high practicality, and can be integrated into the existing system. As Figure 1 As shown, the specific implementation plan of the communication and perception resource allocation scheme proposed in the present invention is as follows:

[0050] Step S1: Set the communication and sensing requirements of the terahertz ISAC service: 1) Sensing the measurable distance d max ; 2) Perceived measurable speed v max ;3) Communication Signal-to-Interference-plus-Noise Ratio (SINR) threshold SINR T ; 4) Communication coverage probability threshold 5) Terahertz signal transmission distance r qos .

[0051] Step S2 specifically includes the following sub-steps: Figure 2 As shown, the details are as follows:

[0052] Step S210: The network parameters to be extracted include: 1) the density of nodes in the network, i.e. the density of base stations, mobile users and obstacles λ B ,λ M ,λ S ; 2) The number of beams used by the terahertz communication node, that is, the number of beams used at the base station and the user end respectively n b ,n m , base station beam width θ b , user beamwidth θ m .

[0053] Step S220: THz signal parameters to be extracted: 1) Transmitted signal power P T ;2) Atmospheric molecule absorption noise coefficient K;.

[0054] Step S230: Frame structure related parameters: center frequency f c , symbol length T sym , subcarrier spacing f scs , the synchronization signal block sending interval τ.

[0055] like Figure 3 As shown in FIG, the time-frequency resource grid defines the unit of time-frequency resource allocation as a resource grid. A resource grid occupies one symbol in the time domain and one subcarrier in the frequency domain.

[0056] Step S3 specifically includes the following sub-steps: Figure 4 As shown, the details are as follows:

[0057] Step S310: Calculate the optimal comb-shaped perception signal frequency domain sampling interval U and time domain sampling interval V. The perception signal in the time domain and frequency domain sampling interval limits the perceptual measurable interval. The frequency domain sampling interval U is selected to satisfy the perceptual measurable coverage distance d. max The maximum integer required, the frequency domain sampling interval U is:

[0058]

[0059] in is a floor function, and c represents the speed of light.

[0060] The time domain sampling interval V is selected to meet the requirement of perceptual measurable speed d max The maximum integer of the time domain sampling interval V is

[0061]

[0062] Step S320: According to the center frequency f of the transmission signal c , subcarrier spacing f scs , Symbol duration T sym , Communication transmission distance requirement r qos and coverage probability requirements Total allocation Resource grids give perception signals:

[0063]

[0064]

[0065] Node density in the network λ = λ B +λ M +λ S , parameters c1, c2 are:

[0066]

[0067]

[0068] Step S330: Determine the ratio of the total sensing resource grid allocation in the time domain and frequency domain. Define the ratio of the number of sensing resources occupied in the time domain unit (number of symbols) to the number of frequency domain units (number of subcarriers). c , subcarrier spacing f scs , Symbol duration T sym , the allocation ratio of sensing resources in the time-frequency domain is α opt for:

[0069]

[0070] Step S4: According to the allocation scheme obtained in S3, configure the communication and perception signal frame structure. The specific signal occupies the number of symbols in the time domain The number of subcarriers occupied in the frequency domain is Interval U sampling.

[0071] Step S5: Extract the interference power I received by the user terminal communication node currently connected to the base station s and noise power P N According to the service SINR receiving threshold requirement SINR T , calculate the maximum coverage distance r of the node max .

[0072]

[0073] in

[0074] Step S6: Determine whether the coverage distance meets the terahertz communication transmission distance requirement r max ≥r qos If the maximum coverage distance cannot meet the requirements, return to step S2 and the base station increases the transmission power P T , the base station selects a narrower beam width θ b , recalculate the communication and sensing resource allocation scheme.

[0075] The implementation entity of the above steps is the base station in the network. The judgment and adjustment are completed by the base station. The base station can instruct the user to make adjustments, but the adjustment decision is made at the base station end.

[0076] This paper further illustrates the effectiveness of the proposed communication and perception resource allocation scheme, as well as how its configuration changes with system parameters. By comparing the network coverage and perception overhead of a system without the proposed scheme, it demonstrates that the proposed scheme can provide significant performance gains.

[0077] Figure 5 This figure shows the minimum number of sensing resource grids required to meet terahertz network coverage requirements at different time-frequency resource allocation ratios. The resource grids required to achieve the required allocation ratio using this solution are marked with red dots. Compared to using an allocation ratio that deviates 10% from the optimal ratio, the optimal resource allocation ratio reduces sensing overhead by approximately 40%-50%.

[0078] Figure 6 The following figure compares the maximum coverage distances achieved with and without the proposed scheme. Using this scheme, the coverage range is approximately twice that of the non-sensing case. Compared with the ideal sensing case, the proposed scheme can effectively utilize limited sensing resources to achieve a coverage distance close to the ideal one.

[0079] In summary, the present invention provides a communication and sensing time-frequency resource allocation scheme for terahertz networks with ISACs, aiming to improve the coverage probability of terahertz networks. This scheme utilizes sensing capabilities to assist in terahertz narrow beam management in ISAC networks. It designs the minimum sensing resource usage, sensing signal time-frequency ratio, and comb sensing signal sampling interval to maximize coverage probability. This scheme significantly reduces the sensing overhead required to meet communication coverage requirements and, based on the current protocol frame structure, demonstrates practicality.

Claims

1. A resource allocation method for a terahertz communication and perception integrated network, characterized in that: Including steps: Initialization step: setting the performance requirement parameters for the terahertz communication and perception integrated network; Parameter extraction step: extracting the current network state parameters, terahertz signal transmission parameters and frame structure parameters; The steps for generating the sensing overhead and sensing allocation scheme are as follows: the frequency domain sampling interval and the time domain sampling interval are calculated based on the performance requirement parameters and the frame structure parameters; the minimum sensing overhead is then calculated based on the detected mobile speed of the user terminal currently establishing a communication connection with the base station, the frame structure parameters, the current network status parameters, the frequency domain sampling interval, and the time domain sampling interval; finally, the ratio of sensing time domain resources to frequency domain resources is determined based on the minimum sensing overhead, the frequency domain sampling interval, the time domain sampling interval, and the extracted frame structure parameters; the frequency domain sampling interval, the time domain sampling interval, and the ratio of sensing time domain resources to frequency domain resources form the sensing allocation scheme; Resource configuration step: Calculate the number of symbols N occupied by the sensing signal in the time domain based on the minimum sensing overhead and the proportion of sensing resources in the time domain and frequency domain. s and the number of occupied symbols N in the frequency domain f , in the time domain, N is performed according to the time domain sampling interval s The sampling of the perceptual signal of symbols is performed in the frequency domain according to the frequency domain sampling interval N f Sampling of the perception signal of the number of subcarriers; Test steps: Test the user terminal's received signal quality under the current real-time resource configuration, and calculate the maximum coverage distance of the current user terminal based on the received signal quality, terahertz signal transmission parameters, and performance requirement parameters; Judgment step: Determine whether the maximum coverage distance can meet the requirements. If not, adjust the network state parameters and terahertz signal transmission parameters, update the perception overhead and perception allocation plan, and reconfigure resources. If yes, maintain the current resource configuration.

2. The method according to claim 1, wherein: The performance requirement parameters for the terahertz communication sensing integrated network include the sensing measurable distance d max , Perceived measurable speed v max , communication signal-to-interference-and-noise ratio threshold SINR T , Communication coverage probability threshold and terahertz signal transmission distance r qos ; The current network state parameters include the density λ of base stations, mobile users and obstacles in the network B ,λ M ,λ S , the number of beams used by the base station n b and beamwidth θ b , the number of beams used by the user end n m and beamwidth θ m ; The terahertz signal transmission parameters include the transmission signal power P T and atmospheric molecule absorption noise coefficient K; The extracted frame structure parameters include the center frequency f c , symbol length T sym , subcarrier spacing f scs , synchronization signal block sending interval τ.

3. The method according to claim 2, wherein: The specific method for calculating the frequency domain sampling interval U and the time domain sampling interval V based on the performance requirement parameters and frame structure parameters is: represents rounding down, and c represents the speed of light.

4. The method according to claim 2, wherein: The minimum perception overhead is calculated based on the detected mobile speed v of the user terminal currently establishing a communication connection with the base station, the frame structure parameters, the current network status parameters, the frequency domain sampling interval U and the time domain sampling interval V. The specific method is: Among them, c represents the speed of light, the intermediate value Median λ=λ B +λ M +λ S , v is the mobile speed of the user end, ln represents the natural logarithm function, and the intermediate values ​​c1 and c2 are: r is the integral term variable, and e is a natural constant.

5. The method according to claim 4, wherein: Based on the least perceived overhead The frequency domain interpolation interval U, the time domain interpolation interval V and the extracted frame structure parameters are used to obtain the ratio of perceived time domain resources to frequency domain resources α opt The specific method is:

6. The method according to claim 2, wherein: Based on the minimum perceived cost The ratio of perceived time domain resources to frequency domain resources α opt Calculate the number of symbols N occupied by the perception signal in the time domain s and the number of occupied symbols N in the frequency domain f The specific method is:

7. The method according to claim 2, wherein: The quality of the user terminal receiving signal under the current resource real-time configuration is determined by the interference power I received by the user terminal. s and noise power P N To reflect.

8. The method according to claim 7, wherein: Extract the interference power I of the user end s , noise power P N , terahertz signal transmission parameters and performance requirement parameters to calculate the maximum coverage distance r of the user end max : in, c represents the speed of light.

9. The method according to claim 2, wherein: The maximum coverage distance meets the requirement to determine whether r max ≥r qos If so, the demand is met; otherwise, the demand is not met.

10. The method according to claim 2, wherein: In the judgment step, the network state parameters and terahertz signal transmission parameters are adjusted as follows: increasing the base station transmission power P T and using a narrower base station beamwidth θ b , and enter the resource configuration step to reconfigure the minimum sensing resource overhead, frequency domain sampling interval, time domain sampling interval and the ratio of sensing time domain resources to frequency domain resources.

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