Resource allocation scheme and light guide method for V2V user grouping

Abstract

The invention provides a V2V user grouping resource allocation scheme and a light guide method, and relates to the technical field of wireless communication, and the V2V user grouping resource allocation scheme comprises the following steps: S1, V2V user grouping, S2, resource allocation power control, and S3, multiplexing matching. The resource allocation problem that a plurality of vehicle users multiplex the same cellular user link resource is solved, the communication reliability of the V2V users is represented through the outage probability, the communication quality of the vehicle users is ensured, meanwhile, the maximum total capacity of the cellular users serves as a primary target, and according to the size of interference between the cellular users and different V2V users, the communication reliability of the V2V users is improved. And multiplexing grouping is carried out on a large number of V2V users, and the optimal transmitting power of all the users in the multiplexing group is solved, so that the communication capacity of the cellular users is effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and in particular to a resource allocation scheme and a light guiding method for V2V user grouping. Background Art

[0002] With the synchronous development of the automobile industry and communication technology, vehicles have become mobile information platforms that integrate wireless communication technology, providing people with intelligent driving experience and rich infotainment services. The development and progress of this technology has led to the emergence of Internet of Vehicles technology. Internet of Vehicles is a technology that establishes a communication network between vehicles or between vehicles and road facilities. This technology allows vehicles to communicate with each other during driving and exchange data with road infrastructure, cloud servers, etc. Its core is to improve the safety, efficiency and intelligence of the transportation system.

[0003] In the increasingly busy and densely populated urban traffic environment, vehicle-to-vehicle communication technology, as an innovative technology aimed at improving road safety, traffic efficiency and driving convenience, is gradually coming into people's view. However, with the surge in the number of vehicles and the dense distribution of communication nodes, in the V2V communication system, each vehicle equipped with corresponding communication equipment is regarded as an independent communication node. During driving, these nodes will continuously exchange information with surrounding vehicles, such as key data such as speed, location, and driving intention.

[0004] However, when these vehicles are densely distributed and share limited spectrum resources, they may initiate communication requests at the same time or almost at the same time, resulting in overlap and conflict between signals, which is called "mutual interference". This interference phenomenon will not only cause data transmission delays and increase packet loss rates, but may also hinder the transmission of key information, thereby affecting the accuracy and timeliness of driving decisions. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and provide a resource allocation solution and a light guiding method for V2V user grouping.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: a resource allocation scheme for V2V user grouping, comprising the following steps:

[0007] S1, V2V user grouping. First, construct an interference graph, where the vertex set is defined as V. Each vertex in the vertex set V represents a cellular user or a V2V user. Each edge in the edge set E has a weight, which represents the interference between two vertices.

[0008] S2. Resource allocation power control. In order to ensure the communication quality of V2V users, the interruption probability is used to ensure communication reliability, which can be expressed as follows:

[0009] S3. Multiplexing matching: In order to maximize the overall total capacity of the system, it is necessary to reasonably match the grouped V2V multiplexing groups with the cellular link resources one-to-one.

[0010] As a preferred implementation, in step S1, the specific steps are: the weight of the edge set Represents two vertices V i and V j The potential mutual interference between , defined as the sum of the mutual interference between two vertices, can be expressed as: in, Represents the vertex V i Vertex V j The interference caused Then it means that the vertex V j Vertex V i Due to different reuse conditions, interference It is not a specific value, but an M×M interference matrix. Interference matrix It can be expressed as:

[0011] The technical effect of adopting the above technical solution is: ensuring the communication quality of V2V users during the communication process, avoiding communication failure or information loss due to signal interference, and finally through multiplexing matching, the present invention realizes a one-to-one reasonable matching between the V2V multiplexing group and the cellular link resources, thereby further improving the overall capacity and efficiency of the system.

[0012] As a preferred implementation, in step S1, the specific steps are as follows: the goal of V2V user grouping is to divide the K VUE users in the system into M groups, and the group set is defined as G M ={1,2,…,M}, VUEs that reuse the same cellular link resources are grouped as users. In order to divide VUE users with strong interference into different groups, the grouping target is set as:

[0013] The technical effect of adopting the above technical solution is: by allocating VUE users with strong interference to different groups, direct interference between them is avoided, thereby reducing the interference level of the system and improving the communication quality.

[0014] As a preferred embodiment, in step S1, the specific steps are: min represents the minimum value of the sum of all co-channel interferences in the same group, Represents the sum of all co-channel interference in the same group.

[0015] The technical effect of adopting the above technical solution is that by selecting the minimum value of the sum of all co-channel interferences in the same group as a representative, the mutual interference between channels in the group can be more accurately reflected.

[0016] As a preferred embodiment, in step S2, the specific steps are: represents the minimum SINR required for V2V users to establish a reliable link, p 0 represents the tolerable interruption probability on the physical layer of the V2V link. Combining the maximum transmission power constraints of V2V users and cellular users, the optimal transmission power of cellular users is solved as:

[0017] The technical effect of adopting the above technical solution is: by accurately determining the optimal transmission power of cellular users, it is possible to minimize interference to other communication systems while ensuring that V2V users establish reliable links.

[0018] As a preferred implementation, in step S2, the specific steps are: wherein, α is the large-scale fading component of the communication link, including path loss and shadow fading.

[0019] The technical effect of adopting the above technical solution is that it is possible to accurately quantify the large-scale fading components in the communication link, thereby more accurately evaluating the attenuation of the signal during the transmission process.

[0020] As a preferred implementation, in step S2, the specific steps are: wherein, is a The matrix stores the m-th multiplexing group The optimal transmit power for a VUE user pair. Indicates that the same multiplexing group The channel gain from a VUE transmitting user to a CUE user.

[0021] The technical effect of adopting the above technical solution is that the transmission power of the VUE users in each multiplexing group can be managed and optimized, thereby ensuring that the interference to the CUE users is minimized.

[0022] As a preferred implementation, in step S3, the specific steps are: Substituting the optimal transmission power of CUE and VUE obtained in step 2 into the Shannon formula to obtain the maximum communication capacity of the cellular user, and substituting the maximum capacity Each row of the coefficient matrix is ​​subtracted from its minimum value, and each column of the coefficient matrix after completing the first step is subtracted from its minimum value.

[0023] The technical effect of adopting the above technical solution is that it can achieve balanced processing of communication capacity between different users, avoiding the problem of overall system performance degradation due to high communication demands of individual users.

[0024] As a preferred implementation, in step S3, the specific steps are: using the smallest row and column to cover the elements in the coefficient matrix that are already zero, if the sum of the row and column is n, the algorithm ends, otherwise proceed to the next step.

[0025] The technical effect of adopting the above technical solution is: by minimizing the coverage of rows and columns, the interference with non-zero elements in the coefficient matrix is ​​effectively reduced, thereby improving the efficiency and accuracy of the algorithm.

[0026] As a preferred implementation, in step S3, the specific steps are: find the minimum value among the uncovered elements, subtract the minimum value from all uncovered elements, and add the minimum value to the elements whose rows and columns are covered once, and then return to the previous step.

[0027] The technical effect of adopting the above technical solution is: it can ensure that the algorithm can effectively reduce the maximum value of the uncovered elements in each iteration, thereby accelerating the process of finding a solution.

[0028] Compared with the prior art, the advantages and positive effects of the present invention are:

[0029] The maximum communication capacity of cellular users is calculated by substituting the optimal transmission power of CUE and VUE into the Shannon formula. These maximum communication capacity values ​​are then organized into a coefficient matrix. Each element is evaluated on a uniform scale by subtracting the minimum values ​​in the rows and columns. The system then tries to cover the elements in the matrix that are already zero with the minimum rows and columns. If the sum of the rows and columns meets the predetermined conditions, it means that the current resource allocation scheme is sufficiently optimized and the algorithm ends. However, if the preliminary optimization fails to meet the conditions, the algorithm automatically enters the next step, which is to find the minimum value of the uncovered elements and make corresponding adjustments to all uncovered elements. For elements that are covered once in both rows and columns, the minimum value is added. Through such an iterative process, the system can continuously adjust and optimize the resource allocation plan. With such a design, the system solves the resource allocation problem of multiple vehicle users reusing the same cellular user link resources under dense vehicle conditions. The communication reliability of V2V users is represented by the interruption probability, which ensures the communication quality of vehicle users. At the same time, maximizing the total capacity of cellular users is taken as the primary goal. According to the interference between cellular users and different V2V users, a large number of V2V users are multiplexed and grouped, and the optimal transmission power of all users in the multiplexing group is solved, which effectively improves the communication capacity of cellular users. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure Description

[0031] Figure 1 It is a flow chart of the implementation of the present invention;

[0032] Figure 2 It is a comparison chart of the present invention with the independent resource block power allocation algorithm and the greedy algorithm under different numbers of multiplexed vehicles.

[0033] Figure 3 This is a diagram showing the influence of the cellular user transmission power on the total capacity of the cellular link under different reuse ratios of the present invention.

[0034] Figure 4 This is a diagram showing the influence of the multiplexing ratio on the total capacity of the cellular link under different V2V link signal-to-interference-noise ratio thresholds of the present invention.

[0035] Figure 5 It is a comparison diagram of the present invention, SOLEN and GA algorithms at different vehicle speeds.

[0036] Figure 6 This is a diagram showing the influence of vehicle speed on the total capacity of cellular links under different V2V link signal-to-interference-noise ratio thresholds according to the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Embodiment 1: Figure 1 As shown, this embodiment provides a technical solution: a resource allocation solution for V2V user groups, including the following steps:

[0039] S1. V2V user grouping. First, construct an interference graph. The vertex set is defined as V. Each vertex in the vertex set V represents a cellular user or a V2V user. Each edge in the edge set E has a weight, which represents the interference between two vertices.

[0040] In step S1, the specific steps are: the weight of the edge set Represents two vertices V i and V j The potential mutual interference between , defined as the sum of the mutual interference between two vertices, can be expressed as: in, Represents the vertex V iVertex V j The interference caused Then it means that the vertex V j Vertex V i The interference caused by different reuse conditions is not a specific value, but an M×M interference matrix. It can be expressed as: In step S1, the specific steps are as follows: The goal of V2V user grouping is to divide the K VUE users in the system into M groups, and the group set is defined as G M ={1,2,…,M}, the VUEs that reuse the same cellular link resources are the same group of users. In order to divide the VUE users with strong interference into different groups, the grouping target is set to: In step S1, the specific steps are: min represents the minimum value of the sum of all co-channel interferences in the same group, Represents the sum of all co-channel interferences in the same group. First, the potential interference between vehicles is quantified by constructing an interference graph. The vertices in the interference graph represent vehicles or cellular users, while the edges represent the possible interference relationships between vertices. The weight of each edge is used to represent the intensity and impact of this interference. In this way, it is possible to intuitively detect which vehicles' communications may cause greater interference, thereby providing a basis for subsequent user grouping. In the process of V2V user grouping, the VUE users in the system are divided into several groups so that the interference between users in the same group is as small as possible, while users in different groups avoid mutual interference as much as possible. By adopting a grouping algorithm based on an interference matrix, the algorithm calculates the mutual interference between vertices and considers the different multiplexing conditions to represent the interference value in a matrix form. Then, according to this interference matrix, users with strong interference are divided into different groups to minimize the sum of co-channel interferences in the same group. Through this grouping method, mutual interference between vehicles can be effectively reduced, the efficiency and accuracy of data transmission can be improved, and more reliable information support can be provided for driving decisions.

[0041] Embodiment 2: S2, resource allocation power control, in order to ensure the communication quality of V2V users, the interruption probability is used to ensure the communication reliability, which can be expressed as follows: In step S2, the specific steps are: represents the minimum SINR required for V2V users to establish a reliable link, p 0 represents the tolerable interruption probability on the physical layer of the V2V link. Combined with the maximum transmission power constraints of V2V users and cellular users, the optimal transmission power of cellular users is solved as: In step S2, the specific steps are: wherein, α is the large-scale fading component of the communication link, including path loss and shadow fading. In step S2, the specific steps are: wherein, is an N GM ×1 matrix, storing the m-th multiplexing group The optimal transmission power of a VUE user pair, Indicates that the same multiplexing group The channel gain from a VUE transmitting user to a CUE user is calculated. First, a standard based on the interruption probability is set. The interruption probability is a key indicator for measuring the stability of the communication link. Its setting value directly reflects the system's requirements for communication. Then, it goes deep into the specific calculation steps. In this link, the minimum signal-to-interference-noise ratio required for V2V users to establish a reliable link is a key parameter to ensure that the quality of data transmission is not interfered with. At the same time, the tolerable interruption probability on the physical layer of the V2V link is considered, so that the system can maintain sufficient stability when facing uncertainties in the actual communication environment. In order to solve the optimal transmission power of cellular users, by combining the maximum transmission power constraints of V2V users and cellular users, this step not only considers the communication efficiency, but also takes into account the safe operation and energy consumption management of the equipment. , under various constraints, the optimal transmission power setting of cellular users, in terms of large-scale fading components of communication links, by analyzing in detail the impact of path loss and shadow fading on signal transmission, the system can more accurately simulate the signal attenuation in the actual communication environment, thereby providing a more reliable basis for subsequent power control and resource allocation. Finally, the optimal transmission power information of VUE user pairs in the reuse group is stored through the matrix, which not only facilitates data storage and management, but also provides strong support for efficient resource scheduling and power control. At the same time, the channel gain of VUE transmitting users to CUE users in the same reuse group. The introduction of this parameter enables the system to more accurately evaluate the interference between different users, and make corresponding power adjustments and optimizations accordingly;

[0042] Embodiment 3: S3, multiplexing matching. In order to maximize the overall total capacity of the system, it is necessary to reasonably match the grouped V2V multiplexing groups with the cellular link resources one by one. In step S3, the specific steps are as follows: Substituting the optimal transmission power of CUE and VUE obtained in step 2 into the Shannon formula to obtain the maximum communication capacity of the cellular user, and converting the maximum capacity Each row of the coefficient matrix composed of is subtracted from its minimum value, and each column of the coefficient matrix after completing the first step is subtracted from its minimum value. In step S3, the specific steps are: use the smallest row and column to cover the elements in the coefficient matrix that are already zero. If the sum of the row and the column is n, the algorithm ends, otherwise proceed to the next step. In step S3, the specific steps are: find the minimum value of the uncovered elements, subtract the minimum value from all uncovered elements, add the minimum value to the elements whose rows and columns are covered once, and then return to the previous step. In the execution of step S3, we first integrate the optimal transmission power data of CUE and VUE obtained in the previous step into the Shannon formula, so as to accurately calculate the maximum communication capacity of cellular users. Next, the system constructs a maximum capacity value composed of these maximum capacity values. The coefficient matrix composed of the coefficient matrix is ​​first normalized, that is, the minimum value of the row is subtracted to make the starting point of each row the same, and then the same process is performed on each column, subtracting the minimum value in the column. This step ensures that each element in the coefficient matrix can be compared and evaluated on a relatively fair basis. Then the system uses an algorithm to cover and optimize the elements in the coefficient matrix. Specifically, the algorithm will first try to cover the elements in the matrix that are already zero with the smallest rows and columns. If the sum of the rows and columns meets the predetermined conditions, such as being equal to the total dimension of the matrix or a preset threshold, the algorithm will end, indicating that the current resource allocation plan has reached the optimal or near-optimal state. However, if this condition is not met, the algorithm will enter step 2 until the condition is met;

[0043] in, Figure 2 The figure shows the influence of different ratios of the number of V2V users to the number of cellular users on the total capacity of CUE users in the system. The horizontal axis in the figure represents the ratio of the number of VUE users to the number of CUE users. The larger the ratio, the more VUEs there are in the system, and the more VUEs reuse cellular link resources in the same reuse group, and the more serious the interference to cellular users. The vertical axis represents the total capacity of cellular users in the system. It can be clearly seen from the figure that under the three different algorithms, as the value of K / M increases, the total capacity of cellular users is constantly decreasing. This is because as the number of VUE users in the system increases, the number of VUE users who reuse the same cellular link resources in the same group will also increase. More VUE users share the same cellular user spectrum resources, which will inevitably cause more interference at the cellular users during communication, thereby causing the total capacity of CUE users in the system to decrease. In addition, it can be seen from the figure that even if the total capacity of CUE users is decreasing, the V2V user grouping resource allocation algorithm proposed in this paper can still maintain a higher total capacity increase for cellular users compared with the other two algorithms.

[0044] Among them, Figure 3The figure shows the change of the total capacity of cellular users in the system under different cellular user transmission power thresholds. The horizontal axis in the figure is the transmission power threshold of CUE, and the vertical axis is the total capacity of CUE users. It can be seen from the figure that with the increase of the CUE transmission power threshold, the total capacity of CUE is also increasing. At the same time, with the increase of the number of multiplexed vehicles, the total capacity of CUE is decreasing. This is because the increase of the CUE transmission power threshold will increase the optimal transmission power of CUE users, thereby increasing the total capacity of CUE users. The optimal transmission power of VUE users as interference sources will decrease with the increase of CUE transmission power threshold, which will reduce the interference of VUE users to CUE users, thereby further increasing the total capacity of CUE users.

[0045] in, Figure 4 Different VUE signal-to-interference-noise ratio thresholds are given The influence of the ratio of the number of VUE users to the number of CUE users on the total capacity of CUE users in the system is shown in the figure. The horizontal axis in the figure represents the ratio of the number of VUE users to the number of CUE users, and the vertical axis represents the total capacity of cellular users in the system. It can be seen from the figure that as the value of K / M increases, the total capacity of cellular users also decreases. This is related to Figure 2 The results are consistent. The difference is that when the number of multiplexed vehicles is the same, as the VUE signal-to-interference-noise ratio threshold increases, the total capacity of CUE gradually decreases. This performance degradation is due to the increase in the threshold, which reduces the tolerance of VUE users to interference. In other words, VUE users have stricter requirements for multiplexing groups. The direct impact of stricter grouping requirements is that VUE users that were originally able to be multiplexed no longer meet the multiplexing requirements, which in turn causes VUE users in the same group to cause more interference to CUE users, thereby reducing the total capacity.

[0046] in, Figure 5 The figure shows the impact of vehicle speed changes on the total capacity of cellular users. The horizontal axis in the figure represents the driving speed of vehicle users, and the vertical axis represents the total capacity of cellular users. From the overall perspective of the figure, the total capacity of cellular users decreases as the vehicle speed increases under the three different resource allocation algorithms. This is consistent with the theoretical analysis. As the vehicle speed increases, the safety distance between vehicles will increase, which will cause the channel between vehicle users and multiplexed cellular users to change faster. At the same time, the increase in the transmission power of cellular users from 17dBm to 25dBm also increases the total capacity of cellular users.

[0047] In addition, higher vehicle speeds will also increase the channel path loss between the VUE transmitting user and the VUE receiving user. In order to ensure the communication reliability of the V2V link, the V2V user's transmitter will increase the transmission power to compensate for the channel path loss. Therefore, the CUE user whose spectrum resources are reused will be subject to more interference from the VUE user, which will further reduce the total capacity of the CUE users.

[0048] in, Figure 6 The figure shows the impact of vehicle speed on the total capacity of CUE users under different VUE signal-to-interference-noise ratio thresholds. The horizontal axis in the figure is the vehicle speed, and the vertical axis is the total capacity of CUE users. As the vehicle speed increases, the total capacity of CUE users decreases. This trend is consistent with Figure 5 The results presented in are consistent. It is worth noting that as the signal-to-interference-noise ratio threshold of VUE users increases, that is, VUE users have higher requirements for communication reliability, the total capacity of CUE users is also decreasing. This is because at higher vehicle speeds, in order to ensure the communication reliability of the V2V link, the transmitter of the V2V user will increase the transmission power to compensate for the path loss of the channel. When VUE users have higher requirements for communication reliability, the transmitter of the V2V user will further increase the output power, which ultimately causes a decrease in the total capacity of CUE. This also indirectly confirms that Figure 5 conclusion.

[0049] The above description is only a preferred embodiment of the present invention and does not limit the present invention in other forms. Any technician familiar with the profession may use the technical content disclosed above to change or modify it into an equivalent embodiment with equivalent changes and apply it to other fields. However, any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A resource allocation scheme for V2V user grouping, characterized in that: The following steps are involved: S1. V2V user grouping: First, construct an interference graph. The vertex set is defined as V. Each vertex in the vertex set V represents a cellular user or a V2V user. Each edge in the edge set E has a weight, which represents the interference between two vertices. S2. Resource allocation power control: In order to ensure the communication quality of V2V users, the interruption probability is used to ensure communication reliability, which can be expressed as follows: S3. Multiplexing matching: In order to maximize the overall total capacity of the system, it is necessary to reasonably match the grouped V2V multiplexing groups with the cellular link resources one-to-one.

2. A resource allocation scheme for V2V user grouping according to claim 1, characterized in that: In step S1, the specific steps are: the weight of the edge set Represents two vertices V i and V j The potential mutual interference between , defined as the sum of the mutual interference between two vertices, can be expressed as: in Represents the vertex V i Vertex V j The interference caused Then it means that the vertex V j Vertex V i The interference caused by different reuse conditions It is not a specific value, but an M×M interference matrix. Interference matrix It can be expressed as:

3. A resource allocation scheme for V2V user grouping according to claim 1, characterized in that: In step S1, the specific steps are as follows: the goal of V2V user grouping is to divide the K VUE users in the system into M groups, and the group set is defined as: G M ={1,2,…,M}; The VUEs that reuse the same cellular link resources are grouped as users. In order to divide the VUE users with strong interference into different groups, the grouping target is set as:

4. The resource allocation scheme for V2V user grouping according to claim 1, characterized in that: In step S1, the specific steps are: min represents the minimum value of the sum of all co-channel interferences in the same group, Represents the sum of all co-channel interference in the same group.

5. A resource allocation scheme for V2V user grouping according to claim 1, characterized in that: In step S2, the specific steps are: represents the minimum SINR required for V2V users to establish a reliable link, and p0 represents the tolerable interruption probability on the physical layer of the V2V link. Combining the maximum transmission power constraints of V2V users and cellular users, the optimal transmission power of cellular users is solved as:

6. A resource allocation scheme for V2V user grouping according to claim 1, characterized in that: In step S2, the specific steps are: wherein, α is the large-scale fading component of the communication link, including path loss and shadow fading.

7. The resource allocation scheme for V2V user grouping according to claim 1, characterized in that: In step S2, the specific steps are: wherein, is a The matrix stores the m-th multiplexing group The optimal transmission power of a VUE user pair, Indicates that the same multiplexing group The channel gain from a VUE transmitting user to a CUE user.

8. The resource allocation scheme for V2V user grouping according to claim 1, characterized in that: In step S3, the specific steps are: Substituting the optimal transmission power of CUE and VUE obtained in step 2 into the Shannon formula to obtain the maximum communication capacity of the cellular user, and converting the maximum capacity Each row of the coefficient matrix is ​​subtracted from its minimum value, and each column of the coefficient matrix after completing the first step is subtracted from its minimum value.

9. The resource allocation scheme for V2V user grouping according to claim 1, characterized in that: In step S3, the specific steps are: use the smallest row and column to cover the elements in the coefficient matrix that are already zero. If the sum of the row and the column is n, the algorithm ends, otherwise proceed to the next step.

10. A resource allocation scheme for V2V user grouping according to claim 9, characterized in that: In step S3, the specific steps are: find the minimum value among the uncovered elements, subtract the minimum value from all the uncovered elements, add the minimum value to the elements whose rows and columns are covered once, and then return to the previous step.

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