C-V2X resource allocation method based on V2I communication demand analysis

Abstract

The invention discloses a C-V2X resource allocation method based on V2I communication demand analysis, and the method comprises the steps: building a channel model in an application scene, and calculating the signal to interference plus noise ratio of a V2I link and a V2V link; establishing a V2I link data stream transmission model, modeling a V2I link data packet queue into a discrete time Markov chain, and performing queue analysis on the V2I link data packet queue by using a queuing theory tool; according to the steady-state probability of the V2I link data packet queue in the steady state, converting the capacity demand of the V2I link into the average queuing delay demand of the V2I link data packet queue; constructing a resource allocation model which takes minimization of the average packet loss rate of a V2I link in the C-V2X system as an optimization target; and solving the resource allocation model by using a heuristic algorithm to obtain a resource allocation scheme. According to the invention, the real-time load condition of the V2I link is considered, system resource allocation can be carried out according to the real-time load condition of the V2I link, the performance of the V2I link in an actual communication environment is improved, and the reliability of the V2I link can be ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of C-V2X communication, and particularly relates to a C-V2X resource allocation method based on V2I communication requirement analysis. Background Art

[0002] The C-V2X technology jointly completes the construction of a communication network through V2V links, V2I links, V2P links and V2N links. The purpose of the C-V2X technology is to enable traffic participants to communicate with each other through modern communication technologies to improve road safety, enhance traffic efficiency, and provide communication support for autonomous driving and advanced driver assistance systems.

[0003] Vehicle-road cooperation technology is one of the core technologies in autonomous driving and advanced driver assistance systems. In vehicle-road cooperation technology, changes in vehicle density, road traffic conditions, and user needs lead to changes in the communication requirements of the C-V2X system. This requires high-frequency information interaction between vehicles and roadside devices to ensure the timeliness and reliability of information. The high-frequency information interaction between vehicles and roadside devices requires the V2I link to have the characteristics of low latency and high reliability to meet the real-time requirements of vehicle-road cooperation technology. Therefore, how to effectively improve the reliability of the V2I link while ensuring the latency of the V2I link is an important issue in C-V2X communication.

[0004] Queueing theory, as a theory for studying system resource allocation and scheduling, is a powerful tool for analyzing and optimizing communication networks. As described in the article "Resource Allocation for Vehicular Communications With Low Latency and High Reliability" published by Guo Chongtao et al. in IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS, queueing theory tools are used to analyze the latency and reliability requirements of communication links in C-V2X. In this technical literature, the Poisson distribution is used to model the arrival process of communication link data packets, but this cannot describe the characteristics that different service data packets in the C-V2X system communication link have different arrival frequencies. At the same time, this technical literature analyzes the communication requirements of the V2I link from the perspective of link capacity, which cannot accurately describe the specific latency and reliability of the V2I link. Summary of the Invention

[0005] The purpose of the present invention is to solve the above-mentioned defects in the prior art, and provide a C-V2X resource allocation method based on V2I communication requirement analysis, aiming to ensure the low latency and high reliability of the V2I link and improve the communication quality of the V2I link.

[0006] To achieve the object of the present invention, the present invention provides a C-V2X resource allocation method based on V2I communication requirement analysis. This method is applied to a high-density vehicle scenario, where there are M vehicles moving on the road at a speed of V. K V2V links are established between the vehicles, and M V2I links are established between the vehicles and the base station. The method includes the following steps:

[0007] S1. Establish a channel model in the scenario and calculate the signal-to-interference-plus-noise ratio (SINR) of the V2I links and V2V links.

[0008] S2. Establish a data stream transmission model for the V2I links, model the V2I link packet queue as a discrete-time Markov chain, and use queuing theory tools to analyze the V2I link packet queue.

[0009] S3. According to the parameters of the V2I link packet queue in the steady state, convert the capacity requirement of the V2I link into the average queuing delay requirement of the V2I link packet queue.

[0010] S4. With the probability that the average queuing delay of the V2I link packet queue is lower than the maximum tolerable average queuing delay of the V2I link and the SINR of the V2V link is lower than the minimum tolerable SINR of the V2V link being less than the outage probability threshold as the constraint condition, construct a resource allocation model with the objective of minimizing the average packet loss rate of the V2I links in the C-V2X system.

[0011] S5. Use a heuristic algorithm to determine the power of the V2V links and V2I links and the resource allocation scheme between the V2V links and V2I links.

[0012] The present invention has the following advantages and effects compared with the prior art:

[0013] (1) A C-V2X resource allocation method based on V2I communication requirement analysis disclosed by the present invention takes into account the real-time load situation of the V2I links, can allocate system resources according to the real-time load situation of the V2I links, and improves the performance of the V2I links in the actual communication environment.

[0014] (2) A C-V2X resource allocation method based on V2I communication requirement analysis disclosed by the present invention introduces queuing theory tools to analyze the real-time communication requirements of the V2I links, converts the capacity requirement of the V2I links into the requirement for the average queuing delay of the V2I link packet queue, and ensures the low-latency characteristics of the V2I links.

[0015] (3) Taking the minimization of the average packet loss rate of the V2I link packet queue in the scenario as the optimization objective of the resource allocation model improves the reliability of the V2I links and ensures the communication effect between vehicles and roadside devices in the vehicle-road cooperation technology. Description of the Drawings

[0016] Figure 1 It is a schematic diagram of the physical model based on the C-V2X resource allocation method disclosed in the embodiments of the present invention.

[0017] Figure 2 It is a flowchart of the C-V2X resource allocation method based on the analysis of V2I communication requirements disclosed in the embodiments of the present invention.

[0018] Figure 3 It is the graph of the simulation result of the average packet loss rate of the V2I link packet queue of the C-V2X resource allocation method disclosed in the embodiments of the present invention with the arrival rate λ of the V2I link packet m,1 changing.

[0019] Figure 4 It is the graph of the simulation result of the average packet loss rate of the V2I link packet queue of the C-V2X resource allocation method and the simulated annealing allocation method disclosed in the embodiments of the present invention with the arrival rate λ of the V2I link data m,1 changing. Detailed implementation manners

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0021] As Figure 1 shown, a C-V2X resource allocation method based on the analysis of V2I communication requirements provided by the embodiments of the present invention has an application scenario of an urban scenario in the urban Manhattan model. The base station coverage radius is R. There are M vehicles traveling on the road at a speed of V in the C-V2X system. K V2V links are constructed between the vehicles, and M V2I links are constructed between the vehicles and the base station. Figure 2 The flowchart of the entire inventive method is shown. A C-V2X resource allocation method based on the analysis of V2I communication requirements specifically includes the following steps:

[0022] S1. Establish a channel model in a high-density vehicle scenario, establish an interference management model for V2V links and V2I links in the scenario, and calculate the signal-to-interference-plus-noise ratio of the V2I link and the signal-to-interference-plus-noise ratio of the V2V link where m represents the mth V2I link and k represents the kth V2V link.

[0023] In one embodiment of the present invention, the high-density vehicle scenario is an urban scenario.

[0024] The process of this step is as follows:

[0025] (1) Establish a channel model in the urban scenario, and the channel model is:

[0026] g u,v,f = α u,v,f β u,v,f ;

[0027] In the formula, g u,v,f represents the channel gain between the transmitter of the u-th link and the receiver of the v-th link transmitted using the f-th resource block (RB), and β u,v,f = |h u,v,f | 2 represents small-scale fading information, h u,v,f obeys CN(0,1), is independent of different resource blocks RB and links, and CN represents complex Gaussian distribution; α u,v,f represents large-scale fading information, including path loss and shadow, and is assumed to be independent of different resource blocks RB.

[0028] (2) Define spectrum allocation indicators, including and

[0029] indicates whether the m-th V2I link uses the f-th resource block RB for transmission, indicates whether the k-th V2V link uses the f-th resource block RB for transmission; the spectrum allocation indicator is binary. When , it means that the m-th V2I link uses the f-th resource block RB for transmission. Conversely, if then it does not use the f-th resource block RB for transmission; when , it means that the k-th V2V link uses the f-th resource block RB for transmission. Conversely, if then it does not use the f-th resource block RB for transmission;

[0030] (3) The formula for calculating the signal-to-interference-plus-noise ratio of the k-th V2V link is as follows:

[0031]

[0032] Among them, respectively represent the transmission powers of the transmitter of the m-th V2I link and the transmitter of the k-th V2V using the f-th resource block RB, g k,k,f , g m,k,f , gk′,k,f respectively represent the channel gains of the k-th V2V link, the m-th V2I link, and the k'-th V2V link that use the f-th resource block RB to interfere with the V2V link transmitted using the f-th resource block RB, σ 2 represents the power spectral density of additive white Gaussian noise;

[0033] (4) The signal-to-interference-plus-noise ratio of the m-th V2I link The calculation formula is as follows:

[0034]

[0035] where, g m,B,f , g k,B,f respectively represent the channel power gains of the m-th V2I link and the k-th V2V link that are transmitted through the f-th resource block RB and interfere with the V2I link transmitted using the f-th resource block RB, and B represents the base station.

[0036] S2. Establish a data stream transmission model for the V2I link and model the V2I link data packet queue as a discrete-time Markov chain, and use queuing theory tools to perform queue analysis on the V2I link data packet queue.

[0037] The process of this step is as follows:

[0038] (1) In one embodiment of the present invention, the C-V2X system uses a 10 ms radio frame. Each radio frame contains 10 sub-frames of 1 ms. The length of each sub-frame is equivalent to the length of two time slots. 0.5 ms is used as a time slot T to study the data packet queuing situation of the V2I link;

[0039] (2) The base station performs resource allocation every N time slots to ensure the effectiveness of resource allocation. In a queue analysis, the transmission power and resource allocation of each link in the C-V2X system do not change with the change of time slots;

[0040] (3) For the channel gains of each link, since it is determined by the vehicle position and the vehicle speed is slow in a high-density vehicle environment, the large-scale fading information of the channel is reliable within a certain period of time. In a queue analysis, the large-scale fading information of the channel does not change with the change of time slots, but the small-scale fading information of the channel changes with the change of time slots;

[0041] (4) For the t-th moment, the length of the data packet queue of the m-th V2I link is modeled as a discrete-time Markov chain The state space S of the discrete-time Markov chain I is as follows:

[0042] SI = {0, 1, 2, ..., B I - 1, B I};

[0043] where B I is the size of the V2I link data packet buffer;

[0044] (5) Assume that the data packet arrival process of the m-th V2I link at time t follows a Markov modulated Poisson process. In the Markov modulated Poisson process, the state set S MMPP = {s m,1 , s m,2}, the arrival rate set λ MMPP = {λ m,1 , λ m,2}. Then the state transition matrix Λ MMPP of the Markov modulated Poisson process is:

[0045]

[0046] where q m,x,y represents the state transition probability that the Markov chain of the Markov modulated Poisson process in the data packet arrival process of the m-th V2I link transfers from state x to state y. The state of this Markov chain represents different arrival rates of the data packet arrival process of the V2I link. x = 1, 2, y = 1, 2, s m,1 , s m,2 represent two states of the Markov chain of the Markov modulated Poisson process in the data packet arrival process of the m-th V2I link, and λ m,1 , λ m,2 represent the data packet arrival rates corresponding to states s m,1 , s m,2 .

[0047] (6) The steady-state probability of the Markov chain in the Markov modulated Poisson process in the data packet queue of the m-th V2I link is:

[0048] π m = (π m,1 , π m,2 );

[0049] where

[0050] π m,1 , π m,2 are the probabilities of being in states 1 and 2 respectively in the steady state of the Markov chain of the Markov modulated Poisson process in the data packet arrival process of the m-th V2I link.

[0051] (7) The data packet arrival process of the m-th V2I link Probability mass function is as follows:

[0052]

[0053] π m,z represents the probability of being in state z in the steady state of the Markov chain in the Markov-modulated Poisson process of the packet arrival process of the m-th V2I link, and n represents the number of packets arriving at the m-th V2I link.

[0054] (8) Capacity of the m-th V2I link at time t is expressed as:

[0055]

[0056] where W represents the total bandwidth of the C-V2X system, F represents the number of resource blocks RB used in the C-V2X system, α m,B represents the large-scale fading information of the channel from the transmitter of the m-th V2I link to the base station, and β m,B,f (t) represents the small-scale fading information of the channel from the transmitter of the m-th V2I link to the base station at time t, and α k,B represents the large-scale fading information of the interference channel from the transmitter of the k-th V2V link to the base station of the V2I link receiver, and β k,B,f (t) represents the small-scale fading information of the interference channel from the transmitter of the k-th V2V link to the base station of the V2I link receiver at time t.

[0057] The transmitter of the V2I link is a vehicle, the receiver of the V2I link is a base station, and the transmitters and receivers of the V2V link are both vehicles.

[0058] (9) Number of packets served by the m-th V2I link within a time slot T Probability mass function

[0059] is as follows:

[0060]

[0061] where L I represents the size of the V2I link packet, represents the capacity of the m-th V2I link at time t, d is the differential symbol, and β m,B,f represents the small-scale fading information of the channel from the transmitter of the m-th V2I link to the base station, and β k,B,f represents the small-scale fading information of the interference channel from the transmitter of the k-th V2V link to the base station of the V2I link receiver.

[0062] (10) For the convenience of analysis, the data packets transmitted in each time slot first leave the queue, and then the data packets arriving in the previous time slot enter the queue. Thus, the length of the data packet queue of the m-th V2I link at time t + 1 can be expressed as:

[0063]

[0064] where, represents the probability mass function of the number of data packets leaving the queue of the V2I link at time t + 1;

[0065] (11) From the formulas in (7) and (9), are both independent of time t. Combining with the queue state transition probability is also independent of time t, can be degenerated into which can be defined as:

[0066] When i = 0, 0 ≤ j < B I ,

[0067] represents the probability that the number of data packets arriving at the m-th V2I link is j;

[0068] When i = 0, j = B I ,

[0069] l is the symbol for accumulation, represents the probability that the number of data packets arriving at the m-th V2I link is l;

[0070] When 1 ≤ i ≤ B I , j = 0,

[0071] represents the probability that the number of data packets arriving at the m-th V2I link is 0, represents the probability that the number of data packets leaving the m-th V2I link is l;

[0072] When 1 ≤ i ≤ B I , 1 ≤ j ≤ i, j ≠ B I ,

[0073]

[0074] represents the probability that the number of data packets leaving the m-th V2I link is i - j + l. n is the symbol for accumulation, represents the probability that the number of data packets leaving the m-th V2I link is n;

[0075] When \(1\leq i\leq B\) I , \(i < j < B\) I ,

[0076]

[0077] denotes the probability that the number of packets arriving at the \(m\)-th V2I link is \(j - i+1\);

[0078] When \(1\leq i\leq B\) I , \(j = B\) I ,

[0079]

[0080] denotes the probability that the number of packets arriving at the \(m\)-th V2I link is \(n\);

[0081] (12) According to the expression in (11) to obtain the one-step state transition probability matrix which can be expressed as:

[0082]

[0083] wherein, denotes the state transition probability, denotes the length of the packet queue of the \(m\)-th V2I link at time \(t\) the probability of transitioning from state \(i\) to state \(j\), where \(i\) and \(j\) represent the states of the Markov chain formed by the lengths of the V2I link packet queues, and the states of this Markov chain represent different queue lengths of the V2I link packet queues, and the value ranges of \(i\) and \(j\) are \((0, 1, \ldots, B\) I ).

[0084] S3. According to the steady-state probability of the V2I link packet queue under steady state, convert the capacity requirement of the V2I link into the average queuing delay requirement of the V2I link packet queue.

[0085] The process of this step is as follows:

[0086] (1) For a time-homogeneous, irreducible, and aperiodic discrete-time Markov chain, there exists a unique steady-state probability vector \(\pi\) that satisfies The steady-state vector \(\pi\) of the \(m\)-th V2I link queue m,I can be expressed as:

[0087]

[0088] wherein, Indicates that the number of data packets in the V2I link data packet queue buffer is B I at the steady-state probability

[0089] (2) The steady-state average queue length of the m-th V2I link queue can be expressed as as follows

[0090]

[0091] where is a random variable representing the steady-state queue length of the m-th V2I link as t approaches infinity, indicating the steady-state probability when the number of data packets in the V2I link data packet queue buffer is c

[0092] (3) Considering a queuing state n I (n I = 1, 2, …, B I ), the number of lost packets of the m-th V2I link queue can be expressed as

[0093]

[0094] (4) According to (3), the average packet loss rate of the m-th V2I link queue under steady state can be expressed as

[0095]

[0096] where represents the average packet arrival rate of the data packets of the m-th V2I link, representing the average number of data packets arriving at the V2I link queue within one time slot;

[0097] (5) According to (2), (3), and (4), the average queuing delay of the k-th link queue under steady state can be expressed as

[0098]

[0099] (6) The average queuing delay requirement of the m-th V2I link queue is

[0100]

[0101] where is the maximum tolerable average queuing delay of the V2I link

[0102] S4. Taking the average queuing delay of the V2I link data packet queue Lower than the maximum average queuing delay tolerable by the V2I link and the signal-to-interference-plus-noise ratio of the V2V link Lower than the minimum signal-to-interference-plus-noise ratio tolerable by the V2V link With the probability being less than the outage probability threshold p0 as the constraint, a resource allocation model is constructed with the objective of minimizing the average packet loss rate of the V2I link in the C-V2X system. The established resource allocation model is as follows:

[0103] P1:

[0104] C1:

[0105] C2:

[0106] C3:

[0107] C4:

[0108] C5:

[0109] C6:

[0110] C7:

[0111] C8:

[0112] Among them, P1 is the optimization objective, and C1, C2, C3, C4, C5, C6, C7, and C8 are all constraints. Represents the minimum signal-to-interference-plus-noise ratio tolerable by the V2V link. and Represent the maximum transmit powers of the V2I link transmitter and the V2V link transmitter respectively. Represents the signal-to-interference-plus-noise ratio of the V2V link Lower than the minimum signal-to-interference-plus-noise ratio tolerable by the V2V link Probability.

[0113] S5. Use a heuristic algorithm to determine the powers of the V2V link and the V2I link and the resource allocation scheme between the V2V link and the V2I link.

[0114] The process of this step is as follows:

[0115] (1) Divide the resource block RB resources into M equal parts and randomly allocate them to each V2I link;

[0116] (2) Model the resource block RB selection status of each V2V link. The cluster selection state space S = {1, 2,..., M};

[0117] (3) Use the series theorem to convert the probability limit of the signal-to-interference-plus-noise ratio (SINR) of the V2V link into a limit on the SINR of the V2V link. The SINR limit of the V2V link is:

[0118]

[0119] (4) Obtain the matrix channel gain matrix Φ of the V2V link transmitted using the f-th resource block RB according to the channel power gain of the link:

[0120]

[0121] where, has no practical meaning;

[0122] (5) Obtain it using the power control expression. The expression is:

[0123]

[0124] where, N f represents the number of V2V links transmitted using the f-th resource block RB. I is a matrix with all elements being 1. φ i represents the i-th row of the Φ -1 matrix, and the superscript T represents the transpose; represents the large-scale channel fading information of the interference channel of the V2I link that the V2V link transmitted using the f-th resource block RB is subject to. N f represents the number of V2V links transmitted using the f-th resource block RB.

[0125] (6) Calculate the average packet loss rate of the V2I link in the C-V2X system after the k-th V2V link reselects the f-th resource block RB for transmission according to the power control expression in step (5)

[0126] (7) The probability that the k-th V2V link selects the f-th resource block RB for transmission is:

[0127]

[0128] (8) For each iteration, complete a resource block RB selection for all V2V links. Repeat steps (6) and (7) until the algorithm converges to obtain the resource allocation scheme for the V2I link and the V2V link;

[0129] (9) Obtain the transmit powers of the V2I link and the V2V link using the power control expression in step (5).

[0130] In one embodiment of the present invention, in the performance simulation experiment, the number of reliable V2V links in the C-V2X system is mainly selected as the measurement index. The main simulation experiment parameters are shown in Table 1 below.

[0131] Table 1. Main Simulation Experiment Parameter Table

[0132]

[0133]

[0134] As Figure 3 shown, it is the theoretical and simulation results of the relationship between the average packet loss rate of the V2I link data packet queue and the arrival rate λ m,1 of the Markov modulated Poisson process of the V2I link data packet in the C-V2X system. It can be seen from the comparison of the theoretical and simulation results that the analysis of the V2I link data packet queue is effective. For different data packet buffer situations, when the arrival rate λ m,1 of the Markov modulated Poisson process of the V2I link data packet is large enough, the data packet buffer tends to be full in the steady state. A larger data packet buffer can allow more V2I link data packets to queue up without choosing to discard packets, which results in a lower average packet loss rate in the case of a larger data packet buffer. This proves the effectiveness of the queuing model of the V2I link data packet queue.

[0135] As Figure 4 shown, it is the comparison chart of the simulation results of the average packet loss rate of the V2I link data packet queue and the arrival rate λ m,1 of the Markov modulated Poisson process of the V2I link data packet in the C-V2X system and the results of the resource allocation method proposed in this embodiment and the simulated annealing allocation method in the same simulation environment. Considering that there are few resource allocation methods for the V2I link communication demand analysis in this embodiment, only the method proposed in this embodiment is compared and analyzed with the simulated annealing allocation method. Compared with the simulated annealing allocation method, the method proposed in this embodiment significantly reduces the packet loss rate of the V2I link and effectively improves the reliability of the V2I link.

[0136] The method provided in the foregoing embodiment of the present invention uses the Poisson distribution based on Markov modulation to model the arrival process of communication link data packets to describe the characteristics of different service data packet arrival rates in the communication link of the C-V2X system; uses queuing theory tools to analyze the communication demand of the V2I link, analyzes the real-time load situation of the V2I link, converts the capacity demand of the V2I link into the average queuing delay demand of the V2I link, can more accurately represent the real-time communication demand of the V2I link, sets the optimization goal as minimizing the average packet loss rate of the V2I link, and improves the reliability of the V2I link.

[0137] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A C-V2X resource allocation method based on the analysis of V2I communication requirements, characterized in that, There are M vehicles moving on the road at a speed of V in the scenario. K V2V links are established between the vehicles, and M V2I links are established between the vehicles and the base station. The method includes the following steps: Establish a channel model in the scenario, and calculate the signal-to-interference-plus-noise ratio (SINR) of the V2I links and V2V links; Establish a data flow transmission model for the V2I links, model the V2I link packet queue as a discrete-time Markov chain, and use queuing theory tools to perform queue analysis on the V2I link packet queue; According to the steady-state probability of the V2I link packet queue in the steady state, convert the capacity requirement of the V2I link into the average queuing delay requirement of the V2I link packet queue; Taking the probability that the average queuing delay of the V2I link packet queue is lower than the maximum tolerable average queuing delay of the V2I link and the SINR of the V2V link is lower than the minimum tolerable SINR of the V2V link being less than the outage probability threshold as a constraint condition, construct a resource allocation model with the optimization goal of minimizing the average packet loss rate of the V2I links in the C-V2X system; Use a heuristic algorithm to determine the power of the V2V links and V2I links and the resource allocation scheme between the V2V links and V2I links.

2. The C-V2X resource allocation method based on V2I communication requirement analysis according to claim 1, wherein The channel model is: g u,v,f ＝α u,v β u,v,f ； where g u,v,f represents the channel gain between the transmitter of the u-th link and the receiver of the v-th link transmitted using the f-th resource block RB; β u,v,f represents small-scale fading information; α u,v represents large-scale fading information.

3. A C-V2X resource allocation method based on V2I communication requirement analysis according to claim 1, characterized in that, The calculation formula for the SINR of the V2I links and V2V links is: Signal-to-Interference-plus-Noise Ratio (SINR) of the k-th V2V link The calculation formula is as follows: Among them, respectively represent the transmission power of the m-th V2I link transmitter and the k-th V2V transmitter using the f-th resource block RB, g k,k,f , g m,k,f , g k′,k,f respectively represent the channel gains of the k-th V2V link, the m-th V2I link, and the k'-th V2V link using the f-th resource block RB interfering with the V2V link using the f-th resource block RB, σ 2 represents the power spectral density of additive white Gaussian noise; Signal-to-Interference-plus-Noise Ratio (SINR) of the m-th V2I link The calculation formula is as follows: where, g m,B,f , g k,B,f respectively represent the channel power gain of the interference of the k-th V2V link pair on the m-th V2I link transmitted through the f-th RB, and B represents the base station.

4. A C-V2X resource allocation method based on V2I communication requirement analysis according to claim 1, characterized in that, The establishment of the data flow transmission model for the V2I links, modeling the V2I link packet queue as a discrete-time Markov chain, and using queuing theory tools to perform queue analysis on the V2I link packet queue includes: The base station performs resource allocation every N time slots. In one queue analysis, the transmission power and resource allocation of each link in the C-V2X system do not change with the change of time slots; For the channel gain of each link, in one queue analysis, the large-scale fading information of the channel does not change with the change of time slots, but the small-scale fading information of the channel changes with the change of time slots; For time t, model the packet queue length of the m-th V2I link as a discrete-time Markov chain; Assume the packet arrival process of the m-th V2I link at time t obeys a Markov modulated Poisson process. Determine the state set, arrival rate set, and state transition matrix Λ of the Markov modulated Poisson process MMPP ; Determine the steady-state probability of the Markov chain in the Markov modulated Poisson process; Construct the packet arrival process of the m-th V2I link The probability mass function of; Determine the capacity of the m-th V2I link at time t The number of data packets served by the m-th V2I link within a time slot T Probability mass function; Determine the packet queue length of the m-th V2I link at time t + 1 Define the queue of the m-th V2I link State transition probability Based on the state transition probability Obtain the one-step state transition probability matrix 5. A C-V2X resource allocation method based on V2I communication requirement analysis according to claim 4, characterized in that, The number of data packets served by the m-th V2I link within a time slot T has a probability mass function given by: Among them, L I represents the size of the V2I link data packet, and β m,B,f represents the small-scale fading information of the channel from the transmitter of the m-th V2I link to the base station, and β k,B,f represents the small-scale fading information of the interference channel of the transmitter of the k-th V2V link to the base station of the V2I link receiver, respectively represent the transmission powers of the transmitter of the m-th V2I link and the transmitter of the k-th V2V link using the f-th resource block RB, and α k,B represents the large-scale fading information of the interference channel of the transmitter of the k-th V2V link to the base station of the V2I link receiver, and ɑ m,B represents the large-scale fading information of the channel from the transmitter of the m-th V2I link to the base station, represents whether the m-th V2I link uses the f-th resource block RB for transmission, represents whether the k-th V2V link uses the f-th resource block RB for transmission.

6. A C-V2X resource allocation method based on V2I communication demand analysis according to claim 4, characterized in that, The m-th V2I link queue State transition probability It is defined as: When i = 0, 0 ≤ j < B I At this time Denote the probability that the number of arriving data packets on the m-th V2I link is j; When i = 0 and j = B I at that time When 1 ≤ i ≤ B I , and j = 0 When 1 ≤ i ≤ B I , 1 ≤ j ≤ i, j ≠ B I when When 1 ≤ i ≤ B I , i < j < B I when When 1 ≤ i ≤ B I , j = B I when 7. A C-V2X resource allocation method based on V2I communication requirement analysis according to claim 4, wherein, In the conversion of the capacity requirement of the V2I link into the average queuing delay requirement of the V2I link packet queue according to the steady-state probability of the V2I link packet queue in the steady state, the average queuing delay requirement of the m-th V2I link queue is: Among them, is the highest tolerable average queuing delay of the V2I link, represents the average queuing delay of the data queue of the k-th link under steady state; The average queuing delay of the data queue of the k-th link in the steady state It is expressed as: Denote the steady - state average queue length of the \(m\) - th V2I link queue , Denote the average packet loss rate of the \(m\) - th V2I link queue in the steady state, is a random variable representing the steady - state queue length of the \(m\) - th V2I link when \(t\) approaches infinity, is a random variable representing the steady - state queue length of the \(m\) - th V2I link when \(t\) approaches infinity, Denote the steady - state probability when the number of packets in the V2I link packet queue buffer is \(c\). \(j\) represents the state of the Markov chain formed by the V2I link packet queue length, Denote the average packet arrival rate of the packets of the \(m\) - th V2I link.

8. A C-V2X resource allocation method based on V2I communication requirement analysis according to claim 1, characterized in that The resource allocation model is expressed as: P1： C1： C2： C3： C4： C5： C6： C7： C8： Among them, P1 is the optimization objective, and C1, C2, C3, C4, C5, C6, C7, and C8 are all constraint conditions. represents the minimum signal-to-interference-plus-noise ratio (SINR) that the V2V link can tolerate. and represent the maximum transmit powers of the V2I link transmitter and the V2V link transmitter, respectively. represents the SINR of the V2V link below the minimum tolerable SINR of the V2V link probability.

9. A C-V2X resource allocation method based on V2I communication demand analysis according to any one of claims 1-8, characterized in that, Use a heuristic algorithm to determine the power of the V2V links and V2I links and the resource allocation scheme between the V2V links and V2I links. The process is as follows: S51. Divide the resource block (RB) resources into M equal parts and randomly allocate them to each V2I link; S52. Model the RB selection status of each V2V link; S53. Convert the probability limit of the SINR of the V2V link into a limit on the SINR of the V2V link; S54. Obtain the matrix channel gain matrix Φ of the V2V links using the same RB according to the channel power gain of the links; S55. Expression for the transmission power of the m-th V2I link transmitter and the k-th V2V transmitter using the f-th resource block RB ; S56. Calculate the average packet loss rate of the V2I link in the C-V2X system after the k-th V2V link reselects the f-th resource block (RB) for transmission according to the expression in step S55 S57. Calculate the probability that the k-th V2V link selects the f-th resource block RB for transmission; In S58, a resource block (RB) selection is completed for all V2V links in each iteration. S56 and S57 are repeated until convergence to obtain the resource allocation scheme for V2I links and V2V links.

10. A C-V2X resource allocation method based on V2I communication requirement analysis according to claim 9, characterized in that, The probability that the k-th V2V link selects the f-th resource block (RB) for transmission is:

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