C-V2X-based wireless resource allocation method

Abstract

The invention relates to a C-V2X-based wireless resource allocation method, which comprises the following steps of: initializing after a triggering resource reselection condition is met, so that a set S1 contains all candidate resources of resource reselection, and sets S2 and S3 are empty sets; excluding candidate resources reserved for other services in the set S1 by using historical data SCI information of the candidate resources to obtain a first resource; in the first resources, excluding candidate resources of which the historical data average RSRP of the resources is higher than a threshold Th1 to obtain second resources; the threshold value Th1 is adjusted step by step, and after the proportion of the screened second resources in the total candidate resources meets a set value, the second resources are placed in a set S2; and the candidate resources in the set S2 are divided into periodic idle resources and non-periodic resources, and the periodic idle resources and the non-periodic resources are combined and placed in the set S3 to serve as resources for transmitting data packets after candidate resource screening is carried out on the periodic idle resources and the non-periodic resources. According to the invention, the probability of resource misjudgment and resource conflict is effectively reduced, the communication reliability is improved, and the wireless resource use efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of cellular vehicle networking, and more particularly to a wireless resource allocation method based on C-V2X. Background Art

[0002] The current wireless resource allocation methods for V2V (vehicle-to-vehicle) communication in the C-V2X (cellular vehicle-to-everything) system are mainly divided into two methods: centralized allocation by base stations and distributed allocation by terminals. The mainstream distributed resource allocation method uses the SB-SPS (perception-based semi-persistent scheduling) algorithm, which estimates the future usage of the resource pool based on the V2V periodic business model, thereby occupying and reserving resources. The distributed resource allocation method supports vehicles to autonomously select and manage resources for communication without any cellular infrastructure support, providing protection for V2V safety applications when cellular network coverage is discontinuous. However, in this mode, the vehicle has a low awareness of the overall wireless resource environment, and there are conflicts when multiple services are selecting wireless resources, resulting in reduced reliability of communication between vehicles. Summary of the invention

[0003] In view of the above analysis, the present invention aims to disclose a wireless resource allocation method based on C-V2X; effectively reduce the probability of resource misjudgment and resource conflict, improve communication reliability, and enhance the efficiency of wireless resource utilization.

[0004] The present invention discloses a wireless resource allocation method based on C-V2X, comprising:

[0005] Initialization: After the triggering resource reselection condition is met, initialization is performed so that set S1 contains all candidate resources for resource reselection, and sets S2 and S3 are empty sets;

[0006] First screening: using the historical data SCI information of the candidate resources to exclude the candidate resources reserved for other services in the set S1 to obtain the first resource;

[0007] Second screening: in the first resources, the candidate resources whose average RSRP of historical data is higher than the threshold Th1 are excluded to obtain the second resource; the threshold Th1 is adjusted step by step, so that the proportion of the screened second resource in the total candidate resources meets the set value, and the second resource is placed in the set S2;

[0008] The third screening: the candidate resources in set S2 are divided into periodic idle resources and non-periodic resources, and the candidate resources are screened separately and then merged and placed in set S3 as resources for transmitting data packets; among them, some resources that have never been reserved in advance are screened out from the periodic idle resources; and some resources with a small S-RSSI mean value of historical data are screened out from the non-periodic resources.

[0009] Furthermore, the conditions for triggering resource reselection are: first, determine whether resource reselection is needed based on the reselection counter RC. When the RC counter is not 0, continue to use the original resources for transmission. After the transmission is completed, RC decreases by 1; when the RC counter is 0, reselect resources according to the 1-p probability; the p probability is the probability of transmission on the original reserved resources.

[0010] Furthermore, in the initialization, it also includes determining a perception window and a selection window; wherein,

[0011] A perception window is used to select the historical time-frequency resource blocks within the first set time window before the current reselection time T, and is used to calculate data including historical data SCI information, average RSRP and S-RSSI mean during the screening process;

[0012] A selection window is used to select a time-frequency resource block of a candidate resource within a second set time window after the current reselection time T; and perform candidate resource exclusion and resource selection in the selection window;

[0013] The set S1 includes the entire set of selection windows.

[0014] Furthermore, the length of the first set time window is 1000ms, and the length of each subframe is 1ms; in the first screening, the candidate resources included in the listening set S1 correspond to the first 1000 subframes of historical data in the perception window, and SCI decoding is performed; according to the decoding result, the candidate resources reserved for other services are excluded to obtain the first resource.

[0015] Furthermore, the average RSRP in the second screening is:

[0016]

[0017] in, Indicates the average RSRP value of the candidate resource corresponding to the xth subframe in the time domain and the yth subchannel in the frequency domain in the first resource at the historical N*100ms time; RSRP (x-i*100,y) Indicates the RSRP value of the candidate resource corresponding to the xi*100th subframe in the time domain and the yth subchannel in the frequency domain at the historical time N*100ms;

[0018] The threshold Th1 value range is [-128dBm, 0dBm].

[0019] Furthermore, the setting value of the proportion of the second resource in the total candidate resources is 20%; and the step length of the step-by-step adjustment threshold Th1 is 3db.

[0020] Furthermore, in the third screening, the screening process of the set S2 includes:

[0021] 1) Determine the busy resources and idle resources in set S2;

[0022] Compare the S-RSSI values ​​of the 10 historical moments before the moment T in the perception window corresponding to the second resource in the set S2 with the S-RSSI threshold Th2. If the S-RSSI value is greater than the threshold, it is determined to be a busy resource. Otherwise, it is determined to be an idle resource.

[0023] 2) Record the number of busy resources N occupy and the number of idle resources N idle , and the array Arr of the location information of the busy resources occupy and an array Arr of free resource location information idle ;

[0024] 3) According to the number of busy resources N occupy 、Number of idle resources idle , and the array Arr of the location information of the busy resources occupy and an array Arr of free resource location information idle The distribution of busy resources and idle resources is determined, and then it is determined whether the resources in the set S2 are periodic resources that are periodically occupied, or non-periodic resources that are non-periodic;

[0025] 4) For periodic resources, after selecting idle resources, K1% of idle resources are screened out as candidate resources, and for non-periodic resources, resource screening is performed based on the S-RSSI mean.

[0026] Furthermore, the resource screening process for non-periodic resources based on the S-RSSI average includes:

[0027] 1) Calculate the S-RSSI mean of the non-periodic resources in set S2;

[0028] 2) Sort the non-periodic resources from large to small according to the S-RSSI mean value;

[0029] 3) Select K2% non-periodic resources with small S-RSSI mean values ​​as candidate resources.

[0030] Furthermore, the calculation method of the S-RSSI mean is:

[0031] 1) According to the idle resource threshold Th2, calculate the number of busy resource occupancy in the perception window

[0032] 2) According to the threshold Th2 of idle resources, calculate the sum of the actual S-RSSI of busy resources

[0033] 3) Based on the number of busy resource occupancy The sum of the actual S-RSSI of the busy resource Calculate the average S-RSSI of the candidate resource at the same historical moment in the perception window

[0034]

[0035] T cr is the temporal position of the candidate resource in the perception window.

[0036] Furthermore, the number of busy resource occupancy for:

[0037]

[0038] in, The initial value of S-RSSI is 0; Tcr-100*i is the time domain position T cr The S-RSSI value corresponding to the historical moment of the same frequency domain position in the perception window;

[0039] The sum of the actual S-RSSI of busy resources for:

[0040]

[0041] in, The initial value of is 0.

[0042] The present invention can achieve one of the following beneficial effects:

[0043] The wireless resource allocation method based on C-V2X disclosed in the present invention can reduce the probability of resource occupation conflicts between periodic services and improve communication reliability. By determining the idle resources of periodic services and estimating the idle resource period, the idle period candidate resources can be allocated to other services that meet the period requirements, thereby improving the utilization rate of wireless resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings are only used for the purpose of illustrating specific embodiments and are not to be considered as limiting the present invention. In the entire drawings, the same reference symbols represent the same components;

[0045] Figure 1 This is a flow chart of a wireless resource allocation method based on C-V2X in an embodiment of the present invention. DETAILED DESCRIPTION

[0046] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used to illustrate the principles of the present invention together with the embodiments of the present invention.

[0047] An embodiment of the present invention discloses a wireless resource allocation method based on C-V2X, such as Figure 1 As shown, including:

[0048] Step 1: Initialization: After the resource reselection triggering condition is met, initialization is performed so that set S1 contains all candidate resources for resource reselection, and sets S2 and S3 are empty sets;

[0049] Step 2, first screening: using the historical data SCI information of the candidate resources to exclude the candidate resources reserved for other services in the set S1 to obtain the first resource;

[0050] Step 3, second screening: in the first resource, exclude the candidate resources whose historical data average RSRP is higher than the threshold Th1 to obtain the second resource; gradually adjust the threshold Th1 so that the proportion of the screened second resource in the total candidate resources meets the set value, and then place the second resource in the set S2;

[0051] Step 4, the third screening; the candidate resources in set S2 are divided into periodic idle resources and non-periodic resources, and the candidate resources are screened separately and then merged and placed in set S3 as resources for transmitting data packets; among them, some resources that have never been reserved in advance are screened out from the periodic idle resources; some resources with a small S-RSSI mean value of historical data are screened out from the non-periodic resources.

[0052] Specifically, the conditions for triggering resource reselection are: first, determine whether resource reselection is needed based on the reselection counter RC. When the RC counter is not 0, continue to use the original resources for transmission. After the transmission is completed, RC decreases by 1; when the RC counter is 0, resource reselection is performed according to the 1-p probability; the p probability is the probability of transmission on the original reserved resources.

[0053] RC is the resource reselection counter, which indicates the number of times the data packets of the periodic services transmitted by the vehicle can be transmitted at the same frequency domain resource. The purpose of setting RC is to allow the periodic services to be transmitted at the same frequency domain location for a period of time, so as to prevent resource selection for each data packet. Frequent resource reselection will lead to large control channel overhead and increase communication delay. The value of the reselection counter RC is different for services with different periods. The RC setting method is as follows.

[0054] When the service cycle is [100ms, 1000ms], the RC value range is [5, 15];

[0055] When the service cycle is [50ms, 100ms], the RC value range is [10, 30];

[0056] When the service cycle is [20ms,50ms], the RC value range is [25,75];

[0057] When the service cycle is [10ms, 20ms], the RC value range is [50, 150];

[0058] The probability P ranges from 0 to 0.8 and can be configured through high-level parameters. The vehicle will continue to transmit on the original reserved resources with probability P and reselect resources with probability 1-P.

[0059] During initialization, the perception window and selection window are also initialized; wherein,

[0060] A perception window is used to select a time-frequency resource block within a first set time window before the current reselection time T; the time-frequency resource block is used to calculate data including SCI information, average RSRP and S-RSSI mean during the screening process;

[0061] A selection window is used to select a time-frequency resource block of a candidate resource within a second set time window after the current reselection time T; candidate resource exclusion and resource selection are performed in the selection window;

[0062] Specifically,

[0063] The length of the first set time window is 1000ms; the perception window range is [T-1000, T-1],

[0064] The length of the second set time window is T2-T1; the selection window range is [T+T1,T+T2];

[0065] Preferably, T1 takes a value range of [1,4], and T2 takes a value range of [20,100].

[0066] During initialization, the set S1 of the entire selection window set includes all candidate resources.

[0067] Specifically,

[0068] In the first screening, the candidate resources included in the listening set S1 correspond to the first 1000 subframes of historical data in the perception window, and SCI decoding is performed; according to the decoding result, the candidate resources reserved for other services are excluded to obtain the first resource.

[0069] SCI information is the control information of the Sidelink link, which includes resource cycle, resource time-frequency position, etc. By correctly decoding the SCI information, it is possible to predict whether the candidate resources in the selection window are reserved by other services through the specific content of the SCI information.

[0070] Specifically, in the second screening, in the first resources, the candidate resources whose average RSRP in historical data is higher than the threshold Th1 are excluded to obtain the second resources;

[0071] The average RSRP (reference signal received power) in the second screening is the average RSRP of the corresponding frequency domain position calculated for the candidate resources in the first resource at the historical N*100ms moment in the perception window.

[0072] Specifically, the calculation formula for average RSRP is:

[0073]

[0074] in, Indicates the average RSRP value of the candidate resource corresponding to the xth subframe in the time domain and the yth subchannel in the frequency domain in the first resource at the historical N*100ms time; RSRP (x-i*100,y) It represents the RSRP value of the candidate resource corresponding to the xi*100th subframe in the time domain and the yth subchannel in the frequency domain in the remaining candidate resources at the historical time N*100ms. The average RSRP is actually to find the linear mean of RSRP at a time interval of 100ms, and N is generally 10.

[0075] 3GPP defines the RSRP threshold Th1 as ranging from [-128dBm, 0dBm], and stipulates that the threshold is a packet priority function, and the two parameters it depends on are the packet priority of the resource previously reserved and the packet priority to be sent. Compare the RSRP mean value obtained above with the threshold Th1, exclude the candidate resources that are greater than this threshold, and continue to use the candidate resources that are less than this threshold as the second resource.

[0076] Since the level of threshold Th1 will affect the number of second resources, in order to obtain sufficient second resources, the proportion of second resources in the total candidate resources is set to 20%; when the proportion of second resources in the window set S1 does not meet 20%, the threshold Th1 is gradually increased, and the second screening is performed in a loop until the proportion meets 20%, and the second resources are placed in the set S2; wherein the step size of gradually increasing the threshold Th1 is 3db.

[0077] The second resources placed in the set S2 still include occupied resources and unoccupied resources, which need to be further screened.

[0078] Specifically, in the third screening, the screening process of set S2 includes:

[0079] 1) Determine the busy resources and idle resources in set S2;

[0080] Compare the S-RSSI values ​​of the 10 historical moments before the moment T in the perception window corresponding to the second resource in the set S2 with the S-RSSI threshold Th2. If the S-RSSI value is greater than the threshold, it is determined to be a busy resource. Otherwise, it is determined to be an idle resource.

[0081] Specifically, the S-RSSI threshold Th2 is close to and greater than the noise power of any bandwidth resource block in the idle state.

[0082] The noise power of any bandwidth resource block in the idle state is calculated as follows:

[0083] RSSI (Received Signal Strength Indicator) is defined in the 3GPP protocol as the average power of all signals within the receiving broadband, including pilot signals, data signals, neighboring interference signals and noise signals. In the no-load state, only the influence of noise is considered. The thermal noise power within the unit bandwidth is directly related to the temperature and system bandwidth. The calculation formula for the noise power within the unit bandwidth is as follows:

[0084] P noise =10log(K*T*B)

[0085] Where P noise Indicates the noise power per unit bandwidth, in dBm; K is the Boltzmann constant, in 1.38*10 -23 , unit is J / K; T is temperature, here the room temperature is 290; B is system bandwidth, unit is Hz, here it is 1Hz. Substituting the above values ​​into the above formula, we can get the noise power within the unit system bandwidth as -174dBm / Hz.

[0086] Therefore, the noise power calculation formula for any bandwidth resource block in the idle state is as follows:

[0087] P noise =-174+10log(B)+Th noise

[0088] Among them Th noise is the noise coefficient, in db; B is the frequency domain bandwidth. Substitute the bandwidth occupied by the resource block into the above formula to solve the noise power of resource blocks of different bandwidth sizes in the idle state to determine the S-RSSI threshold Th2 of the idle resource block.

[0089] 2) Record the number of busy resources N occupy and the number of idle resources N idle , and the array Arr of the location information of the busy resources occupy and an array Arr of free resource location information idle ;

[0090] 3) According to the number of busy resources N occupy 、Number of idle resources idle , and the array Arr of the location information of the busy resources occupy and an array Arr of free resource location information idleThe distribution of the determined busy resources and idle resources is determined to determine whether the resources in the set S2 are periodic resources that are periodically occupied or non-periodic resources that are non-periodic;

[0091] In a more specific scheme, the following method for determining cycle resources is given;

[0092] a. Establish the number of busy resources N occupy and resource occupancy cycle regularity table;

[0093]

[0094] The source occupation periodicity table shows that in 100ms of 10 historical moments, when:

[0095] N occupy =10, there are 10 busy resources in the perception window, and the resource occupancy period cannot be determined in 10 historical moments;

[0096] N occupy =6 / 7 / 8 / 9, the resource occupation period must be less than 200ms and greater than 100ms. Similarly, the resource occupation period cannot be determined.

[0097] N occupy =5, it can be determined that the periodic resources with a period of 200ms are occupied;

[0098] N occupy =4, it can be determined that the periodic resources with a period of 300ms are occupied;

[0099] N occupy =3, two periodic resources with occupation periods of 400ms and 300ms can be determined;

[0100] N occupy =2, six periodic resources with occupation periods of 400ms, 500ms, 600ms, 700ms, 800ms and 900ms can be determined;

[0101] N occupy =1, it can be any periodic resource with a period greater than 500ms, but the specific period occupied by the resource cannot be determined.

[0102] b. Based on the number of busy resources N occupy Determine the periodic resources and the periodic length of the resources using the resource occupation periodic rule table and periodic rule judgment formula;

[0103] The formula for judging the periodicity is a n =a1+(n-1)d; where a1 is the array Arr of the location information of the busy resources occupyThe location of the first busy resource in a n Arr is the array of location information of busy resources occupy The position of the nth busy resource in the occupy Determined available period values ​​in the periodic law table;

[0104] The array Arr of the location information of the busy resources occupy Substitute the determined available period value into the period rule judgment formula, and find out d that makes all busy resource positions satisfy the formula. Then determine that the candidate resource is a period resource and the period is the number of ms corresponding to d.

[0105] 4) For periodic resources, after selecting idle resources, K1% of idle resources are screened out as candidate resources, and for non-periodic resources, resource screening is performed based on the S-RSSI mean.

[0106] Preferably, in the process of determining idle resources, according to the array Arr of the location information of busy resources occupy The location and resource occupancy period of the resource are used to predict whether the resource is idle at time T;

[0107] For all the predicted idle resources at time T, K1%=10% are taken as candidate resources.

[0108] Specifically, the resource screening process for non-periodic resources based on the S-RSSI average includes:

[0109] 1) Calculate the S-RSSI mean of the non-periodic resources in set S2;

[0110] 2) Sort the non-periodic resources from large to small according to the S-RSSI mean value;

[0111] 3) Select K2% non-periodic resources with small S-RSSI mean values ​​as candidate resources;

[0112] The preferred K2%=10%.

[0113] Preferably, in this embodiment, an improved S-RSSI mean value calculation method is used to obtain the S-RSSI mean value: specifically including:

[0114] 1) According to the idle resource threshold Th2, calculate the number of busy resource occupancy in the perception window

[0115] Busy resource usage times for:

[0116]

[0117] in, The initial value of S-RSSI is 0; Tcr-100*i is the time domain position T cr The S-RSSI value corresponding to the historical moment of the same frequency domain position in the perception window.

[0118] 2) According to the threshold Th2 of idle resources, calculate the sum of the actual S-RSSI of busy resources

[0119] The sum of the actual S-RSSI of busy resources for:

[0120]

[0121] in, The initial value of is 0.

[0122] 3) Based on the number of busy resource occupancy The sum of the actual S-RSSI of the busy resource Calculate the average S-RSSI of the candidate resource at the same historical moment in the perception window

[0123]

[0124] After screening the periodic idle resources and non-periodic resources in set S2, K1% and K2% of the resources are combined and placed in set S3 as resources for transmitting data packets; the candidate resources in set S3 are screened layer by layer, with less interference and a very low probability of being reserved. Then, candidate resources are randomly selected from set S3 for transmitting data packets, and the value of the reselection counter RC is reinitialized, and then the data continues to occupy this resource position until the resource reselection conditions are met again.

[0125] In summary, the wireless resource allocation method based on C-V2X disclosed in the embodiment of the present invention can reduce the probability of resource occupation conflicts between periodic services and improve communication reliability. By determining the idle resources of periodic services and estimating the idle resource period, the idle period candidate resources can be allocated to other services that meet the period requirements, thereby improving the utilization rate of wireless resources.

[0126] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A wireless resource allocation method based on C-V2X, characterized in that: include: Initialization: After the triggering resource reselection condition is met, initialization is performed so that set S1 contains all candidate resources for resource reselection, and sets S2 and S3 are empty sets; First screening: using the historical data SCI information of the candidate resources to exclude the candidate resources reserved for other services in the set S1 to obtain the first resource; Second screening: in the first resources, the candidate resources whose average RSRP of historical data is higher than the threshold Th1 are excluded to obtain the second resource; the threshold Th1 is adjusted step by step, so that the proportion of the screened second resource in the total candidate resources meets the set value, and the second resource is placed in the set S2; The third screening: the candidate resources in set S2 are divided into periodic idle resources and non-periodic resources, and the candidate resources are screened separately and then merged and placed in set S3 as resources for transmitting data packets; among them, some resources that have never been reserved in advance are screened out from the periodic idle resources; Select some resources with small S-RSSI average values ​​in historical data from non-periodic resources.

2. The C-V2X-based wireless resource allocation method according to claim 1, characterized in that: The conditions for triggering resource reselection are as follows: first, determine whether resource reselection is needed based on the reselection counter RC. When the RC counter is not 0, continue to use the original resources for transmission. After the transmission is completed, RC decreases by 1; when the RC counter is 0, reselect resources according to the 1-p probability; the p probability is the probability of transmission on the original reserved resources.

3. The C-V2X-based wireless resource allocation method according to claim 2, characterized in that: During initialization, it also includes determining the perception window and the selection window; wherein, A perception window is used to select the historical time-frequency resource blocks within the first set time window before the current reselection time T, and is used to calculate data including historical data SCI information, average RSRP and S-RSSI mean during the screening process; A selection window is used to select a time-frequency resource block of a candidate resource within a second set time window after the current reselection time T; and perform candidate resource exclusion and resource selection in the selection window; The set S1 includes the entire set of selection windows.

4. The C-V2X-based wireless resource allocation method according to claim 3, characterized in that: The length of the first set time window is 1000ms, and the length of each subframe is 1ms; in the first screening, the candidate resources included in the listening set S1 correspond to the first 1000 subframes of historical data in the perception window, and SCI decoding is performed; according to the decoding result, the candidate resources reserved for other services are excluded to obtain the first resource.

5. The C-V2X-based wireless resource allocation method according to claim 4, characterized in that: The average RSRP in the second screening is: in, Indicates the average RSRP value of the candidate resource corresponding to the xth subframe in the time domain and the yth subchannel in the frequency domain in the first resource at the historical N*100ms time; RSRP (x-i*100,y) Indicates the RSRP value of the candidate resource corresponding to the xi*100th subframe in the time domain and the yth subchannel in the frequency domain at the historical time N*100ms; The threshold Th1 value range is [-128dBm, 0dBm].

6. The C-V2X-based wireless resource allocation method according to claim 5, characterized in that: The setting value of the proportion of the second resource in the total candidate resources is 20%; the step length of gradually increasing the threshold Th1 is 3db.

7. The C-V2X-based wireless resource allocation method according to claim 5, characterized in that: In the third screening, the screening process for set S2 includes: 1) Determine the busy resources and idle resources in set S2; Compare the S-RSSI values ​​of the 10 historical moments before the moment T in the perception window corresponding to the second resource in the set S2 with the S-RSSI threshold Th2. If the S-RSSI value is greater than the threshold, it is determined to be a busy resource. Otherwise, it is determined to be an idle resource. 2) Record the number of busy resources N occupy and the number of idle resources N idle , and the array Arr of the location information of the busy resources occupy and an array Arr of free resource location information idle ; 3) According to the number of busy resources N occupy 、Number of idle resources idle , and the array Arr of the location information of the busy resources occupy and an array Arr of free resource location information idle The distribution of busy resources and idle resources is determined, and then it is determined whether the resources in the set S2 are periodic resources that are periodically occupied, or non-periodic resources that are non-periodic; 4) For periodic resources, after selecting idle resources, K1% of idle resources are screened out as candidate resources, and for non-periodic resources, resource screening is performed based on the S-RSSI mean.

8. The C-V2X-based wireless resource allocation method according to claim 7, characterized in that: The resource screening process for non-periodic resources based on the S-RSSI average includes: 1) Calculate the S-RSSI mean of the non-periodic resources in set S2; 2) Sort the non-periodic resources from large to small according to the S-RSSI mean value; 3) Select K2% non-periodic resources with small S-RSSI mean values ​​as candidate resources.

9. The C-V2X-based wireless resource allocation method according to claim 8, characterized in that: The calculation method of S-RSSI mean is: 1) According to the idle resource threshold Th2, calculate the number of busy resource occupancy in the perception window 2) According to the threshold Th2 of idle resources, calculate the sum of the actual S-RSSI of busy resources 3) Based on the number of busy resource occupancy The sum of the actual S-RSSI of the busy resource Calculate the average S-RSSI of the candidate resource at the same historical moment in the perception window T cr is the temporal position of the candidate resource in the perception window.

10. The C-V2X-based wireless resource allocation method according to claim 8, characterized in that: Busy resource usage times for: in, The initial value of S-RSSI is 0; Tcr-100*i is the time domain position T cr The S-RSSI value corresponding to the historical moment of the same frequency domain position in the perception window; The sum of the actual S-RSSI of busy resources for: in, The initial value of is 0.

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