Synchronization Method and Apparatus for In-Vehicle Gigabit Ethernet

Abstract

This invention discloses a synchronization method and apparatus for in-vehicle gigabit Ethernet. The method includes: S1: configuring N search boxes within a synchronization period T, performing sliding correlation calculations using a local synchronization sequence and a received symbol sequence within each search box to obtain correlation calculation results, wherein the length of the search box is the same as the length of the received symbol sequence, the length of the local synchronization sequence is less than the length of the received symbol sequence, and N≥2; S2: segmenting and sorting the correlation calculation results of each search box to obtain the peak value of each segment, and filtering out the top P peak values ​​in order of size, then confirming whether the maximum peak value of each search box is valid by comparing the maximum peak value with noise and the Pth peak value; when the maximum peak value of at least two search boxes is valid, proceeding to S3, otherwise considering synchronization failure; S3: performing position verification on at least two valid maximum peak values; if certain conditions are met, synchronization is considered successful, otherwise considering synchronization failure.

Description

Technical Field

[0001] This invention relates to the field of vehicle communication technology, and in particular to a synchronization method and apparatus for vehicle-mounted gigabit Ethernet. Background Technology

[0002] Automotive Ethernet refers to a network system that uses Ethernet technology for data transmission and communication within a vehicle. It employs the Ethernet protocol and physical interfaces to provide high-speed, reliable data transmission capabilities, connecting various electronic control units, sensors, actuators, and infotainment systems within the vehicle. Its primary uses are for communication and data exchange between different systems within the vehicle, such as data transmission between vehicle control units, real-time sensor data collection and processing, and interconnection and distribution of entertainment content within infotainment systems. It also supports various application scenarios, such as in-vehicle entertainment systems, vehicle diagnostic systems, and driver assistance systems.

[0003] Gigabit automotive Ethernet offers high bandwidth, supports various applications and functions, and boasts robust and sustainable update capabilities, making it increasingly important to automakers.

[0004] Gigabit automotive Ethernet physical layer primarily has three modes: synchronization, training, and data transmission. Synchronization is the first step in establishing a link between the transmitter and receiver. If the synchronization success rate is low, a connection cannot be established quickly and data cannot be transmitted, resulting in an increased time for the system to enter operational status.

[0005] Therefore, fast and reliable synchronization is crucial for Gigabit Ethernet.

[0006] Existing synchronization methods that use local sequences and received symbols for correlation operations have the following problems:

[0007] (1) The computational complexity of performing full-length correlation operations between the local sequence and the received symbol is relatively large;

[0008] (2) If the results obtained from related calculations are not processed correctly, false alarms and missed alarms are likely to occur.

[0009] Current automotive gigabit Ethernet synchronization technologies mostly employ a full-sequence correlation method that compares peak values ​​one by one. This method involves a large amount of computation, many steps, and consumes a great deal of hardware resources. Summary of the Invention

[0010] To address the aforementioned technical problems, this invention proposes a method for partial correlation and block peak extraction, which has the advantages of low computational load, fewer steps, and less hardware resource requirement compared to existing technologies.

[0011] To achieve the above objectives, the technical solution of the present invention provides a synchronization method for in-vehicle gigabit Ethernet, comprising the following steps: S1 Synchronization Search: N search boxes are configured within a synchronization period T. In each search box, a local synchronization sequence of length M is used to perform sliding correlation calculation with the received symbol sequence to obtain the correlation calculation result. The length of the search box is consistent with the length of the received symbol sequence. The local synchronization sequence is generated by a local sequence generator and its length M is less than the length of the received symbol sequence, and N≥2; S2 Peak Comparison: The correlation calculation result of each search box is segmented and sorted to obtain the peak value of each segment. The top P peak values ​​are selected in order of size. Then, the maximum peak value of the corresponding search box is compared with the noise and the Pth peak value to confirm whether the maximum peak value of each search box is valid. When the maximum peak value of at least two search boxes is valid, proceed to step S3; otherwise, synchronization is considered to have failed; S3 Position Verification: The position of at least two valid maximum peak values ​​obtained in step S2 is verified. If the position relationship of at least two valid maximum peak values ​​meets the conditions, synchronization is considered to have succeeded; otherwise, synchronization is considered to have failed.

[0012] Further, in step S1, the relevant calculation is as follows:

[0013]

[0014] Where P(n) is the correlation calculation result, R(i) is the received symbol sequence, S(i) is the local synchronization sequence generated by the local sequence generator, ABS is the absolute value operation, and M is the length of the local synchronization sequence.

[0015] Further, step S2 specifically includes: S21: For each search box, the correlation values ​​obtained through correlation calculation are segmented, with each segment having a length of K. A peak value is selected from the K correlation values ​​in each segment, and the peak value and its corresponding position are recorded; S22: The peak values ​​in each segment are sorted in descending order, and only the first P peak values ​​and their corresponding positions are retained; S23: The noise power is calculated by excluding the first P peak values ​​obtained in step S22 from all correlation values ​​and averaging the remaining correlation values; S24: Based on the noise power obtained in step S23 and the Pth peak value obtained in step S22, the maximum peak value among all correlation values ​​is confirmed.

[0016] Further, in step S24, the maximum peak power is confirmed to be valid when the maximum peak power satisfies the following formula:

[0017] Power_MAX>Power_noise*Threshold_Peak_Noise;

[0018] Power_MAX>Power_Pth*Threshold_Peak_Pth;

[0019] Wherein, Power_MAX represents the maximum peak power, Power_noise represents the noise power, Power_Pth represents the Pth peak power in descending order, Threshold_Peak_Noise represents the threshold ratio between the maximum peak power and the noise power, and Threshold_Peak_Pth represents the threshold ratio between the maximum peak power and the Pth peak power in descending order.

[0020] Further, step S3 specifically includes: S31: sending the position results of at least two valid maximum peaks obtained in step S2 into the position verification module, and obtaining the difference between the maximum peak positions by subtracting the maximum peak positions pairwise and taking the modulus of 255;

[0021] S32: Count the number of values ​​in diff_poss that are less than or equal to 1. If the value is greater than or equal to 1, the synchronization is considered successful; otherwise, the synchronization is considered to have failed.

[0022] Further, in step S1, when the receiver is a MASTER, the formula for generating the local synchronization sequence is: p M (x)=x 8 +x 4 +x 3 +x 2 +1; When the receiver is a SLAVE, the formula for generating the local synchronization sequence is: p MS (x)=x 8 +x 6 +x 5 +x 4 +1.

[0023] Furthermore, in step S1, N=3 search windows are configured within the synchronization period T, each search window has a length of 255, and the length of the local synchronization sequence is M=64.

[0024] The technical solution of the present invention also provides a synchronization device for in-vehicle gigabit Ethernet, which includes the following modules: a synchronization search module: configured with N search boxes within a synchronization period T, and performing sliding correlation calculations on a local synchronization sequence of length M and a received symbol sequence within each search box to obtain correlation calculation results, wherein the length of the search box is the same as the length of the received symbol sequence, the local synchronization sequence is generated by a local sequence generator and its length M is less than the length of the received symbol sequence, and N≥2; a peak comparison module: sorting the correlation calculation results of each search box into segments to obtain the peak value of each segment, and filtering out the top P peak values ​​in order of size, and then confirming whether the maximum peak value of each search box is valid by comparing the maximum peak value of the corresponding search box with the noise and the Pth peak value. When the maximum peak values ​​of at least two search boxes are valid, the position verification module further performs position verification; otherwise, the synchronization is considered to have failed; a position verification module: performing position verification when the peak comparison module obtains at least two valid maximum peak values. If the positional relationship of at least two valid maximum peak values ​​meets the conditions, the synchronization is considered to have succeeded; otherwise, the synchronization is considered to have failed. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a basic flowchart of the synchronization method of the present invention;

[0027] Figure 2 This is a schematic diagram of the synchronous search module of the present invention;

[0028] Figure 3 This is a schematic diagram of the peak comparison module of the present invention;

[0029] Figure 4 This is a schematic diagram of the M=64 related results of the present invention. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] To further simplify computation and reduce hardware resources while ensuring reliable and fast synchronization, this invention provides an in-vehicle gigabit Ethernet synchronization method.

[0032] This method includes three processing modules: synchronous search, peak comparison, and position verification.

[0033] The synchronous search module is used to perform correlation operations between the local sequence and the received data symbols. A local sequence generator generates a symbol sequence identical to that of the transmitter, and the sequence length can be freely set. In this invention, a local sequence of a certain length is sufficient to obtain the ideal correlation peak. A fixed-length search window is set, and within the search window, the local sequence of the fixed length is used to perform correlation summation with the received symbols, yielding a correlation result with a length equal to the search window size. The correlation results are then sorted from largest to smallest. To speed up the sorting process and reduce computation, a block sorting method is used, where a maximum value is determined every K correlation values, and the maximum value and its corresponding position are extracted and placed into the sorted array.

[0034] The peak comparison module is used to compare the peak value with noise and a larger value. The noise is calculated by summing and averaging the correlation values ​​after excluding the largest P peak values ​​and their left and right adjacent correlation values. In addition, by comparing the relative relationship between the largest peak value and the Pth peak value, it is confirmed that the ratio of the largest peak value to the Pth peak value is greater than a threshold value, thus confirming the validity of the peak value and storing the peak value and its corresponding position.

[0035] The position verification module divides the received signal into three consecutive search windows, each with equal data length, and performs peak search and peak comparison for each window. After peak comparison, multiple peak positions are obtained. Position verification is performed on these multiple peaks. If the relative relationship between the peak positions meets the conditions, the peaks are considered valid, and the final synchronization result is confirmed.

[0036] like Figure 1 As shown, this invention proposes a vehicle-mounted gigabit Ethernet synchronization method, which includes the following steps: synchronization search, peak value comparison, and position verification.

[0037] Among them, see Figure 2 The synchronous search configures N=3 search windows within the synchronization period T, and the length of each search window is 255; the search window uses a local sequence of length M for sliding correlation.

[0038] In an optional embodiment, M is configured according to the system hardware resource capabilities. To simplify the computation, M is generally less than 255.

[0039] The specific calculations are as follows:

[0040]

[0041] Where P(n) is the correlation calculation result, R(i) is the received symbol sequence, S(i) is the local synchronization sequence generated by the local sequence generator, ABS is the absolute value operation, and M is the length of the local synchronization sequence.

[0042] According to the automotive gigabit Ethernet 1000BASE-T1 protocol, the formula for locally generated sequences is as follows:

[0043] If the receiver is MASTER: p M (x)=x 8 +x 4 +x 3 +x 2 +1

[0044] If the receiver is a SLAVE: p MS (x)=x 8 +x 6 +x 5 +x 4 +1

[0045] The number of multiply-accumulate units required for related calculations is directly related to the size of M; the larger M is, the more multiply-accumulate units are required.

[0046] Furthermore, the peak comparison module performs peak comparison and stores the correlation values ​​calculated in the sliding correlation. See also Figure 3 The specific steps are as follows:

[0047] (1) First, the correlation values ​​with a length of 255 obtained from the correlation calculation are divided into segments, each segment having a length of K. In each segment, a peak value is selected from the K correlation values, and the peak value and the corresponding position of the peak value are recorded.

[0048] (2) Sort the peak values ​​obtained for each segment length in descending order, and retain only the first P peak values ​​and their corresponding positions after sorting.

[0049] (3) The noise power is calculated based on the correlation value with a length of 255. The calculation method is as follows: the first P peak values ​​obtained in step 2 are excluded from the correlation value with a length of 255, and then the average value of the remaining correlation value is taken.

[0050] (4) Confirm the maximum peak value based on the noise power obtained in step (3) and the Pth peak value obtained in step (2):

[0051] Power_MAX>Power_noise*Threshold_Peak_Noise;

[0052] Power_MAX>Power_Pth*Threshold_Peak_Pth;

[0053] In the above formula, Power_MAX represents the maximum peak power, Power_noise represents the noise power, Power_Pth represents the Pth peak power in descending order, Threshold_Peak_Noise represents the threshold ratio between the maximum peak power and the noise power, and Threshold_Peak_Pth represents the threshold ratio between the maximum peak power and the Pth peak power in descending order.

[0054] The maximum peak value that satisfies the above formula is considered the valid maximum peak value, and the position corresponding to the maximum peak value is stored.

[0055] Furthermore, when there are at least two valid maximum peaks, the peak verification module performs position verification by searching and comparing the positions of the maximum peaks obtained from the three search windows. If the position of the maximum peak meets the requirements, it is considered that the maximum peak has been found and the synchronization is successful.

[0056] The specific verification steps are as follows:

[0057] Subtract the two adjacent maximum peak locations and perform modulo 255 operations, i.e.:

[0058] diff_pos=[V_pos[3]-V_pos[2]V_pos[3]-V_pos[1], V_pos[2]-V_pos[1]]

[0059] diff_pos = diff_pos % 255;

[0060] Count the number of values ​​in diff_pos that are less than or equal to 1, and denote it as Num;

[0061] If Num >= 1, then synchronization is considered successful; otherwise, synchronization is considered to have failed. Specific implementation examples:

[0063] The receiver is configured as the MASTER, and its communication counterpart is the SLAVE. First, the MASTER continuously sends synchronization sequences. After receiving the synchronization sequence sent by the MASTER, the SLAVE sends a synchronization sequence in response to the MASTER. In this embodiment, the receiver, acting as the MASTER, needs to be able to detect the synchronization sequences sent by the SLAVE. In this embodiment, the receiver generates a local synchronization sequence and correlates it with the received symbols. The correlation formula is:

[0064]

[0065] In this embodiment, M is set to 64; simulation verification shows that a reliable peak value can be obtained with M=64, as shown in the following results. Figure 4 As shown. Compared to using the full sequence M=255, the computational cost is 1 / 4 of that of M=255, and the required hardware resources are also reduced to 1 / 4 of that of M=255.

[0066] The receiver then compares and sorts the correlation results. In this embodiment, the correlation results are segmented, with each segment having a length of K=4. The maximum value in each segment is found and sorted from largest to smallest. The top P largest peaks and their positions are recorded. In this embodiment, P=6. The top P largest peaks are excluded from all 255 correlation results. The results are then summed and averaged to calculate the noise power. The maximum peak value is compared with the noise power and the Pth peak value in the descending order. The maximum peak value that satisfies the formula is considered a valid peak value, and the maximum peak value and its corresponding position are recorded.

[0067] Power_MAX>Power_noise*Threshold_Peak_Noise;

[0068] Power_MAX>Power_Pth*Threshold_Peak_Pth;

[0069] In this embodiment, Threshold_Peak_Noise = 5, Threshold_Peak_Pth = 3.

[0070] Synchronous searching and peak comparison are performed within three search windows. The location of the found maximum peak is sent to the location verification module. The difference between the maximum peak locations is obtained by subtracting each pair of maximum peak locations and taking the modulo 255. The number of values ​​less than or equal to 1 in diff_pos is counted. If the value is greater than or equal to 1, the synchronization is considered successful; otherwise, the synchronization is considered to have failed.

[0071] Understandably, the length M of the local synchronization sequence can also be 32, 128, or even 255, but understandably, the larger M is, the higher the computational complexity.

[0072] In addition, the peak comparison module only compares relevant peak values ​​with noise, not with larger values. This reduces computational load and increases processing speed, but it increases the likelihood of false alarms or missed alarms.

[0073] In the above embodiment, the number of search windows N=3. It can be understood that the number of search windows can be increased or decreased.

[0074] In an embodiment of the present invention, a synchronization method for in-vehicle gigabit Ethernet is provided, comprising the following steps: S1 Synchronization Search: N search boxes are configured within a synchronization period T. In each search box, a local synchronization sequence of a certain length M is used to perform sliding correlation calculation with the received symbol sequence to obtain the correlation calculation result. The length of the search box is consistent with the length of the received symbol sequence. The local synchronization sequence is generated by a local sequence generator and its length is less than the length of the received symbol sequence, and N≥2; S2 Peak Comparison: The correlation calculation result of each search box is segmented and sorted to obtain the peak value of each segment. The top P peak values ​​are selected in order of size. Then, the maximum peak value of the corresponding search box is compared with the noise and the Pth peak value to confirm whether the maximum peak value of each search box is valid. When the maximum peak value of at least two search boxes is valid, proceed to step S3; otherwise, synchronization is considered to have failed; S3 Position Verification: The position of at least two valid maximum peak values ​​obtained in step S2 is verified. If the position relationship of at least two valid maximum peak values ​​meets the conditions, synchronization is considered to have succeeded; otherwise, synchronization is considered to have failed.

[0075] Further, in step S1, the relevant calculation is as follows:

[0076]

[0077] Where P(n) is the correlation calculation result, R(i) is the received symbol sequence, S(i) is the local synchronization sequence generated by the local sequence generator, ABS is the absolute value operation, and M is the length of the local synchronization sequence.

[0078] Further, step S2 specifically includes: S21: For each search box, the correlation values ​​obtained through correlation calculation are segmented, with each segment having a length of K. A peak value is selected from the K correlation values ​​in each segment, and the peak value and its corresponding position are recorded; S22: The peak values ​​in each segment are sorted in descending order, and only the first P peak values ​​and their corresponding positions are retained; S23: The noise power is calculated by excluding the first P peak values ​​obtained in step S22 from all correlation values ​​and averaging the remaining correlation values; S24: Based on the noise power obtained in step S23 and the Pth peak value obtained in step S22, the maximum peak value among all correlation values ​​is confirmed.

[0079] Further, in step S24, the maximum peak power is confirmed to be valid when the maximum peak power satisfies the following formula:

[0080] Power_MAX>Power_noise*Threshold_Peak_Noise;

[0081] Power_MAX>Power_Pth*Threshold_Peak_Pth;

[0082] Wherein, Power_MAX represents the maximum peak power, Power_noise represents the noise power, Power_Pth represents the Pth peak power in descending order, Threshold_Peak_Noise represents the threshold ratio between the maximum peak power and the noise power, and Threshold_Peak_Pth represents the threshold ratio between the maximum peak power and the Pth peak power in descending order.

[0083] Further, step S3 specifically includes: S31: sending the position results of at least two valid maximum peaks obtained in step S2 into the position verification module, and obtaining the difference between the maximum peak positions by subtracting the maximum peak positions pairwise and taking the modulus of 255;

[0084] S32: Count the number of values ​​in diff_poss that are less than or equal to 1. If the value is greater than or equal to 1, the synchronization is considered successful; otherwise, the synchronization is considered to have failed.

[0085] Further, in step S1, when the receiver is a MASTER, the formula for generating the local synchronization sequence is: p M (x)=x 8 +x 4 +x 3 +x 2 +1; When the receiver is a SLAVE, the formula for generating the local synchronization sequence is: p MS (x)=x 8 +x 6 +x 5 +x 4 +1.

[0086] Furthermore, in step S1, N=3 search windows are configured within the synchronization period T, each search window has a length of 255, and the length of the local synchronization sequence is M=64.

[0087] In another embodiment of the present invention, a synchronization device for in-vehicle gigabit Ethernet is also provided, comprising the following modules: a synchronization search module: configured to configure N search boxes within a synchronization period T, and to perform sliding correlation calculations on a local synchronization sequence of a certain length M and the received symbol sequence within each search box to obtain correlation calculation results, wherein the length of the search box is consistent with the length of the received symbol sequence, the local synchronization sequence is generated by a local sequence generator and its length is less than the length of the received symbol sequence, and N≥2; a peak comparison module: sorting the correlation calculation results of each search box into segments to obtain the peak value of each segment, and filtering out the first P peak values ​​in order of size, and then confirming whether the maximum peak value of each search box is valid by comparing the maximum peak value of the corresponding search box with the noise and the Pth peak value; when the maximum peak value of at least two search boxes is valid, the position verification module further performs position verification, otherwise the synchronization is considered to have failed; a position verification module: performing position verification when the peak comparison module obtains at least two valid maximum peak values; if the position relationship of at least two valid maximum peak values ​​meets the conditions, the synchronization is considered to have succeeded, otherwise the synchronization is considered to have failed.

[0088] The beneficial technical effects of the technical solution of the present invention are as follows:

[0089] This invention achieves ideal correlation peaks by using a local sequence with a length shorter than the length of the received symbol sequence, which reduces computational load and hardware consumption compared to using full sequence correlation.

[0090] This invention reduces the probability of false alarms by comparing relevant peak values ​​with noise and larger values.

[0091] This invention reduces the probability of missynchronization and improves synchronization accuracy by performing position verification on the maximum peak position obtained after searching and comparing three search windows.

[0092] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A synchronization method for in-vehicle gigabit Ethernet, characterized in that, Includes the following steps: S1 Synchronization Search: Within the synchronization period T, N search boxes are configured, each with a length of 255. Within each search box, a sliding correlation calculation is performed using a local synchronization sequence of length M and the received symbol sequence to obtain the correlation calculation result. The length of the search box is the same as the length of the received symbol sequence. The local synchronization sequence is generated by the local sequence generator and its length M is less than the length of the received symbol sequence, and N≥2. S2 Peak Comparison: The relevant values ​​calculated for each search box are segmented and sorted to obtain the peak value of each segment. The top P peak values ​​are then selected in order of size. The top P peak values ​​are excluded from all relevant values, and the average value of the remaining relevant values ​​is calculated to obtain the noise power. The maximum peak value of the corresponding search box is then compared with the noise and the Pth peak value to confirm whether the maximum peak value of each search box is valid. If the maximum peak values ​​of at least two search boxes are valid, proceed to step S3; otherwise, synchronization is considered to have failed. The maximum peak power is confirmed to be valid when the following formula is satisfied: Power_MAX>Power_noise*Threshold_Peak_Noise; Power_MAX>Power_Pth* Threshold_Peak_Pth; Wherein, Power_MAX represents the maximum peak power, Power_noise represents the noise power, Power_Pth represents the Pth peak power in descending order, Threshold_Peak_Noise represents the threshold ratio between the maximum peak power and the noise power, and Threshold_Peak_Pth represents the threshold ratio between the maximum peak power and the Pth peak power in descending order. S3 Position Verification: Perform position verification on at least two valid maximum peaks obtained in step S2. If the positional relationship between at least two valid maximum peaks meets the conditions, the synchronization is considered successful; otherwise, the synchronization is considered to have failed. Step S3 specifically includes: S31: Send the position results of at least two valid maximum peaks obtained in step S2 into the position verification module. By subtracting the maximum peak positions pairwise and taking the modulus of 255, the difference between the maximum peak positions is obtained as diff_poss. S32: Count the number of values ​​in diff_poss that are less than or equal to 1. If the value is greater than or equal to 1, the synchronization is considered successful; otherwise, the synchronization is considered to have failed.

2. The method according to claim 1, characterized in that, In step S1, the relevant calculations are as follows: ； Where P(n) is the correlation calculation result, R(i) is the received symbol sequence, S(i) is the local synchronization sequence generated by the local sequence generator, ABS is the absolute value operation, and M is the length of the local synchronization sequence.

3. The method according to claim 1, characterized in that, Step S2 specifically includes: S21: For each search box, the relevant values ​​obtained through relevant calculations are segmented, and the length of each segment is K. A peak value is selected from the K relevant values ​​in each segment, and the peak value and the corresponding position of the peak value are recorded. S22: Sort the peak values ​​in each relevant value segment in descending order, and retain only the first P peak values ​​after sorting and their corresponding positions; S23: The noise power is calculated by excluding the first P peak values ​​obtained in step S22 from all the correlation values ​​and averaging the remaining correlation values. S24: Based on the noise power obtained in step S23 and the Pth peak value obtained in step S22, confirm the maximum peak value among all relevant values.

4. The method according to claim 1, characterized in that, In step S1, when the receiver is a MASTER, the formula for generating the local synchronization sequence is: p M (x)=x 8 +x 4 +x 3 +x 2 + 1； When the receiver is a SLAVE, the formula for generating the local synchronization sequence is: p MS (x)=x 8 +x 6 +x 5 +x 4 + 1.

5. The method according to claim 1, characterized in that, In step S1, N=3 search boxes are configured within the synchronization period T, and the length of the local synchronization sequence is M=64.

6. A synchronization device for in-vehicle gigabit Ethernet, characterized in that, Includes the following modules: Synchronization Search Module: Used to configure N search boxes within a synchronization period T. Each search box has a length of 255. Within each search box, a sliding correlation calculation is performed using a local synchronization sequence of length M and the received symbol sequence to obtain the correlation calculation result. The length of the search box is the same as the length of the received symbol sequence. The local synchronization sequence is generated by the local sequence generator and its length M is less than the length of the received symbol sequence, and N≥2. Peak Comparison Module: This module is used to segment and sort the relevant values ​​of each search box to obtain the peak value of each segment, and filter out the top P peak values ​​in order of size. By excluding the top P peak values ​​from all relevant values ​​and averaging the remaining relevant values, the noise power is calculated. Then, by comparing the maximum peak value of the corresponding search box with the noise and the Pth peak value, it is confirmed whether the maximum peak value of each search box is valid. If the maximum peak values ​​of at least two search boxes are valid, the position verification module is used to further verify the position; otherwise, the synchronization is considered to have failed. The maximum peak power is confirmed to be valid when the following formula is satisfied: Power_MAX>Power_noise*Threshold_Peak_Noise; Power_MAX>Power_Pth* Threshold_Peak_Pth; Wherein, Power_MAX represents the maximum peak power, Power_noise represents the noise power, Power_Pth represents the Pth peak power in descending order, Threshold_Peak_Noise represents the threshold ratio between the maximum peak power and the noise power, and Threshold_Peak_Pth represents the threshold ratio between the maximum peak power and the Pth peak power in descending order. Position verification module: Used to perform position verification when the peak comparison module obtains at least two valid maximum peaks. If the positional relationship of at least two valid maximum peaks meets the conditions, the synchronization is considered successful; otherwise, the synchronization is considered to have failed. The location verification module specifically includes: The position results of at least two valid maximum peaks obtained by the peak comparison module are sent to the position verification module. The difference between the maximum peak positions is obtained by subtracting the maximum peak positions pairwise and taking the modulus of 255. Count the number of values ​​in diff_poss that are less than or equal to 1. If the value is greater than or equal to 1, the synchronization is considered successful; otherwise, the synchronization is considered to have failed.

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