Anti-frequency offset data link synchronization method under hypersonic speed and related equipment

Abstract

The invention provides an anti-frequency offset data link synchronization method under hypersonic speed and related equipment, and relates to the technical field of data processing. The method comprises the following steps: firstly, acquiring a data chain transmission signal S (n), and performing similarity operation on the data chain transmission signal S (n) and a local pilot signal A (n) with known characteristics to obtain a related signal P (n); next, by setting a delay factor m, carrying out delay processing on the correlation signal to obtain P (n-m), and carrying out double correlation operation on the original correlation signal P (n) and a delay processing result P (n-m) to obtain a double correlation numerical value Y (n-m); and when the double correlation numerical value exceeds a preset threshold value, a synchronization point of the data chain can be determined, the synchronization point indicates that the receiving end and the sending end reach consistent key positions in the aspects of time, frequency or phase, and finally data chain synchronization is completed based on the synchronization point. A synchronization point can be accurately found for information synchronization in a frequency offset environment generated by hypersonic speed.

Description

Technical Field

[0001] This application relates to the technical field of data processing, and in particular, to a method for synchronizing a data link with anti-frequency offset under hypersonic speed and related devices. Background Art

[0002] In the field of modern communication technologies, with the continuous growth and diversification of data transmission requirements, data link synchronization technology becomes increasingly crucial in numerous complex environments. Whether it is long-distance data interaction in military communications or real-time data transmission in industrial automation control, strict requirements are imposed on the accuracy and efficiency of data link synchronization.

[0003] Traditional data link synchronization technologies often insert specific pilot signals into the data signals at the sending end, and the receiving end then uses the known characteristics (such as frequency, phase, etc.) of the pilot signals to determine the synchronization point for synchronization.

[0004] However, traditional data link synchronization methods may have a large frequency offset under some hypersonic speeds, making it difficult for the receiving end to correctly find the synchronization point when performing operations such as correlation detection on the pilot signals, thus prolonging the synchronization establishment time or resulting in synchronization failure. Summary of the Invention

[0005] This application provides a method for synchronizing a data link with anti-frequency offset under hypersonic speed and related devices, which is used to solve the problem that it is difficult to find the correct synchronization point due to severe frequency offset under hypersonic and high-speed motion states, and improves the synchronization performance of the data link in an environment with high frequency offset.

[0006] In a first aspect, this application provides a method for synchronizing a data link with anti-frequency offset under hypersonic speed, which is applied to a server. The method includes: obtaining a signal S(n) transmitted by the data link in the current environment; performing a similarity operation on the signal S(n) and a local pilot signal A(n) to obtain a correlation signal P(n), where the pilot signal A(n) is a pilot signal with known characteristics locally in advance; after setting a delay factor m, performing a delay process on the correlation signal P(n) according to the delay factor m to obtain a delay process result P(n - m); performing a two-fold correlation operation on the correlation signal P(n) and the delay process result P(n - m) again to obtain a two-fold correlation value Y(n - m); determining whether the two-fold correlation value Y(n - m) exceeds a preset threshold; if the two-fold correlation value Y(n - m) exceeds the preset threshold, determining the synchronization point of the current data link, where the synchronization point refers to a key position or moment at which the receiving end and the sending end are at least consistent in terms of time, frequency, or phase; and synchronizing the data link according to the synchronization point.

[0007] By adopting the above technical solutions, the preliminary relevant operations aim to extract the part that may be similar to the pilot signal from the received complex data link transmission signal S(n). By setting the delay factor and performing delay processing, the displacement characteristics of the signal can be obtained in the time domain, which is equivalent to providing a comparison reference. It can observe the correlation of the signal before and after a certain time delay, helping to comprehensively grasp the characteristics of the signal and the synchronization law hidden therein, and preparing for more accurately finding the synchronization point. Performing the relevant operations again will further increase the relevant value corresponding to the synchronization signal and make the characteristics more prominent. It is like a secondary screening, making the characteristics of the synchronization signal clearer and facilitating accurate identification. Through the two-fold relevant operations and comparison with the preset threshold, the synchronization point of the current data link can be determined more precisely, and then it can be more accurately determined that the synchronization point at the receiving end and the sending end are consistent in terms of time, frequency, or phase, etc., and then the data link is synchronized, ensuring the accuracy of data link synchronization in a complex and frequency-offset-interference-prone environment such as hypersonic speed.

[0008] Combined with some embodiments of the first aspect, in some embodiments, after the step of determining whether the two-fold correlation value Y(n - m) exceeds the preset threshold, it further includes: if the two-fold correlation value Y(n - m) does not exceed the preset threshold, continue to receive the signal S(n) and perform the similarity operation until the termination condition is met. The termination condition includes that the two-fold correlation value Y(n - m) exceeds the preset threshold or the preset search times are completed.

[0009] By adopting the above technical solutions, this cyclic iterative processing mechanism ensures to a certain extent that the server can continuously search for the optimal synchronization point in a complex environment. By setting the limit of the preset search times, it avoids the server falling into an infinite loop and guarantees the reasonable utilization of server resources.

[0010] Combined with some embodiments of the first aspect, in some embodiments, before the step of determining whether the two-fold correlation value Y(n - m) exceeds the preset threshold, it further includes: obtaining a historical data set in a known frequency offset environment. The historical data set includes two-fold correlation values with marks indicating whether the data link is successfully synchronized; constructing a threshold judgment model based on multiple marked historical data sets. The threshold judgment model is used to determine the size of the preset threshold after two-fold correlation processing of the signal according to the current communication environment; after obtaining the current communication environment data, determine the current preset threshold in combination with the threshold judgment model.

[0011] By adopting the above technical solution, a threshold judgment model is constructed based on the historical data set. This model contains the successful synchronization experience in the known frequency offset environment. The threshold judgment model can dynamically adjust the size of the preset threshold according to the characteristics of the current communication environment. This adaptive threshold determination mechanism enables the server to flexibly adjust the judgment criteria according to the changes in the actual communication environment, greatly improving the accuracy of synchronization judgment.

[0012] Combined with some embodiments of the first aspect, in some embodiments, before the step of delaying the correlation signal P(n) according to the delay factor m to obtain the delayed processing result P(n - m), it further includes: determining the delay factor m according to a preset condition, where the preset condition includes that the delay factor m satisfies m < mmax, and the value of mmax is fs / 2 / fx, where fs is the signal sampling frequency and fx is the set frequency parameter related to the frequency offset.

[0013] By adopting the above technical solution, the setting of the delay factor m is limited within a reasonable range, that is, less than half of the ratio of the sampling frequency to the frequency offset related parameter. This scientific constraint ensures that the delay processing is carried out within an effective range, avoiding signal distortion caused by excessive delay.

[0014] Combined with some embodiments of the first aspect, in some embodiments, the step of performing a two - fold correlation operation on the correlation signal P(n) and the delayed processing result P(n - m) again to obtain the two - fold correlation value Y(n - m) specifically includes: determining the two - fold correlation value Y(n - m) according to the formula Y(n - m)=P(n)*conj(P(n - m)), where conj represents the conjugate operation.

[0015] By adopting the above technical solution, this precise mathematical processing method can effectively extract the phase information of the signal. Through the conjugate operation, the imaginary component in the signal can be eliminated, obtaining a more stable correlation result. This processing method not only improves the accuracy of synchronization point detection but also enhances the server's adaptability to frequency offset.

[0016] Combined with some embodiments of the first aspect, in some embodiments, after the step of synchronizing the data link according to the synchronization point, it further includes: when a new synchronization point is obtained, pausing the current data link synchronization, retaining the signal data within a set time as historical data reference; adjusting the synchronization of the data link to the position of the new synchronization point and resuming the data link synchronization operation.

[0017] By adopting the above technical solution, the signal data will be temporarily retained for a certain time as a reference after obtaining a new synchronization point. This mechanism not only ensures the continuity of synchronization but also provides a buffer for possible synchronization adjustment.

[0018] In combination with some embodiments of the first aspect, in some embodiments, after the step of synchronizing the data link according to the synchronization point, the method further includes: determining a target time position according to the synchronization point, and selecting signal data within a set time window before and after the synchronization point as a data segment to be processed; performing denoising processing on the data segment to be processed.

[0019] By adopting the above technical solution, this selective processing method based on a time window not only ensures the pertinence of processing but also reduces the consumption of computing resources.

[0020] In a second aspect, the present application provides a server, which includes: one or more processors and a memory; the memory is coupled to the one or more processors, and the memory is used to store computer program code, the computer program code includes computer instructions, and the one or more processors call the computer instructions to enable the server to execute the method described in the first aspect and any possible implementation manner in the first aspect.

[0021] In a third aspect, the present application provides a computer-readable storage medium, including instructions, when the instructions run on the server, enabling the server to execute the method described in the first aspect and any possible implementation manner in the first aspect.

[0022] In a fourth aspect, the present application provides a computer program product, when the computer program product runs on the server, enabling the server to execute the method described in the first aspect and any possible implementation manner in the first aspect.

[0023] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: 1. By adopting the above technical solution, since the technical means of performing similarity calculation between the signal and the local pilot signal and then performing two-fold correlation processing based on the delay factor is adopted, effectively solves the technical problem in the prior art that it is difficult to accurately find the synchronization point due to the frequency offset interference in the hypersonic environment during data link synchronization. Furthermore, it realizes anti-frequency offset and accurately finds the synchronization point in a high-frequency offset environment for stable and reliable data link synchronization, significantly improving the data synchronization accuracy.

[0024] 2. By adopting the above technical solution, since the technical means of constructing a threshold judgment model based on the historical data set and dynamically adjusting the preset threshold is adopted, effectively solves the technical problem in the prior art that a fixed threshold is difficult to adapt to a complex and changeable communication environment. Furthermore, it realizes the adaptive adjustment of the threshold judgment standard, enabling the server to accurately identify the synchronization point according to the actual communication environment characteristics, and greatly improving the adaptability of the server under different communication conditions.

[0025] 3. By adopting the above technical solution, since a two-fold correlation numerical calculation method based on signal conjugate operation is used, the technical problem of unstable correlation operation results in the prior art is effectively solved. Furthermore, the accurate extraction of signal phase information is realized, and the frequency offset tolerance range and synchronization reliability of the server are significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic flowchart of a method for anti-frequency-offset data link synchronization at hypersonic speed in an embodiment of the present application; Figure 2 is another schematic flowchart of a method for anti-frequency-offset data link synchronization at hypersonic speed in an embodiment of the present application; Figure 3 is a schematic structural diagram of an entity device of a server in an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The terms used in the following embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. As used in the specification and claims of the present application, the singular forms "a", "an", "the", "above", "said", "this" are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used in the present application refers to and includes any or all possible combinations of one or more of the listed items.

[0028] Hereinafter, the terms "first" and "second" are only used for descriptive purposes, and cannot be construed as implying or indicating relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present application, unless otherwise specified, the meaning of "a plurality" is two or more.

[0029] For ease of understanding, the method provided in this embodiment is described in terms of a process below. Please refer to Figure 1 , which is a schematic flowchart of a method for anti-frequency-offset data link synchronization at hypersonic speed in an embodiment of the present application.

[0030] S101. Obtain a signal S(n) transmitted by the data link in the current environment; The server first needs to obtain the data link transmission signal S(n) in the current environment. Here, the server refers to the hardware platform or device that implements the anti-frequency-offset data link synchronization method under hypersonic speed, or other infrastructure of some communication servers. The base station or relay node can also be used as the server. The specific implementation of this step is that the server pre-configures a signal receiving module, which includes a signal receiving unit, a signal amplification and filtering unit, an analog-to-digital conversion unit, etc. When starting the synchronization process, the signal receiving unit listens for radio signals within a specific frequency range. When a transmission signal is detected, it amplifies and filters the signal to remove noise and interference signals. Then, the analog-to-digital conversion unit samples and quantizes the filtered analog signal, converts it into a digital signal format, and stores it in the signal buffer of the server. Considering the Doppler shift of the signal frequency in a high-speed mobile scenario, the signal receiving module can use a broadband antenna and a tunable RF front-end to adapt to a wide range of frequency offsets. Finally, the server extracts the digital signal S(n) from the signal buffer as the input signal for subsequent processing. The signal S(n) contains the original modulation signal to be transmitted by the data link in the current environment.

[0031] S102. Perform a similarity operation on the signal S(n) and the local pilot signal A(n) to obtain a correlation signal P(n). The pilot signal A(n) is a pilot signal with known characteristics locally. After obtaining the transmission signal S(n), the server needs to preprocess it using the local pilot signal A(n). The specific implementation is that the server can generate multiple local pilot signals. The parameters of these pilot signals, such as frequency, code pattern, transmission time, etc., are preset. The server will send the specified pilot signal A(n) according to the control instruction issued during synchronization. This pilot signal serves as a known reference signal during the synchronization process, and its waveform and characteristics are stored in the local pilot signal library of the server in advance. Next, the server takes the received transmission signal S(n) and the local pilot signal A(n) as inputs, and uses a specific correlation algorithm to perform the correlation operation of the two signals. Then, the correlation signal P(n) of the operation result is obtained. This correlation signal reflects the similarity between the input signal S(n) and the local pilot signal A(n), that is, the degree of matching between the two in the time domain, frequency domain, and code domain.

[0032] S103. After setting the delay factor m, perform a delay process on the correlation signal P(n) according to the delay factor m to obtain a delay process result P(n - m). After obtaining the correlation signal P(n), the server needs to set a delay factor m for delaying the correlation signal P(n). The specific implementation method is that the server determines a reasonable value of the delay factor m according to a preset parameter equation or a machine learning model. The parameter equation is m < mmax, where mmax = (fs / 2) / fx, fs is the sampling frequency of the signal S(n), and fx is the frequency value corresponding to the estimated maximum frequency offset range. The determination of this parameter equation is based on the sampling theorem to ensure that the delay factor m does not exceed the maximum phase shift range that can be represented by the sampling frequency.

[0033] The server will also obtain the correlation signal P(n) and the value of the delay factor m, and then perform a time-domain delay process on the correlation signal P(n) according to the P(n - m) related formula, where n represents the signal time index. Finally, the delayed signal P(n - m) is output. The specific signal delay processing method is as follows: cache the correlation signal P(n), and the signal obtained by reading m samples offset from the buffer is the delay processing result. Mathematically speaking, for each sampling moment n in the signal sequence, to obtain its delayed corresponding value, it is to find the sampling value with index n - m in the original signal sequence. For example, if we imagine the signal P(n) as a column of troops arranged in order, each soldier is like a sampling value, and n is the number on the soldier. Now, to perform a delay process with a delay factor m of 3, then the original soldier numbered 5 (i.e., n = 5), after the delay process, corresponds to the position and value of the soldier numbered 2 (i.e., n - m = 5 - 3 = 2) in the original troop. That is to say, in the time domain, the entire signal P(n) is like being translated backward by m time units as a whole.

[0034] By performing a delay operation on the correlation signal P(n), the displacement characteristics of the signal can be obtained in the time domain, providing a basis for subsequent double correlation operations. Appropriately setting the delay factor m can improve the discrimination of the double correlation result, enhance the useful signal, and suppress noise interference.

[0035] S104. Perform a double correlation operation on the correlation signal P(n) and the delayed processing result P(n - m) again to obtain a double correlation value Y(n - m); After obtaining the delayed signal P(n - m), the server performs a two-fold correlation operation on the relevant signal P(n) and the delayed signal P(n - m). The specific implementation method is that the server obtains the original correlation signal P(n) and the delayed correlation signal P(n - m) as input signals, and then calculates the two-fold correlation result of the two signals in the form of dot product according to the mathematical formula of the two-fold correlation operation, that is, Y(n - m) = P(n) * conj[P(n - m)]. Among them, conj[] represents taking the conjugate complex value of the input signal. The two-fold correlation value Y(n - m) reflects the correlation degree between the correlation signal P(n) and its delayed version P(n - m). The reason for using the two-fold correlation operation is that for the displacement correlation signal caused by frequency offset, the single-fold correlation operation often has difficulty accurately estimating the synchronization position or other key parameters of the signal, because the frequency offset will cause the signal to change in both the time domain and the frequency domain. In the time domain, the signal may have an obvious displacement, just like the originally neatly arranged signal sequence is stretched or compressed. This displacement will interfere with the conventional single-fold correlation operation based on a fixed window or a fixed template. For example, in a communication server, due to factors such as the relative movement between the transmitter and the receiver or the instability of the local oscillator, the received signal may have a frequency offset. If only the single-fold correlation operation is used to process, when the frequency offset causes the signal to be displaced, the correlation peak may appear at the wrong position, resulting in an incorrect judgment of the starting position or the synchronization position of the signal. The two-fold correlation operation helps to adapt to different degrees of frequency offset. In different application scenarios or communication environments, the degree of frequency offset may vary greatly. For a small frequency offset, the single-fold correlation operation may still be able to barely cope. For a large frequency offset, the two-fold correlation operation can process the frequency offset problem in stages. The first-fold correlation operation can perform a preliminary correction or estimation on a large range of frequency offsets, and the second-fold correlation operation can more accurately locate the signal position or extract signal parameters for the signal after the preliminary processing, so that the entire server can have better performance under different degrees of frequency offset. In addition, through the conjugate operation, the imaginary part of the signal can be eliminated, which helps to extract the main features of the signal. Therefore, the two-fold correlation result Y(n - m) can more accurately reflect the correlation of the synchronization signal.

[0036] S105. Determine whether the two-fold correlation value Y(n - m) exceeds a preset threshold; After obtaining the result Y(n - m) of the two-fold correlation operation, the server needs to determine whether the correlation value exceeds the preset threshold to determine whether the correct synchronization point has been obtained. The specific implementation method is that the server dynamically sets a reasonable decision threshold according to the current communication environment conditions for the decision analysis of the two-fold correlation value Y(n - m).

[0037] The server will, based on the current relevant value Y(n - m) and the current threshold level, then use a simple numerical comparison to determine the magnitude relationship between Y(n - m) and the threshold. If Y(n - m) exceeds the current threshold, it is determined that the two signals have a very strong correlation and a correct synchronization point is considered to be obtained. If Y(n - m) does not exceed the threshold, it indicates insufficient correlation and further search is required. This judgment method based on dynamic threshold setting can adaptively adjust the judgment conditions according to the parameter status of the specific communication environment, avoiding synchronization errors caused by too low or too high threshold settings. At the same time, using historical data for model training can continuously optimize the threshold setting strategy and improve the synchronization success rate.

[0038] In some embodiments, when it is determined that the double correlation value Y(n - m) obtained in two stages does not exceed the preset threshold, it indicates that the current correlation value is not sufficient to determine the synchronization point. At this time, the server will not terminate the processing but will continue to return to the steps of signal reception and similarity calculation, that is, receive the next signal S(n) and re - perform the correlation operation with the local pilot signal A(n) to obtain a new correlation signal P(n). In this way, through the loop iteration method, the double correlation value can be continuously searched and judged until a certain termination condition is met: the first termination condition is that the double correlation value Y(n - m) exceeds the preset threshold, and at this time, the synchronization point is directly determined; the second termination condition is that the preset maximum search times have been completed, that is, after a specified number of loops, the synchronization point has not been found. At this time, the server will automatically exit the current search process. This loop processing mechanism ensures that the server can continuously adjust and find the optimal synchronization point in a complex environment, avoiding judgment errors caused by terminating with a single judgment. At the same time, setting the maximum search times can also prevent the server from falling into an overly deep invalid search loop, ensuring the rationality of the processing flow and the resource utilization efficiency.

[0039] S106. If the double correlation value Y(n - m) exceeds the preset threshold, determine the synchronization point of the current data link. The synchronization point refers to a key position or moment when the receiving end and the sending end are at least consistent in terms of time, frequency, or phase. If, in step S105, the threshold judgment unit determines that the current double correlation value Y(n - m) exceeds the preset dynamic threshold, it is considered that the correct synchronization point has likely been found. The server will confirm the current synchronization status and complete the storage of relevant parameters. Specifically, when the server determines that synchronization is successful, it will update the current synchronization status flag to "synchronized" and record the synchronization time. It will also determine the peak position of the current correlation value Y(n - m) based on its time-domain waveform characteristics, that is, the moment when the maximum correlation occurs. Based on this moment, important parameters such as the symbol time deviation, subcarrier frequency deviation, etc. between the transmitter and receiver signals can be calculated in reverse. These parameters reflect the precise alignment relationship between the transmitter and receiver in the time domain, frequency domain, and code domain, etc.

[0040] After the above synchronization parameters are calculated, the server will adjust the local code time base, frequency reference, and phase reference to align them completely with the transmitter, so as to achieve time-domain synchronization, frequency-domain synchronization, and code-domain synchronization of the signal. At this time, the server officially enters the locked state, establishing a stable end-to-end signal transmission link and achieving accurate and reliable data link synchronization.

[0041] S107. Synchronize the data link based on this synchronization point.

[0042] After successfully obtaining the synchronization point and calculating the relevant alignment parameters, the server needs to complete the end-to-end data link synchronization process based on this information. Specifically, the server obtains the relevant alignment parameters output from the previous step and reconfigures the local data link module to complete the synchronization process. The data link module includes a data link sending component and a data link receiving component. After adjusting the local time base frequency according to the relevant alignment parameters, the data link sending component will readjust the symbol timing of the transmitter signal according to the calculated symbol time deviation to achieve precise time alignment from the transmitter to the receiver.

[0043] In some embodiments, when the server detects a new synchronization point during the current data link synchronization process, it can first pause the current data link synchronization operation. After pausing the synchronization, the server will continue to retain and store the received signal data within a preset time window as historical data reference. This part of the retained historical signal data can provide a reference for subsequent synchronization adjustment, avoiding problems such as data link overlap or discontinuity after adjustment. After retaining the historical signal data, the server will adjust the current data link synchronization point to the position of the newly detected better synchronization point. After adjusting the synchronization point, the server resumes the data link synchronization process and continues the subsequent synchronization operation according to the new synchronization point. If the new synchronization point has a large adjustment, the historical data can be used as a compensation reference to adjust parameters such as the phase and timestamp of the data link to ensure the precise connection of the data link before and after the adjustment. Through the above processing, it is possible to ensure the precise coherence of the data link timing while continuously optimizing the synchronization point, avoiding problems such as judgment errors or data inconsistencies caused by synchronization adjustment.

[0044] In some embodiments, according to the finally determined synchronization point, the target time position of the entire data link transmission can be deduced, that is, the precise corresponding point of the data links at the sending end and the receiving end on the time axis. After determining the target time position, the server will select a time window within a set range before and after the synchronization point, such as the signal data within 1 millisecond before and after the synchronization point time. The signal data segment collected within this time window will be used as the data segment to be processed for subsequent specific processing. Among them, the server will perform denoising processing on the data segment to be processed, and specifically, technical means such as signal filtering and noise reduction can be used. After processing, it can effectively remove signal contaminations such as random noise and narrowband interference in the data segment and extract cleaner effective signals. This can improve the accuracy of subsequent information parsing, parameter extraction, etc. based on this data segment. Since only the data within a specific time window around the synchronization point is selected for processing, the processing range can be reduced and the computational complexity can be lowered.

[0045] In the above embodiments, by using the anti-frequency offset data link synchronization method in the embodiments of the present application, through performing similarity operation on the acquired signal and the local pilot signal and then performing two-fold correlation processing based on the delay factor, the synchronization point can be accurately found in a high-frequency offset environment, and thus stable and reliable data link synchronization can be achieved. It not only effectively solves the technical problem in the prior art that it is difficult to accurately determine the synchronization point due to the frequency offset interference in the hypersonic environment, but also significantly improves the anti-frequency offset ability and synchronization accuracy of the server.

[0046] After combining the above content, the following further describes the more specific process of the method provided in this embodiment. Please refer to Figure 2 , which is another process schematic diagram of the anti-frequency offset data link synchronization method in the embodiments of the present application.

[0047] S201. Obtain a historical data set in a known frequency offset environment, where the historical data set includes a two-fold correlation value with a mark indicating whether the data link is successfully synchronized; Before determining whether the two-fold correlation value Y(n - m) exceeds a preset threshold, the server can obtain a historical data set in a known frequency offset environment, which contains the two-fold correlation operation results and corresponding synchronization success marks under different frequency offset conditions. The specific implementation method is that the server first collects the past synchronization historical data and also obtains the key data indicators during the data link synchronization in different communication environments. One of the main indicators is the result Y(n - m) of the two-fold correlation operation. Each time the data link is synchronized in a specific environment, the historical data acquisition module will extract a set of data sets containing frequency offset parameters, the two-fold correlation value Y(n - m), and a mark indicating whether the synchronization is finally successful, and temporarily store them in the server. Considering that the frequency offset parameters in different communication environments may vary greatly, the historical data set memory will conduct a large number of offline simulation tests to test the data link synchronization performance of the two-fold correlation method under various preset frequency offset settings, and record the key indicator data. In addition, for the historical records during the data link synchronization obtained in actual applications, after being labeled, they can also be fed back to the server to continuously enrich the quantity of the historical data set and make it contain more actual scenario information. Finally, before each synchronization decision, the server will query and extract a set of historical data sets with the most similar characteristics in the current communication environment, including the two-fold correlation value and the success mark, and use this as data support for constructing a threshold judgment model.

[0048] S202. Construct a threshold judgment model based on multiple historical data sets with marks, where the threshold judgment model is used to determine the size of the preset threshold after the two-fold correlation processing of the signal according to the current communication environment; After obtaining the historical data set containing the two-fold correlation value and the synchronization success mark, the server needs to use this historical data to construct a threshold judgment model for dynamically determining the synchronization decision threshold in the current communication environment.

[0049] Specifically, the server obtains a historical data set of the markers that have not been successfully synchronized, and then uses machine learning algorithms to train this data to obtain a threshold judgment model. Considering the need to quickly respond to changes in the current communication environment, a linear regression algorithm can be used here to build the model. During the model training process, this module uses the frequency offset parameters in the historical data as independent variables, the two-fold correlation values as dependent variables, and the synchronization success marker as a label. Through multiple iterations, it approaches a decision boundary to maximize the proportion of correctly judging synchronization success or failure. After training is completed, the model can be expressed as Y = k1×f1 + k2×f2 +... + b, where f1 and f2 represent the parameters of the frequency offset environment, k1 and k2 are weight coefficients, and b is a bias term. This parameterized model is saved for future use.

[0050] Before starting a new synchronization process, this module will obtain the frequency offset parameter data in the current communication environment and substitute it into the model for calculation to obtain a threshold for the current applicable two-fold correlation result. That is to say, this model can output a dynamically changing threshold size based on the real-time input environmental parameters. Finally, this adaptive threshold is input into the threshold judgment unit for subsequent synchronization point judgment.

[0051] S203. After obtaining the current communication environment data, determine the current preset threshold in combination with this threshold judgment model.

[0052] After building the adaptive threshold judgment model, the server can determine a suitable threshold for the two-fold correlation result according to the current communication environment parameters each time. The specific implementation method is that whenever a new data link synchronization process starts, the server will detect the current communication environment, obtain the parameters that may affect the frequency offset, including information such as moving speed, movement direction, signal frequency, etc., and format them into an input parameter vector recognizable by the model. Then, this parameter vector is input into the threshold judgment model saved in the threshold model construction module for calculation. The model will output a threshold for the current suitable two-fold correlation result based on these parameters and temporarily store this output threshold. After obtaining the two-fold correlation operation result Y(n - m) subsequently, the server can compare this dynamically set current threshold with Y(n - m) to determine whether the correlation result exceeds the threshold to determine the final synchronization success or failure.

[0053] In the embodiments of this application, this machine learning-driven adaptive threshold setting method enables the threshold judgment criterion to be dynamically adjusted during the synchronization judgment of the server, accurately adapt to the specific conditions of the current channel and frequency offset, improve the accuracy of synchronization detection, and enhance the adaptability of the server in complex and changing environments.

[0054] The server in the embodiments of this invention application will be described from the perspective of hardware processing. Please refer to Figure 3, which is a schematic structural diagram of an entity device of the server in the embodiments of the present application.

[0055] It should be noted that Figure 3 The structure of the server shown is only an example and should not impose any limitations on the functions and usage scope of the embodiments of the present invention.

[0056] As Figure 3 shown, the server includes a central processing unit (CPU) 301, which can perform various appropriate actions and processes according to the program stored in the read-only memory (ROM) 302 or the program loaded from the storage section 308 into the random access memory (RAM) 303, such as executing the method described in the above embodiments. In the RAM 303, various programs and data required for system operation are also stored. The CPU 301, ROM 302, and RAM 303 are connected to each other via a bus 304. An input / output (I / O) interface 305 is also connected to the bus 304.

[0057] The following components are connected to the I / O interface 305: an input section 306 including an audio input device, a button switch, etc.; an output section 307 including a liquid crystal display (LCD), an audio output device, an indicator light, etc.; a storage section 308 including a hard disk, etc.; and a communication section 309 including a network interface card such as a LAN (Local Area Network) card, a modem, etc. The communication section 309 performs communication processing via a network such as the Internet. A drive 310 is also connected to the I / O interface 305 as needed. A removable medium 311, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 310 as needed so that a computer program read from it can be installed into the storage section 308 as needed.

[0058] Particularly, according to the embodiments of the present invention, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiments of the present invention include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains a computer program for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication section 309 and / or installed from the removable medium 311. When the computer program is executed by the central processing unit (CPU) 301, various functions defined in the present invention are executed.

[0059] It should be noted that specific examples of computer-readable storage media may include, but are not limited to: electrical connections with one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, optical fibers, portable compact disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above. In the present invention, a computer-readable storage medium can be any tangible medium that contains or stores a program, and this program can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0060] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of the present invention. Among them, each block in the flowchart or block diagram may represent a module, a program segment, or a part of code, and the above-mentioned module, program segment, or part of code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than that marked in the accompanying drawings.

[0061] Specifically, the server in this embodiment includes a processor and a memory, and a computer program is stored on the memory. When the computer program is executed by the processor, it implements the anti-frequency-offset data link synchronization method under hypersonic speed provided in the above-mentioned embodiment.

[0062] On the other hand, the present invention also provides a computer-readable storage medium, which may be included in the server described in the above-mentioned embodiment; or it may exist separately and not be assembled into the server. The above-mentioned storage medium carries one or more computer programs. When the above-mentioned one or more computer programs are executed by a processor of the server, the server is enabled to implement the anti-frequency-offset data link synchronization method under hypersonic speed provided in the above-mentioned embodiment.

[0063] As mentioned above, the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the various embodiments of the present application.

[0064] As used in the foregoing embodiments, depending on the context, the term "when" may be construed to mean "if", "after", "in response to determining", or "in response to detecting". Similarly, depending on the context, the phrase "upon determining" or "if (the stated condition or event) is detected" may be construed to mean "if determined", "in response to determining", "when (the stated condition or event) is detected", or "in response to detecting (the stated condition or event)".

[0065] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the foregoing embodiments can be implemented by a computer program instructing relevant hardware. The program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the foregoing method embodiments. The foregoing storage medium includes various media that can store program codes, such as ROM, random access memory (RAM), magnetic disks, or optical discs.

Claims

1. A method for synchronizing a data link with frequency deviation resistance at hypersonic speed, applied to a server, characterized in that: The method includes: Obtaining a signal S(n) transmitted by a data link in the current environment; Performing a similarity operation on the signal S(n) and a local pilot signal A(n) to obtain a correlation signal P(n), where the pilot signal A(n) is a pilot signal with known characteristics locally in advance; After setting a delay factor m, performing a delay process on the correlation signal P(n) according to the delay factor m to obtain a delay processing result P(n - m); Performing a two - fold correlation operation on the correlation signal P(n) and the delay processing result P(n - m) again to obtain a two - fold correlation value Y(n - m); Judging whether the two - fold correlation value Y(n - m) exceeds a preset threshold; If the two - fold correlation value Y(n - m) exceeds the preset threshold, determining a synchronization point of the current data link, where the synchronization point refers to a key position or moment when the receiving end and the sending end are at least consistent in terms of time, frequency, or phase; Synchronizing the data link according to the synchronization point.

2. The method according to claim 1, characterized in that After the step of judging whether the two - fold correlation value Y(n - m) exceeds a preset threshold, it further includes: If the two - fold correlation value Y(n - m) does not exceed the preset threshold, continue to receive the signal S(n) and perform a similarity operation until a termination condition is met, where the termination condition includes that the two - fold correlation value Y(n - m) exceeds the preset threshold or a preset number of search times is completed.

3. The method according to claim 1, characterized in that: Before the step of judging whether the two - fold correlation value Y(n - m) exceeds a preset threshold, it further includes: Obtaining a historical data set in a known frequency offset environment, where the historical data set includes two - fold correlation values with marks indicating whether the data link is successfully synchronized; Constructing a threshold judgment model according to multiple historical data sets with marks, where the threshold judgment model is used to determine the size of the preset threshold after two - fold correlation processing of a signal according to the current communication environment; After obtaining the current communication environment data, determining the current preset threshold in combination with the threshold judgment model.

4. The method according to claim 1, characterized in that: Before the step of, after setting the delay factor m, performing a delay process on the correlation signal P(n) according to the delay factor m to obtain a delay processing result P(n - m), it further includes: Determining the delay factor m according to a preset condition, where the preset condition includes that the delay factor m satisfies m < mmax, and the value of mmax is fs / 2 / fx, where fs is the signal sampling frequency and fx is a set frequency parameter related to the frequency offset.

5. The method according to claim 1, characterized in that In the step of performing a two - fold correlation operation on the correlation signal P(n) and the delay processing result P(n - m) again to obtain a two - fold correlation value Y(n - m), specifically includes: Determining the two - fold correlation value Y(n - m) according to the formula Y(n - m)=P(n)*conj(P(n - m)), where conj represents the conjugate operation.

6. The method according to claim 1, characterized in that After the step of synchronizing the data link according to the synchronization point, it further includes: When a new synchronization point is obtained, pausing the current data link synchronization and retaining the signal data within a set time as a historical data reference; Adjusting the synchronization of the data link to the new synchronization point position and resuming the data link synchronization operation.

7. The method according to claim 1, characterized in that After the step of synchronizing the data link according to the synchronization point, the method further includes: According to the target time position determined by the synchronization point, the signal data within the set time window before and after the synchronization point is selected as the data segment to be processed; The data segment to be processed is subjected to denoising processing.

8. A server, characterized in that: The server includes: one or more processors and a memory; the memory is coupled to the one or more processors, the memory is used to store computer program code, the computer program code includes computer instructions, and the one or more processors call the computer instructions to enable the server to execute the method described in any one of claims 1-7.

9. A computer-readable storage medium comprising instructions, characterized in that: When the instructions are executed on a server, the server is caused to execute the method according to any one of claims 1 to 7.

10. A computer program product, characterized in that When the computer program product is run on a server, the server is caused to execute the method according to any one of claims 1 to 7.

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