Composite frame synchronization method and device for spacecraft data transmission

Abstract

The application discloses a kind of composite frame synchronization method and device for spacecraft data transmission, the method comprises: obtaining AOS data frame and performing transfer frame header matching check;When transfer frame header matching fails, trigger frame error control state grading check mechanism, according to the grading situation respectively into synchronization state, soft decision state or adaptive sliding state;In soft decision state, weighted voting model is used to synthesize frame error control state, error code feature matching result and historical success rate to make decision;By similarity calculation matching historical error code mode to start targeted error correction;In adaptive sliding state, the sliding step is dynamically adjusted according to the error code condition;Efficient analysis and error code fault-tolerant processing of data frame are realized.

Description

Technical Field

[0001] This invention relates to the field of space data link communication data parsing technology, specifically to a composite frame synchronization method and apparatus for spacecraft data transmission. Background Technology

[0002] As humanity's demand for exploring outer space continues to expand, countries have launched a large number of spacecraft for Earth observation and deep space exploration, generating a large amount of observational data of different types and sizes that needs to be transmitted back to Earth for processing.

[0003] In response to the diverse types of spacecraft data and the large differences in code rates, the Consultative Committee for Space Data Systems (CCSDS) developed the Advanced Orbit System (AOS) protocol standard for air-to-air and air-to-ground data transmission and processing.

[0004] According to relevant standards such as "CCSDS 732.00-B-2-2006 AOS Data Link Protocol", "ISO 22666:2016 Space Data and Information Transmission Systems. AOS (Advanced On-Orbit Protocol) Space Data Link Protocol" and "GB / T39345-2020 Space Data and Information Transmission Systems. Advanced On-Orbit System Space Data Link Protocol", a typical CCSDS AOS frame data format includes four main parts: transmission frame lead header, transmission frame insert field, transmission frame data field, and transmission frame trailer.

[0005] During spacecraft-to-Earth data transmission, equipment malfunctions and interference from lightning, rain, snow, etc., can lead to problems such as payload data transmission failure, data errors, and frame loss. Those skilled in the art can determine whether there are at least bit-level errors in the transmitted frames by studying equipment performance, frame synchronization, decoding, and other technologies.

[0006] However, in existing AOS frame data parsing and processing, when the transmit frame master header matching verification fails, the common approach is to directly discard the data to avoid introducing erroneous data. However, this method also causes a jump in the transmit frame master header count, leading to data processing anomalies and resulting in the loss of a large amount of valid payload data, posing significant difficulties for subsequent data processing. Therefore, how to maximize the preservation and extraction of valid data from the transmit frame data field when the transmit frame master header verification fails is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] In view of the above problems, the present invention provides a composite frame synchronization method based on multi-level frame error control verification and dynamic state transition model to solve the problem of data loss in the parsing of AOS frame data in the prior art.

[0008] To achieve the above objectives, a first aspect of the present invention discloses a composite frame synchronization method for spacecraft data transmission, the method comprising:

[0009] S1. Acquire AOS data frames for spacecraft data transmission; the AOS data frame includes a frame header and frame data;

[0010] S2. According to the standard AOS data frame format, perform frame leader header matching verification on the AOS data frame to obtain the first judgment result;

[0011] When the first judgment result is a successful match, step S6 is executed;

[0012] When the first judgment result is a matching failure, step S3 is executed;

[0013] S3. Perform frame error control state hierarchical verification on the frame data to obtain frame error control verification results; when the frame error control verification result is less than the first error rate, execute step S6; when the frame error control verification result is greater than the second error rate, execute step S5; otherwise, execute step S4; the frame error control verification result represents the frame data error rate.

[0014] S4. Perform soft-decision error correction processing on the frame data to obtain an AOS data frame containing a standard frame master header, and then execute step S6.

[0015] S5. Perform backward sliding processing on the data transmitted by the spacecraft to obtain an AOS data frame containing a standard frame master header, and then execute step S6.

[0016] S6. Mark the state of the AOS data frame as synchronized.

[0017] As an optional implementation, in a first aspect of the present invention, the step of performing soft-decision state error correction processing on the frame data to obtain an AOS data frame containing a canonical frame master header includes:

[0018] S41. Perform similarity calculation on the frame leader header of the AOS data frame and the historical error feature vector library to obtain the frame leader header error similarity value; the historical error feature vector library includes no less than 1000 historical frame leader header error feature vectors.

[0019] S42. Determine whether the frame main header error similarity value is greater than a preset first similarity threshold, and obtain a second determination result;

[0020] If the second judgment result is yes, then proceed to step S43; otherwise, proceed to step S5.

[0021] S43. Using a voting formula, score the frame error control verification result, the frame main header error similarity value, and the historical success rate to obtain a score value.

[0022] The voting formula is expressed as follows:

[0023]

[0024] In the formula, V represents the score, and w i c represents the weight of the voting contribution item. i To indicate the compliance of the voting contribution item; the voting contribution item is one of the following: frame error control verification result, frame leader header error similarity value, and historical success rate;

[0025] S44. Determine whether the score value exceeds the frame error control verification threshold, and obtain a third judgment result;

[0026] If the third judgment result is yes, then proceed to step S6; otherwise, proceed to step S45.

[0027] S45. Determine whether the frame leader header error similarity value is greater than a preset second similarity value threshold, and obtain a fourth determination result;

[0028] If the fourth judgment result is yes, then proceed to step S46; otherwise, proceed to step S48.

[0029] S46. Add the frame-leading header error feature vector to the historical error feature vector library to obtain the updated historical error feature vector library.

[0030] S47. Based on the dynamic threshold adjustment model, process the updated historical error feature vector library to obtain the updated historical success rate.

[0031] S48. Perform error correction processing on the frame data, and correct the dominant header of the AOS data frame to a normalized frame dominant header to obtain an AOS data frame containing a normalized frame dominant header.

[0032] As an optional implementation, in the first aspect of the present invention, the step of performing a similarity calculation between the frame leader header of the AOS data frame and the historical error feature vector library to obtain a frame leader header error similarity value includes:

[0033] S411. Extract the frame leading header error features of the AOS data frame to obtain the frame leading header error feature vector; the dimension of the frame leading header error feature vector is the same as the dimension of the historical error feature vector.

[0034] S412. Using a similarity calculation model, the similarity between the frame leading header error feature vector and the historical error feature vector library is calculated to obtain the frame leading header error similarity value.

[0035] As an optional implementation, in the first aspect of the present invention, the step of extracting the frame leader header error features of the AOS data frame to obtain the frame leader header error feature vector includes:

[0036] S4111. Based on the dimension of the historical error feature vector, the frame leader header of the AOS data frame is divided into T segments of data to obtain a frame leader header data segment sequence; where T is equal to the dimension of the historical error feature vector.

[0037] S4112. Select any frame dominant header data segment from the frame dominant header data segment sequence, and use the bit error rate intensity construction model to process the any frame dominant header data segment to obtain the bit error rate intensity corresponding to the any frame dominant header data segment.

[0038] The error rate strength construction model is expressed as follows:

[0039]

[0040] In the formula, M y Let M(x,y) represent the bit error intensity corresponding to the dominant header data segment of the y-th frame, I represent the number of bytes included in the data segment, M(x,y) represent the bit error intensity corresponding to the x-th byte in the dominant header data segment of the y-th frame, and P represent the number of historical bit error feature vectors contained in the historical bit error feature vector library. x This indicates whether the header data segment of the y-th frame contains an error at the x-th byte position, p t This indicates whether the x-th byte position of frame t in the historical error feature vector library contains an error. If there is an error, then p... x p t The value is 1 if it is not 1, and 0 otherwise; δ represents the Dirac function, τ represents the time decay constant; Δt represents the time interval, characterizing the time difference between the current frame and the t-th frame, used to measure the temporal impact of historical bit errors on the current bit error strength, e -Δt / τ This represents the exponential decay term, which reflects the time decay effect of historical bit errors on the current bit error strength. That is, as the time interval Δt increases, the impact of historical bit errors will weaken exponentially.

[0041] S4113. Repeat step S4112 to complete the calculation of the bit error intensity corresponding to all frame-dominant header data segments in the frame-dominant header data segmentation sequence, and integrate them to obtain the frame-dominant header bit error feature vector; each dimension of the frame-dominant header bit error feature vector represents the bit error intensity of the corresponding frame-dominant header data segment.

[0042] As an optional implementation, in the first aspect of the present invention, the similarity calculation model is used to calculate the similarity between the frame leading header error feature vector and the historical error feature vector library to obtain the frame leading header error similarity value.

[0043] S4121. Using the heatmap feature vector generation model, the historical error feature vector library is processed to obtain the historical feature library vector;

[0044] The heatmap feature vector generation model is as follows:

[0045]

[0046] In the formula, M(i,1) represents the bit error intensity element of the historical bit error feature vector, T represents the dimension of the historical bit error feature vector, and P represents the number of historical bit error feature vectors contained in the historical bit error feature vector library.

[0047] S4122. Using a similarity calculation model, process the frame leading header error feature vector and the historical feature library vector to obtain the frame leading header error similarity value.

[0048] The similarity calculation model is as follows:

[0049]

[0050] In the formula, S represents the frame leading header bit error similarity value. This represents the dominant header error feature vector of the current frame. Represents the vector of the historical feature library. Let Euclidean norm be the vector.

[0051] As an optional implementation, in the first aspect of the present invention, the dynamic threshold adjustment model is represented as:

[0052]

[0053] Among them, T zcckz (t) represents the updated historical success rate, T base This represents the historical success rate before the update, with an adaptive coefficient α = 0.3, e i Let e ​​be the historical bit error rate of the i-th historical bit error feature vector. max =10 -2 The baseline error limit is defined as N; N represents the number of historical error feature vectors contained in the historical error feature vector library.

[0054] As an optional implementation, in the first aspect of the present invention, the step of performing backward sliding processing on the data transmitted by the spacecraft to obtain an AOS data frame containing a canonical frame master header includes:

[0055] S51. The data transmitted by the spacecraft is processed by sliding backward with a first sliding step to obtain the next AOS data frame; the first sliding step is no more than 2 bytes.

[0056] S52. Determine whether the frame leader header of the next AOS data frame is a standard frame leader header, and obtain the fifth determination result;

[0057] If the fifth judgment result is yes, then an AOS data frame containing a standard frame master header is obtained; otherwise, step S53 is executed.

[0058] S53. The data transmitted by the spacecraft is processed by sliding backward with a second sliding step size until an AOS data frame containing a standard frame master header is obtained; the second sliding step size is not less than 2 bytes and not greater than the standard frame master header data length.

[0059] A second aspect of this invention discloses a composite frame synchronization device for spacecraft data transmission, used to implement a composite frame synchronization method for spacecraft data transmission disclosed in the first aspect of this invention. The device includes:

[0060] The AOS data frame acquisition module is used to acquire AOS data frames for spacecraft data transmission; the AOS data frame includes a frame leader header and frame data.

[0061] The frame leader header matching and verification module is used to perform frame leader header matching and verification on the AOS data frame according to the standard AOS data frame format.

[0062] The frame error control state classification and verification module is used to perform frame error control state classification and verification on the frame data to obtain the frame error control verification result.

[0063] The AOS data frame error correction processing module is used to perform soft-decision state error correction processing on the frame data to obtain an AOS data frame containing a standard frame master header.

[0064] The AOS data frame sliding processing module is used to slide the data transmitted by the spacecraft backward to obtain AOS data frames containing the standard frame master header.

[0065] The AOS data frame synchronization state marking module is used to mark the state of the AOS data frame as synchronized and send it to subsequent processes for processing.

[0066] A third aspect of this invention discloses yet another composite frame synchronization device for spacecraft data transmission, the device comprising:

[0067] Memory containing executable program code;

[0068] A processor coupled to the memory;

[0069] The processor calls the executable program code stored in the memory to execute the composite frame synchronization method for spacecraft data transmission disclosed in the first aspect of the present invention.

[0070] The fourth aspect of the present invention discloses a computer-readable storage medium storing computer instructions, which, when invoked, are used to execute the composite frame synchronization method for spacecraft data transmission disclosed in the first aspect of the present invention.

[0071] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0072] This application provides a composite frame synchronization method and apparatus for spacecraft data transmission. The method performs frame synchronization based on multi-level frame error control verification and dynamic state transition. When frame leader header matching fails, the hierarchical verification mechanism provided in this application is triggered. According to the consistent frame error control status identified by the decoding result, the method enters the synchronization state, soft decision state, or adaptive sliding dynamic state respectively. The frame error control verification threshold is optimized in real time through a dynamic threshold adjustment model, and the criterion sensitivity is adjusted by combining historical bit error rate and benchmark bit error upper limit. A bit error feature heat map model is constructed and feature vectors are generated. Historical bit error patterns are matched through similarity calculation to initiate targeted error correction. In the soft decision state, a weighted voting model is used to make a decision by comprehensively considering the frame error control status, bit error feature matching results, and historical success rate. The sliding step size is dynamically adjusted according to the number of sliding steps. In a weak interference environment, single-byte precise positioning is used, while in a strong interference environment, the mode of coarse positioning of the entire transmission frame leader header byte length is switched. Finally, the transmission frame leader header matching, frame error control verification, and decision-making operations are executed in parallel through a composite verification pipeline to achieve efficient parsing of data frames and bit error tolerance processing.

[0073] Compared to existing technologies that discard frames directly after failing the AOS frame header matching check, the computation scheme provided in this invention can achieve efficient parallel processing through hardware pipelines or multithreading, effectively improving data utilization and latency stability, and significantly reducing average processing latency and bit error rate. It is suitable for the data link layer data transmission and data parsing service requirements of spacecraft air-to-ground and air-to-air communication using advanced on-orbit system space data link protocols. Attached Figure Description

[0074] Figure 1This is a schematic flowchart of a composite frame synchronization method for spacecraft data transmission disclosed in an embodiment of the present invention;

[0075] Figure 2 This is a schematic diagram of a composite frame synchronization device for spacecraft data transmission disclosed in an embodiment of the present invention;

[0076] Figure 3 This is a schematic diagram of another composite frame synchronization device for spacecraft data transmission disclosed in an embodiment of the present invention. Detailed Implementation

[0077] 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.

[0078] According to standards such as CCSDS, in a typical AOS protocol, each data type is identified by a virtual channel, and the valid data is filled in it. A typical AOS frame data format includes four main parts: the transmission frame main header, the transmission frame insertion field, the transmission frame data field, and the transmission frame tail.

[0079] The main header of a transmission frame includes at least four parts: the main channel identifier, the virtual channel identifier, the virtual channel frame count, and the signaling field.

[0080] The main channel identifier includes the transmission frame version number and the spacecraft identifier, which is a fixed code for the same spacecraft; the virtual channel identifier is used to identify different service data categories within the same spacecraft; the virtual channel frame count provides a separate count for each virtual channel, which is a sequential binary counter that cannot be reset before reaching its maximum value except in unavoidable circumstances; the signaling field is used to store the playback identifier, the virtual channel frame count recycling identifier, etc.

[0081] The transmit frame insertion field is optional and follows immediately after the transmit frame header without any gap. It is used to fill in various types of service data.

[0082] The transmit frame data field contains an MPDU, a BPDU, a VCASDU, or idle data, used to carry valid data for spacecraft air-to-ground and air-to-air communications.

[0083] The transmit frame trailer includes a frame operation control field and a frame error control field, which are optional. The frame error control field is typically used to detect errors introduced into the transmit frame during transmission and data processing.

[0084] Example 1

[0085] Please see Figure 1 . Figure 1 This is a schematic diagram of the composite frame synchronization method for spacecraft data transmission disclosed in an embodiment of the present invention.

[0086] like Figure 1 As shown, the composite frame synchronization method for spacecraft data transmission disclosed in this embodiment of the invention is applicable to data link layer data transmission systems for spacecraft air-to-ground and air-to-air communication in environments with strong interference; the method includes:

[0087] S1. Acquire AOS data frames for spacecraft data transmission; the AOS data frame includes a frame header and frame data;

[0088] S2. According to the standard AOS data frame format, perform frame leader header matching verification on the AOS data frame to obtain the first judgment result;

[0089] When the first judgment result is a successful match, step S6 is executed;

[0090] When the first judgment result is a matching failure, step S3 is executed;

[0091] S3. Perform frame error control state hierarchical verification on the frame data to obtain frame error control verification results; when the frame error control verification result is less than the first error rate, proceed to step S6; when the frame error control verification result is greater than the second error rate, proceed to step S5; otherwise, proceed to step S4; the frame error control verification result represents the frame data error rate; it should be noted that RS, LDPC, etc. can be used to perform frame error control state hierarchical verification on the frame data; optionally, the first error rate is 0.1%, or 2 bits; the second error rate is 10%;

[0092] S4. Perform soft-decision error correction processing on the frame data to obtain an AOS data frame containing a standard frame master header, and then execute step S6.

[0093] S5. Perform backward sliding processing on the data transmitted by the spacecraft to obtain an AOS data frame containing a standard frame master header, and then execute step S6.

[0094] S6. Mark the state of the AOS data frame as synchronized. After the state of the AOS data frame is marked as synchronized, it is sent to the subsequent process for processing.

[0095] As can be seen, by using the method described in this embodiment, data frames with mismatched frame headers are respectively entered into the synchronization state, soft decision state, or adaptive sliding dynamic processing by classifying the frame error control state results. For controllable error situations, the frame is directly marked as the synchronization state or after error correction, which solves the problem of directly discarding and wasting communication resources in the prior art.

[0096] In another optional embodiment, the soft-decision state error correction processing of the frame data to obtain an AOS data frame containing a canonical frame master header includes:

[0097] S41. Perform similarity calculation on the frame leader header of the AOS data frame and the historical error feature vector library to obtain the frame leader header error similarity value; the historical error feature vector library includes no less than 1000 historical frame leader header error feature vectors.

[0098] S42. Determine whether the frame main header bit error similarity value is greater than a preset first similarity threshold, and obtain a second determination result; Optionally, the first similarity threshold is 0.85;

[0099] If the second judgment result is yes, then proceed to step S43; otherwise, proceed to step S5.

[0100] S43. Using a voting formula, score the frame error control verification result, the frame main header error similarity value, and the historical success rate to obtain a score value.

[0101] The voting formula is expressed as follows:

[0102]

[0103] In the formula, V represents the score, and w i c represents the weight of the voting contribution item. i To indicate the compliance of the voting contribution item, a value of 1 is taken when it is compliant and a value of 0 is taken when it is not compliant; the voting contribution item is one of the following: frame error control verification result, frame main header error similarity value, and historical success rate; it should be noted that in this embodiment, three voting contribution items are set (for example, whether the frame error control decoding result error rate is less than 5%, whether the feature matching similarity is greater than 0.85, and whether the historical success rate is greater than 80%).

[0104] S44. Determine whether the score value exceeds the frame error control verification threshold to obtain a third determination result; optionally, the frame error control verification threshold is set to 1.

[0105] If the third judgment result is yes, then proceed to step S6; otherwise, proceed to step S45.

[0106] S45. Determine whether the frame main header error similarity value is greater than a preset second similarity value threshold to obtain a fourth determination result; Optionally, the second similarity value threshold is 0.92;

[0107] If the fourth judgment result is yes, then proceed to step S46; otherwise, proceed to step S48.

[0108] S46. Add the frame-leading header error feature vector to the historical error feature vector library to obtain the updated historical error feature vector library.

[0109] S47. Based on the dynamic threshold adjustment model, process the updated historical error feature vector library to obtain the updated historical success rate.

[0110] S48. Perform error correction processing on the frame data, and correct the dominant header of the AOS data frame to a normalized frame dominant header to obtain an AOS data frame containing a normalized frame dominant header.

[0111] In another optional embodiment, the step of performing a similarity calculation between the frame leader header of the AOS data frame and the historical error feature vector library to obtain a frame leader header error similarity value includes:

[0112] S411. Extract the frame leading header error features of the AOS data frame to obtain the frame leading header error feature vector; the dimension of the frame leading header error feature vector is the same as the dimension of the historical error feature vector.

[0113] S412. Using a similarity calculation model, the similarity between the frame leading header error feature vector and the historical error feature vector library is calculated to obtain the frame leading header error similarity value.

[0114] In another optional embodiment, the extraction of frame leader header error features from the AOS data frame to obtain a frame leader header error feature vector includes:

[0115] S4111. Based on the dimension of the historical error feature vector, the frame leader header of the AOS data frame is divided into T segments of data to obtain a frame leader header data segment sequence; where T is equal to the dimension of the historical error feature vector.

[0116] S4112. Select any frame dominant header data segment from the frame dominant header data segment sequence, and use the bit error rate intensity construction model to process the any frame dominant header data segment to obtain the bit error rate intensity corresponding to the any frame dominant header data segment.

[0117] The error rate strength construction model is expressed as follows:

[0118]

[0119] In the formula, M y Let M(x,y) represent the bit error intensity corresponding to the dominant header data segment of the y-th frame, I represent the number of bytes included in the data segment, M(x,y) represent the bit error intensity corresponding to the x-th byte in the dominant header data segment of the y-th frame, and P represent the number of historical bit error feature vectors contained in the historical bit error feature vector library. xThis indicates whether the header data segment of the y-th frame contains an error at the x-th byte position, p t This indicates whether the x-th byte position of frame t in the historical error feature vector library contains an error. If there is an error, then p... x p t The value is 1 if it is not 1, and 0 otherwise; δ represents the Dirac function, τ represents the time decay constant; Δt represents the time interval, which characterizes the time difference between the current frame and the t-th frame, and is used to measure the time impact of historical errors on the current error strength; e -Δt / τ This represents the exponential decay term, which reflects the time decay effect of historical errors on the current error intensity. That is, as the time interval Δt increases, the impact of historical errors will weaken exponentially.

[0120] S4113. Repeat step S4112 to complete the calculation of the bit error intensity corresponding to all frame-dominant header data segments in the frame-dominant header data segmentation sequence, and integrate them to obtain the frame-dominant header bit error feature vector; each dimension of the frame-dominant header bit error feature vector represents the bit error intensity of the corresponding frame-dominant header data segment.

[0121] In another optional embodiment, the extraction of frame leader header error features from the AOS data frame to obtain a frame leader header error feature vector includes:

[0122] S4114. Based on the dimension of the historical error feature vector, the frame leader header of the AOS data frame is divided into T segments of data to obtain a frame leader header data segment sequence; where T is equal to the dimension of the historical error feature vector.

[0123] S4115. Extract any data segment from the frame-leading header data segment sequence;

[0124] S4116. Calculate the bit error location distribution entropy, the mean length of consecutive bit errors, and the bit error rate of any data segment;

[0125] The method for calculating the error location distribution entropy is as follows:

[0126]

[0127] In the formula, H represents the error location distribution entropy, which characterizes the uniformity of error distribution at the frame leader header position; I represents the number of bytes included in the data segment, p i This represents the probability of an error occurring in the i-th byte.

[0128] The method for calculating the average length of consecutive bit errors is as follows:

[0129]

[0130] In the formula, The mean consecutive bit error length represents the average length of consecutive bit errors; m represents the number of consecutive bit errors; L represents the number of consecutive bit errors. j Indicates the length of the j-th consecutive bit error segment;

[0131] The method for calculating the bit error rate of data segmentation is as follows:

[0132]

[0133] In the formula, P e N represents the data segment error rate, which characterizes the overall error rate of a data segment; e N represents the number of bits with errors in the data segment. t The total number of bits for data segments;

[0134] S4117. The bit error intensity of any data segment is obtained by summing the bit error location distribution entropy, the mean length of consecutive bit errors, and the bit error rate of data segments.

[0135] S4118. Repeat steps S4115 to S4117 to complete the calculation of the bit error intensity of all data segments and obtain the frame leader header bit error feature vector.

[0136] The above scheme, by extracting error features from multiple dimensions, can comprehensively reflect the error situation of the frame-leading header, thus improving the accuracy and reliability of error features.

[0137] In another optional embodiment, the similarity calculation model is used to calculate the similarity between the frame leading header error feature vector and the historical error feature vector library to obtain the frame leading header error similarity value.

[0138] S4121. Using the heatmap feature vector generation model, the historical error feature vector library is processed to obtain the historical feature library vector;

[0139] The heatmap feature vector generation model is as follows:

[0140]

[0141] In the formula, M(i,1) represents the error intensity element of the historical error feature vector, N represents the dimension of the historical error feature vector, and P represents the number of historical error feature vectors contained in the historical error feature vector library.

[0142] It should be noted that the method for calculating the historical error feature vectors in the historical error feature vector library is the same as the method used in step S411.

[0143] Based on the heatmap feature vector generation model, the values ​​of each row of the historical bit error feature vector are added together, and the 8×N matrix is ​​compressed into a 1×N feature vector. This vector reflects the total bit error intensity of each time frame, transforming the spatiotemporal bit error distribution into a 1×N dimensional feature vector. By compressing the original 8×N matrix into a 1×N vector, the storage space is reduced by 87.5%.

[0144] S4122. Using a similarity calculation model, process the frame leading header error feature vector and the historical feature library vector to obtain the frame leading header error similarity value.

[0145] The similarity calculation model is as follows:

[0146]

[0147] In the formula, S represents the frame leading header bit error similarity value. This represents the dominant header error feature vector of the current frame. Represents the vector of the historical feature library. Let Euclidean norm be the vector.

[0148] It should be noted that the historical error patterns are matched by similarity calculation to initiate targeted error correction; in the soft decision state, a weighted voting model is used to make decisions by combining the frame error control state, the similarity value of error features, and the historical success rate.

[0149] In yet another optional embodiment, the dynamic threshold adjustment model is represented as:

[0150]

[0151] Among them, T zcckz (t) represents the updated historical success rate, T base This represents the historical success rate before the update, with an adaptive coefficient α = 0.3, e i Let e ​​be the historical bit error rate of the i-th historical bit error feature vector. max =10 -2 The baseline error limit is defined as N; N represents the number of historical error feature vectors contained in the historical error feature vector library.

[0152] It should be noted that the frame error control verification threshold is optimized in real time through a dynamic threshold adjustment model, and the criterion sensitivity is adjusted by combining historical bit error rate and benchmark bit error upper limit.

[0153] In another optional embodiment, the backward sliding process of the data transmitted by the spacecraft to obtain an AOS data frame containing a canonical frame master header includes:

[0154] S51. The data transmitted by the spacecraft is processed by sliding backward with a first sliding step to obtain the next AOS data frame; the first sliding step is no more than 2 bytes.

[0155] S52. Determine whether the frame leader header of the next AOS data frame is a standard frame leader header, and obtain the fifth determination result;

[0156] If the fifth judgment result is yes, then an AOS data frame containing a standard frame master header is obtained; otherwise, step S53 is executed.

[0157] S53. The data transmitted by the spacecraft is processed by sliding backward with a second sliding step size until an AOS data frame containing a standard frame master header is obtained; the second sliding step size is not less than 2 bytes and not greater than the standard frame master header data length.

[0158] It should be noted that in the above scheme, the sliding step size is dynamically adjusted according to different historical data processing states. In the weak interference environment, single-byte precise positioning is used, while in the strong interference environment, the mode of coarse positioning of the main header byte length of the entire transmission frame is switched. By searching the frame header for adaptive sliding, the error-level data area can be quickly passed to improve the timeliness of data parsing and processing.

[0159] This method improves system throughput. Efficient parallel processing is achieved through hardware pipelines or multithreading. The processing time calculation formula includes: T_head, the frame header matching time (typically 0.12ms, affected by factors such as frame header length and hardware parallelism); T_ZCCKZ, the frame error control check flag reading time (typically 0.03ms, achieved by directly reading the frame error control status bits preset by the ground station, without recalculation); T_decision, the state transition decision time (typically 0.01ms, selected based on T_head and T_ZCCKZ results, choosing the subsequent processing path (synchronous state / soft decision state / sliding dynamic); L_frame, the data frame length (including frame header length), typically 1024 bytes, varying depending on the specific business system, determining the amount of data processed in a fixed step size; and N_parallel, the number of parallel processing channels, implemented through hardware pipelines or multithreading for parallel verification. Finally, the frame header matching (T_head) and frame error control verification (T_ZCCKZ) are performed in parallel, and the one with the longer time is selected and the decision time (T_decision) is added.

[0160] In this embodiment, time optimization is compared between traditional serial processing and the parallel processing strategy of this method. Compared to traditional serial processing: T_total = T_head + T_ZCCKZ + T_decision (cumulative time consumption), the parallel processing method of this method: T_total = max(T_head, T_ZCCKZ) + T_decision (taking the maximum value). If L_frame = 1067 bytes, T_total = 0.15ms, N_parallel = 4, the throughput is about 26MB / s. Synchronization can increase the number of parallel channels N_parallel while balancing hardware costs such as resource utilization, thereby improving throughput under the condition of balanced hardware resources.

[0161] Example 2

[0162] Please see Figure 2 . Figure 2 This is a schematic diagram of a composite frame synchronization device for spacecraft data transmission disclosed in an embodiment of the present invention.

[0163] like Figure 2 As shown in the figure, an embodiment of the present invention discloses a composite frame synchronization device for spacecraft data transmission, the device comprising:

[0164] AOS data frame acquisition module 201 is used to acquire AOS data frames for spacecraft data transmission; the AOS data frame includes a frame header and frame data.

[0165] The frame leader header matching and verification module 202 is used to perform frame leader header matching and verification on the AOS data frame according to the standard AOS data frame format.

[0166] The frame error control state classification verification module 203 is used to perform frame error control state classification verification on the frame data and obtain the frame error control verification result.

[0167] AOS data frame error correction processing module 204 is used to perform soft-decision state error correction processing on the frame data to obtain an AOS data frame containing a standard frame master header.

[0168] The AOS data frame sliding processing module 205 is used to perform backward sliding processing on the data transmitted by the spacecraft to obtain an AOS data frame containing a standard frame master header.

[0169] The AOS data frame synchronization state marking module 206 is used to mark the state of the AOS data frame as synchronized and send it to the subsequent process for processing.

[0170] This second embodiment is the product embodiment corresponding to the first embodiment. The steps and methods included are the same as those in the first embodiment, and will not be described in detail in the second embodiment.

[0171] Example 3

[0172] Please see Figure 3 , Figure 3 This is a schematic diagram of the structure of another composite frame synchronization device for spacecraft data transmission disclosed in an embodiment of the present invention. Wherein, Figure 3 The described apparatus can be applied in management systems, such as local servers or cloud servers for management, and the embodiments of the present invention are not limited thereto. Figure 3 As shown, the device may include:

[0173] Memory 301 storing executable program code;

[0174] Processor 302 coupled to memory 301;

[0175] The processor 302 calls the executable program code stored in the memory 301 to execute the steps in the composite frame synchronization method for spacecraft data transmission described in Embodiment 1.

[0176] Example 4

[0177] This invention discloses a computer-readable storage medium storing a computer program for electronic data exchange, wherein the computer program causes a computer to execute the steps in the composite frame synchronization method for spacecraft data transmission described in Embodiment 1.

[0178] The device embodiments described above are merely illustrative. The modules described as separate components may or may not be physically separate, and the components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0179] Through the detailed description of the above embodiments, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, including read-only memory (ROM), random access memory (RAM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), one-time programmable read-only memory (OTPROM), electrically-Erasable Programmable Read-Only Memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, disk storage, magnetic tape storage, or any other computer-readable medium that can be used to carry or store data.

[0180] Finally, it should be noted that the composite frame synchronization method and apparatus for spacecraft data transmission disclosed in the embodiments of the present invention are merely preferred embodiments of the present invention and are only used to illustrate the technical solutions of the present invention, not to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite frame synchronization method for spacecraft data transmission, characterized in that, The method includes: S1. Acquire AOS data frames for spacecraft data transmission; the AOS data frame includes a frame header and frame data; S2. According to the standard AOS data frame format, perform frame leader header matching verification on the AOS data frame to obtain the first judgment result; When the first judgment result is a successful match, step S6 is executed; When the first judgment result is a matching failure, step S3 is executed; S3. Perform frame error control state hierarchical verification on the frame data to obtain frame error control verification results; when the frame error control verification result is less than the first error rate, execute step S6; when the frame error control verification result is greater than the second error rate, execute step S5; otherwise, execute step S4; the frame error control verification result represents the frame data error rate. S4. Perform soft-decision error correction processing on the frame data to obtain an AOS data frame containing a standard frame master header, and then execute step S6. S5. Perform backward sliding processing on the data transmitted by the spacecraft to obtain an AOS data frame containing a standard frame master header, and then execute step S6. S6. Mark the state of the AOS data frame as synchronized.

2. The composite frame synchronization method for spacecraft data transmission according to claim 1, characterized in that, The soft-decision error correction process performed on the frame data to obtain an AOS data frame containing a canonical frame master header includes: S41. Perform similarity calculation on the frame leader header of the AOS data frame and the historical error feature vector library to obtain the frame leader header error similarity value; S42. Determine whether the frame main header error similarity value is greater than a preset first similarity threshold, and obtain a second determination result; If the second judgment result is yes, then proceed to step S43; otherwise, proceed to step S5. S43. Score the frame error control verification result, the frame main header error similarity value, and the historical success rate to obtain a score value; S44. Determine whether the score value exceeds the frame error control verification threshold, and obtain a third judgment result; If the third judgment result is yes, then proceed to step S6; otherwise, proceed to step S45. S45. Determine whether the frame leader header error similarity value is greater than a preset second similarity value threshold, and obtain a fourth determination result; If the fourth judgment result is yes, then proceed to step S46; otherwise, proceed to step S48. S46. Add the frame-leading header error feature vector to the historical error feature vector library to obtain the updated historical error feature vector library. S47. Based on the dynamic threshold adjustment model, process the updated historical error feature vector library to obtain the updated historical success rate. S48. Perform error correction processing on the frame data, and correct the dominant header of the AOS data frame to a normalized frame dominant header to obtain an AOS data frame containing a normalized frame dominant header.

3. The composite frame synchronization method for spacecraft data transmission according to claim 2, characterized in that, The step of performing similarity calculations between the frame leader header of the AOS data frame and the historical error feature vector library to obtain the frame leader header error similarity value includes: S411. Extract the frame leading header error features of the AOS data frame to obtain the frame leading header error feature vector; the dimension of the frame leading header error feature vector is the same as the dimension of the historical error feature vector. S412. Using a similarity calculation model, the similarity between the frame leading header error feature vector and the historical error feature vector library is calculated to obtain the frame leading header error similarity value.

4. The composite frame synchronization method for spacecraft data transmission according to claim 3, characterized in that, The step of extracting the frame dominant header error features of the AOS data frame to obtain the frame dominant header error feature vector includes: S4111. Based on the dimension of the historical error feature vector, the frame leader header of the AOS data frame is divided into T segments of data to obtain a frame leader header data segment sequence; where T is equal to the dimension of the historical error feature vector. S4112. Select any frame dominant header data segment from the frame dominant header data segment sequence, and use the bit error rate intensity construction model to process the any frame dominant header data segment to obtain the bit error rate intensity corresponding to the any frame dominant header data segment. The error rate strength construction model is expressed as follows: In the formula, M y Let M(x,y) represent the bit error intensity corresponding to the dominant header data segment of the y-th frame, I represent the number of bytes included in the data segment, M(x,y) represent the bit error intensity corresponding to the x-th byte in the dominant header data segment of the y-th frame, and P represent the number of historical bit error feature vectors contained in the historical bit error feature vector library. x This indicates whether the header data segment of the y-th frame contains an error at the x-th byte position, p t This indicates whether the x-th byte position of frame t in the historical error feature vector library contains an error. If there is an error, then p... x p t The value is 1 if it is not 0 otherwise; δ represents the Dirac function, τ represents the time decay constant; Δt represents the time interval, which characterizes the time difference between the current frame and the t-th frame and is used to measure the time impact of historical bit errors on the current bit error strength. S4113. Repeat step S4112 to complete the calculation of the bit error intensity corresponding to all frame-dominant header data segments in the frame-dominant header data segmentation sequence, and integrate them to obtain the frame-dominant header bit error feature vector; each dimension of the frame-dominant header bit error feature vector represents the bit error intensity of the corresponding frame-dominant header data segment.

5. The composite frame synchronization method for spacecraft data transmission according to claim 4, characterized in that, The similarity calculation model is used to calculate the similarity between the frame leading header error feature vector and the historical error feature vector library to obtain the frame leading header error similarity value. S4121. Using the heatmap feature vector generation model, the historical error feature vector library is processed to obtain the historical feature library vector; The heatmap feature vector generation model is as follows: In the formula, M(i,1) represents the error intensity element of the historical error feature vector, T represents the dimension of the historical error feature vector, and P represents the number of historical error feature vectors contained in the historical error feature vector library. S4122. Using a similarity calculation model, process the frame leading header error feature vector and the historical feature library vector to obtain the frame leading header error similarity value. The similarity calculation model is as follows: In the formula, S represents the frame leading header bit error similarity value. This represents the dominant header error feature vector of the current frame. Represents the vector of the historical feature library. Let Euclidean norm be the vector.

6. The composite frame synchronization method for spacecraft data transmission according to claim 2, characterized in that, The dynamic threshold adjustment model is expressed as follows: Among them, T zcckz (t) represents the updated historical success rate, T base This represents the historical success rate before the update, with an adaptive coefficient α = 0.3, e i Let e ​​be the historical bit error rate of the i-th historical bit error feature vector. max =10 -2 The baseline error limit is defined as N; N represents the number of historical error feature vectors contained in the historical error feature vector library.

7. The composite frame synchronization method for spacecraft data transmission according to claim 2, characterized in that, The process of sliding the data transmitted by the spacecraft backward to obtain an AOS data frame containing a canonical frame master header includes: S51. The data transmitted by the spacecraft is processed by sliding backward with the first sliding step to obtain the next AOS data frame. S52. Determine whether the frame leader header of the next AOS data frame is a standard frame leader header, and obtain the fifth determination result; If the fifth judgment result is yes, then an AOS data frame containing a standard frame master header is obtained; otherwise, step S53 is executed. S53. The data transmitted by the spacecraft is processed by sliding backward with a second sliding step size until an AOS data frame containing a canonical frame master header is obtained.

8. A composite frame synchronization device for spacecraft data transmission, characterized in that, For implementing the composite frame synchronization method for spacecraft data transmission as described in any one of claims 1-7, the apparatus comprises: The AOS data frame acquisition module is used to acquire AOS data frames for spacecraft data transmission; the AOS data frame includes a frame leader header and frame data. The frame leader header matching and verification module is used to perform frame leader header matching and verification on the AOS data frame according to the standard AOS data frame format. The frame error control state classification and verification module is used to perform frame error control state classification and verification on the frame data to obtain the frame error control verification result. The AOS data frame error correction processing module is used to perform soft-decision state error correction processing on the frame data to obtain an AOS data frame containing a standard frame master header. The AOS data frame sliding processing module is used to slide the data transmitted by the spacecraft backward to obtain AOS data frames containing the standard frame master header. The AOS data frame synchronization state marking module is used to mark the state of the AOS data frame as synchronized and send it to subsequent processes for processing.

9. A composite frame synchronization device for spacecraft data transmission, characterized in that, The device includes: Memory containing executable program code; A processor coupled to the memory; The processor calls the executable program code stored in the memory to execute the composite frame synchronization method for spacecraft data transmission as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions, which, when invoked, are used to execute the composite frame synchronization method for spacecraft data transmission as described in any one of claims 1-7.

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