CN-121441468-B - Composite frame synchronization method and device for spacecraft data transmission

CN121441468BCN 121441468 BCN121441468 BCN 121441468BCN-121441468-B

Abstract

The invention discloses a composite frame synchronization method and device for spacecraft data transmission, wherein the method comprises the steps of obtaining an AOS data frame and executing transmission frame master header matching verification, triggering a frame error control state grading verification mechanism when the transmission frame master header matching fails, respectively entering a synchronous state, a soft decision state or a self-adaptive sliding state according to grading conditions, adopting a weighted voting model to synthesize the frame error control state, an error code feature matching result and a historical success rate in the soft decision state to make a decision, calculating a matching historical error code mode through similarity to start targeted error correction, dynamically adjusting a sliding step length according to error code conditions in the self-adaptive sliding state, and realizing high-efficiency analysis of the data frame and error code fault tolerance processing.

Inventors

CHEN XUEHUA
SUN HE
WANG JUN
YANG YUCHEN
WANG GANG
ZHENG MEI
LU QI

Assignees

北京市遥感信息研究所

Dates

Publication Date: 20260508
Application Date: 20250915

Claims (10)

1. A method for synchronizing composite frames of spacecraft data transmission, said method comprising: s1, acquiring an AOS data frame of spacecraft data transmission, wherein the AOS data frame comprises a frame main header and frame data; S2, performing frame master header matching verification judgment on the AOS data frame according to a standard AOS data frame format to obtain a first judgment result; when the first judging result is that the matching is successful, executing a step S6; when the first judging result is that the matching fails, executing a step S3; S3, carrying out frame error control state grading check on the frame data to obtain a frame error control check result, executing a step S6 when the frame error control check result is smaller than a first error rate, executing a step S5 when the frame error control check result is larger than a second error rate, otherwise, executing a step S4, wherein the frame error control check result represents the frame data error rate; s4, performing soft-decision state error correction processing on the frame data to obtain an AOS data frame containing a standard frame main header, and executing a step S6; S5, performing backward sliding treatment on data transmitted by the spacecraft to obtain an AOS data frame containing a standard frame main header, and executing a step S6; s6, marking the state of the AOS data frame as the same gait.
2. The method for synchronizing composite frames for spacecraft data transmission according to claim 1, wherein said performing soft-decision state error correction on said frame data to obtain an AOS data frame having a canonical frame header comprises: s41, performing similarity calculation on a frame main header of the AOS data frame and a historical error code feature vector library to obtain a frame main header error code similarity value; S42, judging whether the frame main header error code similarity value is larger than a preset first similarity threshold value or not, and obtaining a second judging result; if the second judgment result is yes, executing a step S43, otherwise, executing a step S5; S43, scoring the frame error control check result, the frame primary header error code similarity value and the historical success rate to obtain a scoring value; S44, judging whether the grading value exceeds a frame error control check threshold value, and obtaining a third judging result; if the third judgment result is yes, executing a step S6, otherwise, executing a step S45; S45, judging whether the frame main header error code similarity value is larger than a preset second similarity value threshold value or not, and obtaining a fourth judgment result; if the fourth judgment result is yes, executing a step S46, otherwise, executing a step S48; S46, adding the frame master header error code feature vector to a historical error code feature vector library to obtain an updated historical error code feature vector library; S47, processing the updated historical error code feature vector library according to a dynamic threshold adjustment model to obtain an updated historical success rate; s48, performing error correction processing on the frame data, and correcting the main header of the AOS data frame into a standard frame main header to obtain the AOS data frame containing the standard frame main header.
3. The method for synchronizing composite frames for data transmission of a spacecraft of claim 2, wherein said performing a similarity calculation on a frame master header of said AOS data frame and a historical error feature vector library to obtain a frame master header error similarity value comprises: S411, extracting the frame main header error code characteristic of the AOS data frame to obtain a frame main header error code characteristic vector, wherein the dimension of the frame main header error code characteristic vector is the same as the dimension of the history error code characteristic vector; s412, calculating the similarity of the frame master error code feature vector and the historical error code feature vector library by using a similarity calculation model to obtain a frame master error code similarity value.
4. The method for synchronizing composite frames for spacecraft data transmission according to claim 3, wherein said extracting frame dominant head error characteristics of said AOS data frames to obtain frame dominant head error characteristic vectors comprises: s4111, dividing the frame master header of the AOS data frame into T sections of data according to the dimension of the historical error code feature vector to obtain a frame master header data segmentation sequence, wherein T is equal to the dimension of the historical error code feature vector; s4112, selecting any frame of main header data segment from the frame of main header data segment sequence, and processing the any frame of main header data segment by using an error strength construction model to obtain the error strength corresponding to the any frame of main header data segment; the error strength construction model is expressed as: Wherein M y represents the error code intensity corresponding to the data segment of the y-th frame master, I represents the byte number included in the data segment, M (x, y) represents the error code intensity corresponding to the x-th byte in the data segment of the y-th frame master, P represents the number of the historical error code feature vectors contained in the historical error code feature vector library, P x represents whether the data segment of the y-th frame master is an error code at the x-th byte position, P t represents whether the t-th frame in the historical error code feature vector library is an error code at the x-th byte position, if the error code exists, the value of P x 、p t is 1, otherwise the value is 0, delta represents a Dirac function, tau represents a time attenuation constant, delta t represents a time interval, represents the time difference between the current frame and the t-th frame, and the time influence of the historical error code on the current error code intensity is measured; S4113, circularly executing step S4112, completing the calculation of the error intensity corresponding to all the frame main header data segments in the frame main header data segment sequence, and integrating to obtain a frame main header error code feature vector, wherein each dimension of the frame main header error code feature vector represents the error intensity of the corresponding frame main header data segment.
5. The method for synchronizing composite frames for spacecraft data transmission according to claim 4, wherein said similarity calculation is performed on said frame master error feature vector and said historical error feature vector library using a similarity calculation model to obtain a frame master error similarity value; s4121, processing the historical error code feature vector library by utilizing a thermodynamic diagram feature vector generation model to obtain a historical feature library vector; the thermodynamic diagram feature vector generation model is as follows: in the formula, Representing a historical feature library vector, M (i, 1) representing error intensity elements of the historical error feature vector, T representing the dimension of the historical error feature vector, and P representing the number of the historical error feature vectors contained in the historical error feature vector library; S4122, processing the frame main header error code feature vector and the historical feature library vector by using a similarity calculation model to obtain a frame main header error code similarity value; the similarity calculation model is as follows: where S represents the frame dominant head error similarity value, Representing the current frame header error feature vector, The vectors of the historical feature library are represented, Representing the euclidean norm of the vector.
6. The method of composite frame synchronization for spacecraft data transfer of claim 2, wherein said dynamic thresholding model is expressed as: Wherein, T zcckz (T) represents the updated history success rate, T base represents the history success rate before updating, the adaptive coefficient α=0.3, e i is the history error rate of the i-th history error feature vector, e max ＝10 -2 is the upper limit of the reference error, and N represents the number of history error feature vectors contained in the history error feature vector library.
7. The method for synchronizing composite frames of data transmission of a spacecraft of claim 2, wherein said performing a backward sliding process on the data transmitted by the spacecraft to obtain an AOS data frame having a canonical frame header comprises: s51, carrying out backward sliding processing on data transmitted by a spacecraft by a first sliding step length to obtain a next AOS data frame; S52, judging whether the frame master header of the next AOS data frame is a standard frame master header or not, and obtaining a fifth judging result; If the fifth judgment result is yes, an AOS data frame containing a standard frame main header is obtained, otherwise, a step S53 is executed; And S53, performing backward sliding treatment on the data transmitted by the spacecraft by a second sliding step length until an AOS data frame containing the standard frame main header is obtained.
8. A composite frame synchronization device for spacecraft data transmission, characterized in that it is adapted to implement a composite frame synchronization method for spacecraft data transmission according to any of claims 1-7, said device comprising: The AOS data frame acquisition module is used for acquiring an AOS data frame of spacecraft data transmission, wherein the AOS data frame comprises a frame main header and frame data; the frame master header matching and checking module is used for carrying out frame master header matching and checking on the AOS data frame according to a standard AOS data frame format; The frame error control state grading verification module is used for carrying out frame error control state grading verification on the frame data to obtain a frame error control verification result; The AOS data frame error correction processing module is used for carrying out soft decision state error correction processing on the frame data to obtain an AOS data frame containing a standard frame main header; The AOS data frame sliding processing module is used for performing backward sliding processing on data transmitted by the spacecraft to obtain an AOS data frame containing a standard frame main header; And the AOS data frame synchronous state marking module is used for marking the state of the AOS data frame as synchronous state and sending the AOS data frame to a subsequent flow process for processing.
9. A composite frame synchronization device for spacecraft data transmission, the device comprising: A memory storing executable program code; A processor coupled to the memory; the processor invokes the executable program code stored in the memory to perform the composite frame synchronization method of spacecraft data transfer of any of claims 1-7.
10. A computer readable storage medium storing computer instructions which, when invoked, are adapted to perform the composite frame synchronisation method of a spacecraft data transmission of any of claims 1-7.

Description

Composite frame synchronization method and device for spacecraft data transmission Technical Field The invention relates to the technical field of space data link communication data analysis, in particular to a composite frame synchronization method and device for spacecraft data transmission. Background With the continuous expansion of the demand of human exploration space, a large number of spacecrafts are launched by each country for earth observation and deep space exploration, and a large number of different kinds of observation data with different sizes are generated and need to be transmitted back to the ground for processing. Aiming at the characteristics of multiple data types, large code rate difference and the like of the spacecraft, the space data system consultation committee (Consultative Committee for SPACE DATA SYSTEMS, CCSDS) formulates an advanced on-orbit system (Advanced Orbit System, AOS) protocol standard for air-air and air-ground data transmission and processing. AOS (advanced on-orbit protocol) space data link protocol, GB/T39345-2020 space data and information transmission system advanced on-orbit system space data link protocol, and the like, a typical CCSDS AOS frame data format comprises a transmission frame main header, a transmission frame insertion field, a transmission frame data field and a transmission frame tail 4 for the most part. In the process of transmitting ground data of a spacecraft, due to equipment failure, lightning, rain and snow and other interferences, the problems of load data transmission failure, data error code, frame loss and the like can be caused. Those skilled in the art can determine whether at least a bit-level error condition exists in the transmitted frame by studying techniques such as device performance, frame synchronization, decoding, etc. However, in the existing process of analyzing and processing the data of the AOS frame, when the matching and checking of the main header of the transmission frame fails, a direct discarding processing method is generally adopted to avoid introducing error data, but the method also causes the jump of the count of the main header of the transmission frame, thereby causing abnormal data processing, causing loss of a large amount of payload effective data and bringing great difficulty to subsequent data processing. Therefore, how to maximally preserve and extract valid data in the transmission frame data field when the transmission frame header check fails is a technical problem that needs to be solved by those skilled in the art. Disclosure of Invention In view of the above problems, the present invention provides a composite frame synchronization method based on a multi-level frame error control check and dynamic state transition model, so as to solve the problem of data loss in the prior art AOS frame data analysis. To achieve the above objective, a first aspect of the present invention discloses a composite frame synchronization method for spacecraft data transmission, where the method includes: s1, acquiring an AOS data frame of spacecraft data transmission, wherein the AOS data frame comprises a frame main header and frame data; S2, performing frame master header matching verification judgment on the AOS data frame according to a standard AOS data frame format to obtain a first judgment result; when the first judging result is that the matching is successful, executing a step S6; when the first judging result is that the matching fails, executing a step S3; S3, carrying out frame error control state grading check on the frame data to obtain a frame error control check result, executing a step S6 when the frame error control check result is smaller than a first error rate, executing a step S5 when the frame error control check result is larger than a second error rate, otherwise, executing a step S4, wherein the frame error control check result represents the frame data error rate; s4, performing soft-decision state error correction processing on the frame data to obtain an AOS data frame containing a standard frame main header, and executing a step S6; S5, performing backward sliding treatment on data transmitted by the spacecraft to obtain an AOS data frame containing a standard frame main header, and executing a step S6; s6, marking the state of the AOS data frame as the same gait. In a first aspect of the embodiment of the present invention, the performing soft-decision state error correction processing on the frame data to obtain an AOS data frame including a standard frame header includes: S41, performing similarity calculation on a frame main header of the AOS data frame and a historical error code feature vector library to obtain a frame main header error code similarity value, wherein the historical error code feature vector library comprises not less than 1000 historical frame main header error code feature vectors; S42, judging whether the frame main header error code similarity value is larger