Processing method of satellite data transmission data

Abstract

The invention provides a satellite data transmission data processing method, which is used for a satellite, and comprises the following steps: obtaining a file set needing to be sent to a ground communication network, packaging the file set into N file blocks by using a preset packaging mode, each file block comprising file header information and file data information, N > = 1, the file header information is used for the receiver to acquire at least part of data of the file set by taking the file block as the minimum unit and check the correctness of the single file block; the N file blocks are packaged into one or more data packets, each data packet is configured to be capable of containing T file blocks, and T is larger than or equal to 2; sending out the one or more data packets in the form of wireless signals; according to the method, whether each file block is correct or not can be independently identified on the receiving side, the situation that the whole data packet is completely discarded under the condition that the data packet has errors but part of data is correct is avoided, and link resource waste caused by retransmission of the whole data packet is reduced.

Description

Technical Field

[0001] The present invention relates to the field of satellite technology, in particular to the field of satellite-to-earth communication technology, and more particularly to a method for processing satellite digital transmission data. Background Art

[0002] With the advancement of technology, the tasks undertaken by satellites are becoming increasingly complex, and with it comes a surge in the amount of data processing. In the field of commercial aerospace, how to optimize the use of data transmission link resources, improve the efficiency of satellite data acquisition, and resist external interference to ensure data integrity have become the key to improving satellite performance.

[0003] In onboard computing systems, data transmission plays a vital role. However, external factors such as cosmic rays and channel interference often cause data loss or corruption during transmission. Currently, existing technologies mainly rely on fault-tolerant technologies based on error correction codes to deal with these problems, but these technologies are not ideal when faced with severe data loss or corruption. Once the data corruption exceeds the verification capability, or the checksum error occurs due to byte flipping or missing, these technologies are often unable to recover valid data. When a mandatory check of a data packet fails, the entire data packet will be discarded (packet loss processing), resulting in a waste of link resources.

[0004] It should be noted that this background technology is only used to introduce the relevant information of the present invention to help understand the technical solution of the present invention, but it does not mean that the relevant information is necessarily the prior art. The relevant information is submitted and disclosed together with the present invention solution. If there is no evidence that the relevant information has been disclosed before the application date of the present invention, the relevant information shall not be regarded as the prior art. Summary of the invention

[0005] Therefore, the object of the present invention is to overcome the defects of the prior art and provide a method for processing satellite data transmission.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] According to the first aspect of the present invention, a method for processing satellite data transmission is provided, which is used for a satellite, and the method comprises: obtaining a file set to be sent to a ground communication network, packaging the file set into N file blocks using a preset packaging method, each file block including file header information and file data information, N≥1, wherein the file header information is used by the receiving party to obtain at least part of the data of the file set and verify the correctness of a single file block with the file block as the minimum unit; encapsulating the N file blocks into one or more data packets, wherein each data packet is configured to be able to load T file blocks, T≥2; and sending the one or more data packets in the form of wireless signals. The scheme can at least achieve the following beneficial technical effects: the file set to be transmitted is packaged into the form of file blocks by a preset packaging method, and one data packet can carry at least two file blocks, and the file header information of each file block is used by the receiving party to receive at least part of the data of the file set and verify the correctness of a single file block with the file block as the minimum unit, so that each file block can be independently identified on the receiving side as to whether it is correct, avoiding the entire data packet being discarded when there is an error in the data packet but part of the data is correct, and reducing the link resource waste caused by retransmitting the entire data packet.

[0008] Optionally, each file header information carries description information and verification information of the file data information in the same file block, wherein the description information includes a file name field, a file size field, and other description fields, wherein the file name field is used by the receiver to extract the file name to create a file, the file size field is used by the receiver to read data corresponding to the file size into the created file, the other description fields are used by the receiver to extract other description related information to modify the properties of the created file, and the verification information is used to verify the correctness of a single file block. This solution can at least achieve the following beneficial technical effects: through the information carried in the file header information, it can effectively achieve obtaining at least part of the data of a file set as the smallest unit and verifying the correctness of a single file block, so as to reduce the data discarded when the satellite-to-ground data transmission is disturbed and causes data packet errors.

[0009] Optionally, the preset file packaging method includes using an improved Tar packaging algorithm to package the file set, wherein the verification information in each file block in the improved Tar packaging algorithm is calculated using all contents other than the verification field of the file block. This solution can at least achieve the following beneficial technical effects: the existing Tar packaging algorithm is verification information designed to verify the entire Tar file, which is only used to verify the correctness of the entire Tar package. The method of the present invention is improved to verification information for verifying a single file block, so as to support the separate verification of each file block in the data packet, so as to identify the correctness and integrity of each file block.

[0010] Optionally, the checksum information is a checksum or hash value calculated using all contents except the checksum field of the file block.

[0011] Optionally, before sending the one or more data packets in the form of wireless signals, preset redundant data is added to the header and tail of each data packet to obtain an anti-interference packet, and each data packet is sent in the form of an anti-interference packet. This solution can at least achieve the following beneficial technical effects: The design purpose of these redundant data is to compensate for data loss caused by external interference (such as electromagnetic interference, signal attenuation, etc.) during the transmission process. At the beginning and end of the satellite-to-ground link transmission, large link jitter can easily cause data loss. Placing redundant data before and after the data packet can protect the valid data in the middle. Data loss during the jitter time is more likely to lose the redundant data before and after, reducing the probability of losing valid data.

[0012] Optionally, the method further includes: obtaining a plurality of levels of interference ranges preset and the redundant data length corresponding to each interference range, wherein a higher level of interference range represents a stronger interference and the corresponding redundant data length is relatively longer; monitoring the interference intensity of the current satellite-to-ground communication link, and dynamically adjusting the length of the redundant data in the currently sent anti-interference packet according to the interference range of the interference intensity, wherein the length of the anti-interference packet is predetermined, and when the length of the redundant data is increased, the number of stacked file blocks in the data packet is reduced. This scheme can at least achieve the following beneficial technical effects: This scheme can dynamically adjust the length of the redundant data according to the interference situation of the channel, so as to use relatively longer redundant data when the interference intensity is large, so as to reduce the probability of data packet damage when the interference intensity of the link is strong, so as to reduce data retransmission.

[0013] Optionally, the redundant data is a specified value or a stacked specified value, and the length of the redundant data is adjusted by increasing or decreasing the number of stacked specified values, which is specified by the protocol or sent by the satellite to the ground communication network before each anti-interference packet is sent. This solution can at least achieve the following beneficial technical effects: the redundant data is efficiently implemented by stacking specified values, which can reduce the difficulty of implementation and the additional occupation of communication resources. For example, when dynamically adjusting the length of redundant data, it is only necessary to adjust the number of stacked specified values. Even if the length of redundant data changes, the ground only needs to remove the specified values ​​one by one after obtaining the anti-interference packet, without repeatedly notifying the satellite of the specific value of the current redundant data, thereby reducing the occupation of communication resources by notifying the specific value of the redundant data when the interference intensity changes repeatedly.

[0014] According to the second aspect of the present invention, there is provided a data processing method, which is applied to a receiver in a ground communication network, and the method comprises: obtaining a received signal corresponding to a wireless signal sent according to the method of the first aspect; extracting each received data packet from the received signal, and obtaining at least part of the data of a file set and verifying the correctness of a single file block from each received data packet with a file block as the smallest unit, and marking correct file blocks and erroneous file blocks; for each received data packet, obtaining information about the erroneous file block, and only requesting the satellite to retransmit the erroneous file block. This scheme can at least achieve the following beneficial technical effects: According to this scheme, when an error occurs in a data packet, the entire data packet does not need to be discarded, and only the satellite needs to retransmit the erroneous file block.

[0015] Optionally, each file header information carries description information of the file data information in the same file block, and the description information includes a file name field, a file size field and other description fields. For each file in the file set, if all file blocks related to the file are marked as correct file blocks, the file is parsed in the following manner: the file name is extracted from the file name field in the file header information of the relevant file block in the received data packet to create a file; according to the file size field, data corresponding to the file size is read from the relevant file block into the created file; according to other description fields, other description related information is extracted to modify the properties of the created file to obtain the parsed file.

[0016] According to a third aspect of the present invention, a satellite-to-ground communication system is provided, comprising: a satellite for implementing the method as described in the first aspect, which is configured to: obtain a file set to be sent to a ground communication network, and package the file set into N file blocks using a preset file packaging method, each file block including file header information and file data information, N≥1, wherein the file header information is used by a receiver to obtain at least part of the data of the file set with the file block as the minimum unit and to verify the correctness of a single file block; encapsulate the N file blocks into one or more data packets, wherein each data packet is configured to be able to load T file blocks, T≥2; add preset redundant data to the header and tail of each data packet to obtain an anti-interference packet, so as to prevent the anti-interference packet from being damaged. Each of the one or more data packets is sent in the form of a satellite; a ground device for implementing the method as described in the second aspect, which is configured to: obtain a received signal corresponding to the wireless signal sent by the satellite; extract each received anti-interference packet from the received signal, and remove the specified values ​​from the header and the tail of each anti-interference packet one by one according to the specified values ​​in the redundant data obtained in advance to remove the redundant data, so as to obtain each received data packet; from each received data packet, obtain at least part of the data of the file set with the file block as the smallest unit and verify the correctness of a single file block, and mark the correct file block and the erroneous file block; for each received data packet, obtain the information of the erroneous file block, and only request the satellite to retransmit the erroneous file block.

[0017] Compared with the prior art, the advantages of the present invention are:

[0018] 1. Maximizing link resource utilization: Through the introduction of redundant data and intelligent fault-tolerant mechanisms, even when data transmission is unstable or bit errors occur, some valid information (including correct file blocks) can still be extracted, reducing the overall loss of data packets and greatly improving data transmission efficiency.

[0019] 2. Reduce retransmission frequency: The flexible parsing algorithm can directly extract some valid data without affecting data integrity, avoiding the waste of link resources caused by frequent retransmission, thereby reducing the mission burden of satellite operation in orbit.

[0020] 3. Improved anti-interference capability: By adding redundant data to the packet header and the packet tail, the invention achieves more stable data transmission in complex environments, with a low packet loss rate during transmission, ensuring the transmission of more valid data and greatly improving the reliability and robustness of the system.

[0021] In summary, the method of the present invention has significant effects in saving resources, improving transmission efficiency and enhancing performance, solves the bottleneck problem in the prior art, and has high practical value and broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The embodiments of the present invention are further described below with reference to the accompanying drawings, in which:

[0023] Figure 1 A schematic diagram of a process of processing satellite data transmission data according to an embodiment of the present invention;

[0024] Figure 2 A schematic diagram of the structure of a data packet according to an embodiment of the present invention;

[0025] Figure 3 This is a schematic diagram of the interference to the satellite data transmission process;

[0026] Figure 4 A schematic diagram of adding redundant data to form an anti-interference packet according to an embodiment of the present invention;

[0027] Figure 5 The figure is a schematic diagram of the ground unpacking process according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below through specific embodiments in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0029] As mentioned in the background technology section, when a mandatory check of a data packet fails, the entire data packet will be discarded (packet loss processing), resulting in a waste of link resources. The method of the present invention packages the file set to be transmitted into the form of file blocks through a preset packaging method, and a data packet can carry at least two file blocks, and the file header information of each file block is used by the receiver to receive at least part of the data of the file set and verify the correctness of a single file block in the smallest unit of the file block, so that the receiving side can independently identify whether each file block is correct, avoid discarding the entire data packet when there is an error in the data packet but part of the data is correct, and reduce the waste of link resources caused by retransmitting the entire data packet.

[0030] Implementation Method 1

[0031] This implementation manner describes optional embodiments of the present invention in conjunction with satellite and terrestrial communication networks, respectively.

[0032] For a satellite, it is configured to execute a preset satellite data transmission data processing method, see Figure 1 , including: A1, A2, A3. In order to better understand the present invention, each step is described in detail below in conjunction with specific embodiments.

[0033] Step A1: Obtain a file set to be sent to the ground communication network, and use a preset packaging method to package the file set into N file blocks, each file block includes file header information and file data information, N≥1, wherein the file header information is used by the receiver to obtain at least part of the data of the file set with the file block as the smallest unit and to verify the correctness of a single file block.

[0034] According to an embodiment of the present invention, when a satellite is in orbit, it may collect different information, and the collected information will be stored in a prescribed format to form related files. For example: jpg pictures or txt documents, etc. According to the needs, the satellite needs to send one or more files to the receiver of the ground communication network (for example, to the ground station) to form a file set. At this time, different from the prior art, the embodiment of the present invention does not need to set the verification data of the entire data packet, that is, the verification data for the entire packet may not be set in the data packet, and the receiver does not verify the integrity of the entire packet; instead, the file set is packaged into N file blocks using a preset packaging method, and each file block includes file header information and file data information. Among them, each file header information carries description information and verification information of the file data information in the same file block, and the description information includes a file name field, a file size field and other description fields, wherein the file name field is used by the receiver to extract the file name to create a file, the file size field is used by the receiver to read the data corresponding to the file size into the created file, and other description fields are used by the receiver to extract other description related information to modify the attributes of the created file, and the verification information is used to verify the correctness of a single file block.

[0035] According to an embodiment of the present invention, the preset packaging method can be improved by using an existing packaging algorithm. For example, the preset file packaging method includes using an improved Tar packaging algorithm to package a file set, wherein the verification information in each file block in the improved Tar packaging algorithm is calculated using all contents other than the verification field of the file block. The existing Tar packaging algorithm verifies the file header information packaged by the Tar packaging algorithm, and is not used to verify the file data information. Figure 2 When the improved Tar packaging algorithm is used, the package format after packaging the data is:

[0036] A. File header information:

[0037] Each file has a 512-byte header, which contains metadata such as file name, permissions, owner, group, file size, last modification time, etc. A schematic file header is shown in Table 1:

[0038] Table 1

[0039] Serial number Fields Size (bytes) 1 file name 100 2 File permissions 8 3 Owner ID 8 4 Group ID 8 5 File size 12 6 Last modified time 12 7 Checksum 8 8 File type flags 1 9 Link Name 100 10 magic number 6 11 Version 2 12 Owner Username 32 13 Owner Group Name 32 14 Major device number 8 15 Minor device number 8 16 Prefix 155 17 spare 12

[0040] The functions of each field are as follows:

[0041] 1. File name (100 bytes): The path and name of the storage file.

[0042] 2. File permissions (8 bytes): Permission flags in octal format, such as 644, 755, etc.

[0043] 3. User ID (8 bytes): User ID of the file owner.

[0044] 4. Group ID (8 bytes): The group ID to which the file owner belongs.

[0045] 5. File size (12 bytes): The file size (number of bytes) expressed in octal.

[0046] 6. Last modification time (12 bytes): The timestamp of the last modification time of the file, in UNIX time format in seconds.

[0047] 7. Checksum (8 bytes): used to verify whether the file header information and file data information of the current file block are correct, expressed in octal.

[0048] 8. File type (1 byte): The types included are: 0: ordinary file, 1: hard link, 2: symbolic link, 3: character device, 4: block device, 5: directory, 6: FIFO, other: extended type, etc.

[0049] 9. Link name (100 bytes): If it is a symbolic link or hard link, this field stores the target file path.

[0050] 10. Magic number (6 bytes): The identifier of the stored tar file, usually ustar (UNIX standard tar format).

[0051] 11. Version (2 bytes): indicates the version number.

[0052] 12. Owner User Name (32 bytes): User name of the file owner.

[0053] 13. Owner group name (32 bytes): The name of the group to which the file owner belongs.

[0054] 14. Major device number (8 bytes): If it is a special device file, this field stores the major device number (expressed in octal).

[0055] 15. Minor device number (8 bytes): If it is a special device file, this field stores the minor device number (expressed in octal).

[0056] 16. File name prefix (155 bytes): When the file name exceeds 100 bytes, it is used to store the prefix part of the file path.

[0057] 17. Reserve (12 bytes): This field is reserved for use as a reserve field. When not enabled, it can be filled with empty bytes to align to the 512-byte size.

[0058] It should be noted that when the preset packaging method is implemented using the tar packaging algorithm, the checksum field is used to record the checksum information, and the remaining fields are used to record the description information of the file data information. Among the remaining fields, the fields other than the file name field and the file size field record other description information.

[0059] B. File data information:

[0060] The file data information (or data block) follows the header information and is used to store at least part of the data content of the file. The file size is also 512 bytes. If the file size is not an integer multiple of 512 bytes, the remaining part will be filled with null bytes.

[0061] C. Directory structure ( Figure 2 not shown):

[0062] tar preserves the directory hierarchy information, so the original directory structure can be restored when decompressing.

[0063] D. End Of File (EOF) sign ( Figure 2 not shown):

[0064] The end of the archive file usually contains two consecutive 512-byte empty blocks (i.e. a total of 1024 bytes), marking the end of the archive.

[0065] It should be noted that the above packaging algorithm and Table 1 are only illustrative, and implementers can adjust them as needed to obtain other similar alternatives. For example, the zip algorithm or rar algorithm can be improved to implement the preset packaging method. Another example is that the length of a single file header information or a single file data information can be adjusted, or the field definition or field order in a single file header information can be adjusted, or other fields can be added to a single file header information, such as the number field of the entire file block. In addition, in addition to the file block, the data packet may also add some additional fields required by the existing communication protocol, such as the packet header of the data packet ( Figure 2 Not shown) to complete the transmission and reception of data.

[0066] Step A2: Encapsulating the N file blocks into M data packets, wherein each data packet is configured to be able to contain T file blocks, T≥2;

[0067] According to one embodiment of the present invention, each data packet can be loaded into T files, which requires at least M= data packets, of which Indicates rounding up. Of course, according to the needs of the implementer, some additional file blocks may be added to complete the required functions. For example, some packaging algorithms will add some empty file blocks at the end of all file blocks corresponding to the file set to indicate the end of the file, so the number of data packets may increase. For example: when using the Tar packaging algorithm, two 512-byte all-0 fields (empty blocks of the size of a file block) will be added to indicate the end of the file, so at least M= data packets.

[0068] Step A3: Sending the M data packets in the form of wireless signals.

[0069] According to an embodiment of the present invention, coding modulation technology and antennas may be used to send M data packets in the form of wireless signals. For example, after coding and modulating the M data packets, the wireless signals carrying the data packets are sent to the receiving area on the ground through the satellite-borne antenna.

[0070] For a ground communication network, such as a receiving party of the ground communication network (such as a handheld terminal or a ground station), it is configured to execute a data processing method, including: B1, B2, B3. In order to better understand the present invention, the ground station is taken as an example, and each step is described in detail in combination with a specific embodiment.

[0071] Step B1: Obtain a received signal corresponding to a wireless signal sent according to the aforementioned satellite digital data processing method.

[0072] According to one embodiment of the present invention, the ground station receives the wireless signal through a receiving antenna to obtain a corresponding received signal.

[0073] Step B2: extract each received data packet from the received signal, obtain at least part of the data of the file set from each received data packet with the file block as the minimum unit, verify the correctness of a single file block, and mark the correct file blocks and the erroneous file blocks.

[0074] According to one embodiment of the present invention, the ground station can extract the check information in each file block from the received data packet, and then calculate the check value based on other information in the file block except the check information, and determine whether the check value is consistent with the check information. If so, it indicates that the file block is a correct file block, otherwise it indicates that the file block is an incorrect file block. Optionally, the check information and the check value can be calculated using a checksum algorithm or a hash algorithm. For each received data packet, each file block therein is checked in this way, so as to obtain whether each file block in each received data packet is correct or incorrect.

[0075] After determining whether each file block is correct or incorrect, the correct file can be parsed. According to an embodiment of the present invention, for each file in the file set, if all file blocks related to the file are marked as correct file blocks, the file is parsed in the following manner: extract the file name from the file name field in the file header information of the related file block in the received data packet to create the file; read the data corresponding to the file size from the related file block into the created file according to the file size field; extract other description related information according to the other description field to modify the properties of the created file to obtain the parsed file.

[0076] In addition, if all the file blocks of a data packet are all wrong, the receiver will discard it. If only some of the file blocks of a data packet are wrong, the data packet will not be discarded, but only the correct file blocks and wrong file blocks in the data packet will be marked, the wrong file blocks will be shielded, and the correct file blocks will be retained.

[0077] Step B3: For each received data packet, obtain information about the erroneous file block and only request the satellite to retransmit the erroneous file block.

[0078] According to an embodiment of the present invention, the information of the erroneous file block refers to the identity information of the erroneous file block. For example, the identity information can be represented by the data packet number and the file block number. Alternatively, a globally unique number can be directly assigned to each file block to represent the identity information. After each data packet is processed, the identity information of the erroneous file block is extracted and the identity information of the erroneous file block is sent to the satellite to request the satellite to retransmit the erroneous file block.

[0079] Implementation 2:

[0080] See also Figure 3 ,Since the satellite to the ground communication link is susceptible to various interferences, such as electromagnetic interference, interference from high-energy particles, etc., the link state is unstable, which may cause the loss of some data packets. ,In order to better resist interference, it may be considered to improve the ,scheme of implementation 1.

[0081] According to one embodiment of the present invention, a method for processing satellite data transmission data is provided, which is used for a satellite, and includes:

[0082] A1': Obtain a file set to be sent to the ground communication network, and use a preset file packaging method to package the file set into N file blocks, each file block includes file header information and file data information, N≥1, wherein the file header information is used by the receiver to obtain at least part of the data of the file set with the file block as the minimum unit and to verify the correctness of a single file block;

[0083] A2': Encapsulate the N file blocks into M data packets, wherein each data packet is configured to be able to contain T file blocks, T ≥ 2;

[0084] A3': adding preset redundant data to the header and the tail of each data packet to obtain an anti-interference packet, and sending each data packet in the one or more data packets in the form of an anti-interference packet.

[0085] According to one embodiment of the present invention, see Figure 4 ,exist Figure 2 On the basis of the packet header and the packet tail, a redundant data is added to each packet. The redundant data is a specified value or a stacked specified value. The length of the redundant data is adjusted by increasing or decreasing the number of stacked specified values. The specified value is specified by the protocol. Alternatively, the specified value can be sent by the satellite to the ground communication network before each anti-interference packet is sent. For example, if the specified value is set to 0x3561, all the fields corresponding to the redundant data are filled with 0x3561.

[0086] The length of the redundant data can be fixed, for example, it can be filled with K 0x3561. However, since the interference situation of the link is variable, further improvement can be considered. According to one embodiment of the present invention, the method also includes: obtaining a plurality of levels of interference ranges and the redundant data length corresponding to each interference range, wherein the higher the level of interference range, the stronger the interference, and the longer the corresponding redundant data length; monitoring the interference intensity of the current satellite-to-ground communication link, and dynamically adjusting the length of the redundant data in the currently sent anti-interference packet according to the interference range of the interference intensity, wherein the length of the anti-interference packet is predetermined, and when the length of the redundant data is increased, the number of file blocks stacked in the data packet is reduced. The scheme can dynamically adjust the length of the redundant data according to the interference situation of the channel, so that when the interference intensity is large, relatively long redundant data is used, so that when the interference intensity is large, the probability of data packet damage is reduced, so as to reduce data retransmission; and when the interference is weak, the number of file blocks that the data packet can accommodate is increased as much as possible to ensure transmission efficiency.

[0087] Of course, the implementer can also consider other ways to adjust the length of redundant data. According to one embodiment of the present invention, the method also includes: obtaining the statistical error rate of the file blocks of the historical period feedback from the ground communication network and the interference intensity of the current satellite-to-ground communication link, and weighted summing the statistical error rate and the interference intensity to obtain a channel index; obtaining the index range of multiple levels set in advance and the redundant data length corresponding to each index range, wherein the higher the index range, the longer the redundant data length corresponding to the higher level; dynamically adjusting the length of the redundant data in the anti-interference packet currently sent according to the index range of the channel index. This scheme uses the weighted sum of the statistical error rate and the interference intensity to adjust the length of the redundant data, which can reduce the frequent adjustment of the length of the redundant data, reduce the overhead caused by the adjustment, and better ensure communication efficiency.

[0088] For a terrestrial communication network, such as a receiving side of a terrestrial communication network, compared with implementation mode 1, a step of removing redundant data is added.

[0089] See also Figure 5 According to an embodiment of the present invention, there is provided a data processing method, which is applied to a receiving party in a terrestrial communication network, and the method comprises:

[0090] B1': obtaining a received signal corresponding to a wireless signal sent according to the satellite digital data processing method in implementation mode 2;

[0091] B2': extracting each received anti-interference packet from the received signal, and removing the specified values ​​from the header and the tail of each anti-interference packet one by one according to the specified values ​​in the redundant data obtained in advance to remove the redundant data, thereby obtaining each received data packet;

[0092] B3': from each received data packet, taking a file block as the smallest unit, obtaining at least part of the data of the file set and verifying the correctness of a single file block, and marking the correct file block and the wrong file block;

[0093] B4': For each received data packet, obtain the information of the erroneous file blocks and only request the satellite to retransmit the erroneous file blocks.

[0094] The difference between this embodiment and embodiment 1 is that what is received is an anti-interference packet, and the redundant values ​​need to be removed to restore the received data packet. Since the receiver has pre-acquired the specified values ​​filled in the redundant data, after receiving the anti-interference packet, according to the specified values ​​in the pre-acquired redundant data, the specified values ​​are removed one by one from the header and the tail of each anti-interference packet to remove the redundant data, and each received data packet is obtained.

[0095] Implementation 3

[0096] Since checking each file block separately for each data packet may increase the overhead, further improvement schemes may be considered.

[0097] According to one embodiment of the present invention, in a method for processing satellite data transmission, each data packet sent is provided with packet verification data for performing integrity verification on the entire data packet. At the receiving end, the integrity of the entire data packet is first verified according to the packet verification data. If the entire packet verification passes, all file blocks of the data packet are directly marked as correct file blocks. Otherwise, the correctness of each file block of the data packet is independently verified.

[0098] Implementation 4

[0099] The present implementation method provides a satellite-to-ground communication system, including: a satellite and ground equipment. The satellite is configured to: obtain a file set to be sent to a ground communication network, and use a preset file packaging method to package the file set into multiple file blocks, each file block including file header information and file data information, wherein the file header information is used by the receiver to obtain at least part of the data of the file set and verify the correctness of a single file block with the file block as the minimum unit; encapsulate the multiple file blocks into one or more data packets, wherein each data packet is configured to be able to load T (T can be set to 2, 4, 8, 10, 20, etc.) file blocks; add preset redundant data to the header and tail of each data packet to obtain an anti-interference packet, and send each data packet in the one or more data packets in the form of an anti-interference packet.

[0100] The ground device is configured to: obtain a received signal corresponding to the wireless signal sent by the satellite; extract each received anti-interference packet from the received signal, and remove the specified values ​​from the header and the tail of each anti-interference packet one by one according to the specified values ​​in the redundant data obtained in advance to remove the redundant data, so as to obtain each received data packet; from each received data packet, obtain at least part of the data of the file set with the file block as the minimum unit and verify the correctness of a single file block, and mark the correct file block and the erroneous file block; for each received data packet, obtain the information of the erroneous file block, and only request the satellite to retransmit the erroneous file block.

[0101] In this system, the overall function realization includes three main stages. The first stage is data packaging and redundant information addition. The second stage is the data packet transmitted to the ground through the data transmission link. The third stage is the ground equipment parsing and processing the received data packet. The following is a brief introduction to the three stages through an example:

[0102] Phase 1: Data Packaging and Redundancy Addition

[0103] Before data transmission, the satellite first packages and processes all types of data that need to be transmitted. During the data packaging process, specific redundant information is added before and after the data packet. The purpose of this design is to enhance the ability of data packets to resist interference and packet loss during transmission, and to reduce the damage and loss of valid data by adding redundant information. At the beginning and end of the satellite-to-ground link transmission, large link jitter can easily cause data loss. Placing redundant data before and after can protect the valid data in the middle. The data lost during the jitter time is also the redundant data before and after the loss, which reduces the probability of losing valid data.

[0104] Phase 2: Data packets are transmitted to the ground via a data link

[0105] During the data transmission process between the satellite and the ground equipment, the packaged data packets are transmitted through the communication link. Due to the complexity of the space environment, the link is often subject to various interferences, such as electromagnetic waves, changing weather conditions, signal attenuation, etc., which may cause part of the data packet to be lost or bit reversal errors to occur. At this stage, the system's anti-interference design and redundant data begin to play a role, ensuring that most data packets can reach the ground equipment smoothly even in the case of poor links.

[0106] Phase 3: Ground equipment parses and processes received data packets

[0107] When the ground equipment receives the data packet transmitted from the satellite, it first performs preliminary processing on the data packet to remove the redundant data in the packet header and the packet tail. This step mainly removes the redundant information attached to the original data so that the data packet is restored to its original state. Next, according to the file header information in the data packet (such as file type, size, etc.), the actual data file will be intelligently extracted. During the extraction process, even if part of the data packet content is irreversibly damaged, valid data fragments can still be obtained from it to avoid overall discarding and maximize the use of transmission resources. For example, the tar command is used to package data when the satellite is packaged.

[0108] The third stage includes: removing redundant data, extracting valid data from the file, and determining whether the file is damaged.

[0109] (1) Remove redundant data

[0110] First, after receiving the data packet, the ground equipment needs to remove the redundant data added in the packet header and packet tail during transmission. Redundant data is usually added in the form of repeated units, so the data packet content will be read step by step according to the preset redundant data format and length. The specific operation is to read the data stream in a fixed length one by one and perform multiple repeated matches. If the specified value is 0XAA11, then two bytes are read each time; if the specified value is 0xaa112233, then four bytes are read each time for comparison; if the read data is equal to the redundant fixed value, it is considered that the current read data is redundant data and needs to be removed. Repeating the above operation can remove redundant data, which is multiple repeated matches. When the redundant data match is detected, the redundant part will be skipped and the empty data will continue to be read until the start position of the valid data is detected. At this time, the current position will be recorded and marked as the valid data header of the file. This step ensures that the redundant information is correctly removed and prepares for the subsequent extraction of valid data.

[0111] (2) Extract valid data from files

[0112] The satellite uses tar to pack data, which is usually stored in 512-byte blocks. Therefore, the extraction process starts with the marked file payload header and reads data step by step in 512-byte units. Common data file name suffixes, such as ".txt", ".jpg", etc., are searched in these blocks, and the offset relative to the file payload header is determined by matching the position of the file name suffix.

[0113] Once the relative position of the file name suffix is ​​determined, the file header information (512 bytes) will be located according to the standard tar package storage format, and the size information of the current file will be extracted from it. Next, the data is read block by block according to the file size until the EOF (End of File) mark indicating the end of the file is read, that is, two consecutive 512-byte empty blocks. During this process, the system ensures that each block of data is extracted strictly in accordance with the tar format and records the integrity information of the file.

[0114] (3) Determine whether the file is damaged

[0115] In order to determine whether the extracted data file is damaged, the file description information in each 512-byte block is checked. Schematically, the ground equipment will check the group ID, owner ID and other fields, and further verify based on the suffix type of the file name. The data format of different file types has its own characteristics. For example, the header of a JPG image file has a specific identifier (FFD8FF). By reading the file header information and comparing it with the standard format, it is determined whether the file is intact.

[0116] If the file description information or data format verification fails, it means that the current file data may be damaged. At this time, the exception will be recorded and an attempt will be made to skip the file and continue to process subsequent data. The verification process is performed block by block to ensure the data integrity of each file segment. The ground equipment will read the file header information, extract the file data, and perform necessary verification in sequence until the entire tar data packet is processed. After this process, lossless data will be successfully extracted, and damaged data will be marked and isolated.

[0117] In general, the method of the present invention realizes an efficient and reliable damaged data analysis and fault tolerance technology in the satellite-to-ground communication system. Different from the traditional data analysis method, this scheme can not only better extract valid data in complex environments, but also flexibly deal with the situation where some data is damaged, ensuring the maximum utilization of data transmission link resources.

[0118] It should be noted that although the above describes the various steps in a specific order, it does not mean that the various steps must be executed in the above specific order. In fact, some of these steps can be executed concurrently or even in a different order as long as the required functions can be achieved.

[0119] The present invention may be a system, a method and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present invention.

[0120] A computer-readable storage medium may be a tangible device that holds and stores instructions used by an instruction execution device. Computer-readable storage media may include, for example, but are not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination thereof. More specific examples (non-exhaustive list) of computer-readable storage media include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, such as a punch card or a protruding structure in a groove on which instructions are stored, and any suitable combination thereof.

[0121] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A method for processing satellite data transmission, used for a satellite, characterized in that: include: Obtain a file set to be sent to a ground communication network, and package the file set into N file blocks using a preset packaging method, each file block including file header information and file data information, N≥1, wherein the file header information is used by the receiver to obtain at least part of the data of the file set with the file block as the minimum unit and to verify the correctness of a single file block; Encapsulating the N file blocks into one or more data packets, wherein each data packet is configured to be able to contain T file blocks, T≥2; The one or more data packets are sent out in the form of wireless signals.

2. The method according to claim 1, characterized in that Each file header information carries description information and verification information of the file data information in the same file block, wherein the description information includes a file name field, a file size field and other description fields, wherein the file name field is used by the recipient to extract the file name to create a file, the file size field is used by the recipient to read data corresponding to the file size into the created file, the other description fields are used by the recipient to extract other description related information to modify the properties of the created file, and the verification information is used to verify the correctness of a single file block.

3. The method according to claim 1, characterized in that The preset file packaging method includes using an improved Tar packaging algorithm to package a file set, wherein the check information in each file block in the improved Tar packaging algorithm is calculated using all contents except the check field of the file block.

4. The method according to claim 4, characterized in that: The verification information is a checksum or hash value calculated using all contents except the verification field of the file block.

5. The method according to any one of claims 1 to 4, characterized in that: Before sending the one or more data packets in the form of wireless signals, preset redundant data is added to the header and the tail of each data packet to obtain an anti-interference packet, and each data packet is sent in the form of an anti-interference packet.

6. The method according to claim 5, characterized in that The method further comprises: Obtaining interference ranges of multiple levels preset and redundant data lengths corresponding to each interference range, wherein a higher level of interference range represents stronger interference and a corresponding redundant data length is relatively longer; Monitor the interference intensity of the current satellite-to-ground communication link, and dynamically adjust the length of redundant data in the currently sent anti-interference packet according to the interference range of the interference intensity, wherein the length of the anti-interference packet is predetermined, and when the length of the redundant data is increased, the number of stacked file blocks in the data packet is reduced.

7. The method according to claim 5, characterized in that The redundant data is a specified value or a stacked specified value, and the length of the redundant data is adjusted by increasing or decreasing the number of stacked specified values. The specified value is specified by the protocol or sent by the satellite to the ground communication network before sending an anti-interference packet each time.

8. A data processing method, applied to a receiver in a terrestrial communication network, comprising: Acquire a received signal corresponding to a wireless signal sent according to the method of any one of claims 1 to 7; Extracting each received data packet from the received signal, obtaining at least part of the data of the file set from each received data packet with the file block as the minimum unit and verifying the correctness of a single file block, and marking the correct file block and the wrong file block; For each data packet received, the information of the erroneous file blocks is obtained, and only the erroneous file blocks are requested to be retransmitted by the satellite.

9. The method according to claim 8, characterized in that Each file header information carries description information of the file data information in the same file block, and the description information includes a file name field, a file size field and other description fields. Among them, for each file in the file set, if all file blocks related to the file are marked as correct file blocks, the file is parsed in the following manner: Extracting the file name from the file name field in the file header information of the relevant file block in the received data packet to create a file; According to the file size field, read the data corresponding to the file size from the relevant file block into the created file; According to other description fields, other description related information is extracted to modify the properties of the created file to obtain the parsed file.

10. A satellite-to-ground communication system, comprising: A satellite for implementing the method according to any one of claims 1 to 7, configured as follows: Obtain a file set to be sent to the ground communication network, and use a preset file packaging method to package the file set into N file blocks, each file block includes file header information and file data information, N≥1, wherein the file header information is used by the receiver to obtain at least part of the data of the file set with the file block as the minimum unit and to verify the correctness of a single file block; Encapsulating the N file blocks into one or more data packets, wherein each data packet is configured to be able to contain T file blocks, T≥2; Adding preset redundant data to the header and the tail of each data packet to obtain an anti-interference packet, and sending each data packet in the one or more data packets in the form of an anti-interference packet; A ground device for implementing the method as claimed in claim 8 or 9, which is configured as follows: Acquire a received signal corresponding to the wireless signal sent by the satellite; Extracting each received anti-interference packet from the received signal, and removing the specified values ​​from the header and the tail of each anti-interference packet one by one according to the specified values ​​in the redundant data obtained in advance to remove the redundant data, thereby obtaining each received data packet; From each received data packet, taking a file block as the smallest unit, obtaining at least part of the data of the file set and verifying the correctness of a single file block, and marking a correct file block and an erroneous file block; For each data packet received, the information of the erroneous file blocks is obtained, and only the erroneous file blocks are requested to be retransmitted by the satellite.

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