A method for satellite-ground cooperative data distribution based on RaptorQ code

Abstract

The application discloses a kind of star-ground cooperative data distribution methods based on RaptorQ code, it is related to satellite communication and integrated space-ground communication technical field.The application discloses a kind of star-ground cooperative data distribution methods based on RaptorQ code, it is related to satellite communication and integrated space-ground communication technical field.The application discloses a kind of star-ground cooperative data distribution methods based on RaptorQ code, it is related to satellite communication and integrated space-ground communication technical field.The application discloses a kind of star-ground cooperative data distribution methods based on RaptorQ code, it is related to satellite communication and integrated space-ground communication technical field.The application discloses a kind of star-ground cooperative data distribution methods based on RaptorQ code, it is related to satellite communication and integrated space-ground communication technical field.The application discloses a kind of star-ground cooperative data distribution methods based on RaptorQ code, it is related to satellite communication and integrated space-ground communication technical field.The application discloses a kind of star-ground cooperative data distribution methods based on RaptorQ code, it is related to satellite communication and integrated space-ground communication technical field.The application discloses a kind of star-ground cooperative data distribution methods based on RaptorQ code, it is related to satellite communication and integrated space-ground communication technical field.The application discloses a kind of star-ground cooperative data distribution methods based on RaptorQ code, it is related to satellite communication and integrated space-ground communication technical field.The application discloses a kind of star-ground cooperative data distribution methods based on RaptorQ code, it is related to satellite communication and integrated space-ground communication technical field.

Description

Technical Field

[0001] This invention relates to the fields of satellite communication and space-ground integrated communication technology, and in particular to a satellite-ground collaborative data distribution method based on RaptorQ codes. Background Technology

[0002] With the development of satellite internet and integrated space-air-ground information networks, satellite communication networks and terrestrial communication networks are gradually forming a converged and collaborative network system. Satellite networks have advantages such as wide coverage and high multicast efficiency, while terrestrial networks have characteristics such as low latency and abundant bandwidth resources. Distributing massive amounts of content data through satellite-terrestrial collaboration can effectively improve network coverage and data service capabilities. However, because satellite links are susceptible to factors such as weather conditions, terminal location, and channel fading, the link quality between different edge nodes varies significantly. This can lead to problems such as data loss, frequent retransmissions, and decreased resource utilization during data distribution, thus affecting overall distribution efficiency.

[0003] To improve data distribution efficiency in satellite-ground cooperative networks, existing technologies have been researched. For example, Chinese patent application CN109412950B, "Data Distribution Method Based on On-Path Caching in Satellite-Ground Hybrid Networks," reduces data acquisition latency and transmission overhead by constructing a cross-timeslot connection graph and a cache node selection mechanism, utilizing path caching. Another Chinese patent application, CN110838897A, "High-Efficiency Network Coding HARQ Transmission Mechanism for Downlink Multicast Scenarios in Space Information Networks," combines HARQ with network coding, improving multicast transmission reliability through receiver feedback and coded retransmission. These two technologies improve data distribution performance in satellite-ground cooperative networks from the perspectives of cache routing optimization and reliable transmission optimization, respectively.

[0004] However, the above solutions still have certain shortcomings. CN109412950B mainly focuses on cache deployment and routing optimization, lacking a design for reliable data distribution under link packet loss environments; while CN110838897A can reduce some retransmission overhead, it still relies on receiver feedback and retransmission mechanisms, which can easily lead to high coordination overhead and transmission latency in large-scale user scenarios. Furthermore, none of the existing technologies fully consider the redundant resource configuration issues caused by differences in link quality among different receiving nodes.

[0005] How to solve the above-mentioned technical problems is the challenge facing this invention. Summary of the Invention

[0006] The purpose of this invention is to provide a satellite-ground collaborative data distribution method based on RaptorQ codes. By combining satellite multicast and ground unicast distribution and re-spraying strategies, dynamic configuration of coding redundancy and differentiated re-sending of coding symbols are achieved, thereby reducing network overhead and improving the efficiency of satellite-ground collaborative data distribution while ensuring reliable transmission.

[0007] The inventive concept of this invention is as follows: This invention provides a satellite-ground collaborative data distribution method based on RaptorQ codes. It constructs a satellite-ground collaborative data distribution network architecture consisting of a data center, satellite links, ground links, and edge receivers. It introduces RaptorQ code encoding and decoding technology, which has no code rate characteristics, as an application-layer forward error correction scheme. Combining the wide-area coverage advantage of satellite multicast with the low latency and high bandwidth advantage of ground unicast, it designs a collaborative distribution strategy including fixed-rate first-spray and over-rate first-spray, and a collaborative supplementary spray strategy including fixed-rate supplementary spray and over-rate supplementary spray, based on the log-normal distribution characteristics of the satellite link packet loss rate. This achieves improved data distribution efficiency and reduced network overhead in a satellite-ground collaborative communication environment.

[0008] To achieve the aforementioned objectives, the present invention employs the following technical solution: a satellite-ground collaborative data distribution method based on RaptorQ codes, comprising the following steps:

[0009] Step S01: Construct a satellite-ground collaborative data distribution system to distribute probe data via satellite link multicast and obtain the initial quality status of satellite links at each edge.

[0010] Step S02: Read the encoding parameters of the local RaptorQ code and calculate the encoding redundancy of the first distribution based on the packet loss rate of each edge satellite link.

[0011] Step S03: Generate the quota first spray symbol and the excess first spray symbol according to the satellite-ground collaborative distribution strategy, and distribute the data.

[0012] Step S04: Receive supplementary spraying requests and real-time link quality from each edge terminal, generate quota supplementary spraying symbols and excess supplementary spraying symbols according to the satellite-ground collaborative supplementary spraying strategy, and perform data supplementary spraying.

[0013] Furthermore, the satellite-ground collaborative data distribution system described in step S01, such as Figure 2As shown, the system includes a data center, satellite links, terrestrial links, and edge receivers. The satellite links are used for multicast communication, while the terrestrial links are used for unicast communication. Edge receivers simultaneously access both the satellite and terrestrial links via multi-link devices, achieving a satellite-ground collaborative network. The probe data is used for initial link quality detection. It is multicasted to each edge receiver via the satellite link, and each edge receiver then feeds back the real-time satellite link quality status (including packet loss rate and latency) to the data center via the terrestrial link. This data supports subsequent calculations of coding redundancy and the development of distribution strategies.

[0014] Furthermore, the RaptorQ code described in step S02 is an efficient error correction coding technique with no code rate characteristics. It can be used as an application layer FEC (AL-FEC) scheme, and is particularly suitable for multicast scenarios in satellite communication and mobile networks. It can optimize bandwidth utilization efficiency while ensuring reliable data distribution. Figure 3 The packet loss rate is given for different coding redundancy rates under the condition that the Raptor Q code length K is 512 and the data packet length L is 1024. With decoding success rate The relationship curve satisfies the requirements of the link. In actual data distribution, the coding redundancy in the satellite-ground collaborative data distribution process can be dynamically adjusted based on the specific packet loss situation of the link and the system's requirements for decoding success rate, referring to the relationship between packet loss rate, redundancy rate, and decoding success rate. :

[0015] (1);

[0016] in, The dynamic redundancy optimization coefficient is obtained through offline simulation analysis and curve fitting of the relationship between packet loss rate, redundancy rate and decoding success rate of RaptorQ code, thereby improving the decoding accuracy at the edge.

[0017] Furthermore, the link packet loss rate corresponding to each edge terminal mentioned in step S02 varies significantly due to factors such as geographical location, weather conditions, and satellite terminal power. Statistical analysis shows that the link packet loss rate of each edge terminal... It can be approximated as following a log-normal distribution, and its probability density function is expressed as follows:

[0018] (2);

[0019] in, The probability density function that represents the packet loss rate of the link is satisfied by. It is the mean of the logarithmic packet loss rate, i.e. = ; It is the standard deviation of the logarithmic packet loss rate, representing the range of fluctuation of the logarithmic packet loss rate.

[0020] Based on the quantile characteristics of the log-normal distribution, the quantile method can be used to determine reference values ​​for high packet loss rates, and... Packet loss rate at quantiles satisfy:

[0021] (3);

[0022] in, The upper part of the standard normal distribution quantiles; This refers to the terminal coverage ratio, the specific value of which can be flexibly determined based on service reliability requirements and network resource conditions. It is recommended that the confidence level meet the requirements. Selecting a packet loss rate threshold within this range can reflect the mainstream trend in the dataset and effectively exclude outliers with excessively high packet loss rates.

[0023] Therefore, based on the quantile characteristics of the packet loss rate distribution, select Using the value at this point as a reference value for generating the quota first spray symbol, the expression for the coding redundancy of the quota first spray symbol can be obtained as follows:

[0024] (4);

[0025] in, This indicates that the quota code is redundant.

[0026] By selecting the maximum packet loss rate as the reference value for generating the excess first spray symbol, the coding redundancy r of the excess first spray symbol can be obtained. od The expression is:

[0027] (5);

[0028] in, This indicates excessive coding redundancy. This indicates the maximum packet loss rate in the link.

[0029] Furthermore, the satellite-to-ground collaborative distribution strategy described in step S03, such as Figure 4 The file to be distributed is divided into blocks and then a fixed-quota first-spray symbol and an excess first-spray symbol are generated based on the RaptorQ code encoding rules. The fixed-quota first-spray symbol is distributed to all edge terminals through a satellite multicast link, and the excess first-spray symbol is transmitted to edge terminals with high packet loss rate through a terrestrial unicast link.

[0030] According to the encoding rules of RaptorQ code, the quota first spray symbol of the satellite-ground collaborative data distribution mechanism is known. sequence length for:

[0031] (6);

[0032] in, Symbol for first spray of quota The sequence length, The code length of the Raptor Q code. This corresponds to the extended code length.

[0033] First spray mark of quota This data is distributed via satellite link multicast to all edge devices within the system, ensuring its availability within the system. At the edge, successful decoding can be achieved during the initial distribution process.

[0034] Excess first spray symbol of the satellite-ground collaborative data distribution mechanism Maximum sequence length for:

[0035] (7);

[0036] in, Symbol indicating excess first spray The maximum sequence length.

[0037] Excess First Spray Symbol The packet loss rate of unicast transmission via ground link to the system At the edge, as a supplement to the initial spray symbol, it ensures that even edge devices with abnormal packet loss rates can achieve complete decoding during the initial distribution process. Simultaneously, the satellite-ground collaborative distribution strategy provides targeted data retransmission based on the packet loss rate of specific edge devices, through at most... An extra first-spray symbol is reissued to achieve complete decoding of all edge ends.

[0038] Therefore, the number of symbols in a single block during the initial distribution process is:

[0039] (8);

[0040] in, Indicates the number of symbols in a single block. Indicates the first The number of excess first spray symbols corresponding to each edge end.

[0041] Furthermore, the satellite-ground coordinated supplementary injection strategy described in step S04 is used to address the problem that unstable satellite links prevent edge terminals from fully receiving and distributing coded symbols, thus hindering complete decoding. For example... Figure 5 As shown, the data center generates quota spraying symbols and excess spraying symbols based on the spraying requests fed back by each edge terminal. The quota spraying symbols are distributed to all edge terminals through satellite multicast links, while the excess spraying symbols are transmitted to edge terminals with high packet loss rates through terrestrial unicast links.

[0042] After a round of data distribution is completed, the data center monitors the packet replenishment requests from the edge devices in real time and organizes the replenishment request sequence from each edge device into blocks, that is, it counts the number of edge devices that need to replenish each file block. Then, based on the quantile characteristics of the log-normal distribution, determine... and The size relationship determines how to distribute the goods.

[0043] In addition, in the satellite-ground coordinated supplementary spray strategy, the packet number of the supplementary spray encoded data An incremental approach is adopted to avoid out-of-order distribution and to facilitate edge-end decoding and statistical decoding results.

[0044] (1) When = 0: This means that the data center has not received a data patching request frame for the current file block, so there is no need to perform data patching operation on this block.

[0045] (2) When : Indicates the percentage of edges that need respraying out of the total number of edges. Within this scope, only the overspray symbol needs to be generated. And it is transmitted to the designated edge only through the terrestrial communication link.

[0046] Calculate the packet loss rate at the edge of the link that needs to be re-sprayed for each file block. The number of packets requiring additional spraying is calculated by selecting the packet loss rate with the highest value, resulting in the number of excess spraying symbols:

[0047] (9);

[0048] in, Symbol indicating overspray The sequence length, This indicates the number of re-spray packages required for each file block.

[0049] The satellite-ground coordinated data replenishment strategy provides targeted data replenishment based on the packet loss rate at specific edge devices, through up to [number missing] [unclear text - possibly related to data replenishment]. The transmission of each overspray symbol ensures the integrity of data at each edge and achieves complete decoding.

[0050] (3) When : Indicates that the number of edges requiring repainting exceeds the total number of edges. This requires combining satellite multicast and terrestrial unicast communication methods to complete the data replenishment work, in order to improve the efficiency of data replenishment.

[0051] Calculate the packet loss rate at the edge of the link that needs to be re-sprayed for each file block. and the number of packs that need to be re-sprayed and to Sort the packet loss rates at each edge and select the 1st edge. The packet loss rate at each edge is used as the symbol for calculating the quota for refilling. Use the reference value to select the maximum packet loss rate. As a symbol for calculating excess spraying Reference values.

[0052] remember = = Then, referring to formula (1), we can obtain:

[0053] (10);

[0054] (11);

[0055] in, Symbol for fixed-quota respray The sequence length, Indicates the first Packet loss rate at the edge.

[0056] In this scenario, the satellite-ground coordinated spraying strategy is distributed via satellite multicast links. A fixed-quota respray symbol is used to achieve a lower packet loss rate. The edge devices can successfully decode in this round; at the same time, in order to ensure that even a few edge devices with abnormal packet loss rates can successfully decode in this round of supplementary spraying, the satellite-ground coordinated supplementary spraying strategy will unicast excess supplementary spraying symbols through the ground link, and provide targeted data supplementary spraying according to the packet loss rate of specific edge devices, through at most The over-spraying of symbols enables complete decoding of all edge ends in this round.

[0057] Therefore, the number of symbols per block during the respraying process is:

[0058] (12);

[0059] in, This indicates the number of symbols per block during the retouching process. This represents the number of excess spray symbols corresponding to the i-th edge.

[0060] Meanwhile, this invention proposes a satellite-ground collaborative data distribution system based on RaptorQ codes. The system, applying the method described in this invention, includes the following steps:

[0061] The satellite-ground collaborative data distribution building module is configured to perform the following process: distribute probe data via satellite link multicast and obtain the initial quality status of each edge satellite link;

[0062] The read module is configured to perform the following process: read the encoding parameters of the local RaptorQ code and calculate the encoding redundancy of the initial distribution based on the packet loss rate of each edge satellite link;

[0063] The data distribution module is configured to perform the following process: generate quota first spray symbols and excess first spray symbols according to the satellite-ground collaborative distribution strategy, and then distribute the data.

[0064] The data supplementation module is configured to perform the following process: receive supplementation requests and real-time link quality from each edge terminal, generate quota supplementation symbols and excess supplementation symbols according to the satellite-ground collaborative supplementation strategy, and perform data supplementation.

[0065] Meanwhile, the present invention proposes an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the computer program is executed, it implements the steps of the method described in the present invention.

[0066] Furthermore, the present invention proposes a computer-readable storage medium having a computer program stored thereon, the computer program being configured to implement the steps of the method described in the present invention when invoked by a processor.

[0067] Finally, the present invention provides a computer program product comprising a computer program / instructions that, when executed by a processor, implement the steps of the method described in the present invention.

[0068] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0069] (1) This invention introduces RaptorQ codes, which have rate-insensitive characteristics, as an application-layer forward error correction technology. Combining the advantages of satellite multicast and terrestrial unicast, it designs targeted distribution and supplementary error correction strategies. Simulation experiments show that as the user base increases, the coordination frequency of this invention remains lower than that of existing technologies and tends to stabilize in large-scale user scenarios. This indicates that this invention can significantly reduce the coordination frequency during data distribution and effectively improve coordination efficiency in satellite-terrestrial collaborative communication environments.

[0070] (2) Based on the log-normal distribution characteristics of link packet loss rate, this invention uses the quantile method to dynamically determine coding redundancy, avoiding the problems of insufficient or excessive redundancy caused by using average or maximum packet loss rate in existing technologies. Experimental results show that as the user scale increases, the network overhead of existing technologies shows a significant upward trend, while the network overhead of this invention remains stable. Even in low-user-scale scenarios, this invention achieves a significant reduction in coordination frequency by moderately increasing network overhead, thus optimizing the overall utilization efficiency of network resources.

[0071] (3) This invention, through the rate-free characteristics and forward error correction capability of RaptorQ codes, can recover the complete original information even when some data packets are lost at the receiving end. It is particularly suitable for scenarios where satellite communication links are unstable and susceptible to signal attenuation and environmental interference. At the same time, this invention provides targeted over-spray symbols and supplementary spray symbols according to the actual packet loss rate of each edge end. This ensures that most normal edge ends complete decoding in the first distribution, while also ensuring that a few edge ends with abnormal packet loss rates achieve complete decoding through subsequent supplementary spraying. This balances the overall reliability of the system and its adaptability to heterogeneous link environments. Attached Figure Description

[0072] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof.

[0073] Figure 1 The flowchart illustrates a satellite-ground collaborative data distribution method based on RaptorQ codes provided by this invention.

[0074] Figure 2 This is a diagram of the satellite-ground collaborative data distribution network architecture provided by the present invention.

[0075] Figure 3 The RaptorQ code packet loss rate-decoding success rate curves under different redundancy rates provided by this invention.

[0076] Figure 4 This is a diagram illustrating the satellite-ground collaborative distribution strategy provided by the present invention.

[0077] Figure 5 This is a diagram of the satellite-ground coordinated supplementary spray strategy provided by the present invention.

[0078] Figure 6 This invention provides a comparison chart of the frequency of collaboration under different packet loss rates.

[0079] Among them, (a) is a comparison chart of the frequency of collaboration when the mean logarithmic packet loss rate is 0.01; (b) is a comparison chart of the frequency of collaboration when the mean logarithmic packet loss rate is 0.05; and (c) is a comparison chart of the frequency of collaboration when the mean logarithmic packet loss rate is 0.1.

[0080] Figure 7 The network overhead comparison charts provided by the present invention under different packet loss rates are shown below; (a) is a network overhead comparison chart when the mean logarithmic packet loss rate is 0.01; (b) is a network overhead comparison chart when the mean logarithmic packet loss rate is 0.05; and (c) is a network overhead comparison chart when the mean logarithmic packet loss rate is 0.1. Detailed Implementation

[0081] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. Of course, the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0082] Example 1: In this example, to evaluate the collaborative efficiency performance of the proposed satellite-ground collaborative data distribution mechanism, two typical satellite multicast hybrid automatic repeat request (HARQ) mechanisms are selected as comparison schemes: a satellite multicast HARQ mechanism with redundancy configured based on average packet loss rate and a satellite multicast HARQ mechanism with redundancy configured based on maximum packet loss rate. This example uses multiple sets of comparative simulation experiments to analyze the impact of each collaborative mechanism on data distribution collaborative efficiency under different user scale scenarios, thereby demonstrating the superior performance of the proposed mechanism.

[0083] This embodiment uses the MATLAB simulation platform to build a simulation experimental model adapted to the technical solution of this invention. In the simulation experimental model, the packet loss rate of the edge link is set to follow a log-normal distribution to accurately simulate the link transmission characteristics and environmental conditions of real satellite networks. To quantitatively analyze the impact of user scale on the performance of the collaborative distribution mechanism, this simulation experiment sets up five user scale scenarios with different gradients, and performs 10 simulations for each scenario. 3 Multiple independent replicate experiments ensure that the experimental results have statistical validity, stability and reliability.

[0084] In the data distribution process of this invention, a single data distribution operation at the data center and the subsequent feedback response operation at the edge constitute a satellite-ground collaborative behavior; wherein, the lower the frequency of collaboration, the higher the collaborative transmission efficiency of the corresponding data distribution mechanism. In this experiment, the code length of the RaptorQ code is set to [value missing]. The length is 1024. Also 1024, the distributed file size is 100M, the quantile of the log-normal distribution. For three different logarithmic packet loss rate mean values ​​of 0.01, 0.05, and 0.1, the cooperative frequency index of each mechanism was tested, and the corresponding experimental results are as follows: Figure 6 (a) Figure 6 (b) Figure 6 As shown in (c).

[0085] Analysis of the coordination frequency simulation results under three different packet loss rate environments shows that:

[0086] Regarding horizontal scalability, as the user base continues to grow, the traditional satellite multicast HARQ mechanism, which uses redundancy based on average packet loss rate, exhibits a significant increase in its coordination frequency, indicating that its performance is heavily influenced by network load. In contrast, the coordination frequency of the HARQ mechanism based on maximum packet loss rate and the satellite-ground collaborative data distribution mechanism proposed in this invention remains relatively stable across different user scales, and tends to saturate when the number of users is large. This fully demonstrates that in large-scale user access scenarios, this invention possesses superior performance and collaborative transmission efficiency, effectively suppressing the runaway overhead caused by increasing load.

[0087] Regarding longitudinal robustness, a comparison of test results corresponding to different mean packet loss rates shows that as the mean logarithmic packet loss rate increases (i.e., the channel environment deteriorates), although the coordination frequency of each method increases, the performance advantage of this invention over the traditional HARQ mechanism becomes increasingly significant. Especially in harsh scenarios with high packet loss rates (mean 0.1%), when the coordination frequency of the traditional HARQ mechanism rises sharply, this invention can still maintain the coordination frequency at a low and stable level. This result strongly verifies that this invention still possesses extremely strong environmental adaptability and robustness under poor link quality conditions, and its transmission stability and adaptability are significantly superior to existing traditional mechanisms.

[0088] Example 2: In this example, to evaluate the network overhead performance of the proposed satellite-ground cooperative data distribution mechanism, two typical satellite multicast hybrid automatic repeat request (HARQ) mechanisms mentioned in Example 1 are selected as comparison schemes. This example uses multiple sets of comparative simulation experiments to analyze the impact of each cooperative mechanism on the data distribution network overhead under different user scale scenarios, thereby demonstrating the superior performance of the proposed mechanism.

[0089] In this embodiment, a simulation model adapted to the technical solution of this invention is also built based on the MATLAB simulation platform. In the simulation model, the packet loss rate of the edge link is set to follow a log-normal distribution to accurately simulate the link transmission characteristics and environmental conditions of a real satellite network. To quantitatively analyze the impact of user scale on the performance of the collaborative distribution mechanism, this simulation experiment sets up five different user scale scenarios, and executes 10 simulations for each scenario. 3 Multiple independent replicate experiments ensure that the experimental results have statistical validity, stability and reliability.

[0090] In this invention, network overhead refers to the ratio of the total number of symbols required to ensure all edge users complete decoding to the original number of symbols. A lower network overhead indicates less network resources are needed, thus indicating higher mechanism performance. Assuming decoding can be successful with only one spray operation, the network overhead of the cooperative mechanism is:

[0091] (1);

[0092] in, This represents the network overhead of the coordination mechanism. Indicates the number of symbols for the first sprayed block. Indicates the number of blocks in the first print file. Indicates the number of files to be repainted. Indicates the first Number of block-sprayed symbols, Indicates the code length.

[0093] In this experiment, the code length of the Raptor Q code is set to be... The length is 1024. Also 1024, the distributed file size is 100M, the quantile of the log-normal distribution. For three different logarithmic packet loss rate mean values ​​of 0.01, 0.05, and 0.1, the network overhead data of each mechanism were tested, and the corresponding experimental results are as follows: Figure 7 (a) Figure 7 (b) Figure 7 As shown in (c).

[0094] Analysis of network overhead simulation results under three different packet loss rates shows that:

[0095] As the user base expands, the overhead curve of the traditional HARQ mechanism exhibits a steep slope and a rapid upward trend; in contrast, the overhead growth of this invention is much more gradual, remaining at a low level throughout. This fully demonstrates that this invention can effectively reduce redundant data transmission, significantly reduce the occupation of satellite link bandwidth resources, and improve the overall transmission economy of the system.

[0096] A longitudinal comparison under different packet loss rates reveals that, as the mean logarithmic packet loss rate increases (i.e., channel conditions deteriorate), although the absolute network overhead of all methods increases, the performance advantage of this invention over the traditional HARQ mechanism becomes more prominent. Especially in extreme scenarios with high packet loss rates (mean 0.1%), traditional mechanisms often incur significant overhead to ensure reliability, while this invention still manages to keep the overhead within a low range. This demonstrates that this invention possesses stronger adaptability and robustness under poor link quality conditions, enabling it to suppress overhead expansion to the greatest extent while ensuring transmission reliability.

[0097] Based on the two embodiments above, it can be concluded that compared with the traditional satellite multicast HARQ mechanism based on average packet loss rate redundancy configuration and maximum packet loss rate redundancy configuration, the satellite-ground collaborative data distribution mechanism based on RaptorQ code proposed in this invention has a lower frequency of collaborative interaction, better network overhead control capability, and the overall collaborative transmission performance and resource utilization efficiency are significantly better than the existing traditional technical solutions.

[0098] Example 3: This example proposes a satellite-ground collaborative data distribution system based on RaptorQ codes. The system, applying the method of this invention, includes the following steps:

[0099] The satellite-ground collaborative data distribution building module is configured to perform the following process: distribute probe data via satellite link multicast and obtain the initial quality status of each edge satellite link;

[0100] The read module is configured to perform the following process: read the encoding parameters of the local RaptorQ code and calculate the encoding redundancy of the initial distribution based on the packet loss rate of each edge satellite link;

[0101] The data distribution module is configured to perform the following process: generate quota first spray symbols and excess first spray symbols according to the satellite-ground collaborative distribution strategy, and then distribute the data.

[0102] The data supplementation module is configured to perform the following process: receive supplementation requests and real-time link quality from each edge terminal, generate quota supplementation symbols and excess supplementation symbols according to the satellite-ground collaborative supplementation strategy, and perform data supplementation.

[0103] Example 4: This example proposes an electronic system, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the method steps of the present invention.

[0104] Example 5: This example proposes a computer-readable storage medium storing a computer program thereon. When the computer program is executed by a processor, it implements the steps of the method described in this invention, which will not be repeated here.

[0105] Example 6: This example proposes a computer program product, including a computer program / instructions. When the computer program / instructions are executed by a processor, they implement the steps of the method described in this invention, which will not be repeated here.

[0106] It should be noted that the processing flow of embodiments 3-6 corresponds to the specific steps of the method provided in embodiment 1 of the present invention, and has the corresponding functional modules and beneficial effects of the method. Technical details not described in detail in this embodiment can be found in the method provided in embodiment 1 of the present invention.

[0107] The program code used to implement the methods of this application may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing device, such that when executed by the processor or controller, the functions / operations specified in the flowcharts and / or block diagrams are implemented. The program code may be executed entirely on a machine, partially on a machine, as a standalone software package partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0108] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A satellite-ground collaborative data distribution method based on RaptorQ codes, characterized in that, Includes the following steps: Step S01: Construct a satellite-ground collaborative data distribution system to distribute probe data via satellite link multicast and obtain the initial quality status of satellite links at each edge end; Step S02: Read the encoding parameters of the local RaptorQ code and calculate the encoding redundancy of the first distribution based on the packet loss rate of each edge satellite link; Step S03: Generate the quota first spray symbol and the excess first spray symbol according to the satellite-ground collaborative distribution strategy, and distribute the data; Step S04: Receive supplementary spraying requests and real-time link quality from each edge terminal, generate quota supplementary spraying symbols and excess supplementary spraying symbols according to the satellite-ground collaborative supplementary spraying strategy, and perform data supplementary spraying.

2. The satellite-ground collaborative data distribution method based on RaptorQ codes according to claim 1, characterized in that, In step S01, the satellite-ground collaborative data distribution system includes a data center, a satellite link, a ground link, and an edge receiver. The satellite link is used for multicast communication, the ground link is used for unicast communication, and the edge receiver can simultaneously access the satellite link and the ground link through multi-link devices to realize satellite-ground collaborative networking. The probe data is used for initial link quality detection, which is then distributed to each edge terminal via satellite link multicast. Each edge terminal then feeds back the real-time satellite link quality status to the data center via ground link, serving as data support for subsequent calculation of coding redundancy and formulation of distribution strategies.

3. The satellite-ground collaborative data distribution method based on RaptorQ codes according to claim 2, characterized in that, In step S02, under the conditions that the Raptor Q code length K is 512 and the data packet length L is 1024, during the actual data distribution process, based on the specific packet loss situation of the link and the system's requirements for decoding success rate, the coding redundancy in the satellite-ground collaborative data distribution process is dynamically adjusted with reference to the relationship between packet loss rate, redundancy rate, and decoding success rate. : （1）； in, The packet loss rate corresponding to different coding redundancy rates, To improve decoding success rate, The dynamic redundancy tuning coefficient is obtained through offline simulation analysis and curve fitting of the relationship between packet loss rate, redundancy rate, and decoding success rate of RaptorQ codes, and is used to adjust coding redundancy.

4. The satellite-ground collaborative data distribution method based on RaptorQ codes according to claim 3, characterized in that, In step S02, the packet loss rate of each edge satellite link The probability density function expression for the packet loss rate of each edge satellite link, which follows a log-normal distribution, is as follows: （2）； in, The probability density function representing the packet loss rate of each edge satellite link. It is the mean of the logarithmic packet loss rate, i.e. = ; It is the standard deviation of the logarithmic packet loss rate, representing the range of fluctuation of the logarithmic packet loss rate; Based on the quantile characteristics of the log-normal distribution, the quantile method is used to determine reference values ​​for high packet loss rates, and above... Packet loss rate at quantiles satisfy: （3）； in, For terminal coverage ratio, The upper part of the standard normal distribution quantiles; Based on the quantile characteristics of the packet loss rate distribution, select The value at this point is used as a reference value for generating the quota first spray symbol, thus the expression for the coding redundancy of the quota first spray symbol is: （4）； in, This indicates redundancy in the quota coding; The maximum packet loss rate is selected as the reference value for generating the excess first spray symbol, and the coding redundancy r of the excess first spray symbol is obtained. od The expression is: （5）； in, This indicates excessive coding redundancy. This indicates the maximum packet loss rate in the link.

5. The satellite-ground collaborative data distribution method based on RaptorQ codes according to claim 4, characterized in that, In step S03, the satellite-ground collaborative distribution strategy divides the file to be distributed into blocks and generates a quota first spray symbol and an excess first spray symbol based on the RaptorQ code encoding rules. The quota first spray symbol is distributed to all edge terminals through the satellite multicast link, and the excess first spray symbol is transmitted to edge terminals with high packet loss rate through the ground unicast link. According to the encoding rules of RaptorQ code, the quota first spray symbol of the satellite-ground collaborative data distribution mechanism. sequence length for: （6）； in, Symbol for first spray of quota The sequence length, The code length of the Raptor Q code. For the corresponding extended code length; First spray mark of quota This data is distributed to all edge devices within the system via satellite link multicast, ensuring its availability within the system. At the edge, successful decoding was achieved during the initial distribution process; The super-first-spray symbol of the satellite-ground collaborative data distribution mechanism Maximum sequence length for: （7）； in, Symbol indicating excess first spray The maximum sequence length; Excess First Spray Symbol The packet loss rate of unicast transmission via ground link to the system At the edge, as a supplement to the initial spray symbol, it ensures that edge terminals with abnormal packet loss rates achieve complete decoding during the initial distribution process. The satellite-ground collaborative distribution strategy provides targeted data retransmission based on the packet loss rate of specific edge terminals, through at most... One extra first-spray symbol is reissued to achieve complete decoding of all edge ends; The number of symbols in a single block during the initial distribution process is: （8）； in, Indicates the number of symbols in a single block. Indicates the first The number of excess first spray symbols corresponding to each edge end.

6. The satellite-ground collaborative data distribution method based on RaptorQ codes according to claim 5, characterized in that, In step S04, the satellite-ground coordinated spraying strategy involves the data center generating a quota spraying symbol and an excess spraying symbol based on the spraying requests from each edge terminal. The quota spraying symbol is distributed to all edge terminals via a satellite multicast link, while the excess spraying symbol is transmitted to edge terminals with high packet loss rates via a ground unicast link. After a round of data distribution is completed, the data center monitors the packet replenishment requests from the edge devices in real time, organizes the replenishment request sequences from each edge device by block, and counts the number of edge devices that need to replenish each file block. Based on the quantile characteristics of the log-normal distribution, determine and The size relationship, in the satellite-ground coordinated supplementary spray strategy, the packet number of the supplementary spray encoded data Use an incremental approach; 1) When = 0: This means that the data center has not received a packet replacement request frame for the current statistics file block, and there is no need to perform data patching operation on the current statistics file block; 2) When : Indicates the percentage of edges that need respraying out of the total number of edges. Within this scope, only the overspray symbol needs to be generated. And it is transmitted only to the designated edge terminal via ground communication links; Calculate the packet loss rate at the edge of the link that needs to be re-sprayed for each file block. The number of packets requiring additional spraying is calculated by selecting the packet loss rate with the highest value among them, resulting in the number of excess spraying symbols: （9）； in, Symbol indicating overspray The sequence length, This indicates the number of re-spray packages required for each file block; The satellite-ground collaborative supplementary data injection strategy provides targeted data supplementation based on the packet loss rate at specific edge devices, through up to... The transmission of each overspray symbol ensures the integrity of data at each edge and achieves complete decoding. 3) When : Indicates that the number of edges requiring repainting exceeds the total number of edges. Then, both satellite multicast and terrestrial unicast communication methods must be combined to complete the data replenishment work; Calculate the packet loss rate at the edge of the link that needs to be re-sprayed for each file block. And the number of packs that need respraying and to Sort the packet loss rates at each edge and select the 1st edge. The packet loss rate at each edge is used as the symbol for calculating the quota for refilling. Use the reference value to select the maximum packet loss rate. As a symbol for calculating excess spraying Reference value; remember = = Then, from equation (1), we get: （10）； （11）； in, Symbol for fixed-quota respray The sequence length, Indicates the first Packet loss rate at the edge; The satellite-ground coordinated supplementary spraying strategy is distributed via satellite multicast link. A fixed-quota respray symbol is used to achieve a lower packet loss rate. The edge can be successfully decoded in this round; through at most The additional spraying of one extra spray symbol enables complete decoding of all edge ends in this round; Therefore, the number of symbols per block during the respraying process is: 2 （12）； in, This indicates the number of symbols per block during the retouching process. This represents the number of excess spray symbols corresponding to the i-th edge.

7. A satellite-ground collaborative data distribution system based on RaptorQ codes, characterized in that, The system comprising the steps of applying the method according to any one of claims 1 to 6, wherein the system includes: The satellite-ground collaborative data distribution building module is configured to perform the following process: distribute probe data via satellite link multicast and obtain the initial quality status of each edge satellite link; The read module is configured to perform the following process: read the encoding parameters of the local RaptorQ code and calculate the encoding redundancy of the initial distribution based on the packet loss rate of each edge satellite link; The data distribution module is configured to perform the following process: generate quota first spray symbols and excess first spray symbols according to the satellite-ground collaborative distribution strategy, and then distribute the data. The data supplementation module is configured to perform the following process: receive supplementation requests and real-time link quality from each edge terminal, generate quota supplementation symbols and excess supplementation symbols according to the satellite-ground collaborative supplementation strategy, and perform data supplementation.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the computer program is executed, it implements the steps of the method as described in any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, The computer program is configured to implement the steps of the method according to any one of claims 1 to 6 when invoked by a processor.

10. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the steps of the method according to any one of claims 1 to 6.

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