Message transmission method, satellite device, storage medium and computer program product

Abstract

The invention discloses a message transmission method, satellite equipment, a storage medium and a computer program product. The method comprises the steps that a target message block combination is obtained, and the target message block combination is obtained by combining at least one type of multiple ship automatic identification system message blocks; performing frame structure layered assembly on the target message block combination to obtain a ship automatic identification system data frame; and carrying out data transmission on the ship automatic identification system data frame. According to the invention, the technical problems of low data transmission efficiency, poor frame structure adaptability and low coding fault-tolerant capability of a message transmission method provided in the related technology are solved.

Description

Technical Field

[0001] This invention relates to the field of data collection and application systems for satellite ship automatic identification systems, and more specifically, to a message transmission method, satellite equipment, storage medium, and computer program product. Background Technology

[0002] The Automatic Identification System (AIS) is a core navigation safety infrastructure required by the International Maritime Organization (IMO) for ships, providing crucial technical support for global maritime traffic dynamic monitoring. Traditional terrestrial AIS systems rely on Very High Frequency (VHF) communication links, limiting their coverage to near-shore areas within 100 kilometers of the shore, making them unsuitable for monitoring ocean-going navigation and distant sea areas. Among related technologies, satellite-based AIS (AIS-SAT) based on low-Earth orbit satellites effectively overcomes the coverage limitations of traditional terrestrial AIS, achieving global monitoring of ship dynamics and providing important technical support for maritime navigation safety, control of illegal maritime activities, and comprehensive management of marine resources. However, satellite AIS systems suffer from low data transmission efficiency, poor frame structure adaptability, and low coding error tolerance during message transmission, making it difficult to achieve stable, efficient, and error-free data exchange in complex space communication environments.

[0003] There is currently no effective solution to the above problems. Summary of the Invention

[0004] This invention provides a message transmission method, satellite equipment, storage medium, and computer program product to at least solve the technical problems of low data transmission efficiency, poor frame structure adaptability, and low coding fault tolerance in the message transmission methods provided in the related art.

[0005] According to one aspect of the present invention, a message transmission method is provided, comprising: acquiring a target message block combination, wherein the target message block combination is obtained by combining multiple Automatic Identification System (AIS) message blocks of at least one type; performing frame structure layering and assembly on the target message block combination to obtain an AIS data frame; and transmitting the AIS data frame.

[0006] Optionally, the multiple Automatic Identification System (AIS) message blocks of at least one type include: standard format AIS message blocks; long format AIS message blocks; and auxiliary status AIS message blocks.

[0007] Optionally, obtaining the target message block combination includes: obtaining an initial message block, wherein the initial message block is obtained by forward error correction coding when storing the initial payload data sent by the Automatic Identification System (AIS); and performing decoding and combination processing on the initial message block to obtain the target message block combination.

[0008] Optionally, performing layered frame structure assembly on the target message block combination to obtain the Automatic Identification System (AIS) data frame includes: assembling the target message block combination into an upper-layer data frame structure to obtain a first assembly result; assembling the first assembly result into a lower-layer transmission frame and coding structure to obtain a second assembly result; and generating the AIS data frame based on the second assembly result.

[0009] Optionally, assembling the target message block combination into an upper-layer data frame structure to obtain a first assembly result includes: setting a control header based on the target message block combination; and assembling the control header and the target message block combination into an upper-layer data frame structure to obtain the first assembly result.

[0010] Optionally, the control header may include at least the following fields: frame synchronization identifier field, version management field, length indicator field, satellite number field, block type field, block number field, timestamp field, and reserved field.

[0011] Optionally, assembling the first assembly result into a lower-level transmission frame and coding structure to obtain a second assembly result includes: setting the transmission frame master header, transmission frame data unit area, and transmission frame error control field based on the first assembly result; and assembling the transmission frame master header, transmission frame data unit area, and transmission frame error control field into a lower-level transmission frame and coding structure to obtain the second assembly result.

[0012] Optionally, the main header of the transmission frame includes at least the following fields: main channel identifier field, transmission frame version number field, virtual channel identifier field, virtual channel frame count field, signal field field, and frame header error control field.

[0013] Optionally, the transmission frame error control field is used to perform redundancy check encoding on the valid data composed of the transmission frame main header and the transmission frame data unit area, and to scramble the valid data.

[0014] Optionally, generating an Automatic Identification System (AIS) data frame based on the second assembly result includes: setting a synchronization header and a transmission frame body based on the second assembly result, wherein the synchronization header is used to assist the receiving end in synchronizing the AIS data frame, and the transmission frame body is used to carry the second assembly result; assembling the synchronization header and the transmission frame body to generate the AIS data frame.

[0015] According to another aspect of the present invention, a message transmission apparatus is also provided, comprising: an acquisition module for acquiring a target message block combination, wherein the target message block combination is obtained by combining multiple Automatic Identification System (AIS) message blocks of at least one type; a layered assembly module for performing frame structure layered assembly on the target message block combination to obtain an AIS data frame; and a transmission module for transmitting the AIS data frame.

[0016] Optionally, the multiple Automatic Identification System (AIS) message blocks of at least one type include: standard format AIS message blocks; long format AIS message blocks; and auxiliary status AIS message blocks.

[0017] Optionally, the acquisition module is further configured to: acquire an initial message block, wherein the initial message block is obtained by forward error correction coding when storing the initial payload data sent by the Automatic Identification System (AIS); and perform decoding and combination processing on the initial message block to obtain a target message block combination.

[0018] Optionally, the layered assembly module is further configured to: assemble the target message block combination into an upper-layer data frame structure to obtain a first assembly result; assemble the first assembly result into a lower-layer transmission frame and encoding structure to obtain a second assembly result; and generate a ship automatic identification system data frame based on the second assembly result.

[0019] Optionally, the layered assembly module is also used to: set a control header based on the target message block combination; and assemble the control header and the target message block combination into an upper-layer data frame structure to obtain a first assembly result.

[0020] Optionally, the control header may include at least the following fields: frame synchronization identifier field, version management field, length indicator field, satellite number field, block type field, block number field, timestamp field, and reserved field.

[0021] Optionally, the layered assembly module is further configured to: set the transmission frame master header, transmission frame data unit area and transmission frame error control field respectively based on the first assembly result; and assemble the transmission frame master header, transmission frame data unit area and transmission frame error control field into a lower-level transmission frame and coding structure to obtain a second assembly result.

[0022] Optionally, the main header of the transmission frame includes at least the following fields: main channel identifier field, transmission frame version number field, virtual channel identifier field, virtual channel frame count field, signal field field, and frame header error control field.

[0023] Optionally, the transmission frame error control field is used to perform redundancy check encoding on the valid data composed of the transmission frame main header and the transmission frame data unit area, and to scramble the valid data.

[0024] Optionally, the layered assembly module is also used to: set a synchronization header and a transmission frame body based on the second assembly result, wherein the synchronization header is used to assist the receiving end in synchronizing the Automatic Identification System (AIS) data frames, and the transmission frame body is used to carry the second assembly result; and assemble the synchronization header and the transmission frame body to generate an AIS data frame.

[0025] According to another aspect of the present invention, a satellite device is also provided, comprising: a memory storing an executable program; and a processor for running the program, wherein the program executes the message transmission method of the present invention during runtime.

[0026] According to another aspect of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored executable program, wherein, when the executable program is running, it controls the device where the storage medium is located to execute the message transmission method of the present invention.

[0027] According to another aspect of the present invention, a computer program product is also provided, including a computer program that, when executed by a processor, implements the message transmission method of the present invention.

[0028] According to another aspect of the present invention, a chip system is also provided, comprising: a processor for calling and running a computer program from a memory, such that a communication device equipped with the chip system performs the message transmission method of the present invention.

[0029] In this embodiment of the invention, by acquiring a target message block combination, and then performing frame structure layering and assembly on the target message block combination to obtain a ship automatic identification system data frame, and finally transmitting the ship automatic identification system data frame, the comprehensiveness and real-time performance of the satellite AIS system's information collection in global sea areas are improved. This achieves the technical effects of enhancing data transmission efficiency, flexibly adapting to various on-board environmental conditions, and improving coding fault tolerance, thereby solving the technical problems of low data transmission efficiency, poor frame structure adaptability, and low coding fault tolerance in the message transmission methods provided in related technologies. Attached Figure Description

[0030] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0031] Figure 1 This is a flowchart of a message transmission method according to one embodiment of the present invention;

[0032] Figure 2This is a schematic diagram of a first assembly result according to one embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of a data frame of an Automatic Identification System for Ships according to one embodiment of the present invention;

[0034] Figure 4 This is a structural block diagram of a message transmission device according to one embodiment of the present invention. Detailed Implementation

[0035] For ease of understanding, some concepts related to embodiments of the present invention are illustrated below for reference.

[0036] Automatic Identification System (AIS): A key component of an advanced maritime safety and vessel traffic management system, AIS utilizes digital communication technology to enable automatic information exchange between vessels and between vessels and shore-based facilities globally. AIS was designed to improve maritime traffic safety, increase navigation efficiency, and contribute to environmental protection and maritime search and rescue operations. Specifically, AIS operates based on VHF radio signals, broadcasting and receiving information through two different channels (AIS1 and AIS2). It automatically transmits information such as a vessel's position, speed, course, vessel identification (e.g., Maritime Mobile Service Identity (MMSI)), name, call sign, size, type, destination, and estimated time of arrival. This information is broadcast every few seconds, allowing nearby vessels or shore-based receiving stations to be aware of the real-time movement of vessels in the surrounding waters, thus preventing collisions and achieving safer and more efficient maritime navigation. Furthermore, AIS communication is bidirectional; it can not only send its own information but also receive broadcasts from other AIS-equipped vessels or shore stations.

[0037] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0038] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0039] AIS (Airborne Information System) is a core navigation safety infrastructure required by the IMO for ships, providing crucial technical support for global maritime traffic dynamic monitoring. Traditional terrestrial AIS systems rely on VHF communication links, with coverage limited to near-shore areas within 100 kilometers of the shore, making them unsuitable for monitoring the needs of ocean-going navigation and distant sea areas. Among related technologies, AIS-SAT effectively overcomes the coverage limitations of traditional terrestrial AIS, achieving global monitoring of ship dynamics and providing important technical support for maritime navigation safety, control of illegal maritime activities, and comprehensive management of marine resources. However, satellite AIS systems suffer from low data transmission efficiency, poor frame structure adaptability, and low coding error tolerance during message transmission, making it difficult to achieve stable, efficient, and error-free data exchange in complex space communication environments.

[0040] Specifically, firstly, because satellite AIS systems need to process a large number of ship signals from different directions and speeds, information conflicts and delays are prone to occur, leading to low data transmission efficiency. Secondly, the high-speed movement of satellites can cause Doppler shift, and coupled with interference from the Earth's atmosphere and the space radiation environment, this reduces signal quality and data transmission stability, making the existing AIS data frame structure difficult to adapt to the complex channel environment on satellite, thus reducing data transmission efficiency and reliability. Furthermore, the decrease in signal-to-noise ratio and increase in data error rate caused by long-distance communication between satellite and ground are insufficient to ensure the complete and lossless transmission of information under harsh conditions, thus limiting the stable operation and efficient data exchange of satellite AIS systems in complex space communication environments. In addition, the impact of the space radiation environment on electronic equipment also leads to a decrease in data transmission reliability.

[0041] According to embodiments of the present invention, a method embodiment for message transmission is provided. The method embodiment provided in this invention can be executed in a terminal device (the terminal device may include, but is not limited to, a satellite terminal, a mobile terminal), or a similar network device. Taking operation on a satellite device as an example, the satellite device may include one or more processors (processors may include, but are not limited to, processing devices such as microprocessors (MCUs) or field-programmable gate arrays (FPGAs),) a memory for storing data, and a transmission device for communication functions. Those skilled in the art will understand that the above structure is merely exemplary and does not limit the structure of the satellite device. For example, the satellite device may also include more or fewer components, or have different configurations.

[0042] The memory can be used to store computer programs, such as application software programs and modules, like the computer program corresponding to the message transmission method in this embodiment of the invention. The processor executes various functional applications and data processing by running the computer program stored in the memory, thus implementing the above-described method. The memory may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory may further include memory remotely located relative to the processor, and these remote memories can be connected to satellite equipment via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0043] Transmission equipment is used to receive or send data via satellite networks. Specific examples of these networks may include satellite communication services provided by satellite equipment communication providers, enabling global data transmission through satellite equipment deployed in Earth orbit. In one example, transmission equipment includes a radio frequency (RF) transceiver, an antenna, a signal processor, and a network interface controller (NIC). The RF transceiver is used for direct data communication with the satellite equipment, while the NIC connects to ground stations or other network equipment, enabling the satellite equipment to access the Internet or dedicated networks, achieving global data transmission and information sharing.

[0044] Figure 1 This is a flowchart of a message transmission method according to one embodiment of the present invention, such as... Figure 1 As shown, the method includes the following steps:

[0045] Step S11: Obtain the target message block combination, wherein the target message block combination is obtained by combining multiple Automatic Identification System (AIS) message blocks of at least one type;

[0046] The aforementioned target message block combination refers to a data unit composed of multiple AIS message blocks of at least one type combined according to specific rules and structures, used for the effective transmission and management of data in the satellite AIS system.

[0047] Specifically, the target message block combination aims to make full use of the limited onboard transmission resources and achieve unified processing and transmission of multiple types of AIS data through efficient message block organization and splicing. This will improve the efficiency and adaptability of data transmission, ensure the integrity and accuracy of AIS data in the satellite environment, and support global ship dynamic monitoring and marine resource management.

[0048] The aforementioned Automatic Identification System (AIS) message block refers to a data block encapsulated according to the AIS standard, carrying information such as the vessel's identity, position, heading, and speed. Specifically, the aforementioned AIS message block is the basic unit constituting the data transmission of the AIS system, capable of providing dynamic information about vessels at sea, either independently or in combination.

[0049] For example, a target message block combination can be constructed by combining multiple AIS message blocks of at least one type. The combination process must adhere to specific format and quantity rules to ensure that the assembled target message block combination conforms to satellite communication specifications and fully utilizes the bandwidth resources of the satellite channel. Specifically, multiple AIS message blocks of at least one type can be sequentially combined according to their preset single message block length and maximum combinable quantity to form a complete payload area, i.e., the target message block combination.

[0050] The aforementioned message block combination mechanism can not only adapt to the processing needs of various types of AIS information on the satellite, but also enhance the system's adaptability to the characteristics of wide coverage and long latency transmission of satellites by optimizing the organization of data blocks, thereby achieving more efficient and stable data transmission.

[0051] Step S12: Perform frame structure layering and assembly on the target message block combination to obtain the Automatic Identification System (AIS) data frame;

[0052] The aforementioned Automatic Identification System (AIS) data frame refers to a composite data structure designed to achieve efficient and reliable data transmission from satellite to ground station. In this embodiment of the invention, by assembling the target message block combination into a frame structure layer, the resulting AIS data frame can not only be effectively transmitted in complex space environments, but also flexibly combined according to different types of messages to adapt to the characteristics of satellite channels. This enables continuous and stable transmission of key information such as the ship's position, heading, and speed, thereby achieving effective monitoring of global sea areas.

[0053] Step S13: Transmit the data frame of the Automatic Identification System (AIS) for ships.

[0054] Based on the above steps S11 to S13, by acquiring the target message block combination, and then performing frame structure layering and assembly on the target message block combination, a ship automatic identification system data frame is obtained. Finally, the ship automatic identification system data frame is transmitted, which achieves the goal of improving the comprehensiveness and real-time performance of information collection by the satellite AIS system in global sea areas. This achieves the technical effects of enhancing data transmission efficiency, flexibly adapting to various on-board environmental conditions, and improving coding fault tolerance, thereby solving the technical problems of low data transmission efficiency, poor frame structure adaptability, and low coding fault tolerance in the message transmission methods provided in related technologies.

[0055] Optionally, at least one type of multiple Automatic Identification System (AIS) message blocks includes:

[0056] Standard format Automatic Identification System (AIS) message blocks;

[0057] Long format Automatic Identification System (AIS) message blocks;

[0058] Automatic Identification System (AIS) message block for auxiliary status types.

[0059] The aforementioned standard format of Automatic Identification System (AIS) message blocks refers to AIS message formats conforming to the standards of the International Telecommunication Union (ITU) and the IMO. Their primary purpose is to meet the needs of maritime navigation safety and ship information exchange. Specifically, standard AIS message blocks contain fixed fields such as ship identification code, location information, heading and speed, destination, and estimated time of arrival, which are crucial for maritime traffic management, collision warning, and search and rescue operations.

[0060] The aforementioned long-format Automatic Identification System (LAIS) message block is an extended message block format with increased information capacity. It is primarily used to transmit more detailed or extended information, such as a long description of the vessel, cargo type, and voyage plan. Compared to standard AIS message blocks, LAIS message blocks can carry more data, thus reducing the number of transmissions required due to large data volumes and improving data integrity and accuracy. This is of great significance for monitoring ocean voyages and complex maritime activities.

[0061] The aforementioned Auxiliary Status Message (ASM) block is a new type of message block used to supplement and enhance standard AIS messages. ASM blocks can transmit more detailed ship status information, environmental data, and additional monitoring information, such as ship status, weather conditions, and ocean current information. Through ASM blocks, not only can the real-time status of ships be comprehensively understood, but the marine environment can also be monitored, providing richer data support for maritime safety and resource management.

[0062] Optionally, in step S11, obtaining the target message block combination includes:

[0063] Step S111: Obtain the initial message block, wherein the initial message block is obtained by forward error correction coding when storing the initial payload data sent by the Automatic Identification System (AIS).

[0064] Step S112: Decode and combine the initial message block to obtain the target message block combination.

[0065] The aforementioned initial message block refers to the coded data block formed after forward error correction coding of the initial payload data received from AIS, in order to cope with potential data corruption or loss due to the complex satellite channel environment. Specifically, this process is usually performed on-board, where the received AIS information undergoes forward error correction coding to enhance the data's anti-interference and self-repair capabilities. The coded data is organized into a series of fixed-size message blocks, which are then further processed and combined for efficient transmission to the ground station via the satellite channel.

[0066] The aforementioned forward error correction coding techniques include, but are not limited to, Reed-Solomon (RS) coding or Low-Density Parity-Check (LDPC) coding. These techniques add redundant information before data transmission, allowing for the recovery of complete and error-free original data even if some data is lost or damaged during transmission. Specifically, RS coding is a non-binary linear block coding widely used to correct burst errors, such as in digital television, wireless communication, and optical disc storage. By adding extra check symbols to the original data, RS coding can detect and correct multi-bit errors, ensuring data integrity and accuracy, and is particularly suitable for handling burst noise and interference encountered in environments such as satellite communication. LDPC coding is a linear block coding technique based on a sparse parity-check matrix, widely used in various fields due to its powerful error control capabilities and high coding efficiency. LDPC encoding introduces a large amount of redundant information before data transmission and sets the redundant bits to be distributed in the parity check matrix at a very low density, which makes the decoding process less complex and can effectively resist random errors and deep fading channels. It is suitable for high-bandwidth, long-distance communication systems, such as satellite communication, and can significantly improve the reliability and robustness of data transmission.

[0067] For example, during satellite AIS data transmission, after the satellite equipment receives the initial payload data sent from AIS, it first performs forward error correction coding on the initial payload data to enhance the transmission reliability of the data in the harsh space environment, thereby obtaining the initial message block. Subsequently, the satellite equipment further decodes and combines the initial message block obtained after forward error correction coding, thereby reorganizing multiple independent initial message blocks into a complete target message block combination suitable for transmission in the on-board environment.

[0068] Based on the above steps S111 to S112, by obtaining the initial message block and then decoding and combining the initial message block to obtain the target message block combination, not only can the integrity and accuracy of the data be ensured, but also the transmission efficiency and stability of AIS data under the unique conditions of satellites can be improved.

[0069] Optionally, in step S12, the target message block combination is assembled into a frame structure layered assembly to obtain a ship automatic identification system data frame including:

[0070] Step S121: Assemble the target message block combination into an upper-layer data frame structure to obtain the first assembly result;

[0071] Step S122: Assemble the lower-layer transmission frame and coding structure from the first assembly result to obtain the second assembly result;

[0072] Step S123: Based on the second assembly result, generate a ship automatic identification system data frame.

[0073] Specifically, the upper-layer data frame structure assembly of the target message block combination is the process of organizing multiple AIS message blocks of at least one type collected into a complete data frame according to a specific format and rules. This process mainly includes two key steps: control header generation and message block combination.

[0074] For example, in this embodiment of the invention, standard AIS message blocks, LAIS message blocks, and ASM message blocks can be flexibly combined to form data frames adapted to the characteristics of satellite communication. Specifically, the standard AIS message blocks and LAIS message blocks are 32 bytes long, and the ASM message blocks are 64 bytes long. During data frame assembly, up to 26 standard AIS / LAIS message blocks or up to 13 ASM message blocks can be selected and combined as needed to construct an 832-byte payload area. This not only improves data transmission efficiency but also provides sufficient flexibility to meet different types of AIS information requirements. The above design enables the satellite AIS system to collect and transmit ship information more efficiently while maintaining data integrity and accuracy in complex onboard environments.

[0075] For example, standard AIS / LAIS or ASM message blocks can be selected and combined according to the type and size of the ship data to be transmitted, thereby forming a target message block combination.

[0076] Specifically, assembling the lower-level transmission frame and coding structure of the first assembly result means that after the initial construction of the upper-level data frame structure has been completed, it is further adapted to the actual transmission requirements of satellite communication, and necessary error control mechanisms are added to ensure reliable data transmission in the harsh space environment.

[0077] Based on steps S121 to S123 above, the target message block combination is assembled into an upper-layer data frame structure to obtain a first assembly result. Then, the first assembly result is assembled into a lower-layer transmission frame and encoding structure to obtain a second assembly result. Finally, based on the second assembly result, a ship automatic identification system data frame is generated, which can realize efficient and reliable transmission of ship information globally. Even in harsh space environments, it can ensure the integrity and accuracy of data, providing strong technical support for marine monitoring, maritime safety and resource management.

[0078] Optionally, in step S121, the target message block combination is assembled into an upper-layer data frame structure to obtain a first assembly result, including:

[0079] Step S1211: Set the control header based on the target message block combination;

[0080] Step S1212: Assemble the upper-layer data frame structure of the control header and target message block combination to obtain the first assembly result.

[0081] The aforementioned control header is a key component of the upper-layer data frame structure, and its core function is to provide data frame management and synchronization information. Specifically, the control header contains necessary control and status information, enabling the receiving end to perform functions such as frame boundary identification, version management, data length indication, satellite identifier confirmation, message block type and number management, and timestamp recording.

[0082] Specifically, when setting control headers based on target message block combinations, it should be ensured that each field of the control header correctly reflects the message block type, quantity, and related management information. The control header settings need to be based on the type of AIS message being transmitted (such as standard AIS message blocks, LAIS message blocks, or ASM message blocks) and the corresponding quantity of these message blocks, ensuring that information such as "block type" and "block number" in the control header fields matches the actual message blocks.

[0083] Specifically, assembling the control header and target message block into a higher-layer data frame structure refers to concatenating the control header and message block byte-by-byte to form a complete data frame. During the concatenation process, it is important to ensure that the control header is at the very beginning of the data frame so that the receiving end can identify the control header first, thereby enabling subsequent frame decoding and data processing.

[0084] Based on the above steps S1211 to S1212, a control header is set based on the target message block combination, and then the control header and the target message block combination are assembled into an upper-layer data frame structure to obtain the first assembly result. This can effectively organize and mark AIS message data, ensuring that the data maintains integrity and traceability during the transmission between the satellite and the ground station. At the same time, through the satellite number, block type and number management information in the control header, the accurate identification and classification of AIS data blocks from different sources and types can be achieved, thereby improving the efficiency and reliability of the overall on-board AIS data transmission.

[0085] Optionally, the control header includes at least the following fields: frame synchronization identifier field, version management field, length indicator field, satellite number field, block type field, block number field, timestamp field, and reserved field. For example, the specific field composition of the above control header is shown in Table 1:

[0086] Table 1

[0087]

[0088] Figure 2 This is a schematic diagram of a first assembly result according to one embodiment of the present invention, such as... Figure 2 As shown, message blocks 1 through N constitute the target message block combination. The control header includes the following fields: frame synchronization identifier, version management, length indicator, satellite number, block type, block number, timestamp, and reserved fields. Standard AIS / LAIS message blocks are 32 bytes, and ASM message blocks are 64 bytes.

[0089] Optionally, in step S122, the first assembly result is assembled with a lower-layer transmission frame and coding structure to obtain a second assembly result, including:

[0090] Step S1221: Based on the first assembly result, set the transmission frame master header, transmission frame data unit area and transmission frame error control field respectively;

[0091] Step S1222: Assemble the lower-level transmission frame and coding structure by combining the transmission frame master header, transmission frame data unit area and transmission frame error control field to obtain the second assembly result.

[0092] The aforementioned transport frame header refers to the header information of a transport frame, containing critical control data that ensures the transport frame can be correctly identified and processed. Specifically, the transport frame header typically includes, but is not limited to, the transport frame's identifier, version information, source address, destination address, transport protocol type, data length, time, and sequence markers. In satellite AIS systems, the transport frame header may also include satellite- or AIS application-specific fields, such as virtual channel identifiers and synchronization sequences, to achieve frame synchronization, identification, and error control functions.

[0093] Specifically, the transmission frame master header is set based on the first assembly result, that is, the parameters in the transmission frame master header are determined according to the content of the upper-layer data frame (combination of control header and target message block). The above parameter settings should reflect and adapt to the characteristics and transmission requirements of the upper-layer data, thereby ensuring that the data can be correctly transmitted and received in the satellite AIS system.

[0094] The aforementioned transmission frame data unit area refers to the actual data area carrying the upper-layer data frame. In a satellite AIS system, the transmission frame data unit area is the main body of the transmission frame, responsible for encapsulating and carrying the AIS data received and processed from the satellite. This AIS data includes, but is not limited to, key data such as the ship's position, speed, heading, ship type, and ship identification number, as well as other possible additional information, such as the ship's dynamic operational status and navigation plan.

[0095] Specifically, the data unit area of ​​the transmission frame carries processed AIS information, which is composed of a control header and a target message block. The control header contains important control information such as frame synchronization and version management, while the target message block combination supports flexible combination of multiple types of message blocks such as AIS, LAIS, and ASM.

[0096] The aforementioned transmission frame error control field typically contains additional data required for error detection and correction, such as check bits generated by Cyclic Redundancy Check (CRC) or forward error correction coding (RS coding or LDPC coding). The presence of the transmission frame error control field can effectively reduce bit errors caused by channel interference and noise, ensuring high data transmission quality even under harsh conditions.

[0097] Based on steps S1221 to S1222 above, the transmission frame master header, transmission frame data unit area, and transmission frame error control field are set according to the first assembly result. Then, the transmission frame master header, transmission frame data unit area, and transmission frame error control field are assembled into a lower-level transmission frame and coding structure to obtain the second assembly result. This can enhance the reliability and efficiency of data transmission. Through optimized coding mechanism and structural design, data can better resist channel interference and reduce data loss when transmitted between satellite and ground station. At the same time, it can improve data processing speed and ensure the accurate and timely transmission of AIS messages worldwide.

[0098] Optionally, the main header of the transmission frame includes at least the following fields: main channel identifier field, transmission frame version number field, virtual channel identifier field, virtual channel frame count field, signal field field, and frame header error control field.

[0099] The aforementioned primary channel identifier field identifies the primary channel used by the transmission frame, i.e., the specific physical channel or frequency resource for data transmission between the satellite and the ground station. In inter-satellite communication and multi-satellite network environments, different services may be allocated to different frequencies or channels. The primary channel identifier field ensures that the receiver correctly associates data with the expected receiving channel or service type, avoiding data confusion and misunderstanding. The primary channel identifier field is particularly crucial when handling complex communication scenarios with multiple channels or frequency hopping, enabling the message transmission system to adapt to diverse communication configurations, thereby improving the system's flexibility and robustness.

[0100] The aforementioned transmission frame version number field records the format version of the transmission frame. As technology advances, the structure of data frames may change; for example, new fields may be introduced or the length and encoding of existing fields may be altered to improve transmission efficiency or enhance security. The existence of the version number field allows the receiving end to identify and understand the format of a specific frame, ensuring correct data parsing even if the frame structure changes, thus avoiding data loss or misreading due to format incompatibility. Furthermore, the transmission frame version number field assists system maintenance personnel in tracking and debugging potential problems, ensuring a smooth transition between different versions and maintaining continuous service quality.

[0101] The Virtual Channel Identifier (VCID) field is used to distinguish multiple logical data streams on the same physical channel. In satellite communication systems, especially when multiple satellites share the same frequency band or when a single satellite needs to process multiple types of data simultaneously, the VCID field can assign a unique identifier to different data streams. Based on the VCID field, ground receiving stations can route received data packets to the correct application or user and perform appropriate processing, thereby improving the accuracy and efficiency of data transmission and ensuring that even in complex multiplexing environments, various types of data can still be accurately delivered to their destination.

[0102] The aforementioned virtual channel frame count field records the number of data frames transmitted through a specific virtual channel since the last reset. This field is crucial for flow control and data integrity checks. In satellite communications, due to signal delays and multipath effects, data frames may arrive out of order or be lost. Using the virtual channel frame count field allows the receiver to verify the continuity of the data sequence, detect and correct any potential interruptions or duplications, thereby ensuring the integrity and order of data transmission.

[0103] The aforementioned signal field contains key signal characteristic information for receiver synchronization and demodulation, such as preambles and frame synchronization sequences. In the weak signal and adverse conditions of satellite communication, quickly and accurately capturing signal boundaries is a prerequisite for correct data transmission. The specific sequence design of the signal field helps the receiver quickly pinpoint the start and end positions of the transmitted frame. Even in the face of severe signal-to-noise ratio degradation, Doppler shift, or frequency-selective fading, it ensures correct identification and demodulation of data frames, thereby improving the robustness and speed of data transmission.

[0104] The aforementioned frame header error control field typically uses redundancy check or other error detection algorithms to calculate a checksum, which is then appended to the end of the frame header. This checksum is recalculated at the receiving end and compared with the received checksum. If the two do not match, it indicates that the data may have been corrupted or interfered with during transmission. Through this mechanism, the receiving end can quickly identify erroneous frame headers and take measures, such as requesting retransmission or discarding erroneous frames, thereby preventing subsequent errors in the data processing flow and ensuring the integrity and correctness of data frames received from the satellite.

[0105] Optionally, the transmission frame error control field is used to perform redundancy check encoding on the valid data composed of the transmission frame main header and the transmission frame data unit area, and to scramble the valid data.

[0106] The above valid data consists of the transmission frame header and the transmission frame data unit area, totaling 11640 bits.

[0107] For example, LDPC encoding can be performed on the effective data consisting of the transmit frame header and the transmit frame data unit area to generate 13168 bits of encoded data. Specifically, LDPC encoding adds extra redundant bits (check bits) to the effective data to form 13168 bits of encoded data. This addition of redundant bits is not a simple copy or direct association, but is generated based on a complex algorithm using a sparse parity-check matrix. This allows the receiver to recover the original data using the redundant bits even if a certain amount of errors or data loss occur in the received signal, thereby reducing the bit error rate. Furthermore, LDPC encoding can be combined with iterative decoding algorithms to further improve decoding performance. Iterative decoding algorithms can analyze and process the received data multiple times, gradually correcting potential errors until a predetermined decoding threshold is reached or it is determined that the data has been corrected as much as possible.

[0108] For example, scrambling the valid data can further enhance the effect of LDPC coding. Scrambling the valid data can break the potential regularity in the valid data, destroy long consecutive 0 / 1 sequences, reduce the impact of channel interference on consecutive bits, make the redundancy check of LDPC coding more evenly distributed, and improve the robustness of decoding and channel adaptability.

[0109] Based on the above optional embodiments, performing redundancy check coding on the effective data composed of the transmission frame main header and the transmission frame data unit area, and scrambling the effective data, can improve the transmission reliability of data in complex channel environments, reduce the bit error rate caused by space-specific environments (such as high radiation, multipath fading, rain attenuation, etc.), and at the same time, by scrambling the data to destroy long consecutive 0 / 1 sequences that may exist in the data, the adaptability of the channel and coding efficiency are further improved, ensuring the integrity and accuracy of data in the interplanetary transmission process of the satellite AIS system, optimizing the performance of data transmission and improving the robustness of the system.

[0110] Optionally, in step S123, generating a ship automatic identification system data frame based on the second assembly result includes:

[0111] Step S1231: Based on the second assembly result, set a synchronization header and a transmission frame body, wherein the synchronization header is used to assist the receiving end in synchronizing the data frames of the Automatic Identification System for ships, and the transmission frame body is used to carry the second assembly result.

[0112] Step S1232: Assemble the synchronization header and the main body of the transmission frame to generate a ship automatic identification system data frame.

[0113] The aforementioned synchronization header is a crucial part of the Automatic Identification System (AIS) data frame, used to assist the receiver in frame synchronization. After completing the second assembly, i.e., after redundancy check coding and scrambling of the AIS message block, a synchronization header can be designed and inserted at the very beginning of the transmission frame body. Specifically, the synchronization header may include a specific, predefined bit sequence that is easily identifiable at the receiver, used to determine the start position of the data frame, thereby achieving frame synchronization. The design of the synchronization header needs to consider Doppler shift, channel noise, and interference in satellite communication environments, ensuring that even under adverse communication conditions, the receiver can accurately identify the synchronization header and correctly parse the subsequent transmission frame body.

[0114] Figure 3 This is a schematic diagram of a data frame of an Automatic Identification System (AIS) for ships according to one embodiment of the present invention, as shown below. Figure 3 As shown, B1-B4 are the synchronization header, and B5-B1024 are the transmission frame body. The transmission frame body is obtained by performing redundancy check coding and scrambling on the second assembly result. Specifically, the second assembly result includes the transmission frame lead header, the transmission frame data unit area, and the transmission frame error control field. The transmission frame lead header includes the following fields: main channel identifier field, transmission frame version number field, spacecraft identifier field, virtual channel identifier field, virtual channel frame count field, signal field field, playback flag field, reserved field, and frame lead error control field. The transmission frame data unit area consists of a control header and a target message block combination composed of message block 1 to message block N.

[0115] Based on steps S1231 to S1232 above, a synchronization header and a transmission frame body are set based on the second assembly result. Then, the synchronization header and transmission frame body are assembled to generate a ship automatic identification system (AIS) data frame. This not only enables flexible processing of multiple types of AIS message blocks but also employs LDPC encoding and scrambling techniques to enhance data fault tolerance, reduce the bit error rate, and ensure stable operation under harsh space conditions such as high radiation and temperature fluctuations. Furthermore, the designed synchronization header helps the receiver perform frame synchronization quickly and accurately, while the transmission frame body effectively carries the encoded and scrambled AIS data, improving the integrity and accuracy of the information.

[0116] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0117] This invention also provides a message transmission device for implementing the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0118] Figure 4 This is a structural block diagram of a message transmission device according to one embodiment of the present invention, such as... Figure 4 As shown, the device includes:

[0119] The acquisition module 401 is used to acquire a target message block combination, wherein the target message block combination is obtained by combining multiple Automatic Identification System (AIS) message blocks of at least one type;

[0120] The hierarchical assembly module 402 is used to perform frame structure hierarchical assembly of the target message block combination to obtain the ship automatic identification system data frame;

[0121] The transmission module 403 is used to transmit data frames from the Automatic Identification System (AIS).

[0122] Optionally, the multiple Automatic Identification System (AIS) message blocks of at least one type include: standard format AIS message blocks; long format AIS message blocks; and auxiliary status AIS message blocks.

[0123] Optionally, the acquisition module 401 is further configured to: acquire an initial message block, wherein the initial message block is obtained by forward error correction coding when storing the initial payload data sent by the Automatic Identification System (AIS); and perform decoding and combination processing on the initial message block to obtain a target message block combination.

[0124] Optionally, the layered assembly module 402 is further configured to: assemble the target message block combination into an upper-layer data frame structure to obtain a first assembly result; assemble the first assembly result into a lower-layer transmission frame and encoding structure to obtain a second assembly result; and generate a ship automatic identification system data frame based on the second assembly result.

[0125] Optionally, the layered assembly module 402 is further configured to: set a control header based on the target message block combination; and assemble the control header and the target message block combination into an upper-layer data frame structure to obtain a first assembly result.

[0126] Optionally, the control header may include at least the following fields: frame synchronization identifier field, version management field, length indicator field, satellite number field, block type field, block number field, timestamp field, and reserved field.

[0127] Optionally, the layered assembly module 402 is further configured to: set the transmission frame master header, transmission frame data unit area and transmission frame error control field respectively based on the first assembly result; and assemble the transmission frame master header, transmission frame data unit area and transmission frame error control field into a lower-level transmission frame and coding structure to obtain a second assembly result.

[0128] Optionally, the main header of the transmission frame includes at least the following fields: main channel identifier field, transmission frame version number field, virtual channel identifier field, virtual channel frame count field, signal field field, and frame header error control field.

[0129] Optionally, the transmission frame error control field is used to perform redundancy check encoding on the valid data composed of the transmission frame main header and the transmission frame data unit area, and to scramble the valid data.

[0130] Optionally, the layered assembly module 402 is further configured to: set a synchronization header and a transmission frame body based on the second assembly result, wherein the synchronization header is used to assist the receiving end in synchronizing the Automatic Identification System (AIS) data frame, and the transmission frame body is used to carry the second assembly result; assemble the synchronization header and the transmission frame body to generate an AIS data frame.

[0131] It should be noted that the above modules can be implemented by software or hardware. For the latter, they can be implemented in the following ways, but are not limited to: all the above modules are located in the same processor; or, the above modules are located in different processors in any combination.

[0132] According to another aspect of the present invention, a satellite device is also provided, comprising: a memory storing an executable program; and a processor for running the program, wherein the program executes the message transmission method of the present invention during runtime.

[0133] Optionally, in this embodiment, the processor can be configured to perform the following steps via a computer program:

[0134] Step S11: Obtain the target message block combination, wherein the target message block combination is obtained by combining multiple Automatic Identification System (AIS) message blocks of at least one type;

[0135] Step S12: Perform frame structure layering and assembly on the target message block combination to obtain the Automatic Identification System (AIS) data frame;

[0136] Step S13: Transmit the data frame of the Automatic Identification System (AIS) for ships.

[0137] According to another aspect of the present invention, a computer-readable storage medium is also provided, the computer-readable storage medium including a stored executable program, wherein, when the executable program is running, it controls the device where the storage medium is located to execute the message transmission method of the present invention.

[0138] Optionally, in this embodiment, the storage medium may be configured to store a computer program for performing the following steps:

[0139] Step S11: Obtain the target message block combination, wherein the target message block combination is obtained by combining multiple Automatic Identification System (AIS) message blocks of at least one type;

[0140] Step S12: Perform frame structure layering and assembly on the target message block combination to obtain the Automatic Identification System (AIS) data frame;

[0141] Step S13: Transmit the data frame of the Automatic Identification System (AIS) for ships.

[0142] Optionally, in this embodiment, the storage medium may include, but is not limited to, various media capable of storing computer programs, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0143] According to another aspect of the present invention, a computer program product is also provided, including a computer program that, when executed by a processor, implements the message transmission method of the present invention.

[0144] Optionally, in this embodiment, the above-mentioned computer program product can be configured as a computer program that performs the following steps:

[0145] Step S11: Obtain the target message block combination, wherein the target message block combination is obtained by combining multiple Automatic Identification System (AIS) message blocks of at least one type;

[0146] Step S12: Perform frame structure layering and assembly on the target message block combination to obtain the Automatic Identification System (AIS) data frame;

[0147] Step S13: Transmit the data frame of the Automatic Identification System (AIS) for ships.

[0148] According to another aspect of the present invention, a chip system is also provided, comprising: a processor for calling and running a computer program from a memory, such that a communication device equipped with the chip system performs the message transmission method of the present invention.

[0149] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0150] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0151] In the several embodiments provided by this invention, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection can be through some interfaces; the indirect coupling or communication connection of units or modules can be electrical or other forms.

[0152] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0153] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0154] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0155] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A message transmission method, characterized in that, include: Obtain a target message block combination, wherein the target message block combination is obtained by combining multiple Automatic Identification System (AIS) message blocks of at least one type; The target message block combination is assembled into a frame structure layer to obtain the Automatic Identification System (AIS) data frame; Data frames from the Automatic Identification System (AIS) are transmitted.

2. The message transmission method according to claim 1, characterized in that, The at least one type of multiple Automatic Identification System (AIS) message blocks for ships includes: Standard format Automatic Identification System (AIS) message blocks; Long format Automatic Identification System (AIS) message blocks; Automatic Identification System (AIS) message block for auxiliary status types.

3. The message transmission method according to claim 1, characterized in that, Obtaining the target message block combination includes: Obtain the initial message block, wherein the initial message block is obtained by forward error correction coding when storing the initial payload data sent by the Automatic Identification System (AIS); The initial message block is decoded and combined to obtain the target message block combination.

4. The message transmission method according to claim 1, characterized in that, The target message block combination is assembled into a frame structure layered assembly to obtain the ship automatic identification system data frame, which includes: The target message block combination is assembled into an upper-layer data frame structure to obtain a first assembly result; The first assembly result is then assembled with a lower-layer transmission frame and coding structure to obtain a second assembly result. Based on the second assembly result, the Automatic Identification System (AIS) data frame is generated.

5. The message transmission method according to claim 4, characterized in that, The first assembly result obtained by assembling the target message block combination into an upper-layer data frame structure includes: Set the control header based on the target message block combination; The control header and the target message block are combined to perform upper-layer data frame structure assembly to obtain the first assembly result.

6. The message transmission method according to claim 5, characterized in that, The control header includes at least the following fields: frame synchronization identifier field, version management field, length indicator field, satellite number field, block type field, block number field, timestamp field, and reserved field.

7. The message transmission method according to claim 4, characterized in that, The second assembly result is obtained by assembling the first assembly result into a lower-layer transmission frame and coding structure, including: Based on the first assembly result, the transmission frame master header, the transmission frame data unit area, and the transmission frame error control field are respectively set; The transmission frame master header, the transmission frame data unit area, and the transmission frame error control field are assembled into a lower-level transmission frame and coding structure to obtain the second assembly result.

8. The message transmission method according to claim 7, characterized in that, The transmission frame header includes at least the following fields: main channel identifier field, transmission frame version number field, virtual channel identifier field, virtual channel frame count field, signal field field, and frame header error control field.

9. The message transmission method according to claim 7, characterized in that, The transmission frame error control field is used to perform redundancy check encoding on the valid data composed of the transmission frame main header and the transmission frame data unit area, and to scramble the valid data.

10. The message transmission method according to claim 4, characterized in that, Based on the second assembly result, generating the ship automatic identification system data frame includes: Based on the second assembly result, a synchronization header and a transmission frame body are set, wherein the synchronization header is used to assist the receiving end in synchronizing the data frames of the Automatic Identification System for ships, and the transmission frame body is used to carry the second assembly result; The synchronization header and the main body of the transmission frame are assembled to generate the Automatic Identification System (AIS) data frame.

11. A satellite device, characterized in that, include: Memory, which stores executable programs; A processor for running the program, wherein the program, when running, performs the message transmission method according to any one of claims 1 to 10.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored executable program, wherein, when the executable program is executed, it controls the device on which the storage medium is located to perform the message transmission method according to any one of claims 1 to 10.

13. A computer program product, characterized in that, It includes a computer program that, when executed by a processor, implements the message transmission method according to any one of claims 1 to 10.

14. A chip system, characterized in that, Includes: a processor for retrieving and running a computer program from memory, causing a communication device equipped with the chip system to perform the message transmission method as described in any one of claims 1 to 10.

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