Communication method and system based on Beidou short message

Abstract

The invention discloses a communication method and system based on a Beidou short message, and relates to the technical field of Beidou communication, and the method comprises the steps: a transmitting end obtains a to-be-communicated text, and encodes the to-be-communicated text based on the corresponding relation between 12 bits and Chinese characters, thereby obtaining an encoded byte code; the sending end performs subpackage processing on the byte code according to a preset communication protocol to generate a plurality of communication packets; the sending end sends the plurality of communication packets to a receiving end in sequence through a Beidou short message; a receiving end receives a plurality of communication packets, and obtains a complete coding byte code based on the preset communication protocol; and based on the corresponding relationship between 12 bits and Chinese characters, the receiving end decodes the complete coding byte code to obtain a to-be-communicated text. On the basis of the traditional coding format, the corresponding relation between the byte codes and the common Chinese characters is extracted, and the Chinese characters are compressed and expressed by 12-bit coding, so that more Chinese characters can be transmitted under the same byte number, and the single-time transmission efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of BeiDou communication technology, specifically a communication method and system based on BeiDou short message service. Background Technology

[0002] When conventional communication methods are unavailable, BeiDou short message service is often used as a last resort due to its wide coverage and lack of terrestrial network requirements. Currently, it is widely used in civilian, rescue, and firefighting fields. Although BeiDou communication can send packets once per second under extreme conditions, it is more common for ordinary users to send only one short message per minute, and each message can only send 120 bytes. Existing Chinese character encoding schemes (such as GB2312 and UTF-16) occupy 2 bytes (16 bits) per Chinese character, resulting in low transmission efficiency in the BeiDou short message environment, which makes it difficult to meet the needs of long text and continuous transmission of multiple packets.

[0003] Based on this, a communication method and system based on BeiDou short message service is provided, which can eliminate the drawbacks of existing technical solutions. Summary of the Invention

[0004] The purpose of this invention is to provide a communication method and system based on BeiDou short message service to solve the problem in the background technology that it is difficult to meet the requirements of long text and multi-packet continuous transmission.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A communication method based on BeiDou short message service specifically includes the following steps: Step S1: The sending end obtains the text to be communicated, and encodes the text to be communicated based on the correspondence between 12 bits and Chinese characters to obtain the encoded bytecode. Step S2: The sending end processes the bytecode into packets according to a preset communication protocol to generate multiple communication packets; Step S3: The sending end sends multiple communication packets to the receiving end sequentially via BeiDou short message service; Step S4: The receiving end receives multiple communication packets, performs judgment and reassembly operations based on the preset communication protocol, and obtains complete encoded bytecode; Step S5: The receiving end decodes the complete encoded bytecode based on the correspondence between the 12 bits and Chinese characters to obtain the text to be communicated.

[0006] Furthermore, the method for establishing the correspondence between the 12 bits and Chinese characters in step S1 is as follows: based on 3500 commonly used Chinese characters in the Chinese character list, a unique 12-bit code is assigned to each Chinese character according to the order of the characters in the Chinese character list. The value range of the 12-bit code corresponds to... A number.

[0007] Furthermore, the 12-bit encoding is also used to represent common punctuation marks and English letters, and the encoding of common punctuation marks and English letters occupies the remaining 596 numerical bits.

[0008] Furthermore, the preset communication protocol in step S2 includes a frame header, data length, sequence number identifier, total identifier, data content, and frame tail.

[0009] Furthermore, the frame header is 2 bytes long, fixed at two 255s, used to identify the start of a new communication packet; The data length is 2 bytes, representing the total number of bytes for the sequence number identifier and the data content; The sequence number identifier is 2 bytes long and represents the sequence number order of the current communication packet in the overall communication packet; The total identifier is 2 bytes long and represents the total number of times the entire communication packet needs to be sent. The data content is 108 bytes long and is represented as bytecode containing communication content; The frame tail is 4 bytes long and is used as a checksum.

[0010] Furthermore, the frame tail is generated based on the CRC check algorithm to confirm that all bytecode of the frame header, data length, sequence number identifier, total identifier, and data content are communicating normally. If the check is normal, the sending end treats the data byte to be sent as a binary number and performs a division operation on it using a preset polynomial. The remainder, i.e. the CRC check code, is appended to the data tail and sent together. If the check is abnormal, the receiving end initiates a retransmission request for the current communication packet.

[0011] Furthermore, the specific method by which the sending end performs packet processing of the bytecode according to the preset communication protocol in step S2 is as follows: Calculate the total length of the encoded bytecode; Based on the maximum length of 108 bytes of data content in each communication packet, the total bytecode is divided into several data segments, with the last data segment having a length of no more than 108 bytes. Each data segment is assigned a corresponding sequence number and a unified total identifier. Combined with the frame header, data length, and frame trailer, a complete communication packet is constructed.

[0012] Furthermore, the number of encoded bytes for each Chinese character, common punctuation mark, and English letter in the text to be communicated is 1.5 bytes.

[0013] A communication system based on BeiDou short message service, applied to a communication method based on BeiDou short message service, includes a sending end and a receiving end, both of which are connected to the BeiDou satellite network for communication. The sending end includes a text acquisition module, an encoding module, a packet sub-module, and a sending module; The text acquisition module is used to acquire the text to be communicated; The encoding module is used to encode the text to be communicated based on the correspondence between 12 bits and Chinese characters, so as to obtain the encoded bytecode. The packet sub-module is used to sub-package the bytecode according to a preset communication protocol to generate multiple communication packets; The sending module is used to send multiple communication packets sequentially to the receiving end via BeiDou short message service; The receiving end includes a receiving module, a verification and reconstruction module, and a decoding module; The receiving module is used to receive multiple communication packets sent by the sending end; The verification and reassembly module is used to verify and reassemble multiple communication packets based on the preset communication protocol to obtain complete encoded bytecode. The decoding module is used to decode the complete encoded bytecode based on the correspondence between the 12 bits and Chinese characters to obtain the text to be communicated.

[0014] Furthermore, the verification and reassembly module is also used to initiate a retransmission signal for the corresponding communication packet to the sending end when the verification finds that the communication packet is incomplete, and to perform sequential verification on the received multiple communication packets based on the sequence number identifier and the total identifier to ensure that the reassembly yields complete encoded bytecode.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: Based on traditional encoding formats, this invention extracts the correspondence between bytecode and commonly used Chinese characters, and uses 12-bit encoding to compress Chinese character representation, enabling the transmission of more Chinese characters with the same number of bytes, improving the efficiency of single transmission. Furthermore, this invention supports multi-packet continuous transmission and sequential reassembly, which can break through the BeiDou short message length limit and improve transmission reliability. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the method steps of the present invention.

[0017] Figure 2 This is a diagram showing the comparison of bit positions using different methods.

[0018] Figure 3 This is a schematic diagram of the system structure of the present invention.

[0019] Figure 4This is a schematic diagram of the structure of the transmitting end and the receiving end of the present invention.

[0020] Figure 5 This is a schematic diagram of an example structure of the present invention.

[0021] Figure label annotations: Sender 10, Text acquisition module 11, Encoding module 12, Packet sub-module 13, Sending module 14, Receiver 20, Receiver module 21, Verification and reconstruction module 22, Decoding module 23. Detailed Implementation

[0022] 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.

[0023] Example 1 In this embodiment, as Figure 1 and Figure 2 As shown, a communication method based on BeiDou short message service specifically includes the following steps: Step S1: The sending end 10 obtains the text to be communicated, and encodes the text to be communicated based on the correspondence between 12 bits and Chinese characters to obtain the encoded bytecode. Step S2: The sending end 10 processes the bytecode into packets according to the preset communication protocol to generate multiple communication packets; Step S3: The sending end 10 sends multiple communication packets to the receiving end sequentially via BeiDou short message service; Step S4: The receiving end receives multiple communication packets, performs judgment and reassembly operations based on the preset communication protocol, and obtains complete encoded bytecode; Step S5: The receiving end decodes the complete encoded bytecode based on the correspondence between 12 bits and Chinese characters to obtain the text to be communicated. In this embodiment, the encoding method increases the amount of information contained in 120 bytes of a single communication to a certain extent. Furthermore, a communication protocol is proposed that increases the amount of data in a single communication while adding the sequence number of the preceding and following communication content. This can break through the limitations of the existing BeiDou short message service and complete long text communication based on BeiDou short message service.

[0024] Specifically, the method for establishing the correspondence between the 12 bits and Chinese characters in step S1 is as follows: based on the 3500 commonly used Chinese characters in the list of commonly used Chinese characters, a unique 12-bit code is assigned to each Chinese character according to the order of the characters in the list. The value range of the 12-bit code corresponds to... The 12-bit encoding is also used to represent common punctuation marks and English letters. The encoding of common punctuation marks and English letters occupies the remaining 596 bits. For example, the comma "," is encoded as 111100001010. 596 is the difference between 4096 and 3500, indicating that this encoding method is sufficient for daily communication. For unencoded characters, escape encoding or reserved extension bits can be used.

[0025] Based on the "List of Commonly Used Characters in Modern Chinese", this invention assigns a unique 12-bit code to 3,500 commonly used Chinese characters. Combined with punctuation and English letter extensions, each character only requires 1.5 bytes to represent. Compared with the traditional UTF-16 encoding (2 bytes per Chinese character), more content can be transmitted under the same byte limit.

[0026] Specifically, the preset communication protocol in step S2 includes a frame header, data length, sequence number identifier, total identifier, data content, and frame trailer; The frame header is 2 bytes long, fixed as two 255s (0xFF 0xFF), used to identify the start of a new communication packet; The data length is 2 bytes, representing the total number of bytes for the sequence number identifier and the data content; The sequence number identifier is 2 bytes long and represents the sequence number order of the current communication packet within the overall communication packet sequence. The total identifier is 2 bytes long and represents the total number of times the entire communication packet needs to be sent; The data content is 108 bytes long and is represented as bytecode containing the communication content; The frame trailer is 4 bytes long and is used for checksums. The frame tail is generated based on the CRC check algorithm. It is used to confirm that all bytecode of the frame header, data length, sequence number identifier, total identifier, and data content are communicating normally. If the check is normal, the sending end 10 treats the data byte to be sent as a binary number and performs a division operation on it using a preset polynomial. The remainder, which is the CRC check code, is appended to the data tail and sent together. If the check is abnormal, the receiving end initiates a retransmission request for the current communication packet. The CRC check adopts the CRC-32 standard, the polynomial is 0x04C11DB7, the initial value is 0xFFFFFFFF, and the check code length is 4 bytes. It is appended to the data tail. The integrity of each communication packet is verified through CRC check, and a retransmission request is triggered when the check fails, thereby improving the transmission reliability in unreliable channels.

[0027] Specifically, in step S2, the sending end 10 processes the bytecode into packets according to the preset communication protocol in the following manner: Calculate the total length of the encoded bytecode; The total byte code is split into several data segments according to the maximum length of 108 bytes of the data content in each communication packet, and the length of the last data segment is not greater than 108 bytes; Allocate corresponding serial number identifiers and a unified total identifier for each data segment, and combine the frame header, data length, and frame tail to construct a complete communication packet.

[0028] Specifically, the encoded byte count corresponding to each Chinese character, common punctuation mark, and English letter in the communication text is 1.5 bytes.

[0029] Specifically, traditional encoding methods such as those based on the UTF16 encoding format, where each Chinese character occupies 2 bytes and 16 bits. If the output string is "今天天气真好" (Today's weather is great), and 6 Chinese characters occupy 96 bits, then the bit output is as follows: 01001110 11001010 Jin 01011001 00101001 Tian 01011001 00101001 Tian 01101100 00010100 Qi 01110111 00011111 Hen 01011001 01111101 Hao However, according to research and investigations, there aren't many commonly used Chinese characters in actual applications. In the "Table of Commonly Used Chinese Characters in Modern Chinese", there are a total of 3,500 Chinese characters that are commonly used by Chinese people and basically meet the needs of daily life. And 2^12 = 4,096, 4,096 > 3,500. Therefore, based on 12 bits (2 to the power of 12, corresponding to 12 bits) and the "Table of Commonly Used Chinese Characters in Modern Chinese", a unique Chinese character can be located; For example, when the output string is "今天天气真好" (Today's weather is great), looking up the table for each of the 6 Chinese characters respectively, the following is a schematic table of the digital order and the 12 - bit representation order, as shown in Table 1 below. A total of 12×6 = 72 bits are used. Compared with the existing 96 bits, this method can increase the communication content per byte code and thus improve the overall transmission efficiency; If the length is also 12 byte codes (96 bits), using this method, 8 Chinese characters can be transmitted, and the output is the string "今天天气真的很好" (Today's weather is really great). As shown in Table 2 below, a total of 12×8 = 96 bits are used. A comparison diagram of the bits of the two methods is as Figure 2 shown, increasing the communication efficiency by 33%. Similarly, it can be known that for the same 6 Chinese characters, the traditional technical solution requires 12 byte codes, while this invention only requires 9 byte codes, saving 1 / 4 of the communication unit.

[0030] Table 1 - Schematic Table of the Order of 6 Chinese Characters ; Table 2-8: Order of Chinese Characters ; Example 2 The difference from Example 1 is that, as in Example 2, ... Figures 3-5 As shown, the present invention provides a communication system based on BeiDou short message service, which is applied to a communication method based on BeiDou short message service. It includes a transmitter 10 and a receiver, both of which are connected to the BeiDou satellite network for communication. The sending end 10 includes a text acquisition module 11, an encoding module 12, a packet sub-module 13, and a sending module 14; Text acquisition module 11 is used to acquire the text to be communicated; The encoding module 12 is used to encode the text to be communicated based on the correspondence between 12 bits and Chinese characters, so as to obtain the encoded bytecode; The sub-packet module 13 is used to sub-packetize bytecode according to a preset communication protocol to generate multiple communication packets; The sending module 14 is used to send multiple communication packets sequentially to the receiving end via BeiDou short message service; The receiving end 20 includes a receiving module 21, a verification and reconstruction module 22, and a decoding module 23; The receiving module 21 is used to receive multiple communication packets sent by the sending end 10; The verification and reassembly module 22 is used to verify and reassemble multiple communication packets based on a preset communication protocol to obtain complete encoded bytecode. The decoding module 23 is used to decode the complete encoded bytecode based on the correspondence between 12 bits and Chinese characters to obtain the text to be communicated; In this embodiment, the sending end 10 encodes based on the "List of Commonly Used Characters in Modern Chinese" and the receiving end 20 decodes based on the "List of Commonly Used Characters in Modern Chinese" to complete the communication.

[0031] Specifically, the verification and reassembly module 22 is also used to initiate a retransmission signal for the corresponding communication packet to the sending end 10 when the verification finds that the communication packet is incomplete, and to perform sequential verification on the received multiple communication packets based on the sequence number identifier and the total identifier to ensure that the reassembly yields complete encoded bytecode.

[0032] Specifically, the following example shows the sending of a text containing a total of 212 Chinese characters and punctuation marks. Based on the current preset communication protocol, the current method only requires 1.5 bytes to represent one Chinese character. For a text with a total of 212 characters, 318 bytes can be used. 318 bytes represent two complete communication packets plus one incomplete communication packet, represented as 108 + 108 + 102 = 318. Let the sending end 10 be client A and the receiving end 20 be client B. Figure 5As shown, the communication steps specifically include: Step S1: Client A reads the text content of the text to be communicated and encodes the text to be communicated based on the above encoding method to obtain the encoded bytecode. The total number of bytecode is 318. Step S2: Based on the preset communication protocol, the bytecode is split into packets. Client A splits the 318 bytes into two 108-byte data contents and one 102-byte data contents. Based on the above three data contents, three communication packets of 120 bytes each are constructed respectively: Each communication packet's frame header consists of 2 bytes, fixed as two 255s; The data length is 2 bytes, and the contents are 108, 108, and 102 respectively; The sequence number is identified by two bytes, with contents of 1, 2, and 3 respectively; The total identifier is 2 bytes, and the content is 3; The data content consists of 108 bytes, including the encoded bytecode; The frame tail consists of 4 bytes, which are generated based on the frame header, data length, sequence number identifier, total identifier, and data content. The check content is generated based on CRC encoding. If the data content of the three communications is different, the generated frame tail will be different. Step S3: Client A sends the above three communication packets to Client B in three separate BeiDou short message communications. Step S4: Client B receives three communication packets sent by Client A in three separate transactions. Based on the preset communication protocol, it performs judgment and reassembly operations, and based on the sequence number identifier and total identifier, it reads the three communication packets continuously, assembles the complete communication content, and obtains the complete encoded bytecode. Client B receives communication packets: The frame header is used to determine whether the current data is valid, and then the data length is read. The data lengths are 108, 108, and 102, and then the remaining 108, 108, and 102 bytes are read. Read the sequence number identifier and the total identifier to determine the total number of communication packets and the sequence number of the current communication packet in all communication packets; Read the data content and decode it based on the above encoding method, namely the correspondence between 12 bits and Chinese characters; Read the frame tail data to determine if the local communication content is complete. If it is incomplete, client B initiates a retransmission signal for the current communication packet. In step S5, client B decodes the complete encoded bytecode based on the correspondence between 12 bits and Chinese characters, reassembles 318 bytes, and finally parses the complete 212 text contents to obtain the text to be communicated. For the current total of 212 text, if the traditional encoding method is used, 424 bytes are required. 424 = 3 * 120 + 64, which requires four communications. Without using the current preset communication protocol, the four communications have no context association, so after the B client receives the bytecode, it cannot reassemble it into a complete text and does not have the ability to communicate long text. For the current total of 212 texts, if the encoding method of this invention is used, 318 bytes of code are required, 318 = 2 * 10⁸ + 10², requiring three communications. Under the current preset communication protocol, this invention greatly improves the communication content of a single communication packet, reducing four communications to three communications. Furthermore, a communication protocol is proposed, which realizes context association and file integrity verification of long texts based on sequence number identification, and completes the long text communication function on the Beidou communication protocol.

[0033] Specifically, the following example shows the sending of a text containing a total of 216 Chinese characters and punctuation marks. Based on the current preset communication protocol, the current method only requires 1.5 bytes to represent one Chinese character. For a text containing 216 characters, 324 bytes can be used. 324 bytes represent three complete communication packets, represented as 108 + 108 + 108 = 324. Let the sending end 10 be client A, and the receiving end 20 be client B. Figure 5 As shown, the communication steps specifically include: Step S1: Client A reads the text content of the text to be communicated and encodes the text to be communicated based on the above encoding method to obtain the encoded bytecode, with a total of 324 bytecodes. Step S2: Based on the preset communication protocol, the bytecode is processed by packet splitting. Client A splits 324 bytes into 3 data contents of 108 bytes each. Based on the above three data contents, three communication packets of 120 bytes each are constructed respectively: Each communication packet's frame header consists of 2 bytes, fixed as two 255s; The data length is 2 bytes, and the content is 116; The sequence number is identified by two bytes, with contents of 1, 2, and 3 respectively; The total identifier is 2 bytes, and the content is 3; The data content consists of 108 bytes, including the encoded bytecode; The frame tail consists of 4 bytes, which are generated based on the frame header, data length, sequence number identifier, total identifier, and data content. The check content is generated based on CRC encoding. If the data content of the three communications is different, the generated frame tail will be different. Step S3: Client A sends the above three communication packets to Client B in three separate BeiDou short message communications. Client B receives three communication packets sent by client A in three separate transactions, and performs judgment and reassembly operations based on a preset communication protocol. Client B receives the first communication packet: The frame header is used to determine whether the current data is valid, and then the data length is read. The data length is 116, and then the remaining 116 bytes are read; Read the sequence number identifier and the total identifier to determine the total number of communication packets and the sequence number of the current communication packet in all communication packets; Read the data content and decode it based on the above encoding method, namely the correspondence between 12 bits and Chinese characters; Read the frame tail data to determine if the local communication content is complete. If it is incomplete, client B initiates a retransmission signal for the current communication packet. In step S5, client B decodes the complete encoded bytecode based on the correspondence between 12 bits and Chinese characters, reassembles 324 bytes, and finally parses 216 complete text contents to obtain the text to be communicated. Based on the sequence number identifier and total identifier, the system continuously reads three communication packets, assembles the complete communication content, and obtains the complete encoded bytecode. For the current total of 216 texts, if the traditional encoding method is used, four communications are required. Without using the current preset communication protocol, the four communications have no contextual relationship, so after the B client receives the bytecode, it cannot reassemble it into a complete text and does not have the ability to communicate long texts. For the current total of 216 texts, if the encoding method of this invention is used, 318 bytes of code are required, 324 = 3 * 108, which requires three communications. Under the current preset communication protocol, this invention greatly improves the communication content of a single communication packet, reducing four communications to three communications. Furthermore, a communication protocol is proposed, which realizes the context association and file integrity verification of long texts based on sequence number identification, and completes the long text communication function on the Beidou communication protocol.

[0034] Example 3 Unlike Embodiments 1 and 2, the present invention also provides an electronic device, including a memory and a processor, wherein the memory is used to store executable instructions, and the processor is used to read the executable instructions stored in the memory and execute the communication method in Embodiment 1 or the communication system in Embodiment 2.

[0035] In summary, this invention provides a communication method and system based on BeiDou short message service, which can solve the problems encountered in practical applications where BeiDou short message service has low communication frequency and limited number of bytes transmitted in a single transmission. By combining 12-bit encoding with the mapping relationship between Chinese characters, common punctuation marks and English letters, a more efficient text transmission capability is achieved under the 120-byte limit in a single transmission. At the same time, a custom preset communication protocol with integrity verification is designed to support reliable packet transmission of long texts.

[0036] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method based on BeiDou short message service, characterized in that, Specifically, the following steps are included: Step S1: The sending end obtains the text to be communicated, and encodes the text to be communicated based on the correspondence between 12 bits and Chinese characters to obtain the encoded bytecode. Step S2: The sending end processes the bytecode into packets according to a preset communication protocol to generate multiple communication packets; Step S3: The sending end sends multiple communication packets to the receiving end sequentially via BeiDou short message service; Step S4: The receiving end receives multiple communication packets, performs judgment and reassembly operations based on the preset communication protocol, and obtains complete encoded bytecode; Step S5: The receiving end decodes the complete encoded bytecode based on the correspondence between the 12 bits and Chinese characters to obtain the text to be communicated.

2. The communication method based on BeiDou short message service according to claim 1, characterized in that, The method for establishing the correspondence between the 12 bits and Chinese characters in step S1 is as follows: based on 3500 commonly used Chinese characters in the Chinese character list, a unique 12-bit code is assigned to each Chinese character according to the order of the characters in the Chinese character list. The value range of the 12-bit code corresponds to... A number.

3. The communication method based on BeiDou short message service according to claim 2, characterized in that, The 12-bit encoding is also used to represent common punctuation marks and English letters, which occupy the remaining 596 numerical bits.

4. The communication method based on BeiDou short message service according to claim 1, characterized in that, The preset communication protocol in step S2 includes a frame header, data length, sequence number identifier, total identifier, data content, and frame tail.

5. A communication method based on BeiDou short message service according to claim 4, characterized in that, The frame header is 2 bytes long, fixed at two 255s, and is used to identify the start of a new communication packet; The data length is 2 bytes, representing the total number of bytes for the sequence number identifier and the data content; The sequence number identifier is 2 bytes long and represents the sequence number order of the current communication packet in the overall communication packet; The total identifier is 2 bytes long and represents the total number of times the entire communication packet needs to be sent. The data content is 108 bytes long and is represented as bytecode containing communication content; The frame tail is 4 bytes long and is used as a checksum.

6. A communication method based on BeiDou short message service according to claim 4, characterized in that, The frame tail is generated based on the CRC check algorithm and is used to confirm that all bytecode of the frame header, data length, sequence number identifier, total identifier and data content are communicating normally. If the check is normal, the sending end treats the data byte to be sent as a binary number and performs a division operation on it using a preset polynomial. The remainder, i.e. the CRC check code, is appended to the data tail and sent together. If the check is abnormal, the receiving end initiates a retransmission request for the current communication packet.

7. A communication method based on BeiDou short message service according to claim 5, characterized in that, The specific method by which the sending end processes the bytecode into packets according to the preset communication protocol in step S2 is as follows: Calculate the total length of the encoded bytecode; Based on the maximum length of 108 bytes of data content in each communication packet, the total bytecode is divided into several data segments, with the last data segment having a length of no more than 108 bytes. Each data segment is assigned a corresponding sequence number and a unified total identifier. Combined with the frame header, data length, and frame trailer, a complete communication packet is constructed.

8. A communication method based on BeiDou short message service according to claim 2, characterized in that, The encoded bytes for each Chinese character, common punctuation mark, and English letter in the text to be communicated are 1.5 bytes.

9. A communication system based on BeiDou short message service, applied to the communication method based on BeiDou short message service as described in any one of claims 1-8, characterized in that, It includes a transmitter and a receiver, both of which are connected to the BeiDou satellite network for communication. The sending end includes a text acquisition module, an encoding module, a packet sub-module, and a sending module; The text acquisition module is used to acquire the text to be communicated; The encoding module is used to encode the text to be communicated based on the correspondence between 12 bits and Chinese characters, so as to obtain the encoded bytecode. The packet sub-module is used to sub-package the bytecode according to a preset communication protocol to generate multiple communication packets; The sending module is used to send multiple communication packets sequentially to the receiving end via BeiDou short message service; The receiving end includes a receiving module, a verification and reconstruction module, and a decoding module; The receiving module is used to receive multiple communication packets sent by the sending end; The verification and reassembly module is used to verify and reassemble multiple communication packets based on the preset communication protocol to obtain complete encoded bytecode. The decoding module is used to decode the complete encoded bytecode based on the correspondence between the 12 bits and Chinese characters to obtain the text to be communicated.

10. A communication system based on BeiDou short message service according to claim 9, characterized in that, The verification and reassembly module is also used to initiate a retransmission signal for the corresponding communication packet to the sending end when the verification finds that the communication packet is incomplete, and to perform sequential verification on the received multiple communication packets based on the sequence number identifier and the total identifier to ensure that the reassembly yields complete encoded bytecode.

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