Adaptive coding method and system for quantum direct communication

Abstract

The invention relates to a self-adaptive coding method and system for quantum direct communication, aiming at the technical problem of the existing single-path transmission quantum direct communication protocol, the decoding success rate can be improved by increasing a part of bits according to the decoding failure condition, the whole code word does not need to be retransmitted, and the coding efficiency is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of quantum communication, and particularly relates to an adaptive encoding method and system for quantum direct communication. BACKGROUND

[0002] Quantum communication refers to a technology of information transmission with quantum states as carriers, and its security is guaranteed by quantum physical principles, so it has high security. In the face of the rapid development of quantum computing today, the security of the classical cryptographic system based on mathematical complex problems is facing great challenges, and the research on quantum communication has attracted widespread attention and rapid development, becoming a relatively mature direction in the field of quantum information, and will play an important role in the next generation of secure communication.

[0003] Quantum communication technology mainly includes four branches of quantum key distribution (QKD), quantum secure direct communication (QSDC), quantum secret sharing and quantum teleportation. Quantum direct communication was proposed in 2000, and has a history of more than 20 years. Its development has experienced four stages:

[0004] (1) 2000-2004, the basic concepts and theories were established, and typical quantum direct communication protocols such as high-efficiency protocols based on entanglement, two-step protocols based on entanglement, and DL04 protocols based on single photons were proposed in this stage.

[0005] (2) 2005-2015, development protocol and application exploration stage, a large number of theoretical protocols were proposed, and the possible uses of quantum direct communication were widely explored.

[0006] (3) 2016-2019, principle experiment verification and prototype development stage. In this stage, the entanglement-based quantum direct communication protocol and the single-photon quantum direct communication scheme were verified in experiments. In particular, researchers proposed high-loss channel coding, quantum storage substitution, security quantitative analysis and other technologies, which solved many problems in the practicalization of quantum direct communication, and developed a quantum direct communication prototype with an information transmission rate of 50bps at a communication distance of 1.5km optical fiber.

[0007] (4) Since 2020, product development and practicalization promotion. The typical performance of the communication prototype in this stage is 10km@4kbps, which can realize real-time secure transmission of text, pictures and voice files, and can realize 100km quantum direct communication using low-loss optical fiber.

[0008] With the substantial improvement of computer computing power and the emergence of quantum computers, the crisis of traditional cryptographic systems and secure communication technology has emerged. Quantum direct communication is currently known to be a communication method that can be used to counter quantum computers. Quantum direct communication is faced with high loss and high error code. Currently, quantum direct communication uses a fixed code rate encoding method. SUMMARY

[0009] To solve the technical problems of the existing single-channel transmission quantum direct communication protocol, the application provides an adaptive encoding scheme for quantum direct communication, which can increase the decoding success rate by increasing part of the bits without retransmitting the entire code word according to the decoding failure condition, thereby improving the encoding efficiency.

[0010] According to a first aspect of the application, an adaptive encoding method for quantum direct communication is provided, which is applied to a sending end and characterized by comprising:

[0011] (a) encoding input information using a channel encoding matrix to generate an encoding code word, wherein the encoding code word includes a set of information bits and check bits;

[0012] (b) determining check bits to be transmitted from the set of check bits according to a current error code rate to generate current information to be transmitted, wherein the current information to be transmitted includes the information bits and the check bits to be transmitted;

[0013] (c) determining a spreading sequence according to a current receiving rate;

[0014] (d) spreading the current information to be transmitted using the spreading sequence to generate spread information;

[0015] (e) loading the spread information through a quantum channel to determine and send quantum state information through the quantum channel;

[0016] (f) determining retransmission bit information in response to decoding failure of the receiving end, wherein the retransmission bit information includes check bits or check bits and information bits,

[0017] (g) determining the determined retransmission bit information as the current information to be transmitted, and returning to step (d).

[0018] According to a second aspect of the application, an adaptive encoding method for quantum direct communication is provided, which is applied to a receiving end and characterized by comprising:

[0019] (a) decoding current information from the sending end using a decoding matrix currently corresponding to the sending end to generate and send a decoding result;

[0020] (b) sending decoding failure result information to the sending end in case of decoding failure;

[0021] (c) receiving the retransmitted bit information from the sending end;

[0022] (d) combining the retransmitted bit information with the information from the sending end before the current retransmission, obtaining combined information, and determining the combined information as current information;

[0023] (e) determining the current corresponding decoding matrix according to the retransmitted check bit, and returning to step (a).

[0024] According to a third aspect of the present application, an adaptive encoding system for quantum direct communication is provided, characterized in that it comprises:

[0025] a sending end configured to perform the method according to the first aspect; and

[0026] a receiving end configured to perform the method according to the second aspect.

[0027] According to a fourth aspect of the present application, an electronic device is provided, characterized in that it comprises a memory and a processor, wherein the memory stores a computer program, and the processor implements the method according to the first aspect and the second aspect when executing the computer program stored in the memory.

[0028] According to a fifth aspect of the present application, a computer readable storage medium is provided, characterized in that it stores a computer program, and the computer program is executed by a processor to implement the method according to the first aspect and the second aspect.

[0029] The adaptive encoding method and system for quantum direct communication provided by the present application can increase part of the bits, especially part of the check bits, to improve the decoding success rate according to the decoding failure condition, without retransmitting the entire codeword, thereby improving the encoding efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art according to these drawings without departing from the scope of the present application.

[0031] Figure 1 is a flowchart of the adaptive encoding system for quantum direct communication according to the embodiments of the present application.

[0032] Figure 2is a frame error rate curve diagram of five code rates.

[0033] Figure 3 is a schematic diagram of an LDPC base matrix.

[0034] Figure 4 is a flowchart of an adaptive encoding method for quantum direct communication performed by a sending end according to an embodiment of the present application.

[0035] Figure 5 is a flowchart of an adaptive encoding method for quantum direct communication performed by a receiving end according to an embodiment of the present application.

[0036] Figure 6 is a structural schematic diagram of an electronic device provided by the present application. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0038] Figure 1 is a flowchart of an adaptive encoding system for quantum direct communication according to an embodiment of the present application. In Figure 1 The system shown in the figure includes a sending end and a receiving end, and quantum direct communication is adopted between the two, and at the same time, a classical communication channel is provided, such as an optical fiber channel, a wireless channel, etc. In an embodiment, the channel coding adopted between the sending end and the receiving end can be an LDPC (Low Density Parity Check Code, low density parity check code) code, a polar code, etc. For the convenience of understanding, the following mainly describes the LDPC code as the channel coding.

[0039] In an embodiment, the encoding information input by the sending end is encoded by the encoding matrix to generate an encoding code word N, and the encoding code word N includes the encoding information and a check code word set {m1, m2, …, m n}, wherein the encoding information can include k information bits, and the check code word set includes n check bits. The sending end determines m check bits {m1, m2, …, m m} to be transmitted from the check bit set according to the current bit error rate (known value), so as to generate the current information to be transmitted {k information bits, m check bits}. Figure 2 is a frame error rate curve diagram of five code rates. For example, for a bit error rate of 3%, in order to achieve a frame error rate of 10 -3The frame error rate requirement is met by the middle curve (the third one from left to right), while other curves adjacent to the middle curve (e.g., the second one from left to right) do not. Although the bit rates of these two curves differ only slightly (7.94E-4 and 9.00E-4), the difference is significant in terms of frame error rate. This application determines m parity bits to be transmitted from the parity bit set based on the current bit error rate. These m parity bits are determined according to the bit rate that meets the frame error rate requirement and can be the minimum value among the number of parity bits that meet the frame error rate requirement. By determining the number of parity bits to be transmitted (or the bit rate), the amount of parity information sent can be minimized while closely meeting the frame error rate requirement, thereby improving transmission efficiency. Based on the characteristics of quantum direct communication systems, accurate bit error estimation can be performed, and the parity check matrix can be selected accordingly.

[0040] Then, or simultaneously, the transmitter selects a spreading factor L based on the system's receive rate (a known value), and uses quantum random numbers to generate two L-bit long quantum random sequences p0 = {p 0,1 ,p 0,2 ,p 0,3 ,…,p 0,L} and p1={p 1,1 ,p 1,2 ,p 1,3 ,…,p 1,L}, replace each bit in the currently transmitted information with a random sequence p0 or p1 of length L. In an optional embodiment, as Figure 1 As shown, encryption and INCUM (Increase Capacity Using Masking) processing can be performed on the spread spectrum information sequence.

[0041] Next, the processed information sequence can be loaded through a quantum channel. For example, quantum state operations can be performed on 0 or 1, including phase operations, polarization operations, etc., and the information can be sent through the quantum channel.

[0042] For the receiving end, the quantum state information from the transmitting end is detected to obtain the detection result. Then, the receiving end uses the spreading sequence p0 or p1 corresponding to the transmitting end for despreading to obtain the despread information and calculate the soft information required for decoding. In an optional embodiment, the despread information sequence can be decrypted and processed using INCUM. Then, the receiving end selects the corresponding decoding matrix according to the encoding matrix parameters transmitted from the transmitting end through the classical channel for decoding, and can transmit the decoding result back to the transmitting end through the classical channel.

[0043] If the decoding result is correct, the transmitter sends the next frame of encoded information. If the decoding result fails, it can determine the retransmitted information and repeat the above-described spreading and quantum channel loading process. After receiving the retransmitted soft information, the receiver combines the retransmitted soft information with the previously received soft information and performs joint re-decoding. If decoding fails, it can continue to receive the retransmitted information from the transmitter and perform joint re-decoding again until the decoding is correct, all check bits in the check codeword set are sent, or the preset number of retransmissions is reached.

[0044] An adaptive coding scheme for direct quantum communication between the transmitter and receiver can be explained through a specific example.

[0045] (1) For a single-vector quantum direct communication system with a transmission distance of 50km, a receiving rate of 1.3‰ and a bit error rate of about 3%, the input information k is, for example, 1040 bits, and the total length of the encoded information is N = 5408 bits;

[0046] (2) By Figure 2 It can be seen that, under the current bit error rate of 3%, the frame error rate is less than 1.0E-3. Based on the bit error rate, the base matrix (7,17) is selected, and the required codeword length is N1 = Z. c *17 = 1768, where Z c Let be the expansion factor of the basis matrix; where the choice of the basis matrix can be as follows: Figure 3 As shown.

[0047] (3) Based on the receiver rate, the spreading length L = 740 is calculated, and the bits 0 of codeword N1 can be mapped to a random sequence p0 = {p 0,1 ,p 0,2 ,p 0,3 ,…,p 0,L}, map bit 1 to p1 = {p 1,1 ,p 1,2 ,p 1,3 ,…,p 1,L A single frame of data sent contains a total of C. i =L*N1=1308320 bits;

[0048] (4) Send C via quantum channel i = 1,308,320 bits;

[0049] (5) Using the classic channel transmission code rate (e.g., transmission code rate R = 7.94E-4) and spreading length L = 740 parameters, at the receiving end, the soft information required for decoding is calculated based on the spreading sequence p0 or p1, and the corresponding soft information sequence LLR is generated. i ;

[0050] (6) Select the corresponding decoding matrix according to the transmission code rate (e.g., transmission code rate R = 7.94E-4) for decoding, and transmit the decoding result to the sending end through the classical channel;

[0051] (7) If the decoding is successful, return to step (1); if the decoding fails, return to step (8).

[0052] (8) Determine the information that needs to be retransmitted. In one specific embodiment, the retransmitted information may be a preset number of check bits after the already transmitted check bits, for example, adding 1 Z check bits to be sent. c =104;

[0053] (9) Calculate the verification data to be sent, C i ′=Z c *L = 76960 bits;

[0054] (10) Sending C via quantum channel i ′ = 76960 bits;

[0055] (11) Transmit the transmission code rate (e.g., transmission code rate R = 7.50E-4), spreading factor L = 740, and other parameters through a classical channel. At the transmitting end, calculate the soft information LLR required for decoding based on the spreading sequence p0 or p1. i ′;

[0056] (12) The receiving end combines the previously transmitted soft information LLR i And the soft information LLR received this time i Perform joint decoding. If the decoding is successful, return (1). If the decoding fails, return (8). Continue until the decoding is successful, all the check bits in the check code set are sent, or the preset number of retransmissions is reached.

[0057] Based on the aforementioned system, according to one aspect of this application, an adaptive coding method for quantum direct communication executed by the transmitting end is provided. For example... Figure 4 As shown, the method includes:

[0058] Step S401: Encode the input information using a channel coding matrix to generate coded codewords, wherein the coded codewords include a set of information bits and a set of check bits.

[0059] In one embodiment, the encoded information input by the transmitting end is encoded using an encoding matrix to generate an encoded codeword N. The encoded codeword N includes the encoded information and a set of check codewords {m1, m2, ..., m}. n}, where the encoded information may include k information bits, and the check code set includes n check bits.

[0060] In step S402, the check bits to be transmitted are determined from the check bit set according to the current bit error rate, to generate the current information to be transmitted, wherein the current information to be transmitted includes the information bits and the check bits to be transmitted.

[0061] In one embodiment, the sending end determines m check bits to be transmitted {m1, m2, …, m m} from the check bit set according to the current bit error rate (known value), to generate the current information to be transmitted {k information bits, m check bits}. In one embodiment, when the check bits to be transmitted are determined from the check bit set, the corresponding encoding matrix parameters are determined, including the corresponding encoding code rate, for example, R = 7.94E-4. The sending end can send the encoding matrix parameters to the receiving end through a classical channel.

[0062] In step S403, the spreading sequence is determined according to the current reception rate.

[0063] In step S404, the current information to be transmitted is spread using the spreading sequence, to generate the spread information.

[0064] In step S405, the spread information is loaded through the quantum channel to determine and send the quantum state information through the quantum channel.

[0065] In one embodiment, the sending end selects the spreading factor L according to the system reception rate (known value), and generates two L-bit long quantum random sequences p0 = {p 0,1 ,p 0,2 ,p 0,3 ,…,p 0,L} and p1 = {p 1,1 ,p 1,2 ,p 1,3 ,…,p 1,L} using quantum random numbers at the sending end, and replaces each bit in the current information to be transmitted with the L-bit long random sequence p0 or p1. Next, the processed information sequence can be loaded through the quantum channel, for example, the quantum state operation of 0 or 1, including the operation on the phase, the operation on the polarization, etc., to send the information through the quantum channel.

[0066] In step S406, the bit information for retransmission is determined in response to the decoding failure of the receiving end.

[0067] In one embodiment, in the case of decoding failure, the receiving end sends the decoding result to the sending end, and the sending end can determine the bit information for retransmission. The bit information for retransmission includes the check bits or the check bits and the information bits.

[0068] In an embodiment, the retransmitted bit information can be a preset number of check bits after the transmitted check bits in the check bit set. For example, the check bit set includes 1000 check bits, the first 100 check bits have been transmitted, and the retransmitted check bits can be the check bits after the 100 check bits. The number of retransmitted check bits can be predetermined, for example, 1, 2, etc., which is not limited in the present application.

[0069] In a specific implementation, the number of retransmitted check bits can be determined according to the decoding result of the receiving end for this transmission. Generally, the higher the error rate of the decoding result, the more the number of retransmitted check bits can be.

[0070] In an embodiment, the receiving end multiplies the received codeword with the check matrix, and under the same bit number, the more the number of 0s, the better the check result, and the number of retransmitted check bits can be less, and vice versa. The sending end can determine the number of retransmitted check bits according to the check result returned by the receiving end; and determine the check bits in the check bit set after the transmitted check bits as the retransmitted check bits.

[0071] In an embodiment, the receiving end can determine which positions are not detected in the process of detecting the quantum signal of the quantum channel, thereby determining the positions of undetected information, and forming indication information (first indication information), and sending the indication information to the sending end through the classical channel. The sending end can determine the information in the corresponding position as the retransmitted bit information according to the indication information. The retransmitted bit information can include check bits and / or information bits. In an embodiment, after receiving the indication information from the receiving end, the sending end can send the position information of the retransmitted bit information to the receiving end through the classical communication channel.

[0072] In an embodiment, the receiving end can determine the positions of possible errors in the codeword N according to the check matrix in the process of decoding the received soft information, thereby determining the positions of the bit information that needs to be retransmitted, to generate position indication information (second indication information) indicating the bit information that needs to be retransmitted. The sending end receives the indication information and determines the retransmitted bit information according to the indication information. The retransmitted bit can be a check bit, or a check bit and an information bit.

[0073] To facilitate understanding how to determine the position of possible errors according to the check matrix in the decoding process, a specific embodiment is described below. Channel coding uses an LDPC code, which is a (n, k) linear block code, with a code length of n and an information sequence length of k. The number of 1s in the check matrix is much smaller than the number of 0s, and the check matrix has sparsity. The dimension of the check matrix H is m x n, each row corresponds to a check equation, and each column corresponds to a bit of the code word. The number of non-zero elements in each row is called the row weight, and the number of non-zero elements in each column is called the column weight. The following is a 5 x 10 check matrix and its corresponding check equations:

[0074]

[0075] As can be seen from the right side of the check equation, when all code words satisfy, the right side is equal to 0; and when the result of a row is not 0, it can be known that the element corresponding to the row may have an error, for example, if the first row does not satisfy 0, it can be known that the bit sequence {v2, v4, v6, v8} may have an error, and the sequence can be required to be retransmitted.

[0076] It can be understood that the above-mentioned ways of determining the retransmission bit information can be used alone or in combination, as long as there is no conflict between these determination methods. For example, the sending end can determine the retransmission bit information by combining the first indication information and the second indication information.

[0077] Step S407, determine the retransmission bit information as the current information to be transmitted, and return to step 404.

[0078] In one embodiment, the sending end transmits the next frame of encoded information if the decoding result is correct; and if the decoding result fails, the retransmission information can be determined, and the above-mentioned spreading and quantum channel loading process is repeated.

[0079] On the basis of the above-mentioned system, according to another aspect of the present application, a receiving end executed adaptive encoding method for quantum direct communication is provided. As shown in Figure 5 the method comprises:

[0080] Step S501, detecting the quantum state information from the sending end to obtain a detection result;

[0081] Step S502, despread using the spreading sequence corresponding to the sending end to obtain despread information;

[0082] Step S503, decoding the current information from the sending end using the decoding matrix corresponding to the current sending end to generate and send a decoding result.

[0083] In one embodiment, the receiving end detects the quantum state information from the sending end, obtains a detection result, then despread the despread information using the corresponding spreading sequence p0 or p1 of the sending end, and obtains soft information required for decoding. Then, the receiving end decodes using the corresponding decoding matrix selected according to the encoding matrix parameters transmitted by the sending end through the classical channel, and can transmit the decoding result to the sending end through the classical channel.

[0084] In step S504, the receiving end sends decoding failure result information to the sending end in case of decoding failure.

[0085] In one embodiment, the receiving end sends the decoding failure result to the sending end in case of decoding failure, and the sending end can determine the retransmission bit information. The retransmission bit information includes check bits or check bits and information bits.

[0086] In one embodiment, the retransmission bit information can be a preset number of check bits after the transmitted check bits in the check bit set. For example, the check bit set includes 1000 check bits, the first 100 check bits have been transmitted, and the retransmission can be performed on the check bits after the 100 check bits. The number of retransmission check bits can be predetermined, for example, 1, 2, etc., which is not limited in the present application.

[0087] In one embodiment, the receiving end can determine which positions are not detected during the detection of the quantum signal of the quantum channel, thereby determining the positions of undetected information and forming indication information (first indication information), and sending the indication information to the sending end through the classical channel. The sending end can determine the corresponding position information as the retransmission bit information according to the indication information. The retransmission bit information can include check bits and / or information bits. In one embodiment, after receiving the indication information from the receiving end, the sending end can send the position information of the retransmission bit information to the receiving end through the classical communication channel.

[0088] In one embodiment, after the receiving end multiplies the received codeword with the check matrix, the more the number of 0s under the same bit number, the better the check result, and the fewer the number of retransmission check bits, or vice versa. The sending end can determine the number of retransmission check bits according to the check result returned by the receiving end, and determine the determined number of check bits after the transmitted check bits in the check bit set as the retransmission check bits.

[0089] In one embodiment, the receiving end can determine the positions of the possible errors in the code word N according to the check matrix during decoding of the received soft information, so as to determine the positions of the bits that need to be retransmitted, to generate position indication information (second indication information) indicating the positions of the bits that need to be retransmitted, and the sending end receives the indication information and determines the bits to be retransmitted according to the indication information. The bits to be retransmitted can be check bits or can be check bits and information bits.

[0090] Step S505: receiving the bit information retransmitted by the sending end.

[0091] Step S506: combining the bit information retransmitted by the sending end with the information from the sending end before the current retransmission, obtaining combined information, and determining the combined information as the current information.

[0092] Step S507: determining the current corresponding decoding matrix according to the retransmitted check bits, and returning to step S503.

[0093] In one embodiment, the sending end determines the information to be retransmitted, and repeats the process of spread spectrum and quantum channel loading. The receiving end combines the retransmitted soft information with the previously received soft information after receiving the retransmitted soft information, and performs joint re-decoding. If decoding fails, the receiving end can continue to receive the information retransmitted by the sending end, and perform joint re-decoding again until decoding is correct, all check bits in the check code word set are transmitted, or a preset number of retransmissions is reached.

[0094] According to the adaptive encoding method and system for quantum direct communication provided in the present application, the decoding success rate can be improved by increasing some bits, especially some check bits, according to the decoding failure condition, without retransmitting the entire code word, thereby improving the encoding efficiency.

[0095] In the above embodiments, the description of each embodiment focuses on different aspects, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0096] It should be noted that, for the above-mentioned method embodiments, in order to simply describe, they are all expressed as a series of action combinations, but those skilled in the art should know that the present application is not limited to the action order described, because according to the present application, certain steps can be performed in other order or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification all belong to optional embodiments, and the actions and modules involved are not necessarily required by the present application.

[0097] In several embodiments provided in the present application, it should be understood that the disclosed apparatus can be implemented in other manners. For example, the division of the apparatus embodiments described above is merely a logical function division, and there can be another division manner in actual implementation. For example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between different units, or the among different units, can be indirect couplings or communication connections through some interfaces, devices or units, and can be in electrical, mechanical or other forms.

[0098] Referring to Figure 6 , Figure 6 An electronic device is provided, including a processor and a memory. The memory stores computer instructions or one or more programs, which, when executed by the processor, cause the processor to execute the computer instructions to implement the method and refinements as shown in Figure 4 and Figure 5 .

[0099] It should be understood that the above-described apparatus embodiments are merely illustrative, and the disclosed apparatus can also be implemented in other manners. For example, the division of the units / modules in the above-described embodiments is merely a logical function division, and there can be another division manner in actual implementation. For example, a plurality of units, modules or components can be combined, or can be integrated into another system, or some features can be ignored or not executed.

[0100] In addition, each functional unit / module in each embodiment of the present application can be integrated into one unit / module, or each unit / module can exist physically, or two or more units / modules can be integrated together. The integrated unit / module can be implemented in the form of hardware or in the form of a software program module.

[0101] The integrated units / modules, if implemented in the form of hardware, can be digital circuits, analog circuits, etc. The physical implementation of the hardware structure includes, but is not limited to, transistors, memristors, etc. Unless otherwise specified, the processor or chip can be any appropriate hardware processor, such as a CPU, a GPU, an FPGA, a DSP, an ASIC, etc. Unless otherwise specified, the on-chip cache, off-chip memory, storage can be any appropriate magnetic storage medium or magneto-optical storage medium, such as resistive random access memory (RRAM), dynamic random access memory (DRAM), static random access memory (SRAM), enhanced dynamic random access memory (EDRAM), high-bandwidth memory (HBM), hybrid memory cube (HMC), etc.

[0102] If the integrated units / modules are implemented in the form of software program modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the present application, essentially or the part that contributes to the prior art, or all or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, and includes a number of instructions for making a computer electronic device (which can be a personal computer, a server, or a network electronic device, etc.) execute all or part of the steps of the method described in various embodiments of the present disclosure. The aforementioned storage medium includes: a U disk, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk, and various program code storage media.

[0103] The embodiments of the present application also provide a computer readable storage medium, which stores one or more computer programs, and when the one or more computer programs are executed by a plurality of processors, the processors execute the method and detailed solutions shown in the above embodiments. Figure 4 and Figure 5 The embodiments of the present application also provide a computer readable storage medium, which stores one or more computer programs, and when the one or more computer programs are executed by a plurality of processors, the processors execute the method and detailed solutions shown in the above embodiments.

[0104] The embodiments of the present application also provide a computer program product, which contains a computer program, and when the computer program runs on a computer, the computer executes the method of any of the above embodiments.

[0105] Reference within this specification to features, advantages, or similar language does not imply that all of the features and advantages that can be realized from the present solution should be or are contained in, or must be realized in, any single

[0106] Furthermore, the described features, advantages, and characteristics of the present solution can be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize, in light of the description herein, that the present solution can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages can be realized through the techniques of the present solution that may not appear in the following written description.

[0107] The above detailed description of the application has been presented for the purposes of clarity and understanding. The description provided in this document is intended to be illustrative and not restrictive on the scope of the application. The scope of the application is defined by the appended claims. Various changes and modifications could be suggested by those skilled in the art, and it is intended that the application encompass such changes and modifications as fall within the scope of the appended claims.

Claims

1. An adaptive encoding method for quantum direct communication, applied to a sending end, characterized in that, The method comprises: (a) encoding input information using a channel encoding matrix to generate an encoded codeword, wherein the encoded codeword comprises a set of information bits and check bits; (b) determining check bits to be transmitted from the set of check bits according to a current bit error rate to generate current information to be transmitted, wherein the current information to be transmitted comprises the information bits and the check bits to be transmitted; (c) determining a spreading sequence according to a current reception rate; (d) spreading the current information to be transmitted using the spreading sequence to generate spread information; (e) loading the spread information onto a quantum channel to determine quantum state information and send the quantum state information through the quantum channel; (f) in response to decoding failure at the receiving end, determining retransmission bit information, wherein the retransmission bit information comprises check bits or check bits and information bits, (g) determining the retransmission bit information as current information to be transmitted and returning to step (d).

2. The method of claim 1, wherein, Step (f) comprises: In response to decoding failure at the receiving end, determining a preset number of check bits after the transmitted check bits in the set of check bits as retransmission bit information.

3. The method of claim 1, wherein, Step (f) comprises: Receiving first indication information returned by the receiving end, wherein the first indication information comprises a position of undetected information; According to the first indication information, determining information at the corresponding position as retransmission bit information.

4. The method of claim 1, wherein, Step (f) comprises: Receiving a check result returned by the receiving end to determine the number of retransmission check bits; Determining a number of check bits after the transmitted check bits in the set of check bits as retransmission check bits.

5. The method of claim 3, wherein, Further comprising: Sending position information of the retransmission bit information to the receiving end through a classical communication channel.

6. The method of claim 1, wherein, Step (f) comprises: Receiving second indication information of positions of bits requiring retransmission determined by the receiving end according to a check matrix of a channel decoding process; According to the second indication information, determining retransmission bit information.

7. An adaptive coding method for quantum direct communication, applied to a receiving end, characterized in that, The method comprises: (a) decoding current information from the sending end using a decoding matrix corresponding to the sending end to generate and send decoding results; (b) in the case of decoding failure, sending decoding failure result information to the sending end; (c) receiving retransmission bit information from the sending end; (d) combining the retransmission bit information with information from the sending end before retransmission to obtain combined information, and determining the combined information as current information; and (e) determining a decoding matrix corresponding to the current retransmission according to the retransmission check bits, and returning to step (a). Before step (a), the method further comprises:

8. The method of claim 7, wherein, Detecting quantum state information from the sending end to obtain detection results; and Despreading using a spreading sequence corresponding to the sending end to obtain despread information. Step (b) comprises:

9. The method of claim 8, wherein, In the case where the detection results show that there is a position of undetected information, sending first indication information of the position of undetected information to the sending end. Step (b) comprises:

10. The method of claim 7 or 8, wherein, ​ The check result in the decoding process is sent to the sending end, so that the sending end determines the number of retransmission check bits according to the check result.

11. The method of claim 7 or 8, wherein, Step (b) comprises: determining the position of the bit information that needs to be retransmitted according to the check matrix of the channel decoding process; and sending the second indication information of the position of the bit information that needs to be retransmitted to the sending end.

12. An adaptive coding system for quantum direct communication, characterized by comprises: a sending end for performing the method of any one of claims 1 to 6; and a receiving end for performing the method of any one of claims 7 to 11.

13. An electronic device, comprising: comprises a memory and a processor, the memory has a computer program stored thereon, and the processor implements the method of any one of claims 1 to 11 when executing the computer program stored on the memory.

14. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, and the computer program is executed by the processor to implement the method of any one of claims 1 to 11. The computer readable storage medium stores a computer program, and the computer program is executed by the processor to implement the method of any one of claims 1 to 11.

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