Optical signal generation method based on sparse orthogonal space-time code multi-dimensional modulation

Abstract

The invention discloses an optical signal generation method based on sparse orthogonal space-time code multi-dimensional modulation. The method comprises the following steps: randomly dividing original data to be sent into first data, second data, third data and fourth data; respectively performing codebook constellation mapping on the first data, the second data, the third data and the fourth data to obtain a first codebook mapping signal, a second codebook mapping signal, a third codebook mapping signal and a fourth codebook mapping signal; performing sparse code division multiplexing on the first codebook mapping signal, the second codebook mapping signal, the third codebook mapping signal and the fourth codebook mapping signal to obtain a first sparse code signal, a second sparse code signal, a third sparse code signal and a fourth sparse code signal; performing orthogonal space-time block coding modulation according to the first sparse code signal, the second sparse code signal, the third sparse code signal and the fourth sparse code signal to generate a modulation signal; and inputting the modulation signal into a hollow-core optical fiber channel for transmission.

Description

Technical Field

[0001] The present application belongs to the field of optical transmission communication technology, and specifically relates to a method for generating optical signals based on sparse orthogonal space-time code multi-dimensional modulation. Background Art

[0002] In recent years, with the surge in backbone network communication traffic, the expansion of communication systems has become an eternal topic. In addition to soft expansion, the most effective way to expand channel capacity is hardware expansion. As an important transmission medium, optical fiber has become a bridge for information connection, and the ability of optical fiber transmission is an important factor affecting system performance. In order to improve the bandwidth, speed and reliability of information transmission, hollow-core optical fiber technology has emerged. Hollow-core optical fiber is a fiber structure that transmits optical signals in the center of the air. Unlike multi-core optical fiber, hollow-core optical fiber is composed of an air core layer surrounded by a layer of material with a periodic structure. The optical signal is transmitted through waveguide mode coupling between the air core and the material surrounding it. This structure allows the optical signal to be transmitted at a near-vacuum speed in the center of the air, with the characteristics of low latency, and can support the transmission of multiple modes, making the transmission frequency range of hollow-core optical fiber wider than that of traditional optical fiber, and can meet the bandwidth and speed requirements of future high-speed communication systems. Hollow-core optical transmission is considered to be the most promising optical transmission technology in the future, but its application in optical communication systems is still in the preliminary research stage. There are various problems in hollow-core optical fiber structure and drawing, multiplexing and demultiplexing devices, hollow-core multiplexing coding modulation technology and channel equalization, which have not yet been solved.

[0003] Therefore, considering the characteristics of hollow-core fiber channels, how to use efficient coding, modulation and demodulation technology to improve system performance is also one of the problems that need to be solved at present. Summary of the invention

[0004] Space-time coding technology is an efficient multi-channel coding technology in the field of wireless communication. It can transmit information by utilizing the spatial and temporal correlation of signals on different transmission and reception paths without sacrificing channel bandwidth, and can provide certain coding gain and diversity gain for the communication system at the receiving end. At present, the most common space-time coding schemes are the following three: space-time division trellis code, space-time block code and space-time layered code. Space-time layered code is the earliest space-time coding method proposed. Its biggest advantage is that the coding process is very simple and easy, but its performance is the worst among the three existing space-time coding methods. Space-time division trellis code is another space-time coding technology proposed after the emergence of space-time layered code. It combines the idea of ​​joint optimization of coding and modulation, and can use the structural information redundancy to reduce the interference of signal noise without losing the transmission bandwidth. It can not only obtain a large diversity gain, but also provide very good coding gain, and at the same time improve the spectrum utilization of the system. Therefore, it is a better solution under the comprehensive consideration of the complexity, performance and spectrum utilization of coding. However, the decoding process of space-time grid codes is very cumbersome and complicated, and when the number of transmissions is fixed, the complexity of its decoding increases exponentially with the increase of signal transmission rate. Therefore, when high-speed data transmission is used, space-time block coding is usually used. Its biggest advantage is that it uses a simple maximum likelihood decoding criterion to obtain the maximum transmission rate and the maximum diversity gain. It is a simple and effective space-time coding scheme. Through space-time block group coding, the system takes advantage of multiple transmissions and multiple receptions at the same time, which not only improves the capacity and transmission rate of optical fiber signals, but also improves the reliability of signals.

[0005] As a non-orthogonal multiple access technology based on the code domain, sparse code multiple access has excellent shaping coding gain and error-free propagation characteristics compared with the existing non-orthogonal multiple access technology (NOMA). Compared with orthogonal frequency division multiple access, it can provide overload gain in the number of supported users and improve spectrum utilization. First, the codebook can be flexibly designed to flexibly provide optimization dimensions according to the specific system performance requirements of different future system scenarios, including the number of codewords, spread spectrum length, and the number of non-zero codewords. It can also be specially designed for different scenarios from some different system measurement dimensions such as coverage, number of connections, and capacity; secondly, according to the sparsity of the codewords, a low complexity algorithm (MPA) can be used at the receiving end to approximate the demodulation of each user's data. MPA can use iterative characteristics for iterative solution, and combined with channel coding to achieve Turbo decoding, while improving performance and controlling the demodulation complexity within a certain range.

[0006] Purpose: In view of at least one of the above technical problems, the present application provides a method for generating optical signals based on sparse orthogonal space-time code multi-dimensional modulation, by performing multi-dimensional joint modulation of sparse code division and space-time coding and applying it to an air-core optical transmission system, thereby realizing multi-dimensional coding modulation of the air-core system and improving the transmission efficiency, quality and transmission reliability of the air-core transmission system.

[0007] The technical solution adopted in this application is:

[0008] In a first aspect, the present application provides a method for generating an optical signal based on sparse orthogonal space-time code multidimensional modulation, comprising:

[0009] S1. Randomly divide the original data to be sent into first data, second data, third data, and fourth data;

[0010] S2. Perform codebook constellation mapping on the first data, the second data, the third data, and the fourth data respectively to obtain a first codebook mapping signal, a second codebook mapping signal, a third codebook mapping signal, and a fourth codebook mapping signal;

[0011] S3, performing sparse code division multiplexing on the first codebook mapping signal, the second codebook mapping signal, the third codebook mapping signal, and the fourth codebook mapping signal to obtain a first sparse code signal, a second sparse code signal, a third sparse code signal, and a fourth sparse code signal;

[0012] S4, performing orthogonal space-time block coding modulation according to the first sparse code signal, the second sparse code signal, the third sparse code signal, and the fourth sparse code signal to generate a modulated signal;

[0013] S5. Input the modulated signal into a hollow-core optical fiber channel for transmission.

[0014] In a second aspect, the present application provides an optical signal generating device based on sparse orthogonal space-time code multi-dimensional modulation, including a processor and a storage medium;

[0015] The storage medium is used to store instructions;

[0016] The processor is configured to operate according to the instructions to execute the method according to the first aspect.

[0017] In a third aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the method described in the first aspect when executed by a processor.

[0018] In a fourth aspect, the present application provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the method of the first aspect when executing the computer program.

[0019] In a fifth aspect, the present application provides a computer program product, comprising a computer program, which implements the method described in the first aspect when executed by a processor.

[0020] Beneficial effect: The optical signal generation method based on sparse orthogonal space-time code multi-dimensional modulation provided by the present application has the following advantages: sparse orthogonal space-time code multi-dimensional modulation is realized by using sparse code division technology and orthogonal space-time coding joint modulation, so that code chips, time slots, and hollow core channels are orthogonalized, inter-symbol crosstalk and inter-code crosstalk are reduced, and joint multiplexing coding modulation of each channel is realized according to the channel characteristics, spectrum utilization efficiency and transmission efficiency are improved, interference is reduced and transmission reliability is enhanced. By multi-dimensionally jointly modulating sparse code division and space-time coding and applying them to the hollow core optical transmission system, multi-dimensional coding modulation of the hollow core system is realized. Since sparse code division multiple access technology has the advantages of high spectrum utilization, strong anti-interference ability, good system compatibility, etc., and space-time coding technology realizes multiple transmission and multiple reception by using array processing technology, it can effectively offset fading and improve spectrum efficiency. By combining the two for multi-dimensional modulation and applying them to the hollow core optical fiber transmission system, it can not only achieve higher efficiency of optical fiber transmission and enhance anti-interference ability, but also improve the reliability of optical fiber transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of a process of generating an optical signal based on sparse orthogonal space-time code multi-dimensional modulation according to an embodiment of the present application;

[0022] Figure 2 A schematic diagram of codebook bits and codebook mapping according to the sparse code division technology in an embodiment of the present application;

[0023] Figure 3 A schematic diagram of a multi-user codebook allocation model according to an embodiment of the present application;

[0024] Figure 4 It is a schematic diagram of the principle of orthogonal space-time block coding according to an embodiment of the present application;

[0025] Figure 5 A schematic diagram of a hollow-core optical fiber communication transmission system according to an embodiment of the present application;

[0026] Figure 6 Schematic diagram of a BER bit error rate simulation curve according to an embodiment of the present application. DETAILED DESCRIPTION

[0027] The present application is further described below in conjunction with the accompanying drawings and embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and cannot be used to limit the protection scope of the present application.

[0028] In the description of this application, "several" means more than one, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number itself, and "above", "below", "within", etc. are understood to include the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0029] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0030] The term "and / or" is only a description of the association relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " generally indicates that the related objects are in an "or" relationship.

[0031] Embodiment 1: This embodiment provides a method for generating an optical signal based on sparse orthogonal space-time code multi-dimensional modulation, such as Figure 1 As shown, executed at the sending end, the method includes:

[0032] S1. Randomly divide the original data to be sent into first data, second data, third data, and fourth data;

[0033] S2. Perform codebook constellation mapping on the first data, the second data, the third data, and the fourth data respectively to obtain a first codebook mapping signal, a second codebook mapping signal, a third codebook mapping signal, and a fourth codebook mapping signal;

[0034] S3, performing sparse code division multiplexing on the first codebook mapping signal, the second codebook mapping signal, the third codebook mapping signal, and the fourth codebook mapping signal to obtain a first sparse code signal, a second sparse code signal, a third sparse code signal, and a fourth sparse code signal;

[0035] S4, performing orthogonal space-time block coding modulation according to the first sparse code signal, the second sparse code signal, the third sparse code signal, and the fourth sparse code signal to generate a modulated signal;

[0036] S5. Input the modulated signal into a hollow-core optical fiber channel for transmission.

[0037] In some embodiments, step S2 may include:

[0038] For the first data, the second data, the third data, and the fourth data, each data is divided into four resource blocks (subcarriers) occupied by six users according to the factor graph matrix F to perform codebook constellation mapping. Each user carries two bits of data, and each two bits are mapped into a corresponding K-dimensional codeword. , [ . ] T represents a transposition operation; wherein the factor graph matrix F represents the correspondence between multi-user data and multiple resource blocks:

[0039] F = [ 1 1 1 0 1 0 0 0 0 1 1 0 0 1 0 0 0 1 0 1 1 0 1 1 ]

[0040] The rows in the factor graph matrix F represent resource blocks k, k=1, 2, 3, ..., 4; the columns represent users j, j=1, 2, 3, ..., 6; the factor graph matrix F satisfies certain sparsity, where =1 means user j occupies resource block k, corresponding =0 means user j does not occupy the resource block k;

[0041] like Figure 2 As shown in the figure, six users transmit data (1,1), (1,0), (0,1), (0,0), (0,1), (1, 0) respectively. Each user carries two bits of data, and then the codebook constellation is mapped into a corresponding K-dimensional codeword according to the bit data transmitted by the user.

[0042] In some embodiments, Figure 2 As shown, the codebook constellation mapping adopts the constellation mapping in the codebook design library, and the method for obtaining the codebook design library includes:

[0043] Taking the codebook transmission with K=4, J=6, M=4, and N=2 as an example, the overload rate of the transmission system is: λ=J / K =150%, and each user sends the data to be sent every B= bits are mapped into a corresponding K-dimensional codeword X j = [ x j 1 , x j 2 , . . . , x j K ] T , [ . ] T represents the transpose operation, Represents the K-th codeword; K-dimensional codeword Contains N zero elements and the positions of zeros for each user are different;

[0044] The codewords of J users are further superimposed and multiplexed on K empty core subcarriers to form = =4096 different sparse code division technology code words.

[0045] Because of the sparsity of sparse code division technology, the codeword It contains N zero elements and the positions of zeros for each user are different, which improves the distinguishability between users. Each sparse code division technology codeword is first fed into orthogonal space-time block coding modulation to achieve hollow-core optical transmission of multiple independent sparse code division technology layers from different signals.

[0046] from Figure 2 It can be seen that when the total number of resources is 4, each user occupies two resource blocks, and the maximum number of users that the system can accommodate is =6, and on a single resource The number of superimposed users is 3. Taking the uplink sparse code division multiple access system as an example, since data transmitted by multiple users is superimposed on one resource block, the received signal observed by the receiving end at any time is It can be expressed as:

[0047]

[0048] in, is the K-dimensional sparse complex field codeword sent by the j-th user, is the received signal observed by the receiving end, is the channel transmission matrix of user j, n is the additive noise vector, and it obeys the K-dimensional complex Gaussian distribution with zero mean and normalized variance.

[0049] In some embodiments, S3, sparse code division multiplexing the first codebook mapping signal, the second codebook mapping signal, the third codebook mapping signal, and the fourth codebook mapping signal to obtain a first sparse code signal, a second sparse code signal, a third sparse code signal, and a fourth sparse code signal, including:

[0050] According to the traffic requirements of the first codebook mapping signal, the second codebook mapping signal, the third codebook mapping signal, and the fourth codebook mapping signal, sparse codes are reallocated using a user codebook allocation model based on a codebook design library, and a first sparse code signal, a second sparse code signal, a third sparse code signal, and a fourth sparse code signal are generated according to the allocated sparse codes.

[0051] Furthermore, if Figure 3 As shown, the user codebook allocation model includes:

[0052] S31, analyzing the user's traffic demand;

[0053] Different users have different traffic requirements. Some users need high-definition video, which often requires very high bandwidth and consumes a lot of traffic. Some users need ordinary video, which does not require very high traffic. Some users even only need basic voice service communications, which requires the lowest traffic during transmission.

[0054] S32, multi-user codebook allocation method: allocate the codebook system according to the traffic requirements of different users;

[0055] For example, for users who need high-definition video services, the first codebook system is allocated to user 1, because the first codebook carries the most information and has the most traffic transmission; the remaining codebook systems that carry less information are allocated to other users who do not have very high traffic requirements. If more than one user wants high-definition video, in addition to the first codebook system, the remaining two codebook systems can also be allocated to other users with the same needs. This method can also meet the traffic requirements of high-definition video.

[0056] S33, when the user's needs change, release the codebook;

[0057] For example, when user 1 no longer has traffic demand for high-definition video, the first codebook system must be released so that when the needs of other users change, the allocation of the entire codebook system can be quickly adjusted. The advantage of this is that the codebook will not be used by a fixed user, but will be released as the user's traffic demand changes and then allocated to other users with new traffic demands.

[0058] S34, go to S31 to continue the cyclic analysis;

[0059] After the codebook is released, the entire codebook allocation process returns to S31, and codebooks are allocated to different users again according to new user needs. When the needs change, the codebook is released again, and the entire multi-user codebook allocation model cycle process is re-analyzed.

[0060] In some embodiments, S4, performing orthogonal space-time block coding modulation according to the first sparse code signal, the second sparse code signal, the third sparse code signal, and the fourth sparse code signal to generate a modulated signal, including:

[0061] The space-time coding matrix of the orthogonal space-time block coding modulation is defined as a dimensional matrix C, where represents the number of information transmissions, L represents the number of time slots required to transmit a set of modulation constellation symbols. In this application, =L=4;

[0062] The constellation diagram contains symbols, each time encoding is performed, first for each N*b bit group, the modulator selects a constellation symbol for each b bit, and selects a total of N constellation symbols from the constellation diagram , and then these N constellation symbols are generated by the encoder of orthogonal space-time block coding modulation A parallel signal sequence of length L, the parallel signal sequence is The information is transmitted and transmitted using L time slots at the same time;

[0063] For each space-time block, N constellation symbols are transmitted through L time slots, so the code rate of this codeword is defined as R= , represents the average number of modulation constellation symbols transmitted in a unit time slot;

[0064] The space-time coding matrix C of orthogonal space-time block coding modulation is composed of N constellation symbols and their conjugation , composed of, having the following properties:

[0065]

[0066] in is the conjugate of the space-time coding matrix C, is a constant, is a The identity matrix of

[0067] The i-th row element in the space-time coding matrix C represents the symbol sequence sent by the i-th information transmission in L time slots, and the j-th column element in the space-time coding matrix C represents the symbol sequence sent by the i-th information transmission in the j-th time slot. The symbol sequence sent by the information transmission; the element of the i-th row and j-th column in the space-time coding matrix C , represents the symbol sent by the i-th information transmission in the j-th time slot, i=1, 2, ..., , j=1,2,…,T; each row in the space-time coding matrix C is mutually orthogonal;

[0068] c i = [ c i ， 1 ， c i ， 2 ， … ， c i ， L ] is the symbol sequence sent by the i-th information transmission, i=1, 2, ... , is the symbol sequence sent by the t-th information transmission, then the following properties:

[0069] , ,

[0070] in, express and The inner product of express conjugation of;

[0071] In the orthogonal space-time block coded modulation module, the four-dimensional real orthogonal space-time block C 4 The structure is:

[0072] C 4 = [ s 1 − s 2 s 2 s 1 − s 3 − s 4 s 4 − s 3 s 3 − s 4 s 4 s 3 s 1 s 2 − s 2 s 1 ] ,

[0073] The rows of the real orthogonal space-time blocks are mutually orthogonal, and the main diagonal elements are all , and is an antisymmetric matrix; the information transmission number The number of time slots L transmitted is equal to the number of constellation symbols N contained in each space-time block code, that is, =N=L.

[0074] Simulation Example: This example builds a dual polarization multiplexing coherent optical communication transmission system, such as Figure 5 As shown, offline DSP modulation and demodulation are performed in Matlab software. First, a set of binary sequences are generated as raw data, and every 4 bits are mapped into a data symbol. Two sets of external cavity lasers (ECL) are used to generate optical carriers. The offline DSP data is converted from digital to analog by an arbitrary waveform generator (AWG) to form an electrical signal. The two sets of electrical signals are converted from electrical to optical by an IQ modulator to obtain an optical carrier carrying information. The modulated optical signal is passed through a polarization beam splitter (PBS) to obtain two orthogonal X and Y polarization optical signals, which are connected using polarization-maintaining optical fibers to ensure that the polarization state of the optical signal remains unchanged. The polarization beam combiner (PBC) combines the two polarized lights into one, multiplexes them using a wavelength division multiplexer, amplifies them through an EDFA, and sends them into the optical fiber for transmission. At the receiving end, the coherent optical receiver performs homodyne detection on the wavelength division multiplexed optical signal to obtain the baseband electrical signal and capture it using an oscilloscope MSO for offline DSP demodulation processing. The process of the DSP at the receiving end is as follows: First, dispersion compensation is performed on the received signal in the frequency domain; after resampling, clock recovery is performed to eliminate timing errors. Finally, data demodulation and decryption are performed to recover the received binary data and perform a bit error rate test with the original data.

[0075] In order to verify the feasibility of the optical signal method based on sparse orthogonal space-time code multi-dimensional modulation, this application uses MATLAB simulation software to simulate the Gaussian channel of four-way sparse orthogonal space-time code multi-dimensional modulation signal transmission data. In the simulation process, a Gaussian white noise channel is used to obtain a curve of bit error rate versus signal-to-noise ratio, as shown in Figure 6It can be clearly seen that the received bit error rate gradually decreases with the increase of signal-to-noise ratio (SNR), proving that the optical signal generation method of hollow-core optical fiber by combining sparse orthogonal space-time code multi-dimensional modulation is feasible and can improve transmission efficiency, link capacity and reliability.

[0076] Embodiment 2: Based on Embodiment 1, this embodiment provides an optical signal generating device based on sparse orthogonal space-time code multi-dimensional modulation, including a processor and a storage medium;

[0077] The storage medium is used to store instructions;

[0078] The processor is used to operate according to the instruction to execute the method according to embodiment 1.

[0079] Embodiment 3: Based on Embodiment 1, this embodiment provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the method described in Embodiment 1 is implemented.

[0080] Embodiment 4: Based on Embodiment 1, this embodiment provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor implements the method described in Embodiment 1 when executing the computer program.

[0081] Embodiment 5: Based on Embodiment 1, this embodiment provides a computer program product, including a computer program, which implements the method described in Embodiment 1 when executed by a processor.

[0082] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware. Moreover, the present application may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0083] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram and the combination of the processes and / or blocks in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1A device that provides the functions specified in a block or multiple blocks.

[0084] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0085] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0086] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A method for generating an optical signal based on multi-dimensional modulation of sparse orthogonal space-time codes, characterized in that: include: S1. Randomly divide the original data to be sent into first data, second data, third data, and fourth data; S2. Perform codebook constellation mapping on the first data, the second data, the third data, and the fourth data respectively to obtain a first codebook mapping signal, a second codebook mapping signal, a third codebook mapping signal, and a fourth codebook mapping signal; S3, performing sparse code division multiplexing on the first codebook mapping signal, the second codebook mapping signal, the third codebook mapping signal, and the fourth codebook mapping signal to obtain a first sparse code signal, a second sparse code signal, a third sparse code signal, and a fourth sparse code signal; S4, performing orthogonal space-time block coding modulation according to the first sparse code signal, the second sparse code signal, the third sparse code signal, and the fourth sparse code signal to generate a modulated signal; S5. Input the modulated signal into a hollow-core optical fiber channel for transmission.

2. The method according to claim 1, characterized in that Step S2 includes: For the first data, the second data, the third data, and the fourth data, each data is divided into four resource blocks occupied by 6 users according to the factor graph matrix F for codebook constellation mapping, each user carries two bits of data, and each 2 bits are mapped into a corresponding K-dimensional codeword; wherein the factor graph matrix F represents the corresponding relationship between multi-user data and multiple resource blocks: ， The rows in the factor graph matrix F represent resource blocks k, k=1, 2, 3, ..., 4; the columns represent users j, j=1, 2, 3, ..., 6; the factor graph matrix F satisfies certain sparsity, where =1 means user j occupies resource block k, corresponding =0 means that user j does not occupy the resource block k.

3. The method according to claim 1, characterized in that The codebook constellation mapping adopts the constellation mapping in the codebook design library, and the method for obtaining the codebook design library includes: Take the codebook transmission example with K=4, J=6, M=4, and N=2. Each user sends the data to be sent in B= bits are mapped into a corresponding K-dimensional codeword , represents the transpose operation, Represents the K-th dimensional codeword; K-dimensional codeword Contains N zero elements and the positions of zeros for each user are different; The codewords of J users are superimposed and multiplexed on K empty core subcarriers to form = =4096 different sparse code division technology code words.

4. The method according to claim 3, characterized in that S3, performing sparse code division multiplexing on the first codebook mapping signal, the second codebook mapping signal, the third codebook mapping signal, and the fourth codebook mapping signal to obtain a first sparse code signal, a second sparse code signal, a third sparse code signal, and a fourth sparse code signal, including: According to the traffic requirements of the first codebook mapping signal, the second codebook mapping signal, the third codebook mapping signal, and the fourth codebook mapping signal, sparse codes are reallocated using a user codebook allocation model based on a codebook design library, and a first sparse code signal, a second sparse code signal, a third sparse code signal, and a fourth sparse code signal are generated according to the allocated sparse codes.

5. The method according to claim 4, characterized in that The user codebook allocation model includes: S31, analyzing the user's traffic demand; S32, multi-user codebook allocation method: allocate the codebook system according to the traffic requirements of different users; S33, when the user's needs change, release the codebook; S34, go to S31 and continue to analyze the traffic demand in a loop, and allocate codebooks to different users again according to new user demands.

6. The method according to claim 1, characterized in that S4, performing orthogonal space-time block coding modulation according to the first sparse code signal, the second sparse code signal, the third sparse code signal, and the fourth sparse code signal to generate a modulated signal, including: The space-time coding matrix of the orthogonal space-time block coding modulation is defined as a dimensional matrix C, where represents the number of information transmissions, L represents the number of time slots required to transmit a set of modulation constellation symbols, =L=4; The constellation diagram contains symbols, each time encoding is performed, first for each N*b bit group, the modulator selects a constellation symbol for each b bit, and selects a total of N constellation symbols from the constellation diagram , and then these N constellation symbols are generated by the encoder of orthogonal space-time block coding modulation A parallel signal sequence of length L, the parallel signal sequence is The information is transmitted and transmitted using L time slots at the same time; For each space-time block, N constellation symbols are transmitted through L time slots, so the code rate of this codeword is defined as R = , represents the average number of modulation constellation symbols transmitted in a unit time slot; The space-time coding matrix C of orthogonal space-time block coding modulation is composed of N constellation symbols and their conjugation , composed of, having the following properties: ， in is the conjugate of the space-time coding matrix C, is a constant, is a The identity matrix of The i-th row element in the space-time coding matrix C represents the symbol sequence sent by the i-th information transmission in L time slots, and the j-th column element in the space-time coding matrix C represents the symbol sequence sent by the i-th information transmission in the j-th time slot. The symbol sequence sent by the information transmission; the element of the i-th row and j-th column in the space-time coding matrix C , represents the symbol sent by the i-th information transmission in the j-th time slot, i=1, 2, ..., , j=1,2,…,T; each row in the space-time coding matrix C is mutually orthogonal; is the symbol sequence sent by the i-th information transmission, i=1, 2, ... , is the symbol sequence sent by the t-th information transmission, then the following properties: ， 、 ， in, express and The inner product of express conjugation of; In the orthogonal space-time block coding modulation module, the four-dimensional real orthogonal space-time block C4 structure is: ， The rows of the real orthogonal space-time blocks are mutually orthogonal, and the main diagonal elements are all , and is an antisymmetric matrix; the information transmission number The number of time slots L transmitted is equal to the number of constellation symbols N contained in each space-time block code, that is, =N=L.

7. An optical signal generating device based on sparse orthogonal space-time code multi-dimensional modulation, characterized in that: including processor and storage medium; The storage medium is used to store instructions; The processor is configured to operate according to the instructions to execute the method according to any one of claims 1 to 6.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the method according to any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

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