A signal rate splitting transmission method and receiving method suitable for optical fiber communication

Abstract

The application discloses a signal rate splitting transmission method and receiving method suitable for optical fiber communication, and belongs to the technical field of communication. The transmission method comprises the following steps: decomposing the information of each user into public information and private information, combining the public information of all users into a public data stream, taking the private information of each user as a private data stream, and then performing serial-parallel conversion and constellation mapping to obtain a public information constellation point and a private information constellation point of each user; loading the public information constellation point onto a first group of subcarriers, loading the private information constellation point of each user onto a second group of subcarriers whose order is disturbed by a chaotic key, assigning the public information constellation point a first power, assigning the private information constellation point a second power smaller than the first power, and superimposing to form an RSMA signal. The application solves the problem that the existing optical fiber communication system cannot utilize multiple antennas to perform layered secure transmission.

Description

TECHNICAL FIELD

[0001] The present application relates to a signal rate splitting transmission method and receiving method suitable for optical fiber communication, belonging to the field of communication technology. BACKGROUND

[0002] With the continuous development of communication networks, the technical demands of network equipment, artificial intelligence services and new applications are growing, bringing higher challenges to the performance of communication systems. These challenges involve improving spectral efficiency, improving energy utilization, expanding signal coverage, achieving high reliability transmission, ensuring fairness between users, and optimizing overall service quality. To address these challenges, researchers are exploring new network architectures and advanced transmission technologies. In the current 6G network research, the signal rate splitting transmission method (RSMA, Rate-Splitting Multiple Access) is attracting attention due to its excellent interference management capability. RSMA splits user information into public information and private information, allowing multiple users to more efficiently share wireless resources. RSMA improves system spectral efficiency, improves communication robustness, and improves multi-user communication fairness. RSMA is considered one of the key technologies for future wireless communication systems.

[0003] However, there is not much research on RSMA in the field of optical fiber communication. This is mainly because the channel conditions of optical fiber communication and wireless communication are quite different. Wireless communication systems have high channel degrees of freedom and can transmit split information using multiple antennas. Optical fiber communication channel structure is single and difficult to directly apply the splitting transmission mechanism of RSMA. In wireless communication, public information transmission can use unified encoding. Private information of different users is encoded independently to ensure that each user can only decode their own private information and cannot obtain the private information of other users. Therefore, the existing optical fiber communication system cannot use multiple antennas for hierarchical secure transmission. SUMMARY

[0004] The purpose of the present application is to provide a signal rate splitting transmission method and receiving method suitable for optical fiber communication, which compensates for the deficiency of optical fiber communication in multi-user information splitting transmission through OFDM (Orthogonal Frequency-Division Multiplexing) technology, and improves the security of private information by combining a chaotic system, to solve the problem that the existing optical fiber communication system cannot use multiple antennas for hierarchical secure transmission.

[0005] To solve the above technical problems, the present application is implemented by using the following technical solutions.

[0006] In a first aspect, the present application provides a signal rate splitting transmission method suitable for optical fiber communication, executed by an optical fiber channel sending end, comprising:

[0007] obtaining information of a plurality of users;

[0008] decomposing the information of each user into common information and private information according to a channel condition;

[0009] combining the common information of all users into a common data stream;

[0010] separately taking the private information of each user as a private data stream;

[0011] performing serial-parallel conversion and constellation mapping through Gray coding on the common data stream and the private data stream to obtain a common information constellation point and a private information constellation point of each user;

[0012] loading the common information constellation point onto a first group of subcarriers;

[0013] generating a chaotic key for each user by using a chaotic system and loading the private information constellation point of each user onto a second group of subcarriers in a sequence disturbed by the chaotic key;

[0014] performing inverse fast Fourier transform and parallel-serial conversion on the common information constellation point on the first group of subcarriers and the private information constellation point on the second group of subcarriers;

[0015] allocating a first power to the common information constellation point after parallel-serial conversion to obtain common information of all users;

[0016] allocating a second power smaller than the first power to the private information constellation point after parallel-serial conversion to obtain private information of all users;

[0017] superimposing the common information of all users and the private information of all users through superposition coding to form an RSMA signal and transmitting the RSMA signal to an optical fiber channel.

[0018] Further, decomposing the information of each user into common information and private information according to a channel condition comprises:

[0019] if the bit error rate is less than a first preset threshold, the number of private information of the decomposed user is greater than the number of common information;

[0020] if the bit error rate is greater than or equal to the first preset threshold, the number of private information of the decomposed user is less than the number of common information;

[0021] wherein the sum of the number of private information of all users is equal to the sum of the number of common information of all users.

[0022] Furthermore, after performing inverse fast Fourier transform and parallel-to-serial conversion on the public information constellation points on the first set of subcarriers and the private information constellation points on the second set of subcarriers, the method further includes adding a cyclic prefix / suffix to the public information constellation points and private information constellation points after the parallel-to-serial conversion.

[0023] Furthermore, the public information and private information of all users are respectively represented as follows:

[0024] ;

[0025] ;

[0026] In the formula, Indicates the current time Public information of all users Indicates the first Common information constellation points modulated on each subcarrier, Indicates public information. Represents the base of natural numbers. Represents the imaginary unit. Indicates the current time No. The frequency of each subcarrier This represents a sequence of public information mapping indexes for all users. Indicates the current time. All users' private information Indicates private information. Indicates the first The first user's private information constellation point modulated on each subcarrier. Indicates the first The private information constellation points of the second user modulated on each subcarrier, Indicates the first The modulation on the nth subcarrier Each user's private information constellation points This represents the first user's private information mapping index sequence. This represents the private information mapping index sequence of the second user. Indicates the first A sequence of private information mapping indexes for each user.

[0027] Furthermore, the RSMA signal is represented as:

[0028] ;

[0029] In the formula, Indicates RSMA signal, Indicates the first power. represents the second power.

[0030] Further, a chaotic key is generated for each user using a chaotic system, and the private information constellation points of each user are loaded onto a second group of subcarriers in a scrambled order using the chaotic key, including:

[0031] The m subcarriers are divided into m / n groups, where n represents the number of users;

[0032] The zth, n+zth, …, m-n+zth subcarriers are combined into the zth subcarrier group, which is assigned to the private information constellation points of the zth user, where 1≤z≤n, and the number of subcarriers assigned to each user is the same as the number of private information constellation points of each user;

[0033] The initial value of the zth user is received as input using a Tent / Logistic chaotic system and iterated to generate the zth chaotic sequence, which is sorted by size to generate the mapping index sequence of the zth user, and the order of the subcarriers in the zth subcarrier group is scrambled based on the mapping index sequence of the zth user, and the private information constellation points of the zth user are mapped onto the zth subcarrier group in the scrambled order, where the number of iterations is the same as the number of subcarriers in the zth subcarrier group.

[0034] Further, if only two users' information is obtained, a chaotic key is generated for each user using a chaotic system, and the private information constellation points of each user are loaded onto a second group of subcarriers in a scrambled order using the chaotic key, including:

[0035] The odd-numbered subcarriers are assigned to the private information constellation points of user 1, and the even-numbered subcarriers are assigned to the private information constellation points of user 2, where the number of odd-numbered subcarriers and even-numbered subcarriers is the same as the number of all private information constellation points;

[0036] The initial value of user 1 is received as input using a Tent chaotic system and iterated to generate the first chaotic sequence, which is sorted by size to generate the first mapping index sequence, and the order of the odd-numbered subcarriers is scrambled based on the first mapping index sequence, and the private information constellation points of user 1 are mapped onto the odd-numbered subcarriers in the scrambled order, where the number of iterations is the same as the number of odd-numbered subcarriers;

[0037] The initial value of user 2 is received as input using a Logistic chaotic system and iterated to generate the second chaotic sequence, which is sorted by size to generate the second mapping index sequence, and the order of the even-numbered subcarriers is scrambled based on the second mapping index sequence, and the private information constellation points of user 2 are mapped onto the even-numbered subcarriers in the scrambled order, where the number of iterations is the same as the number of even-numbered subcarriers.

[0038] In a second aspect, the present application provides a signal rate split receiving method suitable for optical fiber communication, which is executed by an optical fiber channel receiving end and comprises the following steps:

[0039] receiving an RSMA signal;

[0040] performing channel estimation on the RSMA signal to obtain first channel information;

[0041] performing channel zero-forcing equalization on the first channel information to obtain first channel information after channel equalization;

[0042] performing demodulation on the first channel information after channel equalization to obtain common information of all users;

[0043] obtaining common information of a target user from the common information of all users;

[0044] re-modulating the common information of all users, subtracting the re-modulated common information of all users from the RSMA signal, and performing channel estimation to obtain second channel information;

[0045] performing channel zero-forcing equalization on the second channel information to obtain second channel information after channel equalization;

[0046] performing demodulation on the second channel information after channel equalization to obtain private information of all users;

[0047] generating a chaotic key for each user by using a chaotic system, and obtaining private information of each user from the private information of all users;

[0048] obtaining information of each user by superimposing the common information and the private information of each user;

[0049] wherein the chaotic key of a user is the same as a chaotic key generated by the user at an optical fiber channel sending end;

[0050] The RSMA signal is an RSMA signal transmitted by the signal rate split transmission method suitable for optical fiber communication according to any one of the first aspect.

[0051] Further, the demodulation on the first channel information after channel equalization to obtain common information of all users comprises the following steps:

[0052] performing serial-parallel conversion on the received RSMA signal to obtain an RSMA time domain signal matrix;

[0053] If the optical fiber signal sending end adds a cyclic prefix / suffix to the common information constellation point and the private information constellation point after serial-parallel conversion, then the RSMA time domain signal matrix is removed of the cyclic prefix / suffix and then subjected to fast Fourier transform to obtain an RSMA frequency domain signal containing the common information and the private information.

[0054] Otherwise, directly perform fast Fourier transform to obtain the RSMA frequency domain signal containing the public information and the private information;

[0055] According to the public information mapping index sequence of all users of the optical fiber signal sending end, superimposed information of the public information of all users and the private information of all users is extracted from the RSMA frequency domain signal containing the public information and the private information;

[0056] The superimposed information of the public information of all users and the private information of all users is divided by the first channel information to obtain the superimposed information of the public information of all users and the private information of all users after equalization;

[0057] The private information of all users is used as interference, and the superimposed information of the public information of all users and the private information of all users after equalization is divided by to obtain the public information constellation point of all users;

[0058] The public information constellation point of all users is demapped to obtain the public information of all users;

[0059] Among them, indicates the first power allocated to the public information constellation point after parallel-serial conversion of the optical fiber channel sending end.

[0060] Further, according to the second channel information after channel equalization, the private information of all users is demodulated, including:

[0061] The public information of all users is re-modulated to obtain the re-modulated public information of all users;

[0062] According to the private information mapping index sequence of all users of the optical fiber signal sending end, superimposed information of the public information of all users and the private information of all users is extracted from the RSMA frequency domain signal containing the public information and the private information;

[0063] The superimposed information of the public information of all users and the private information of all users is subtracted from the re-modulated public information of all users to obtain the private information of all users without equalization;

[0064] The private information of all users is divided by the first channel information to obtain the private information of all users after equalization;

[0065] The private information of all users after equalization is divided by to obtain the private information constellation point of all users;

[0066] The private information constellation point of all users is demapped to obtain the private information of all users;

[0067] wherein, P2 represents the second power allocated by the optical channel transmitting end to the private information constellation point after parallel-serial conversion.

[0068] Compared with the prior art, the present application has the following beneficial effects:

[0069] 1. The signal rate splitting transmission method for optical fiber communication provided by the present application, by splitting the user information into public data stream and private data stream at the optical channel transmitting end and loading them into subcarrier groups respectively, and by using power domain superposition coding technology, the frequency spectrum efficiency and the anti-interference ability are synergistically improved, wherein the chaotic key dynamically scrambles the subcarrier sequence of the private data stream, effectively suppressing the constellation point distortion caused by the nonlinear effect in the optical channel, and by differentiating the power allocation of public information and private information, the data confidentiality in the multi-user access scenario is significantly enhanced under the premise of ensuring the reliability of basic transmission, solving the problem that the existing optical fiber communication system cannot use multiple antennas for hierarchical secure transmission.

[0070] 2. The signal rate splitting reception method for optical fiber communication provided by the present application, by iteratively executing channel equalization and interference cancellation mechanism at the optical channel receiving end, the public information of all users is extracted and reconstructed in the demodulation stage, and then the private information of all users is separated out by subtracting the reconstructed public information from the RSMA signal, and the private information of each user is decrypted in combination with the chaotic key synchronized with the transmitting end, effectively suppressing the multi-user interference, wherein the mechanism of dynamically adjusting the equalization parameters based on the channel evaluation results significantly improves the demodulation sensitivity in weak signal environment, and at the same time, the calculation complexity is reduced through the phased demodulation architecture, ensuring the reception reliability of high-order modulation signals in the optical channel. BRIEF DESCRIPTION OF DRAWINGS

[0071] Figure 1 is a whole process schematic diagram of the signal rate splitting transmission method and reception method for optical fiber communication provided by the embodiment of the present application;

[0072] Figure 2 is a chaotic key driven subcarrier arrangement schematic diagram provided by the embodiment of the present application;

[0073] Figure 3 is a process schematic diagram of loading the private information constellation point of each user to the second group of subcarriers whose order is disturbed by the chaotic key, wherein Figure 3 (a) in the above figure (a) represents a process schematic diagram of loading the private information constellation point of user 1 to the odd subcarriers whose order is disturbed by the chaotic key, Figure 3 (b) in the above figure (b) represents a process schematic diagram of loading the private information constellation point of user 1 to the even subcarriers whose order is disturbed by the chaotic key.

[0074] Figure 4 is a schematic diagram of information transmission of a user provided by an embodiment of the present application. DETAILED DESCRIPTION

[0075] The technical solutions of the present application will be described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific features in the embodiments and the specific embodiments are detailed descriptions of the technical solutions of the present application, and are not limitations of the technical solutions of the present application. In the case of no conflict, the technical features in the embodiments and the specific embodiments can be combined with each other.

[0076] The term "and / or", only describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " generally represents that the associated objects before and after are in an "or" relationship.

[0077] Embodiment 1

[0078] This embodiment introduces a signal rate splitting transmission method suitable for optical fiber communication, characterized by being executed by an optical fiber channel sending end, comprising:

[0079] Step one: obtaining information of a plurality of users.

[0080] The present application establishes a complete data source basis through a multi-user information acquisition mechanism, provides original data support for subsequent channel adaptive splitting, ensures that the subsequent processing process has complete information dimension, and avoids transmission performance bottlenecks caused by data loss.

[0081] Step two: according to the channel condition, the information of each user is split into public information and private information.

[0082] The present application splits the information of each user into public information and private information according to the channel condition, which not only meets the reliability requirements of basic coverage, but also provides flexible resource allocation space for differentiated services, and realizes the collaborative optimization of channel capacity and transmission quality.

[0083] Step three: combine the public information of all users into a public data stream.

[0084] The present application reduces the redundancy overhead through data aggregation through the public information merging mechanism, forms a unified efficient transmission baseband, reduces the occupation of subcarrier resources, improves the spectrum utilization rate, and at the same time provides centralized processing advantages for subsequent public channel coding.

[0085] Step four: each user's private information is separately taken as a private data stream.

[0086] The application ensures user data isolation by private information independent stream design, avoids multi-user interference by special resource allocation, provides physical layer protection for personalized services such as secret communication, and enhances the adaptation ability of the system to differentiated service requirements.

[0087] Step five: serial-parallel conversion is performed on the public data stream and the private data stream, and constellation mapping is performed through Gray coding to obtain a public information constellation point and a private information constellation point of each user.

[0088] The application reduces inter-symbol interference while maintaining data rate through serial-parallel conversion combined with Gray coding constellation mapping, and the Gray coding feature allows only one bit difference between adjacent constellation points, significantly reduces the bit error rate caused by fiber nonlinear effects, and improves mapping efficiency and transmission robustness.

[0089] Step six: the public information constellation point is loaded onto the first group of subcarriers.

[0090] The application loads public information to the first group of subcarriers first to build a basic transmission layer, enhances anti-fading ability by using the frequency diversity characteristics of subcarrier clusters, ensures reliable transmission of public control signals and low-priority services, and forms a stable channel reference.

[0091] Step seven: a chaotic key of each user is generated using a chaotic system, and the private information constellation point of each user is loaded onto the second group of subcarriers whose order is scrambled by the chaotic key.

[0092] The application uses a subcarrier order encryption mechanism driven by a chaotic key to generate a pseudo-random sequence through nonlinear dynamic characteristics, break the fixed mapping pattern of subcarriers, effectively suppress eavesdropping attacks and illegal access, and at the same time, the initial value sensitivity of the chaotic system ensures the security of key distribution.

[0093] Step eight: inverse fast Fourier transform and serial-parallel conversion are performed on the public information constellation point on the first group of subcarriers and the private information constellation point on the second group of subcarriers.

[0094] The application realizes conversion from frequency domain to time domain based on inverse fast Fourier transform, combines serial-parallel conversion to compress transmission delay, reduces inter-symbol interference through multi-carrier parallel transmission, improves the carrying capacity of fiber channel for high-speed signals, and meets the anti-multipath interference characteristics of OFDM technology.

[0095] Step nine: the first power is allocated to the public information constellation point after serial-parallel conversion to obtain the public information of all users.

[0096] The application ensures the signal penetration capability of the basic coverage layer through a public information high-power allocation strategy, improves the demodulation signal-to-noise ratio at the receiving end through power redundancy design, and meets the reliability requirements of basic services.

[0097] Step ten: assigning a second power less than the first power to the power value of the parallel-serial converted private information constellation point to obtain the private information of all users.

[0098] The present application reduces the interference between users under the premise of ensuring the demodulation threshold through the low-power design of the private signal, improves the total capacity of the system through power domain multiplexing, reduces energy consumption, conforms to the green communication concept, and realizes the balance between high efficiency and low power consumption.

[0099] Step eleven: superimposing all user public information and all user private information through superposition coding to form an RSMA signal and transmitting the RSMA signal to the optical fiber channel.

[0100] The present application realizes multi-stream multiplexing through superposition coding to form an RSMA signal, constructs a virtual multiple access channel in a single physical channel through the joint design of the power domain and the code domain, improves the multi-user access capability of the optical fiber link, dynamically adapts to business traffic fluctuations, and maximizes the channel utilization rate.

[0101] Embodiment 2

[0102] Based on the same inventive concept as embodiment 1, the present embodiment introduces a signal rate split reception method suitable for optical fiber communication, comprising:

[0103] Step one: receiving an RSMA signal.

[0104] In the present embodiment, the RSMA signal is the RSMA signal transmitted by the signal rate split transmission method suitable for optical fiber communication described in embodiment 1.

[0105] The present application completes the initial capture of the RSMA signal through the wideband receiver mechanism, establishes the reception baseband of the multi-user mixed signal, provides complete time domain sampling data for subsequent channel decoding, ensures the continuity of the signal processing process, and avoids demodulation failure caused by incomplete reception.

[0106] Step two: obtaining first channel information according to channel evaluation of the RSMA signal.

[0107] The first channel information obtained by the present application according to the channel evaluation of the RSMA signal provides a dynamic adjustment basis for equalizer parameter configuration, and improves the spatial and temporal resolution of channel state perception.

[0108] Step three: performing channel zero-forcing equalization according to the first channel information to obtain the first channel information after channel equalization.

[0109] The present application performs channel zero-forcing equalization according to the first channel information to obtain the first channel information after channel equalization, effectively compensates for the inter-symbol interference caused by mode coupling effects in the optical fiber channel, effectively reduces the symbol error rate of the first channel information after channel equalization, and guarantees the demodulation reliability of the public information.

[0110] Step four: demodulating according to the first channel information after channel equalization to obtain the public information of all users.

[0111] The application demodulates according to the first channel information after channel equalization to obtain the public information of all users, realizes the synchronous recovery of the multi-user public control signal and the basic service data, and improves the demodulation efficiency.

[0112] Step five: obtaining the public information of the target user from the public information of all users.

[0113] The application obtains the public information of the target user from the public information of all users, avoids full data traversal, and improves the user-level data extraction efficiency

[0114] Step six: re-modulating the public information of all users, subtracting the re-modulated public information of all users from the RSMA signal, and then performing channel evaluation to obtain the second channel information.

[0115] The application realizes the power domain separation of the public information and the private information by reconstructing the public information and performing RSMA signal subtraction operation, and obtains the second channel information through channel evaluation, which improves the private signal component signal-to-noise ratio in the second channel information and creates favorable conditions for subsequent private information demodulation.

[0116] Step seven: performing channel zero-forcing equalization according to the second channel information to obtain the second channel information after channel equalization.

[0117] The application performs channel zero-forcing equalization according to the second channel information to obtain the second channel information after channel equalization, which significantly suppresses the nonlinear distortion caused by the Kerr effect of the optical fiber.

[0118] Step eight: demodulating according to the second channel information after channel equalization to obtain the private information of all users.

[0119] Step nine: generating a chaotic key for each user by using a chaotic system, and obtaining the private information of each user from the private information of all users, wherein the chaotic key of the user is the same as the chaotic key generated by the user at the sending end of the optical fiber channel.

[0120] The application generates a chaotic key sequence completely synchronized with the sending end through the chaotic system initial value sharing mechanism, realizes the reverse decryption of the private information subcarrier sequence, and ensures the non-interceptability of the physical layer data transmission.

[0121] Step ten: obtaining the information of each user by superimposing the public information and the private information of each user.

[0122] The application adopts reverse operation of power domain superposition coding, aligns and superimposes public information and private information of each user in time domain, realizes lossless reconstruction of complete information of the user through iterative decoding mechanism, and improves the total throughput of the system compared with single layer transmission.

[0123] Embodiment 3

[0124] The embodiment is directed to the challenge of optical fiber communication in the application of RSMA, combines orthogonal frequency division multiplexing (OFDM) technology, solves the problem that the existing optical fiber communication system cannot utilize multiple antennas for layered secure transmission, OFDM is an efficient multicarrier modulation technology, data can be divided into multiple orthogonal subcarriers and transmitted in parallel, which can improve the system spectrum utilization, in addition, in order to meet the requirement that in the RSMA technology, each user can only decode its own private information and all public information, and cannot decode the private information of other users, the embodiment also introduces chaotic system driven subcarrier selection for information encryption processing, and combines the chaotic system to improve the security of private information. The embodiment can improve the spectrum efficiency and system robustness of optical fiber communication, also provides a new technical direction for future efficient, low interference and multi-user optical fiber communication system, and improves the spectrum efficiency, security and fairness of user information.

[0125] Based on the same inventive concept as other embodiments, the embodiment introduces an implementation step of a signal rate splitting transmission method and receiving method suitable for optical fiber communication, as shown in Figure 1 、 Figure 4 , including:

[0126] Step 1: obtaining information of user 1 and user 2 at the optical fiber channel sending end respectively.

[0127] Step 2: according to the channel condition, the information of each user is split into public information and private information.

[0128] In the embodiment, according to the channel condition, the information of each user is split into public information and private information, including:

[0129] If the error rate is less than the first preset threshold, the number of private information of the split user is greater than the number of public information;

[0130] If the error rate is greater than or equal to the first preset threshold, the number of private information of the split user is less than the number of public information;

[0131] Wherein, the sum of the number of private information of all users is equal to the sum of the number of public information of all users.

[0132] In the embodiment, according to the channel condition, the information of each user is split into public information and private information, and the public information W c,1 and the private information W p,1and the public information W of user 2 c,2 and the private information W of user 2 p,2 .

[0133] Step 3: merge the public information of user 1 and user 2 into a public data stream W c .

[0134] Step 4: separately take the private information of user 1 and user 2 as a private data stream.

[0135] Step 5: perform serial-parallel conversion on the public data stream W c and the private data streams of user 1 and user 2, and perform constellation mapping through Gray coding to obtain a public information constellation point and a private information constellation point of each user.

[0136] In this embodiment, the public data stream W c and the private data streams of user 1 and user 2 after serial-parallel conversion are modulated by 16QAM, and when the number of subcarriers is 1024, the public data stream W c and the private data streams of user 1 and user 2 after 16QAM modulation are arranged in groups of 4 bits and subjected to constellation mapping through Gray coding to obtain a public information constellation point and a private information constellation point of user 1 and a private information constellation point of user 2.

[0137] Step 6: load the public information constellation point onto the first group of subcarriers.

[0138] In this embodiment, 1024 groups of public information constellation points are taken out and loaded onto the first group of subcarriers.

[0139] Step 7: generate a chaotic key for each user by using a chaotic system, and load the private information constellation point of each user onto the second group of subcarriers whose order is disturbed by the chaotic key.

[0140] A chaotic system is a typical nonlinear dynamic system, the evolution trajectory of which is controlled by a deterministic equation. However, the extreme sensitivity to initial conditions makes its behavior exhibit a random-like characteristic, making it difficult for an external observer to predict its long-term state. Chaotic systems have wide applications in fields such as encrypted communication and multiple access. The subcarrier allocation scheme based on a chaotic system has low computational complexity and strong anti-eavesdropping and anti-interference capabilities. Moreover, because of the ergodicity and pseudo-randomness of chaotic systems, this method can effectively protect data security without affecting system throughput.

[0141] In some embodiments, generating a chaotic key for each user by using a chaotic system, and loading the private information constellation point of each user onto the second group of subcarriers whose order is disturbed by the chaotic key, comprises:

[0142] m subcarriers are divided into m / n groups, wherein n represents the number of users;

[0143] The zth, n+zth, …, m-n+zth subcarrier groups are combined into the zth subcarrier group, which is allocated to the private information constellation point of the zth user, wherein 1≤z≤n, and the number of subcarriers allocated to each user is the same as the number of private information constellation points of each user;

[0144] The initial value of the zth user is received as input by a Tent / Logistic chaotic system, and the zth chaotic sequence is generated by iteration, and the zth mapping index sequence is generated by size sorting, and the subcarrier order in the zth subcarrier group is disturbed based on the zth mapping index sequence, and the private information constellation point of the zth user is mapped on the zth subcarrier group in the disturbed order, wherein the number of iterations is the same as the number of subcarriers in the zth subcarrier group.

[0145] To ensure that each user can only decode his own private information and cannot decode the private information of other users, the embodiment takes the two-user communication scenario shown in Figure 2 as an example, and uses two independent chaotic systems to control the allocation of the private information of the two users on the subcarriers, so as to ensure that each user can only decode his own information and cannot obtain the information of other users.

[0146] In the embodiment, chaotic keys of user 1 and user 2 are generated by chaotic systems, and 512 groups are taken out from the private information constellation points of user 1 and user 2 respectively and loaded on the second group of subcarriers whose order is disturbed by the chaotic keys, as shown in Figure 3 , which includes:

[0147] The odd subcarriers are allocated to the private information constellation points of user 1, and the even subcarriers are allocated to the private information constellation points of user 2, wherein the number of odd subcarriers and even subcarriers is the same as the number of all private information constellation points;

[0148] The initial value of user 1 is received as input by a Tent chaotic system, and the first chaotic sequence is generated by iteration, and the first mapping index sequence is generated by size sorting, and the order of the odd subcarriers is disturbed based on the first mapping index sequence, and the private information constellation points of user 1 are mapped on the odd subcarriers in the disturbed order, as shown in Figure 3 (a) of (b), the coordinates (3, 1) are mapped to the 120th odd subcarrier, and the coordinates (-3, 1) are mapped to the 431st odd subcarrier, wherein the number of iterations is the same as the number of odd subcarriers;

[0149] The initial value of user 2 is taken as input of the Logistic chaotic system to generate a second chaotic sequence by iteration, and a second mapping index sequence is generated by sorting the second chaotic sequence in size, and the order of the even subcarriers is disturbed based on the second mapping index sequence, and the private information constellation point of user 2 is mapped on the even subcarriers in the disturbed order, as shown in (b) of Figure 3 The coordinate (-1, -1) is mapped to the 210th even subcarrier, and the coordinate (3, -1) is mapped to the 488th even subcarrier, as shown in (b) of

[0150] Step 8: Inverse fast Fourier transform and parallel-to-serial conversion are performed on the public information constellation points on the first group of subcarriers and the private information constellation points on the second group of subcarriers.

[0151] After the inverse fast Fourier transform and parallel-to-serial conversion are performed on the public information constellation points on the first group of subcarriers and the private information constellation points on the second group of subcarriers, the embodiment further includes adding a cyclic prefix / suffix to the public information constellation points and the private information constellation points after parallel-to-serial conversion to prevent inter-symbol interference and maintain subcarrier orthogonality to avoid inter-carrier interference.

[0152] Step 9: The first power is assigned to the public information constellation points after parallel-to-serial conversion to obtain the public information of all users.

[0153] Step 10: The second power smaller than the first power is assigned to the private information constellation points after parallel-to-serial conversion to obtain the private information of all users.

[0154] In the embodiment, the public information of all users and the private information of all users are respectively represented as:

[0155] ;

[0156] ;

[0157] In the formula, represents the public information of all users at the current time , represents the public information constellation point modulated on the th subcarrier, represents the public information, represents the natural number base, represents the imaginary unit, represents the frequency of the th subcarrier at the current time , represents the public information mapping index sequence of all users, represents the private information of all users at the current time , represents private information of a first user, represents a first user's private information constellation point modulated on the represents a second user's private information constellation point modulated on the represents a first user's private information constellation point modulated on the represents a second user's private information constellation point modulated on the represents a first user's private information mapping index sequence, represents a second user's private information mapping index sequence, represents a first user's private information mapping index sequence.

[0158] Step 11: At the optical channel receiving end, superimpose the public information of all users and the private information of all users by superimposed coding to form an RSMA signal and transmit the RSMA signal to the optical channel.

[0159] In this embodiment, the RSMA signal is represented as:

[0160] ;

[0161] In the formula, represents the RSMA signal, represents a first power, represents a second power.

[0162] Step 12: Receive the RSMA signal.

[0163] Step 13: Obtain first channel information according to channel estimation of the RSMA signal.

[0164] Step 14: Obtain first channel information after channel equalization according to channel zero-forcing equalization of the first channel information.

[0165] Step 15: Obtain public information of all users according to demodulation of the first channel information after channel equalization.

[0166] In this embodiment, the public information of all users is obtained according to demodulation of the first channel information after channel equalization, including:

[0167] Perform serial-parallel conversion on the received RSMA signal to obtain an RSMA time domain signal matrix;

[0168] ​​​​If the optical fiber signal sending end adds cyclic prefix / suffix to the public information constellation point and the private information constellation point after parallel-serial conversion, the RSMA time domain signal matrix is removed from the cyclic prefix / suffix and then fast Fourier transform is performed to obtain the RSMA frequency domain signal containing public information and private information;

[0169] Otherwise, fast Fourier transform is directly performed to obtain the RSMA frequency domain signal containing public information and private information.

[0170] According to the public information mapping index sequence of all users of the optical fiber signal sending end, the superimposed information of the public information of all users and the private information of all users is extracted from the RSMA frequency domain signal containing public information and private information.

[0171] The superimposed information of the public information of all users and the private information of all users after equalization is obtained by dividing the superimposed information of the public information of all users and the private information of all users by the first channel information.

[0172] The private information of all users is used as interference, and the public information constellation point of all users is obtained by dividing the superimposed information of the public information of all users and the private information of all users after equalization by .

[0173] The public information of all users is obtained by demapping the public information constellation point of all users.

[0174] Wherein represents the first power allocated to the public information constellation point after parallel-serial conversion by the optical fiber channel sending end.

[0175] Step 16: Obtain the public information of the target user from the public information of all users.

[0176] Step 17: Remodulate the public information of all users, subtract the remodulated public information of all users from the RSMA signal, and perform channel estimation to obtain the second channel information.

[0177] Step 18: Perform channel zero-forcing equalization according to the second channel information to obtain the second channel information after channel equalization.

[0178] Step 19: Demodulate according to the second channel information after channel equalization to obtain the private information of all users.

[0179] In this embodiment, demodulation is performed according to the second channel information after channel equalization to obtain the private information of all users, including:

[0180] The public information of all users is remodulated to obtain the remodulated public information of all users.

[0181] According to the private information mapping index sequence of all users of the optical fiber signal sending end, superimposed information of the public information of all users and the private information of all users is extracted from the RSMA frequency domain signal containing the public information and the private information.

[0182] The superimposed information of the public information of all users and the private information of all users is subtracted by the remodulated public information of all users to obtain the unbalanced private information of all users.

[0183] The unbalanced private information of all users is divided by the first channel information to obtain the balanced private information of all users.

[0184] The balanced private information of all users is divided by to obtain the private information constellation point of all users.

[0185] The private information constellation point of all users is demapped to obtain the private information of all users.

[0186] Wherein represents the second power allocated to the private information constellation point after parallel-serial conversion of the optical fiber channel sending end.

[0187] Step 20: A chaos key of each user is generated by using a chaos system, and the private information of each user is obtained from the private information of all users, wherein the chaos key of the user is the same as the chaos key generated by the user at the optical fiber channel sending end.

[0188] As shown in Figure 4 , in the optical fiber channel receiving end, each user can only decode its own private information by using its own corresponding chaos key, and due to the lack of the chaos key of another user, it cannot decode the information of other users, which not only meets the basic requirements of RSMA, but also effectively enhances the security of the system and prevents data eavesdropping and cross-user interference.

[0189] Step 21: The information of each user is obtained by superimposing the public information and the private information of each user.

[0190] In summary of the above embodiments, the signal rate splitting transmission method suitable for optical fiber communication provided by the present application splits user information into public data stream and private data stream at the optical fiber channel sending end and loads them into subcarrier groups respectively, and simultaneously uses power domain superposition coding technology to realize the synergistic improvement of spectral efficiency and anti-interference capability, wherein the chaotic key dynamically scrambles the subcarrier sequence of the private data stream, effectively inhibiting the constellation point distortion caused by the nonlinear effect in the optical fiber channel, and through the differential allocation of the power of public information and private information, the data confidentiality in the multi-user access scenario is significantly enhanced on the premise of ensuring the reliability of basic transmission, solving the problem that the existing optical fiber communication system cannot use multiple antennas for hierarchical secure transmission.

[0191] The signal rate splitting receiving method suitable for optical fiber communication provided by the present application iteratively executes channel equalization and interference cancellation mechanism at the optical fiber channel receiving end, extracts and reconstructs the public information of all users in the demodulation stage, and then separates the private information of all users by subtracting the reconstructed public information from the RSMA signal, and decrypts the private information of each user by combining the chaotic key synchronized with the sending end, thereby realizing effective suppression of multi-user interference, wherein the mechanism of dynamically adjusting the equalization parameters based on the channel evaluation results significantly improves the demodulation sensitivity in a weak signal environment, and at the same time, the phased demodulation architecture reduces the computational complexity, ensuring the reception reliability of high-order modulation signals in the optical fiber channel. The present application realizes the technical requirements of the RSMA system in the optical fiber OFDM communication through chaotic system driven subcarrier selection.

[0192] Those skilled in the art will appreciate that embodiments of the present application can be provided as methods, systems, or computer program products. Accordingly, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application can 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-ROMs, optical storage media, etc.) having computer usable program code embodied therein.

[0193] The present application is described with reference to flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as combinations of flows and / or blocks in the flowcharts and / or block diagrams, 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 apparatus to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing apparatus produce a device that implements the flowcharts and / or block diagrams. Figure 1 one flow or multiple flows and / or blocks Figure 1means for performing the function specified by the block or blocks.

[0194] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the flow Figure 1 flow or flows and / or blocks Figure 1 means for performing the function specified by the block or blocks.

[0195] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the flow Figure 1 flow or flows and / or blocks Figure 1 means for performing the function specified by the block or blocks.

[0196] The embodiments of the present application described above are merely exemplary and are not intended to limit the present application to the above-described embodiments, but rather the above-described embodiments are merely illustrative of the present application. Therefore, various modifications can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications are intended to be within the scope of the present application.

Claims

1. A signal rate splitting and transmission method suitable for optical fiber communication, characterized in that, Performed by the fiber optic channel transmitter, including: Obtain information from several users; Based on channel conditions, each user's information is broken down into public and private information, including: If the bit error rate is less than the first preset threshold, then the number of private information items of the user that are disassembled is greater than the number of public information items. If the bit error rate is greater than or equal to the first preset threshold, then the number of private information items of the user that are disassembled is less than the number of public information items. Among them, the sum of the number of private information items of all users is equal to the sum of the number of public information items of all users; Merge all users' public information into a public data stream; Each user's private information is treated as a separate private data stream; The public and private data streams are converted from serial to parallel and then mapped to constellations using Gray coding to obtain public information constellation points and private information constellation points for each user. Load the public information constellation points onto the first group of subcarriers; A chaotic key for each user is generated using a chaotic system, and each user's private information constellation points are loaded onto a second set of subcarriers whose order is shuffled by the chaotic key. Perform inverse fast Fourier transform and parallel-to-serial conversion on the public information constellation points on the first group of subcarriers and the private information constellation points on the second group of subcarriers. Assign the first power to the public information constellation points after parallel-to-serial conversion to obtain the public information of all users; By assigning a second power value, which is less than the first power, to the constellation points of the private information after parallel-to-serial conversion, the private information of all users is obtained. By superimposing all users' public information and all users' private information into an RSMA signal, it is transmitted to the optical fiber channel.

2. The signal rate splitting and transmission method suitable for optical fiber communication according to claim 1, characterized in that, After performing inverse fast Fourier transform and parallel-to-serial conversion on the public information constellation points on the first set of subcarriers and the private information constellation points on the second set of subcarriers, the method further includes adding a cyclic prefix / suffix to the public information constellation points and private information constellation points after the parallel-to-serial conversion.

3. The signal rate splitting and transmission method suitable for optical fiber communication according to claim 1, characterized in that, The public information and private information of all users are respectively represented as follows: ； ； In the formula, Indicates the current time Public information of all users Indicates the first Common information constellation points modulated on each subcarrier, Indicates public information. Represents the base of natural numbers. Represents the imaginary unit. Indicates the current time No. The frequency of each subcarrier This represents a sequence of public information mapping indexes for all users. Indicates the current time. All users' private information Indicates private information. Indicates the first The first user's private information constellation point modulated on each subcarrier. Indicates the first The private information constellation points of the second user modulated on each subcarrier, Indicates the first The modulation on the nth subcarrier Each user's private information constellation points This represents the first user's private information mapping index sequence. This represents the private information mapping index sequence of the second user. Indicates the first A sequence of private information mapping indexes for each user.

4. The signal rate splitting and transmission method suitable for optical fiber communication according to claim 3, characterized in that, The RSMA signal is represented as: ； In the formula, Indicates RSMA signal, Indicates the first power. This indicates the second power.

5. The signal rate splitting and transmission method suitable for optical fiber communication according to claim 1, characterized in that, A chaotic key is generated for each user using a chaotic system. Each user's private information constellation points are then loaded onto a second set of subcarriers whose order is shuffled using the chaotic key. This includes: Divide the m subcarriers into m / n groups, where n represents the number of users; The z-th, n+z-th, ..., m-n+z-th subcarriers are combined into the z-th subcarrier group and assigned to the private information constellation points of the z-th user, where 1≤z≤n, and the number of subcarriers assigned to each user is the same as the number of private information constellation points of each user. The Tent / Logistic chaotic system receives the initial value of the z-th user as input and iteratively generates the z-th chaotic sequence. Then, it sorts the sequences by size to generate the mapping index sequence of the z-th user. Based on the mapping index sequence of the z-th user, the order of the subcarriers in the z-th subcarrier group is shuffled, and the private information constellation points of the z-th user are mapped onto the shuffled z-th subcarrier group. The number of iterations is the same as the number of subcarriers in the z-th subcarrier group.

6. The signal rate splitting and transmission method suitable for optical fiber communication according to claim 5, characterized in that, If only information from two users is obtained, a chaotic key is generated for each user using a chaotic system. The constellation points of each user's private information are then loaded onto a second set of subcarriers whose order is shuffled using the chaotic key, including: Odd-numbered subcarriers are assigned to the private information constellation points of user 1, and even-numbered subcarriers are assigned to the private information constellation points of user 2, wherein the number of odd-numbered subcarriers and even-numbered subcarriers is the same as the number of all private information constellation points. The Tent chaotic system receives the initial value of user 1 as input and iterates to generate the first chaotic sequence. Then, it sorts the sequence by size to generate the first mapping index sequence. Based on the first mapping index sequence, the order of odd subcarriers is shuffled, and the constellation points of user 1's private information are mapped onto the shuffled odd subcarriers. The number of iterations is the same as the number of odd subcarriers. A Logistic chaotic system is used as input to generate a second chaotic sequence through iteration. The sequence is then sorted by size to generate a second mapping index sequence. Based on the second mapping index sequence, the order of even subcarriers is shuffled, and the constellation points of user 2's private information are mapped onto the shuffled even subcarriers. The number of iterations is the same as the number of even subcarriers.

7. A signal rate splitting and receiving method suitable for optical fiber communication, characterized in that, Performed by the fiber channel receiver, including: Receive RSMA signals; The first channel information is obtained by channel evaluation based on RSMA signals; Zero-forced equalization of the channel is performed based on the first channel information to obtain the first channel information after channel equalization. Demodulate the first channel information after channel equalization to obtain the common information of all users; Obtain the target user's public information from the public information of all users; The common information of all users is remodulated, and the remodulated common information of all users is subtracted from the RSMA signal. Then, channel evaluation is performed to obtain the second channel information. Zero-forced equalization of the channel is performed based on the second channel information to obtain the equalized second channel information. Demodulation is performed based on the second channel information after channel equalization to obtain the private information of all users; A chaotic key for each user is generated using a chaotic system, and each user's private information is obtained from the private information of all users. By overlaying each user's public and private information, we obtain each user's information; The user’s chaotic key is the same as the chaotic key generated by the user at the fiber optic channel transmitter. The RSMA signal is the RSMA signal transmitted by the signal rate splitting transmission method for optical fiber communication as described in any one of claims 1-6.

8. The signal rate splitting and receiving method for optical fiber communication according to claim 7, characterized in that, Demodulation is performed based on the first channel information after channel equalization to obtain the common information of all users, including: The received RSMA signal is converted from serial to parallel to obtain the RSMA time-domain signal matrix; If the fiber optic signal transmitter adds a cyclic prefix / suffix to the public information constellation points and private information constellation points after parallel-to-serial conversion, then the RSMA time-domain signal matrix is ​​de-cyclically prefixed / suffixed and then subjected to a fast Fourier transform to obtain an RSMA frequency-domain signal containing public and private information. Otherwise, perform a fast Fourier transform directly to obtain an RSMA frequency domain signal containing both public and private information; Based on the public information mapping index sequence of all users at the optical fiber signal transmitter, the superimposed information of the public information and the private information of all users is extracted from the RSMA frequency domain signal containing public and private information. By dividing the superimposed information of all users' public information and all users' private information by the first channel information, the equalized superimposed information of all users' public information and all users' private information is obtained. Disrupt all users' private information by dividing the sum of the balanced public and private information of all users by [the factor]. It obtains the public constellation points of all users; Demap the constellation points of the public information of all users to obtain the public information of all users; in, This represents the first power allocated by the fiber optic channel transmitter to the public information constellation points after parallel-to-serial conversion.

9. The signal rate splitting and receiving method for optical fiber communication according to claim 8, characterized in that, Demodulation is performed based on the second channel information after channel equalization to obtain the private information of all users, including: The public information of all users is remodulated to obtain the remodulated public information of all users; Based on the private information mapping index sequence of all users at the optical fiber signal transmitter, the superimposed information of the public information and the private information of all users is extracted from the RSMA frequency domain signal containing public information and private information. By subtracting the remodulated public information of all users from the superimposed information of all users' public information and private information, we can obtain the private information of all unbalanced users. Divide the private information of all users by the channel information to obtain the equalized private information of all users; Divide the balanced private information of all users by It obtains the private constellation points of all users; Demapping the constellation points of all users' private information yields the private information of all users. in, This represents the second power allocated by the fiber optic channel transmitter to the private information constellation points after parallel-to-serial conversion.

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