Signal transmission method, signal receiving method, channel sending end and channel receiving end

Abstract

The invention discloses a signal transmission method, a signal receiving method, a channel sending end and a channel receiving end, and belongs to the technical field of communication, and the signal transmission method comprises the steps: obtaining to-be-sent original data, and generating a bit encryption factor, a constellation encryption factor, a bit disturbance factor and a constellation disturbance factor; the method comprises the following steps: dividing original data to be sent into even number of data blocks according to a preset rule to construct a complete binary tree, and carrying out first traversal encryption and primary disturbance on the data blocks by utilizing a bit encryption factor; converting the data block subjected to primary perturbation into a parallel bit stream through serial-parallel conversion, performing QAM mapping on the parallel bit stream, and performing second traversal encryption and second perturbation according to a constellation perturbation factor; the parallel bit streams after secondary disturbance are converted into serial signals through a discrete Fresnel inverse transformation matrix and parallel-serial conversion; and performing up-conversion processing on the serial signal and transmitting the serial signal to a transmission channel. According to the invention, the problem of insufficient safety protection in practical application in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to a signal transmission method, a signal receiving method, a channel transmitting end and a channel receiving end, and belongs to the technical field of communications. Background Art

[0002] With the continued development of emerging technologies such as big data, the Internet of Things, and cloud computing, the demand for information transmission is exploding. Optical internetworks are facing pressure to expand capacity, while security risks in the communication data exchange process are becoming increasingly prominent. Orthogonal Chirp Division Multiplexing (OCDM) technology has gradually attracted attention due to its high anti-interference capabilities, high spectral efficiency, and high compatibility with OFDM (Orthogonal Frequency Division Multiplexing) systems. OCDM's chirped waveform has strong pulse compression and spectrum spreading capabilities, and can effectively utilize multipath diversity, outperforming OFDM in performance. To address security challenges, existing technologies based on digital domain chaotic encryption leverage the extreme sensitivity, dynamic nonlinear behavior, and high entropy of chaotic systems to provide complexity and unpredictability for communication encryption. Its chaotic sequences demonstrate excellent security in data scrambling, key generation, and mapping control, while minimally impacting system throughput. In addition, as a classic data structure, the binary tree structure provides flexible path control capabilities for the layered encryption mechanism through various traversal methods such as pre-order traversal, in-order traversal, post-order traversal and hierarchical traversal, which can enhance the randomness and complexity of the encryption algorithm.

[0003] Despite the advantages of OCDM technology, its widespread deployment in high-throughput scenarios also presents complex security challenges: the risk of malicious eavesdropping and information tampering has increased significantly, necessitating enhanced system protection capabilities. Furthermore, the point-to-multipoint downlink broadcast transmission mechanism in passive optical networks (PONs) allows any user to receive downlink signals from other users, further threatening data security. Existing technologies still face inadequate security protection in practical applications. Developing efficient physical layer security mechanisms to build a robust information protection barrier has become a key direction for the evolution of optical communication systems. Summary of the Invention

[0004] The purpose of the present invention is to provide a signal transmission method, a signal receiving method, a channel transmitting end and a channel receiving end, which solve the problem of insufficient security protection faced by the existing technology in practical applications by performing full binary tree hierarchical joint encryption on bit information and constellation mapping.

[0005] In order to solve the above technical problems, the present invention is implemented by adopting the following technical solutions.

[0006] In a first aspect, the present invention provides a signal transmission method, performed by a channel transmitting end, comprising:

[0007] Get the original data and initial key value to be sent;

[0008] Based on the initial value of the key, four groups of chaotic sequences are synchronously generated using a hyperchaotic system;

[0009] Two sets of chaotic sequences are used to generate bit encryption factors and constellation encryption factors;

[0010] Using another two groups of chaotic sequences to generate bit perturbation factors and constellation perturbation factors;

[0011] Divide the original data to be sent into an even number of data blocks according to a preset rule to construct a complete binary tree, where leaf nodes store data blocks and non-leaf nodes store hierarchically encoded routing information;

[0012] Based on the bit encryption factor and the bit perturbation factor, performing first-pass encryption and primary perturbation on the data block using the bit encryption factor;

[0013] Converting the primary perturbed data block into a parallel bit stream through serial-to-parallel conversion;

[0014] Based on the constellation encryption factor and the constellation perturbation factor, QAM mapping is performed on the parallel bit streams and second-pass encryption and secondary perturbation are performed according to the constellation perturbation factor;

[0015] Converting the parallel bit stream after the secondary disturbance into a serial signal through the discrete Fresnel inverse transform matrix and parallel-to-serial conversion;

[0016] The serial signal is up-converted and transmitted to the transmission channel.

[0017] Furthermore, the hyperchaotic system includes a Zhan-4D hyperchaotic system, and the Zhan-4D hyperchaotic system is expressed as:

[0018] ;

[0019] Where, Represents the state variables of the Zhan-4D hyperchaotic system on the horizontal axis The first derivative of Represents the state variables of the Zhan-4D hyperchaotic system on the vertical axis The first derivative of Represents the state variables of the vertical axis of the Zhan-4D hyperchaotic system The first derivative of represents the state feedback control parameters of the Zhan-4D hyperchaotic system The first derivative of represents the first system parameter of the Zhan-4D hyperchaotic model, represents the second system parameter of the Zhan-4D hyperchaotic model, represents the third system parameter of the Zhan-4D hyperchaotic model, represents the fourth system parameter of the Zhan-4D hyperchaotic model, represents the fifth system parameter of the Zhan-4D hyperchaotic model, represents the sixth system parameter of the Zhan-4D hyperchaotic model, represents the seventh system parameter of the Zhan-4D hyperchaotic model, represents the eighth system parameter of the Zhan-4D hyperchaotic model, where 、 、 、 、 、 、 and Jointly control the chaotic behavior of the Zhan-4D hyperchaotic system.

[0020] Furthermore, the bit encryption factor, bit perturbation factor, constellation encryption factor and constellation perturbation factor are respectively expressed as:

[0021] ;

[0022] Where, represents the bit encryption factor, represents the bit perturbation factor, represents the constellation encryption factor, represents the constellation perturbation factor, Remaining operation, represents an arithmetic function that rounds toward negative infinity, represents the first chaotic sequence among the four chaotic sequences, represents the second chaotic sequence among the four chaotic sequences, represents the third chaotic sequence among the four chaotic sequences, Represents the fourth chaotic sequence among the four groups of chaotic sequences.

[0023] Furthermore, it also includes:

[0024] Perform the following recursive operations on the data block stored in each leaf node of the complete binary tree:

[0025] Divide the current data block into an even number of sub-data blocks according to the same preset rule;

[0026] Construct a corresponding complete binary tree for each sub-data block as a sub-complete binary tree;

[0027] The recursion stops until the data block reaches a minimum granularity, wherein the minimum granularity is a bit data stream.

[0028] Further, the primary perturbation or the secondary perturbation comprises:

[0029] At each recursive level of the complete binary tree, a preset perturbation algorithm is performed on the current sub-complete binary tree to independently perform perturbation processing.

[0030] Further, the method for traversing the data block comprises: pre-order traversal, in-order traversal, post-order traversal, and level-order traversal.

[0031] In a second aspect, the present application provides a signal receiving method, executed by a channel receiving end, comprising:

[0032] Receiving the up-converted serial signal in the transmission channel and generating four groups of chaotic sequences identical to those of the channel transmitting end by using the hyper-chaotic system synchronization based on the same key initial value as the channel transmitting end;

[0033] Generating a bit encryption factor and a constellation encryption factor by using two groups of chaotic sequences;

[0034] Generating a bit perturbation factor and a constellation perturbation factor by using the other two groups of chaotic sequences;

[0035] Down-converting the up-converted serial signal to recover the serial signal;

[0036] Recovering the parallel bit stream after the secondary perturbation by serial-parallel conversion and discrete Fresnel transform matrix from the serial signal;

[0037] Based on the constellation encryption factor and the constellation perturbation factor, performing QAM inverse mapping on the parallel bit stream and performing second traversal decryption and secondary perturbation according to the constellation perturbation factor;

[0038] Recovering the data block after the primary perturbation by parallel-serial conversion from the parallel bit stream;

[0039] Based on the bit encryption factor and the bit perturbation factor, removing the primary perturbation and performing traversal decryption to recover the data block stored in the leaf node from the data block after the primary perturbation according to the bit encryption factor;

[0040] According to the complete binary tree block structure, based on the hierarchical encoding routing information stored in the non-leaf node, the data block stored in the leaf node is combined and recovered into the original data according to the same preset rule as the channel transmitting end.

[0041] Further, the discrete Fresnel transform matrix is represented as:

[0042] ;

[0043] Where, represents the Fresnel transform The first Rank The modulation signal of represents the number of chirp subcarriers, represents a vector, Represents the remainder operation.

[0044] In a third aspect, the present invention provides a channel transmitting end, comprising the following modules:

[0045] The data acquisition module is used to obtain the original data to be sent and the initial value of the key;

[0046] A factor generation module is used to synchronously generate four sets of chaotic sequences using a hyperchaotic system based on the initial value of the key; two sets of chaotic sequences are used to generate bit encryption factors and constellation encryption factors, and the other two sets of chaotic sequences are used to generate bit perturbation factors and constellation perturbation factors;

[0047] A data construction module is used to divide the original data to be sent into an even number of data blocks according to a preset rule to construct a complete binary tree, wherein the leaf nodes store the data blocks and the non-leaf nodes store the hierarchically encoded routing information;

[0048] A primary encryption module, configured to perform first-pass encryption and primary perturbation on a data block using the bit encryption factor based on the bit encryption factor and the bit perturbation factor;

[0049] A time-frequency conversion module is used to convert the primary perturbed data block into a parallel bit stream through serial-to-parallel conversion;

[0050] A secondary encryption module, configured to perform QAM mapping on the parallel bit streams based on the constellation encryption factor and the constellation perturbation factor, and perform a second traversal encryption and secondary perturbation according to the constellation perturbation factor;

[0051] A signal conversion module, used for converting the parallel bit stream after the secondary disturbance into a serial signal through a discrete Fresnel inverse transform matrix and parallel-to-serial conversion;

[0052] The frequency conversion processing module is used to perform up-conversion processing on the serial signal and transmit it to the transmission channel.

[0053] In a fourth aspect, the present invention provides a channel receiving end, comprising the following modules:

[0054] The data acquisition module is used to receive the serial signal after up-conversion processing in the transmission channel and synchronously generate four groups of chaotic sequences identical to those at the channel transmitting end using a hyperchaotic system based on the same initial key value as that at the channel transmitting end;

[0055] A factor generation module, configured to generate a bit encryption factor and a constellation encryption factor using two sets of chaotic sequences, and to generate a bit perturbation factor and a constellation perturbation factor using another two sets of chaotic sequences;

[0056] The frequency conversion inverse processing module is used to perform down-conversion processing on the serial signal after up-conversion processing and restore it to a serial signal;

[0057] A signal inverse conversion module is used to restore the serial signal to a parallel bit stream after quadratic perturbation through serial-to-parallel conversion and discrete Fresnel transformation matrix;

[0058] A secondary decryption module is used to remove the initial disturbance from the data block after the initial disturbance based on the bit encryption factor and perform traversal decryption to restore the data block stored in the leaf node;

[0059] A time-frequency inverse conversion module is used to restore the parallel bit stream to the data block after the initial disturbance through parallel-to-serial conversion;

[0060] A primary decryption module is used to remove the initial disturbance from the data block after the initial disturbance based on the bit encryption factor and perform traversal decryption to restore the data block stored in the leaf node;

[0061] A data reconstruction module is used to restore the data blocks stored in the leaf nodes to the original data according to the same preset rules as the channel sending end based on the hierarchical coding routing information stored in the non-leaf nodes according to the complete binary tree block structure;

[0062] The serial signal after up-conversion processing is obtained through the signal transmission method described in the first aspect.

[0063] Compared with the prior art, the present invention has the following beneficial effects:

[0064] 1. At the channel transmitter, this invention uses a hierarchical architecture based on a complete binary tree to store hierarchically encoded routing information in non-leaf nodes, effectively reducing the path complexity of data block traversal encryption. It also generates bit encryption factors, bit perturbation factors, constellation encryption factors, and constellation perturbation factors through a hyperchaotic sequence. By utilizing two independent traversal encryptions, it significantly improves resistance to malicious eavesdropping and information tampering. The introduction of a discrete inverse Fresnel transform matrix further optimizes the signal spectrum characteristics, enhancing the system's security level while maintaining high anti-interference performance. This makes it suitable for the high confidentiality requirements of broadcast transmission scenarios such as passive optical networks, addressing the inadequate security protection issues faced by existing technologies in practical applications.

[0065] 2. The present invention uses a hierarchical architecture based on a complete binary tree at the receiving end of the channel to store hierarchical coding routing information through non-leaf nodes, ensuring that leaf node data blocks are accurately merged at the receiving end of the channel according to preset rules consistent with the channel transmitting end, thereby reducing the complexity and bit error rate of data reorganization. It also generates bit encryption factors and constellation perturbation factors through a hyperchaotic sequence, and uses two independent traversal decryptions, which are completely reverse-aligned with the encryption process at the channel transmitting end, significantly improving the robustness against noise interference and malicious attacks. At the same time, the introduction of the discrete Fresnel transform matrix further optimizes the signal spectrum recovery accuracy through a strict correspondence with the inverse transform. While maintaining high demodulation efficiency, it reduces the system security synchronization error rate, making it suitable for high-reliability reception requirements in broadcast transmission scenarios such as passive optical networks. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Figure 1 This is an overall schematic diagram of a signal transmission method and a signal receiving method provided by an embodiment of the present invention;

[0067] Figure 2 Schematic diagram of the principles of OCDM modulation and demodulation provided by an embodiment of the present invention;

[0068] Figure 3 Schematic diagram of the structure of a complete binary tree provided by an embodiment of the present invention;

[0069] Figure 4 Schematic diagram of data blocks in different traversal modes provided by an embodiment of the present invention;

[0070] Figure 5 This is a schematic diagram of a process for constructing a complete binary tree according to an embodiment of the present invention;

[0071] Figure 6 is a schematic diagram of a secondary disturbance provided by an embodiment of the present invention;

[0072] Figure 7 Schematic diagram of the attractor phase diagram of the Zhan-4D hyperchaotic system provided by an embodiment of the present invention;

[0073] Figure 8 This is a schematic diagram of the key sensitivity of the Zhan-4D hyperchaotic model provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0074] The technical solution of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations on the technical solution of the present invention. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0075] The term "and / or" simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. Additionally, the character " / " generally indicates an "or" relationship between the related objects.

[0076] Example 1

[0077] This embodiment introduces a signal transmission method, which is performed by a channel transmitting end and includes:

[0078] Step 1: Get the original data to be sent and the initial key value;

[0079] This embodiment obtains the original data to be transmitted and the initial key value, and leverages the extreme sensitivity and high entropy of its initial conditions and control parameters to provide a highly complex and unpredictable random sequence source for subsequent encryption and perturbation processes. Compared to traditional pseudo-random sequences, the dynamic nonlinear behavior of hyperchaotic sequences significantly enhances the key space's resistance to cracking, establishing a reliable random foundation for physical layer security mechanisms.

[0080] Step 2: Based on the initial value of the key, four groups of chaotic sequences are synchronously generated using the hyperchaotic system. Two groups of chaotic sequences are used to generate bit encryption factors and constellation encryption factors. The other two groups of chaotic sequences are used to generate bit perturbation factors and constellation perturbation factors.

[0081] This embodiment achieves decoupled control of the encryption and perturbation processes by independently generating bit encryption factors, constellation encryption factors, and bit perturbation factors in groups. The bit encryption factor and bit perturbation factor focus on basic security protection at the data block level, while the constellation encryption factor and constellation perturbation factor provide deep interference at the modulation symbol layer. The synergistic effect of these two factors effectively defends against chosen-plaintext attacks and statistical analysis attacks, improving the system's anti-eavesdropping capabilities compared to traditional single-factor encryption schemes.

[0082] Step 3: Divide the original data to be sent into an even number of data blocks according to a preset rule to construct a complete binary tree, wherein the leaf nodes store the data blocks and the non-leaf nodes store the hierarchically encoded routing information.

[0083] This embodiment, based on a hierarchical architecture based on a complete binary tree, stores hierarchically encoded routing information in non-leaf nodes, enabling explicit control of data block processing paths. Compared to a linear structure, the binary tree structure reduces the complexity of data block traversal. Furthermore, the hierarchical storage of routing information provides precise path guidance for subsequent data reassembly at the decryption end, significantly reducing the bit error rate at the receiving end of the channel.

[0084] Step 4: Based on the bit encryption factor and the bit perturbation factor, the data block is encrypted and perturbed for the first time using the bit encryption factor.

[0085] The first traversal encryption is performed on the data block by a bit encryption factor, and a primary disturbance mechanism is combined to establish a basic security barrier at the data block level. The traversal encryption ensures that each data bit is independently encrypted, and the primary disturbance destroys the statistical characteristics of the data by bit flipping or permutation driven by a chaotic sequence, thereby improving the threshold for malicious eavesdroppers to obtain effective information.

[0086] Step five: The data block after the primary disturbance is converted into a parallel bit stream through serial-parallel conversion.

[0087] The serial data stream is reconstructed into a parallel bit stream through serial-parallel conversion, which provides parallel processing capability for QAM mapping and secondary disturbance. Compared with serial processing, the parallel architecture improves the system throughput, and the independent channel characteristics of the parallel bit stream provide physical layer support for the implementation of the layered encryption mechanism.

[0088] Step six: Based on the constellation encryption factor and the constellation disturbance factor, the parallel bit stream is QAM mapped, and the second traversal encryption and secondary disturbance are performed according to the constellation disturbance factor.

[0089] The parallel bit stream is converted into modulation symbols through QAM mapping, and the second traversal encryption and secondary disturbance are performed in combination with the constellation disturbance factor to establish a deep security protection at the symbol level. The secondary disturbance destroys the correlation between symbols through constellation point offset or phase rotation driven by a chaotic sequence, thereby improving the noise immunity of traditional QAM mapping.

[0090] Step seven: The parallel bit stream after secondary disturbance is converted into a serial signal through a discrete Fresnel inverse transform matrix and serial-parallel conversion.

[0091] The signal spectrum characteristics are optimized through frequency-time domain conversion by the discrete Fresnel inverse transform matrix, which reduces the peak-to-average power ratio and effectively suppresses nonlinear distortion. In addition, the serial signal is reconstructed through serial-parallel conversion, which maintains high anti-interference performance while improving system spectral efficiency.

[0092] Step eight: The serial signal is up-converted and transmitted to the transmission channel.

[0093] The baseband signal is shifted to a high frequency band through up-conversion, which expands the spectral coverage of signal transmission and adapts to the characteristics of multipath fading channels. Compared with direct transmission, the up-conversion mechanism reduces signal penetration loss, and high-frequency deployment effectively avoids low-frequency congestion, thereby improving the capacity expansion capability of optical interconnection networks in high-concurrency scenarios.

[0094] Embodiment 2

[0095] Based on the same inventive concept as example 1, this embodiment introduces a signal receiving method, executed by a channel receiving end, comprising:

[0096] Step one: receive the up-converted serial signal in the transmission channel and generate four groups of chaotic sequences identical to the channel sending end based on the same key initial value and the super chaotic system synchronization.

[0097] This embodiment uses the channel receiving end to generate four groups of chaotic sequences identical to the channel sending end through super chaotic system synchronization, and uses the initial condition sensitivity and dynamic evolution consistency of the super chaotic system to ensure the high matching of the key space of the encryption and decryption ends. Compared with the non-synchronous chaotic system, the key mismatch rate is reduced, and a reliable randomness basis is provided, which fundamentally guarantees the reversibility of the physical layer security mechanism.

[0098] Step two: generate bit encryption factors and constellation encryption factors using two groups of chaotic sequences, and generate bit disturbance factors and constellation disturbance factors using the other two groups of chaotic sequences.

[0099] This embodiment independently generates bit encryption factors and constellation disturbance factors by grouping, realizing decoupling control of the decryption process of the channel receiving end. The bit encryption factor focuses on basic security removal at the data block level, and the constellation disturbance factor performs deep descrambling at the modulation symbol layer, and the two work together to effectively resist chosen ciphertext attacks and differential attacks, improving the system cracking resistance.

[0100] Step three: down-convert the up-converted serial signal to restore it to a serial signal.

[0101] This embodiment migrates the high-frequency serial signal to the baseband frequency band through down-conversion, significantly reducing signal penetration loss and multipath fading effects. Compared with directly processing high-frequency signals, the down-conversion mechanism improves the receiving sensitivity, and the low-frequency characteristics of the baseband signal provide more stable physical layer support for subsequent serial-parallel conversion and digital signal processing.

[0102] Step four: restore the serial signal to a parallel bit stream after secondary disturbance through serial-parallel conversion and discrete Fresnel transform matrix.

[0103] This embodiment reconstructs the serial signal into a parallel bit stream through serial-parallel conversion, and recovers the frequency spectrum characteristics of the inverse discrete Fresnel transform of the channel sending end by combining the frequency domain and time domain conversion characteristics of the discrete Fresnel transform matrix. Compared with traditional FFT transform, the DFrT matrix reduces the signal spectrum distortion rate, providing a high-fidelity parallel data source for subsequent constellation descrambling and QAM demapping.

[0104] Step 5: Based on the constellation encryption factor and the constellation perturbation factor, perform QAM inverse mapping on the parallel bit streams and perform a second traversal decryption and secondary perturbation according to the constellation perturbation factor.

[0105] This embodiment implements secondary perturbation removal and ergodic decryption using constellation perturbation factors, combined with QAM demapping to establish a deeply secure demodulation mechanism at the symbol level. Secondary perturbation removal accurately restores the effects of constellation perturbations on the transmitting end of the channel by reversely shifting or rotating the constellation points driven by a chaotic sequence, reducing the demodulation symbol error rate of traditional QAM systems. Meanwhile, ergodic decryption ensures that each symbol is independently verified, significantly improving noise immunity.

[0106] Step 6: Restore the parallel bit stream to the data block after the initial disturbance through parallel-to-serial conversion.

[0107] This embodiment reconstructs parallel bit streams into serial data blocks through parallel-to-serial conversion, providing an efficient processing architecture for initial perturbation removal at the data block level. Compared to parallel processing, the serial architecture reduces processing latency at the receiving end of the channel. Furthermore, the continuity of serial data blocks provides a precise timing alignment foundation for data reassembly within a complete binary tree structure.

[0108] Step 7: Based on the bit encryption factor and the bit perturbation factor, remove the initial perturbation from the data block after the initial perturbation according to the bit encryption factor and perform traversal decryption to restore the data block stored in the leaf node.

[0109] This embodiment implements initial disturbance removal and traversal decryption through bit encryption factors, and establishes a reverse mechanism for basic security protection at the data block level. Traversal decryption ensures that each data bit is independently verified. Combined with bit flipping or permutation recovery driven by chaotic sequences, it improves the detection rate of maliciously tampered data. At the same time, it cooperates with the routing information stored in non-leaf nodes to provide a path basis for the precise positioning of data blocks.

[0110] Step 8: Based on the complete binary tree block structure and the hierarchical coding routing information stored in the non-leaf nodes, the data blocks stored in the leaf nodes are merged and restored to the original data according to the same preset rules as the channel sending end.

[0111] This embodiment, based on a hierarchical architecture based on a complete binary tree, uses hierarchically encoded routing information stored in non-leaf nodes to achieve explicit reverse tracing of data block processing paths. Compared to a linear structure, the binary tree structure reduces the complexity of data block reassembly. Furthermore, the hierarchical storage of routing information ensures that leaf node data blocks are accurately merged according to pre-set rules at the channel transmitter, reducing the bit error rate at the channel receiver.

[0112] Example 3

[0113] like Figure 1As shown, based on the same inventive concept as other embodiments, this embodiment introduces the implementation steps of a signal transmission method and a corresponding signal receiving method. This embodiment first uses the Zhan-4D hyperchaotic system to generate four groups of chaotic sequences, then uses two of the chaotic sequences to respectively determine the traversal methods of data bits and constellation mapping rules, and finally uses the other two groups of chaotic sequences to specify the traversal rules of the complete binary tree to implement binary tree hierarchical encryption, while reducing the complexity of the algorithm, achieving high-security transmission of large amounts of data. This embodiment enhances the randomness and unpredictability of the encryption system by integrating chaotic dynamics with the complexity of the tree structure, ensuring the security of information transmission. The solution provided by this embodiment has a key space of up to 10191, which significantly improves the anti-attack capability of the encryption system and is suitable for building a future-oriented high-security optical communication network architecture.

[0114] On the sending side of the channel, perform the following steps:

[0115] Step 1: Get the original data to be sent and the initial key value.

[0116] Step 2: Based on the initial value of the key, four groups of chaotic sequences are synchronously generated using the hyperchaotic system. Two groups of chaotic sequences are used to generate bit encryption factors and constellation encryption factors. The other two groups of chaotic sequences are used to generate bit perturbation factors and constellation perturbation factors.

[0117] In this embodiment, the hyperchaotic system includes a Zhan-4D hyperchaotic system, and the Zhan-4D hyperchaotic system is expressed as:

[0118] ;

[0119] Where, Represents the state variables of the Zhan-4D hyperchaotic system on the horizontal axis The first derivative of Represents the state variables of the Zhan-4D hyperchaotic system on the vertical axis The first derivative of Represents the state variables of the vertical axis of the Zhan-4D hyperchaotic system The first derivative of represents the state feedback control parameters of the Zhan-4D hyperchaotic system The first derivative of represents the first system parameter of the Zhan-4D hyperchaotic model, represents the second system parameter of the Zhan-4D hyperchaotic model, represents the third system parameter of the Zhan-4D hyperchaotic model, represents the fourth system parameter of the Zhan-4D hyperchaotic model, a fifth system parameter of a Zhan-4D hyperchaotic model, a sixth system parameter of the Zhan-4D hyperchaotic model, a seventh system parameter of the Zhan-4D hyperchaotic model, an eighth system parameter of the Zhan-4D hyperchaotic model, , , , , , , and jointly control the chaotic behavior of the Zhan-4D hyperchaotic system.

[0120] When = 8, =-1, =-40, =1, =2, =-14, =1, =-2, the Zhan-4D hyperchaotic system is in a hyperchaotic state and has a four-wing property. The dynamic behavior of the four-wing hyperchaotic system is more complex and is suitable for data encryption processing. Figure 7 is a schematic diagram of an attractor phase portrait of a Zhan-4D hyperchaotic system provided by an embodiment of the present application, wherein Figure 7 (a) in (a) represents a projection of the attractor phase portrait in x-y-z, Figure 7 (b) in (b) represents a projection of the attractor phase portrait in x-y, Figure 7 (c) in (c) represents a projection of the attractor phase portrait in x-z, Figure 7 (d) in (d) represents a projection of the attractor phase portrait in y-z; in Figure 7 , the initial condition ( , , , )=(0.1, 0.1, 0.1, 0.1), it can be seen that the phase portrait of the Zhan-4D hyperchaotic model shows complex chaotic trajectories and bifurcation dynamics. Due to the sensitivity of the hyperchaotic model to initial values, when the chaotic initial value changes slightly, almost completely different complex chaotic trajectories are generated.

[0121] When , , , After the chaotic sequence is generated, it cannot be directly used for encryption of the bit stream and the 16QAM constellation diagram. Data preprocessing of the chaotic sequence is required to match the signal format. In this embodiment, the bit encryption factor, bit perturbation factor, constellation encryption factor, and constellation perturbation factor are respectively expressed as:

[0122] ;

[0123] Where, represents the bit encryption factor, represents the bit perturbation factor, represents the constellation encryption factor, represents the constellation perturbation factor, Remaining operation, represents an arithmetic function that rounds toward negative infinity, represents the first chaotic sequence among the four chaotic sequences, represents the second chaotic sequence among the four chaotic sequences, represents the third chaotic sequence among the four chaotic sequences, Represents the fourth chaotic sequence among the four groups of chaotic sequences.

[0124] Step 3: Divide the original data to be sent into an even number of data blocks according to a preset rule to construct a complete binary tree.

[0125] A complete binary tree is a typical tree data structure, in which each node has at most two child nodes, called the left child node and the right child node, such as Figure 3 As shown in Figure 2. Complete binary tree structures offer excellent hierarchical organization and controllable traversal in computer algorithms. Common traversal methods include pre-order traversal, in-order traversal, post-order traversal, and level traversal. Due to the fundamental differences in the order in which these traversal methods access nodes, the same complete binary tree can generate completely different node sequences under different traversal methods, providing a natural perturbation space for data encryption.

[0126] This embodiment selects a specific traversal method to access the nodes of the complete binary tree, and thus obtains a set of encrypted bit streams with a specific arrangement order. Figure 4 As shown, the bit sequence [101110011011101] will produce completely different encoding results under different traversal methods. Because the node access order corresponding to each traversal method varies significantly, it is difficult for an external attacker to recover the original data without valid information about the traversal method and the tree-shaped tree rules. This embodiment significantly improves system security through the diversity of traversal methods and also lays a structural foundation for deep encryption operations based on hierarchical structures. The channel receiving end only needs to synchronize the relevant traversal information to reversely restore the original bit stream according to the rules, realizing a reversible encryption process based on key control.

[0127] However, in the actual data transmission process, the bit stream is relatively long. In order to cope with the computational overhead caused by large-scale data streams, this embodiment stipulates the traversal rules of the complete binary tree, such as Figure 5 Shown, including:

[0128] Perform the following recursive operations on the data block stored in each leaf node of the complete binary tree:

[0129] Divide the current data block into an even number of sub-data blocks according to the same preset rule;

[0130] Construct a corresponding complete binary tree for each sub-data block as a sub-complete binary tree;

[0131] The recursion stops until the data block reaches a minimum granularity, where the minimum granularity is a bit data stream.

[0132] In this embodiment, the traversal rules of the complete binary tree significantly reduce the scale of the traversal tree, thereby effectively controlling the time complexity and resource consumption of the encryption algorithm.

[0133] Step 4: Based on the bit encryption factor and the bit perturbation factor, the data block is encrypted and perturbed for the first time using the bit encryption factor.

[0134] The method for traversing the data block in this embodiment includes: pre-order traversal, in-order traversal, post-order traversal and level traversal. In this embodiment, at each recursive level of the complete binary tree, a preset perturbation algorithm is executed on the current sub-complete binary tree to perform independent perturbation processing to complete primary perturbation.

[0135] Step 5: Convert the primary perturbed data block into a parallel bit stream through serial-to-parallel conversion.

[0136] Step 6: Based on the constellation encryption factor and the constellation perturbation factor, perform 16QAM mapping on the parallel bit streams and perform a second traversal encryption and secondary perturbation according to the constellation perturbation factor.

[0137] In this embodiment, based on the traversal rule of the complete binary tree, when performing 16QAM mapping on the parallel bit streams and performing a second traversal encryption according to the constellation perturbation factor, the 16 constellation points are first numbered and a complete binary tree of 16 nodes is constructed. Then, the nodes are reordered according to the selected traversal method to form a new mapping order, such as Figure 6 As shown, this embodiment replaces the original number with the perturbed number to achieve perturbation encryption of the constellation diagram, so that the modulated signal has additional confidentiality. The channel receiving end performs reverse mapping based on the shared traversal method information to restore the original constellation arrangement and ensure the accuracy of demodulation.

[0138] Step 7: Convert the quadratically perturbed parallel bit stream into a serial signal through the inverse discrete Fresnel transform matrix, prefix addition, and parallel-to-serial conversion.

[0139] Orthogonal Chirp Division Multiplexing (OCDM) is an advanced modulation scheme developed by combining the improved traditional Chirp Spread Spectrum (CSS) technology with Orthogonal Frequency Division Multiplexing (OFDM). Unlike traditional OFDM, OCFDM loads data symbols onto a set of It is modulated on orthogonal chirped subcarriers. The orthogonal chirped subcarriers have good orthogonality with each other, thereby enabling efficient transmission and demodulation of signals.

[0140] In OCDM, The data symbol passes through the Orthogonal chirped subcarriers are modulated, which is similar to the OFDM technology. The symbol passes The modulation method of the orthogonal frequency subcarrier is similar to that of the orthogonal chirp division multiplexing technology. The modulation and demodulation principle of the orthogonal chirp division multiplexing technology is as follows: Figure 2 As shown, Indicates the 0th symbol, Indicates the first symbol, represents the (N-1)th symbol, represents the 0th chirp subcarrier, Indicates the first chirp subcarrier, represents the (N-1)th chirp subcarrier, Indicates the current moment, represents the integral of the transposed 0th chirp subcarrier, represents the integral of the transposed first chirp subcarrier, represents the integral of the transposed (N-1)th chirp subcarrier, represents the 0th demodulated signal, Represents the first demodulated signal, Represents the (N-1)th demodulated signal.

[0141] In this embodiment, OCDM modulation and demodulation are respectively expressed as:

[0142] ;

[0143] Where, Indicates the current time The modulation signal, represents the total number of orthogonal chirp subcarriers, Indicates the modulation signal symbols, Indicates the chirp subcarriers, Represents the entire OCDM symbol period, Indicates the A demodulated signal, Indicates the The transpose of the chirp subcarriers, express The differential of .

[0144] In digital domain communications, discrete Fresnel transform (DFnT) is often used to implement OCDM modulation. DFnT is an integral transform derived from classical optics and is a mathematical formula for describing near-field optical diffraction. Its core expression is:

[0145] ;

[0146] Where, Indicates the current time The chirp parameter is The Fresnel transform of represents a vector, represents a natural constant, Used to control the speed of Fresnel transform frequency change.

[0147] In this embodiment, the discrete Fresnel transform matrix is ​​expressed as:

[0148] ;

[0149] Where, represents the Fresnel transform The first Rank The modulation signal of represents the number of chirp subcarriers, represents a vector, Represents the remainder operation.

[0150] The discrete Fresnel transform matrix can be decomposed into ,in Represents the discrete Fresnel transform matrix, which is used to transform the time domain signal into the frequency domain. and They represent the first chirp matrix and the second chirp matrix, which are responsible for modulation in the time domain and frequency domain respectively. Each chirp signal has good orthogonality in the time-frequency domain. This orthogonality can effectively combat multipath effects and frequency selective fading in complex wireless communication environments.

[0151] In this embodiment, the first chirp matrix and the second chirp matrix are respectively expressed as:

[0152] ;

[0153] ;

[0154] Where, Indicates the The first chirp matrix, Indicates the A second chirp matrix.

[0155] In this embodiment, the digital modulation of OCDM is expressed in matrix form as follows:

[0156] ;

[0157] Where, The digital modulation matrix representing OCDM is: Represents the inverse discrete Fresnel transform matrix, which is the discrete Fresnel transform matrix The complex conjugate transposed matrix of represents transpose, represents the modulation matrix.

[0158] In this embodiment, the digital demodulation process using the digital modulation matrix is ​​expressed as:

[0159] ;

[0160] Where, Represents the matrix after digital demodulation.

[0161] In summary, the additional complexity of the digital demodulation process using digital modulation matrix compared to OFDM mainly comes from the first chirp matrix and the second chirp matrix. and From the matrix perspective, the first chirp matrix and the second chirp matrix and is a sparse diagonal matrix where only the main diagonal elements are non-zero and the remaining elements are zero. After introducing the first chirp matrix and the second chirp matrix, the additional computational complexity of each chirp carrier is O(2), so the total additional complexity is O(2N), and the increase in overall complexity is relatively small.

[0162] Step 8: Up-convert the serial signal and transmit it to the transmission channel.

[0163] On the receiving end of the channel, perform the following steps:

[0164] Step 1: Receive the up-converted serial signal in the transmission channel and use the hyperchaotic system to synchronously generate four sets of chaotic sequences that are the same as those at the channel transmitting end based on the same initial key value as that at the channel transmitting end.

[0165] Step 2: Use two sets of chaotic sequences to generate bit encryption factors and constellation encryption factors, and use another two sets of chaotic sequences to generate bit perturbation factors and constellation perturbation factors.

[0166] Step 3: Down-convert the up-converted serial signal to restore it to a serial signal.

[0167] Step 4: The serial signal is restored to a parallel bit stream after quadratic perturbation through serial-to-parallel conversion, prefix removal operation and discrete Fresnel transform matrix.

[0168] Step 5: Based on the constellation encryption factor and the constellation perturbation factor, perform 16QAM inverse mapping on the parallel bit streams and perform a second traversal decryption and secondary perturbation according to the constellation perturbation factor.

[0169] Step 6: Restore the parallel bit stream to the data block after the initial disturbance through parallel-to-serial conversion.

[0170] Step 7: Based on the bit encryption factor and the bit perturbation factor, remove the initial perturbation from the data block after the initial perturbation according to the bit encryption factor and perform traversal decryption to restore the data block stored in the leaf node.

[0171] Step 8: Based on the complete binary tree block structure and the hierarchical coding routing information stored in the non-leaf nodes, the data blocks stored in the leaf nodes are merged and restored to the original data according to the same preset rules as the channel sending end.

[0172] This embodiment quantifies the security performance of the transmission system by strictly calculating the key space of the encryption scheme, such as Figure 8 As shown in the figure, the key includes the initial value and control parameters of the Zhan-4D hyperchaotic system. If the step size is set to 0.001, through the sensitivity test experiment, it can be obtained by adding 1×10 -N To strictly calculate the key space, and then conduct experiments to test whether the correct data can be successfully demodulated. Adjust the size of N until the node with high bit error rate and an order of magnitude difference from complete demodulation is the key space. Then the key space can be calculated experimentally as (10 17 ×10 17 ×10 17 ×10 17 ×10 16 ×10 15 ×10 15 ×10 15 ×10 15 ×10 15 ×10 15 ×10 14 ) × 10 3 =10 191Since the key space is large enough, even finding the correct key will take a long time, which effectively prevents hijackers from illegally obtaining the key.

[0173] Example 4

[0174] Based on the same inventive concept as other embodiments, this embodiment introduces a channel transmitter, including the following modules:

[0175] The data acquisition module is used to obtain the original data to be sent and the initial value of the key;

[0176] A factor generation module is used to synchronously generate four groups of chaotic sequences using a hyperchaotic system based on the initial value of the key, generate bit encryption factors and constellation encryption factors using two groups of chaotic sequences, and generate bit perturbation factors and constellation perturbation factors using the other two groups of chaotic sequences;

[0177] A data construction module is used to divide the original data to be sent into an even number of data blocks according to a preset rule to construct a complete binary tree, wherein the leaf nodes store the data blocks and the non-leaf nodes store the hierarchically encoded routing information;

[0178] A primary encryption module, configured to perform first-pass encryption and primary perturbation on a data block using the bit encryption factor based on the bit encryption factor and the bit perturbation factor;

[0179] A time-frequency conversion module is used to convert the primary perturbed data block into a parallel bit stream through serial-to-parallel conversion;

[0180] A secondary encryption module, configured to perform QAM mapping on the parallel bit streams based on the constellation encryption factor and the constellation perturbation factor, and perform a second traversal encryption and secondary perturbation according to the constellation perturbation factor;

[0181] A signal conversion module, used for converting the parallel bit stream after the secondary disturbance into a serial signal through a discrete Fresnel inverse transform matrix and parallel-to-serial conversion;

[0182] The frequency conversion processing module is used to perform up-conversion processing on the serial signal and transmit it to the transmission channel.

[0183] The specific functional implementation of each of the above modules can be found in the relevant contents of the method in Example 1 or Example 3 and will not be elaborated on here.

[0184] Example 5

[0185] Based on the same inventive concept as other embodiments, this embodiment introduces a channel receiving end, including the following modules:

[0186] The data acquisition module is configured to receive the up-converted serial signal in the transmission channel and generate four groups of chaotic sequences identical to those of the channel sending end based on the same key initial value as that of the channel sending end by using the hyper-chaotic system synchronization.

[0187] The factor generation module is configured to generate a bit encryption factor and a constellation encryption factor by using two groups of chaotic sequences, and generate a bit disturbance factor and a constellation disturbance factor by using the other two groups of chaotic sequences.

[0188] The frequency inverse processing module is configured to perform down-conversion processing on the up-converted serial signal to restore it to a serial signal.

[0189] The signal inverse conversion module is configured to restore the serial signal to a parallel bit stream after secondary disturbance by serial-parallel conversion and a discrete Fresnel transform matrix.

[0190] The secondary decryption module is configured to perform QAM inverse mapping on the parallel bit stream based on the constellation encryption factor and the constellation disturbance factor, and perform second traversal decryption and secondary disturbance according to the constellation disturbance factor.

[0191] The time-frequency inverse conversion module is configured to restore the parallel bit stream to a data block after primary disturbance by parallel-serial conversion.

[0192] The primary decryption module is configured to remove the primary disturbance and perform traversal decryption to restore the data block after primary disturbance to the data block stored in the leaf node based on the bit encryption factor and the bit disturbance factor according to the bit encryption factor.

[0193] The data reconstruction module is configured to combine and restore the data block stored in the leaf node to the original data according to the same preset rule as that of the channel sending end based on the hierarchical encoding routing information stored in the non-leaf node according to the complete binary tree block structure.

[0194] The up-converted serial signal is obtained by the signal transmission method of the first aspect.

[0195] The specific function implementation of each module is described in the related content of the method of Embodiment 2 or Embodiment 3, and is not repeated here.

[0196] In summary, the present invention utilizes a complete binary tree-based hierarchical architecture at the channel transmitter end to store hierarchically encoded routing information in non-leaf nodes, effectively reducing the path complexity of data block traversal encryption. Furthermore, a hyperchaotic sequence is used to generate bit encryption factors and constellation perturbation factors, utilizing two independent traversal encryptions to significantly enhance resistance to malicious eavesdropping and information tampering. Furthermore, the introduction of a discrete inverse Fresnel transform matrix further optimizes the signal spectrum characteristics, enhancing the system's security level while maintaining high anti-interference performance. This makes it suitable for the high confidentiality requirements of broadcast transmission scenarios such as passive optical networks, addressing the inadequate security protection issues faced by existing technologies in practical applications.

[0197] At the receiving end of the channel, the present invention uses a hierarchical architecture based on a complete binary tree, storing hierarchically encoded routing information in non-leaf nodes. This ensures that leaf node data blocks are accurately merged at the receiving end according to pre-set rules consistent with those at the transmitting end, reducing data reconstruction complexity and bit error rate. A hyperchaotic sequence is used to generate bit encryption factors and constellation perturbation factors, which are then decrypted using two independent traversals. This process is completely inversely aligned with the encryption process at the transmitting end, significantly improving robustness against noise interference and malicious attacks. Furthermore, the introduction of a discrete Fresnel transform matrix further optimizes signal spectrum recovery accuracy through a strict correspondence with the inverse transform. This reduces the system's security synchronization error rate while maintaining high demodulation efficiency, making it suitable for high-reliability reception requirements in broadcast transmission scenarios such as passive optical networks. Those skilled in the art will appreciate that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention 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-ROMs, optical storage, etc.) containing computer-usable program code.

[0198] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes 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 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 flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0199] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work 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 The function specified in one or more boxes.

[0200] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps for the function specified in one or more boxes.

[0201] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all protected by the present invention.

Claims

1. A signal transmission method, characterized in that: Executed by the channel sender, including: Get the original data and initial key value to be sent; Based on the initial value of the key, four groups of chaotic sequences are synchronously generated using a hyperchaotic system; Four groups of chaotic sequences are used to generate bit encryption factor, bit perturbation factor, constellation encryption factor and constellation perturbation factor respectively; Divide the original data to be sent into an even number of data blocks according to a preset rule to construct a complete binary tree, where leaf nodes store data blocks and non-leaf nodes store hierarchically encoded routing information; Based on the bit encryption factor and the bit perturbation factor, performing first-pass encryption and primary perturbation on the data block using the bit encryption factor; Converting the primary perturbed data block into a parallel bit stream through serial-to-parallel conversion; Based on the constellation encryption factor and the constellation perturbation factor, QAM mapping is performed on the parallel bit streams and second-pass encryption and secondary perturbation are performed according to the constellation perturbation factor; Converting the parallel bit stream after the secondary disturbance into a serial signal through the discrete Fresnel inverse transform matrix and parallel-to-serial conversion; The serial signal is up-converted and transmitted to the transmission channel.

2. The signal transmission method according to claim 1, wherein: The hyperchaotic system includes a Zhan-4D hyperchaotic system, and the Zhan-4D hyperchaotic system is expressed as: ； Where, Represents the state variables of the Zhan-4D hyperchaotic system on the horizontal axis The first derivative of Represents the state variables of the Zhan-4D hyperchaotic system on the vertical axis The first derivative of Represents the state variables of the vertical axis of the Zhan-4D hyperchaotic system The first derivative of represents the state feedback control parameters of the Zhan-4D hyperchaotic system The first derivative of represents the first system parameter of the Zhan-4D hyperchaotic model, represents the second system parameter of the Zhan-4D hyperchaotic model, represents the third system parameter of the Zhan-4D hyperchaotic model, represents the fourth system parameter of the Zhan-4D hyperchaotic model, represents the fifth system parameter of the Zhan-4D hyperchaotic model, represents the sixth system parameter of the Zhan-4D hyperchaotic model, represents the seventh system parameter of the Zhan-4D hyperchaotic model, represents the eighth system parameter of the Zhan-4D hyperchaotic model, where 、 、 、 、 、 、 and Jointly control the chaotic behavior of the Zhan-4D hyperchaotic system.

3. The signal transmission method according to claim 2, wherein: Four groups of chaotic sequences are used to generate bit encryption factors, bit perturbation factors, constellation encryption factors and constellation perturbation factors, including: ； Where, represents the bit encryption factor, represents the bit perturbation factor, represents the constellation encryption factor, represents the constellation perturbation factor, Represents the remainder operation, represents an arithmetic function that rounds toward negative infinity, represents the first chaotic sequence among the four chaotic sequences, represents the second chaotic sequence among the four chaotic sequences, represents the third chaotic sequence among the four chaotic sequences, Represents the fourth chaotic sequence among the four groups of chaotic sequences.

4. The signal transmission method according to claim 1, wherein: Also includes: Perform the following recursive operations on the data block stored in each leaf node of the complete binary tree: Divide the current data block into an even number of sub-data blocks according to the same preset rule; Construct a corresponding complete binary tree for each sub-data block as a sub-complete binary tree; The recursion stops until the data block reaches a minimum granularity, where the minimum granularity is a bit data stream.

5. The signal transmission method according to claim 4, wherein: The primary disturbance or secondary disturbance includes: At each recursive level of the complete binary tree, a preset perturbation algorithm is executed on the current sub-complete binary tree to perform independent perturbation processing.

6. The signal transmission method according to claim 1, wherein: Methods for traversing the data block include: pre-order traversal, in-order traversal, post-order traversal and level traversal.

7. A signal receiving method, characterized in that: Executed by the receiving end of the channel, including: The serial signal after up-conversion processing in the transmission channel is received and based on the same initial key value as the channel transmitting end, four groups of chaotic sequences identical to those at the channel transmitting end are synchronously generated by using a hyperchaotic system; Two sets of chaotic sequences are used to generate bit encryption factors and constellation encryption factors; Using another two groups of chaotic sequences to generate bit perturbation factors and constellation perturbation factors; Performing down-conversion processing on the serial signal after up-conversion processing to restore it to a serial signal; The serial signal is restored to a parallel bit stream after quadratic perturbation through serial-to-parallel conversion and discrete Fresnel transformation matrix; Based on the constellation encryption factor and the constellation perturbation factor, the parallel bit streams are de-QAM mapped and decrypted for the second time and perturbed again according to the constellation perturbation factor; Restore the parallel bit stream to the data block after the initial disturbance through parallel-to-serial conversion; Based on the bit encryption factor and the bit perturbation factor, the data block after the initial perturbation is removed according to the bit encryption factor and traversed decryption is performed to restore the data block stored in the leaf node; According to the complete binary tree block structure, based on the hierarchical coding routing information stored in non-leaf nodes, the data blocks stored in the leaf nodes are merged and restored to the original data according to the same preset rules as the channel sending end.

8. The signal receiving method according to claim 7, wherein: The discrete Fresnel transform matrix is ​​expressed as: ； Where, represents the Fresnel transform The first Rank The modulation signal of represents the number of chirp subcarriers, represents a vector, Represents the remainder operation.

9. A channel transmitting end, characterized in that: Includes the following modules: The data acquisition module is used to obtain the original data to be sent and the initial value of the key; A factor generation module is used to synchronously generate four sets of chaotic sequences using a hyperchaotic system based on the initial value of the key; two sets of chaotic sequences are used to generate bit encryption factors and constellation encryption factors, and the other two sets of chaotic sequences are used to generate bit perturbation factors and constellation perturbation factors; A data construction module is used to divide the original data to be sent into an even number of data blocks according to a preset rule to construct a complete binary tree, wherein the leaf nodes store the data blocks and the non-leaf nodes store the hierarchically encoded routing information; A primary encryption module, configured to perform first-pass encryption and primary perturbation on a data block using the bit encryption factor based on the bit encryption factor and the bit perturbation factor; A time-frequency conversion module is used to convert the primary perturbed data block into a parallel bit stream through serial-to-parallel conversion; A secondary encryption module, configured to perform QAM mapping on the parallel bit streams based on the constellation encryption factor and the constellation perturbation factor, and perform a second traversal encryption and secondary perturbation according to the constellation perturbation factor; A signal conversion module, used for converting the parallel bit stream after the secondary disturbance into a serial signal through a discrete Fresnel inverse transform matrix and parallel-to-serial conversion; The frequency conversion processing module is used to perform up-conversion processing on the serial signal and transmit it to the transmission channel.

10. A channel receiving end, characterized in that: Includes the following modules: The data acquisition module is used to receive the serial signal after up-conversion processing in the transmission channel and synchronously generate four groups of chaotic sequences identical to those at the channel transmitting end using a hyperchaotic system based on the same initial key value as that at the channel transmitting end; A factor generation module, configured to generate a bit encryption factor and a constellation encryption factor using two sets of chaotic sequences, and to generate a bit perturbation factor and a constellation perturbation factor using another two sets of chaotic sequences; The frequency conversion inverse processing module is used to perform down-conversion processing on the serial signal after up-conversion processing and restore it to a serial signal; A signal inverse conversion module is used to restore the serial signal to a parallel bit stream after quadratic perturbation through serial-to-parallel conversion and discrete Fresnel transformation matrix; A secondary decryption module, configured to perform QAM inverse mapping on the parallel bit stream based on the constellation encryption factor and the constellation perturbation factor, and perform a second traversal decryption and secondary perturbation according to the constellation perturbation factor; A time-frequency inverse conversion module is used to restore the parallel bit stream to the data block after the initial disturbance through parallel-to-serial conversion; A primary decryption module is used to remove the initial disturbance from the data block after the initial disturbance based on the bit encryption factor and perform traversal decryption to restore the data block stored in the leaf node; A data reconstruction module is used to restore the data blocks stored in the leaf nodes to the original data according to the same preset rules as the channel sending end based on the hierarchical coding routing information stored in the non-leaf nodes according to the complete binary tree block structure; Wherein, the serial signal after up-conversion processing is obtained by the signal transmission method according to any one of claims 1 to 6.

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