A terahertz transmission method and device integrated with sensing and chaos encryption enhancement

Abstract

The application discloses a chaos encryption enhanced terahertz transmission method and device, and relates to the technical field of communication. The method comprises the following steps: a transmitting end generates a chaos sequence by using a multi-direction offset enhanced three-dimensional chaos system, performs bit masking, constellation point permutation and rotation encryption on multi-channel communication data, so that the signal presents a noise-like characteristic and physical layer protection is realized; the encrypted multi-channel signal is linearly superimposed in a power domain through non-orthogonal multiple access, and the access capacity of a unit time-frequency resource is doubled; then, the superimposed encrypted signal is embedded in a free time-frequency area of a linear frequency modulation signal, so that a large time-bandwidth product of a radar is maintained and a transmission-sensing integrated baseband signal is formed; and the baseband signal is modulated by photons and subjected to optical heterodyne beat frequency to generate a terahertz waveform for emission. A receiving end separates multi-channel signals layer by layer by using serial interference cancellation, and original data is recovered by using a chaos key for decryption, and a radar module obtains target sensing information through matched filtering. The application realizes high security and large capacity fusion at a physical layer.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and more specifically to a chaotic encryption-enhanced terahertz inductive integrated transmission method and apparatus. Background Technology

[0002] With the full commercialization of 5G mobile communication, the global academic and industrial communities have shifted their research focus to 6G mobile communication. Integrated communication and sensing, as a core technology supporting emerging applications such as intelligent transportation, digital twins, and the low-altitude economy, has received widespread attention. The terahertz band, with its abundant spectrum resources, is considered an effective means to overcome current spectrum bottlenecks and achieve ultra-high-speed communication and high-precision sensing. However, traditional electronic terahertz technology faces severe hardware power consumption and speed bottlenecks when realizing ultra-wideband signal processing, while photonic terahertz technology, with its advantages of large bandwidth and low loss, provides a new path for the realization of integrated communication and sensing systems.

[0003] In existing integrated sensing waveform design schemes, while time-division multiplexing (TDM) or frequency-division multiplexing (FDM) based sensing fusion waveforms have low algorithm complexity and are easy to implement, they have inherent physical limitations: TDM inevitably reduces the time width of the sensed signal, while FDM compresses the effective bandwidth of the sensed signal, making it difficult for the system to meet the urgent need for a large time-bandwidth product in high-resolution detection. Furthermore, while using the linear frequency modulation (LFM) signal's frequency to embed multiple subcarrier communication signals within idle time-frequency resources can maintain the radar's original large time-bandwidth product characteristics to some extent, traditional orthogonal access methods are limited by finite subcarrier resources when facing future scenarios with massive terminal access, making it difficult to further improve the system's access capacity and throughput.

[0004] On the other hand, since sensing signals carry communication data while detecting the environment, and terahertz signals are highly susceptible to eavesdropping or interception by unauthorized nodes during line-of-sight transmission, relying solely on traditional high-layer network encryption protocols not only introduces additional latency, making it difficult to meet the stringent requirements of 6G ultra-low latency, but also fails to effectively defend against malicious attacks targeting physical layer waveform characteristics. Therefore, how to achieve a significant increase in communication access capacity while maintaining the high-resolution sensing characteristics of radar, and how to build an inherent security protection mechanism at the physical layer, has become a key technical problem that urgently needs to be solved in the field of integrated sensing research. Summary of the Invention

[0005] The purpose of this invention is to provide a terahertz sensing integrated transmission method and device enhanced with chaotic encryption. By deeply integrating chaotic encryption with non-orthogonal multiple access (NOA) technology, a sensing integrated transmission with both high security and large capacity is achieved. At the transmitting end, chaotic sequences are used to encrypt and scramble multiple communication data, making the signals exhibit noise-like characteristics. This blocks waveform interception and information theft by illegal nodes at the physical layer, overcoming the shortcomings of traditional high-level encryption protocols, such as large latency and inability to defend against physical layer attacks. Simultaneously, by linearly superimposing multiple encrypted signals in the power domain through NOA, the limitation of orthogonal access on subcarrier resources is broken, significantly increasing the communication access capacity and system throughput per unit time-frequency resource. The superimposed encrypted signal is precisely embedded into the idle time-frequency trajectory of the linear frequency modulated signal, maintaining the large time-bandwidth product and high range resolution required for radar sensing while achieving deep spectrum sharing between communication and sensing. At the receiving end, serial interference cancellation and chaotic key matching are used, ensuring that only legitimate receivers can recover the original data layer by layer from the mixed signal, guaranteeing inherently secure communication in open channels.

[0006] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, the present invention provides a chaotic encryption-enhanced terahertz sensing integrated transmission method, the method comprising: By using chaotic sequences generated by a chaotic system, multiple channels of raw communication data to be transmitted are encrypted to obtain multiple encrypted signals. Multiple encrypted signals are accessed through a non-orthogonal multiple access processing network. Power weights are allocated according to the channel gain of each encrypted signal, and they are linearly superimposed in the power domain to obtain a superimposed encrypted signal. The superimposed encrypted signal is embedded into the idle time-frequency resources of the linear frequency modulated signal to form an integrated inductive baseband signal; wherein, the idle time-frequency resources are the region outside the linear scanning trajectory of the frequency of the linear frequency modulated signal on the time-frequency plane. The integrated sensing baseband signal is modulated onto the optical carrier through a photonic terahertz conversion path, and a terahertz integrated sensing waveform is generated using optical heterodyne beat frequency, which is then transmitted into free space via an antenna. At the receiving end, the communication receiving module uses serial interference cancellation technology to separate and demodulate the received terahertz integrated induction signal into multiple layers, and uses the chaotic key generated by the chaotic system to decrypt the separated signals and recover the original communication data. The radar receiving module uses a reference signal to perform matched filtering on the received terahertz sensing integrated signal to obtain target perception information.

[0007] In some embodiments, the step of encrypting multiple streams of raw communication data to be transmitted using chaotic sequences generated by a chaotic system specifically includes: A chaotic sequence is generated using a multi-directional migration-enhanced three-dimensional chaotic system; the equation parameters of the chaotic system are set to put the multi-directional migration-enhanced three-dimensional chaotic system into a chaotic state. By performing at least one of the following operations on the original communication data using chaotic sequences: bit masking, constellation point permutation, and constellation point rotation, a multi-channel encrypted signal can be obtained.

[0008] In some embodiments, bit masking processing includes: The first set of initial values ​​is input into the multi-directional offset enhanced three-dimensional chaotic system and iterated to obtain the first chaotic sequence and the second chaotic sequence. The first chaotic sequence and the second chaotic sequence are processed to generate a position sequence indicating the position of the bit data to be inserted, and a masking information sequence representing the masking information to be inserted. Based on the position sequence, the masking information sequence is inserted into the corresponding position in the original communication data.

[0009] In some embodiments, constellation point replacement processing includes: The second set of initial values ​​is input into the multi-directional offset enhanced three-dimensional chaotic system and iterated to obtain the third chaotic sequence; The third chaotic sequence is converted into an integer sequence, and this integer sequence is used as an index sequence to scramble the constellation points obtained after constellation mapping.

[0010] In some embodiments, constellation point rotation processing includes: The third set of initial values ​​is input into the multi-directional offset enhanced three-dimensional chaotic system and iterated to obtain the fourth chaotic sequence; Generate constellation phase scrambling factors with random values ​​based on the fourth chaotic sequence; By using the constellation phase scrambling factor, a phase rotation operation is performed on the constellation points after constellation mapping to obtain the rotated encrypted constellation points.

[0011] In some embodiments, the steps of accessing multiple encrypted signals through a non-orthogonal multiple access processing network, allocating power weights based on the channel gain of each encrypted signal, and linearly superimposing them in the power domain specifically include: The channel gains of each encrypted signal are sorted, and different power weights are assigned to each encrypted signal according to the channel gain, with the signal with the lower channel gain being assigned a higher power weight. The encrypted signals, after being assigned power weights, are linearly superimposed in the power domain to form a superimposed encrypted signal that is multiplexed in the power domain.

[0012] Secondly, the present invention also provides a chaotic encryption-enhanced terahertz sensing integrated transmission device, the device comprising: The encryption processing module is used to encrypt multiple channels of raw communication data to be transmitted using chaotic sequences generated by a chaotic system, thereby obtaining multiple encrypted signals. The linear superposition module is used to access the processing network through a non-orthogonal multiple access (NOMA) to multiple encrypted signals, allocate power weights according to the channel gain of each encrypted signal, and perform linear superposition in the power domain to obtain a superimposed encrypted signal. The signal embedding module is used to embed the superimposed encrypted signal into the idle time-frequency resources of the linear frequency modulated signal to form an integrated inductive baseband signal; wherein, the idle time-frequency resources are the region outside the linear scanning trajectory of the frequency of the linear frequency modulated signal on the time-frequency plane; The signal transmission module is used to modulate the integrated sensing baseband signal onto the optical carrier through the photonic terahertz conversion path, and to generate a terahertz integrated sensing waveform using optical heterodyne beat frequency, which is then transmitted to free space via an antenna. The communication receiving module is used at the receiving end to separate and demodulate the received terahertz integrated induction signal using serial interference cancellation technology, and to decrypt the separated signals using the chaotic key generated by the chaotic system to recover the original communication data. The matched filtering module is used by the radar receiving module to perform matched filtering on the received terahertz sensing integrated signal using a reference signal to obtain target perception information.

[0013] Thirdly, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the chaotic encryption-enhanced terahertz inductive integrated transmission method provided in the first aspect.

[0014] Fourthly, the present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the chaotic encryption-enhanced terahertz inductive integrated transmission method provided in the first aspect.

[0015] Fifthly, the present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the chaotic encryption-enhanced terahertz inductive integrated transmission method provided in the first aspect.

[0016] The beneficial effects of this invention are as follows: By deeply integrating chaotic encryption with non-orthogonal multiple access (NOA) technology, this invention achieves integrated sensing transmission that combines high security and large capacity. At the transmitting end, chaotic sequences are used to encrypt and scramble multiple communication data, making the signals exhibit noise-like characteristics. This physically blocks waveform interception and information theft by unauthorized nodes, overcoming the shortcomings of traditional high-level encryption protocols, such as large latency and inability to defend against physical layer attacks. Simultaneously, by linearly superimposing multiple encrypted signals in the power domain through NOA, the limitations of orthogonal access on subcarrier resources are broken, significantly increasing the communication access capacity and system throughput per unit time-frequency resource. The superimposed encrypted signal is precisely embedded into the idle time-frequency trajectory of the linear frequency modulated signal, maintaining the large time-bandwidth product and high range resolution required for radar sensing while achieving deep spectrum sharing between communication and sensing. At the receiving end, serial interference cancellation and chaotic key matching ensure that only legitimate receivers can recover the original data layer by layer from the mixed signal, guaranteeing inherently secure communication in open channels.

[0017] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating a chaotic encryption-enhanced terahertz inductive integrated transmission method according to an embodiment of the present invention. Figure 2 This is a phase space diagram of a chaotic system according to an embodiment of the present invention; Figure 3 This is a bit masking diagram shown in one embodiment of the present invention; Figure 4 This is a constellation point permutation diagram according to an embodiment of the present invention; Figure 5 This is a constellation point rotation diagram shown in an embodiment of the present invention; Figure 6 This is a schematic diagram of the transmission bit error rate curve under the condition of eavesdropping, according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the structure of a chaotic encryption-enhanced terahertz inductive integrated transmission device according to an embodiment of the present invention. Figure 8 This is a schematic diagram of an electronic device structure provided in an embodiment of this application. Detailed Implementation

[0019] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] It should be noted that references to "an embodiment," "embodiment," "example embodiment," etc., in this specification refer to the described embodiment including specific features, structures, or characteristics; however, not every embodiment must include these specific features, structures, or characteristics. Furthermore, such expressions do not refer to the same embodiment. Moreover, when describing specific features, structures, or characteristics in conjunction with embodiments, whether or not explicitly described, it is indicated that incorporating such features, structures, or characteristics into other embodiments is within the knowledge of those skilled in the art.

[0021] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0022] In some embodiments, such as Figure 1 The diagram shows a flowchart of a chaotic encryption-enhanced terahertz sensing-integrated transmission method, the specific method of which includes: S101 uses the chaotic sequence generated by the chaotic system to encrypt multiple channels of original communication data to be transmitted, thereby obtaining multiple encrypted signals.

[0023] In the initial baseband processing at the transmitting end, the first challenge is to transform multiple raw communication data streams into multiple encrypted signals with anti-interception capabilities. The chaotic system used here is a nonlinear dynamical system whose extreme sensitivity to the initial state can generate long-term unpredictable noise-like sequences, making it an ideal carrier for physical layer signal masking. This embodiment specifically employs a multi-directional offset-enhanced three-dimensional chaotic system to generate the required chaotic sequence. By introducing nonlinear terms and complexity control constants, this system can generate more complex singular attractors than traditional low-dimensional systems. The equations of this chaotic model are shown below: ; Where t represents time, the above is the partial differential equation for time t, with the numbers set as a=0.6, b=2, c=3, m=2, n=6, p1=0.6, p2=1.8, p3=2.4, p=15. The system will be in a chaotic state. The initial values ​​are set in the range [-10, 10]. The phase space diagram of the chaotic system is as follows. Figure 2 As shown, Figure 2The attractor trajectory of the system in phase space is shown, exhibiting highly nonlinear folding and stretching characteristics, intuitively illustrating the strong randomness of the sequence. When the system equation parameters are set to induce a chaotic state, the system outputs three sets of chaotic sequences with high spectral entropy values, which are used for subsequent bit masking, constellation point permutation, and constellation point rotation operations, respectively.

[0024] S102, the multiple encrypted signals are accessed through a non-orthogonal multiple access processing network, power weights are allocated according to the channel gain of each encrypted signal, and they are linearly superimposed in the power domain to obtain a superimposed encrypted signal.

[0025] Bit masking refers to inserting additional masking information into the original data stream at positions indicated by a chaotic sequence, thereby disrupting the statistical regularity of the original bits. For example... Figure 3 The bit masking diagram shown is used to iterate through the three-dimensional chaotic system by taking the first set of initial values ​​(containing two independently set initial values) during execution, generating a first chaotic sequence x1 and a second chaotic sequence x2. By performing floor and modulo operations on these two sequences, a position sequence is derived from the first chaotic sequence to indicate which bits in the original data will be modified; a masking information sequence is derived from the second chaotic sequence and directly used as the bit value to be inserted. The processing formula is as follows: ; Here, floor represents the floor function, mod is the modulo function, in the two new sequences x' and x'', x' is the position information, which identifies the position of the bit data to be inserted, and x'' represents the masking information sequence to be inserted. Inserting the x'' sequence into the encoded text completes the bit masking.

[0026] Subsequently, based on the index given by the position sequence, the elements of the masking information sequence are embedded one by one into the corresponding bits of the original communication data to form intermediate data that has undergone bit masking.

[0027] Constellation point permutation involves scrambling the positions of digitally modulated symbols on the complex plane, causing the constellation diagram to lose its original regular structure. Its operation combines... Figure 4 The explanation is as follows: The second set of initial values ​​is input into the chaotic system for iteration, resulting in a third chaotic sequence. The values ​​in this sequence are then converted into an integer index sequence through a rounding mapping. After the communication data completes the conventional orthogonal amplitude modulation mapping and generates a standard constellation point set, these constellation points are reordered using this integer index sequence. The original order is replaced with the order specified by the index, thus randomizing the positions of the constellation points that were originally laid out according to Gray code, resulting in a constellation diagram that appears as a random, scattered point.

[0028] Constellation point rotation further involves rotating each constellation point around the origin by a random angle, causing the signal envelope to completely lose its original modulation characteristics. For example... Figure 5 As shown, the third set of initial values ​​is input into the chaotic system iteratively to obtain the fourth chaotic sequence z. This sequence is then transformed linearly to generate a series of random phase angles, i.e., constellation phase scrambling factors. For each symbol S after constellation mapping, the following complex multiplication rotation operation is performed: ; Where θ is the corresponding scrambling factor, and S' represents the encrypted constellation points. The constellation points, which were originally neatly arranged on the right-angled grid, are transformed into multiple concentric rings around the origin after rotation, exhibiting a highly random, noise-like distribution.

[0029] The three processing methods mentioned above—bit masking, constellation point permutation, and constellation point rotation—can be flexibly combined according to security requirements. One method can be used alone, or multiple methods can be executed sequentially. Regardless of the combination, the final output multi-channel signals are encrypted into multi-channel encrypted signals. Because chaotic systems are extremely sensitive to initial values, only a legitimate receiver holding three sets of initial values ​​identical to those at the sender as keys can correctly inversely decode these operations at the receiver. This establishes an intrinsic security barrier at the physical waveform level, avoiding the additional processing latency introduced by traditional high-level encryption protocols and better meeting the ultra-low latency secure communication requirements of 6G scenarios.

[0030] After obtaining multiple encrypted signals, the next step is to efficiently multiplex these signals in the power domain to overcome the capacity limit of traditional orthogonal multiple access (OMA) in terms of the number of subcarriers. The non-orthogonal multiple access (NOMA) technology used here actively allocates differentiated power to different signals at the transmitting end, allowing them to be transmitted over the same resources at the same time and frequency, thereby increasing access density and total throughput. In practice, firstly, based on the channel gain information obtained from channel estimation, the channel gains of all signals are sorted. Then, according to the principle of allocating higher power to signals with lower channel quality, different power weighting factors are determined for each signal. For example, the signal with the lowest channel gain is assigned the highest transmit power weight, and the signal with the highest channel gain is assigned the lowest power weight, forming a power-decreasing allocation scheme. Next, in the digital baseband, the weighted encrypted signals are directly linearly superimposed, that is, the complex symbols of each signal are added at each sampling point to obtain a mixed signal, called the superimposed encrypted signal. By superimposing this power domain non-orthogonal superposition, multiple data streams that originally needed to be transmitted on multiple independent orthogonal time-frequency resources now share the same resource, thereby multiplying the number of communication accesses and the total system throughput within a unit time-frequency resource. This overcomes the inherent defects of time-division multiplexing reducing the sensing time bandwidth and frequency-division multiplexing compressing the effective sensing bandwidth.

[0031] S103 embeds the superimposed encrypted signal into the idle time-frequency resources of the linear frequency modulation signal to form an integrated inductive baseband signal.

[0032] Among them, the idle time-frequency resources are the regions outside the linear frequency modulation signal’s linear scanning trajectory over time on the time-frequency plane.

[0033] After generating the superimposed encrypted signal, the next crucial step is to integrate this signal with the radar sensing waveform to construct a truly integrated waveform. This embodiment uses a linear frequency modulated (LFM) signal as the radar reference waveform because its frequency increases linearly with time, forming a sloping scanning trajectory on the time-frequency plane. The area outside the trajectory represents idle time-frequency resources that can be utilized by communication signals without interfering with normal radar detection. When generating the integrated sensing baseband signal, a standard LFM signal with a time width of T and a bandwidth of B is first generated. Then, in the digitized time-frequency grid, the LFM signal is filled into the grid points corresponding to its instantaneous frequency trajectory, while the superimposed encrypted signal obtained in the previous step is filled into the remaining time-frequency grid cells not covered by the trajectory. Finally, the two signal data are added point by point to obtain the integrated sensing baseband signal. This operation allows the linear frequency modulated signal to retain the two key parameters that determine the radar range resolution and detection capability, namely the time width T and bandwidth B, without compromising its large time-width-bandwidth product characteristics. At the same time, it utilizes the idle time-frequency region to accommodate additional communication data streams, achieving deep spectrum sharing between communication and sensing while ensuring high-precision sensing.

[0034] S104 modulates the integrated sensing baseband signal onto the optical carrier through a photonic terahertz conversion path, and generates a terahertz integrated sensing waveform using optical heterodyne beat frequency, which is then transmitted into free space via an antenna.

[0035] After the baseband signal is generated, it needs to be shifted to the terahertz band and transmitted into free space. This embodiment utilizes a photonic terahertz conversion path to complete this frequency up-conversion process. Specifically, it uses photonics to modulate the electrical signal onto an optical carrier, and then generates a terahertz wave through optical heterodyne beat frequency. Specifically, the integrated sensing baseband analog signal is first input as a driving electrical signal to a dual parallel Mach-Zehnder modulator. This modulator modulates the intensity or phase of the coherent optical carrier from the first tunable laser, enabling it to carry sensing information. The output light wave is called the signal light. To compensate for the insertion loss generated during modulation and ensure sufficient transmission power, the signal light is fed into an erbium-doped fiber amplifier for optical power enhancement, and then its polarization state is adjusted by a polarization controller to achieve optimal beat frequency efficiency. Simultaneously, a second tunable laser generates a beam of light with a different frequency than the signal light as the local oscillator. The two beams are combined into a single beam in an optical coupler. The synthesized optical signal, with its total power precisely controlled by an adjustable optical attenuator, is then projected onto a terahertz transmitter, such as a photoconductive antenna or a single-row carrier photodiode. The transmitter utilizes the photoelectric conversion effect to respond to the frequency difference between the two beams. Since this frequency difference falls precisely in the terahertz band, a terahertz signal is generated with a carrier frequency of terahertz and an envelope containing a complete inductive waveform. This signal is ultimately radiated by a high-gain terahertz antenna. This photonic-assisted frequency conversion method fully leverages the wide bandwidth and low loss advantages of photonic devices, avoiding the power consumption and speed bottlenecks of traditional electronic terahertz sources in ultra-wideband processing.

[0036] After being transmitted via a wireless channel, the signal is captured by a terahertz signal receiver at the receiving end and down-converted to an intermediate frequency or baseband frequency, resulting in an integrated inductive signal at the receiving end. Subsequently, the communication receiving module and the radar receiving module process this signal in parallel.

[0037] S105, at the receiving end, the communication receiving module uses serial interference cancellation technology to separate and demodulate the received terahertz integrated induction signal into multiple layers, and uses the chaotic key generated by the chaotic system to decrypt each separated signal and recover the original communication data.

[0038] On the receiving side, because multiple signals are superimposed in the power domain, serial interference cancellation (FICCC) is required to separate them step by step. FICCC is a multi-user detection algorithm that first detects the strongest signal in the mixed signal, subtracts its contribution from the total signal after successful demodulation, and then repeats this process for the next strongest signal. In this embodiment, the receiver identifies the encrypted signal corresponding to the highest power weight based on the pre-negotiated power allocation factor and channel estimation, and uses a demodulator with the corresponding modulation scheme to determine the encrypted symbol for that layer. After determining one signal, the waveform of that signal component is reconstructed using the known power factor, channel response, and decision symbol, and then subtracted from the original received mixed signal to obtain a residual signal. The same process is then performed on the next highest power signal in the residual signal, and this cycle continues until the symbol of the weakest power signal is extracted. Each successfully separated encrypted signal immediately enters the decryption process. The decryption process is the reverse of the encryption at the transmitting end. The receiving end holds the exact same combination of chaotic initial values ​​as the transmitting end as its key, and can reproduce three identical sets of chaotic sequences: The first set of initial values ​​is used to generate the same position sequence and masking information sequence, completing the removal of bit masking; the second set of initial values ​​is used to generate the same integer index sequence, restoring the constellation points to their original regular arrangement; the third set of initial values ​​is used to generate the same phase scrambling factor sequence, performing a conjugate rotation on the constellation symbols to return them to their original constellation point positions. After this series of reverse operations, the communication data at each layer is restored to the error-free original data stream.

[0039] S106, the radar receiving module uses a reference signal to perform matched filtering on the received terahertz sensing integrated signal to obtain target perception information.

[0040] On the radar receiver side, the radar receiving module uses the same linear frequency modulated (LFM) signal as the transmitting signal as the reference signal to perform matched filtering, or pulse compression, on the received integrated communication and sensing signal. Matched filtering essentially involves convolving the received signal with the conjugate of the reference signal, mathematically equivalent to correlation reception of the echo signal. Because the superimposed encrypted signal is pre-defined within idle time-frequency resources outside the LFM signal trajectory, its correlation with the reference signal is extremely low. The pulse compression process naturally suppresses incoherent interference caused by the embedded communication signal. The compressed peak value accurately reflects the target's range and velocity information, thus obtaining precise target perception results without sacrificing the radar's high range resolution. At this point, the entire transceiver link completes high-capacity, high-security integrated terahertz communication and sensing transmission.

[0041] Figure 6The transmission error rate curves under the condition of eavesdropping are presented, where IOP is the input optical power and BER is the bit error rate. It can be seen that the bit error rate after decryption by the legitimate receiver is basically the same as that of unencrypted transmission, indicating that the encryption operation has no substantial impact on the communication quality. However, due to the lack of an accurate chaotic key, the bit error rate of the eavesdropper remains around 50%, which means that it is completely unable to obtain any useful information from the intercepted signal, further verifying the reliability of the physical layer security measures of this method.

[0042] Based on the same inventive concept, this application also provides a chaotic encryption-enhanced terahertz sensing integrated transmission device for implementing the chaotic encryption-enhanced terahertz sensing integrated transmission method described above. The solution provided by this device is similar to the implementation described in the above method; therefore, the specific limitations of one or more chaotic encryption-enhanced terahertz sensing integrated transmission device embodiments provided below can be found in the limitations of the chaotic encryption-enhanced terahertz sensing integrated transmission method described above, and will not be repeated here.

[0043] In one embodiment, such as Figure 7 As shown, a chaotic encryption-enhanced terahertz sensing integrated transmission device is provided, the device comprising: The encryption processing module 30 is used to encrypt multiple channels of original communication data to be transmitted using the chaotic sequence generated by the chaotic system, so as to obtain multiple encrypted signals. The linear superposition module 31 is used to access the processing network through a non-orthogonal multiple access network to process multiple encrypted signals, allocate power weights according to the channel gain of each encrypted signal, and perform linear superposition in the power domain to obtain superimposed encrypted signals. The signal embedding module 32 is used to embed the superimposed encrypted signal into the idle time-frequency resources of the linear frequency modulated signal to form a syn-inductive integrated baseband signal; wherein, the idle time-frequency resources are the region outside the linear scanning trajectory of the frequency of the linear frequency modulated signal on the time-frequency plane; The signal transmission module 33 is used to modulate the integrated sensing baseband signal onto the optical carrier through the photonic terahertz conversion path, and generate a terahertz integrated sensing waveform using optical heterodyne beat frequency, and transmit it into free space through the antenna; The communication receiving module 34 is used at the receiving end to perform multi-level signal separation and demodulation of the received terahertz integrated induction signal using serial interference cancellation technology, and to decrypt the separated signals using the chaotic key generated by the chaotic system to recover the original communication data. The matched filtering module 35 is used by the radar receiving module to perform matched filtering on the received terahertz sensing integrated signal using a reference signal to obtain target perception information.

[0044] This application also provides an electronic device, in some embodiments, referring to... Figure 8 As shown, the electronic device 700 includes an input unit 710, a memory 720, a processor 730, and an output unit 740. The memory 720 stores program instructions that can be executed on the processor 730. The processor 730 can execute the terahertz sensing integrated transmission method and / or technical solution based on the chaotic encryption enhancement described in the foregoing embodiments by calling the program instructions. This electronic device 700 can be a mobile terminal device such as a mobile phone or computer.

[0045] Furthermore, embodiments of this application also provide a computer-readable storage medium for storing a computer program that executes a chaotic encryption-enhanced terahertz inductive integrated transmission method. For example, computer program instructions, when executed by a computer, can invoke or provide the methods and / or technical solutions according to this application through the operation of the computer. The program instructions that invoke the methods of this application may be stored in a fixed or removable storage medium, and / or transmitted via data streams in broadcast or other signal carrying media, and / or stored in a storage medium that operates according to the program instructions.

[0046] Obviously, those skilled in the art should understand that the modules or steps of this application described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Optionally, they can be implemented using computer-executable program code, thereby storing them in a storage device for execution by a computing device, or fabricating them separately as individual integrated circuit modules, or fabricating multiple modules or steps as a single integrated circuit module. Thus, this application is not limited to any particular combination of hardware and software.

[0047] The technical features of the above embodiments can be arbitrarily integrated. For the sake of brevity, not all possible integrations of the technical features in the above embodiments are described. However, as long as the integration of these technical features does not contradict each other, they should be considered to be within the scope of this specification.

[0048] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for terahertz sensing and communication integration with chaos encryption enhancement, characterized in that, The method includes: By using chaotic sequences generated by a chaotic system, multiple channels of raw communication data to be transmitted are encrypted to obtain multiple encrypted signals. The multiple encrypted signals are accessed through a non-orthogonal multiple access processing network, and power weights are allocated according to the channel gain of each encrypted signal. The signals are then linearly superimposed in the power domain to obtain a superimposed encrypted signal. The superimposed encrypted signal is embedded into the idle time-frequency resources of the linear frequency modulated signal to form an integrated inductive baseband signal; wherein, the idle time-frequency resources are the region outside the linear scanning trajectory of the frequency of the linear frequency modulated signal on the time-frequency plane. The integrated sensing baseband signal is modulated onto an optical carrier through a photonic terahertz conversion path, and a terahertz integrated sensing waveform is generated using optical heterodyne beat frequency, which is then transmitted into free space via an antenna. At the receiving end, the communication receiving module uses serial interference cancellation technology to separate and demodulate the received terahertz integrated induction signal at multiple levels, and uses the chaotic key generated by the chaotic system to decrypt each separated signal to recover the original communication data. The radar receiving module uses a reference signal to perform matched filtering on the received terahertz sensing signal to obtain target perception information.

2. The chaos encryption enhanced terahertz sensing and communication integrated transmission method according to claim 1, characterized in that, The step of encrypting multiple channels of raw communication data to be transmitted using chaotic sequences generated by a chaotic system specifically includes: A chaotic sequence is generated using a multi-directional offset enhanced three-dimensional chaotic system; the equation parameters of the chaotic system are set to put the multi-directional offset enhanced three-dimensional chaotic system into a chaotic state. The chaotic sequence is used to perform at least one of the following operations on the original communication data: bit masking, constellation point permutation, and constellation point rotation, to obtain the multi-channel encrypted signal.

3. The chaos encryption enhanced terahertz sensing and communication integrated transmission method according to claim 2, characterized in that, The bit masking process includes: The first set of initial values ​​is input into the multi-directional offset enhanced three-dimensional chaotic system for iteration, resulting in a first chaotic sequence and a second chaotic sequence. The first chaotic sequence and the second chaotic sequence are processed to generate a position sequence indicating the position of the bit data to be inserted, and a masking information sequence representing the masking information to be inserted. Based on the location sequence, the masking information sequence is inserted into the corresponding position in the original communication data.

4. The chaos encryption enhanced terahertz sensing and communication integrated transmission method according to claim 2, characterized in that, The constellation point replacement process includes: The second set of initial values ​​is input into the multi-directional offset enhanced three-dimensional chaotic system for iteration to obtain the third chaotic sequence; The third chaotic sequence is converted into an integer sequence, and this integer sequence is used as an index sequence to scramble the constellation points obtained after constellation mapping.

5. The chaos encryption enhanced terahertz sensing and communication integrated transmission method according to claim 2, characterized in that, The constellation point rotation process includes: The third set of initial values ​​is input into the multi-directional offset enhanced three-dimensional chaotic system for iteration to obtain the fourth chaotic sequence; Generate constellation phase scrambling factors with random values ​​based on the fourth chaotic sequence; The constellation points after constellation mapping are rotated using the constellation phase scrambling factor to obtain the rotated encrypted constellation points.

6. The chaos encryption enhanced terahertz sensing and communication integrated transmission method according to any one of claims 1 to 5, characterized in that, The steps of accessing and processing multiple encrypted signals through a non-orthogonal multiple access network, allocating power weights based on the channel gain of each encrypted signal, and linearly superimposing them in the power domain specifically include: The channel gains of each encrypted signal are sorted, and different power weights are assigned to each encrypted signal according to the channel gain, with the signal with the lower channel gain being assigned a higher power weight. The encrypted signals, after being assigned power weights, are linearly superimposed in the power domain to form a superimposed encrypted signal that is multiplexed in the power domain.

7. A chaos encryption enhanced terahertz sensing and communication integrated transmission device, characterized in that, The device includes: The encryption processing module is used to encrypt multiple channels of raw communication data to be transmitted using chaotic sequences generated by a chaotic system, thereby obtaining multiple encrypted signals. The linear superposition module is used to access the processing network through a non-orthogonal multiple access (NOMA) to multiple encrypted signals, allocate power weights according to the channel gain of each encrypted signal, and perform linear superposition in the power domain to obtain a superimposed encrypted signal. A signal embedding module is used to embed the superimposed encrypted signal into the idle time-frequency resources of the linear frequency modulated signal to form an integrated inductive baseband signal; wherein, the idle time-frequency resources are the region outside the linear scanning trajectory of the frequency of the linear frequency modulated signal on the time-frequency plane; The signal transmission module is used to modulate the integrated sensing baseband signal onto the optical carrier through a photonic terahertz conversion path, and generate a terahertz integrated sensing waveform using optical heterodyne beat frequency, which is then transmitted to free space via an antenna. The communication receiving module is used at the receiving end to separate and demodulate the received terahertz integrated induction signal using serial interference cancellation technology, and to decrypt the separated signals using the chaotic key generated by the chaotic system to recover the original communication data. The matched filtering module is used by the radar receiving module to perform matched filtering on the received terahertz sensing integrated signal using a reference signal to obtain target perception information.

8. An electronic device comprising a memory, a processor, and a computer program stored on the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the chaotic encryption-enhanced terahertz inductive integrated transmission method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the chaotic encryption-enhanced terahertz inductive integrated transmission method as described in any one of claims 1 to 6.

10. A computer program product comprising a computer program, characterized in that, When executed by a processor, the computer program implements the chaotic encryption-enhanced terahertz inductive integrated transmission method as described in any one of claims 1 to 6.

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