Cooperative interference secure transmission method and system based on transmissive and reflective integrated smart metasurface

Abstract

The application provides a kind of based on the cooperative jamming security transmission method and system of transmissive-reflection integrated smart surface, belongs to wireless communication technical field, the method includes: constructing security communication scene;In the security communication scene, transmissive-reflection integrated smart surface with the function of re-regulating incident signal into transmission signal or reflection signal is deployed, to divide the communication space into transmission space and reflection space;In different communication link scenes, combined with the cooperative jamming security transmission method, different security communication strategies are set;The communication performance key parameters of each security communication strategy are calculated and analyzed, to select the required security communication strategy according to actual demand.The application uses transmissive-reflection integrated smart surface to construct security communication scene that can not only guarantee communication efficiency but also effectively defend against eavesdropping attacks, not only enhances the security of communication system, but also provides an important idea for future intelligent, adaptive security communication network design.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a cooperative interference secure transmission method and system based on a transflective integrated intelligent metasurface. Background Technology

[0002] Smart metasurfaces, a hot technology in next-generation wireless communication, can improve spectral efficiency, energy efficiency, and physical layer security. Smart metasurfaces consist of numerous low-cost, passive, and reconfigurable components. Integrating a smart controller into the smart metasurface allows for the reconfiguration of incident signal propagation by altering the phase and amplitude of these reconfigurable elements, thus creating a smart radio environment. Published research has suggested that smart metasurfaces can only reflect incident signals; therefore, communication systems cannot use smart metasurfaces when the transmitter and receiver are on opposite sides of the surface. This limitation restricts the flexibility of smart metasurfaces and the coverage of communication. To address this issue, researchers have proposed a transflective-reflective integrated smart metasurface.

[0003] Unlike traditional smart metasurfaces, each unit of the transmissive-reflective integrated smart metasurface can split an incident signal into two parts: one part is reflected into a reflection space, and the other part is transmitted into a transmission space. Each unit of the transmissive-reflective integrated smart metasurface controls the transmitted and reflected signals through two independent coefficients: the transmission coefficient and the reflection coefficient. Therefore, the transmissive-reflective integrated smart metasurface can provide full-space communication coverage, offering new degrees of freedom for controlling signal propagation and increasing the flexibility of network design. In existing literature, the authors propose three practical transmissive-reflective integrated smart metasurface operation protocols: energy partitioning, mode switching, and time switching.

[0004] In next-generation wireless communication, hundreds of millions of IoT devices will emerge. However, due to the large number of wireless devices, frequent battery replacement / charging is often costly, and in many critical applications (such as artificial hearts), battery replacement and recharging are not even feasible. To address this issue, researchers have proposed wirelessly powered communication technology, which wirelessly transmits electrical energy via radio frequency signal payloads. This technology can provide a flexible, controllable, and on-demand energy supply for large-scale deployment of low-power IoT devices to support their sensing, computing, and communication functions. However, wirelessly powered communication itself also has drawbacks, such as low long-distance transmission efficiency and inter-device communication interference. Smart metasurfaces / transparent-reflective integrated smart metasurfaces can improve the energy transmission efficiency of wireless communication networks and enhance the quality of information transmission. Therefore, the use of smart metasurfaces / transparent-reflective integrated smart metasurfaces to improve the efficiency of energy harvesting and information transmission in wirelessly powered communication systems has attracted widespread attention from researchers.

[0005] On the other hand, the open nature of wireless transmission makes confidential and sensitive information easily exposed to malicious eavesdroppers. To defend against security attacks such as eavesdropping or interference, Wyner proposed the concept of physical layer security from an information theory perspective, which utilizes the inherent characteristics of wireless channels (e.g., noise, fading, and interference) to reduce the leakage of legitimate information. Simultaneously, because transflective-reflective integrated smart metasurfaces have the ability to reconfigure incident signals and reconstruct the communication environment, combining transflective-reflective integrated smart metasurfaces with physical layer security can effectively improve the security of communication systems. However, while transflective-reflective integrated smart metasurfaces enhance signal reception for legitimate receivers, they also improve the quality of eavesdropping signals. This problem can be addressed by introducing cooperative interference into wireless communication systems assisted by transflective-reflective integrated smart metasurfaces.

[0006] Current research primarily focuses on achieving secure physical layer transmission using integrated transflective / reflective smart metasurfaces / smart metasurface beamforming capabilities, with no inventions combining integrated transflective / reflective smart metasurfaces with cooperative jamming yet to be found. Furthermore, due to the unique operating mode of integrated transflective / reflective smart metasurfaces, security performance analysis of smart metasurface-assisted wireless power supply communication systems is not applicable to research on such systems. The impact of key system parameters on the reliability and security of integrated transflective / reflective smart metasurface-assisted wireless power supply communication systems remains unclear. Cooperative jamming strategies hold great potential in improving the security performance of integrated transflective / reflective smart metasurface-assisted wireless power supply communication systems, degrading the quality of signals received by eavesdroppers through existing wireless communication equipment without introducing additional jammers. Research on cooperative jamming secure communication in integrated transflective / reflective smart metasurface-assisted wireless power supply communication systems is currently lacking. Summary of the Invention

[0007] This invention provides a cooperative interference secure transmission method and system based on a transparent-reflective integrated intelligent metasurface. It studies the impact of key parameters on the system when different users communicate with different eavesdroppers, so as to select a suitable secure communication scheme.

[0008] In a first aspect, the present invention provides a method for secure transmission through cooperative interference based on a transmissive-reflective integrated intelligent metasurface, comprising: constructing a secure communication scenario; the secure communication scenario includes an access node, an energy base station, two legitimate users, and two eavesdroppers, wherein the two legitimate users are an outdoor user and an indoor user, and the two eavesdroppers are a first eavesdropper corresponding to the outdoor user and a second eavesdropper corresponding to the indoor user; deploying a transmissive-reflective integrated intelligent metasurface in the secure communication scenario, which has the function of remodulating incident signals into transmitted or reflected signals, to divide the communication space into a transmission space and a reflection space; the outdoor user, the energy base station, the access node, and the first eavesdropper are deployed in the reflection space, and the indoor user and the second eavesdropper are deployed in the transmission space; setting different secure communication strategies in combination with the cooperative interference secure transmission method under different communication link scenarios; the cooperative interference secure transmission method involves the indoor and outdoor users sending artificial noise to interfere with the eavesdropper's eavesdropping when one party is communicating; calculating and analyzing the key communication performance parameters of each secure communication strategy to select the required secure communication strategy according to actual needs; the key communication performance parameters include interruption probability, confidentiality interruption probability, and effective confidentiality throughput.

[0009] Secondly, the present invention also provides a cooperative interference secure transmission system based on a transparent-reflective integrated intelligent metasurface, comprising: an access node, an energy base station, two legitimate users, and two eavesdroppers, characterized in that a secure communication strategy is set by applying any of the aforementioned cooperative interference secure transmission methods based on a transparent-reflective integrated intelligent metasurface.

[0010] The cooperative interference secure transmission method and system based on a transflective integrated intelligent metasurface provided by this invention can achieve the following beneficial effects compared with the prior art:

[0011] (1) This invention utilizes a transparent-reflective integrated intelligent metasurface to construct a secure communication scenario that can both ensure communication efficiency and effectively defend against eavesdropping attacks. This not only enhances the security of the communication system but also provides important ideas for the design of future intelligent and adaptive secure communication networks. Furthermore, different secure communication strategies are designed under the secure communication scenario, and the impact of key communication performance parameters (such as interruption probability, confidentiality interruption probability, and effective confidentiality throughput) on the performance of the communication system is studied to select appropriate communication strategies as needed. (2) The cooperative interference strategy provided by this invention solves the disadvantage that while the transparent-reflective integrated intelligent metasurface enhances legitimate user communication, it also brings benefits to eavesdroppers. By introducing artificial noise to interfere with it, the confidentiality performance of the system is improved. (3) This invention lays the theoretical foundation for a secure communication method for wireless power supply systems assisted by a transparent-reflective integrated intelligent metasurface. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0013] Figure 1 This is a flowchart illustrating the cooperative interference secure transmission method based on a transflective integrated intelligent metasurface provided in an embodiment of the present invention.

[0014] Figure 2 This is a schematic diagram of secure transmission under different secure communication strategies in different communication link scenarios provided by embodiments of the present invention;

[0015] Figure 3 This is a schematic diagram illustrating the communication interruption probability of various strategies under different power levels, provided in an embodiment of the present invention.

[0016] Figure 4 This is a schematic diagram illustrating the probability of user communication interruption under different strategies and different numbers of unit reflective elements provided in an embodiment of the present invention;

[0017] Figure 5 This is a schematic diagram illustrating the probability of user confidentiality interruption under different strategies and power levels, provided by an embodiment of the present invention.

[0018] Figure 6 This is a schematic diagram illustrating the probability of user privacy interruption under different strategies and different numbers of units, provided in an embodiment of the present invention.

[0019] Figure 7 This is a schematic diagram of the effective confidentiality throughput of users under different strategies provided in the embodiments of the present invention;

[0020] Figure 8 This is a schematic diagram illustrating the effective confidential throughput of outdoor users with different numbers of units under different strategies, provided in an embodiment of the present invention.

[0021] Figure 9 This is a schematic diagram illustrating the effective confidential throughput of indoor users with different numbers of units under different strategies, provided by an embodiment of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0023] The following is combined Figures 1-9 This invention describes a method and apparatus for secure transmission of interference based on a transflective and reflective integrated intelligent metasurface, as provided in embodiments of the present invention.

[0024] Figure 1 This is a flowchart illustrating the cooperative interference secure transmission method based on a transflective integrated smart metasurface provided in an embodiment of the present invention, as shown below. Figure 1 As shown, including but not limited to the following steps:

[0025] Step 101: Construct a secure communication scenario; the secure communication scenario includes an access node, an energy base station, two legitimate users, and two eavesdroppers, wherein the two legitimate users are outdoor user U. r and indoor users U t The two eavesdroppers are the first eavesdropper E1, which corresponds to the outdoor user, and the second eavesdropper E2, which corresponds to the indoor user.

[0026] This invention constructs a complex communication environment with multiple roles, designed to simulate potential security challenges in the real world. Legitimate users (outdoor and indoor users) need to communicate securely under the presence of potential eavesdropping threats. The presence of two eavesdroppers corresponds to the communication threats to outdoor and indoor users respectively, requiring the security strategy to consider protection at different locations simultaneously.

[0027] Step 102: Deploy a smart metasurface that integrates transmission and reflection in the secure communication scenario to divide the communication space into a transmission space and a reflection space; outdoor users, energy base stations, access nodes and the first eavesdropper are deployed in the reflection space, and indoor users and the second eavesdropper are deployed in the transmission space.

[0028] The integrated transflective and reflective smart metasurface consists of N adjustable integrated transflective and reflective smart metasurface units. By deploying the integrated transflective and reflective smart metasurface, the communication link between outdoor and indoor users can be enhanced.

[0029] The integrated transmissive and reflective smart metasurface is an advanced physical layer security enhancement technology that can dynamically adjust incident wireless signals, converting them into transmitted or reflected signals, thereby enabling flexible partitioning of the communication space. This deployment strategy not only physically isolates different user groups (outdoor and indoor) but also provides a foundation for subsequent implementation of directional protection and jamming strategies.

[0030] The reflection space refers to the spatial region where signals emitted from the source reach the destination after being reflected by the integrated transmissive and reflective intelligent metasurface. In the constructed secure communication scenario, outdoor users, energy base stations, access nodes, and the first eavesdropper are deployed within the reflection space. Information and energy signals are transmitted between nodes within this space via reflection from the integrated transmissive and reflective intelligent metasurface. This design allows energy and information to propagate directionally within the space, achieving efficient, high-quality, and highly secure communication.

[0031] In contrast to reflection space, transmission space refers to the spatial region where a signal emitted from a source reaches the destination via transmission through an integrated reflective and transmissive intelligent metasurface. In the constructed secure communication scenario, indoor users and a second eavesdropper are deployed within the transmission space. The design intent is to allow certain communication links (such as from the access node to the indoor user) to utilize the transmission properties of the metasurface, increasing the freedom of signal design and achieving full-space communication coverage.

[0032] Step 103: In different communication link scenarios, combine the cooperative interference secure transmission method to set different secure communication strategies.

[0033] The method of coordinated interference secure transmission involves one indoor or outdoor user sending artificial noise to interfere with the eavesdropper's eavesdropping while the other is communicating. In this invention, the user who performs the coordinated interference is referred to as the coordinated interference user.

[0034] Optionally, when the outdoor user is communicating, the indoor user emits artificial noise based on a transparent and reflective integrated smart metasurface to interfere with the first eavesdropper.

[0035] Specifically, when outdoor users are communicating, to conserve spectrum resources, indoor users act as friendly interference nodes to disrupt the first eavesdropper, provided there are existing nodes. At this time, indoor users intelligently coordinate and emit artificial noise. Because indoor users are located in the transmission space, the noise they emit needs to be transmitted through a transmissive-reflective integrated intelligent metasurface phase-shift design to ensure that this noise, after passing through the metasurface and entering the reflection space, can effectively interfere with the first eavesdropper's reception. This mechanism utilizes the programmable characteristics of the metasurface to achieve omnidirectional interference, effectively disrupting eavesdroppers whose channel state information is unknown.

[0036] When indoor users are communicating, outdoor users can interfere with the first and second eavesdroppers based on the transparent and reflective integrated smart metasurface.

[0037] Specifically, when an indoor user communicates, both the first eavesdropper (located outdoors) and the second eavesdropper (located indoors) need to be interfered with. In this case, the outdoor user acts as the interference node, responsible for transmitting artificial noise. Since the outdoor user is in the same space as the first eavesdropper but in a different space from the second eavesdropper, to interfere with both eavesdroppers, each unit of the integrated transmissive-reflective intelligent metasurface always operates in simultaneous transmission and reflection mode through intelligent phase-shift control design. When the noise signal emitted by the outdoor user reaches the integrated transmissive-reflective intelligent metasurface, it is reflected by N units to achieve omnidirectional interference in the reflection space. Simultaneously, while ensuring that N1 units are used for indoor users to transmit information to the outdoor access node, the remaining N2 units transmit the noise emitted by the outdoor user into the indoor space, causing omnidirectional interference within the indoor space.

[0038] Step 104: Calculate and analyze the key communication performance parameters of each secure communication strategy to select the required secure communication strategy according to actual needs; the key communication performance parameters include interruption probability, confidentiality interruption probability, and effective confidentiality throughput.

[0039] Outage probability measures the likelihood of communication failure due to insufficient resources or interference; confidentiality outage probability focuses on the probability of communication security being compromised during hostile eavesdropping; effective confidentiality throughput represents the maximum data transmission rate that communication can achieve while ensuring information confidentiality. By comprehensively considering these parameters, the most suitable secure communication strategy can be selected according to the needs of specific application scenarios.

[0040] This invention requires the use of mathematical tools and simulation software (such as MATLAB) to accurately evaluate these indicators by establishing a specific channel model for the secure communication strategy and considering factors such as power allocation, coding strategy, and channel state information.

[0041] This invention utilizes a transparent-reflective integrated intelligent metasurface to construct a secure communication environment that can both ensure communication efficiency and effectively defend against eavesdropping attacks. This not only enhances the security of the communication system but also provides important ideas for the design of future intelligent and adaptive secure communication networks. Furthermore, different secure communication strategies were designed, and the impact of key communication performance parameters (such as interruption probability, confidentiality interruption probability, and effective confidentiality throughput) on the performance of the communication system was studied.

[0042] Figure 2 This is a schematic diagram of secure transmission under different secure communication strategies in different communication link scenarios provided by embodiments of the present invention. The following is in conjunction with... Figure 2 Further explanation of each secure communication strategy is provided.

[0043] This invention combines a cooperative interference secure transmission method with different secure communication strategies under different communication link scenarios: For scenario I, where the direct power supply link is blocked, two strategies are proposed: outdoor user information transmission and indoor user cooperative interference (IbTOJI) and outdoor user cooperative interference and indoor user information transmission (IbJOTI). For scenario II, where the direct information transmission link is blocked, two strategies are proposed: outdoor user information transmission and indoor user cooperative interference (IIbTOJI) and outdoor user cooperative interference and indoor user information transmission (IIbJOTI). In scenario III, where both the direct links for energy harvesting and information transmission are blocked, two strategies are proposed: outdoor user information transmission and indoor user cooperative interference (IIIbTOJI) and outdoor user cooperative interference and indoor user information transmission (IIIbJOTI). The operation of each secure communication strategy is divided into two stages: the energy harvesting stage and the information transmission stage. In the energy harvesting stage, U... r and U t Radio frequency (RF) energy from an energy base station is collected simultaneously over a time interval θT. The RF energy signal is reconstructed using the transmission and reflection coefficients of each transmissive-reflective integrated smart metasurface unit, and the incident signal energy is distributed directionally to legitimate users located in the transmission and reflection spaces according to the ratio of the transmission and reflection coefficients. The collected energy is then used to transmit a signal over a time interval of (1-θ)T. During the information transmission phase, when one user transmits confidential information to the access node (hybrid access node), another user, acting as a friendly interference node, uses the collected energy to scatter artificial noise throughout the electromagnetic environment to mask the transmission of confidential information, interfering with the eavesdropper's eavesdropping process. It is assumed that the friendly interference node uses a pseudo-random sequence to transmit artificial noise, which is known to the legitimate node but unknown to the eavesdropper. Therefore, the interference of the artificial noise is eliminated at the access node (hybrid access node), only confusing the eavesdropper. This pseudo-random sequence does not need to be pre-shared as in traditional cryptography; it can be achieved through channel estimation to assist in physical layer key generation and negotiation.

[0044] Let h ps h sa , These respectively represent: Energy Base Station - Transparent-Reflective Integrated Smart Metasurface, Transparent-Reflective Integrated Smart Metasurface - Access Node (or Hybrid Access Node), and Transparent-Reflective Integrated Smart Metasurface - U. r Transparent and reflective integrated intelligent metasurface - U t The signal vector between the integrated transflective and reflective intelligent metasurface-E1 and the integrated transflective and reflective intelligent metasurface-E2. Let... Representing energy base station-U r U r-Access point (or hybrid access node), U r -E1,U t -E2 channel coefficients. All channels are reciprocal and subject to quasi-static block fading, where the channel vector (or coefficients) remains constant within a time frame. Assume h ps h sa , and as well as Each component is an independent component with zero mean and unit variance.

[0045] Complex Gaussian distribution. Let G... a G p , These respectively represent the access node (or hybrid access node), the energy base station, and U. r U t Antenna gains for E1 and E2. β xy β represents the path loss from node x to node y. xsy d represents the path loss from node x to node y via the nth transparent-reflective integrated smart metasurface unit. xy This represents the distance between node x and node y.

[0046] Scenario I

[0047] When the direct power supply link is blocked, but there is a direct link between the access node and the outdoor user, the IbTOJI communication strategy and the IbJOTI communication strategy are set up in combination with the cooperative interference secure transmission method.

[0048] The IbTOJI communication strategy works as follows: During the energy harvesting phase, outdoor users collect radio frequency energy emitted by the energy base station based on the integrated transflective smart metasurface, providing energy for the information transmission phase. During the information transmission phase, outdoor users send confidential information to the access node, while artificial noise emitted by indoor users travels from indoors to outdoor space via the integrated transflective smart metasurface to interfere with the eavesdropping of the first eavesdropper. The IbJOTI communication strategy works as follows: During the energy harvesting phase, indoor users collect radio frequency energy emitted by the energy base station based on the integrated transflective smart metasurface, providing energy for the information transmission phase. During the information transmission phase, indoor users send confidential information to the receiving node based on the integrated transflective smart metasurface. Artificial noise emitted by outdoor users, upon reaching the integrated transflective smart metasurface, is partially reflected to interfere with the first eavesdropper, and partially transmitted into the indoor space to interfere with the second eavesdropper.

[0049] The energy collected in the IbTOJI policy and the energy collected in the IbJOTI policy are represented as follows.

[0050]

[0051]

[0052] Where κ represents energy conversion efficiency, η t and η r To facilitate the practical application and design of integrated transmissive and reflective intelligent metasurfaces, this invention ensures that each unit of the integrated transmissive and reflective intelligent metasurface has the same amplitude values ​​for both the transmission coefficient and the reflection coefficient, i.e., η. t =η t,n η r =η r,n , n∈[1,N], P s This indicates the transmission power of the power base station. Let φ represent the N×N diagonal reflection matrix of the integrated transmissive and reflective smart metasurface in scenario I, where φ r1,n This represents the reflection phase shift value of the nth unit in scene I. Let φ represent the N×N diagonal transmission matrix in scene I, where φ t1,n This represents the transmission phase shift value of the nth unit in scenario I, and each unit of the transmissive-reflective integrated smart metasurface is in a simultaneous transmission and reflection mode, with all units used to simultaneously reflect and transmit energy. Furthermore, These represent the energy base station's connection to Ur and U via the nth transparent-reflective integrated intelligent metasurface unit. t The path loss is represented by uppercase S, which indicates the area of ​​each unit, τ is the path loss exponent, and θ is the time allocation coefficient.

[0053] Then, U r U t The energy collected during the energy harvesting phase is used to transmit signals during the information transmission phase using a time interval of (1-θ)T. As shown in equations (1) and (2), and They represent U r and U t The transmission power.

[0054] IbTOJI Strategy: Access Nodes and U r There is a direct link between them without any obstructions. r When information is sent directly to the access node, the signal received by the access node can be represented as follows:

[0055]

[0056] in n0 represents the additive white Gaussian noise at the access node, and lowercase s is the incident signal. Correspondingly, the access node receives U... rThe signal-to-noise ratio of a signal can be expressed as:

[0057]

[0058] in, σ 2 It is the variance of additive white Gaussian noise.

[0059] During the information transmission phase of the IbTOJI strategy, U r Send confidential information, at this time U t The transmitted artificial noise travels from indoors to outdoor space via N adjustable units of the transmissive-reflective integrated smart metasurface. Because the eavesdropper's channel state information is unknown, the transmission phase shift of the transmissive-reflective integrated smart metasurface is adjusted to a random phase shift to interfere with E1's eavesdropping. E1 intercepts U... r There are three ways to eavesdrop on transmitted confidential information: through the reflective link of the integrated transflective-reflective intelligent metasurface; through direct eavesdropping via a direct link; and through both the direct link and the reflective link of the integrated transflective-reflective intelligent metasurface. E1 eavesdropped on U... r The signals can be represented as follows:

[0060]

[0061] Where j represents the interference signal. n e This represents additive white Gaussian noise at the eavesdropper's location. E1 intercepts U under three eavesdropping scenarios. r The signal-to-noise ratio of a signal can be expressed as follows.

[0062]

[0063] in

[0064] IbJOTI strategy: When U t When transmitting information to outdoor spaces, U is required. r Simultaneously interfere with the eavesdropping of E1 and E2. When U r When the emitted artificial noise reaches the integrated transparent and reflective smart metasurface, part of the artificial noise is reflected and propagates omnidirectionally, interfering with the hidden E1, while another part of the artificial noise is transmitted into the indoor space, interfering with the hidden E2. However, in the indoor space, not only does the artificial noise need to enter from the outside, but during this information transmission phase, U... t Information also needs to be transmitted from within. This requires the units of the integrated transmissive and reflective intelligent metasurface to achieve opposite transmission and propagation of two spatial signals. Therefore, we select N1 units of the integrated transmissive and reflective intelligent metasurface to transmit information, and the remaining N2 units to transmit artificial noise. The U received by the access node t The signal can be represented as:

[0065]

[0066] in Let N1×N1 represent the diagonal transmission matrix of the integrated transmissive and reflective smart metasurface in scenario I, where... This represents the transmission phase shift value of the n1th unit.

[0067] Accordingly, the access node receives U t The signal-to-noise ratio of a signal can be expressed as:

[0068]

[0069] Unlike the IbTOJI strategy, in the IbJOTI strategy, U r There are three ways to interfere with E1: interference via the reflection link of the integrated transflective-reflective smart metasurface; direct interference via the direct link; and simultaneous interference via both the direct link and the reflection link of the integrated transflective-reflective smart metasurface. Under these three interference scenarios, the U signal eavesdropped by E1... t The signals can be represented as follows:

[0070]

[0071] E1 steals U under 3 interference conditions t The signal-to-noise ratio of a signal can be expressed as follows.

[0072]

[0073] E2 and U t Both are indoor environments, U t The signal is transmitted through the integrated transmissive and reflective intelligent metasurface. The integrated transmissive and reflective intelligent metasurface does not correspond to U... t The emitted signal is reflected, and E2 can only pass through with U. t The direct link steals its information. When U r The emitted artificial noise is transmitted into the indoor space through N2 units of the transmissive-reflective integrated intelligent metasurface, achieving omnidirectional propagation and interfering with the concealed E2. E2 eavesdrops on U... t The signal is represented as:

[0074]

[0075] in This represents the N2×N2 diagonal transmission matrix of the integrated transmissive and reflective intelligent metasurface, where N1+N2=N. Let n2 represent the transmission phase shift value of the n2th unit in scene I, where n2∈[1,N2].

[0076] E2 steals U t The signal-to-noise ratio of a signal can be expressed as follows:

[0077]

[0078] Scene II

[0079] When the direct link for information transmission is blocked, the direct link between outdoor users and access nodes is obstructed by obstacles. In combination with the cooperative interference secure transmission method, IIbTOJI communication strategy and IIbJOTI communication strategy are set.

[0080] The IIbTOJI communication strategy is as follows: During the energy harvesting phase, outdoor users obtain radio frequency energy through a direct link with the energy base station to provide energy for the information transmission phase. During the information transmission phase, outdoor users send confidential information to the access node based on the integrated transflective smart metasurface. Artificial noise emitted by indoor users travels from the indoor space to the outdoor space via the integrated transflective smart metasurface to interfere with the eavesdropping of the first eavesdropper. The IIbJOTI communication strategy is as follows: During the energy harvesting phase, indoor users obtain radio frequency energy from the energy base station based on the integrated transflective smart metasurface to provide energy for the information transmission phase. During the information transmission phase, indoor users send confidential information to the receiving node via the integrated transflective smart metasurface. Artificial noise emitted by outdoor users, after reaching the integrated transflective smart metasurface, is partially reflected to interfere with the first eavesdropper, and partially transmitted into the indoor space to interfere with the second eavesdropper.

[0081] Specifically, in the IIbTOJI strategy, U r The energy collected, and U in the IIbJOTI strategy t The collected energy is represented as follows.

[0082]

[0083] in, This represents the N×N diagonal transmission matrix of the integrated transmissive and reflective intelligent metasurface in Scene II, where φ t2,n This represents the transmission phase shift of the nth unit in Scene II. and They represent U r and U t The transmission power. Other parameters of (21) and (22) are the same as those of (1) and (2).

[0084] IIbTOJI strategy. Access node and U r There are obstacles obstructing the view, U r The signal is transmitted to the access node via a transparent and reflective integrated smart metasurface. The signal received by the access node can be represented as:

[0085]

[0086] in, This represents the N×N diagonal reflection matrix of the integrated transmissive and reflective intelligent metasurface in Scene II, φ r2,n n∈N represents the reflection phase shift of the nth unit in Scene II. The unit of the integrated transmissive and reflective smart metasurface is in simultaneous transmission and reflection mode. Accordingly, the access node receives U r The signal-to-noise ratio of a signal can be expressed as:

[0087]

[0088] In the three eavesdropping scenarios, E1 eavesdrops on U in the IIbTOJI strategy. r The signals are represented as follows:

[0089]

[0090] Therefore, in three eavesdropping scenarios, E1 eavesdrops on U r The signal-to-noise ratio of a signal can be expressed as follows:

[0091]

[0092] IIbJOTI strategy. In this strategy, the access node receives U... t The signal can be represented as:

[0093]

[0094] in, Let N1×N1 be the diagonal transmission matrix in scene II, where, This represents the transmission phase shift of the n1-th cell. Correspondingly, the access node receives U... t The signal-to-noise ratio of a signal can be expressed as:

[0095]

[0096] In three eavesdropping scenarios, the U eavesdropped by E1 t The signals can be represented as follows:

[0097]

[0098] E1 steals U in 3 eavesdropping scenarios t The signal-to-noise ratio of a signal can be expressed as follows.

[0099]

[0100]

[0101] E2 eavesdropping on U t The signal can be represented as:

[0102]

[0103] in, E2 eavesdropping on U t The signal can be represented as:

[0104]

[0105] Scene III

[0106] The energy base station and access node are co-located as a hybrid access node; when both the direct power supply link and the direct information transmission link are blocked, the IIIbTOJI communication strategy and the IIIbJOTI communication strategy are set up in combination with the cooperative interference secure transmission method.

[0107] The IIIbTOJI communication strategy is as follows: During the energy harvesting phase, outdoor users obtain radio frequency energy from the hybrid access node based on the transparent-reflective integrated smart metasurface to provide energy for the information transmission phase; during the information transmission phase, outdoor users send confidential information to the hybrid access node, and artificial noise emitted by indoor users reaches the outdoor space from indoors through the transparent-reflective integrated smart metasurface to interfere with the eavesdropping of the first eavesdropper.

[0108] The IIIbJOTI communication strategy is as follows: During the energy harvesting phase, indoor users obtain radio frequency energy from the hybrid access node based on the integrated transparent and reflective smart metasurface to provide energy for the information transmission phase; during the information transmission phase, indoor users send confidential information to the hybrid access node through the integrated transparent and reflective smart metasurface. When artificial noise emitted by outdoor users reaches the integrated transparent and reflective smart metasurface, part of it is reflected to interfere with the first eavesdropper, and the other part is transmitted into the indoor space to interfere with the second eavesdropper.

[0109] Due to obstruction, U r and U t Energy harvesting and signal transmission both rely on the assistance of a transparent-reflective integrated smart metasurface. In the IIIbTOJI strategy, U... r The energy collected, and in the IIIbJOTI strategy U t The collected energy is represented as follows.

[0110]

[0111] in, Let φ represent the N×N diagonal reflection matrix and transmission matrix of the integrated transmissive and reflective intelligent metasurface in Scene III, respectively. r3,n ,φ t3,n ,n∈[1,N] represent the reflection phase shift and transmission phase shift of the nth unit, respectively. and They represent U r and U t The transmission power. The other parameters of (41) and (42) are the same as those of (1) and (2).

[0112] IIIbTOJI strategy. The signal received by the hybrid access node can be represented as:

[0113]

[0114] The unit cells of the integrated transmissive and reflective smart metasurface are simultaneously in transmission and reflection modes. Correspondingly, the hybrid access node receives U... r The signal-to-noise ratio of a signal can be expressed as:

[0115]

[0116] In the three eavesdropping scenarios, E1 eavesdrops on U in the IIIbTOJI strategy. r The signals are represented as follows:

[0117]

[0118] Therefore, in three eavesdropping scenarios, E1 eavesdrops on U r The signal-to-noise ratio of a signal can be expressed as follows:

[0119]

[0120] IIIbJOTI strategy. In this strategy, the access node receives U... t The signal can be represented as:

[0121]

[0122] in, This represents the N1×N1 diagonal transmission matrix of the integrated transmissive and reflective intelligent metasurface in Scene III, where... Let represent the transmission phase shift value of the n1-th unit in scenario III, where n1 ∈ [1, N1]. Correspondingly, the hybrid access node receives U... t The signal-to-noise ratio of a signal can be expressed as:

[0123]

[0124] Under three interference conditions, E1 eavesdropped on U t The signals can be represented as follows:

[0125]

[0126] E1 steals U in 3 eavesdropping scenarios t The signal-to-noise ratio of a signal can be expressed as follows.

[0127]

[0128] E2 eavesdropping on U t The signal can be represented as:

[0129]

[0130] in, In Scene III, the integrated transmissive and reflective intelligent metasurface features an N2×N2 diagonal transmission matrix. This represents the transmission phase shift value of the n2th unit in Scene III, where n2∈[1,N2], and E2 steals U. t The signal-to-noise ratio of a signal can be expressed as follows.

[0131]

[0132] Based on the signal-to-noise ratio of the received signals of each node obtained above, the present invention can calculate the connection interruption probability, confidentiality interruption probability, and effective confidentiality throughput of each strategy.

[0133] Connection interruption probability analysis

[0134] Communication connection interruption occurs when the main channel capacity drops below the predetermined codeword rate of the transmitted signal. The mathematical expression for the connection interruption probability is:

[0135]

[0136] Where ν∈{I,II,III} represents scenarios I, II, and III respectively, a represents the access node (hybrid access node), and u∈{r,t} refers to U. r and U t R t This represents the codeword rate of the expected transmitted signal. According to the definition in (61), the connection interruption probabilities of the six proposed schemes will be given next, where Pr[] represents the formula for calculating the probability of occurrence.

[0137] 1) IbTOJI strategy. IbTOJI strategy U r The probability of connection interruption during communication can be expressed as:

[0138]

[0139] in K is a parameter for accuracy and complexity. 2) IbJOTI strategy. IbJOTI strategy U t The probability of connection interruption during communication can be expressed as:

[0140]

[0141] Where γ(·,·) is the lower incomplete Gamma function.

[0142] 3) IIbTOJI strategy. IIbTOJI strategy U r The probability of connection interruption during communication can be expressed as:

[0143]

[0144]

[0145] 4) IIbJOTI. IIbJOTI strategy U t The probability of connection interruption during communication can be expressed as:

[0146]

[0147] 5) IIIbTOJI strategy. IIIbTOJI strategy U r The probability of connection interruption during communication can be expressed as:

[0148]

[0149] 6) IIIbJOTI strategy. IIIbJOTI strategy U t The probability of connection interruption during communication can be expressed as:

[0150]

[0151] Security Interruption Probability Analysis

[0152] According to the well-known Wynerian eavesdropping theory, a security breach will occur when the eavesdropping channel capacity exceeds the redundancy (cost) rate of the eavesdropping code. Its mathematical expression is:

[0153]

[0154] Where R s R represents the predetermined security rate of the expected signal. t -R s Let e ​​∈ {e1, e2} represent E1 and E2 respectively, and ∈ = {1, 2, 3}. According to the definition in (74), the probability of security breach for the six proposed schemes will be given next.

[0155] 1) IbTOJI strategy. The closed-form expression for the probability of security breach in IbTOJI can be obtained as follows.

[0156] In three eavesdropping scenarios It can be uniformly represented as:

[0157]

[0158] Where i represents an imaginary number, and Γ(·,·) represents the upper incomplete Gamma function.

[0159]

[0160] 2) IbJOTI strategy. The probability of security breach in the IbJOTI scheme during E1 and E2 eavesdropping was analyzed as follows.

[0161] a) E1 eavesdropping. When dealing with E1 eavesdropping, the closed-form expression for the probability of security interruption in IbTOJI can be obtained as follows.

[0162] Under three interference conditions It can be uniformly represented as:

[0163]

[0164] in

[0165] b) E2 eavesdropping. When dealing with E2 eavesdropping, the closed-form expression for the probability of security breach in IbTOJI can be obtained as follows.

[0166] In countering E2 eavesdropping It can be represented as:

[0167]

[0168] in

[0169] 3) IIbTOJI strategy. The closed-form expression for the secrecy interruption probability in IIbTOJI can be obtained as follows.

[0170] In three eavesdropping scenarios It can be uniformly represented as:

[0171]

[0172] in

[0173] 4) IIbJOTI strategy. The probability of security breach in the IIbJOTI scheme during E1 and E2 eavesdropping was analyzed as follows.

[0174] a) E1 eavesdropping. Substituting (36), (37), and (38) into (74), the closed-form expression for the probability of security interruption in IIbTOJI when dealing with E1 eavesdropping can be obtained as follows.

[0175] Under three interference conditions It can be uniformly represented as:

[0176]

[0177] in Ei(·) Exponential integral function

[0178] b) E2 eavesdropping. Substituting (40) into (74), the closed-form expression for the probability of security interruption in IbTOJI when dealing with E2 eavesdropping can be obtained as follows.

[0179] In countering E2 eavesdropping It can be represented as:

[0180]

[0181] in

[0182] 5) IIIbTOJI strategy. Substituting (48), (49), and (50) into (74), the closed-form expression for the secrecy interruption probability in IIIbTOJI can be obtained as follows.

[0183] In three eavesdropping scenarios It can be uniformly represented as:

[0184]

[0185] in,

[0186] prove: They respectively obey the parameters as An exponential random variable.

[0187] 6) IIIbJOTI Strategy. The probability of security breach in the IIIbJOTI scheme during E1 and E2 eavesdropping was analyzed as follows.

[0188] a) E1 eavesdropping. When dealing with E1 eavesdropping, the closed-form expression for the probability of security breach in IIIbTOJI can be obtained as follows. Under the three interference conditions, It can be uniformly represented as:

[0189]

[0190] in

[0191] b) E2 eavesdropping. When dealing with E2 eavesdropping, the closed-form expression for the probability of security interruption in IIIbTOJI can be obtained as follows.

[0192] In countering E2 eavesdropping It can be represented as:

[0193]

[0194] in

[0195] Effective confidential throughput analysis

[0196] According to the definition:

[0197]

[0198] When facing multiple eavesdroppers, the effective confidentiality throughput of the system should be analyzed under the condition with the worst confidentiality performance. According to theoretical derivation and simulation calculation, the effect of resisting E2 eavesdropping is poor when communicating with indoor users. Therefore, the effective confidentiality throughput of the proposed secure transmission strategy for indoor user communication should be analyzed under the condition of E2 eavesdropping. According to the definition in (84), the effective confidentiality throughput of the six proposed schemes will be given below.

[0199] 1) IbTOJI strategy. The closed-form expression for the effective confidential throughput in IbTOJI can be obtained as follows.

[0200] In three eavesdropping scenarios It can be represented as:

[0201]

[0202] 2) IbJOTI strategy. The closed-form expression for the effective secure throughput under E2 eavesdropping conditions in the IbJOTI strategy can be obtained as follows.

[0203] It can be represented as:

[0204]

[0205]

[0206] 3) IIbTOJI strategy. The closed-form expression for the effective confidential throughput in IIbTOJI can be obtained as follows.

[0207] In three eavesdropping scenarios It can be represented as:

[0208]

[0209] 4) IIbJOTI strategy. The closed-form expression for the effective secure throughput under E2 eavesdropping conditions in the IIbJOTI strategy can be obtained as follows.

[0210] It can be represented as:

[0211]

[0212] 5) IIIbTOJI Strategy. The closed-form expression for effective secure throughput in IIIbTOJI can be obtained as follows. Under the three eavesdropping scenarios, It can be represented as:

[0213]

[0214] 6) IIIbJOTI strategy. The closed-form expression for the effective secure throughput under E2 eavesdropping conditions in the IIIbJOTI strategy can be obtained as follows. It can be represented as:

[0215]

[0216] Based on the above embodiments, as an optional embodiment, the cooperative interference secure transmission method based on a transflective integrated smart metasurface provided by the present invention further includes: changing the number of reflective elements of the transflective integrated smart metasurface, calculating key parameters of communication performance under different secure communication strategies, so as to analyze the impact of the number of reflective elements on different secure communication strategies; and changing the transmission power of the energy base station, calculating key parameters of communication performance under different secure communication strategies, so as to analyze the impact of the transmission power of the energy base station on different secure communication strategies.

[0217] Figure 3 This is a schematic diagram illustrating the communication interruption probability of various strategies under different power levels, provided in an embodiment of the present invention. Figure 3 As shown, although the integrated transparent and reflective smart metasurface enhances U t The energy harvesting and information transmission process, but at low to medium RF power (below 32dBm), the connection interruption probability of the IbJOTI, IIbJOTI, and IIIbJOTI strategies was not as good as expected compared to the IbTOJI and IIbTOJI strategies. At RF power exceeding 27dBm, U t The reliability performance rapidly improved and surpassed the IbTOJI and IIbTOJI strategies by 32dBm. This result is due to the integrated transparent / reflective smart metasurface's ability to handle U... t The information transmission gain is "discounted," requiring more energy to excite the transparent-reflective integrated smart metasurface to U when the number of units used for information transmission is reduced. tThe gain effect of communication, which is why when the RF power is high, U t The reliability of communication will be significantly better than the IbTOJI and IIbTOJI strategies.

[0218] Figure 4 This is a schematic diagram illustrating the probability of user communication interruption under different strategies and different numbers of unit reflective elements provided in an embodiment of the present invention, such as... Figure 4 As shown, the gain for the IIIbTOJI strategy is most significant when N increases, followed by the IbJOTI, IIbJOTI, and IIIbJOTI strategies. Meanwhile, the gain effect on the IbTOJI and IIbTOJI strategies gradually weakens as N increases.

[0219] Figure 5 This is a schematic diagram illustrating the probability of user security interruption under different strategies and power levels, provided by an embodiment of the present invention. Figure 5 As shown, the probability of confidentiality interruption for the six proposed secure transmission strategies is compared and analyzed. Figure 5 The results show that the IbJOTI and IIIbJOTI strategies offer the best security performance against E1 eavesdropping among all strategies. This is because the friendly interference node U in the IbJOTI and IIIbJOTI strategies... r Energy is harvested through N units of the transflective-reflective integrated smart metasurface. Compared to the IIbTOJI strategy, which directly obtains energy from the base station, more energy is obtained for transmitting jamming signals. The stronger the jamming signal, the better the interference effect on eavesdropping, and the better the system security. At low power, the IIbTOJI strategy is more secure than the IbTOJI and IIIbTOJI strategies. There are two reasons for this: 1. In the IIbTOJI strategy, U... r 1. Directly obtaining energy from the base station results in poor signal quality for E1 under the same interference conditions; 2. The information transmission of the IIbTOJI strategy utilizes the optimal phase shift design of the transparent-reflective integrated intelligent metasurface, resulting in less information leakage.

[0220] Figure 6 This is a schematic diagram illustrating the probability of user privacy interruption under different strategies and with different numbers of units, provided in an embodiment of the present invention. Figure 6 As shown, the IbTOJI strategy transmits information and noise through N units; the IbJOTI strategy, when dealing with E1 eavesdropping, transmits information through N1 units and noise through N units; the IbJOTI strategy, when dealing with E2 eavesdropping, is directly eavesdropped upon, and only transmits noise through N2 units. Changes in the number of units used for transmitting information and noise will affect the system's security performance.

[0221] Figure 7This is a schematic diagram illustrating the effective confidential throughput of users under different strategies and at different power levels, provided by embodiments of the present invention. It can be seen that the derivation of the theoretical values ​​matches the simulation results. Overall, the IbTOJI strategy exhibits good comprehensive performance. Although the reliability and security of the IbTOJI strategy are not the best among all strategies, its reliability and security metrics consistently remain at a mid-to-high level across all power values, without experiencing a sharp deterioration in reliability and security at any particular power value. Therefore, its overall performance is the most outstanding. In the low-power region, the IbTOJI and IIIbTOJI strategies show good overall performance. In the high-power region, the IIbTOJI (E2) strategy performs well because the impact of security and reliability on overall performance varies across different power ranges. Figure 3 As shown, the IbTOJI and IIIbTOJI strategies exhibit the same reliability performance at low transmission power, and are superior to the IbJOTI and IIIbJOTI strategies. Therefore, at low transmission power, system reliability has a greater impact on overall performance than security. In the high-power region, the reliability of each strategy is enhanced due to the increased transmission power. In this region, system security becomes a crucial factor affecting overall performance. Furthermore, in the high-power region, the reliability of the IbJOTI and IIIbJOTI strategies far surpasses that of the IbTOJI and IIIbTOJI strategies, resulting in better overall performance.

[0222] Figure 8 This is a schematic diagram illustrating the effective confidentiality throughput of outdoor users with different numbers of units under different strategies, provided in an embodiment of the present invention. Figure 9 This is a schematic diagram illustrating the effective secure throughput of indoor users with different numbers of units under different strategies, provided by an embodiment of the present invention. It can be seen that when a suitable power value is selected, the effective secure throughput value of each strategy increases with the increase of N. This is because when cooperative interference nodes are introduced into the wireless power supply and communication system assisted by the integrated transmissive and reflective intelligent metasurface, within a suitable power range, the system's secure interruption probability will not deteriorate to 1 with the increase of N, but rather tends to a constant value less than 1. This results in a decrease in the system connection interruption probability when N increases. Considering all these factors, the effective secure throughput under each strategy gradually increases and tends to stabilize. It is not difficult to see that... Figure 8 IIIbTOJI strategy and Figure 9 When the IbJOTI strategy E2 eavesdropping and the IIIbJOTI strategy E2 eavesdropping are used, the overall performance gain is significant as the number of units increases. This is because the above strategies are closely related to the user's energy acquisition and information reception stages with the transparent and reflective integrated smart metasurface, so the performance improvement is more significant.

[0223] On the other hand, the present invention also provides a cooperative interference secure transmission system based on a transparent-reflective integrated intelligent metasurface, including an access node, an energy base station, two legitimate users, and two eavesdroppers, characterized in that a secure communication strategy is set by applying any of the aforementioned cooperative interference secure transmission methods based on a transparent-reflective integrated intelligent metasurface.

[0224] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for secure transmission through cooperative interference based on a transflective-reflective integrated intelligent metasurface, characterized in that, include: Build secure communication scenarios; The secure communication scenario includes an access node, an energy base station, two legitimate users, and two eavesdroppers. The two legitimate users are an outdoor user and an indoor user, and the two eavesdroppers are a first eavesdropper corresponding to the outdoor user and a second eavesdropper corresponding to the indoor user. In the secure communication scenario, a smart metasurface integrating transmission and reflection is deployed, which has the function of remodulating the incident signal into a transmitted signal or a reflected signal, to divide the communication space into a transmission space and a reflection space; outdoor users, energy base stations, access nodes and the first eavesdropper are deployed in the reflection space, and indoor users and the second eavesdropper are deployed in the transmission space. Different secure communication strategies are set up by combining cooperative interference secure transmission methods in different communication link scenarios; The method of coordinated interference secure transmission involves indoor and outdoor users sending artificial noise to interfere with eavesdroppers' eavesdropping while one party is communicating. The key parameters of communication performance for each secure communication strategy are calculated and analyzed to select the required secure communication strategy based on actual needs. The key parameters of the communication performance include the interruption probability, the confidentiality interruption probability, and the effective confidentiality throughput. Among them, different secure communication strategies are set up by combining the cooperative interference secure transmission method under different communication link scenarios, including: The energy base station and access node are co-located as a hybrid access node; When both the power supply direct link and the information transmission direct link are blocked, the IIIbTOJI communication strategy and the IIIbJOTI communication strategy are set up in combination with the cooperative interference secure transmission method. The IIIbTOJI communication strategy is as follows: During the energy harvesting phase, the outdoor user obtains radio frequency energy from the hybrid access node based on the transparent and reflective integrated smart metasurface to provide energy for the information transmission phase; during the information transmission phase, the outdoor user sends confidential information to the hybrid access node, and the artificial noise emitted by the indoor user reaches the outdoor space from the indoor space through the transparent and reflective integrated smart metasurface to interfere with the eavesdropping of the first eavesdropper. The IIIbJOTI communication strategy is as follows: During the energy harvesting phase, indoor users obtain radio frequency energy from the hybrid access node based on the integrated transparent and reflective smart metasurface to provide energy for the information transmission phase; during the information transmission phase, indoor users send confidential information to the hybrid access node via the integrated transparent and reflective smart metasurface. When artificial noise emitted by outdoor users reaches the integrated transparent and reflective smart metasurface, part of it is reflected to interfere with the first eavesdropper, and the other part is transmitted into the indoor space to interfere with the second eavesdropper.

2. The method for cooperative interference secure transmission based on a transflective integrated intelligent metasurface according to claim 1, characterized in that, Indoor and outdoor users may send artificial noise to interfere with eavesdropping while one party is communicating, including: When outdoor users are communicating, indoor users emit artificial noise to interfere with the first eavesdropper based on a transparent and reflective integrated intelligent metasurface. When indoor users are communicating, outdoor users can interfere with the first and second eavesdroppers based on the transparent and reflective integrated smart metasurface.

3. The cooperative interference secure transmission method based on a transflective integrated intelligent metasurface according to claim 1, characterized in that, In different communication link scenarios, different secure communication strategies are set by combining cooperative interference secure transmission methods, including: When the direct power supply link is blocked, but there is a direct link between the access node and the outdoor user, the IbTOJI communication strategy and the IbJOTI communication strategy are set up in combination with the cooperative interference secure transmission method. The IbTOJI communication strategy is as follows: During the energy harvesting phase, the outdoor user collects the radio frequency energy emitted by the energy base station based on the transparent and reflective integrated intelligent metasurface to provide energy for the information transmission phase; During the information transmission phase, the outdoor user sends confidential information to the access node, and the artificial noise emitted by the indoor user reaches the outdoor space from the indoor space through the transparent and reflective integrated intelligent metasurface to interfere with the eavesdropping of the first eavesdropper. The IbJOTI communication strategy is as follows: During the energy harvesting phase, indoor users collect radio frequency energy emitted by the energy base station based on the integrated transparent and reflective smart metasurface to provide energy for the information transmission phase; during the information transmission phase, indoor users send confidential information to the receiving node based on the integrated transparent and reflective smart metasurface; after the artificial noise emitted by outdoor users reaches the integrated transparent and reflective smart metasurface, part of it is reflected to interfere with the first eavesdropper, and the other part is transmitted into the indoor space to interfere with the second eavesdropper.

4. The cooperative interference secure transmission method based on a transflective integrated intelligent metasurface according to claim 1, characterized in that, In different communication link scenarios, different secure communication strategies are set by combining cooperative interference secure transmission methods, including: When the direct link for information transmission is blocked, the direct link between outdoor users and access nodes is obstructed by obstacles. In combination with the cooperative interference secure transmission method, IIbTOJI communication strategy and IIbJOTI communication strategy are set. The IIbTOJI communication strategy is as follows: During the energy harvesting phase, outdoor users obtain radio frequency energy through a direct link with the energy base station to provide energy for the information transmission phase; During the information transmission phase, outdoor users send confidential information to the access node based on the transparent and reflective integrated smart metasurface, and artificial noise emitted by indoor users travels from the indoor space to the outdoor space through the transparent and reflective integrated smart metasurface to interfere with the eavesdropping of the first eavesdropper. The IIbJOTI communication strategy is as follows: During the energy harvesting phase, indoor users obtain radio frequency energy from the energy base station based on the integrated transflective smart metasurface to provide energy for the information transmission phase; during the information transmission phase, indoor users send confidential information to the receiving node through the integrated transflective smart metasurface; after the artificial noise emitted by the outdoor user reaches the integrated transflective smart metasurface, part of it is reflected to interfere with the first eavesdropper, and the other part is transmitted into the indoor space to interfere with the second eavesdropper.

5. The method for cooperative interference secure transmission based on a transflective integrated intelligent metasurface according to claim 1, characterized in that, Also includes: By varying the number of reflective elements in the transflective-reflective integrated smart metasurface, key parameters of communication performance under different secure communication strategies were calculated to analyze the impact of the number of reflective elements on different secure communication strategies.

6. The method for cooperative interference secure transmission based on a transflective integrated intelligent metasurface according to claim 1, characterized in that, Also includes: By changing the transmission power of the energy base station, the key parameters of communication performance under different secure communication strategies are calculated to analyze the impact of the energy base station's transmission power on different secure communication strategies.

7. A cooperative interference secure transmission system based on a transparent-reflective integrated intelligent metasurface, comprising an access node, an energy base station, two legitimate users, and two eavesdroppers, characterized in that, A secure communication strategy is set up using the cooperative interference secure transmission method based on a transparent-reflective integrated intelligent metasurface as described in any one of claims 1 to 6.

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