Multi-user integrated sensing and communication method based on superfluid antenna and related device

Abstract

The invention provides a multi-user integrated perception and communication method based on a superfluid antenna and a related device. The method is applied to a multi-user integrated perception and communication system based on the superfluid antenna. In the invention, by means of an integrated system design, on shared hardware and spectrum resources, multiple groups of measurement data are acquired based on space diversity provided by MFA, and the spatial position and shape of a target scatterer in a region of interest are reconstructed through a transmitter and a receiver based on MFA by adopting an inverse scattering algorithm; based on the dynamic activation mode of the MFA, the optimal antenna activation mode meeting the signal-to-interference ratio threshold is dynamically searched for each user, reliable communication between a transmitter and a plurality of users equipped with the MFA is guaranteed, and therefore the high-performance environment perception and the high-reliability multi-user communication function are synchronously achieved.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a multi-user integrated sensing and communication method and related apparatus based on a superfluid antenna. Background Technology

[0002] To achieve the goals of ultra-high data rates, highly reliable connections, and seamless coverage in 6G mobile networks, Integrated Sensing and Communication (ISAC) technology has become a key development direction. ISAC achieves joint utilization of communication and sensing functions by sharing hardware and spectrum, thereby improving spectrum efficiency, reducing equipment redundancy, and lowering latency. Multiple-Input Multiple-Output (MIMO), as the foundational technology of ISAC, typically relies on fixed-position antennas (FPAs). However, the fixed geometry of these antennas limits their dynamic adaptability to constantly changing sensing and communication requirements. Unlike traditional FPAs, fluid antenna (FA) systems can dynamically adjust the position of components using mechanical or electronic means, bringing new spatial flexibility at the physical layer. However, current FA-ISAC systems (based on liquid antennas or using mechanically movable antennas) are limited by hardware, affecting the system's sensing and communication performance, especially in multi-user scenarios where balancing sensing accuracy and communication performance is difficult. Summary of the Invention

[0003] This invention provides a multi-user integrated sensing and communication method and related apparatus based on a superfluid antenna, which solves the technical problem that the current FA-ISAC system is unable to balance sensing accuracy and communication performance in multi-user scenarios.

[0004] This invention provides a multi-user integrated sensing and communication method based on a superfluid antenna. The method is applied to a multi-user integrated sensing and communication system based on a superfluid antenna, the system comprising a region of interest, a transmitter equipped with an RFPA, a receiver equipped with an MFA, and multiple users equipped with MFAs; the MFA includes multiple reconfigurable radiating elements; the method includes:

[0005] A composite communication waveform carrying different user data is transmitted via the FPA of the transmitter; the composite communication waveform is used to illuminate the region of interest to form a scattered signal.

[0006] Adjust the sensing-activated antenna element subset of the receiver's MFA so that the receiver's MFA receives the scattered signal under different sensing-activated antenna element subsets; measure the received signal voltage of the receiver under different sensing-activated antenna element subsets;

[0007] The reflection coefficient is estimated based on multiple received signal voltages using an inverse scattering algorithm, and the scattering body in the region of interest is identified by the reflection coefficient to achieve sensing.

[0008] Calculate the FPA of the transmitter and the channel link vector of each user. Based on the preset signal-to-interference ratio threshold and the channel link vector, determine the optimal antenna activation mode of each user's MFA, thereby controlling the switching state of multiple reconfigurable radiating elements between radiating and non-radiating states, and obtaining the optimal subset of communication active antenna elements for each user.

[0009] Based on the optimal subset of communication active antenna elements for each user, the composite communication waveform is received through the MFA of each user, and the transmission symbol data of each user is obtained by decoding the composite communication waveform to realize communication.

[0010] Optionally, the step of estimating the reflection coefficient based on multiple received signal voltages using an inverse scattering algorithm, and identifying the scatterer in the region of interest using the reflection coefficient to achieve sensing, includes:

[0011] Based on the inverse scattering algorithm, the electromagnetic measurement vector of the receiver is calculated under different subsets of sensing active antenna elements, and a sensing model of the received signal voltage and electromagnetic measurement vector under different subsets of sensing active antenna elements is established.

[0012] The reflection coefficient is estimated based on the sensing model using compressed sensing and a two-step iterative shrinking threshold algorithm.

[0013] The scatterer in the region of interest is identified by the reflection coefficient to achieve perception.

[0014] Optionally, the step of calculating the FPA of the transmitter and the channel link vector of each user, determining the optimal antenna activation mode of each user's MFA based on a preset signal-to-interference ratio threshold and the channel link vector, thereby controlling the switching state of multiple reconfigurable radiating elements between radiating and non-radiating states, and obtaining the optimal subset of communication active antenna elements for each user, includes:

[0015] Calculate the FPA of the transmitter and the channel link vectors of each user;

[0016] Based on the SRMPA algorithm, multiple candidate antenna activation modes are generated by searching according to a preset antenna activation mode and a preset iteration threshold; the signal-to-interference ratio of different antenna activation modes is calculated iteratively based on the channel link vector and the multiple antenna activation modes.

[0017] If the calculated signal-to-interference ratio (SIR) is greater than or equal to a preset SIR threshold, then the antenna activation mode corresponding to the first SIR greater than the preset SIR threshold is taken as the optimal antenna activation mode; if the number of calculation iterations reaches the preset iteration threshold and the calculated SIR is less than the preset SIR threshold, then the antenna activation mode corresponding to the largest calculated SIR is taken as the optimal antenna activation mode.

[0018] Based on the optimal antenna activation mode of each user's MFA, multiple reconfigurable radiating elements are controlled to switch between radiating and non-radiating states, thereby obtaining the optimal subset of communication active antenna elements for each user.

[0019] Optionally, the MFA may further include a substrate-integrated waveguide structure and a PIN diode;

[0020] The reconfigurable radiating element is disposed on the upper layer of the substrate integrated waveguide structure and is electromagnetically coupled to the substrate integrated waveguide structure;

[0021] The PIN diode is embedded in the substrate integrated waveguide structure and is located at the circuit connection between the reconfigurable radiating element and the substrate integrated waveguide structure, and is used to control the reconfigurable radiating element to switch to a radiating state or a non-radiating state.

[0022] Each of the MFAs is connected to the radio frequency chain through the substrate integrated waveguide structure for transmitting signals from the radio frequency chain, so that the reconfigurable radiating element switched to the radiating state couples the signal transmitted by the substrate integrated waveguide structure into free space.

[0023] Optionally, the received signal voltage is expressed as:

[0024]

[0025] In the formula: The measured received signal voltage; To sense and activate a subset of antenna elements, j= The imaginary unit is ω, and the angular frequency is ω. Permeability in free space and All are normalized constants; For the first The electric field of an activated reconfigurable radiative element; The total electric field from the transmitter at the region of interest; This is the reflection coefficient vector;

[0026] The electromagnetic measurement vector is represented as follows:

[0027]

[0028] In the formula: This is the electromagnetic measurement vector;

[0029] The sensing model of the received signal voltage and the electromagnetic measurement vector is expressed as follows:

[0030]

[0031] In the formula: The reflection coefficient;

[0032] The sensing model of the received signal voltage versus the measurement vector under different subsets of sensing activated antenna elements is then expressed as:

[0033]

[0034] In the formula: The voltage vector formed by the received signal voltage under different subsets of sensing activated antenna elements; The measurement matrix is ​​formed by the measurement vectors under different subsets of sensing activated antenna elements.

[0035] Optionally, the signal-to-interference ratio is calculated as follows:

[0036]

[0037] In the formula: The signal-to-interference ratio for user u; Let be the radiation response vector of the MFA; Let FPA be the channel link vector between the transmitter and user u; For the set of all users;

[0038] in,

[0039]

[0040] In the formula: Antenna activation mode, N is the number of controllable radiation elements in the MFA. A value of 0 indicates that the Nth controllable radiating element is in a non-radiating state. A value of 1 indicates that the object is in a radiating state. The phase response vector is determined by the physical structure of the antenna with N controllable radiating elements; This is an element-wise multiplication operation.

[0041] The present invention also provides a multi-user integrated sensing and communication device based on a superfluid antenna, the device comprising:

[0042] The transmitting module is used to transmit a composite communication waveform carrying different user data through the FPA of the transmitter; and to irradiate the region of interest with the composite communication waveform to form a scattered signal.

[0043] A receiver receiving module is used to adjust the sensing active antenna element subset of the receiver's MFA so that the receiver's MFA receives the scattered signal under different sensing active antenna element subsets; and to measure the received signal voltage of the receiver under different sensing active antenna element subsets.

[0044] The sensing module is used to estimate the reflection coefficient based on multiple received signal voltages using an inverse scattering algorithm, and to identify the scattering body in the region of interest through the reflection coefficient to achieve sensing.

[0045] The user activation selection module is used to calculate the FPA of the transmitter and the channel link vector of each user. Based on the preset signal-to-interference ratio threshold and the channel link vector, it determines the optimal antenna activation mode of each user's MFA, thereby controlling the switching state of multiple reconfigurable radiating elements between radiating and non-radiating states, and obtaining the optimal subset of communication active antenna elements for each user.

[0046] The communication module is used to receive the composite communication waveform through the MFA of each user based on the optimal subset of communication activation antenna elements for each user, and to decode the composite communication waveform to obtain the transmission symbol data of each user in order to realize communication.

[0047] The present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the multi-user integrated sensing and communication method based on a superfluid antenna as described above.

[0048] The present invention also provides a computer-readable storage medium having a computer program or instructions stored thereon, wherein the computer program or instructions, when executed by a processor, implement the steps of the multi-user integrated sensing and communication method based on a superfluid antenna as described above.

[0049] The present invention also provides a computer program product, including a computer program or instructions, which, when executed by a processor, implement the steps of the multi-user integrated sensing and communication method based on a superfluid antenna as described above.

[0050] As can be seen from the above technical solutions, the present invention has the following advantages:

[0051] This invention provides a multi-user integrated sensing and communication method and related apparatus based on a superfluid antenna. The method is applied to a multi-user integrated sensing and communication system based on a superfluid antenna. The system includes a region of interest (ROI), a transmitter equipped with a field-activated antenna (FPA), a receiver equipped with a multi-user antenna array (MFA), and multiple users equipped with MFAs. The MFA includes multiple reconfigurable radiating elements. The method includes: transmitting a composite communication waveform carrying data from different users through the FPA of the transmitter; illuminating the ROI with the composite communication waveform to form a scattered signal; adjusting a subset of sensing active antenna elements of the receiver's MFA so that the receiver's MFA receives the scattered signal under different subsets of sensing active antenna elements; and measuring the data under different subsets of sensing active antenna elements. The invention utilizes an integrated system design to simultaneously achieve high-performance environmental sensing and highly reliable multi-user communication on shared hardware and spectrum resources. It calculates the channel link vectors between the transmitter's FPA and each user's MFA based on a preset signal-to-interference ratio (SIR) threshold and the channel link vectors. This determines the optimal antenna activation mode for each user's MFA, controlling the switching between radiating and non-radiating states of multiple reconfigurable radiating elements, thus obtaining the optimal subset of active communication antenna elements for each user. Based on this optimal subset, the invention receives composite communication waveforms through each user's MFA and decodes these waveforms to obtain the transmitted symbol data for each user, achieving communication. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of the present 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 only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 A flowchart illustrating the steps of a multi-user integrated sensing and communication method based on a superfluid antenna, as provided in this embodiment of the invention;

[0054] Figure 2 A schematic diagram of a multi-user integrated sensing and communication system based on a superfluid antenna provided in an embodiment of the present invention;

[0055] Figure 3 A schematic diagram of the configuration structure of MFA provided in an embodiment of the present invention;

[0056] Figure 4 (a) is the measurement matrix of a multi-user ISAC based on MFA provided in an embodiment of the present invention. The amplitude distribution diagram of the radiation field was simulated and analyzed. Figure 4 (b) is the measurement matrix of MFA-based multi-user ISAC provided in the embodiment of the present invention. The phase distribution diagram of the radiation field was simulated and analyzed. Figure 4 (c) is the measurement matrix of the MFA-based multi-user ISAC provided in the embodiment of the present invention. Simulation analysis of normalized SVD spectra; Figure 4 (d) is the measurement matrix of the MFA-based multi-user ISAC provided in the embodiment of the present invention. The perceived capacity curve from the simulation analysis;

[0057] Figure 5 (a) is a real-world sensing image based on a single matrix scatterer with a length of 10 mm and a width of 5 mm, provided in an embodiment of the present invention. Figure 5 (b) is a reconstruction analysis sensing image based on a single matrix scatterer with a length of 10 mm and a width of 5 mm provided in an embodiment of the present invention;

[0058] Figure 6 (a) is a real-world sensing image based on two identical matrix scatterers with a width of 5 mm provided in an embodiment of the present invention; Figure 6 (b) is a reconstruction analysis sensor image based on two identical matrix scatterers with a width of 5 mm provided in an embodiment of the present invention;

[0059] Figure 7 (a) is a comparative analysis of the interruption probability and SIR threshold of the SRMPA FAMA, Slow-FAMA and MRC-FAS schemes provided in the embodiments of the present invention when U=5. Figure 7 (b) is a comparison and analysis of the multiplexing gain and SIR threshold results of the SRMPAFAMA, Slow-FAMA and MRC-FAS schemes provided in the embodiments of the present invention when U=5.

[0060] Figure 8 (a) is a comparative analysis of the interruption probability and SIR threshold results of simulation experiments and theoretical calculations of multi-user ISAC technology based on MFA provided in the embodiments of the present invention; Figure 8 (b) is a comparison and analysis of the results of simulation experiments and theoretical calculations of multiplexing gain and SIR threshold of MFA-based multi-user ISAC technology provided in the embodiments of the present invention;

[0061] Figure 9 This is a structural block diagram of a multi-user integrated sensing and communication device based on a superfluid antenna, provided for an embodiment of the present invention. Detailed Implementation

[0062] This invention provides a multi-user integrated sensing and communication method and related apparatus based on a superfluid antenna, which solves the technical problem that the current FA-ISAC system is unable to balance sensing accuracy and communication performance in multi-user scenarios.

[0063] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0064] Please see Figure 1 This invention provides a multi-user integrated sensing and communication method based on a superfluid antenna, the method comprising:

[0065] Step 101: Transmit a composite communication waveform carrying different user data through the FPA of the transmitter; illuminate the region of interest with the composite communication waveform to form a scattered signal.

[0066] It should be noted that this invention applies to a multi-user integrated sensing and communication system based on a superfluid antenna, which integrates communication and sensing functions; please refer to [link to relevant documentation]. Figure 2 The system's base station (BS) is equipped with a transmitter featuring a fixed-position antenna (FPA) and a receiver featuring a meta-fluid antenna (MFA); each communication user (indexed by u) is also equipped with an MFA. The receiving side of the base station is equipped with a receiver (receiving antenna) featuring a 6×9 grid of MFAs. Figure 2 The green and red grids in the diagram represent the controlled radiating elements of the MFA in radiating and non-radiating states, respectively. This structural design allows for dynamic reconfiguration of the radiation pattern, helping to mitigate interference and improve signal quality. Utilizing the FA Multiple Access (FAMA) principle of fluid antennas, the MFA-based communication framework allows the base station to provide services to users (u) using a single radio-frequency (RF) chain, ensuring efficient multi-user communication within the ISAC framework. For the sensing target, a signal is transmitted via a transmitter (transmitting antenna), the signal illuminates the sensing target to form a scattered signal, which is then received by a receiver.

[0067] For details, please refer to Figure 3 (a) The MFA also includes a substrate-integrated waveguide (SIW) structure and PIN diodes. The reconfigurable radiating element is disposed on the upper layer of the substrate-integrated waveguide structure and is electromagnetically coupled to the substrate-integrated waveguide structure. The PIN diodes are embedded in the substrate-integrated waveguide structure and are located at the circuit connection between the reconfigurable radiating element and the substrate-integrated waveguide structure. The reconfigurable radiating element consists of two slot structures: a "+" slot and a "-" slot. These two slots are etched onto the metal layer of the substrate integrated waveguide (SIW) and function as magnetic dipoles. The reconfigurable radiating element is independently controlled to switch between radiating and non-radiating states by PIN diodes embedded within the SIW structure. Specifically, four PIN diodes control the selective activation of each reconfigurable radiating element. When an element is activated, it is in a radiating state with a power of 13.5 dB, while inactive elements remain in a non-radiating state with a power of approximately 0.5 dB. This power difference between states ensures robust signal control.

[0068] For example, such as Figure 3 As shown in (b), the MFA can be configured to have An array of reconfigurable radiating elements, arranged in lines and The column covers an area of ,in and These are the electrical dimensions of the array in two dimensions. The wavelength is given. Under different activation modes, the electric field distribution above the antenna (Distribution Code 1…Distribution Code p) exhibits dynamic, fluid-like characteristics. In practical applications, fine-grained, programmable control of the radiation mode can be achieved by selectively activating either the "+" or "-" shaped slots. The MFA connects a single RF chain via a substrate-integrated waveguide structure for transmitting signals from the RF chain, allowing the reconfigurable radiating element switching to the radiation state to couple the signal transmitted by the substrate-integrated waveguide structure into free space.

[0069] A single RF chain, managed by a Field-Programmable Gate Array (FPGA), connects to the ports of all reconfigurable radiating elements in the MFA, thereby controlling the switching states of all reconfigurable radiating elements in the array. This high degree of reconfigurability is particularly advantageous in Rayleigh fading environments, as the MFA can improve the signal-to-interference ratio (SIR) by dynamically selecting the most favorable radiation location. Compared to traditional FA technologies, the system proposed in this patent does not rely on multiple RF chains or mechanically moving chains, but instead uses only a single RF chain to collect spatially diverse information. By eliminating the need for multiple control ports, hardware complexity and overall system cost are significantly reduced.

[0070] For ease of computation, the MFA is constructed as a two-dimensional array of radiating elements uniformly distributed along two orthogonal axes. For each spatial dimension... The array contains There are elements, and these elements are in The length is evenly distributed. This configuration produces a total of Discrete units, of which , and The slots of the reconfigurable radiating element operate as magnetic dipoles, and the current induced by the waveguide causes a phase reversal between the upper and lower slots.

[0071] For those located The active element, and its associated phase shift are represented as follows:

[0072]

[0073] in Indicates the propagation distance within the waveguide. It is the propagation constant of the guided wave. By selectively activating these slits, the MFA can achieve fine-grained, programmable control over its radiation mode.

[0074] To achieve the communication and sensing objectives, during communication, the transmitter sends a signal to a specific user, while the MFA dynamically activates a subset of its N-port active antenna elements for signal reception, with all ports of the reconfigurable radiating elements connected to a single RF chain. For sensing, the system focuses on a Domain of Interest (DOI), which can be modeled as a two-dimensional (2D) region and discretized with spatial resolution. and A voxel grid. The total number of voxels in the region of interest is... ,in and These represent the number of spatial pixels along the x-axis and y-axis, respectively. Area of ​​each pixel. Each by The indexed voxels represent the local electromagnetic properties within the region of interest. The primary objective of sensing is to reconstruct the vector of relative permittivity contrast (reflection coefficient). It encodes the spatial electromagnetic properties required for high-resolution ISAC sensing, and this reconstruction can accurately locate scatterers within the DOI.

[0075] To facilitate mathematical analysis, the following mapping is used to convert the two-dimensional antenna position index of the MFA into a one-dimensional index:

[0076]

[0077] The mapping is performed row-wise, sequentially from left to right within each row; in a three-dimensional environment with rich scattering, the two arbitrary antenna positions on the MFA... and The spatial correlation between them was modeled using the Jake model, and the correlation coefficient of spatial correlation was obtained. Represented as:

[0078]

[0079] In the formula: For a zeroth-order Bessel function of the first kind, where k is the wavenumber; spatially separated. Defined as:

[0080]

[0081] Thus, the spatial correlation matrix is ​​obtained. The spatial correlation matrix is ​​decomposed into a unitary matrix and eigenvectors through eigenvalue decomposition, i.e.:

[0082]

[0083] In the formula: It is a unitary matrix. It contains feature values ​​arranged in descending order.

[0084] Based on equation (5), the transmitter and user can be connected. The channel link vector between them is modeled as follows:

[0085]

[0086] In the formula: For transmitters and users The channel link vector between them, which corresponds to the channel coefficient vector at all antenna positions of the MFA, is expressed as: ; For the corresponding user No. Channel coefficients for each active receiver location. Furthermore, This represents small-scale fading, modeled as a zero-mean, covariance matrix. A circularly symmetric complex Gaussian random vector.

[0087] In the multi-user integrated sensing and communication system based on a superfluid antenna proposed in this embodiment, dynamic reconfiguration can be performed using the FA (Feature Automated Communication) principle to simultaneously support sensing and communication. Within the same ISAC (Integrated Sensing and Communication System), the base station transmitter's FPA (Functional Peripheral Interface) uses shared hardware and spectrum to transmit composite communication waveforms carrying different user data to multiple users. Each transmission symbol in the composite communication waveform is used for both sensing and communication; that is, the composite communication waveform serves as both a sensing waveform and a communication waveform. Satisfying power constraints .

[0088] The ISAC system involved in this embodiment aims to achieve accurate target detection and localization while supporting multi-user communication. To this end, this embodiment transmits a composite communication waveform carrying data from different users via the transmitter's FPA. This composite communication waveform serves as both a communication waveform and a sensing waveform. As a communication waveform, it transmits signals to each communication user. As a sensing waveform, it illuminates the region of interest, where it interacts with scatterers to form scattered signals. The composite communication waveform in this embodiment simultaneously fulfills the requirements for multi-user data transmission and environmental detection, avoiding the detection overhead of configuring an independent radar system for the sensing function, thereby improving spectrum efficiency and hardware utilization.

[0089] The communication objective of this embodiment is to communicate with multiple users equipped with MFA using a transmitter based on the BS.

[0090] On the user receiving side, MFA can dynamically select and activate all A subset of communication-activated antenna elements in one of the available locations, denoted as .user The user obtains the corresponding symbol data from the received composite communication waveform by decoding a subset of activated antenna elements. Received communication signals The model is as follows:

[0091]

[0092] In the formula: Indicates the transmitter and user The channel coefficient of the nth active antenna port; Indicates targeting users Symbolic data, This refers to other users. The symbol data; the two symbol data have uniform transmission power, satisfying Noise item This represents Additive White Gaussian Noise (AWGN).

[0093] The sensing objective of this implementation is to reconstruct the spatial location and shape of a target scatterer within the region of interest using an FPA-based transmitter and an MFA-based receiver.

[0094] Assume the total electric field, incident electric field, and scattered electric field vectors of the transmitter are respectively expressed as: , and On the BS receiver side, the MFA can dynamically select and activate all A subset of sensing-activated antenna elements at available locations, denoted as When the receiver MFA's first When an activated reconfigurable radiating element operates as a transmitter with unit excitation, the electric field it emits is expressed as: .

[0095] As can be seen, the sensing function of this system is achieved through the process of transmitting signals and then receiving the target's scattered echoes, and its operation must conform to the basic principles of radar sensing. Based on the radar sensing model, the transmitter and receiver communicate via the ISAC channel of the DOI. It is given by the following formula:

[0096]

[0097] In the formula: For the receiver's first Channel response of an activated reconfigurable radiating element; and It is a normalization constant determined by the antenna. It encapsulates the scattering effect response caused by the target scatterer in the region of interest; the reflection coefficient vector. The electromagnetic properties of the scatterer within the DOI were characterized.

[0098] The sensed signal received at the MFA of the BS receiver is represented as:

[0099]

[0100] In the formula: This represents the AWGN in the perception process.

[0101] It is understood that the MFA-based multi-user integrated sensing and communication system provided in this embodiment aims to achieve accurate target detection and localization, while supporting multi-user communication.

[0102] Step 102: Adjust the sensing active antenna element subset of the receiver's MFA so that the receiver's MFA receives the scattered signal under different sensing active antenna element subsets; measure the received signal voltage of the receiver under different sensing active antenna element subsets.

[0103] It should be noted that the on / off state of the PIN diodes in the MFA is dynamically switched by FPGA programming, thereby controlling the activation state of all reconfigurable radiating elements in the MFA. Each time, a different subset of sensing active antenna elements is selected for element activation, forming multiple spatial receiving modes. In each mode, the same radio frequency link is used to receive scattered signals and record the receiver voltage value, providing a computational basis for subsequent target sensing.

[0104] Currently, in terms of existing sensing and reconstruction, the main challenges in effectively implementing MFA for ISAC applications are: reconstructing high-dimensional spatial information from limited MFA measurements. Traditional positioning methods (such as time of arrival, angle of arrival, etc.) are often hampered by multipath effects and operational complexity. Although the inverse scattering method shows promise, it has limitations in complex scattering environments and there is insufficient exploration of its integration with the MFA-ISAC system.

[0105] To address the aforementioned challenges, this embodiment utilizes the dynamic activation capability of MFA to support multiple measurement sensing, thereby managing inherent scattering effects; it integrates the inverse scattering method into the MFA-based ISAC framework, transforming the spatial sensing problem into a parameterized reconstruction problem of the electromagnetic properties of the target.

[0106] The following section discusses the feasibility of integrating the inverse scattering method into the MFA-based ISAC framework:

[0107] In the context of the inverse scattering method, the DOI is discretized into a grid of point-like scatterers, each defined by a specific reflectivity parameter. Grid points Total electric field from the transmitter Indicated as the incident field and scattered field The sum, according to the Lippmann-Schwinger integral principle, the scattered field is obtained through the reflection coefficient. The relationship with the total field is represented as follows:

[0108]

[0109] Because of direct measurement of each point in the DIO This is usually not feasible, therefore the scattered field is obtained through the receiver MFA. Indirect measurement using an activated reconfigurable radiation element. In the first... Each activated reconfigurable radiative element is located at the corresponding position. Scattered field observed at Represented as:

[0110]

[0111] In the formula: j= The imaginary unit is ω, and the angular frequency is ω. is the free space permeability; where, It is the Green's function represented by the Hankel function in the two-dimensional case.

[0112] Utilizing electromagnetic reciprocity, the Green's function can be expressed as the electric field radiated when a receiving antenna is used as a transmitter and operates with unit excitation. Instead, the received signal voltage measurable at the MFA of the activated receiver. Represented as:

[0113]

[0114] The main objective of the inverse problem is to solve the problem given only the receiver voltage measurement. Estimate under the circumstances .

[0115] Based on equations (8)-(9), under noise-free conditions, at the activated receptor position The radar sensing signal received at the location is represented as:

[0116]

[0117] Comparing the inverse scattering models in equation (13) and (12), their different emphases become apparent. The inverse scattering method emphasizes object parameters. The relationship between the transmitter and the receiver is considered, while the radar sensing model focuses on the relationship between the transmitter and the receiver. By rearranging the sensing channel equations in equation (8), it can be proven that these models are mathematically equivalent, i.e.:

[0118]

[0119] Substituting equation (14) into equation (13), and restating the equation for all activated receiving positions, we obtain the radar sensing signal in equation (14) as follows:

[0120]

[0121] Since the perception objective is to estimate the normalization And for scalars Normalization and This will produce equivalent results, that is, the perception process of the multi-user integrated sensing and communication system involved in this embodiment described from the radar aspect (Equation (15)) and from the inverse scattering aspect (Equation (12)) is mathematically equivalent, thus providing a unified theoretical framework for the MFA-based multi-user ISAC system; or, in the MFA-based multi-user ISAC system framework provided in this embodiment, the signal received by the radar perception model is mathematically equivalent to the signal obtained by inverse scattering measurement of the same target. This equivalence enables the inverse scattering algorithm to be seamlessly integrated into the MFA-based multi-user ISAC system, thereby enhancing the perception capability of the MFA-based multi-user ISAC system.

[0122] Step 103: Based on the inverse scattering algorithm, the reflection coefficient is estimated according to the voltage of multiple received signals, and the scattering body in the region of interest is identified by the reflection coefficient to achieve sensing.

[0123] It should be noted that, based on the inverse scattering algorithm, a linear relationship between the received signal voltage obtained from multiple measurements and the reflection coefficient is constructed, thereby estimating the reflection coefficient; this embodiment can estimate the reflection coefficient from a finite number of measurements, and reconstruct the spatial position and shape of the scatterer in the region of interest using the reflection coefficient.

[0124] In one specific implementation, step 103 may include the following steps:

[0125] S11. Based on the inverse scattering algorithm, calculate the measurement vector under different subsets of sensing active antenna elements, and establish a sensing model of the received signal voltage and measurement vector under different subsets of sensing active antenna elements.

[0126] S12. Using compressed sensing and a two-step iterative shrinking threshold algorithm, the reflection coefficient is estimated based on the sensing model;

[0127] S13. Identify scatterers in the region of interest using the reflection coefficient to achieve perception.

[0128] It should be noted that the inverse scattering problem in equation (12) is inherently more challenging than the forward scattering problem because it typically involves fewer measurements than unknowns, making the problem ill-posed and nonlinear. To address this challenge, this specific embodiment employs the Born approximation algorithm. Under the Born approximation algorithm, the total electric field is approximated by the incident electric field, and the calculated electromagnetic measurement vector is used to approximate the total electric field. The inverse scattering problem in equation (12) is simplified to establish a sensing model between the received signal voltage, the electromagnetic measurement vector, and the reflection coefficient, namely:

[0129]

[0130] In the ISAC system described in this embodiment, sensed information can be encoded into a set of measurements by generating different radiation fields. This is achieved by activating different subsets of sensed active antenna elements on the MFA. This is achieved by creating different radiation patterns within the DOI.

[0131] Therefore, by collecting measurements from L different subsets of sensing active antenna elements, the sensing model in the noise-free case is as follows:

[0132]

[0133] In the formula: It is a voltage vector formed by the received signal voltages under different subsets of sensing-activated antenna elements, and each element of it is a voltage vector. As defined in equation (16); and the electromagnetic measurement matrix The structure is It is formed by measurement vectors from L subsets of different sensing-activated antenna elements.

[0134] Since the number of measurements is much smaller than the number of pixels in the region of interest, i.e. So from Reconstructing the reflection coefficient vector This becomes an ill-posed inverse problem. Therefore, we can directly invert the measurement matrix. This is not feasible. Therefore, this specific embodiment employs compressed sensing (CS) technology, which can utilize… The sparsity of the problem allows us to reformulate it as a sparse reconstruction problem, namely:

[0135]

[0136] In the formula: express Norm.

[0137] To further optimize and solve the aforementioned sparse reconstruction problem, this specific embodiment employs a two-step iterative shrinkage thresholding (TwIST) algorithm to solve the sparse reconstruction problem, thereby estimating the reflection coefficient. TwIST is a robust and efficient method for sparse signal recovery, which iteratively optimizes the scheme through shrinkage and thresholding operations.

[0138] Step 104: Calculate the FPA of the transmitter and the channel link vector of each user. Based on the preset signal-to-interference ratio threshold and the channel link vector, determine the optimal antenna activation mode of each user's MFA, thereby controlling the switching state of multiple reconfigurable radiating elements between radiating and non-radiating states, and obtaining the optimal subset of communication active antenna elements for each user.

[0139] It should be noted that during the communication phase, attention needs to be paid to interference limiting mechanisms, including interference power. Significantly exceeds noise power ,Right now Therefore, noise can be ignored in communication analysis. To evaluate communication quality and quantify the impact of interference, this embodiment uses the signal-to-interference ratio (SIR) as the main performance indicator, and determines the optimal antenna activation mode for each user's MFA based on the transmitter's FPA and the channel link vector of each user.

[0140] In one specific implementation, step 104 may include the following steps:

[0141] S21. Calculate the FPA of the transmitter and the channel link vectors of each user;

[0142] S22. Based on the SRMPA algorithm, multiple candidate antenna activation modes are generated by searching according to the preset antenna activation mode and the preset iteration threshold; the signal-to-interference ratio of different antenna activation modes is calculated iteratively according to the channel link vector and multiple antenna activation modes.

[0143] S23. If the calculated signal-to-interference ratio (SIR) is greater than or equal to the preset SIR threshold, then the antenna activation mode corresponding to the first SIR that is greater than the preset SIR threshold is taken as the best antenna activation mode; if the number of calculation iterations reaches the preset iteration threshold and the calculated SIR is less than the preset SIR threshold, then the antenna activation mode corresponding to the largest calculated SIR is taken as the best antenna activation mode.

[0144] S24. Based on the optimal antenna activation mode of each user's MFA, control multiple reconfigurable radiating elements to switch between radiating and non-radiating states to obtain the optimal subset of communication active antenna elements for each user.

[0145] It is understandable that the SIR achieved by each user is directly dependent on the antenna activation mode vector. The selection of the activation antenna location is determined. Therefore, the main objective of this specific embodiment is to find an activation mode that maximizes the desired user SIR. This leads to the following optimization problem:

[0146]

[0147] In the formula: Let be the radiation response vector of the MFA; where, , Let be the phase response vector determined by the physical structure of the antenna with N controllable radiating elements. ,in Indicates by position The phase response is determined by the physical structure of the antenna; ⊙ represents element-wise multiplication, that is, multiplying corresponding elements of two vector matrices. A value of 0 indicates that the Nth controllable radiating element is in a non-radiating state. A value of 1 indicates that the object is in a radiating state.

[0148] However, for larger N values, it requires an exhaustive search of all 2N possible antenna activation modes, making direct solution of equation (19) computationally infeasible. Furthermore, the optimization problem is non-convex and involves fractional forms, which further complicates the optimization procedure.

[0149] To address this challenge, this specific embodiment introduces the Single RF Multi-Pattern Activation (SRMPA) method. In SRMPA, the optimization strategy does not seek a globally optimal solution, but rather aims to find any solution that satisfies a preset SIR threshold. The activation mode. If the SIR of a given user u exceeds the threshold. If this is achieved, the interference is effectively suppressed, ensuring reliable communication. This transforms the original optimization problem (19) into a feasibility search problem, specifically:

[0150]

[0151] Although the feasibility search problem remains combinatorial, the reformulation allows equation (20) to use a randomized search strategy. Specifically, a preset SIR threshold is first initialized. Set a preset iteration threshold Then, a preset antenna activation mode is defined. Next, random binary candidate antenna activation modes are generated based on the SRMPA algorithm, with each activation mode corresponding to a different antenna configuration.

[0152] For each antenna activation mode, the SIR for that antenna activation mode is calculated based on the transmitter's FPA and the channel link vectors of each user, i.e.:

[0153]

[0154] In the formula: The signal-to-interference ratio for user u;

[0155] If the calculation yields Greater than or equal to the preset signal-to-interference ratio threshold If the number of iterations reaches a preset iteration threshold, the corresponding mode is immediately selected as the optimal antenna activation mode and the search is terminated. If the calculated signal-to-interference ratio (SIR) is less than the preset SIR threshold, then the antenna activation mode corresponding to the largest SIR calculated in all test configurations is selected as the optimal antenna activation mode.

[0156] This specific embodiment proposes an SRMPA FAMA scheme, which achieves a balance between computational efficiency and communication performance by employing a finite search approach, avoiding exhaustive search while ensuring reliable operation in multi-user scenarios with limited re-interference. Based on the SRMPA algorithm, the antenna activation mode is determined adaptively through randomization, effectively reducing hardware complexity, eliminating the requirement for multiple RF chains, and effectively addressing the challenges of combinatorial optimization.

[0157] Step 105: The composite communication waveform is received by each user's MFA based on the corresponding optimal set of active antennas, and the transmission symbol data of each user is obtained by decoding the composite communication waveform to realize communication.

[0158] It should be noted that each user's MFA optimizes reception conditions based on its corresponding optimal set of active antennas, thereby effectively suppressing multi-user interference and achieving reliable communication demodulation. Under optimal configuration, each user's MFA receives the composite communication waveform transmitted by the base station transmitter and decodes the corresponding transmission symbol data through standard communication. In this embodiment, each user can autonomously suppress interference from other users on the same channel, thereby significantly improving the quality of received signals in strong interference multi-user scenarios and achieving reliable and efficient multi-user communication.

[0159] Please see Figures 4-8 This invention also provides corresponding full-wave electromagnetic simulation experiments to verify the application performance of the proposed solution. Specifically, this example uses a high-fidelity three-dimensional electromagnetic analysis platform (such as CST StudioSuite) to perform full-wave electromagnetic simulation, constructing a complete ISAC system model. The simulation accurately captures basic 3D electromagnetic effects, thereby verifying the sensing and communication functions of the MFA-based ISAC framework proposed in this invention. Simultaneously, it utilizes the dynamic radiation characteristics of the MFA to achieve the electromagnetic diversity required for simultaneous high-performance sensing and communication. First, the sensing capability is evaluated by analyzing the characteristics of the measurement matrix and the effectiveness of the reconstruction process. Second, the communication performance is evaluated using key indicators supported by extensive Monte Carlo simulations and full-wave analysis.

[0160] 1) Perceptual ability assessment

[0161] This example uses sensing capacity, a key metric, to quantitatively evaluate the sensing performance of the proposed system. Through... Singular Value Decomposition (SVD) is performed. The perceptual capacity increases with the number of significant singular values, reflecting a better perceptual diversity. This metric provides a comprehensive measure of the overall perceptual capability of the system.

[0162] The constructed system model operates at a carrier frequency of 26.5 GHz (λ = 11.3 mm), and the sensing scene is a DOI with dimensions of 54 × 40 mm² (4.87λ × 3.54λ). The transmitter and receiver at the BS are 6 mm (0.53λ) apart, and both are 30 mm (2.65λ) away from the DOI, ensuring operation within the Fresnel region. The DOI is discretized into... Each pixel represents One unknown. The electric field collected within the DOI is used to construct... The SVD allows for subsequent reconstruction of the reflection coefficient (relative permittivity contrast). .

[0163] Through analysis SVD assessment of perceptual diversity, such as Figure 4 As shown, the amplitude distribution of the radiation field (e.g.) Figure 4 (a) and phase distribution (e.g.) Figure 4 (b) reveals variations in both spatial samples and measurements, which ensure measurement independence and improve perception accuracy. Normalized SVD spectra (such as...) Figure 4 (c) shows that at an SNR of 20 dB, approximately 37 dominant singular values ​​are above the threshold of 0.1, close to the total of 40 available measurement modes, indicating that the utilization of mode diversity is close to optimal. Therefore, increasing the number of active modes beyond this point may yield diminishing returns, as the spatial diversity provided by the MFA is sufficient to mitigate reconstruction ambiguity even in underdetermined scenarios. Figure 4 Figure (d) shows the curve of sensing capacity as a function of signal-to-noise ratio (SNR). This curve quantitatively reflects the rate of sensing information that the system can acquire under different SNR conditions. The sensing capacity increases with the increase of SNR, which verifies the effectiveness of the system design, that is, under given hardware and measurement mode constraints, it can efficiently convert signal power into sensing information.

[0164] To evaluate the system's perceptual performance, this example uses three different scatterer configurations. Each configuration uses copper as the scatterer material, with varying numbers and sizes. Peak Signal-to-Noise Ratio (PSNR) and Structural Similarity Index Measure (SSIM) are used to evaluate reconstruction performance. Higher PSNR values ​​or SSIM values ​​closer to 1 indicate better image reconstruction quality. This example primarily focuses on the second and third configurations, namely the reconstruction of a single large object and the reconstruction of two identical scatterers.

[0165] The second configuration involves a single rectangular scatterer with dimensions of 10 mm (0.88λ) in length and 5 mm (0.44λ) in width. The reconstruction result is as follows. Figure 5 As shown, the white dashed line represents the true boundary of the scatterer, and the normalized amplitude of the reconstructed reflectance is displayed on the color bar. Figure 5 The true situation in (a) and Figure 5 Comparing the reconstruction results in (b), the reconstruction results are highly consistent with the actual situation, achieving a PSNR of 19.59dB and an SSIM of 0.91. It can be seen that the ISAC system proposed in this invention successfully captured a large scatterer structure, confirming its ability to process objects with increased spatial size.

[0166] In the third configuration, the reconstruction capability of two identical scatterers is primarily examined, with each scatterer having a square profile with a width of 5 mm (0.44λ). Figure 6 As shown, Figure 6 The true situation in (a) and Figure 6 Comparing the reconstruction results in (b), both scatterers were effectively reconstructed and correctly identified, and their positions closely matched their true positions. The system achieved a PSNR of 17.89 dB and an SSIM of 0.86, demonstrating its ability to resolve multiple objects within a DOI.

[0167] In summary, simulation results validate the effectiveness of the MFA-based multi-user ISAC system proposed in this invention for reconstructing the reflectivity of objects within a DOI. By leveraging the dynamic radiometric capabilities of MFA, the system achieves robust performance across various object configurations, producing high-quality reconstruction results with minimal ambiguity. Therefore, the MFA-supporting multi-user ISAC framework proposed in this invention can be considered a competitive technology for accurate perception in underdetermined scenes.

[0168] 2) Communication performance evaluation

[0169] To evaluate the communication performance of the system, this example employs extensive Monte Carlo simulations, focusing on outage probability and multiplexing gain. These metrics are crucial for assessing the robustness and spectral efficiency of the system in multi-user scenarios, particularly under interference-constrained conditions; subsequently, a comprehensive full-wave electromagnetic simulation is performed based on the theoretical analysis of this model.

[0170] With 5 communication users, the performance of the SRMPA scheme (i.e., SRMPA FAMA scheme) proposed in this invention is compared with that of the existing Standard Maximum Ratio Combining FASystem (FAS-MRC) and the existing Slow FAMA using static single-position activation. Figure 7 (a) shows the performance analysis of the outage probability versus the SIR threshold for the SRMPA FAMA scheme, the FAS-MRC scheme, and the Slow FAMA scheme. Figure 7 (b) presents a performance analysis of the multiplexing gain versus the SIR threshold for the SRMPAFAMA, FAS-MRC, and Slow FAMA schemes. Figure 7 As can be observed, the proposed system scheme consistently outperforms the FAS-MRC and Slow-FAMA schemes at higher SIR thresholds. Therefore, this scheme balances high performance, scalability, and hardware simplicity, making it a highly attractive solution for next-generation wireless networks.

[0171] To verify the theoretical analysis based on the system model, comprehensive electromagnetic wave simulations were conducted. These system models modeled the entire system under actual Rayleigh fading channel conditions. This example uses CST Studio Suite 2024 to analyze and statistically analyze a total of 500 fading channel instances under 300 multi-frequency omnidirectional antenna activation modes. Based on the MFA-based multi-user ISAC technology proposed in this invention, a comprehensive full-wave analysis was performed, validating the theoretical model and performance predictions of the proposed system in a real electromagnetic field environment. Figure 8 (a) shows the performance analysis of the outage probability and SIR threshold between CST simulation experiments (CST Verification) and theoretical models under actual electromagnetic field environments, while Figure 8(b) presents a performance analysis of the multiplexing gain and SIR threshold between CST simulation experiments and theoretical models under actual electromagnetic field conditions. Figure 8 It can be observed that the CST simulation results based on the MFA-based multi-user ISAC technology proposed in this invention show a trend that is basically consistent with the theoretical predictions, providing strong evidence for the accuracy and reliability of the analysis model. Therefore, the MFA-based multi-user ISAC system proposed in this invention can serve as a reliable and efficient solution for next-generation wireless communication networks. Furthermore, based on the fitting results between theory and practical application, this system provides a promising approach for achieving robust and efficient communication in complex and dynamic environments.

[0172] This invention provides a multi-user integrated sensing and communication method based on a superfluid antenna (MFA), which combines sensing and communication capabilities, balancing interference suppression, communication throughput, and sensing accuracy, aiming to simultaneously support sensing and communication. This invention has the following advantages:

[0173] 1. This invention proposes a multi-user ISAC system based on MFA (Multi-Functional Facing), which overcomes the hardware limitations of traditional FA implementations. The MFA design integrates PIN diodes into the SIW (Single Injection Wave) and achieves dynamic, multi-location antenna activation through a single RF chain. Four PIN diodes control the selective activation of each element, ensuring efficient radiation from active elements while preventing radiation from other elements. This invention combines programmable metasurfaces and FA principles to achieve dynamic reconfiguration of antenna elements to optimize performance, without relying on complex signal processing, providing technical support for the system's sensing and communication capabilities.

[0174] 2. To address the challenge of reconstructing high-dimensional spatial information from limited measurements, this invention employs a sparse-driven inverse scattering algorithm to actively utilize scattering effects to generate beneficial interference nulls. By introducing a compressed sensing algorithm, it achieves the reconstruction of scatterer information from limited measurements. Applying inverse scattering technology to an MFA-based multi-user ISAC system effectively solves the limitations of traditional positioning methods in complex environments, providing accurate and robust spatial reconstruction capabilities.

[0175] 3. In complex environments, existing FA technologies struggle to achieve reliable interference suppression without relying on complex precoding or interference cancellation mechanisms. To address this, this invention combines the SRMPA scheme to search for the optimal antenna activation mode. Under the optimal antenna activation mode, interference from other users can be effectively suppressed, ensuring the reliability of multi-user communication. At the same time, it can intelligently manage multi-user interference without complex precoding or additional RF chains.

[0176] The apparatus for verifying the validity of web page links provided in the embodiments of this application will be described below. The apparatus for verifying the validity of web page links described below can be referred to in correspondence with the method for verifying the validity of web page links described above.

[0177] Please see Figure 9 The present invention also provides a multi-user integrated sensing and communication device based on a superfluid antenna, the device comprising:

[0178] Transmitting module 201 is used to transmit a composite communication waveform carrying different user data through the FPA of the transmitter; and to irradiate the region of interest with a scattered signal formed by the composite communication waveform.

[0179] The receiver receiving module 202 is used to adjust the sensing active antenna element subset of the receiver's MFA so that the receiver's MFA receives the scattered signal under different sensing active antenna element subsets; and to measure the received signal voltage of the receiver under different sensing active antenna element subsets.

[0180] The sensing module 203 is used to estimate the reflection coefficient based on multiple received signal voltages using an inverse scattering algorithm, and to identify the scattering body in the region of interest through the reflection coefficient to achieve sensing.

[0181] User activation selection module 204 is used to calculate the FPA of the transmitter and the channel link vector of each user. Based on the preset signal-to-interference ratio threshold and the channel link vector, it determines the optimal antenna activation mode of each user's MFA, thereby controlling the switching state of multiple reconfigurable radiating elements between radiating and non-radiating states, and obtaining the optimal subset of communication active antenna elements for each user.

[0182] The communication module 205 is used to receive composite communication waveforms through each user's MFA based on the optimal subset of communication active antenna elements for each user, and to decode the composite communication waveforms to obtain the transmission symbol data of each user in order to achieve communication.

[0183] The present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of any of the above-described multi-user integrated sensing and communication methods based on a superfluid antenna.

[0184] The present invention also provides a computer-readable storage medium having a computer program or instructions stored thereon, wherein the computer program or instructions, when executed by a processor, implement the steps of any of the above-mentioned multi-user integrated sensing and communication methods based on a superfluid antenna.

[0185] The present invention also provides a computer program product, including a computer program or instructions, characterized in that, when the computer program or instructions are executed by a processor, they implement the steps of any of the above-mentioned multi-user integrated sensing and communication methods based on a superfluid antenna.

[0186] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0187] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0188] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0189] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0190] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0191] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-user integrated sensing and communication method based on a superfluid antenna, characterized in that, The method is applied to a multi-user integrated sensing and communication system based on a superfluid antenna, the system including a region of interest, a transmitter equipped with an FPA, a receiver equipped with an MFA, and multiple users equipped with MFAs; the MFA includes multiple reconfigurable radiating elements; the method includes: A composite communication waveform carrying different user data is transmitted via the FPA of the transmitter; the composite communication waveform is used to illuminate the region of interest to form a scattered signal. Adjust the sensing-activated antenna element subset of the receiver's MFA so that the receiver's MFA receives the scattered signal under different sensing-activated antenna element subsets; measure the received signal voltage of the receiver under different sensing-activated antenna element subsets; The reflection coefficient is estimated based on multiple received signal voltages using an inverse scattering algorithm, and the scattering body in the region of interest is identified by the reflection coefficient to achieve sensing. Calculate the FPA of the transmitter and the channel link vector of each user. Based on the preset signal-to-interference ratio threshold and the channel link vector, determine the optimal antenna activation mode of each user's MFA, thereby controlling the switching state of multiple reconfigurable radiating elements between radiating and non-radiating states, and obtaining the optimal subset of communication active antenna elements for each user. Based on the optimal subset of communication active antenna elements for each user, the composite communication waveform is received through the MFA of each user, and the transmission symbol data of each user is obtained by decoding the composite communication waveform to realize communication.

2. The multi-user integrated sensing and communication method according to claim 1, characterized in that, The step of estimating the reflection coefficient based on multiple received signal voltages using an inverse scattering algorithm, and identifying the scatterer in the region of interest using the reflection coefficient to achieve sensing, includes: Based on the inverse scattering algorithm, the electromagnetic measurement vector of the receiver is calculated under different subsets of sensing active antenna elements, and a sensing model of the received signal voltage and electromagnetic measurement vector under different subsets of sensing active antenna elements is established. The reflection coefficient is estimated based on the sensing model using compressed sensing and a two-step iterative shrinking threshold algorithm. The scatterer in the region of interest is identified by the reflection coefficient to achieve perception.

3. The multi-user integrated sensing and communication method according to claim 1, characterized in that, The steps of calculating the FPA of the transmitter and the channel link vectors of each user, determining the optimal antenna activation mode of each user's MFA based on a preset signal-to-interference ratio (SIR) threshold and the channel link vectors, thereby controlling the switching state of multiple reconfigurable radiating elements between radiating and non-radiating states, and obtaining the optimal subset of communication active antenna elements for each user, include: Calculate the FPA of the transmitter and the channel link vectors of each user; Based on the SRMPA algorithm, multiple candidate antenna activation modes are generated by searching according to a preset antenna activation mode and a preset iteration threshold; the signal-to-interference ratio of different antenna activation modes is calculated iteratively based on the channel link vector and the multiple antenna activation modes. If the calculated signal-to-interference ratio (SIR) is greater than or equal to a preset SIR threshold, then the antenna activation mode corresponding to the first SIR greater than the preset SIR threshold is taken as the optimal antenna activation mode; if the number of calculation iterations reaches the preset iteration threshold and the calculated SIR is less than the preset SIR threshold, then the antenna activation mode corresponding to the largest calculated SIR is taken as the optimal antenna activation mode. Based on the optimal antenna activation mode of each user's MFA, multiple reconfigurable radiating elements are controlled to switch between radiating and non-radiating states, thereby obtaining the optimal subset of communication active antenna elements for each user.

4. The multi-user integrated sensing and communication method according to claim 1, characterized in that, The MFA also includes a substrate-integrated waveguide structure and a PIN diode; The reconfigurable radiating element is disposed on the upper layer of the substrate integrated waveguide structure and is electromagnetically coupled to the substrate integrated waveguide structure; The PIN diode is embedded in the substrate integrated waveguide structure and is located at the circuit connection between the reconfigurable radiating element and the substrate integrated waveguide structure, and is used to control the reconfigurable radiating element to switch to a radiating state or a non-radiating state. Each of the MFAs is connected to the radio frequency chain through the substrate integrated waveguide structure for transmitting signals from the radio frequency chain, so that the reconfigurable radiating element switched to the radiating state couples the signal transmitted by the substrate integrated waveguide structure into free space.

5. The multi-user integrated sensing and communication method according to claim 2, characterized in that, The received signal voltage is expressed as: In the formula: The measured received signal voltage; To sense and activate a subset of antenna elements, j= The imaginary unit is ω, and the angular frequency is ω. Permeability in free space and All are normalized constants; For the first The electric field of an activated reconfigurable radiative element; The total electric field from the transmitter at the region of interest; This is the reflection coefficient vector; The electromagnetic measurement vector is represented as follows: In the formula: This is the electromagnetic measurement vector; The sensing model of the received signal voltage and the electromagnetic measurement vector is expressed as follows: In the formula: The reflection coefficient; The sensing model of the received signal voltage versus the measurement vector under different subsets of sensing activated antenna elements is then expressed as: In the formula: The voltage vector formed by the received signal voltage under different subsets of sensing activated antenna elements; The measurement matrix is ​​formed by the measurement vectors under different subsets of sensing activated antenna elements.

6. The multi-user integrated sensing and communication method according to claim 3, characterized in that, The signal-to-interference ratio is calculated as follows: In the formula: The signal-to-interference ratio for user u; Let be the radiation response vector of the MFA; Let FPA be the channel link vector between the transmitter and user u; For the set of all users; in, In the formula: Antenna activation mode, N is the number of controllable radiation elements in the MFA. A value of 0 indicates that the Nth controllable radiating element is in a non-radiating state. A value of 1 indicates that the object is in a radiating state. The phase response vector is determined by the physical structure of the antenna with N controllable radiating elements; This is an element-wise multiplication operation.

7. A multi-user integrated sensing and communication device based on a superfluid antenna, characterized in that, The device includes: The transmitting module is used to transmit a composite communication waveform carrying different user data through the FPA of the transmitter; and to irradiate the region of interest with the composite communication waveform to form a scattered signal. A receiver receiving module is used to adjust the sensing active antenna element subset of the receiver's MFA so that the receiver's MFA receives the scattered signal under different sensing active antenna element subsets; and to measure the received signal voltage of the receiver under different sensing active antenna element subsets. The sensing module is used to estimate the reflection coefficient based on multiple received signal voltages using an inverse scattering algorithm, and to identify the scattering body in the region of interest through the reflection coefficient to achieve sensing. The user activation selection module is used to calculate the FPA of the transmitter and the channel link vector of each user. Based on the preset signal-to-interference ratio threshold and the channel link vector, it determines the optimal antenna activation mode of each user's MFA, thereby controlling the switching state of multiple reconfigurable radiating elements between radiating and non-radiating states, and obtaining the optimal subset of communication active antenna elements for each user. The communication module is used to receive the composite communication waveform through the MFA of each user based on the optimal subset of communication activation antenna elements for each user, and to decode the composite communication waveform to obtain the transmission symbol data of each user in order to realize communication.

8. A computer device, comprising a memory, a processor, and a computer program stored in the memory, characterized in that, The processor executes the computer program to implement the steps of the multi-user integrated sensing and communication method based on a superfluid antenna as described in any one of claims 1-6.

9. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed by the processor, they implement the steps of the multi-user integrated sensing and communication method based on a superfluid antenna as described in any one of claims 1-6.

10. A computer program product, comprising a computer program or instructions, characterized in that, When the computer program or instructions are executed by the processor, they implement the steps of the multi-user integrated sensing and communication method based on a superfluid antenna as described in any one of claims 1-6.

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