Transmission-type reconfigurable intelligent metasurface energized cooperative sensing and space alignment method and transmission-type reconfigurable intelligent metasurface energized cooperative sensing and space alignment system

Abstract

The invention provides a transmission-type reconfigurable intelligent metasurface energized cooperative sensing and space alignment method and system, and the method comprises the steps: S1, solving a plurality of transmission-type reconfigurable intelligent metasurface transceiver TRIS beam forming matrix generation control signals through a controller through employing a block coordinate descent algorithm, the control signal is loaded to the transmission panel to control the amplitude and the phase of the transmission panel; s2, according to the amplitude and the phase of the transmission panel, transmitting a single-tone carrier signal based on a horn antenna to realize beam forming, and transmitting a formed beam to target user equipment; s3, optimizing a beam forming matrix and sensing beam scheduling under the condition of response error constraint and power constraint of the TRIS beam forming matrix so as to enable a plurality of transmission-type reconfigurable intelligent super-surface transceivers TRIS to realize accurate sensing and cooperative sensing area space alignment on the same target user equipment; the transmission-type reconfigurable intelligent super-surface transceiver TRIS comprises a plurality of transmission units, a controller and a horn antenna.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless communications, and in particular, to a collaborative sensing and spatial alignment method and system enabled by a transmissive reconfigurable intelligent metasurface, and more particularly, to a collaborative sensing resource allocation and spatial alignment method enabled by a transmissive reconfigurable intelligent metasurface transceiver. Background Art

[0002] Collaborative sensing technology can overcome the limitations of single-node sensing. By sharing information and collaborating across multiple nodes, it enhances sensing accuracy, reliability, and coverage. In complex wireless environments, multi-node collaboration enables more comprehensive acquisition of environmental information, improving target detection, tracking, and identification capabilities. This is crucial for applications such as intelligent transportation and environmental monitoring. Precise spatial registration enables precise spatial matching of sensor information from each node, avoiding errors during information fusion and ultimately improving overall sensing performance.

[0003] Transmissive reconfigurable smart surface (TRIS), an emerging technology, can significantly optimize signal propagation quality and enhance communication and sensing capabilities through intelligent manipulation of the wireless environment. It can flexibly change the amplitude, phase, and polarization characteristics of the signal, enabling large-scale antenna transmission with a narrower beamwidth, effectively reducing interference. Furthermore, TRIS can be deployed as a relay within the coverage area of ​​existing base stations (BSs), eliminating coverage blind spots, expanding service coverage, ensuring stable access for edge devices, and creating favorable conditions for collaborative sensing. Furthermore, its low power consumption significantly reduces energy consumption and deployment costs, making it suitable for addressing the challenges facing future networks.

[0004] Existing research lacks clarity on collaborative mechanisms and primarily focuses on optimizing a single TRIS, without considering the spatial alignment of collaborative areas. This paper proposes a collaborative sensing system and spatial alignment method powered by a transmissive, reconfigurable intelligent metasurface transceiver. By optimizing the beamforming matrix and sensing beam scheduling, the collaborative sensing system demonstrates superior sensing performance compared to a single TRIS configuration. Summary of the Invention

[0005] In view of the defects in the prior art, the purpose of the present invention is to provide a collaborative perception and spatial alignment method and system enabled by a transmissive reconfigurable intelligent metasurface.

[0006] According to the present invention, a collaborative sensing and spatial alignment method enabled by a transmissive reconfigurable intelligent metasurface is provided, comprising:

[0007] Step S1: The controller uses a block coordinate descent algorithm to solve the TRIS beamforming matrix of multiple transmissive reconfigurable intelligent metasurface transceivers to generate control signals, and loads the control signals onto the transmissive panel to control the amplitude and phase of the transmissive panel;

[0008] Step S2: Based on the amplitude and phase of the transmission panel, a single-tone carrier signal is transmitted via a horn antenna to implement beamforming, and the formed beam is transmitted to the target user equipment;

[0009] Step S3: Optimizing the beamforming matrix and sensing beam scheduling under the conditions of response error constraints and power constraints of the TRIS beamforming matrix, so that multiple transmissive reconfigurable smart metasurface transceivers TRIS can achieve precise sensing of the same target user equipment and spatial alignment of the collaborative sensing area;

[0010] The transmissive reconfigurable intelligent metasurface transceiver TRIS includes: a plurality of transmission units, a controller and a horn antenna.

[0011] Preferably, the step S1 includes:

[0012]

[0013] Among them, A n Indicates amplitude; Indicates phase; x k Indicates a control signal.

[0014] Preferably, the power constraints of the TRIS beamforming matrix include:

[0015]

[0016] in,[·] nn Indicates taking the diagonal elements of the matrix, P t Indicates the maximum transmit power of the TRIS element, W k represents the beamforming matrix of the kth TRIS, represents the conjugate transpose of the kth TRIS beamforming matrix, the subscript n represents the element index of TRIS, and the subscript k represents the TRIS transceiver index.

[0017] Preferably, the response error constraint of the beamforming matrix includes:

[0018] The cooperative sensing area CSA is approximated as a plane parallel to the ground and expressed in polar coordinates as

[0019] rcosθ=hR k,m cosθ k,m ,

[0020] Where h is the height of TRIS, R k,m represents the distance between the target and TRIS, (θ k,m , ) represents the angle of the beam center; r represents the polar diameter in polar coordinates;

[0021] For small and distant targets that meet the preset requirements, the beam is approximated as an oblique cylinder with an elliptical base, which is expressed in polar coordinates as:

[0022]

[0023] Among them, (Δθ k,m , ) represents the beam width, θ rot =θ-θ k,m -π / 2 represents the projection of the angle between the beam center and the target on the horizontal plane;

[0024] Combining the above CSA and beam solving, the sensing area is an ellipse, whose major and minor axes are expressed as:

[0025]

[0026] In order to keep the cooperative sensing units consistent, the sensing units are approximated as circles. Then there are

[0027]

[0028] In order to make all sensor units of equal size, the target distance R obtained in the first stage is k,m Sort and use the median (R0,θ0, Δθ0, ) as a reference;

[0029]

[0030] According to the k,m and The beam width is adjusted by the formula, and the size of the sensing unit will remain unchanged;

[0031] Defining the angle vector and The element spacings are Δ1 and Δ2 respectively; the directional amplitude response required for the kth TRIS is expressed as:

[0032]

[0033] where Δθ is Δθ k,m The abbreviation of yes The abbreviation of represents the set of all desired signal directions; takes the direction of the AP into account; sets the beam width of different targets to be the same; sets r ad Reorganize into a matrix in angle index order

[0034] The steering matrix of the kth TRIS is defined as:

[0035]

[0036] Among them, A k represents the steering matrix of the kth TRIS; a l (·) represents the steering vector; θ k,l represents the pitch angle of the kth TRIS with respect to path l, represents the azimuth of the kth TRIS with respect to path l, represents the complex space, N represents the number of elements in TRIS, and L represents the number of paths;

[0037] Then, the directional response of the antenna after beamforming is expressed as:

[0038] r k =(W k ) H A k ,

[0039] Where, the superscript H represents the conjugate transpose, and W k represents the beamforming matrix of the kth TRIS, r k represents the directional response of the antenna after beamforming;

[0040] Finally, to ensure spatial alignment performance, the following response error constraints of the beamforming matrix need to be met:

[0041]

[0042] Where K represents the number of TRIS transceivers, represents the conjugate transpose of the direction response vector received by the kth TRIS, r k represents the direction response vector received by the kth TRIS, represents the directional amplitude response required for the kth TRIS Reorganize into a matrix in the order of angle index, γ th Indicates the threshold of spatial registration error.

[0043] Preferably, step S3 includes:

[0044] By optimizing the beamforming matrix W k and sensing beam scheduling ρ k, to maximize the minimum echo signal-to-noise ratio, the optimization problem is expressed as

[0045]

[0046] r k =(W k ) H A k .

[0047] Where k represents the TRIS index, W k represents the beamforming matrix of the kth TRIS, ρ k represents the kth TRIS sensing beam scheduling variable, m represents the target index, represents the signal-to-interference-plus-noise ratio of the kth TRIS echo about the mth target;

[0048] Introducing the auxiliary variable t, and relaxing the scheduling variables to continuous variables for ease of processing, the problem (P0) can be written as

[0049]

[0050] r k =(W k ) H A k .

[0051] in, Represents the perceptual scheduling variable ρ k relaxation;

[0052] Decoupling the problem (P1), given the sensing beam scheduling variables and beamforming matrix, the original problem can be written as

[0053]

[0054] Given the beamforming matrix and auxiliary variables, optimize the perceptual beam scheduling variable ρ k , then the problem is written as

[0055] (P3)findρ k ,

[0056]

[0057] Among them, the constraints is non-convex, transform it into the following form

[0058]

[0059] in, z k,m,irepresents the channel from the kth TRIS to the mth target and finally to the i-th TRIS, represents the conjugate transpose of the channel from the kth TRIS to the mth target and finally to the i-th TRIS, t represents the auxiliary variable to be solved, represents the relaxed sensing beam scheduling variable of the kth TRIS with respect to target j (j≠m), z k,j,i represents the channel from the kth TRIS to the jth target and finally to the i-th TRIS, represents the conjugate transpose of the channel from the kth TRIS to the jth target and finally to the i-th TRIS, represents the Gaussian white noise variance at the kth TRIS;

[0060] After solving problem (P3), we obtain the beamforming matrix and use the semidefinite programming (SDP) to solve the following problem:

[0061]

[0062] Similarly, constrain Processed into the following form

[0063]

[0064] Finally, problems (P2)-(P4) are solved iteratively until the problem converges.

[0065] According to the present invention, a transmissive reconfigurable intelligent metasurface-enabled collaborative sensing and spatial alignment system includes: a plurality of transmissive reconfigurable intelligent metasurface transceivers TRIS and a target user device;

[0066] The transmissive reconfigurable intelligent metasurface transceiver TRIS comprises: a plurality of transmission units, a controller and a horn antenna;

[0067] The controller uses a block coordinate descent algorithm to solve the beamforming matrix to generate a control signal, and loads the control signal onto the transmission panel to control the amplitude and phase of the transmission panel;

[0068] Based on the amplitude and phase of the transmission panel, a single-tone carrier signal is transmitted based on the horn antenna to achieve beamforming, and the formed beam is transmitted to the target user equipment;

[0069] The beamforming matrix is ​​optimized under the conditions of response error constraints and power constraints of the TRIS beamforming matrix, so that multiple transmissive reconfigurable smart metasurface transceivers TRIS can achieve precise perception and spatial alignment of the collaborative perception area for the same target user equipment.

[0070] Preferably, the step of loading the control signal onto the transmissive panel to control the amplitude and phase of the transmissive panel comprises:

[0071]

[0072] Among them, A n Indicates amplitude; Indicates phase; x k Indicates a control signal.

[0073] Preferably, the TRIS beamforming matrix power constraint includes:

[0074]

[0075] in,[·] nn Indicates taking the diagonal elements of the matrix, P t Indicates the maximum transmit power of the TRIS element, W k represents the beamforming matrix of the kth TRIS, represents the conjugate transpose of the kth TRIS beamforming matrix, the subscript n represents the element index of TRIS, and the subscript k represents the TRIS transceiver index.

[0076] Preferably, the response error constraint of the beamforming matrix includes:

[0077] The cooperative sensing area CSA is approximated as a plane parallel to the ground and expressed in polar coordinates as

[0078] rcosθ=hR k,m cosθ k,m ,

[0079] Where h is the height of TRIS, R k,m represents the distance between the target and TRIS, (θ k,m , ) represents the angle of the beam center; r represents the polar diameter in polar coordinates;

[0080] For small and distant targets that meet the preset requirements, the beam is approximated as an oblique cylinder with an elliptical base, which is expressed in polar coordinates as:

[0081]

[0082] Among them, (Δθ k,m , ) represents the beam width, θ rot =θ-θ k,m -π / 2 represents the projection of the angle between the beam center and the target on the horizontal plane;

[0083] Combining the above CSA and beam solving, the sensing area is an ellipse, whose major and minor axes are expressed as:

[0084]

[0085] In order to keep the cooperative sensing units consistent, the sensing units are approximated as circles. Then there are

[0086]

[0087] In order to make all sensor units of equal size, the target distance R obtained in the first stage is k,m Sort and use the median (R0,θ0, Δθ0, ) as a reference;

[0088]

[0089] According to the k,m and The beam width is adjusted by the formula, and the size of the sensing unit will remain unchanged;

[0090] Defining the angle vector and The element spacings are Δ1 and Δ2 respectively; the directional amplitude response required for the kth TRIS is expressed as:

[0091]

[0092] where Δθ is Δθ k,m The abbreviation of yes The abbreviation of represents the set of all desired signal directions; takes the direction of the AP into account; sets the beam width of different targets to be the same; sets r ad Reorganize into a matrix in angle index order

[0093] The steering matrix of the kth TRIS is defined as:

[0094]

[0095] Among them, A k represents the steering matrix of the kth TRIS; a l (·) represents the steering vector; θ k,l represents the pitch angle of the kth TRIS with respect to path l, represents the azimuth of the kth TRIS with respect to path l, represents the complex space, N represents the number of elements in TRIS, and L represents the number of paths;

[0096] Then, the directional response of the antenna after beamforming is expressed as:

[0097] r k =(W k ) H A k ,

[0098] Where, the superscript H represents the conjugate transpose, and W k represents the beamforming matrix of the kth TRIS, r k represents the directional response of the antenna after beamforming;

[0099] Finally, to ensure spatial alignment performance, the following response error constraints of the beamforming matrix need to be met:

[0100]

[0101] Where K represents the number of TRIS transceivers, represents the conjugate transpose of the direction response vector received by the kth TRIS, r k represents the direction response vector received by the kth TRIS, represents the directional amplitude response required for the kth TRIS Reorganize into a matrix in the order of angle index, γ th Indicates the threshold of spatial registration error.

[0102] Preferably, the step of optimizing the beamforming matrix under the conditions of error constraints and power constraints of the beamforming matrix so as to enable multiple transmissive reconfigurable intelligent metasurface transceivers TRIS to achieve precise sensing and spatial alignment of collaborative sensing areas for the same target user equipment includes:

[0103] By optimizing the beamforming matrix W k and sensing beam scheduling ρ k , to maximize the minimum echo signal-to-noise ratio, the optimization problem is expressed as

[0104]

[0105] r k =(W k ) H A k .

[0106] Where k represents the TRIS index, W k represents the beamforming matrix of the kth TRIS, ρ k represents the kth TRIS sensing beam scheduling variable, m represents the target index, represents the signal-to-interference-plus-noise ratio of the kth TRIS echo about the mth target;

[0107] Introducing the auxiliary variable t, and relaxing the scheduling variables to continuous variables for ease of processing, the problem (P0) can be written as

[0108]

[0109] r k =(W k ) H A k .

[0110] in, Represents the perceptual scheduling variable ρ k relaxation;

[0111] Decoupling the problem (P1), given the sensing beam scheduling variables and beamforming matrix, the original problem can be written as

[0112]

[0113] Given the beamforming matrix and auxiliary variables, optimize the perceptual beam scheduling variable ρ k , then the problem is written as

[0114] (P3)findρ k ,

[0115]

[0116] Among them, the constraints is non-convex, transform it into the following form

[0117]

[0118] in, z k,m,i represents the channel from the kth TRIS to the mth target and finally to the i-th TRIS, represents the conjugate transpose of the channel from the kth TRIS to the mth target and finally to the i-th TRIS, t represents the auxiliary variable to be solved, represents the relaxed sensing beam scheduling variable of the kth TRIS with respect to target j (j≠m), z k,j,i represents the channel from the kth TRIS to the jth target and finally to the i-th TRIS, represents the conjugate transpose of the channel from the kth TRIS to the jth target and finally to the i-th TRIS, represents the Gaussian white noise variance at the kth TRIS;

[0119] After solving problem (P3), we obtain the beamforming matrix and use the semidefinite programming (SDP) to solve the following problem:

[0120]

[0121] Similarly, constrain Processed into the following form

[0122]

[0123] Finally, problems (P2)-(P4) are solved iteratively until the problem converges.

[0124] Compared with the prior art, the present invention has the following beneficial effects:

[0125] 1. The present invention implements beamforming and sensing beam scheduling through TRIS, and achieves spatial alignment of the collaborative sensing area by adjusting the beam width, significantly improving the collaborative sensing gain of the system;

[0126] 2. The joint optimization algorithm proposed in this paper effectively designs the beamforming matrix and sensing beam scheduling, further improving the system's collaborative sensing performance. Through the block coordinate descent (BCD) algorithm, it achieves high-precision solutions and fast convergence.

[0127] 3. The system architecture proposed in this invention is simple and easy to deploy, with significant advantages in hardware cost and energy efficiency. Compared with traditional antenna array technology, TRIS has lower hardware cost and energy consumption. This combination of high performance and low power consumption makes it an ideal solution for the next generation of green wireless communication systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0128] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0129] Figure 1 Schematic diagram of the collaborative sensing system that powers the transmissive reconfigurable intelligent metasurface transceiver TRIS.

[0130] Figure 2 Schematic diagram of the change of minimum echo signal-to-noise ratio with the number of TRIS elements under different schemes.

[0131] Figure 3 Schematic diagram of the minimum echo signal-to-noise ratio changing with power under different schemes.

[0132] Figure 4 Schematic diagram of the spatial alignment effect of the collaborative area. DETAILED DESCRIPTION

[0133] The present invention will be described in detail below with reference to specific embodiments. The following examples will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those skilled in the art, several changes and improvements can be made without departing from the scope of the present invention. These all fall within the scope of protection of the present invention.

[0134] Example 1

[0135] According to the present invention, a transmissive reconfigurable intelligent metasurface-enabled collaborative sensing and spatial alignment system is provided. Figure 1 As shown, it includes: multiple transmissive reconfigurable intelligent metasurface transceivers TRIS and target user equipment;

[0136] The transmissive reconfigurable intelligent metasurface transceiver TRIS comprises: a plurality of transmission units, a controller and a horn antenna;

[0137] The controller uses a block coordinate descent algorithm to solve the TRIS beamforming matrix of multiple transmissive reconfigurable intelligent metasurface transceivers to generate control signals, and loads the control signals onto the transmissive panel to control the amplitude and phase of the transmissive panel;

[0138] Based on the amplitude and phase of the transmission panel, a single-tone carrier signal is transmitted based on the horn antenna to achieve beamforming, and the formed beam is transmitted to the target user equipment;

[0139] The beamforming matrix and sensing beam scheduling are optimized under the response error constraint and the power constraint of the TRIS beamforming matrix, so that multiple transmissive reconfigurable smart metasurface transceivers TRIS can achieve precise sensing and spatial alignment of the collaborative sensing area for the same target user equipment.

[0140] The present invention utilizes a low-power, low-cost TRIS transceiver to implement beamforming and spatially aligns the cooperation area, thereby improving the performance gain of the network in a cooperative manner.

[0141] Specifically, the controller adopts the block coordinate descent BCD algorithm to solve the beamforming matrix and perception beam scheduling optimization problem of the transmission panel; the controller calculates the beamforming matrix W according to the beamforming matrix k Generate control signal x k , and loaded onto the transmission panel to control the amplitude A of the transmission panel element n and phase A n and yes The parameters in the horn antenna transmits a single-tone carrier signal carrying panel information to realize direct digital modulation, realize beamforming, and reach the target user.

[0142] Specifically, the cooperative sensing system enabled by the transmissive reconfigurable intelligent metasurface transceiver TRIS has K TRIS transceivers and M target users, which solves the spatial alignment problem of the cooperative sensing area. c ×N r elements and arranged in a uniform plane array, then the radar channel received by the i-th TRIS about the k-th TRIS transmission reflected by the m-th target can be expressed as

[0143]

[0144] in represents the complex reflection coefficient, d k,m and d i,m denote the distances between target m and the kth TRIS and the ith TRIS, respectively, and λ c Represents the wavelength of electromagnetic waves, S RCS represents the RCS of the target. The downlink steering vector can be expressed as

[0145]

[0146] Among them, n r =[0,1,…,N r -1] T , n c =[0,1,…,N c -1] T ,(n r ,n c ) represents the element position index of TRIS, and θ k,m They represent the azimuth and elevation angles between the kth TRIS and the mth target, respectively. Since the TRIS transceiver has only one receiving antenna, its receiving channel gain can be expressed as

[0147]

[0148] Among them, d i,m represents the distance between the mth target and the i-th TRIS receiver.

[0149] The signal emitted by TRIS can be expressed as

[0150]

[0151] in, represents the sensing beamforming matrix, TRIS supports multi-stream transmission and separates echo signals through signal processing, so that different targets can be distinguished from each other in terms of distance, angle and speed.k,m ∈{0,1} to represent the link establishment status between the kth TRIS and the mth target. Therefore, after being reflected by the target, the echo signal received by the kth TRIS can be expressed as

[0152]

[0153] in, = represents the Gaussian white noise at TRIS. Then, the signal-to-interference-plus-noise ratio (SINR) of the kth TRIS echo with respect to the mth target can be expressed as follows:

[0154]

[0155] Due to the use of TRIS transceiver, it has different power constraints from traditional multi-antenna, which can be expressed as follows

[0156]

[0157] in,[·] nn Indicates taking the diagonal elements of the matrix, P t Indicates the maximum transmit power of the TRIS element.

[0158] Specifically, in order to spatially align the cooperative sensing area and achieve cooperative sensing gain, a beamforming algorithm with adjustable beam width is adopted.

[0159] The cooperative sensing area (CSA) can be approximated as a plane parallel to the ground and can be expressed in polar coordinates as

[0160] rcosθ=hR k,m cosθ k,m ,

[0161] Among them, r is the polar diameter of the polar coordinate, h is the height of TRIS, R k,m represents the distance between the target and TRIS, (θ k,m , ) represents the angle of the beam center.

[0162] For small and distant targets, the beam can be approximated as an oblique cylinder with an elliptical base, which can be expressed in polar coordinates as

[0163]

[0164] Among them, (Δθ k,m , ) represents the beam width, θ rot =θ-θ k,m -π / 2 represents the projection of the angle between the beam center and the target on the horizontal plane.

[0165] Combining the above CSA and beam solution, it can be obtained that the sensing area is an ellipse with its major axis and short axis It can be expressed as

[0166]

[0167] and

[0168]

[0169] In order to keep the cooperative sensing units consistent, the sensing units are first approximated as circles, i.e. Then there are

[0170]

[0171] Next, in order to make all sensor units of equal size, the target distance R obtained in the first stage is k,m Sort and use the median (R0,θ0, Δθ0, ) for reference.

[0172]

[0173] Then according to the above k,m and The beam width can be adjusted by the formula, and the size of the sensing unit will remain unchanged.

[0174] Spatial alignment of sensing areas by adjusting beamwidth: In collaborative scenarios, adjusting beamwidth is a key technique for spatially aligning sensing areas. By adjusting beamwidth, the range and shape of a single TRIS sensing area can be altered, allowing different TRIS sensing areas to overlap spatially, ultimately improving overall network performance. The following is a method for adjusting beamwidth, including:

[0175] First, define the angle vector:

[0176] and The element spacing is Δ1 and Δ2 respectively. The directional amplitude response required for the kth TRIS can be expressed as

[0177]

[0178] in, represents the set of all desired signal directions, taking the direction of the AP into account. (Δθ, ) represents the expected beam spacing and azimuth width. To simplify the process, the beam widths of different targets are set to be the same. Constant Used to limit the -3dB half-power beamwidth. In subsequent processing, r ad Reorganize into a matrix in angle index order

[0179] Second, the steering matrix of the kth TRIS is defined as

[0180]

[0181] where a l (·) represents the steering vector.

[0182] Then, the directional response of the antenna after beamforming can be expressed as

[0183] r k =(W k ) H A k ,

[0184] Finally, to ensure spatial alignment performance, the following constraints need to be met

[0185]

[0186] Among them, γ th Indicates the threshold of spatial registration error.

[0187] Specifically, it aims to optimize the beamforming matrix W k and sensing beam scheduling ρ k , to maximize the minimum echo signal-to-noise ratio, the optimization problem can be expressed as

[0188]

[0189] r k =(W k ) H A k .

[0190] Introducing the auxiliary variable t, and relaxing the scheduling variables to continuous variables for ease of processing, the problem (P0) can be written as

[0191]

[0192] r k =(W k ) H A k .

[0193] The present invention provides an auxiliary variable design in a TRIS-enabled collaborative sensing system to achieve a maximized minimum signal-to-noise ratio.

[0194] Solve for the auxiliary variables:

[0195] Decoupling the problem (P1), given the sensing beam scheduling variables and beamforming matrix, the original problem can be written as

[0196]

[0197] The present invention provides a sensing beam scheduling design in a TRIS-enabled cooperative sensing system, and ensures signal-to-noise ratio and scheduling variable constraints.

[0198] Solve to get the sensing beam scheduling ρ k :

[0199] Given the beamforming matrix and auxiliary variables, the problem of optimizing the perceptual beam scheduling variables can be written as

[0200] (P3)findρ k ,

[0201]

[0202] The constraints is non-convex, transform it into the following form

[0203]

[0204] in

[0205] The present invention provides a beamforming design in a TRIS-enabled cooperative sensing system to minimize the directional response error of cooperative sensing and meet the constraints of signal-to-noise ratio and TRIS transmission power.

[0206] Solve to get the beamforming W k :

[0207] After solving problem (P3), the beamforming matrix W is obtained k , use semidefinite programming (SDP) to solve the following problem

[0208]

[0209] Similarly, constrain Processed into the following form

[0210]

[0211] Finally, problems (P2)-(P4) are solved iteratively until the problem converges.

[0212] By optimizing the beamforming matrix W k and sensing beam scheduling ρ k, to maximize the minimum echo signal-to-noise ratio, and achieve spatial alignment of the cooperative sensing area by adjusting the beam width, thereby improving the system's cooperative sensing performance.

[0213] Example 2

[0214] Example 2 is a preferred example of Example 1

[0215] According to a cooperative sensing and spatial alignment method enabled by a transmissive reconfigurable intelligent metasurface provided by the present invention, the cooperative sensing and spatial alignment system enabled by the transmissive reconfigurable intelligent metasurface is applied to optimize the beamforming matrix W k and sensing beam scheduling ρ k , to maximize the minimum echo signal-to-noise ratio, and achieve spatial alignment of the cooperative sensing area by adjusting the beam width, thereby improving the system's cooperative sensing performance.

[0216] The collaborative sensing and spatial alignment method enabled by the transmissive reconfigurable intelligent metasurface includes:

[0217] Collaborative sensing area approximation step: by approximating the collaborative sensing area as a rectangle parallel to the xoy plane, the beam is approximated as an oblique cylinder with an elliptical base in the far field;

[0218] Perception beam scheduling steps: Design perception beam scheduling variables and formulate a collaborative perception scheduling plan;

[0219] Beamforming steps: The TRIS panel of the transmissive reconfigurable intelligent metasurface transceiver performs beamforming through a controller to control the amplitude and phase of each transmission unit. At the same time, it controls the beam width through beamforming to achieve spatial alignment of the collaborative sensing area.

[0220] Allocation step: Use the block coordinate descent (BCD) method to solve the joint beamforming and sensing beam scheduling optimization problem, transform the non-convex problem into a convex problem, and perform efficient resource allocation.

[0221] In this embodiment, during signal transmission, multiple TRISs perform joint beamforming design and spatial alignment of collaborative sensing areas to obtain the optimal echo signal-to-noise ratio;

[0222] TRIS optimizes beamforming: Considering the maximum transmission power of each transmission element is P t , then the beamforming matrix W after TRIS beamforming is k Including power distribution design;

[0223] TRIS optimizes sensing beam scheduling: By optimizing sensing beam scheduling variables, a collaborative sensing beam scheduling scheme is formulated.

[0224] This paper presents an optimization scheme for a cooperative sensing system powered by a transmissive reconfigurable intelligent metasurface (TRIS) transceiver: maximizing the minimum echo signal-to-noise ratio (SNR) as the performance metric while limiting total transmit power. By constructing an optimization problem with minimum echo signal-to-noise ratio as the objective function and maximum transmit power and sensing beam scheduling as constraints, the present invention implements a design for a cooperative sensing system powered by a transmissive reconfigurable intelligent metasurface (TRIS) transceiver.

[0225] Design of an optimization scheme in a collaborative sensing system enabled by a transmissive reconfigurable intelligent metasurface (TRIS) transceiver: The TRIS introduced in this optimization problem does not require multiple RF links, complex up-conversion and power distribution modules, and can achieve beamforming in a simple way, while achieving better performance at a lower cost.

[0226] Optimization Design of a Collaborative Sensing System Powered by a Transmissive Reconfigurable Intelligent Metasurface (TRIS): The proposed optimization problem of maximizing the minimum echo signal-to-noise ratio is a non-convex problem, and a global optimal solution is not directly achievable. This paper applies a block coordinate descent algorithm and optimizes all optimization variables to obtain a high-quality suboptimal solution.

[0227] Aiming at the diversified perception needs of next-generation wireless networks, the present invention provides a novel collaborative perception system design enabled by a transmissive reconfigurable intelligent metasurface transceiver (TRIS).

[0228] According to the collaborative sensing system enabled by the transmissive reconfigurable intelligent metasurface transceiver (TRIS) provided by the present invention, a joint design scheme of TRIS beamforming, sensing beam scheduling and collaborative area spatial alignment is provided.

[0229] TRIS requires beamforming design, which is achieved by controlling the phase of each transmission element. Simultaneously, the beam width is controlled to achieve spatial alignment of the collaborative sensing area.

[0230] The present invention particularly provides a novel TRIS-enabled collaborative sensing system and spatial alignment method as well as a minimum echo signal-to-noise ratio maximization solution. Figure 1 Describes the basic structural composition of the invention, Figure 2 、 Figure 3 and Figure 4 The collaborative sensing performance of the invention under different schemes is compared.

[0231] As a cutting-edge technology in the communications field, the Transmissive Reconfigurable Intelligent Metasurface Transceiver (TRIS) demonstrates significant advantages in many areas thanks to its unique signal manipulation and resource integration capabilities. Amidst increasingly limited spectrum resources, TRIS can optimize the spatial distribution of signals, reduce signal interference, and improve spectrum reuse efficiency through flexible beam steering. Furthermore, TRIS utilizes only passive components to manipulate signals, resulting in low power consumption. Furthermore, TRIS can provide strong support for the fusion of multimodal data. In scenarios such as intelligent transportation and the Industrial Internet of Things, the spatial alignment capabilities of TRIS can precisely align communication data, sensor-collected perception data, and computational results in time and space, enabling collaborative data processing and deep fusion, thereby enhancing the system's understanding and response capabilities to complex environments and tasks. Therefore, leveraging TRIS to improve the performance of collaborative sensing systems is highly effective, while also reducing system deployment costs, and possesses significant application value in next-generation wireless networks.

[0232] This paper provides a novel TRIS-enabled collaborative sensing system and spatial alignment method to maximize the minimum echo signal and achieve joint optimization design within this system. The novel system includes multiple TRIS sensors, a controller, a horn antenna, an optimization algorithm, and a target echo signal-to-noise ratio. The core of the optimization algorithm is optimization and block coordinate descent.

[0233] The present invention takes maximizing the minimum echo signal-to-noise ratio of the system as the performance indicator, limits the TRIS transmission power, performs joint beamforming and perception beam scheduling optimization design on multiple TRIS, and combines spatial alignment to improve the collaborative gain of the system.

[0234] The collaborative sensing system, powered by the Transmissive Reconfigurable Intelligent Metasurface (TRIS), eliminates the need for extensive radio frequency links, power distribution networks, and complex signal processing units. This design achieves superior performance at lower cost and power consumption. By combining TRIS beamforming and sensing beam scheduling, the collaborative gain of the present invention is significantly improved.

[0235] Those skilled in the art will appreciate that, in addition to implementing the system, device, and various modules provided by the present invention in purely computer-readable program code, it is entirely possible to implement the same program in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, embedded microcontrollers, and the like by logically programming the method steps. Therefore, the system, device, and various modules provided by the present invention can be considered a hardware component, and the modules included therein for implementing various programs can also be considered structures within the hardware component; the modules for implementing various functions can also be considered both software programs for implementing the method and structures within the hardware component.

[0236] The above describes specific embodiments of the present invention. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. The embodiments of this application and the features in the embodiments may be combined with each other in any manner unless there is a conflict.

Claims

1. A collaborative sensing and spatial alignment method enabled by a transmissive reconfigurable intelligent metasurface, characterized in that: include: Step S1: The controller uses a block coordinate descent algorithm to solve the TRIS beamforming matrix of multiple transmissive reconfigurable intelligent metasurface transceivers to generate control signals, and loads the control signals onto the transmissive panel to control the amplitude and phase of the transmissive panel; Step S2: Based on the amplitude and phase of the transmission panel, a single-tone carrier signal is transmitted via a horn antenna to implement beamforming, and the formed beam is transmitted to the target user equipment; Step S3: Optimizing the beamforming matrix and sensing beam scheduling under the conditions of response error constraints and power constraints of the TRIS beamforming matrix, so that multiple transmissive reconfigurable smart metasurface transceivers TRIS can achieve precise sensing of the same target user equipment and spatial alignment of the collaborative sensing area; The transmissive reconfigurable intelligent metasurface transceiver TRIS includes: a plurality of transmission units, a controller and a horn antenna.

2. The collaborative sensing and spatial alignment method enabled by a transmissive reconfigurable intelligent metasurface according to claim 1, characterized in that: The step S1 comprises: Among them, A n Indicates amplitude; Indicates phase; x k Indicates a control signal.

3. The collaborative sensing and spatial alignment method enabled by a transmissive reconfigurable intelligent metasurface according to claim 1, characterized in that: The power constraints of the TRIS beamforming matrix include: in,[·] nn Indicates taking the diagonal elements of the matrix, P t Indicates the maximum transmit power of the TRIS element, W k represents the beamforming matrix of the kth TRIS, represents the conjugate transpose of the kth TRIS beamforming matrix, the subscript n represents the element index of TRIS, and the subscript k represents the TRIS transceiver index.

4. The collaborative sensing and spatial alignment method enabled by a transmissive reconfigurable intelligent metasurface according to claim 1, characterized in that: The response error constraints of the beamforming matrix include: The cooperative sensing area CSA is approximated as a plane parallel to the ground and expressed in polar coordinates as rcosθ=h-R k,m cosθ k,m , Where h is the height of TRIS, R k,m Indicates the distance between the target and TRIS, represents the angle of the beam center; r represents the polar diameter in polar coordinates; For small and distant targets that meet the preset requirements, the beam is approximated as an oblique cylinder with an elliptical base, which is expressed in polar coordinates as: in, represents the beam width, θ rot =θ-θ k,m -π / 2 represents the projection of the angle between the beam center and the target on the horizontal plane; Combining the above CSA and beam solving, the sensing area is an ellipse, whose major and minor axes are expressed as: In order to keep the cooperative sensing units consistent, the sensing units are approximated as circles. Then there are In order to make all sensor units of equal size, the target distance R obtained in the first stage is k,m Sort and use the median For reference; According to the k,m and The beam width is adjusted by the formula, and the size of the sensing unit will remain unchanged; Defining the angle vector and The element spacings are Δ1 and Δ2 respectively; the directional amplitude response required for the kth TRIS is expressed as: where Δθ is Δθ k,m The abbreviation of yes The abbreviation of represents the set of all desired signal directions; takes the direction of the AP into account; sets the beam width of different targets to be the same; sets r ad Reorganize into a matrix in angle index order The steering matrix of the kth TRIS is defined as: Among them, A k represents the steering matrix of the kth TRIS; a l (·) represents the steering vector; θ k,l represents the pitch angle of the kth TRIS with respect to path l, represents the azimuth of the kth TRIS with respect to path l, represents the complex space, N represents the number of elements in TRIS, and L represents the number of paths; Then, the directional response of the antenna after beamforming is expressed as: r k =(W k ) H A k , Where, the superscript H represents the conjugate transpose, and W k represents the beamforming matrix of the kth TRIS, r k represents the directional response of the antenna after beamforming; Finally, to ensure spatial alignment performance, the following response error constraints of the beamforming matrix need to be met: Where K represents the number of TRIS transceivers, represents the conjugate transpose of the direction response vector received by the kth TRIS, r k represents the direction response vector received by the kth TRIS, represents the directional amplitude response required for the kth TRIS Reorganize into a matrix in the order of angle index, γ th Indicates the threshold of spatial registration error.

5. The collaborative sensing and spatial alignment method enabled by a transmissive reconfigurable intelligent metasurface according to claim 1, characterized in that: The step S3 comprises: By optimizing the beamforming matrix W k and sensing beam scheduling ρ k , to maximize the minimum echo signal-to-noise ratio, the optimization problem is expressed as r k =(W k ) H A k . Where k represents the TRIS index, W k represents the beamforming matrix of the kth TRIS, ρ k represents the kth TRIS sensing beam scheduling variable, m represents the target index, represents the signal-to-interference-plus-noise ratio of the kth TRIS echo about the mth target; Introducing the auxiliary variable t, and relaxing the scheduling variables to continuous variables for ease of processing, the problem (P0) can be written as r k =(W k ) H A k . in, Represents the perceptual scheduling variable ρ k relaxation; Decoupling the problem (P1), given the sensing beam scheduling variables and beamforming matrix, the original problem can be written as Given the beamforming matrix and auxiliary variables, optimize the perceptual beam scheduling variable ρ k , then the problem is written as (P3) findρ k , Among them, the constraints is non-convex, transform it into the following form in, z k,m,i represents the channel from the kth TRIS to the mth target and finally to the i-th TRIS, represents the conjugate transpose of the channel from the kth TRIS to the mth target and finally to the i-th TRIS, t represents the auxiliary variable to be solved, represents the relaxed sensing beam scheduling variable of the kth TRIS with respect to target j (j≠m), z k,j,i represents the channel from the kth TRIS to the jth target and finally to the i-th TRIS, represents the conjugate transpose of the channel from the kth TRIS to the jth target and finally to the i-th TRIS, represents the Gaussian white noise variance at the kth TRIS; After solving problem (P3), we obtain the beamforming matrix and use the semidefinite programming (SDP) to solve the following problem: Similarly, constrain Processed into the following form Finally, problems (P2)-(P4) are solved iteratively until the problem converges.

6. A collaborative sensing and spatial alignment system enabled by a transmissive reconfigurable intelligent metasurface, characterized in that: include: Multiple transmissive reconfigurable smart metasurface transceivers TRIS and target user equipment; The transmissive reconfigurable intelligent metasurface transceiver TRIS comprises: a plurality of transmission units, a controller and a horn antenna; The controller uses a block coordinate descent algorithm to solve the beamforming matrix to generate a control signal, and loads the control signal onto the transmission panel to control the amplitude and phase of the transmission panel; Based on the amplitude and phase of the transmission panel, a single-tone carrier signal is transmitted based on the horn antenna to achieve beamforming, and the formed beam is transmitted to the target user equipment; The beamforming matrix is ​​optimized under the conditions of response error constraints and power constraints of the TRIS beamforming matrix, so that multiple transmissive reconfigurable smart metasurface transceivers TRIS can achieve precise perception and spatial alignment of the collaborative perception area for the same target user equipment.

7. The collaborative sensing and spatial alignment system enabled by a transmissive reconfigurable intelligent metasurface according to claim 6, characterized in that: The step of loading the control signal onto the transmissive panel to control the amplitude and phase of the transmissive panel includes: Among them, A n Indicates amplitude; Indicates phase; x k Indicates a control signal.

8. The collaborative sensing and spatial alignment system enabled by a transmissive reconfigurable intelligent metasurface according to claim 6, characterized in that: The power constraints of the TRIS beamforming matrix include: in,[·] nn Indicates taking the diagonal elements of the matrix, P t Indicates the maximum transmit power of the TRIS element, W k represents the beamforming matrix of the kth TRIS, represents the conjugate transpose of the kth TRIS beamforming matrix, the subscript n represents the element index of TRIS, and the subscript k represents the TRIS transceiver index.

9. The collaborative sensing and spatial alignment system enabled by a transmissive reconfigurable intelligent metasurface according to claim 6, characterized in that: The response error constraints of the beamforming matrix include: The cooperative sensing area CSA is approximated as a plane parallel to the ground and expressed in polar coordinates as rcosθ=h-R k,m cosθ k,m , Where h is the height of TRIS, R k,m Indicates the distance between the target and TRIS, represents the angle of the beam center; r represents the polar diameter in polar coordinates; For small and distant targets that meet the preset requirements, the beam is approximated as an oblique cylinder with an elliptical base, which is expressed in polar coordinates as: in, represents the beam width, θ rot =θ-θ k,m -π / 2 represents the projection of the angle between the beam center and the target on the horizontal plane; Combining the above CSA and beam solving, the sensing area is an ellipse, whose major and minor axes are expressed as: In order to keep the cooperative sensing units consistent, the sensing units are approximated as circles. Then there are In order to make all sensor units of equal size, the target distance R obtained in the first stage is k,m Sort and use the median For reference; According to the k,m and The beam width is adjusted by the formula, and the size of the sensing unit will remain unchanged; Defining the angle vector and The element spacings are Δ1 and Δ2 respectively; the directional amplitude response required for the kth TRIS is expressed as: where Δθ is Δθ k,m The abbreviation of yes The abbreviation of represents the set of all desired signal directions; takes the direction of the AP into account; sets the beam width of different targets to be the same; sets r ad Reorganize into a matrix in angle index order The steering matrix of the kth TRIS is defined as: Among them, A k represents the steering matrix of the kth TRIS; a l (·) represents the steering vector; θ k,l represents the pitch angle of the kth TRIS with respect to path l, represents the azimuth of the kth TRIS with respect to path l, represents the complex space, N represents the number of elements in TRIS, and L represents the number of paths; Then, the directional response of the antenna after beamforming is expressed as: r k =(W k ) H A k , Where, the superscript H represents the conjugate transpose, and W k represents the beamforming matrix of the kth TRIS, r k represents the directional response of the antenna after beamforming; Finally, to ensure spatial alignment performance, the following response error constraints of the beamforming matrix need to be met: Where K represents the number of TRIS transceivers, represents the conjugate transpose of the direction response vector received by the kth TRIS, r k represents the direction response vector received by the kth TRIS, represents the directional amplitude response required for the kth TRIS Reorganize into a matrix in the order of angle index, γ th Indicates the threshold of spatial registration error.

10. The collaborative sensing and spatial alignment system enabled by a transmissive reconfigurable intelligent metasurface according to claim 6, characterized in that: The method optimizes the beamforming matrix under the conditions of error constraints and power constraints of the beamforming matrix so that multiple transmissive reconfigurable intelligent metasurface transceivers TRIS achieve precise perception and spatial alignment of collaborative perception areas for the same target user equipment, including: By optimizing the beamforming matrix W k and sensing beam scheduling ρ k , to maximize the minimum echo signal-to-noise ratio, the optimization problem is expressed as r k =(W k ) H A k . Where k represents the TRIS index, W k represents the beamforming matrix of the kth TRIS, ρ k represents the kth TRIS sensing beam scheduling variable, m represents the target index, represents the signal-to-interference-plus-noise ratio of the kth TRIS echo about the mth target; Introducing the auxiliary variable t, and relaxing the scheduling variables to continuous variables for ease of processing, the problem (P0) can be written as r k =(W k ) H A k . in, Represents the perceptual scheduling variable ρ k relaxation; Decoupling the problem (P1), given the sensing beam scheduling variables and beamforming matrix, the original problem can be written as Given the beamforming matrix and auxiliary variables, optimize the perceptual beam scheduling variable ρ k , then the problem is written as (P3) findρ k , Among them, the constraints is non-convex, transform it into the following form in, z k,m,i represents the channel from the kth TRIS to the mth target and finally to the i-th TRIS, represents the conjugate transpose of the channel from the kth TRIS to the mth target and finally to the i-th TRIS, t represents the auxiliary variable to be solved, represents the relaxed sensing beam scheduling variable of the kth TRIS with respect to target j (j≠m), z k,j,i represents the channel from the kth TRIS to the jth target and finally to the i-th TRIS, represents the conjugate transpose of the channel from the kth TRIS to the jth target and finally to the i-th TRIS, represents the Gaussian white noise variance at the kth TRIS; After solving problem (P3), we obtain the beamforming matrix and use the semidefinite programming (SDP) to solve the following problem: Similarly, constrain Processed into the following form Finally, problems (P2)-(P4) are solved iteratively until the problem converges.

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