Arbitrary beam forming method and device of information metamaterial

Abstract

The invention discloses an arbitrary beam forming method of an information metamaterial, and relates to the technical field of wireless communication and artificial electromagnetic new materials. According to the method, a beam forming model of the information metamaterial is established, a plurality of single beams in any direction are generated through a phase compensation method, customized design of beam width and beam number is realized based on a segmentation principle and a superposition principle, and a beam forming loss function is converged to a minimum value through iterative optimization; and finally, an optimization result is loaded to a phase coding configuration device of the information metamaterial, and arbitrary beam forming of the information metamaterial is realized. The invention further discloses an arbitrary beam forming device of the information metamaterial, beam forming of the information metamaterial with the beam pointing, the beam number, the beam width and the beam gain capable of being flexibly customized is supported, and the arbitrary beam forming device of the information metamaterial is deployed on information metamaterial hardware and has the advantages of being high in flexibility and universality.

Description

Technical Field

[0001] The present invention relates to the technical field of wireless communication and artificial electromagnetic new materials, and in particular to an arbitrary beam synthesis method and device for information metamaterials. Background Art

[0002] Information metamaterials refer to a class of artificial electromagnetic materials that are carefully designed to achieve unique electromagnetic properties rarely seen in nature and to establish a connection between information space and electromagnetic space. As a two-dimensional form of information metamaterials, smart metasurfaces have received extensive attention and research in the field of wireless communications due to their low cost, low power consumption, and conformal design. By regulating the phase of the reflected signal of the electromagnetic unit, the smart metasurface can actively regulate the various characteristics of the wireless channel, achieve coverage enhancement and performance doubling of the communication system, and is a potential enabling technology for the next generation of mobile communication systems.

[0003] Beamforming technology is one of the key technologies in the field of intelligent metasurface-assisted wireless communication. By regulating the reflection phase coding of each component unit, the intelligent metasurface can intelligently focus the reflected beam to one or more directions to achieve the effect of beamforming. Traditional beamforming technology based on intelligent metasurfaces usually uses phase compensation or holographic methods to achieve phase alignment of signals reflected by multiple electromagnetic units at the receiving end. Specifically, in the far field area, a phase coding configuration intelligent metasurface with a uniform phase gradient distribution can be used to achieve signal phase alignment at the receiving end; in the near field area, the phase coding configuration required to compensate for the optical path difference can be obtained by measuring the distance between the electromagnetic unit and the transceiver. However, one of the bottlenecks in realizing intelligent metasurface beamforming at present is that it is impossible to flexibly control the beam pointing, number of beams, beam width and beam gain of the reflected beam, which is usually limited to signal enhancement or suppression in a limited number of directions or locations. At the same time, the characteristic of intelligent metasurfaces that only the reflection phase is adjustable has also become the key to the increased difficulty of this problem. Therefore, how to achieve flexible regulation of the reflected beam of the intelligent metasurface is one of the key issues in the field of intelligent metasurface-assisted wireless communication. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a method and device for arbitrary beam synthesis of information metamaterials. The present invention supports flexible customization of information metamaterial beam synthesis in terms of beam pointing, number of beams, beam width and beam gain, and is deployed on information metamaterial hardware, with the characteristics of high flexibility and strong versatility.

[0005] The present invention adopts the following technical solutions to solve the above technical problems:

[0006] An arbitrary beam synthesis method of an information metamaterial proposed in the present invention comprises:

[0007] Establish a beamforming model for information metamaterials;

[0008] According to the beamforming model, a single beam with arbitrary direction is generated through phase compensation method;

[0009] The beam width of a single beam is controlled based on the segmentation principle, and multiple beams with adjustable widths are reflected simultaneously based on the superposition principle.

[0010] Design the arbitrary beam synthesis loss function of the information metamaterial, iteratively optimize the directivity patterns of multiple beams with adjustable widths, so that the arbitrary beam synthesis loss function converges to the minimum value, thereby obtaining the arbitrary beam synthesis phase encoding;

[0011] The arbitrary beam synthesis phase coding is loaded into the phase coding configuration device of the information metamaterial to realize the arbitrary beam synthesis of the information metamaterial.

[0012] As a further optimization scheme of the arbitrary beam synthesis method of an information metamaterial described in the present invention, a beam synthesis model of an information metamaterial is established, including:

[0013] A three-dimensional rectangular coordinate system is established with the information metamaterial as the origin, the position coordinates of the transmitting antenna are fixed, and the position area to which the beam to be synthesized belongs is determined. The receiving antenna grid points that describe the potential position of the receiving antenna are uniformly sampled within the determined position area. The power distribution of the radio waves emitted by the transmitting antenna at the receiving antenna grid points after being reflected by the information metamaterial is analyzed, and a beam synthesis model of the information metamaterial is established.

[0014] As a further optimization scheme of the arbitrary beam synthesis method of an information metamaterial described in the present invention, a single beam with an arbitrary direction is generated by a phase compensation method according to a beam synthesis model; comprising:

[0015] Based on the established beam synthesis model of information metamaterials, the distance between each electromagnetic unit in the information metamaterial and the transmitting antenna, as well as the distance between each electromagnetic unit in the information metamaterial and the receiving antenna are calculated; the two distances are summed, and the phase that should be compensated for each electromagnetic unit is obtained based on the working frequency band and the wavelength of the radio wave; the phase is compensated by configuring the reflection phase of each electromagnetic unit in the information metamaterial, thereby generating a single beam with an arbitrarily directed direction.

[0016] As a further optimization scheme of the arbitrary beam synthesis method of the information metamaterial described in the present invention, the beam width of a single beam is regulated based on the segmentation principle, including:

[0017] Based on the segmentation principle, the area to be covered is determined in the receiving antenna grid points according to the preset width of a single beam, and the area to be covered and the information meta-structure material are simultaneously divided into multiple sub-blocks, so that each sub-block of the information meta-structure material corresponds one-to-one to each sub-block of the area to be covered; according to the beam synthesis model and the method of generating a single beam with any direction through a phase compensation method, each sub-block of the information meta-structure material generates a beam pointing to the corresponding sub-block of the area to be covered, so that the reflected beam of the entire information meta-structure material covers the entire area to be covered.

[0018] As a further optimization scheme of the arbitrary beam synthesis method of an information metamaterial described in the present invention, a plurality of beams with adjustable widths are reflected simultaneously based on the superposition principle; comprising:

[0019] Based on the superposition principle, given multiple groups of beam phase configurations whose beam widths have been adjusted according to the segmentation principle, the given multiple groups of beam phase configurations are converted into corresponding reflection coefficients. These reflection coefficients are directly superimposed and normalized to achieve simultaneous reflection of multiple beams with adjustable widths.

[0020] As a further optimization scheme of the arbitrary beam synthesis method of the information metamaterial described in the present invention,

[0021] The arbitrary beam synthesis loss function of the information metamaterial is designed, and the directivity patterns of multiple beams with adjustable widths are iteratively optimized so that the arbitrary beam synthesis loss function converges to the minimum value, thereby obtaining the arbitrary beam synthesis phase encoding; the details are as follows:

[0022] According to the preset beam pointing, beam number, beam width and beam gain parameters of the information metamaterial reflection beam, combined with the established beam synthesis model of the information metamaterial, an arbitrary beam synthesis loss function of the information metamaterial is defined;

[0023] Taking multiple beams of adjustable width that are realized and reflected simultaneously after regulation based on the segmentation principle and the superposition principle as the initial values ​​of the optimization variables, according to the arbitrary beam synthesis loss function, an iterative search optimization algorithm is used to make the arbitrary beam synthesis loss function converge to the minimum value, and the arbitrary beam synthesis phase encoding is obtained.

[0024] As a further optimization scheme of the arbitrary beam synthesis method of an information metamaterial described in the present invention, the arbitrary beam synthesis phase coding is loaded into the phase coding configuration device of the information metamaterial to realize the arbitrary beam synthesis of the information metamaterial; the details are as follows:

[0025] The arbitrary beam synthesis phase code is loaded into a phase coding configuration device of an information metastructure material, and the phase coding configuration device includes an information metastructure material, a control circuit module matched with the information metastructure material, a signal transmission cable and a host computer. The host computer transmits the arbitrary beam synthesis phase code to the information metastructure material through the control circuit module to configure the reflection phase shift of each electromagnetic unit of the information metastructure material to realize the arbitrary beam synthesis of the information metastructure material.

[0026] As a further optimization scheme of the arbitrary beam synthesis method of an information metamaterial described in the present invention, according to the superposition principle, the reflection coefficients of multiple beams are superimposed to synthesize the required beam pattern, and the phase of the beam pattern is designed as follows:

[0027]

[0028] in, represents the phase of the i-th electromagnetic unit used to generate the s-th beam in the information metamaterial, a s represents the weight of the sth beam, S is the number of beams, is an imaginary unit, is the phase of the i-th intelligent metasurface electromagnetic unit in the information metamaterial after superposition, and e is the natural base.

[0029] As a further optimization scheme of the arbitrary beam synthesis method of the information metamaterial described in the present invention, the arbitrary beam synthesis loss function J total (Θ) is:

[0030] J total (Θ)=λ1J1(Θ)+λ2J2(Θ)

[0031] Among them, J1(Θ) is used to measure the difference between the generated beam and the ideal beam, J2(Θ) is an additional constraint, λ1 and λ2 are the corresponding weight coefficients of J1(Θ) and J2(Θ), respectively;

[0032]

[0033] Where w is the weight vector, the superscript T indicates transposition, and A RX is the array response matrix determined by the receiver position, Θ is the information metamaterial reflection coefficient matrix, a TX is the array response vector determined by the transmitter position, and the superscript H represents the conjugate transpose;

[0034]

[0035] Among them, the constraint Used to control the power ratio of the beam, limit the matrix Each row of represents a constraint, and there are L constraints in total. It is a real matrix space with L rows and S columns; represents the received signal power of S main lobes, is an S-dimensional real vector space, and the constraint Used to suppress power fluctuations within the sth beam, Represents the received signal power of all receiving points in the sth beam.

[0036] An arbitrary beam synthesis device for information metamaterials, comprising:

[0037] A beamforming model generation module is used to establish a beamforming model for information metamaterials;

[0038] A single beam forming module is used to generate a single beam with any direction by a phase compensation method according to a beam forming model;

[0039] The beam control module is used to control the beam width of a single beam based on the segmentation principle, and then realize the simultaneous reflection of multiple beams with adjustable widths based on the superposition principle;

[0040] Arbitrary beam phase coding module, used to design the arbitrary beam synthesis loss function of information metamaterials, iteratively optimize the directivity patterns of multiple beams with adjustable widths, so that the arbitrary beam synthesis loss function converges to the minimum value, thereby obtaining arbitrary beam synthesis phase coding;

[0041] The beam synthesis module is used to load arbitrary beam synthesis phase coding into the phase coding configuration device of the information meta-material to realize arbitrary beam synthesis of the information meta-material.

[0042] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:

[0043] (1) Compared with the traditional information metamaterial beam synthesis technology, the present invention comprehensively utilizes the segmentation principle, superposition principle and iterative optimization technology to support information metamaterial beam synthesis in which the beam pointing, number of beams, beam width and beam gain can be flexibly customized, and is deployed on the information metamaterial hardware, with the characteristics of high flexibility and strong versatility.

[0044] (2) Specifically, the traditional phase compensation technology can only adjust the direction of the reflected beam, while the application of the segmentation principle can adjust the beam width of any single reflected beam, the application of the superposition principle can adjust the number of reflected beams and the beam gain, and the application of iterative optimization technology can minimize the loss function representing the beam synthesis effect, which is beneficial to further enhance the beam synthesis effect based on information metamaterials. By loading the optimization results into the information metamaterial phase encoding configuration device and deploying the configured information metamaterial in the pattern measurement device, the proposed technical solution is fully verified, which is beneficial to the implementation of the technical solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 A flow chart of the arbitrary beam synthesis method of the information metamaterial disclosed in the present invention;

[0046] Figure 2 A schematic diagram of a beam synthesis mathematical model of an information metamaterial established in one embodiment of the present invention;

[0047] Figure 3 A schematic diagram of a phase encoding configuration device for information metamaterials in one embodiment of the present invention;

[0048] Figure 4 It is a schematic diagram of a device for measuring a reflected beam pattern of an information metamaterial in one embodiment of the present invention;

[0049] Figure 5 A simulation result provided in one embodiment of the present invention;

[0050] Figure 6 The following is an actual test result provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0052] like Figure 1 As shown, the arbitrary beam synthesis method and device of the information metamaterial disclosed in the present invention establishes a beam synthesis mathematical model of the information metamaterial, generates a single beam with an arbitrary direction through a phase compensation method, and then realizes the regulation of the beam width and the number of beams based on the segmentation principle and the superposition principle respectively, and converges the beam synthesis loss function to the minimum value through iterative optimization. Finally, the arbitrary beam synthesis phase code is loaded into the information metamaterial phase coding configuration device to realize the arbitrary beam synthesis of the information metamaterial. The method specifically includes the following steps:

[0053] Step S1: Establishing a beamforming model of information metamaterials;

[0054] In the first step of this embodiment, a three-dimensional rectangular coordinate system is established with the information meta-material as the origin, the position coordinates of the transmitting antenna are fixed, and the position area to which the beam to be synthesized belongs is determined. The grid points describing the potential position of the receiving antenna are uniformly sampled in the determined area. By analyzing the power distribution of the radio waves emitted by the transmitting antenna at the grid points of the receiving antenna after being reflected by the information meta-material, a mathematical model of beam synthesis of the information meta-material is established.

[0055] like Figure 2As shown in FIG. 1 , a reflective smart metasurface with M rows and N columns is placed on the xoy plane, and its center is established as the origin. The element of the mth row and nth column of the smart metasurface is represented by E i , where i = (m-1)M + n. x and d y The transmitter (TX) is fixed on the positive half of the z-axis and emits electromagnetic waves vertically to the smart metasurface. The distance from TX to the center of the smart metasurface is d t The receiver (RX) is located along a radius of d r Arc scanning, where the pitch angle and azimuth angle from RX to the center of the smart metasurface are represented by θ r and Both TX and RX are aligned with the center of the smart metasurface. In order to simplify the simulation and measurement, in this embodiment, only the beamforming problem in the xoz plane is considered, that is,

[0056] Ignoring the direct link between TX and RX, the received signal y can be expressed as:

[0057]

[0058] The transmission signal is assumed to be a single-tone signal, that is, x = 1, n represents Gaussian noise, and obeys distributed. represents the reflection coefficient matrix, given by where β i ∈[0,2π] represents E i The reflection phase. and denote the array response vectors from TX to the smart metasurface and from the smart metasurface to RX, respectively, which are related to the positions of TX and RX, and are v t =[x t ,y t ,z t ] T and v r =[x r ,y r ,z r ] T . Their detailed definitions are:

[0059]

[0060] where α t,i and α r,i Represents TX and E respectively i Between sub-links and E i Large-scale fading factor of the sub-link to RX.t,i =‖v i -v t ‖, r r,i =‖v i -v r ‖, where v i =[x i ,y i ,z i ] T Indicates E i The position of the signal. λ represents the wavelength of the signal. α t,i and α r,i It can be expressed as Among them, G t and G r Denote the gains of the transmitting antenna and the receiving antenna respectively. F(θ) represents the radiation pattern of the electromagnetic unit of the smart metasurface, which can be modeled as F(θ) = cosθ, where θ t,i and θ r,i Respectively from TX and RX to E i The pitch angle.

[0061] Along Figure 2 The K possible positions of RX are uniformly sampled, and the kth position is represented by v r,k Use these points to depict the expected beam pattern. The position of TX is fixed at v t .

[0062] definition Then the received signal at K sampling points can be expressed as:

[0063]

[0064] in and After that, the expected value of the received power That is, the beam pattern, which can be derived as:

[0065]

[0066] Therefore, the average signal-to-noise ratio (SNR) of RX at the kth position is given by:

[0067]

[0068] Step S2: Generate a single beam with an arbitrary direction by a phase compensation method according to the beamforming model;

[0069] In the second step of this embodiment, based on the beam synthesis mathematical model of the information metamaterial established in step S1, the distance between each electromagnetic unit in the information metamaterial and the transmitting antenna and the distance between each electromagnetic unit in the information metamaterial and the transmitting antenna are calculated; the two are summed, and the phase that should be compensated for each electromagnetic unit is obtained by referring to the system operating frequency band and the wavelength of the radio wave. Based on this, the reflection phase of each electromagnetic unit of the information metamaterial is configured to generate a single beam with any direction.

[0070] Specifically, first determine the receiver position v r and the transmitter position v t , and calculate the pointing angle of the target beam and its propagation distance in space. i The reflected phase is dynamically adjusted to ensure that the beam points in the direction of the receiver and achieves maximum gain.

[0071] The phase compensation design is based on the principle of beam synthesis. For each electromagnetic unit E of the smart metasurface i , its reflection phase compensation value is based on the spatial position v of the receiver r and the spatial position v of the transmitter t The purpose of phase compensation is to ensure that the signal reflected from the smart metasurface to the receiver achieves the best gain in the target direction, thereby optimizing the communication effect.

[0072] In this embodiment, the calculation formula of the phase compensation is:

[0073]

[0074] Among them, r t,i Represents the electromagnetic unit E from the transmitter to the smart metasurface i The distance, r r,i Represents the electromagnetic unit E from the smart metasurface i The distance to the receiver, λ represents the wavelength of the signal.

[0075] Step S3: adjusting the beam width of a single beam based on the segmentation principle, and then realizing simultaneous reflection of multiple beams with adjustable widths based on the superposition principle;

[0076] In the third step of this embodiment, the beam width control of a single reflected beam of the information metamaterial is firstly implemented based on the segmentation principle, and then the simultaneous reflection of multiple beams with adjustable widths is implemented based on the superposition principle.

[0077] First, according to the segmentation principle, several position points are uniformly sampled in the required coverage area to obtain v r,1 ,...,v r,N, where N is the number of columns of the smart metasurface. Then, the nth column is assigned to a single beam code based on the position v of the receiver. r,n Phase compensation design is performed, that is Where n = (i-1) mod N + 1. In this way, the generated beam will cover the entire target area, thereby achieving precise control of the beam width.

[0078] On this basis, according to the superposition principle, the required beam pattern is synthesized by superimposing the reflection coefficients of multiple wide beams. Specifically, by weighted superposition of the reflection phases of each wide beam, the phase design of any specified beam pattern can be obtained. The superimposed phase design can be expressed as:

[0079]

[0080] in, represents the phase design of the i-th smart metasurface unit generating the s-th wide beam, a s represents the weight of the sth beam, By adjusting the weight vector a, the power allocation ratio of the generated beam can be controlled, thereby adjusting the power of the synthesized beam.

[0081] Through the coordinated application of the segmentation principle and the superposition principle, the number, width, and power ratio of the generated beams can be flexibly customized to generate any desired beam pattern. In addition, this method has low computational complexity and can efficiently synthesize the target beam pattern. However, although this method shows good performance when generating simple beam patterns, significant inter-beam interference (IBI) may occur when synthesizing complex beam patterns. Therefore, further optimization is necessary to improve the synthesis effect of complex beam patterns.

[0082] Step S4: designing an arbitrary beam synthesis loss function of the information metamaterial, and iteratively optimizing the directivity patterns of multiple beams with adjustable widths so that the arbitrary beam synthesis loss function converges to a minimum value, thereby obtaining arbitrary beam synthesis phase encoding;

[0083] In the fourth step of this embodiment, based on the preset beam pointing, beam number, beam width and beam gain parameters of the information metamaterial reflection beam, combined with the beam synthesis mathematical model of the information metamaterial given in step S1, the loss function of arbitrary beam synthesis is defined. The result of the algorithm execution in step S3 is used as the initial value of the optimization variable, and according to the specific form of the defined loss function, an appropriate iterative optimization algorithm is proposed, and the beam synthesis loss function is converged to the minimum value through iterative optimization.

[0084] Specifically, the loss function can be designed to include a combination of multiple metrics, such as the number of beams, beam pointing, beam width, main lobe gain, side lobe suppression, etc. Considering the characteristics of information metamaterials, the loss function can be expressed as:

[0085] J total (Θ)=λ1J1(Θ)+λ2J2(Θ)

[0086] Among them, J1(Θ) is used to measure the difference between the generated beam and the ideal beam, especially focusing on the accuracy and directivity of the main lobe. It can be achieved by maximizing the main lobe gain and minimizing the side lobe power. For example, let the weight vector be expressed as Then J1(Θ) can be defined as

[0087]

[0088] The additional constraint J2(Θ) can be defined as

[0089]

[0090] Among them, the constraint Used to control the power ratio of the beam. Constraint matrix Each row of represents a constraint, and there are L constraints in total. represents the received signal power of the S main lobes. In addition, the constraint It is used to suppress the power fluctuation in the sth beam, thereby generating a flat-top wide beam. Here, Represents the received signal power of all receiving points in the sth beam.

[0091] After the loss function is designed, an iterative optimization algorithm is used to minimize the loss function. Specific optimization methods may include gradient descent, genetic algorithm, particle swarm algorithm, etc. The iterative optimization algorithm proposed in this embodiment of the algorithm is given below:

[0092] Input: RIS related parameters: M, N, λ, d x ,d y ; Transmitter and receiver positions v t ,v r ; Weight w; Population size N pop ; Optimization step size N step ; Maximum number of iterations N max

[0093] Output: Optimal phase shift encoding matrix Θ

[0094] 1. Use the method in step S3 and quantize to get the initial solution Θ init

[0095] 2. Initialize Θ0 to Θinit , and by randomly switching Θ init 10N step phase encoding to initialize the other Θ p (p=1,2,...,N pop -1)

[0096] 3. Initialization 0→N iter , I MN →Θ opt

[0097] 4.repeat

[0098] 5. Randomly switch each Θ p 3N step The unit phase is encoded to generate

[0099] 6.

[0100] 7.

[0101] 8.end if

[0102] 9. Calculate the selection probability of each individual: And randomly select N according to the roulette principle pop Individual Θ q (q=1,2,...,N pop -1)

[0103] 10. Randomly switch each Θ q N step Unit phase encoding is obtained

[0104] 11.

[0105] 12.

[0106] 13.end if

[0107] 14. If Θ p If there is no change for a long time, randomly switch Θ init 10N step Phase code to obtain the new θ p

[0108] 15. N iter +1→N iter

[0109] 16. Adaptive adjustment of N step To promote convergence

[0110] 17. until N iter =N max

[0111] The algorithm uses the phase encoding of the electromagnetic unit of the smart metasurface given in step S3 as the optimization initial value, and through quantization and repeated iterations to update the reflection coefficient matrix Θ, the loss function gradually converges, and finally obtains a beam synthesis result that meets the requirements. Through this optimization process, beams of arbitrary shapes can be effectively synthesized, while overcoming the beam shape limitations of traditional methods and achieving higher beam synthesis performance.

[0112] Step S5: loading the arbitrary beam synthesis phase code into the information metamaterial phase coding configuration device to realize the arbitrary beam synthesis of the information metamaterial;

[0113] In step S5 of the present embodiment, first, the optimization result obtained in step S4 is loaded into the information metamaterial phase encoding configuration device, which is composed of an information metamaterial (such as an intelligent metasurface), a matching control circuit module, a signal transmission cable, and a host computer. The configuration software in the host computer transmits the optimization result to the information metamaterial; secondly, the configured information metamaterial is deployed in a directional pattern measurement device, and the transmitting antenna is fixed at the position determined in step S2 to measure and verify the beamforming method disclosed in the present invention.

[0114] The beam synthesis method of information metamaterials is deployed on information metamaterials hardware. Information metamaterials beam synthesis supports customized beam pointing, number of beams, beam width and beam gain.

[0115] In this embodiment, the information metamaterial phase encoding configuration device is as follows: Figure 3 As shown in the figure, the specific configuration steps are as follows: First, start the local server software, and the server will call the packet capture software to monitor the network traffic in real time. Then, log in to the server homepage from the browser, correctly configure the serial port number and device ID in the web page configuration bar and submit. Next, query and connect to the smart metasurface through the web page interface. Finally, upload the pre-prepared smart metasurface phase encoding file, and the local server will configure the phase encoding for each electromagnetic unit of the smart metasurface through the serial port.

[0116] The directional pattern measuring device used in this embodiment is as follows Figure 4As shown, this embodiment uses a beam pattern measurement system to measure and verify the beam synthesis method. The prepared smart metasurface consists of 60×60 units, and 1-bit phase control is achieved by switching PIN diodes, which is mainly used for testing. Other parameters in the measurement are consistent with those in the simulation. The smart metasurface is placed on the central platform of the turntable, the transmitting antenna is placed on the telescopic arm of the turntable, and the receiving antenna is fixed to the outside of the turntable. The main lobe of the antenna is aligned with the center of the smart metasurface. During the measurement, the turntable platform and the telescopic arm can rotate simultaneously. Taking the rotating smart metasurface as the reference point, the incident direction is kept constant. At the same time, the receiving antenna moves along an arc trajectory centered on the smart metasurface. The USRP-2974 transmits a single-tone detection signal, which is up-converted to 35GHz by a millimeter-wave converter and radiated into space. After wireless propagation, reflection, and down-conversion processing, the signal is finally received for analysis. In addition, sufficient absorbing materials are placed in the environment to suppress the generation of multipath effects.

[0117] In this embodiment, in order to verify the ability of the present invention to synthesize arbitrary beam patterns, the following beam synthesis task is proposed: generate three beams, one of which is a narrow beam for directional coverage, one wide beam for regional coverage (whose half-power beamwidth is 15°), and one low-power beam for close-range directional coverage (whose power is 6dB lower than other beams). 60°, 30°, and -45° are randomly selected as the desired directions of the three beams. After implementing steps S1 to S4, the optimal phase encoding for configuring the smart metasurface is obtained and deployed on the smart metasurface sample according to step S5.

[0118] Figure 5 and Figure 6 The simulation and measurement results of the beamforming task proposed in this embodiment are given respectively. Among them, the simulation and measurement results show excellent consistency. The measured beams show the above three functions: directional coverage - achieved by a narrow beam pointing to 60°; regional coverage - achieved by a wide beam pointing to 30°, and its half-power beamwidth is about 15°; close-range directional coverage, achieved by a low-power beam pointing to -45°. These beams provide information metamaterials with the ability to cover irregular areas. At the same time, the present invention has been verified to be able to generate phase encoding suitable for direct deployment on smart metasurface hardware.

[0119] An arbitrary beam synthesis device for information metamaterials, comprising:

[0120] A beamforming model generation module is used to establish a beamforming model for information metamaterials;

[0121] A single beam forming module is used to generate a single beam with any direction by a phase compensation method according to a beam forming model;

[0122] The beam control module is used to control the beam width of a single beam based on the segmentation principle, and then realize the simultaneous reflection of multiple beams with adjustable widths based on the superposition principle;

[0123] Arbitrary beam phase coding module, used to design the arbitrary beam synthesis loss function of information metamaterials, iteratively optimize the directivity patterns of multiple beams with adjustable widths, so that the arbitrary beam synthesis loss function converges to the minimum value, thereby obtaining arbitrary beam synthesis phase coding;

[0124] The beam synthesis module is used to load arbitrary beam synthesis phase coding into the phase coding configuration device of the information meta-material to realize arbitrary beam synthesis of the information meta-material.

[0125] An embodiment of the present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and capable of running on the processor, wherein when the processor executes the computer program, the steps of the arbitrary beam synthesis method of information metamaterials as described in the first aspect or any corresponding embodiment thereof are implemented.

[0126] An embodiment of the present invention also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the steps of the arbitrary beam synthesis method of information metamaterials as described in the first aspect or any corresponding embodiment thereof.

[0127] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes. The schemes in the embodiments of the present invention may be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0128] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0129] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0130] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0131] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0132] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. An arbitrary beam synthesis method for information metamaterials, characterized in that: include: Establish a beamforming model for information metamaterials; According to the beamforming model, a single beam with arbitrary direction is generated through phase compensation method; The beam width of a single beam is controlled based on the segmentation principle, and multiple beams with adjustable widths are reflected simultaneously based on the superposition principle. Design the arbitrary beam synthesis loss function of the information metamaterial, iteratively optimize the directivity patterns of multiple beams with adjustable widths, so that the arbitrary beam synthesis loss function converges to the minimum value, thereby obtaining the arbitrary beam synthesis phase encoding; The arbitrary beam synthesis phase coding is loaded into the phase coding configuration device of the information metamaterial to realize the arbitrary beam synthesis of the information metamaterial.

2. The arbitrary beam synthesis method of information metamaterial according to claim 1, characterized in that: Establish a beamforming model for information metamaterials, including: A three-dimensional rectangular coordinate system is established with the information metamaterial as the origin, the position coordinates of the transmitting antenna are fixed, and the position area to which the beam to be synthesized belongs is determined. The receiving antenna grid points that describe the potential position of the receiving antenna are uniformly sampled within the determined position area. The power distribution of the radio waves emitted by the transmitting antenna at the receiving antenna grid points after being reflected by the information metamaterial is analyzed, and a beam synthesis model of the information metamaterial is established.

3. The arbitrary beam synthesis method of information metamaterial according to claim 1, characterized in that: According to the beamforming model, a single beam with any direction is generated by phase compensation method; including: Based on the established beam synthesis model of information metamaterials, the distance between each electromagnetic unit in the information metamaterial and the transmitting antenna, as well as the distance between each electromagnetic unit in the information metamaterial and the receiving antenna are calculated; the two distances are summed, and the phase that should be compensated for each electromagnetic unit is obtained based on the working frequency band and the wavelength of the radio wave; the phase is compensated by configuring the reflection phase of each electromagnetic unit in the information metamaterial, thereby generating a single beam with an arbitrarily directed direction.

4. The arbitrary beam synthesis method of information metamaterial according to claim 2, characterized in that: The beam width of a single beam is controlled based on the segmentation principle, including: Based on the segmentation principle, the area to be covered is determined in the receiving antenna grid points according to the preset width of a single beam, and the area to be covered and the information meta-structure material are simultaneously divided into multiple sub-blocks, so that each sub-block of the information meta-structure material corresponds one-to-one to each sub-block of the area to be covered; according to the beam synthesis model and the method of generating a single beam with any direction through a phase compensation method, each sub-block of the information meta-structure material generates a beam pointing to the corresponding sub-block of the area to be covered, so that the reflected beam of the entire information meta-structure material covers the entire area to be covered.

5. The arbitrary beam synthesis method of information metamaterial according to claim 1, characterized in that: Based on the superposition principle, multiple beams with adjustable widths are reflected simultaneously; including: Based on the superposition principle, given multiple groups of beam phase configurations whose beam widths have been adjusted according to the segmentation principle, the given multiple groups of beam phase configurations are converted into corresponding reflection coefficients. These reflection coefficients are directly superimposed and normalized to achieve simultaneous reflection of multiple beams with adjustable widths.

6. The arbitrary beam synthesis method of information metamaterial according to claim 1, characterized in that: The arbitrary beam synthesis loss function of the information metamaterial is designed, and the directivity patterns of multiple beams with adjustable widths are iteratively optimized so that the arbitrary beam synthesis loss function converges to the minimum value, thereby obtaining the arbitrary beam synthesis phase encoding; the details are as follows: According to the preset beam pointing, beam number, beam width and beam gain parameters of the information metamaterial reflection beam, combined with the established beam synthesis model of the information metamaterial, an arbitrary beam synthesis loss function of the information metamaterial is defined; Taking multiple beams of adjustable width that are realized and reflected simultaneously after regulation based on the segmentation principle and the superposition principle as the initial values ​​of the optimization variables, according to the arbitrary beam synthesis loss function, an iterative search optimization algorithm is used to make the arbitrary beam synthesis loss function converge to the minimum value, and the arbitrary beam synthesis phase encoding is obtained.

7. The arbitrary beam synthesis method of information metamaterial according to claim 1, characterized in that: The arbitrary beam synthesis phase coding is loaded into the phase coding configuration device of the information meta-material to realize the arbitrary beam synthesis of the information meta-material; the details are as follows: The arbitrary beam synthesis phase code is loaded into a phase coding configuration device of an information metastructure material, and the phase coding configuration device includes an information metastructure material, a control circuit module matched with the information metastructure material, a signal transmission cable and a host computer. The host computer transmits the arbitrary beam synthesis phase code to the information metastructure material through the control circuit module to configure the reflection phase shift of each electromagnetic unit of the information metastructure material to realize the arbitrary beam synthesis of the information metastructure material.

8. The arbitrary beam synthesis method of information metamaterial according to claim 1, characterized in that: According to the superposition principle, the reflection coefficients of multiple beams are superimposed to synthesize the required beam pattern. The phase of the beam pattern is designed as follows: in, represents the phase of the i-th electromagnetic unit used to generate the s-th beam in the information metamaterial, a s represents the weight of the sth beam, S is the number of beams, J is the imaginary unit, is the phase of the i-th intelligent metasurface electromagnetic unit in the information metamaterial after superposition, and e is the natural base.

9. The arbitrary beam synthesis method of information metamaterial according to claim 1, characterized in that: Arbitrary beamforming loss function J total (Θ) is: J total (Θ)=λ1J1(Θ)+λ2J2(Θ) Among them, J1(Θ) is used to measure the difference between the generated beam and the ideal beam, J2(Θ) is an additional constraint, λ1 and λ2 are the corresponding weight coefficients of J1(Θ) and J2(Θ), respectively; Where w is the weight vector, the superscript T indicates transposition, and A RX is the array response matrix determined by the receiver position, Θ is the information metamaterial reflection coefficient matrix, a TX is the array response vector determined by the transmitter position, and the superscript H represents the conjugate transpose; Among them, the constraint Used to control the power ratio of the beam, limit the matrix Each row of represents a constraint, and there are L constraints in total. It is a real matrix space with L rows and S columns; represents the received signal power of S main lobes, is an S-dimensional real vector space, and the constraint Used to suppress power fluctuations within the sth beam, Represents the received signal power of all receiving points in the sth beam.

10. An arbitrary beam synthesis device for information metamaterials, characterized in that: include: A beamforming model generation module is used to establish a beamforming model for information metamaterials; A single beam forming module is used to generate a single beam with any direction by a phase compensation method according to a beam forming model; The beam control module is used to control the beam width of a single beam based on the segmentation principle, and then realize the simultaneous reflection of multiple beams with adjustable widths based on the superposition principle; Arbitrary beam phase coding module, used to design the arbitrary beam synthesis loss function of information metamaterials, iteratively optimize the directivity patterns of multiple beams with adjustable widths, so that the arbitrary beam synthesis loss function converges to the minimum value, thereby obtaining arbitrary beam synthesis phase coding; The beam synthesis module is used to load arbitrary beam synthesis phase coding into the phase coding configuration device of the information meta-material to realize arbitrary beam synthesis of the information meta-material.

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