Method and system for realizing high-order signal safety communication based on phase-controlled metasurface

Abstract

The invention discloses a method and a system for realizing high-order signal security communication based on a phase-controlled metasurface, and relates to the technical field of electric power security communication, comprising the following steps of: based on a phase-controlled metasurface communication transmitter architecture, forming a preset high-order signal in a far field by performing space-time coding on a metasurface unit; a signal constellation diagram in an expected direction only generates expansion with equal-proportion amplitude, and a signal in an unexpected direction generates distortion of different degrees according to the change of a space-time coding pattern. Based on the phase control metasurface, high-order signal modulation is directly realized through space coding, and the confidentiality of a signal physical layer is improved through time domain coding.

Description

Technical Field

[0001] The present invention relates to the field of electric power safety communication technology, and in particular to a method and system for realizing high-order signal safety communication based on phased-control metasurface. Background Art

[0002] Existing communication transmitter systems based on phase-controlled metasurfaces can directly modulate baseband data information onto the carrier signal irradiated on the metasurface by controlling the metasurface reflection coefficient or transmission coefficient. The signal reflected or transmitted by the metasurface is the traditional RF signal that has completed amplitude and phase modulation. Work published in related fields in recent years has shown that it is very difficult to design a metasurface unit that can independently and accurately control the amplitude and phase of the incident wave due to the limitation of the coupling of amplitude and phase control. Although some published work has achieved independent control of amplitude and phase, its control range and accuracy are not ideal, and it is not easy to be directly used for the modulation of high-order signals. It is relatively easier to design a digitally coded metasurface whose reflection coefficient or transmission coefficient is only phase-adjustable.

[0003] Based on a 2-bit phase-controlled metasurface, Zhang.L et al. proposed a space-time coding scheme in the literature [1] and built a multi-channel direct information transmission system. By optimizing the spatial pattern of the metasurface array and encoding each unit in a periodic sequence, the scheme can independently transmit information to users in different preset spatial directions in different frequency bands, while the signal in the undesired direction will be distorted, which has a certain degree of confidentiality. First, since the scheme introduces a time dimension algorithm, each time a code symbol is transmitted, the metasurface unit needs to be periodically regulated multiple times, which greatly reduces the modulation efficiency of the electronic control device and wastes the control performance of the device; secondly, the signal transmitted to the user is an OOK signal, the spectrum utilization rate is not high, and the communication rate is low; finally, the signal beam width in the desired direction is large, and when the eavesdropper is in certain specific directions or close to the desired direction, it is still possible to eavesdrop on the signal. In the communication transmitter architecture based on the metasurface, improving the spectrum utilization of the modulated signal and the modulation efficiency of the electronic control element in the metasurface unit is the key to achieving high-speed communication. In secure communication, increasing the distortion of the signal in the undesired direction is the key to improving confidentiality. Summary of the invention

[0004] The present invention is proposed in view of the problems existing in the existing high-order signal secure communication and systems based on phased metasurfaces.

[0005] Therefore, the problem to be solved by the present invention is that the security is poor and the communication rate is low, which wastes the control performance of the device.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a method for realizing high-order signal secure communication based on a phased metasurface, which comprises the following steps:

[0008] Construct a metasurface subarray consisting of L×L 2-bit phased-control units arranged periodically;

[0009] Set a random sequence S, and combine each N rows of hypersurface units as a basic set to form X subsets, and all subsets form a subset space A;

[0010] By traversing all the permutations and combinations of the phase control states between subsets in the subset space A, M spatial coding patterns can be obtained, and a mapping relationship table P1 between the spatial coding patterns obtained by all subsets in the subset space A and the preset M-order signal symbols is established;

[0011] Each N columns of hypersurface units are combined into Y subsets as the basic set, and all subsets form a subset space B;

[0012] By traversing all the permutations and combinations of the phase control states between subsets in the subset space B, M spatial coding patterns can be obtained, and a mapping relationship table P2 between the spatial coding patterns obtained by all subsets in the subset space B and the preset M-order signal symbols is established;

[0013] The symbols of the information codeword sequence are sent repeatedly until the transmission is complete.

[0014] As a preferred solution of the method for realizing high-order signal secure communication based on phased metasurface of the present invention, the order of the pre-synthesized QAM signal is M, where M is greater than 8 and is a power of 2, and the relationship between L and M is expressed as:

[0015]

[0016] in, represents a round-up operation, and the metasurface array is composed of N×N metasurface sub-arrays mentioned above, where the value range of N is any positive integer.

[0017] As a preferred solution of the method for realizing high-order signal secure communication based on phased metasurface described in the present invention, wherein: the random sequence S has a length of l and contains the numbers 0 and 1 at the same time, and l is any integer greater than 1.

[0018] As a preferred solution of the method for realizing high-order signal secure communication based on phased metasurface described in the present invention, wherein: the subset space A contains all subsets composed of the basic set, and the combination method is:

[0019] When log 2 When M is an even number, any division of 2 k-1 unpartitioned basic set to the kth subset A kInside,

[0020] When log 2 When M is an odd number, the first and second subsets are divided into one undivided basic set, dividing 3×2 k-3 unpartitioned basic set to the kth subset A k Inside.

[0021] As a preferred solution of the method for realizing high-order signal secure communication based on phased metasurface described in the present invention, the subset space B includes all subsets composed of the basic set, and the combination method is:

[0022] When log 2 When M is an even number, sub-step 6.1: arbitrarily divide 2 k-1 unpartitioned basic set into the kth subset Bk,

[0023] When log 2 When M is an odd number, the first and second subsets are divided into one undivided basic set, dividing 3×2 k-3 unpartitioned basic set into the kth subset Bk.

[0024] As a preferred solution of the method for realizing high-order signal secure communication based on phased metasurface described in the present invention, when sending the symbol of the information codeword sequence, the information codeword sequence to be sent is I and the length is Q. When the length of the random sequence S is less than I, the random sequence S is periodically extended to obtain a sequence S1. The length of the sequence S1 is W, and W cannot be less than the length of the information codeword sequence I. WQ consecutive elements are deleted from the sequence S1.

[0025] Align the information codeword sequence and the 0 and 1 elements in the random sequence S1;

[0026] Initialize t to 1, indicating the tth code element;

[0027] When the element in the random sequence S1 corresponding to the tth information symbol to be transmitted is 0, the first-level step is executed;

[0028] When the element in the random sequence S1 corresponding to the tth information symbol to be transmitted is 1, the secondary step is executed;

[0029] t=t+1, repeat this step until all the symbols of the information codeword sequence are sent.

[0030] As a preferred solution of the method for realizing high-order signal secure communication based on phased metasurface described in the present invention, the first-level step is: according to the code element symbol to be transmitted, by looking up the mapping relationship table P1, adjusting the phase control state of the metasurface unit can synthesize the preset code element symbol in the far field of the metasurface normal;

[0031] The secondary step is: according to the code element symbol to be transmitted, by looking up the mapping relationship table P2, the phase control state of the metasurface unit is adjusted to synthesize the preset code element symbol in the far field of the metasurface normal.

[0032] In a second aspect, an embodiment of the present invention provides a high-order signal secure communication system based on a phased metasurface, which includes a metasurface construction module, a coding pattern generation module, a random sequence processing module, and an information symbol transmission control module;

[0033] The metasurface construction module constructs a metasurface subarray consisting of L×L 2-bit phased units and a metasurface array consisting of N×N metasurface subarrays;

[0034] The coding pattern generation module traverses the subsets in the subset spaces A and B, generates a spatial coding pattern, and establishes a mapping relationship table between the spatial coding pattern and the M-order signal symbol;

[0035] The random sequence processing module is used for generating and periodically extending the random sequence S;

[0036] The information codeword transmission control module is used to control the symbol transmission of the information codeword sequence.

[0037] In a third aspect, an embodiment of the present invention provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, wherein: when the processor executes the computer program, it implements any step of the above-mentioned method for realizing high-order signal secure communication based on phased metasurface.

[0038] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein: when the computer program is executed by a processor, any step of the above-mentioned method for realizing high-order signal secure communication based on phased metasurface is implemented.

[0039] The beneficial effects of the present invention are:

[0040] 1. The method provided by the present invention is applicable to both reflective and transmissive metasurfaces, and is universally applicable to metasurface communication transmitter systems with 2-bit phase control capabilities.

[0041] 2. The high-order signal synthesis method proposed in the present invention does not require periodic time domain coding. For each code symbol transmitted, it is only necessary to adjust a number of electronically controlled components of each unit at most once, thereby achieving efficient utilization of the unit electronically controlled components and improving spectrum utilization.

[0042] 3. The high-order signal synthesis method proposed in the present invention has the characteristics of directional modulation technology. A random sequence S is introduced. In different code element periods, the same code element symbol may correspond to different spatial coding patterns. The orthogonality of the demodulatable directions of signal beams generated by different spatial coding patterns in space is utilized to reduce the demodulatable beam range of the signal in continuous time. The receiver only keeps the error vector magnitude (EVM) value in the expected communication direction to the minimum at all times. While maximizing the signal quality in the expected direction, the signal that deviates from the expected communication direction can be effectively scrambled or hidden.

[0043] 4. This method uses the characteristic that the metasurface can adjust the phase of the incident signal without changing the signal amplitude. Through spatial coding, the high-order signal is synthesized in the far field area of ​​the metasurface. Through time coding, the spatial direction of the correctly demodulated signal is changed to ensure that the signal can be continuously and distortion-free demodulated only in the intersection direction of the demodulated direction. Each change in the spatial pattern of the metasurface array transmits a corresponding high-order symbol, realizing the efficient use of the control performance of the metasurface electric control element and improving the spectrum utilization. This method has the same confidentiality characteristics as traditional directional modulation. An eavesdropper may still be able to eavesdrop on the signal in certain specific directions or near the desired communication direction. However, this scheme introduces a random sequence S and dynamically changes the spatial distribution of the beam, so that the eavesdropper cannot continuously eavesdrop on the signal and can only eavesdrop on part of the signal in certain specific directions, thereby improving the confidentiality of the communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0045] Figure 1 Structural diagram of a method for achieving high-order signal secure communication based on phased metasurfaces.

[0046] Figure 2 Schematic diagram of a 3×3 metasurface array that implements a high-order signal secure communication method based on phased metasurface.

[0047] Figure 3The metasurface array spatial coding pattern corresponding to different code element symbols in the subset space A for realizing a high-order signal secure communication method based on phased metasurface.

[0048] Figure 4 The metasurface array spatial coding pattern corresponding to different code element symbols in the subset space B for realizing a high-order signal secure communication method based on phased metasurface.

[0049] Figure 5 The signal constellation diagram synthesized in the far field in a preset direction for realizing a high-order signal secure communication method based on phased metasurface.

[0050] Figure 6 A signal constellation diagram synthesized by spatial coding patterns of different subsets deviating from the desired direction to realize high-order signal security communication method based on phased metasurface.

[0051] Figure 7 This is a simulation diagram of the distortion distribution of the EVM of the synthetic signal constellation points of different subsets of spatial coding patterns deviating from the desired direction to achieve high-order signal security communication method based on phased metasurface.

[0052] Figure 8 This is a diagram of the changes in the spatial coding patterns corresponding to the 16 code symbols in time sequence for a high-order signal security communication method based on phased metasurface. DETAILED DESCRIPTION

[0053] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0054] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0055] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0056] The present invention is described in detail with reference to schematic diagrams. When describing the embodiments of the present invention, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0057] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0058] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] Example 1

[0060] Reference Figures 1 to 8 , which is the first embodiment of the present invention, provides a method for realizing high-order signal secure communication based on phased metasurface, comprising the following steps:

[0061] S1. Construct a metasurface subarray consisting of L×L 2-bit phased-control units arranged periodically.

[0062] The order of the pre-synthesized QAM signal is M, where M is greater than 8 and is a power of 2. The relationship between L and M is expressed as,

[0063]

[0064] in, represents a round-up operation, and the metasurface array is composed of N×N metasurface sub-arrays mentioned above, where the value range of N is any positive integer.

[0065] S2. Set a random sequence S, and use every N rows of hypersurface units as the basic set to combine into X subsets, and all subsets form a subset space A.

[0066] The random sequence S has a length of l and contains both the numbers 0 and 1, where l is any integer greater than 1.

[0067] In the embodiment, a random sequence S={0,1,1,1,0,1,0,0,1,0} of length 10 is generated.

[0068] S3. By traversing all the permutations and combinations of phase control states between subsets in subset space A, M spatial coding patterns can be obtained, and a mapping relationship table P1 between the spatial coding patterns obtained by all subsets in subset space A and preset M-order signal symbols is established.

[0069] The subset space A contains all subsets composed of the basic set, and the combination method is:

[0070] When log 2 When M is an even number, any division of 2 k-1 unpartitioned basic set to the kth subset A k Inside,

[0071]

[0072] When log 2 When M is an odd number, the first and second subsets are divided into one undivided basic set, dividing 3×2 k-3 unpartitioned basic set to the kth subset A k Inside.

[0073] In the embodiment, each row of hypersurface units is combined into two subsets as a basic set, and all subsets form a subset space A, because log 2 M=4 is an even number, and the first basic set (the first row of hypersurface units) is divided into the first subset A1, and the remaining two undivided basic sets (the second and third rows of hypersurface units) are divided into the second subset A2.

[0074] In a symbol period, all 2-bit phase-independent controllable units in each subset in the subset space A always maintain the same phase control state. A combination of phase control states between subsets is called a spatial coding pattern. By traversing all the permutations and combinations of phase control states between subsets in the subset space A, 16 spatial coding patterns can be obtained, such as Figure 3 shown.

[0075] Table 1: Mapping relationship between the spatial coding patterns obtained by establishing all subsets in the subset space A and the preset 16-order signal symbols

[0076]

[0077]

[0078] S4. Take every N columns of hypersurface units as the basic set to form Y subsets, and all subsets form a subset space B.

[0079] Each column of hypersurface units is combined into two subsets as the basic set, and all subsets form the subset space B. Because log 2 M=4 is an even number, and the first basic set (the first column of hypersurface units) is divided into the first subset B1, and the remaining two undivided basic sets (the second and third columns of hypersurface units) are divided into the second subset B2.

[0080] S5. By traversing all the permutations and combinations of phase control states between subsets in subset space B, M spatial coding patterns can be obtained, and a mapping relationship table P2 between the spatial coding patterns obtained by all subsets in subset space B and preset M-order signal symbols is established.

[0081] The subset space B contains all subsets of the basic set, and the combination method is,

[0082] When log 2 When M is an even number, sub-step 6.1: arbitrarily divide 2 k-1 unpartitioned basic set into the kth subset Bk,

[0083] When log 2 When M is an odd number, the first and second subsets are divided into one undivided basic set, dividing 3×2 k-3 unpartitioned basic set into the kth subset Bk.

[0084] In a symbol period, all 2-bit phase-independent controllable units in each subset in the subset space B always maintain the same phase control state. A combination of phase control states between subsets is called a spatial coding pattern. By traversing all the permutations and combinations of phase control states between subsets in the subset space B, 16 spatial coding patterns can be obtained, such as Figure 4 shown.

[0085] Table 2: Mapping relationship between the spatial coding patterns obtained by establishing all subsets in the subset space B and the preset 16-order signal symbols

[0086]

[0087] S6. Repeat sending the symbols of the information codeword sequence until the sending is completed.

[0088] When sending the symbol of the information symbol sequence, the information symbol sequence to be sent is I, and the length is Q. When the length of the random sequence S is less than I, the random sequence S is periodically extended to obtain a sequence S1. The length of the sequence S1 is W, and W cannot be less than the length of the information symbol sequence I. WQ consecutive elements are deleted from the sequence S1.

[0089] Align the information codeword sequence and the 0 and 1 elements in the random sequence S1;

[0090] Initialize t to 1, indicating the tth code element;

[0091] When the element in the random sequence S1 corresponding to the tth information symbol to be transmitted is 0, the first-level step is executed;

[0092] When the element in the random sequence S1 corresponding to the tth information symbol to be transmitted is 1, the secondary step is executed;

[0093] t=t+1, repeat this step until all the symbols of the information codeword sequence are sent.

[0094] The first-level step is: according to the code element symbol to be transmitted, by looking up the mapping relationship table P1, the phase control state of the metasurface unit is adjusted to synthesize the preset code element symbol in the far field of the metasurface normal;

[0095] The secondary step is: according to the code element symbol to be transmitted, by looking up the mapping relationship table P2, the phase control state of the metasurface unit is adjusted to synthesize the preset code element symbol in the far field of the metasurface normal.

[0096] In the embodiment, the information codeword sequence to be sent is I={0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15}, and the length of the random sequence S is 10, which is smaller than the information codeword sequence I. Therefore, the random sequence S is periodically extended once, and the four elements at the end are deleted to obtain the sequence S1={0,1,1,1,0,1,0,0,1,0,0,1,1,1,0,1}; the information codeword symbols and the 0 and 1 elements in the random sequence S1 are aligned, and the corresponding relationship is shown in Table 3; let t=1.

[0097] Table 3: Correspondence table

[0098] t 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Random sequence S1 0 1 1 1 0 1 0 0 1 0 0 1 1 1 0 1 Codeword sequence I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

[0099] When the first information codeword is sent, the element corresponding to the random sequence S1 is 0, and the codeword symbol to be transmitted is 0. By looking up the mapping relationship table 1 and adjusting the phase state of the metasurface unit, the preset codeword symbol is synthesized in the preset direction.

[0100] Let t = t + 1, the spatial coding pattern corresponding to all 10 code symbols to be transmitted is as follows: Figure 7 shown.

[0101] Based on the communication transmitter system of the metasurface with 2-bit phase control capability, a preset 16-order QAM signal can be synthesized in the normal direction of the far-field array; the signal constellation diagram synthesized at different times deviating from the normal direction is as follows: Figure 6As shown in the figure, the EVM distortion distribution simulation diagram of the synthesized signal in different directions at different times is as follows Figure 7 As shown, in the embodiment, the spatial coding pattern corresponding to all 16 code elements to be sent in time sequence changes as shown in FIG. Figure 8 shown.

[0102] In summary, this method uses the characteristic of the metasurface that the phase of the incident signal can be adjusted without changing the signal amplitude. Through spatial coding, a high-order signal is synthesized in the far field of the metasurface. Through time coding, the spatial direction of the correctly demodulated signal is changed to ensure that the signal can be continuously and distortion-free demodulated only in the intersection direction of the demodulated directions. Each change in the spatial pattern of the metasurface array transmits a corresponding high-order symbol, realizing the efficient use of the control performance of the metasurface electric control element and improving the spectrum utilization. This method has the same confidentiality characteristics as traditional directional modulation. An eavesdropper may still be able to eavesdrop on the signal in certain specific directions or near the desired communication direction. However, this scheme introduces a random sequence S and dynamically changes the spatial distribution of the beam, so that the eavesdropper cannot continuously eavesdrop on the signal and can only eavesdrop on part of the signal in certain specific directions, thereby improving the confidentiality of the communication.

[0103] Example 2

[0104] On the basis of the first embodiment, this embodiment further provides a high-order signal security communication system based on a phased metasurface, including a metasurface construction module, a coding pattern generation module, a random sequence processing module, and an information symbol transmission control module;

[0105] The metasurface construction module constructs a metasurface subarray consisting of L×L 2-bit phased units and a metasurface array consisting of N×N metasurface subarrays;

[0106] The coding pattern generation module traverses the subsets in the subset spaces A and B, generates a spatial coding pattern, and establishes a mapping relationship table between the spatial coding pattern and the M-order signal symbol;

[0107] The random sequence processing module is used for generating and periodically extending the random sequence S;

[0108] The information codeword transmission control module is used to control the symbol transmission of the information codeword sequence.

[0109] This embodiment also provides a computer device, which is suitable for implementing a high-order signal security communication method based on a phased metasurface, including a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute computer-executable instructions to implement the high-order signal security communication method based on a phased metasurface as proposed in the above embodiment.

[0110] The computer device may be a terminal, and the computer device includes a processor, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0111] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, a method for realizing high-order signal secure communication based on phased metasurface as proposed in the above embodiment is implemented.

[0112] The storage medium proposed in this embodiment and the data storage method proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be found in the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0113] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the present invention.

Claims

1. A method for realizing high-order signal secure communication based on phased metasurface, characterized in that: The following steps are included: Construct a metasurface subarray consisting of L×L 2-bit phased-control units arranged periodically; Set a random sequence S, and combine each N rows of hypersurface units as a basic set to form X subsets, and all subsets form a subset space A; By traversing all the permutations and combinations of the phase control states between subsets in the subset space A, M spatial coding patterns can be obtained, and a mapping relationship table P1 between the spatial coding patterns obtained by all subsets in the subset space A and the preset M-order signal symbols is established; Each N columns of hypersurface units are combined into Y subsets as the basic set, and all subsets form a subset space B; By traversing all the permutations and combinations of the phase control states between subsets in the subset space B, M spatial coding patterns can be obtained, and a mapping relationship table P2 between the spatial coding patterns obtained by all subsets in the subset space B and the preset M-order signal symbols is established; The symbols of the information codeword sequence are sent repeatedly until the transmission is complete.

2. The method for realizing high-order signal secure communication based on phased metasurface according to claim 1, characterized in that: The order of the pre-synthesized QAM signal is M, where M is greater than 8 and is a power of 2. The relationship between L and M is expressed as, in, represents a round-up operation, and the metasurface array is composed of N×N metasurface sub-arrays mentioned above, where the value range of N is any positive integer.

3. The method for realizing high-order signal secure communication based on phased metasurface according to claim 2, characterized in that: The random sequence S has a length of l and contains both the numbers 0 and 1, where l is any integer greater than 1.

4. The method for realizing high-order signal secure communication based on phased metasurface according to claim 3, characterized in that: The subset space A contains all subsets composed of the basic set, and the combination method is: When log2M is even, any division of 2 k-1 unpartitioned basic set to the kth subset A k Inside, When log2M is an odd number, the first and second subsets are divided into one undivided basic set, dividing 3×2 k-3 unpartitioned basic set to the kth subset A k Inside.

5. The method for realizing high-order signal secure communication based on phased metasurface according to claim 4, characterized in that: The subset space B contains all subsets of the basic set, and the combination method is, When log2M is even, Substep 6.1: Arbitrary division of 2 k-1 unpartitioned basic set into the kth subset Bk, When log2M is an odd number, the first and second subsets are divided into one undivided basic set, dividing 3×2 k-3 unpartitioned basic set into the kth subset Bk.

6. The method for realizing high-order signal secure communication based on phased metasurface according to claim 5, characterized in that: When sending the symbol of the information symbol sequence, the information symbol sequence to be sent is I, and the length is Q. When the length of the random sequence S is less than I, the random sequence S is periodically extended to obtain a sequence S1. The length of the sequence S1 is W, and W cannot be less than the length of the information symbol sequence I. WQ consecutive elements are deleted from the sequence S1. Align the information codeword sequence and the 0 and 1 elements in the random sequence S1; Initialize t to 1, indicating the tth code element; When the element in the random sequence S1 corresponding to the tth information symbol to be transmitted is 0, the first-level step is executed; When the element in the random sequence S1 corresponding to the tth information symbol to be transmitted is 1, the secondary step is executed; t=t+1, repeat this step until all the symbols of the information codeword sequence are sent.

7. The method for realizing high-order signal secure communication based on phased metasurface according to claim 6, characterized in that: The first-level step is: according to the code element symbol to be transmitted, by looking up the mapping relationship table P1, the phase control state of the metasurface unit is adjusted to synthesize the preset code element symbol in the far field of the metasurface normal; The secondary step is: according to the code element symbol to be transmitted, by looking up the mapping relationship table P2, the phase control state of the metasurface unit is adjusted to synthesize the preset code element symbol in the far field of the metasurface normal.

8. A system for realizing high-order signal secure communication based on phased metasurface, based on the method for realizing high-order signal secure communication based on phased metasurface according to any one of claims 1 to 7, characterized in that: It includes a metasurface construction module, a coding pattern generation module, a random sequence processing module, and an information symbol transmission control module; The metasurface construction module constructs a metasurface subarray consisting of L×L 2-bit phased units and a metasurface array consisting of N×N metasurface subarrays; The coding pattern generation module traverses the subsets in the subset spaces A and B, generates a spatial coding pattern, and establishes a mapping relationship table between the spatial coding pattern and the M-order signal symbol; The random sequence processing module is used for generating and periodically extending the random sequence S; The information symbol transmission control module is used to control the symbol transmission of the information symbol sequence.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method for realizing high-order signal secure communication based on phased metasurface described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for realizing high-order signal secure communication based on phased metasurface described in any one of claims 1 to 7 are implemented.

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