Switch-assisted RIS circuit and method for optimizing energy benefit of MISO system

Abstract

The invention relates to a switch-assisted RIS circuit and a method for optimizing the energy benefit of an MISO system, and the method comprises the steps: improving an active RIS circuit, adding a switch for a phase shift circuit of each reflection unit, and assisting the MISO system through employing the improved active RIS circuit; calculating the signal to interference ratio of each user in the improved active RIS circuit auxiliary MISO system, the base station sending power and the active RIS sending power, and calculating the total energy consumption of the MISO system based on the base station sending power and the active RIS sending power; an energy benefit optimization objective function of the MISO system is constructed based on the signal to interference ratio of each user and the total energy consumption of the MISO system, an energy benefit optimization scheme of the MISO system is solved based on the objective function, and the switch-assisted RIS circuit is used for implementing the method. Compared with the prior art, the energy of the MISO system is optimized by using the switch-assisted RIS, the power consumption can be reduced by closing an unnecessary RIS branch, and the energy efficiency of the system is improved.

Description

Technical Field

[0001] The present invention relates to the field of communications, and in particular to a switch-assisted RIS circuit and a method for optimizing the energy efficiency of a MISO system. Background Art

[0002] In wireless communication systems for 6G, low-cost and low-power design solutions are a key factor in meeting higher communication requirements. Among them, reconfigurable intelligent surface (RIS) is a new paradigm with development prospects. RIS is an electromagnetic two-dimensional plane with programmable characteristics, which contains a large number of passive reflective elements. It can be deployed on a large scale as an auxiliary device in wireless networks to improve their spectrum capacity. Passive RIS has a "multiplicative fading effect", that is, the path loss of the RIS reflection link is the product of the path losses of the two sub-links from the transmitter to the RIS and from the RIS to the user, which seriously reduces the gain of the reflection link. In order to overcome the "multiplicative fading effect", an active RIS structure is proposed in wireless communication systems. The key feature of active RIS is that it can realize the function of amplifying the reflected signal by integrating the amplifier into the reflective element; active RIS compensates for the large path loss of the reflection link at the cost of additional power consumption, which is expected to overcome the "multiplicative fading effect". As one of the key technologies of 6G wireless networks, in order to fully utilize the advantages of active RIS, new structural design and optimization problem solving of active RIS have become one of the research hotspots. In the prior art, the common means to improve the energy efficiency of the active RIS-assisted MISO system are: 1) taking the maximum received signal-to-noise ratio as the optimization target; 2) taking the total rate maximization problem and power minimization problem as the optimization target; 3) taking the maximum energy efficiency problem as the optimization target, and discussing the impact of different constraints on the active RIS-assisted uplink wireless network. Although the above three methods can achieve the energy efficiency optimization of the MISO system, in the actual RIS-assisted MISO system communication, not all RIS branches need to participate in the optimization. If they are included in the optimization consideration range at this time, unnecessary energy loss will be increased, affecting energy efficiency.

[0003] Therefore, providing an energy efficiency optimization method that can solve the extra energy consumption caused by the RIS branch is a technical problem that needs to be solved. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a switch-assisted RIS circuit and a method for optimizing the energy efficiency of the MISO system. The power constraints of the base station and the active RIS are considered for the active RIS sub-connection architecture, and a new sub-connection architecture is proposed in which a Switcher module is added after each phase shift circuit to better achieve MISO energy efficiency optimization.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] According to a first aspect of the present invention, a method for optimizing the energy efficiency of a MISO system using a switch-assisted RIS is provided, the method comprising:

[0007] Improve the active RIS circuit, add switches to the phase shift circuit of each reflection unit, and use the improved active RIS circuit to assist the MISO system;

[0008] Calculating the signal-to-noise ratio, base station transmission power and active RIS transmission power of each user in the improved active RIS circuit-assisted MISO system, and calculating the total energy consumption of the MISO system based on the base station transmission power and the active RIS transmission power;

[0009] Based on the signal-to-noise ratio of each user and the total energy consumption of the MISO system, an energy efficiency optimization objective function of the MISO system is constructed, and based on the objective function, an energy efficiency optimization solution of the MISO system is solved.

[0010] As a preferred technical solution, the method for calculating the signal-to-noise ratio of each user is:

[0011]

[0012] in, represents the equivalent channel from the base station to the kth user, and G N×M They are the channel from the base station to the k-th user, the channel from the RIS to the k-th user, and the channel from the base station to the RIS; represents the precoding vector of the base station for the i-th transmitted data; represents the precoding matrix of active RIS; σ 2 , denote the channel noise covariance received by the user from the base station and the active RIS respectively; Ψ=diag(θΓa)diag(S j ), represents the phase shift diagonal matrix, represents the magnification factor vector; S j Indicates the switch status, S j =1 means the switch is closed, S j =0 indicates switch.

[0013] As a preferred technical solution, the method for calculating the base station transmit power, the active RIS transmit power and the total energy consumption of the MISO system is:

[0014] Calculate the base station transmit power and the active RIS transmit power:

[0015]

[0016]

[0017] Among them, P BS represents the base station transmission power; ξ and ζ represent the inverse of the energy conversion coefficient of the base station and the active RIS; w k represents the precoding vector of the data sent by the base station to the kth user; W BS represents the hardware power of the phase shift circuit in the active RIS; P RIS represents the transmission power of the active RIS; Ψ=diag(θΓa)diag(S j ), represents the phase shift diagonal matrix, represents the amplification factor vector; G represents the channel from the base station to the RIS; represents the channel noise covariance of the active RIS received by the user; S j Indicates the switching status of switch j, S j =1 means the switch is closed, S j =0 indicates switch; N indicates the number of switches; W PA Indicates the hardware power of the power amplifier;

[0018] The dissipated power of each user is obtained, and the total energy consumption of the MISO system is obtained by weighted summing up the dissipated power of each user, the transmission power of the base station and the transmission power of the active RIS.

[0019] As a preferred technical solution, the objective function for constructing the energy efficiency optimization of the MISO system includes:

[0020] The maximum value of the energy benefit of the MISO system is taken as the goal, and the base station transmission power constraint, active RIS transmission power constraint, phase shift circuit constraint, amplification factor constraint and switch constraint are constructed, and the expression is:

[0021]

[0022] in, represents the total information rate of the MISO system, P total represents the total energy consumption of the MISO system; and P BS Respectively represent the maximum transmit power and transmit power of the base station; and P RIS Respectively represent the maximum transmit power and transmit power of active RIS; θ n represents the phase shift matrix; a lrepresents the magnification factor vector; S j Indicates switch status.

[0023] As a preferred technical solution, the MISO system energy efficiency optimization solution is solved based on the objective function, including:

[0024] The energy efficiency optimization objective function of the MISO system is introduced into auxiliary variables to convert it into a convex optimization form;

[0025] The energy efficiency optimization objective function of the MISO system based on the convex optimization form uses the alternating solution method to obtain the energy efficiency solution of the MISO system.

[0026] As a preferred technical solution, the method of converting the MISO system energy efficiency optimization objective function into a convex optimization form is:

[0027] The nonlinear fractional form of the MISO system energy efficiency optimization objective function is converted into a linear form, and its expression is:

[0028]

[0029] Where W represents the precoding vector matrix of the base station to send data to the user, Θ represents the vector composed of the diagonal elements of the phase shift diagonal matrix; a represents the amplification factor; S j represents the switch condition; C1 represents the base station transmission power constraint; C2 represents the active RIS transmission power constraint; C3 represents the phase shift circuit constraint; C4 represents the amplification factor constraint; C5 represents the switch constraint; R sum represents the total information rate; η represents the energy efficiency; P total represents the total energy consumption of the MISO system; K represents the total number of users;

[0030] Introducing auxiliary variables and The linear form of the MISO system energy efficiency optimization objective function is converted into a convex optimization form, and its expression is:

[0031]

[0032]

[0033] Among them, Ψ=diag(θΓa)diag(S j ), represents the phase shift diagonal matrix, represents the magnification factor vector; μ k represents the first auxiliary variable; represents the equivalent channel from the base station to the kth user; w krepresents the precoding vector of the data sent by the base station to the kth user; v k represents the second auxiliary variable; represents the channel transposition from RIS to the kth user; η represents the energy efficiency; Θ represents the vector composed of the diagonal elements of the phase shift diagonal matrix; W represents the precoding process; σ 2 , They represent the channel noise covariance received by the user from the base station and the active RIS respectively.

[0034] As a preferred technical solution, the nonlinear fractional form of the MISO system energy efficiency optimization objective function is converted into a linear form using the Dinkelbach method.

[0035] As a preferred technical solution, the method of obtaining the MISO system energy efficiency solution pair using the alternating solution method is:

[0036] Within the constraints of the MISO system energy efficiency optimization objective function in the convex optimization form, the initial values ​​of the variables W, Θ, a, μ, and v are arbitrarily given, and the optimization problem is converted into a problem of solving the optimal solution of the switch;

[0037] Substitute the optimal switch solution into the MISO system energy efficiency optimization objective function in the convex optimization form and fix Θ,a,μ,v to solve the optimal solution for MISO system precoding;

[0038] Substitute the optimal solution of switch and the optimal solution of MISO system precoding into the convex optimization form of MISO system energy efficiency optimization objective function and fix the optimal solution of a, μ, and v phase shift circuit;

[0039] Substitute the optimal switch solution and the optimal power solution into the MISO system energy efficiency optimization objective function in the convex optimization form and fix μ,v to find the optimal solution of the amplification factor;

[0040] Substitute the optimal solution of switch, power and amplification factor into the convex optimization form of the MISO system energy efficiency optimization objective function and fix v to obtain the optimal solution of the first auxiliary variable μ;

[0041] The optimal solution of the switch, the optimal solution of the MISO system precoding, the optimal solution of the power, the optimal solution of the amplification factor and the optimal solution of the first auxiliary variable μ are substituted into the convex optimization form of the MISO system energy efficiency optimization objective function to obtain the optimal solution of the second auxiliary variable v.

[0042] As a preferred technical solution, the method for solving the switch optimal solution problem is to obtain the switch optimal solution through an exhaustive method.

[0043] According to a second aspect of the present invention, a switch-assisted RIS circuit is provided, comprising a plurality of reflection units, each of which comprises a patch, a phase shift circuit, a power amplifier and a switch, wherein the switch is located in each reflection unit and is connected in parallel with the phase shift circuit for controlling the corresponding phase shift circuit; the circuit is used to implement the above method.

[0044] Compared with the prior art, the present invention adds switches to each phase shift circuit for branch control on the basis of the existing active RIS circuit, finds the optimal solution of the optimal switch through the method, realizes shutting down the inactive RIS branch, reduces power consumption, and thus realizes the optimal energy efficiency of the MISO system. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 The switch-assisted RIS circuit architecture diagram of the present invention;

[0046] Figure 2 is a flow chart of the method of the present invention;

[0047] Figure 3 The following is a performance comparison diagram of different methods in the scenario of the embodiment of the present invention;

[0048] Figure 4 The figure is a performance comparison chart of different methods under scenario 2 in an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0050] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation, and may represent the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships, for example, "A and / or B" can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects before and after are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0051] The active RIS circuit includes multiple reflection units, and each reflection unit includes a patch, a phase shift circuit and a power amplifier. The present invention is improved on the basis of the prior art, and a switch is introduced into each reflection unit of each RIS circuit, which is connected in parallel with the phase shift circuit to control whether the phase shift circuit of the corresponding branch is turned on. The circuit architecture diagram is shown in FIG. Figure 1 As shown, and using the improved active RIS circuit, the Figure 2 The method shown is used to optimize the energy efficiency of the MISO system. The detailed steps include:

[0052] Set system parameters. In the MISO system assisted by active RIS, the number of transmitting antennas of the base station is M, each cell has K single-antenna users, the number of reflection units of active RIS is N, each power amplifier serves T RIS units, and the maximum transmission power of the base station and active RIS is and The channel noise received by the user from the base station and the active RIS has zero mean covariance σ 2 I and The channels from the base station to the kth user, the RIS to the kth user, and the base station to the RIS are respectively and G N×M , where: k = 1,…,K.

[0053] S1. Calculate the signal-to-noise ratio, base station transmission power and active RIS transmission power of each user in the improved active RIS circuit-assisted MISO system, and calculate the total energy consumption of the MISO system based on the base station transmission power and the active RIS transmission power.

[0054] S11. The method for calculating the signal-to-drying ratio of each user is:

[0055]

[0056] in, represents the equivalent channel from the base station to the kth user, and G N×M They are the channel from the base station to the k-th user, the channel from the RIS to the k-th user, and the channel from the base station to the RIS; represents the precoding vector of the base station for the i-th transmitted data; represents the precoding matrix of active RIS; σ 2 , denote the channel noise covariance received by the user from the base station and the active RIS respectively; Ψ=diag(θΓa)diag(S j ), represents the phase shift diagonal matrix, represents the magnification factor vector; S j Indicates the switch status, S j =1 means the switch is closed, S j =0 indicates switch.

[0057] S12. Calculate the base station transmit power and the active RIS transmit power:

[0058]

[0059]

[0060] Among them, P BS represents the base station transmission power; ξ and ζ represent the inverse of the energy conversion coefficient of the base station and the active RIS; w k represents the precoding vector of the data sent by the base station to the kth user; W BS represents the hardware power of the phase shift circuit in the active RIS; P RIS represents the transmission power of the active RIS; Ψ=diag(θΓa)diag(S j ), represents the phase shift diagonal matrix, represents the amplification factor vector; G represents the channel from the base station to the RIS; represents the channel noise covariance of the active RIS received by the user; S jIndicates the switching status of switch j, S j =1 means the switch is closed, S j =0 indicates switch; N indicates the number of switches; W PA Indicates the hardware power of the power amplifier.

[0061] S13, obtaining the dissipated power of each user, and performing weighted summation of the dissipated power of each user, the base station transmission power, and the transmission power of the active RIS to obtain the total energy consumption of the MISO system, which is expressed as:

[0062] P total =P BS +P RIS +KW U ,

[0063] Among them, P total represents the total energy consumption of the MISO system; P BS Represents the transmission power of the base station; P RIS represents the transmission power of active RIS; K represents the total number of users; W U The power dissipated by each user.

[0064] S2. Construct the MISO system energy efficiency optimization objective function based on the signal-to-noise ratio of each user and the total energy consumption of the MISO system, and solve the MISO system energy efficiency optimization solution based on the objective function.

[0065] S21. Construct the objective function of MISO system energy efficiency optimization:

[0066] S212. The energy efficiency of the system is defined as the total information rate R of the system. sum The total energy consumed by the system is:

[0067]

[0068] Where W represents the precoding vector matrix of the base station to send data to the user, Θ represents the vector composed of the diagonal elements of the phase shift matrix θ; a represents the amplification factor; S j Indicates switch status.

[0069] The maximum value of the energy benefit of the MISO system is taken as the goal, and the base station transmission power constraint, active RIS transmission power constraint, phase shift circuit constraint, amplification factor constraint and switch constraint are constructed, and the expression is:

[0070]

[0071] in, represents the total information rate of the MISO system, P totalrepresents the total energy consumption of the MISO system; and P BS Respectively represent the maximum transmit power and transmit power of the base station; and P RIS Respectively represent the maximum transmit power and transmit power of active RIS; θ n represents the phase shift matrix; a l represents the magnification factor vector; S j Indicates switch status.

[0072] S213. Use the Dinkelbach method to convert the nonlinear fractional form of the MISO system energy efficiency optimization objective function into a linear form.

[0073] Specifically, for any R sum ≥0 and P total >0, the energy efficiency η can reach the maximum value η opt The necessary and sufficient conditions are:

[0074]

[0075] in:

[0076]

[0077] Then, the linear expression of the MISO system energy efficiency optimization objective function is:

[0078]

[0079] Where W represents the precoding vector matrix of the base station to send data to the user, Θ represents the vector composed of the diagonal elements of the phase shift diagonal matrix; a represents the amplification factor; S j represents the switch condition; C1 represents the base station transmission power constraint; C2 represents the active RIS transmission power constraint; C3 represents the phase shift circuit constraint; C4 represents the amplification factor constraint; C5 represents the switch constraint; R sum represents the total information rate; η represents the energy efficiency; P total represents the total energy consumption of the MISO system; K represents the total number of users.

[0080] S214, introduce auxiliary variables and The linear form of the MISO system energy efficiency optimization objective function is converted into a convex optimization form, and its expression is:

[0081]

[0082]

[0083] Among them, Ψ=diag(θΓa)diag(S j ), represents the phase shift diagonal matrix, represents the magnification factor vector; μ k represents the first auxiliary variable; represents the equivalent channel from the base station to the kth user; w k represents the precoding vector of the data sent by the base station to the kth user; v k represents the second auxiliary variable; f k H represents the channel transposition from RIS to the kth user; η represents the energy efficiency; Θ represents the vector composed of the diagonal elements of the phase shift diagonal matrix; W represents the precoding process; σ 2 , They represent the channel noise covariance received by the user from the base station and the active RIS respectively.

[0084] S22. Obtain the MISO system energy efficiency solution based on the MISO system energy efficiency optimization objective function in convex optimization form.

[0085] It can be seen from the objective function in step S214 that the objective function includes six variables. When performing the optimization calculation, this embodiment adopts the alternating solution method to obtain the MISO system energy efficiency solution, which is specifically:

[0086] Within the constraints of the MISO system energy efficiency optimization objective function in the convex optimization form, the initial values ​​of the variables W, Θ, a, μ, and v are arbitrarily given, and the optimization problem is converted into a problem of solving the optimal solution of the switch. In detail, this embodiment adopts an exhaustive method to obtain the optimal solution of the switch.

[0087] Substitute the optimal switch solution into the energy efficiency optimization objective function of the MISO system in the convex optimization form and fix Θ,a,μ,v to solve the optimal solution for the MISO system precoding.

[0088] Substitute the optimal solution of the switch and the optimal solution of the MISO system precoding into the convex optimization form of the MISO system energy efficiency optimization objective function and fix the optimal solution of the a, μ, and v phase shift circuits.

[0089] Substitute the optimal switch solution and the optimal power solution into the energy efficiency optimization objective function of the MISO system in the convex optimization form and fix μ,v to obtain the optimal solution of the amplification factor.

[0090] Substitute the optimal solution of switch, power and amplification factor into the convex optimization form of the MISO system energy efficiency optimization objective function and fix v to obtain the optimal solution of the first auxiliary variable μ.

[0091] The optimal solution of the switch, the optimal solution of the MISO system precoding, the optimal solution of the power, the optimal solution of the amplification factor and the optimal solution of the first auxiliary variable μ are substituted into the convex optimization form of the MISO system energy efficiency optimization objective function to obtain the optimal solution of the second auxiliary variable v.

[0092] In order to verify that the above-mentioned method and the corresponding circuit can effectively improve the optimization of the energy efficiency of the MISO system, two sets of scenarios are set for verification.

[0093] Scenario 1: The number of transmitting antennas of the base station is set to six, the number of reflection units of the switch-assisted active RIS is 256, and the number of single-antenna users is 4. When the location of the base station is taken as the origin, the users are located at different locations. The method of this application is used to optimize the energy efficiency of the MISO system, and the active RIS fully connected circuit solution and the active RIS sub-connected circuit solution are used for optimization in the same scenario. The results are as follows: Figure 3 As shown, it can be seen that the energy efficiency of the method and the corresponding circuit proposed in this embodiment is improved by about 8% compared with the sub-connection architecture of the existing active RIS-assisted MISO system, and is improved by about 30% compared with the full-connection architecture of the existing active RIS-assisted MISO system.

[0094] Scenario 2: Assuming that the number of transmitting antennas of the base station is six, the number of single-antenna users is four, and the user's position is 100 meters and 0 meters in the two-dimensional coordinate system, and the maximum transmitting power of the base station changes, the method provided in this embodiment, that is, the circuit, is used to compare the energy efficiency optimization performance of the MISO system based on sub-connection and full-connection active RIS circuit assistance in the prior art. The results are as follows: Figure 4 As shown, it can be seen that the energy efficiency improved by the method and corresponding circuit provided by this embodiment is higher than that of the sub-connection architecture and the full-connection architecture of the existing active RIS-assisted MISO system.

[0095] In summary, the method provided in this embodiment and the corresponding switch-assisted RIS circuit are feasible and have superior performance.

[0096] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for optimizing the energy efficiency of a MISO system using a switch-assisted RIS, characterized in that: The method includes: Improve the active RIS circuit, add switches to the phase shift circuit of each reflection unit, and use the improved active RIS circuit to assist the MISO system; Calculating the signal-to-noise ratio, base station transmission power and active RIS transmission power of each user in the improved active RIS circuit-assisted MISO system, and calculating the total energy consumption of the MISO system based on the base station transmission power and the active RIS transmission power; Based on the signal-to-noise ratio of each user and the total energy consumption of the MISO system, an energy efficiency optimization objective function of the MISO system is constructed, and based on the objective function, an energy efficiency optimization solution of the MISO system is solved.

2. The method for optimizing the energy efficiency of a MISO system by using a switch-assisted RIS according to claim 1, characterized in that: The method for calculating the signal-to-noise ratio of each user is: in, represents the equivalent channel from the base station to the kth user, and G N ×M They are the channel from the base station to the k-th user, the channel from the RIS to the k-th user, and the channel from the base station to the RIS; represents the precoding vector of the base station for the i-th transmitted data; represents the precoding matrix of active RIS; σ 2 , denote the channel noise covariance received by the user from the base station and the active RIS respectively; Ψ=diag(θΓa)diag(S j ), represents the phase shift diagonal matrix, represents the magnification factor vector; S j Indicates the switch status, S j =1 means the switch is closed, S j =0 indicates switch.

3. The method for optimizing the energy efficiency of a MISO system by using a switch-assisted RIS according to claim 1, characterized in that: The method for calculating the base station transmit power, the active RIS transmit power and the total energy consumption of the MISO system is: Calculate the base station transmit power and the active RIS transmit power: Among them, P BS represents the base station transmission power; ξ and ζ represent the inverse of the energy conversion coefficient of the base station and the active RIS; w k represents the precoding vector of the data sent by the base station to the kth user; W BS represents the hardware power of the phase shift circuit in the active RIS; P RIS represents the transmission power of the active RIS; Ψ=diag(θΓa)diag(S j ), represents the phase shift diagonal matrix, represents the amplification factor vector; G represents the channel from the base station to the RIS; represents the channel noise covariance of the active RIS received by the user; S j Indicates the switching status of switch j, S j =1 means the switch is closed, S j =0 indicates switch; N indicates the number of switches; W PA Indicates the hardware power of the power amplifier; The dissipated power of each user is obtained, and the total energy consumption of the MISO system is obtained by weighted summing up the dissipated power of each user, the transmission power of the base station and the transmission power of the active RIS.

4. The method of optimizing the energy efficiency of a MISO system by using a switch-assisted RIS according to claim 1, characterized in that: The objective function for constructing the MISO system energy efficiency optimization includes: The maximum value of the energy benefit of the MISO system is taken as the goal, and the base station transmission power constraint, active RIS transmission power constraint, phase shift circuit constraint, amplification factor constraint and switch constraint are constructed, and the expression is: in, represents the total information rate of the MISO system, P total represents the total energy consumption of the MISO system; and P BS Respectively represent the maximum transmit power and transmit power of the base station; and P RIS Respectively represent the maximum transmit power and transmit power of active RIS; θ n represents the phase shift matrix; a l represents the magnification factor vector; S j Indicates switch status.

5. The method for optimizing the energy efficiency of a MISO system by using a switch-assisted RIS according to claim 4, characterized in that: Solving the MISO system energy efficiency optimization scheme based on the objective function includes: The energy efficiency optimization objective function of the MISO system is introduced into auxiliary variables to convert it into a convex optimization form; The energy efficiency optimization objective function of the MISO system based on the convex optimization form uses the alternating solution method to obtain the energy efficiency solution of the MISO system.

6. The method for optimizing the energy efficiency of a MISO system by using a switch-assisted RIS according to claim 5, characterized in that: The method of converting the MISO system energy efficiency optimization objective function into a convex optimization form is: The nonlinear fractional form of the MISO system energy efficiency optimization objective function is converted into a linear form, and its expression is: Where W represents the precoding vector matrix of the base station to send data to the user, Θ represents the vector composed of the diagonal elements of the phase shift diagonal matrix; a represents the amplification factor; S j represents the switch condition; C1 represents the base station transmission power constraint; C2 represents the active RIS transmission power constraint; C3 represents the phase shift circuit constraint; C4 represents the amplification factor constraint; C5 represents the switch constraint; R sum represents the total information rate; η represents the energy efficiency; P total represents the total energy consumption of the MISO system; K represents the total number of users; Introducing auxiliary variables and The linear form of the MISO system energy efficiency optimization objective function is converted into a convex optimization form, and its expression is: subject to C1,C2,C3,C4,C5, Among them, Ψ=diag(θΓa)diag(S j ), represents the phase shift diagonal matrix, represents the magnification factor vector; μ k represents the first auxiliary variable; represents the equivalent channel from the base station to the kth user; w k represents the precoding vector of the data sent by the base station to the kth user; v k represents the second auxiliary variable; represents the channel transposition from RIS to the kth user; η represents the energy efficiency; Θ represents the vector composed of the diagonal elements of the phase shift diagonal matrix; W represents the precoding process; σ 2 , They represent the channel noise covariance received by the user from the base station and the active RIS respectively.

7. The method for optimizing the energy efficiency of a MISO system by using a switch-assisted RIS according to claim 6, characterized in that: The nonlinear fractional form of the MISO system energy efficiency optimization objective function is converted into a linear form using the Dinkelbach method.

8. The method for optimizing the energy efficiency of a MISO system by using a switch-assisted RIS according to claim 5, characterized in that: The method for obtaining the energy efficiency scheme pair of the MISO system by using the alternating solution method is: Within the constraints of the MISO system energy efficiency optimization objective function in the convex optimization form, the initial values ​​of the variables W, Θ, a, μ, and v are arbitrarily given, and the optimization problem is converted into a problem of solving the optimal solution of the switch; Substitute the optimal switch solution into the MISO system energy efficiency optimization objective function in the convex optimization form and fix Θ,a,μ,v to solve the optimal solution for MISO system precoding; Substitute the optimal solution of switch and the optimal solution of MISO system precoding into the convex optimization form of MISO system energy efficiency optimization objective function and fix the optimal solution of a, μ, and v phase shift circuit; Substitute the optimal switch solution and the optimal power solution into the MISO system energy efficiency optimization objective function in the convex optimization form and fix μ,v to find the optimal solution of the amplification factor; Substitute the optimal solution of switch, power and amplification factor into the convex optimization form of the MISO system energy efficiency optimization objective function and fix v to obtain the optimal solution of the first auxiliary variable μ; The optimal solution of the switch, the optimal solution of the MISO system precoding, the optimal solution of the power, the optimal solution of the amplification factor and the optimal solution of the first auxiliary variable μ are substituted into the convex optimization form of the MISO system energy efficiency optimization objective function to obtain the optimal solution of the second auxiliary variable v.

9. The method for optimizing the energy efficiency of a MISO system by using a switch-assisted RIS according to claim 8, characterized in that: The method for solving the optimal solution problem of the switch is to obtain the optimal solution of the switch by exhaustive method.

10. A switch-assisted RIS circuit, comprising a plurality of reflection units, each of which comprises a patch, a phase shift circuit and a power amplifier, characterized in that: The reflection unit further comprises a switch, which is located in each reflection unit and connected in parallel with the phase shift circuit for controlling the corresponding phase shift circuit; the circuit is used to implement the method as claimed in claims 1 to 9.

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