Signal transmission methods, devices, equipment and storage media

Abstract

This application provides a signal transmission method, apparatus, device, and storage medium, relating to the field of communication technology. The method includes: acquiring the phase shift matrix of a smart metasurface (RIS); the phase shift matrix representing the phase shift values ​​of multiple reflective elements in the RIS; acquiring a phase-shifted particle swarm; the phase-shifted particle swarm comprising multiple particles; each particle representing a potential optimal solution to the RIS phase shift matrix; acquiring feedback information from a user equipment (UE) to each particle; the feedback information representing the signal strength received by the UE; iteratively searching for the optimal solution particle based on the feedback information; and controlling multiple reflective elements to reflect signals transmitted by the base station to the UE according to the phase shift matrix corresponding to the optimal solution particle. This method is applicable to addressing the challenge of developing signal interference cancellation schemes during signal transmission.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to a signal transmission method, apparatus, device and storage medium. Background Technology

[0002] With the continuous advancement of technologies such as ultra-dense networks, massive MIMO, and millimeter-wave communication, the 5G wireless network has basically achieved wireless connectivity of massive MIMO base stations.

[0003] The deployment of large-scale MIMO base stations in ultra-dense networks exacerbates network interference problems. Currently, interference cancellation technologies for large-scale MIMO base stations are generally complex and difficult to develop. Summary of the Invention

[0004] To address the aforementioned technical issues, this application provides a signal transmission method, apparatus, device, and storage medium that can optimize the phase shift matrix of a smart metasurface RIS using feedback information from user equipment, thereby reducing network interference and lowering development difficulty.

[0005] In a first aspect, this application provides a signal transmission method, the method comprising: acquiring a phase shift matrix of a smart metasurface RIS; the phase shift matrix being used to represent the phase shift values ​​of multiple reflective elements in the RIS; acquiring a phase shift particle swarm; the phase shift particle swarm comprising multiple particles; each of the multiple particles being used to represent a potential optimal solution of the RIS phase shift matrix; acquiring feedback information from a user equipment UE to each particle; the feedback information being used to represent the signal strength received by the UE; iteratively searching for the optimal solution particle by the phase shift particle swarm based on the feedback information; and controlling multiple reflective elements to reflect the signal transmitted by the base station to the UE according to the phase shift matrix corresponding to the optimal solution particle.

[0006] In one possible implementation, for each iteration, the optimal solution particle is iteratively searched for based on feedback information in the phase-shifted particle swarm, including: updating the optimal position of each particle in the phase-shifted particle swarm according to the feedback information; the optimal position is the position with the highest signal-to-noise ratio between the current position and the historical position of each particle; determining the global optimal position of the current phase-shifted particle swarm based on the optimal position of each particle; and determining the particle at the global optimal position as the optimal solution particle.

[0007] Optionally, the method further includes: for each particle in the phase-shifted particle swarm, determining whether the current velocity of the particle is greater than a preset velocity threshold; if so, determining the velocity of the particle at the next moment as the velocity threshold, and updating the position of the particle.

[0008] Optionally, the method further includes: if the current velocity of the particle is less than the velocity threshold, then the velocity of the particle is updated according to the following formula: velocity at time (k+1) = velocity at time k × inertia factor + velocity update factor × (global best position of phase-shifted particle swarm - position of the particle at time k).

[0009] Optionally, the condition for iterative convergence is: the number of iterations reaches a preset threshold, or the difference in signal-to-noise ratio between the global best positions obtained from two iterations is less than a preset error threshold.

[0010] In one possible implementation, the UE includes multiple UEs; multiple reflecting elements are controlled to reflect signals transmitted by the base station to the UEs according to the phase shift matrix corresponding to the optimal solution particle, including: under the constraint that the received power of the first UE is greater than a power threshold, the target beamforming matrix of the base station is determined with the goal of minimizing the transmitted power of the base station; the first UE is any one of the multiple UEs; under the constraint that the base station transmits signals according to the target beamforming matrix, the phase shift matrix corresponding to the optimal solution particle is modified with the goal of maximizing the received power of the first UE, to obtain a modified phase shift matrix; under the constraint that the received power of multiple UEs is greater than a power threshold, the modified phase shift matrix is ​​modified multiple times alternately to obtain a target phase shift matrix; and multiple reflecting elements are controlled to reflect signals transmitted by the base station to the UEs according to the target phase shift matrix.

[0011] Optionally, under the constraint that the received power of the first UE is greater than a power threshold, the target beamforming matrix of the base station is determined with the objective of minimizing the transmit power of the base station, including: determining the target beamforming matrix of the base station according to the following formula:

[0012]

[0013] Where W represents the beamforming matrix of the base station; ||w|| 2 σ represents the base station's transmit power; q represents the phase shift matrix corresponding to the optimal solution particle; h1 represents the path of the signal transmitted by the base station and reflected by the RIS according to the phase shift matrix corresponding to the optimal solution particle to the first UE; h2 represents the direct path of the signal transmitted from the base station to the first UE; γ represents the preset signal-to-interference ratio threshold; σ represents the signal-to-interference ratio threshold. 2 q represents the noise power in a wireless environment. n This represents the phase shift value of the nth reflecting element in the RIS;

[0014] Under the constraint that the base station transmits signals according to the target beamforming matrix, the phase shift matrix is ​​modified to maximize the received power of the first UE, resulting in the modified phase shift matrix, which includes:

[0015] The phase shift matrix is ​​corrected according to the following formula:

[0016]

[0017] Where, ‖h1+h2‖ 2 This indicates the received power of the first UE.

[0018] The signal transmission method provided in this application embodiment can use the feedback information from the user equipment as a reference to solve the phase shift matrix of the smart metasurface according to the particle swarm optimization algorithm to obtain the optimal solution particle. Based on the phase shift matrix corresponding to the optimal solution particle, the smart metasurface is controlled to reflect the signal emitted by the base station. The signal reflected to the user equipment is stronger, thereby reducing the interference of other base station signals to the user equipment. Moreover, the algorithm only needs to consider the feedback information of the user equipment, and the complexity does not increase with the increase of the number of reflection units in the smart metasurface. The phase shift matrix design is relatively simple, reducing the development difficulty.

[0019] Furthermore, to address signal interference between multiple user equipments within the coverage area of ​​the same base station, this method can also perform alternating convex optimization on these multiple user equipments to obtain a target phase shift matrix under the constraint that the received power of all multiple user equipments is greater than a power threshold. The intelligent metasurface is then controlled to reflect the base station signal according to the target phase shift matrix, resulting in stronger signal strength received by the user equipments, thereby reducing signal interference between user equipments within the coverage area of ​​the same base station.

[0020] In addition, the signal emitted by the intelligent metasurface reflective base station can refract signals that cannot be transmitted through a direct transmission path to the user equipment, thereby expanding the coverage of the base station, reducing the number of base stations to be deployed, and saving hardware costs.

[0021] Secondly, this application provides a signal transmission device, which includes an acquisition module and a processing module.

[0022] The acquisition module is used to acquire the phase shift matrix of the intelligent metasurface RIS; the phase shift matrix is ​​used to represent the phase shift values ​​of multiple reflective elements in the RIS; acquire the phase shift particle swarm; the phase shift particle swarm includes multiple particles; each of the multiple particles is used to represent a potential optimal solution of the RIS phase shift matrix; acquire the feedback information of the user equipment UE to each particle; the feedback information is used to represent the signal strength received by the UE.

[0023] The processing module is used to iteratively search for the optimal solution particle by the phase-shifted particle swarm based on feedback information; and to control multiple reflective elements to reflect the signal transmitted by the UE to the base station according to the phase-shift matrix corresponding to the optimal solution particle.

[0024] Optionally, for each iteration, the processing module is specifically used to update the optimal position of each particle in the phase-shifted particle swarm based on the feedback information; the optimal position is the position with the highest signal-to-noise ratio between the current position and the historical position of each particle; the global optimal position of the current phase-shifted particle swarm is determined based on the optimal position of each particle; and the particle at the global optimal position is determined as the optimal solution particle.

[0025] Optionally, the processing module is also used to determine whether the current velocity of each particle in the phase-shifted particle swarm is greater than a preset velocity threshold; if so, the velocity of the particle at the next moment is determined as the velocity threshold, and the position of the particle is updated.

[0026] Optionally, the processing module is also configured to update the particle’s velocity according to the following formula if the particle’s current velocity is less than the velocity threshold: velocity at time (k+1) = velocity at time k × inertia factor + velocity update factor × (global best position of phase-shifted particle swarm - position of the particle at time k).

[0027] Optionally, the condition for iterative convergence is: the number of iterations reaches a preset threshold, or the difference in signal-to-noise ratio between the global best positions obtained from two iterations is less than a preset error threshold.

[0028] Optionally, the UE includes multiple processing modules, specifically configured to determine the target beamforming matrix of the base station with the objective of minimizing the base station's transmit power, under the constraint that the received power of the first UE is greater than a power threshold; the first UE is any one of the multiple UEs; under the constraint that the base station transmits signals according to the target beamforming matrix, with the objective of maximizing the received power of the first UE, the phase shift matrix corresponding to the optimal solution particle is corrected to obtain the corrected phase shift matrix; under the constraint that the received power of multiple UEs is greater than the power threshold, the corrected phase shift matrix is ​​alternately corrected multiple times to obtain the target phase shift matrix; and multiple reflecting elements are controlled to reflect the signal transmitted by the base station to the UE according to the target phase shift matrix.

[0029] Optionally, the processing module is specifically used to determine the target beamforming matrix of the base station according to the following formula:

[0030]

[0031] Where W represents the beamforming matrix of the base station; ||w|| 2 σ represents the base station's transmit power; q represents the phase shift matrix corresponding to the optimal solution particle; h1 represents the path of the signal transmitted by the base station and reflected by the RIS according to the phase shift matrix corresponding to the optimal solution particle to the first UE; h2 represents the direct path of the signal transmitted from the base station to the first UE; γ represents the preset signal-to-interference ratio threshold; σ represents the signal-to-interference ratio threshold. 2q represents the noise power in a wireless environment. n This represents the phase shift value of the nth reflecting element in the RIS;

[0032] The phase shift matrix is ​​corrected according to the following formula:

[0033]

[0034] Where, ‖h1+h2‖ 2 This indicates the received power of the first UE.

[0035] Thirdly, this application provides a computer program product that, when run on an electronic device, causes the electronic device to perform the steps of the related method described in the first aspect, so as to implement the method described in the first aspect.

[0036] Fourthly, this application provides an electronic device including a processor and a memory; the memory stores processor-executable instructions; when the processor is configured to execute the instructions, the electronic device performs the method described in the first aspect above.

[0037] Fifthly, this application provides a readable storage medium comprising: software instructions; when the software instructions are executed in an electronic device, they cause the electronic device to perform the method described in the first aspect above.

[0038] The beneficial effects of the second to fifth aspects mentioned above can be referred to the first aspect, and will not be repeated here. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 A schematic diagram illustrating the deployment of smart metasurfaces for eliminating interference at the edge of a cellular network;

[0041] Figure 2 This is a schematic diagram of the composition of the signal transmission system provided in the embodiments of this application;

[0042] Figure 3 A schematic diagram illustrating the composition of the electronic device provided in the embodiments of this application;

[0043] Figure 4 A schematic flowchart illustrating the signal transmission method provided in an embodiment of this application;

[0044] Figure 5 This is a schematic diagram of the architecture of a wireless communication system for a multi-user device with intelligent metasurface assistance, provided in an embodiment of this application.

[0045] Figure 6 This is a schematic diagram of the composition of the signal transmission device provided in the embodiments of this application. Detailed Implementation

[0046] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] It should be noted that in the embodiments of this application, the words "exemplarily" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design scheme described as "exemplarily" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the words "exemplarily" or "for example" is intended to present the relevant concepts in a specific manner.

[0048] To facilitate a clear description of the technical solutions of the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish the same or similar items with essentially the same function and effect. Those skilled in the art can understand that the terms "first" and "second" are not intended to limit the quantity or execution order.

[0049] With the continuous advancement of technologies such as ultra-dense networks, massive MIMO, and millimeter-wave communication, the 5G wireless network has basically achieved wireless connectivity of massive MIMO base stations.

[0050] The deployment of large-scale MIMO base stations in ultra-dense networks exacerbates network interference problems.

[0051] Currently, signals transmitted by base stations can be reflected back to user equipment using reconfigurable intelligent surfaces (RIS).

[0052] For example, Figure 1 A schematic diagram illustrating the deployment of smart metasurfaces for eliminating interference at the edge of a cellular network. (Example) Figure 1As shown, by intelligently adjusting the phase shift values ​​of all reflective elements according to the dynamic wireless channel, the signal reflected by the intelligent metasurface can be in a constructive or destructive phase with the unreflected signal at a nearby user receiver, thereby increasing the required signal power and / or suppressing co-channel interference, thus significantly improving communication performance without the need to deploy additional active base stations or relay equipment.

[0053] By analyzing the signals received by the user equipment, the signal-to-interference ratio (SIR) of the user equipment can be expressed as: SIR of user equipment = Channel 1 × Useful signal power / (Noise power + Channel 2 × Interfering base station power + Cascaded Channel 1 × Phase shift matrix of smart metasurface × Cascaded Channel 2 × Interfering base station power).

[0054] Based on the above expression, we can design the phase shift matrix of the smart metasurface to make (channel 2 × interference base station power + cascaded channel 1 × smart metasurface phase shift matrix × cascaded channel 2 × interference base station power) as small as possible, thus obtaining the maximum signal-to-interference ratio of the user equipment.

[0055] However, traditional solutions require complex channel estimation of the cascaded channels from the interfering base station to the user equipment and on both sides of the smart metasurface in order to correspond to the phase shift matrix involved in the smart metasurface. Moreover, the algorithm complexity generally increases with the number of reflective elements of the smart metasurface. Such solutions are relatively complex and difficult to develop.

[0056] Based on this, this application provides a signal transmission method that can optimize the phase shift matrix of the intelligent metasurface RIS by using feedback information from user equipment, thereby reducing network interference and lowering development difficulty.

[0057] The following description is provided in conjunction with the accompanying drawings.

[0058] Figure 2 This is a schematic diagram illustrating the composition of a signal transmission system provided in an embodiment of this application. Figure 2 As shown, the system may include:

[0059] User equipment (UE) 100, intelligent metasurface 200, control device 300, and base station 400.

[0060] User equipment 100, smart metasurface 200, and base station 400 can be connected via a wireless network. Smart metasurface 200 and control device 300 can be connected via a wired or wireless network.

[0061] User equipment 100 may be a mobile phone, tablet computer, wearable device, in-vehicle device, augmented reality (AR) / virtual reality (VR) device, laptop computer, ultra-mobile personal computer (UMPC), netbook, personal digital assistant (PDA), etc. This embodiment of the invention does not limit the specific type of terminal device 100.

[0062] User equipment 100 can receive wireless signals reflected by smart metasurface 200 and transmitted by base station 400; user equipment 100 can also transmit wireless signals to base station 400 through smart metasurface 200.

[0063] Smart Metasurface 200 is an artificial electromagnetic surface structure with programmable electromagnetic properties. It consists of a large number of meticulously designed electromagnetic units (or reflective elements). Through control circuits, the electromagnetic properties of these units can be dynamically adjusted, enabling intelligent reconstruction of wireless signal propagation characteristics in three-dimensional space. This overcomes the limitations of passive adaptation to traditional wireless environments. As a fundamental innovative technology, Smart Metasurface 200 offers advantages such as low cost, low power consumption, and easy deployment. Its applications include deterministic wireless transmission, wireless coverage gap filling, wireless coverage extension, wireless system capacity enhancement, and coverage in specialized scenarios such as indoor and vehicle environments, demonstrating broad prospects for technological development and engineering applications.

[0064] The control device 300 can be an electronic device with computing processing capabilities, such as a computer or server. The server can be a single server or a server cluster consisting of multiple servers. In some embodiments, the server cluster can also be a distributed cluster. Optionally, the server can also be implemented on a cloud platform, such as a private cloud, public cloud, hybrid cloud, community cloud, distributed cloud, inter-cloud, and multi-cloud, or any combination thereof. This application does not impose limitations on this.

[0065] The control device 300 can control and change the phase shift matrix of the smart metasurface 200 to transmit wireless signals between the base station 400 and the user equipment 100 according to the signal transmission method in the following method embodiments. Specific functions are described in the following method embodiments and will not be repeated here.

[0066] In some embodiments, the control device 300 can control and change the phase shift matrix of the smart metasurface 200 by sending control commands to the smart metasurface 200.

[0067] For example, as described above, the smart metasurface 200 and the control device can be connected via a wired or wireless network. This wired or wireless network may include one or more media or devices capable of transmitting control commands from the control device 300 to the smart metasurface 200.

[0068] In some embodiments, the wired or wireless network may include one or more communication media that enable the control device 300 to transmit control commands directly to the smart metasurface 200 in real time. In this embodiment, the control device 300 may modulate the control commands according to a communication standard (e.g., a wireless communication protocol) and transmit the modulated control commands to the smart metasurface 200. The one or more communication media may include wireless and / or wired communication media, such as radio frequency (RF) spectrum or one or more physical transmission lines. Optionally, the one or more communication media may form part of a packet-based network, such as a local area network, a wide area network, or a global network (e.g., the Internet). Optionally, the one or more communication media may include a router, switch, base station, or other devices facilitating communication from the control device 300 to the smart metasurface 200.

[0069] It should be noted that, Figure 2 The example shown uses the control device 300 and the smart metasurface 200 as independent devices. Optionally, the control device 300 and the smart metasurface 200 can also be combined into one device, that is, the control device 300 or its corresponding function and the smart metasurface 200 or its corresponding function can be integrated into the same device. For example, a smart metasurface with control function or other devices. This application does not limit this.

[0070] Base station 400 can be a next-generation node (gNB) or an evolved node (eNB), etc. This application embodiment does not limit the specific type of base station 400.

[0071] The signal transmission method provided in this application embodiment is executed by the aforementioned control device 300. As described above, the control device 300 can be an electronic device with computing processing capabilities, such as a computer or server. Optionally, the control device 300 can also be a processor in the aforementioned electronic device; or, the control device 300 can also be an application (APP) installed in the aforementioned electronic device that provides control functions; or, the control device 300 can also be a functional module in the aforementioned electronic device used to perform control functions, etc. This application embodiment does not impose any limitations on these aspects.

[0072] For simplicity, the following description will use the control device 300 as an electronic device.

[0073] Figure 3 This is a schematic diagram illustrating the composition of an electronic device provided in an embodiment of this application. For example... Figure 3 As shown, the electronic device may include: a processor 10, a memory 20, a communication line 30, a communication interface 40, and an input / output interface 50.

[0074] The processor 10, memory 20, communication interface 40, and input / output interface 50 can be connected via communication line 30.

[0075] The processor 10 is used to execute instructions stored in the memory 20 to implement the signal transmission method provided in the following embodiments of this application. The processor 10 may be a central processing unit (CPU), a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller (MCU) / single-chip microcomputer / microcontroller, a programmable logic device (PLD), or any combination thereof. The processor 10 may also be any other device with processing capabilities, such as a circuit, device, or software module; this application embodiment does not limit this. In one example, the processor 10 may include one or more CPUs, for example... Figure 3 CPU0 and CPU1 are included. As an optional implementation, the image display device may include multiple processors; for example, in addition to processor 10, it may also include processor 60. Figure 3 (The example shown is a dashed line).

[0076] The memory 20 is used to store instructions. For example, the instructions may be computer programs. Optionally, the memory 20 may be a read-only memory (ROM) or other type of static storage device that can store static information and / or instructions; it may also be a random access memory (RAM) or other type of dynamic storage device that can store information and / or instructions; it may also be an electrically erasable programmable read-only memory (EEPROM), a CD-ROM or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media, or other magnetic storage devices, etc. The embodiments of this application do not limit this.

[0077] It should be noted that the memory 20 can exist independently of the processor 10 or it can be integrated with the processor 10. The memory 20 can be located inside or outside the electronic device, and this application embodiment does not impose any restrictions on this.

[0078] Communication line 30 is used to transmit information between the components included in the electronic device.

[0079] The communication interface 40 is used to communicate with other devices (such as the aforementioned smart metasurface 200) or other communication networks. These other communication networks can be Ethernet, radio access networks (RAN), wireless local area networks (WLAN), etc. The communication interface 40 can be a module, circuit, transceiver, or any device capable of enabling communication.

[0080] Input / output interface 50 is used to enable human-computer interaction between users and electronic devices. This includes, for example, gesture-based, text-based, or voice-based interactions between users and electronic devices.

[0081] For example, the input / output interface 50 can be a keyboard or a mouse. Action or text interaction between the user and the electronic device can be achieved through the keyboard or mouse.

[0082] It should be noted that, Figure 2 The structures shown do not constitute a limitation on electronic devices, except... Figure 3 In addition to the components shown, electronic devices may include more or fewer components than illustrated, or combinations of certain components, or different component arrangements.

[0083] The signal transmission method provided in the embodiments of this application will now be described in conjunction with the accompanying drawings.

[0084] Figure 4 This is a flowchart illustrating the signal transmission method provided in an embodiment of this application. Figure 4 As shown, the method includes steps S101 to S105.

[0085] S101, Electronic device acquires the phase shift matrix of the intelligent metasurface RIS.

[0086] As mentioned above, the RIS can include multiple reflective elements, and the phase shift matrix here can be used to represent the phase shift values ​​of the multiple reflective elements in the RIS.

[0087] For example, taking a smart metasurface with L reflective elements as an example, the phase shift matrix can be represented as H = [a1, a2, ..., aL], where each element ai (i = 1, 2, ..., L) in H represents the phase shift value of the i-th reflective element.

[0088] For example, the electronic device can randomly generate a phase shift matrix of a RIS (Regression-Oriented System), or it can receive a phase shift matrix input by a manager through the aforementioned input / output interface. This application does not impose any limitations on this.

[0089] S102, Electronic equipment acquires phase-shifted particle swarm.

[0090] The phase-shifting particle swarm can include multiple particles, each representing a potential optimal solution in the RIS phase-shifting matrix. The specific process of acquiring the phase-shifting particle swarm in the electronic device can be referred to in section S101 above, and will not be repeated here.

[0091] For example, taking the arbitrary generation of n possible phase shift matrices as an example, the phase-shifting particle swarm can be represented as F = {H1, H2, ..., Hn}, where each particle Hj (j = 1, 2, ..., N) in F represents a potential optimal solution to the phase shift matrix of RIS. In the subsequent process, the electronic device can perform optimization iterations, continuously moving the particles H in F toward the optimal solution, thereby obtaining the optimal smart metasurface matrix.

[0092] S103. The electronic device acquires the feedback information of the user equipment (UE) for each particle.

[0093] The feedback information is used to indicate the signal strength received by the UE.

[0094] For example, the feedback information can be the average received signal strength indication (RSSI) within a preset period, fed back by the user equipment through the uplink channel. Again, taking the example of n possible phase shift matrices arbitrarily generated by the aforementioned electronic device, the feedback information obtained by the electronic device can be represented as M(F) = {M1, M2, ..., Mn}. M1 represents the average RSSI within a preset period, fed back by the user equipment when the RIS reflects a signal according to the phase shift matrix represented by H1; M2 represents the average RSSI within a preset period, fed back by the user equipment when the RIS reflects a signal according to the phase shift matrix represented by H2; ... Mn represents the average RSSI within a preset period, fed back by the user equipment when the RIS reflects a signal according to the phase shift matrix represented by Hn. The preset period can be set by the administrator in the electronic device through the aforementioned input / output interface. For example, the preset period can be 3 seconds or 5 seconds, etc. This application embodiment does not limit the specific duration of the preset period.

[0095] S104. The electronic device iteratively searches for the optimal solution particle based on feedback information in the phase-shifted particle swarm.

[0096] In one possible implementation, for each iteration, S104 above may specifically include the following steps:

[0097] Step 1: The electronic device updates the optimal position of each particle in the phase-shifted particle swarm based on the feedback information.

[0098] The optimal position is the position with the highest signal-to-noise ratio between the current position and the historical position of each particle.

[0099] Step 2: The electronic device determines the global optimal position of the current phase-shifted particle swarm based on the optimal position of each particle.

[0100] For example, an electronic device can record the optimal position and corresponding signal-to-noise ratio of each particle, as well as the local optimal position and corresponding signal-to-noise ratio, and take the optimal position with the highest signal-to-noise ratio as the global optimal position of the current phase-shifted particle swarm.

[0101] Step 3: The electronic device identifies the particle in the globally optimal position as the optimal solution particle.

[0102] Optionally, for multiple iterations, the electronic device can update the optimal position and corresponding signal-to-noise ratio of each particle, the global optimal position and corresponding signal-to-noise ratio of the phase-shifted particle swarm, and the local optimal position and corresponding signal-to-noise ratio based on the signal-to-noise ratio.

[0103] Optionally, for each particle, the electronic device can also determine whether the current position is the optimal position for that particle. If not, it updates and records the optimal position for that particle, and updates the global optimal position and the corresponding signal-to-noise ratio, as well as the local optimal position and the corresponding signal-to-noise ratio.

[0104] Optionally, the method may further include: for each particle in the phase-shifted particle swarm, the electronic device determines whether the current velocity of the particle is greater than a preset velocity threshold; if so, the velocity of the particle at the next moment is determined as the velocity threshold, and the position of the particle is updated.

[0105] Optionally, if the current velocity of the particle is less than the velocity threshold, the velocity of the particle is updated according to the following formula: velocity at time (k+1) = velocity at time k × inertia factor + velocity update factor × (global best position of phase-shifted particle swarm - position of the particle at time k).

[0106] Both the inertia factor and the speed update factor can be set by administrators in the electronic device through the aforementioned input / output interfaces.

[0107] It should be noted that when the current velocity of a particle equals a preset velocity threshold, the electronic device can determine the velocity of the particle at the next moment as the velocity threshold, or update the velocity of the particle according to the above formula. This application does not impose any limitations on this.

[0108] Optionally, the conditions for iterative convergence (end of iteration) may include: the number of iterations reaching a preset threshold, or the difference in signal-to-noise ratios corresponding to the global best positions obtained from two iterations being less than a preset error threshold.

[0109] Both the number of attempts threshold and the error threshold can be preset in the electronic device by the administrator. For example, the number of attempts threshold can be 10 or 20, and the error threshold can be 1e-5 or other values. This application embodiment does not limit the specific values ​​of the number of attempts threshold and the error threshold.

[0110] S105. The electronic device controls multiple reflective elements to reflect the signal transmitted by the base station to the user equipment according to the phase shift matrix corresponding to the optimal solution particle.

[0111] In one possible implementation, the electronic device can directly control multiple reflective elements to reflect the signal transmitted by the base station to the user equipment according to the phase shift value in the phase shift matrix corresponding to the optimal solution particle.

[0112] In another possible implementation, considering the interference between different user equipment within the coverage area of ​​the same base station, the electronic equipment can also alternately optimize the phase shift matrix corresponding to the optimal solution particle, thereby avoiding interference between user equipment.

[0113] For example, see Figure 5 , Figure 5 The diagram shows the architecture of a wireless communication system for a multi-user device assisted by a smart metasurface.

[0114] Assumption Figure 5 The base station in the system includes M antennas, and the user equipment includes K antennas, and so on. Figure 1 The situation is similar, but the interference here comes from the wireless signals transmitted by the base station to other user devices. Through analysis, we can express the signal-to-interference ratio (SIR) of user device k as:

[0115] (Base station's precoding matrix for k users × transmit power × (direct path channel + concatenated channel 1 × smart metasurface phase shift matrix × concatenated channel 2)) / (noise power + summation: base station's precoding matrix for other users × transmit power × (direct path channel + concatenated channel 1 × metasurface phase shift matrix × concatenated channel 2)))

[0116] It can be seen that the mathematical form in this case is better than the one described above. Figure 1 The situation is more complex, so a semi-definite scaling and alternating optimization solution is proposed. In this case, the above S105 can specifically include the following steps:

[0117] Step 1: Under the constraint that the received power of the first UE is greater than the power threshold, the electronic device determines the target beamforming matrix of the base station with the goal of minimizing the transmit power of the base station.

[0118] The first UE is any one of the K (or more) UEs mentioned above.

[0119] Alternatively, the electronic device may determine the target beamforming matrix of the base station according to the following formula (1):

[0120]

[0121] Where W represents the beamforming matrix of the base station. ‖w‖ 2 This represents the base station's transmit power. q represents the phase shift matrix corresponding to the optimal solution particle. h1 represents the path of the signal transmitted by the base station, reflected by the RIS according to the phase shift matrix corresponding to the optimal solution particle, to the first UE. h2 represents the direct transmission path of the signal from the base station to the first UE. γ represents the preset signal-to-interference ratio (SIR) threshold. σ 2 This represents the noise power in a wireless environment. n This represents the phase shift value of the nth reflecting element in the RIS.

[0122] Step 2: Under the constraint that the base station transmits signals according to the target beamforming matrix, the electronic device modifies the phase shift matrix corresponding to the optimal solution particle with the goal of maximizing the received power of the first UE, and obtains the modified phase shift matrix.

[0123] Alternatively, the electronic device may correct the phase shift matrix according to the following formula (2):

[0124]

[0125] Where, ‖h1+h2‖ 2 This indicates the received power of the first UE.

[0126] Since practical smart metasurface hardware structures need to satisfy a phase shift value between 0 and 2π, this constraint is equivalent to a modulus constraint, that is... Since the optimization problem is non-convex, it can be transformed into a convex optimization problem through a standard semi-definite scaling procedure. This allows it to be solved using convex optimization tools such as CVX, thereby correcting the phase shift matrix and obtaining the corrected phase shift matrix.

[0127] Step 3: Under the constraint that the received power of multiple UEs is greater than the power threshold, the electronic device performs multiple alternating corrections on the modified phase shift matrix to obtain the target phase shift matrix.

[0128] For example, the electronic device can fix the modified phase shift matrix and continue to solve the base station suspicion matrix that minimizes the base station transmit power. After multiple alternating optimizations, convergence is achieved under the constraint that the received power of multiple UEs is greater than the power threshold, and the target phase shift matrix is ​​obtained.

[0129] Step 4: The electronic device controls multiple reflective elements to reflect the signal transmitted by the base station to the UE according to the target phase shift matrix.

[0130] The signal transmission method provided in this application embodiment can use the feedback information from the user equipment as a reference to solve the phase shift matrix of the smart metasurface according to the particle swarm optimization algorithm to obtain the optimal solution particle. Based on the phase shift matrix corresponding to the optimal solution particle, the smart metasurface is controlled to reflect the signal emitted by the base station. The signal reflected to the user equipment is stronger, thereby reducing the interference of other base station signals to the user equipment. Moreover, the algorithm only needs to consider the feedback information of the user equipment, and the complexity does not increase with the increase of the number of reflection units in the smart metasurface. The phase shift matrix design is relatively simple, reducing the development difficulty.

[0131] Furthermore, to address signal interference between multiple user equipments within the coverage area of ​​the same base station, this method can also perform alternating convex optimization on these multiple user equipments to obtain a target phase shift matrix under the constraint that the received power of all multiple user equipments is greater than a power threshold. The intelligent metasurface is then controlled to reflect the base station signal according to the target phase shift matrix, resulting in stronger signal strength received by the user equipments, thereby reducing signal interference between user equipments within the coverage area of ​​the same base station.

[0132] In addition, the signal emitted by the intelligent metasurface reflective base station can refract signals that cannot be transmitted through a direct transmission path to the user equipment, thereby expanding the coverage of the base station, reducing the number of base stations to be deployed, and saving hardware costs.

[0133] The foregoing primarily describes the solutions provided by the embodiments of this application from a methodological perspective. To achieve the aforementioned functions, it includes corresponding hardware structures and / or software modules for executing each function. Those skilled in the art should readily recognize that, in conjunction with the units and algorithm steps of the various examples described in the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0134] In an exemplary embodiment, this application also provides a signal transmission device. Figure 6 This is a schematic diagram of the composition of the signal transmission device provided in the embodiments of this application, such as... Figure 6 As shown, the device may include an acquisition module 601 and a processing module 602.

[0135] The acquisition module 601 is used to acquire the phase shift matrix of the intelligent metasurface RIS; the phase shift matrix is ​​used to represent the phase shift values ​​of multiple reflective elements in the RIS; acquire the phase shift particle swarm; the phase shift particle swarm includes multiple particles; each of the multiple particles is used to represent a potential optimal solution of the RIS phase shift matrix; acquire the feedback information of the user equipment UE to each particle; the feedback information is used to represent the signal strength received by the UE.

[0136] The processing module 602 is used to iteratively search for the optimal solution particle by the phase-shifted particle swarm based on feedback information; and to control multiple reflecting elements to reflect the signal transmitted by the UE to the base station according to the phase-shift matrix corresponding to the optimal solution particle.

[0137] In some possible embodiments, for each iteration, the processing module 602 is specifically used to update the optimal position of each particle in the phase-shifted particle swarm based on the feedback information; the optimal position is the position with the highest signal-to-noise ratio between the current position and the historical position of each particle; the global optimal position of the current phase-shifted particle swarm is determined based on the optimal position of each particle; and the particle in the global optimal position is determined as the optimal solution particle.

[0138] In other possible embodiments, the processing module 602 is further configured to determine whether the current velocity of each particle in the phase-shifted particle swarm is greater than a preset velocity threshold; if so, the velocity of the particle at the next moment is determined as the velocity threshold, and the position of the particle is updated.

[0139] In some other possible embodiments, the processing module 602 is further configured to update the velocity of the particle according to the following formula if the current velocity of the particle is less than the velocity threshold: velocity at time (k+1) = velocity at time k × inertia factor + velocity update factor × (global best position of phase-shifted particle swarm - position of the particle at time k).

[0140] In some other possible embodiments, the condition for iterative convergence is: the number of iterations reaches a preset threshold, or the difference in signal-to-noise ratio corresponding to the global best position obtained by two iterations is less than a preset error threshold.

[0141] In some other possible embodiments, the UE includes multiple UEs. The processing module 602 is specifically used to determine the target beamforming matrix of the base station with the goal of minimizing the transmit power of the base station, under the constraint that the received power of the first UE is greater than a power threshold. The first UE is any one of the multiple UEs. Under the constraint that the base station transmits signals according to the target beamforming matrix, the phase shift matrix corresponding to the optimal solution particle is corrected with the goal of maximizing the received power of the first UE, to obtain the corrected phase shift matrix. Under the constraint that the received power of multiple UEs is greater than the power threshold, the corrected phase shift matrix is ​​alternately corrected multiple times to obtain the target phase shift matrix. The target phase shift matrix is ​​used to control multiple reflecting elements to reflect the signal transmitted by the base station to the UE.

[0142] In some other possible embodiments, the processing module 602 is specifically configured to determine the target beamforming matrix of the base station according to the following formula:

[0143]

[0144] Where W represents the beamforming matrix of the base station; ||w|| 2σ represents the base station's transmit power; q represents the phase shift matrix corresponding to the optimal solution particle; h1 represents the path of the signal transmitted by the base station and reflected by the RIS according to the phase shift matrix corresponding to the optimal solution particle to the first UE; h2 represents the direct path of the signal transmitted from the base station to the first UE; γ represents the preset signal-to-interference ratio threshold; σ represents the signal-to-interference ratio threshold. 2 q represents the noise power in a wireless environment. n This represents the phase shift value of the nth reflecting element in the RIS;

[0145] The phase shift matrix is ​​corrected according to the following formula:

[0146]

[0147] Where, ‖h1+h2‖ 2 This indicates the received power of the first UE.

[0148] It should be noted that, Figure 6 The module division shown is illustrative and represents only one logical functional division; in actual implementation, other division methods are possible. For example, two or more functions can be integrated into one processing module. This application does not limit this. The integrated module described above can be implemented in hardware or as a software functional module.

[0149] In an exemplary embodiment, this application also provides a readable storage medium, including: execution instructions that, when run on an electronic device, cause the electronic device to perform any of the methods provided in the above embodiments.

[0150] In an exemplary embodiment, this application also provides a computer program product containing computer execution instructions, which, when run on an electronic device, causes the electronic device to perform any of the methods provided in the above embodiments.

[0151] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software programs, implementation can be, in whole or in part, in the form of a computer program product. This computer program product includes one or more computer-executable instructions. When these computer-executable instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer-executable instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer-executable instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device containing one or more servers, data centers, etc., that can be integrated with the medium. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state disks, SSDs).

[0152] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings, disclosure, and appended claims, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple components. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0153] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of this application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from the spirit and scope of this application. Thus, if such modifications and modifications of this application fall within the scope of the claims of this application and their equivalents, this application is also intended to include such modifications and modifications.

[0154] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A signal transmission method, characterized in that, The method includes: Obtain the phase shift matrix of the intelligent metasurface RIS; the phase shift matrix is ​​used to represent the phase shift values ​​of multiple reflective elements in the RIS; Obtain a phase-shifted particle swarm; the phase-shifted particle swarm comprises multiple particles; each of the multiple particles represents a potential optimal solution to the RIS phase-shifted matrix; The user equipment (UE) receives feedback information for each particle; the feedback information is used to represent the signal strength received by the UE. Based on the feedback information, the optimal solution particle is iteratively searched for in the phase-shifted particle swarm. For each iteration, the step of iteratively searching for the optimal solution particle in the phase-shifted particle swarm based on feedback information includes: Based on the feedback information, update the optimal position of each particle in the phase-shifted particle swarm; the optimal position is the position with the highest signal-to-noise ratio between the current position and the historical position of each particle. For each particle in the phase-shifted particle swarm, determine whether the particle's current velocity is greater than a preset velocity threshold; If so, the velocity of the particle at the next moment is determined as the velocity threshold, and the position of the particle is updated; If the current velocity of the particle is less than the velocity threshold, the velocity of the particle is updated according to the following formula: velocity at time (k+1) = velocity at time k × inertia factor + velocity update factor × (global optimal position of the phase-shifted particle swarm - position of the particle at time k). Based on the optimal position of each particle, determine the global optimal position of the current phase-shifted particle swarm; and determine the particle at the global optimal position as the optimal solution particle. The multiple reflective elements are controlled to reflect the signals transmitted to the UE base station based on the phase shift matrix corresponding to the optimal solution particle.

2. The method according to claim 1, characterized in that, The conditions for iterative convergence are: the number of iterations reaches a preset threshold, or the difference in signal-to-noise ratio between the global best positions obtained from two iterations is less than a preset error threshold.

3. The method according to claim 1, characterized in that, The UE includes multiple UEs; controlling the multiple reflecting elements to reflect the signal transmitted by the base station to the UE according to the phase shift matrix corresponding to the optimal solution particle includes: Under the constraint that the received power of the first UE is greater than a power threshold, the target beamforming matrix of the base station is determined with the goal of minimizing the transmit power of the base station; the first UE is any one of a plurality of UEs; Under the constraint that the base station transmits signals according to the target beamforming matrix, with the goal of maximizing the received power of the first UE, the phase shift matrix corresponding to the optimal solution particle is corrected to obtain the corrected phase shift matrix; Under the constraint that the received power of multiple UEs is greater than the power threshold, the modified phase shift matrix is ​​modified alternately multiple times to obtain the target phase shift matrix; The target phase shift matrix is ​​used to control the multiple reflecting elements to reflect the signals transmitted by the UE to the base station.

4. The method according to claim 3, characterized in that, The step of determining the target beamforming matrix of the base station, with the objective of minimizing the transmit power of the base station, under the constraint that the received power of the first UE is greater than a power threshold, includes: The target beamforming matrix of the base station is determined according to the following formula: ； in, This represents the beamforming matrix of the base station; Indicates the base station's transmit power; This represents the phase shift matrix corresponding to the optimal solution particle; This represents the path of the signal transmitted by the base station, reflected by the RIS according to the phase shift matrix corresponding to the optimal solution particle, to the first UE; This indicates the direct path of the signal transmitted from the base station to the first UE; This indicates the preset signal-to-interference ratio (SIR) threshold. Indicates the noise power in a wireless environment; This represents the phase shift value of the nth reflecting element in the RIS; Under the constraint that the base station transmits signals according to the target beamforming matrix, and with the goal of maximizing the received power of the first UE, the phase shift matrix is ​​corrected to obtain the corrected phase shift matrix, including: The phase shift matrix is ​​corrected according to the following formula: ； in, This indicates the received power of the first UE.

5. A signal transmission device, characterized in that, The device includes: an acquisition module and a processing module; The acquisition module is used to acquire the phase shift matrix of the intelligent metasurface RIS; the phase shift matrix is ​​used to represent the phase shift values ​​of multiple reflective elements in the RIS; acquire a phase shift particle swarm; the phase shift particle swarm includes multiple particles; each of the multiple particles is used to represent a potential optimal solution of the RIS phase shift matrix; acquire feedback information of the user equipment UE to each particle; the feedback information is used to represent the signal strength received by the UE; The processing module is used to iteratively search for the optimal solution particle in the phase-shifted particle swarm based on the feedback information. For each iteration, the iterative search for the optimal solution particle in the phase-shifted particle swarm based on the feedback information includes: updating the optimal position of each particle in the phase-shifted particle swarm according to the feedback information; the optimal position is the position with the highest signal-to-noise ratio between the current position and the historical position of each particle; for each particle in the phase-shifted particle swarm, determining whether the current velocity of the particle is greater than a preset velocity threshold; if so, determining the velocity of the particle at the next moment as the velocity threshold and updating the position of the particle; if the current velocity of the particle is less than the velocity threshold, updating the velocity of the particle according to the following formula: velocity at (k+1) moment = velocity at k moment × inertia factor + velocity update factor × (global optimal position of the phase-shifted particle swarm - position of the particle at k moment); determining the current global optimal position of the phase-shifted particle swarm based on the optimal position of each particle; determining the particle at the global optimal position as the optimal solution particle; and controlling the multiple reflecting elements to reflect the signal transmitted to the UE base station according to the phase-shift matrix corresponding to the optimal solution particle.

6. An electronic device, characterized in that, The electronic device includes: a processor and a memory; The memory stores instructions that the processor can execute; When the processor is configured to execute the instructions, the electronic device performs the method as described in any one of claims 1-4.

7. A readable storage medium, characterized in that, The readable storage medium includes: software instructions; When the software instructions are executed in an electronic device, the electronic device causes the electronic device to perform the method as described in any one of claims 1-4.

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