A beam steering device for reconfigurable intelligent metasurfaces

Abstract

The present invention discloses a beam steering device for a reconfigurable intelligent metasurface, belonging to the field of beam steering. The device comprises a control module, a communication module, a power supply voltage regulator module, a driver module, a switch output module, and a wireless feedback module. An external base station platform or a host computer transmits the codebook information of the RIS beam to the communication module and the wireless feedback module, which can also receive RSRP data or target positions. The communication module and the wireless feedback module are simultaneously connected to the control module. The control module directly sends an on-off control signal to the switch output module based on instructions in the codebook information. Alternatively, the control module uses RSRP data or the target position as input to calculate the codebook information corresponding to the target beam, thereby obtaining an on-off control signal for a PIN diode and sending it in parallel to the switch output module, thereby controlling the on-off of each PIN diode to complete the beamforming of the RIS array. The present invention realizes high-speed beam steering of a reconfigurable intelligent metasurface based on a PIN diode unit structure.

Description

Technical Field

[0001] The present invention belongs to the field of beam control, and in particular relates to a beam control device for a reconfigurable intelligent metasurface. Background Art

[0002] Reconfigurable Intelligent Surface (RIS) is usually composed of a large number of carefully designed periodically arranged electromagnetic units. By configuring adjustable elements in each unit and applying control signals, each unit has the ability to independently adjust the amplitude and phase of the incident electromagnetic wave to achieve controllable propagation of electromagnetic wave reflection and transmission, thereby realizing beamforming control of the outgoing electromagnetic wave.

[0003] Most existing reconfigurable smart metasurfaces use low-cost PIN diodes to switch on and off to change the unit phase of 0 / 180°. Therefore, it is necessary to design a beam control method and device suitable for PIN diode control, and to achieve multi-bit control expansion by simply multi-channel control of multiple PIN diodes in a single unit, such as Figure 1 As shown; however, the existing control method of realizing multi-channel on-off through decoding latches has the following problems: complex system, large multi-level connection delay, poor device fault tolerance and high cost of high-precision device, which cannot meet the requirements of low cost, high-speed dynamic response and stable and reliable operation in the upgrading environment of reconfigurable intelligent metasurface industry.

[0004] The current requirements for RIS unit control based on the decoder latch drive PIN transistor are as follows:

[0005] 1. Adding many decoders, latches and other modules to the RIS unit control increases the complexity of the control network;

[0006] 2. There will be a certain delay in the decoding and latching process, which makes it difficult for the RIS response time to meet the dynamic network environment that requires high-speed adjustment;

[0007] 3. High-precision decoding and latching devices are expensive. When a large number of decoding and latching devices are required, power consumption and cost will affect the commercialization of the control device.

[0008] 4. The control system based on the decoding and latching module has poor reliability. Failure of the decoding and latching device leads to a chain reaction, causing errors in system control. Summary of the Invention

[0009] To address the above problems, the present invention proposes a beam steering device for reconfigurable intelligent metasurfaces, which realizes high-speed beam steering of reconfigurable intelligent metasurfaces based on PIN tube unit structures through the collaborative work of multiple modules.

[0010] The reconfigurable intelligent metasurface beam steering device includes a control module, a communication module, a power supply voltage stabilization module, a driving module, a switch output module and a wireless feedback module;

[0011] The external base station platform or host computer transmits the codebook information of the RIS beam to the communication module and the wireless feedback module. At the same time, the wireless feedback module can also receive RSRP data or target location. The communication module and the wireless feedback module are connected to the control module at the same time.

[0012] The control module directly sends on-off control signals to the switch output module according to the instructions in the codebook information. Alternatively, it uses RSRP data or target position as input parameters to calculate the pitch angle parameters of the corresponding target beam. The on-off control signals for the PIN diodes are then sent in parallel to the switch output module to achieve on-off control of each PIN diode to complete the beamforming of the RIS array.

[0013] The driver module controls the output of the driving voltage and current in a programmable manner to meet the driving voltage and current required by the PIN diode model, and provides a constant RIS single-channel conduction drive for the switch output module.

[0014] The reconfigurable intelligent metasurface beam steering method comprises the following specific steps:

[0015] Step 1: Turn on the power supply voltage regulator module to power each functional module in the reconfigurable intelligent metasurface beam steering device;

[0016] The positive and negative electrodes of multiple PIN diodes in the device are connected to the RIS array respectively;

[0017] Step 2: Determine the electrical parameters of the driving voltage and current required for the PIN diode to be turned on based on the PIN diode model used in the control device. The control module sends a control instruction to program the DC output of the driving module to meet the PIN diode conduction drive requirements.

[0018] Step 3: The wireless feedback module obtains codebook information or strength information RSRP from the external terminal side device and sends it to the control module;

[0019] Step 4: The control module calculates the target beam pitch angle parameter mapping based on the strength information RSRP or target position to obtain the codebook information;

[0020] According to the data obtained by the wireless feedback module, namely RSRP and target beam pitch angle parameters, there are two ways to determine the target beam codebook information:

[0021] 1) Perform beam scanning based on the RSRP of the receiving end to determine the beam codebook information;

[0022] In this process, the metasurface pre-stores the codebook information of M beams. For the current beam codebook numbered #J, the received signal strength RSRP fed back by the terminal side device J , establish a mapping table between the two, when the reconfigurable intelligent metasurface receives the signal strength RSRP J After that, switch to the beam codebook numbered #J+1 and get RSRP through feedback J+1 , establish a mapping between RSRP and codebook, and after the periodic beam scanning is completed, select the codebook with the largest RSRP as the final beam codebook information.

[0023] 2) Obtain beam codebook information based on the receiving end's position information, specifically the elevation angle parameter;

[0024] The wireless feedback module obtains the target beam pitch angle parameter. Taking the center of the metasurface as the origin, it is known that there is a point feed source at a distance d from the center of the metasurface in the vertical direction. The unit of the metasurface position coordinate (i, j) has a phase φ i,j Expressed as:

[0025]

[0026] L i,j is the distance from the feed source to position (i, j), expressed as The initial phase of the unit with the metasurface position coordinate (i, j) caused by the feed source is expressed as λ is the wavelength of the controlled electromagnetic wave; mod(·) is the remainder operation.

[0027] ΔL i,j is the ideal phase gradient of the reflected wave: ΔL i,j =x i,j sinθcosφ+y i,j sinθsinφ,x i,j and y i,j are the x- and y-coordinates of the cell in row i and column j; D x is the length of the metasurface in the x direction, D y is the length of the metasurface in the y direction (i.e., for an array size of D x ×D y of the metasurface).

[0028] θ is the pitch angle that enables the metasurface reflection to achieve the target beam; φ is the azimuth angle that enables the metasurface reflection to achieve the target beam; both angles are set artificially.

[0029] The codebook information includes the on-off state parameters of all unit PIN tubes on the metasurface array, which is a two-dimensional matrix, and the matrix elements are 0 and 1 to represent the on and off of the PIN tube;

[0030] Step 5: The communication module directly obtains the codebook information from the network side device and sends it to the control module;

[0031] Step 6: The control module determines the on / off state information of the metasurface PIN transistor according to the codebook information, and sends it to the switch output module as a parallel control signal.

[0032] The codebook information includes information received directly from the communication module, or directly received from the wireless feedback module, or obtained by RSRP calculation; or obtained by target position calculation;

[0033] Step 7: The switch output module controls the on / off state of each PIN diode on the metasurface according to the parallel control signal to complete the beamforming of the reconfigurable intelligent metasurface array.

[0034] The advantages of the present invention are:

[0035] 1) The present invention proposes a beam steering device for reconfigurable intelligent metasurfaces, which is suitable for reconfigurable intelligent metasurface beam steering based on electrically adjustable diodes. The output voltage and current of the driving module are programmable, meeting the driving requirements of PIN diodes and varactor diodes, and has the advantages of good compatibility and strong applicability.

[0036] 2) The present invention proposes a beam control device for reconfigurable intelligent metasurfaces, which uses independent switches to independently adjust the conduction and cutoff states of diodes in parallel to achieve high-speed beam switching. The control module contains a complete beam adjustment process including wireless data feedback, codebook calculation, and control instruction issuance, and has the advantages of being simple, easy to carry, and integrated. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of a control device regulating the beam switching of a reconfigurable intelligent metasurface in the prior art;

[0038] Figure 2 This is a structural diagram of a reconfigurable intelligent metasurface beam steering device according to the present invention;

[0039] Figure 3 This is an application principle diagram of a reconfigurable intelligent metasurface beam steering device of the present invention;

[0040] Figure 4 This is a schematic diagram of the autonomous beam steering structure after the program of the present invention is burned;

[0041] Figure 5 Schematic diagram of the beam steering process under external connection according to the present invention;

[0042] Figure 6 This is a schematic diagram of the autonomous beam control process after the program of the present invention is burned;

[0043] Figure 7 This is a schematic diagram of the structure of a power module in an embodiment of the present invention;

[0044] Figure 8 This is a schematic diagram of the control module structure in an embodiment of the present invention;

[0045] Figure 9 This is a schematic diagram of the communication module structure in an embodiment of the present invention;

[0046] Figure 10 This is a schematic diagram of the structure of a wireless feedback module in an embodiment of the present invention;

[0047] Figure 11 This is a schematic diagram of the driving module structure when the voltage required for PIN tube regulation is +5V in an embodiment of the present invention;

[0048] Figure 12 This is a schematic diagram of the switch output module structure when the voltage required for PIN tube regulation is +5V in an embodiment of the present invention;

[0049] Figure 13 This is a schematic diagram of the pins of the driver module in an embodiment of the present invention;

[0050] Figure 14 This is a schematic diagram of the control module pins in an embodiment of the present invention;

[0051] Figure 15 This is a schematic diagram of the pins of the power supply voltage stabilization module in an embodiment of the present invention;

[0052] Figure 16 This is a pin diagram of a wireless feedback module in an embodiment of the present invention;

[0053] Figure 17 This is a schematic diagram of the pins of the communication module in an embodiment of the present invention;

[0054] Figure 18 This is a schematic diagram of the pins of the switch output module in an embodiment of the present invention; DETAILED DESCRIPTION

[0055] The present invention will be further described in detail below with reference to the accompanying drawings and examples.

[0056] Reconfigurable Intelligent Surface (RIS) is a new type of network element, consisting of a large number of low-cost passive units (it may also be equipped with a small number of active units with transceiver functions, or all passive units can be equipped with power amplifiers). Each unit (or combination of multiple units) can independently adjust the amplitude and / or phase of the incident signal and reflect / transmit it, thus achieving beamforming.

[0057] Reference Signal Received Power (RSRP): In RIS-assisted communication networks, it represents the wireless signal strength at the receiving end.

[0058] PIN diode: An ordinary diode is composed of a PN junction. A thin layer of low-doped intrinsic semiconductor layer is added between the P and N semiconductor materials. The diode with this PIN structure is called a PIN diode.

[0059] The present invention proposes a beam steering device for reconfigurable intelligent metasurfaces. As most RIS units are based on PIN tubes to achieve phase adjustment, the beam steering device needs to have the voltage and current required for the PIN tube to conduct, as well as the output drive capability for both on and off states. It also needs to include a control module for processing the digital coding matrix for the on and off of the RIS unit, a communication module for realizing signal interaction between the modules within the control device, and a power supply voltage regulator module for voltage conversion to ensure the normal operation of the modules of the control device. Figure 2 As shown, it specifically includes a control module, a communication module, a power supply voltage regulator module, a drive module, a switch output module and a wireless feedback module; it realizes high-speed beam control of a reconfigurable intelligent metasurface based on a PIN tube unit structure.

[0060] Among them, the wireless feedback module is debugged and downloaded through physical interfaces such as Type-C in the communication module; the wireless feedback module receives RSRP or target position and codebook information and sends them to the control module, and the control module adjusts the working status of the wireless module, including WiFi on / off; the communication module connects to an external PC through JTAG and Type-C to debug and download programs to the control module (FPGA, etc.) and send codebook information; the control module controls and sends DC output voltage programming instructions, the drive module feeds back confirmation information and outputs the drive required for the PIN tube to turn on; the control module sends multi-channel parallel switch control instructions, adjusts the switch output end to connect to the DC end or the ground end, and the corresponding diode on the RIS is turned on or off, and the switch output module sends confirmation information ACK to the control module.

[0061] The network-side device or the terminal-side device transmits the target beam codebook information, RSRP, or target position information to the control module. The control module uses periodic wave sweeping based on RSRP to establish a mapping table between RSRP and codebook, determines the codebook information corresponding to the maximum RSRP, or calculates the RIS phase distribution based on the target position information, including the pitch angle parameter, and discretizes it to obtain the codebook information. It obtains the PIN tube conduction and cutoff state information instructions corresponding to the target beam and sends the on-off control signal of each PIN diode to the switch output module in parallel.

[0062] 1) The wireless feedback module is used to obtain the target beam codebook information sent by the external base station platform or the host computer to the RIS beam steering device through multiple wireless links such as WiFi, Bluetooth, Zigbee, Lora, 4G, etc.; at the same time, it obtains the RSRP data or target position information fed back to the control device by the receiving end through multiple wireless links such as WiFi, Bluetooth, Zigbee, Lora, 4G, etc. The structure is as follows Figure 10 shown.

[0063] The wireless feedback module involved in the present invention has two communication interfaces: wired and wireless. The wired method mainly realizes data interaction with the external base station and the host computer through the Micro-B interface, which is used to initialize the function test of the wireless feedback module and obtain the RIS codebook information of the external base station or the host computer; the wireless method is to establish a local area network connection (including WiFi, Bluetooth, Zigbee, Lora, 4G, etc.) to realize the acquisition of the receiving end RSRP, target location or codebook information; the wireless feedback module contains a microprocessor MCU, equipped with a complete subsystem, integrated PHY layer and MAC layer, and can support multiple wireless communication protocol connections.

[0064] 2) The communication module obtains the RIS on-off target beam codebook information required for beam control transmitted from the external base station platform or the host computer to the control device, such as Figure 4 As shown;

[0065] The communication module structure involved in the present invention is as follows Figure 9 As shown, it is used to obtain data sent by the external base station platform or the host computer in a wired manner through the communication interface. The communication interface includes a USB communication interface, a UART communication interface, an SPI serial communication interface, etc. The acquired data includes: RIS codebook information, receiving end RSRP data or target position; the communication module has a rich and expandable communication interface. In addition to the Type-C interface, Micro-B interface, JTAG interface, etc. currently used by the control device, it can also be converted into easily expandable serial communication protocols such as UART and SPI through a USB conversion chip.

[0066] 3) The control module directly sends an on-off control signal to the switch output module based on the target beam codebook information instruction output by the communication module; or uses the feedback RSRP or target position of the wireless feedback module as an input parameter to perform calculations to obtain the corresponding target beam codebook information, and then obtains the on-off control signal and sends it to the switch output module.

[0067] like Figure 8Figure 2 shows the structure of the control module of the RIS beam steering device. The control module's core control and computing components include, but are not limited to, FPGAs, microprocessors (MCUs), and CPLDs. These components provide a digital programmable operating platform, contain packaged communication protocol functions, and programmable RIS codebook information. These components also implement data processing and communication interactions with other functional modules, specifically performing the following functions:

[0068] Send parallel control signals to the switch output module to specifically regulate the on / off state of the RIS multi-channel PIN diodes; Obtain RIS control codebook information, receiving end RSRP data or target location from the wireless feedback module, and control the wireless feedback module to realize data transmission;

[0069] Realize data connection between the control module and external devices (base station platform, host computer, etc.) through serial communication and parallel communication interfaces;

[0070] Send instructions to the driver module through the serial communication interface to program the single-channel output voltage and current of the RIS control device to adapt to the conduction voltage and current of the PIN tube in the RIS to be controlled;

[0071] Establish data connection with the program burning module (including program download interface, program debugging interface, etc.) to ensure the normal operation of RIS control device initialization and subsequent instruction modification;

[0072] The intermediate data to be processed during the program running (including RIS codebook information, algorithm intermediate calculation amount, etc.) is temporarily stored in the storage module;

[0073] Obtain electrical signals from key input modules (including system reset keys, user input keys, etc.) to implement user operation command input;

[0074] The control module outputs an indication signal of a certain function working status to the status indication module (including LED, display screen, etc.), so as to facilitate the observation of the working status of each module in the control device;

[0075] 4) The switch output module uses the received on-off control signal to drive and control the on-off state of multiple PIN diodes to complete the beamforming of the RIS array.

[0076] The schematic diagram of the switch output module structure involved in the present invention is as follows Figure 12As shown, it includes multiple programmable single-pole double-throw switches. The input part of the switch is the output and ground of the driver module. The output is connected to the positive and negative terminals of the diodes in the RIS array in the form of M (M=5 in the figure) positive outputs and 1 ground, which can effectively isolate interference;

[0077] The switch output module includes a logic decoding module that can decode the control signal (0 / 1 bit sequence) from the control module in parallel to select the connection state of the switch, thereby realizing the mapping between the RIS codebook information and the on / off of the PIN tube.

[0078] According to the PIN tube conduction drive requirements, the drive module outputs a voltage of 5V, the control signal is "1001", and the logic decoding module controls the second and fourth switches to connect to the "ground" terminal and the "+5V" terminal respectively, so that the PIN-2 tube is cut off and the PIN-4 tube is turned on.

[0079] 5) The driver module controls the output of the driving voltage and current in a programmable manner to meet the driving voltage and current required by the PIN diode model, and provides a constant RIS single-channel conduction drive for the switch output module.

[0080] The driving module of the present invention is used to programmably output the voltage and current required for the PIN tube of the RIS unit to conduct. The driving module performs voltage conversion based on the +15V DC input of the power module. The reference voltage module and the voltage proportional module inside the module respectively calculate the internal reference voltage V based on the serial control signal sent by the control module. REF and output voltage ratio R OUT The value of the programmed output voltage is The DC-DC voltage conversion module outputs V OUT A DC voltage of sufficient magnitude is used to drive the subsequent PIN tube to conduct.

[0081] The drive module structure is as follows Figure 11 As shown, a special implementation example is given, in which V REF When the serial control signal is "0000000000b", the reference voltage is 45mV, and the minimum accuracy of the reference voltage adjustment is 1.129mV. When the serial control signal is "1111000000b", V REF =960×1.129+45mV=1128.84mV. When the control signal is “00”, the output voltage ratio is 0.2256. The output voltage at this time is Similar cases can be extended to other more general situations.

[0082] 6) Power supply voltage regulator module: It performs voltage regulation and conversion on the input DC voltage to provide the required DC regulated power supply for multiple different modules including the control module, wireless feedback module, drive module and switch output module.

[0083] like Figure 7 FIG2 is a schematic diagram of the structure of the power supply voltage stabilization module proposed in the present invention. The power supply module at least includes: a DC power supply module, a USB power supply module and a DC-DC voltage conversion module (including a linear regulator LDO and a switching regulator).

[0084] In the present invention, the beam steering device provides a standard +15V power supply through the DC regulated input interface of the external power supply, and the allowed input voltage range is +12~29V; there is also a USB power supply module, specifically including a Type-C input interface (+5V) and a Micro-B input interface (+5V), which is used to power the signal driver chip in the communication module; at the same time, the power supply voltage regulator module provides +12V, +5V, +3.3V, +10V and other DC power outputs. Specifically, the DC regulated input interface can output +12V, +10V, and +5V DC regulated power supplies respectively through the DC-DC voltage conversion module, and then the +5V regulated power supply is output as a +3.3V DC regulated power supply through the second DC-DC voltage conversion module.

[0085] The output power of the above power modules is used to power various functional modules in the RIS beam steering device. +15V is the power input, which powers the switch output module after filtering; +12V is used to power the control module; +10V is used as the reference voltage when the switch output module outputs a negative voltage; +5V is used to power the signal driver chip in the communication module and for +3.3V voltage conversion; +3.3V is used to power the wireless feedback module and other modules in the control device, including the status indication module (LED, etc.), push button switch, etc.

[0086] The reconfigurable intelligent metasurface beam steering method is as follows: Figure 4 The specific steps are as follows:

[0087] Step 1: Turn on the power supply voltage regulator module to power each functional module in the reconfigurable intelligent metasurface beam steering device;

[0088] The device is connected to the RIS array through a plurality of PIN diodes, or is connected to the positive and negative electrodes of the PIN diodes on the RIS array through a plurality of wires;

[0089] Step 2: According to the PIN diode model used for the reconfigurable intelligent metasurface control, the electrical parameters of the driving voltage and current required for the PIN diode to be turned on are determined, and the control module sends a driving control instruction to the driving module;

[0090] Drive control instructions include drive reference voltage, output voltage ratio, etc.

[0091] Step 3: The wireless feedback module obtains the RSRP strength information or target position from the external terminal side device. Based on the RSRP strength information, it periodically traverses the next codebook information and controls the on / off of the switch output module to obtain the receiving end RSRP under the codebook. Alternatively, the codebook information is calculated based on the phase codebook using the target position information, including the beam pitch angle parameter.

[0092] The wireless feedback module can also obtain target beam codebook information from the external terminal side device. Based on the data obtained by the wireless feedback module, namely RSRP and target beam pitch angle parameters, there are two ways to determine the target beam codebook information:

[0093] 1) The wireless feedback module performs beam scanning to find the best beam

[0094] During typical processes such as initial access and beam switching of the terminal-side device, the smart metasurface needs to perform beam scanning based on the RSRP feedback from the terminal-side device to find the optimal beam.

[0095] In this process, the metasurface pre-stores the codebook information of M beams; for the current beam numbered #J, the terminal side feeds back RSRP J Indicates the received signal strength in the case of smart metasurface beam #J. Correspondingly, a mapping table of beam number and RSRP can be established. In this case, the RSRP received by the smart metasurface can be reconstructed. J Then, the #J+1 codebook is switched, and a mapping table between RSRP and codebook is established through periodic beam scanning. The codebook information corresponding to the maximum RSRP is determined and selected as the optimal beam information.

[0096] 2) The wireless feedback module obtains the target beam pitch angle parameters;

[0097] Taking the center of the metasurface as the origin, there is a point feed at a distance d perpendicular to the center of the metasurface. The phase required by the unit at position (i, j) on the metasurface should compensate for the phase difference between the feed and the deflection path of the reflected wave. The phase φ of the unit at the position coordinate (i, j) on the metasurface is i,j Expressed as:

[0098]

[0099] L i,j is the distance from the feed source to position (i, j), expressed as The initial phase of the unit with the metasurface position coordinate (i, j) caused by the feed source is expressed as λ is the wavelength of the controlled electromagnetic wave.

[0100] ΔLi,j is the ideal phase gradient of the reflected wave: ΔL i,j =x i,j sinθcosφ+y i,j sinθsinφ, and are the x- and y-coordinates of the cell in row i and column j; the cell spacing in the x- and y-directions of the metasurface is d x and d y , the metasurface array size is D x ×D y , then the number of units in the x-direction and y-direction is and θ is the pitch angle that enables the metasurface reflection to achieve the target beam; φ is the azimuth angle that enables the metasurface reflection to achieve the target beam; both angles are set artificially.

[0101] The target beam codebook information includes the on-off state parameters of all unit PIN tubes on the metasurface array;

[0102] Step 4: The communication module directly obtains the target beam codebook information from the network side device and sends it to the control module;

[0103] Step 5: The control module determines the on / off state information of the metasurface PIN tube according to the target beam codebook information, and sends the on / off state control information as a parallel control signal to the switch output module.

[0104] Step 6: The switch output module controls the on / off state of each PIN diode on the metasurface according to the parallel control signal to complete the beamforming of the reconfigurable intelligent metasurface array.

[0105] Furthermore, the present invention determines whether the target beam codebook information needs to be calculated by the control module. The data interaction between the functional modules mainly includes the following two types:

[0106] (1) The control module calculates and obtains the target beam codebook information. The process is as follows: Figure 5 As shown;

[0107] Step 1: According to the PIN diode model used for the reconfigurable intelligent metasurface control, the electrical parameters of the driving voltage and current required for the PIN diode to be turned on are determined, and the control module sends a driving control instruction to the driving module;

[0108] Step 2: The wireless feedback module obtains RSRP or target position from the external terminal side device and sends it to the control module;

[0109] Step 3: The control module obtains the target beam codebook information through periodic wave scanning or calculation according to the RSRP of the terminal side device or the pitch angle parameter of the target position;

[0110] Step 4: The control module determines the on / off state information of the metasurface PIN tube according to the target beam codebook information, and sends the on / off state control information to the switch output module.

[0111] (2) The communication module directly obtains the target beam codebook information;

[0112] Step 1: According to the PIN diode model used for the reconfigurable intelligent metasurface control, the electrical parameters of the driving voltage and current required for the PIN diode to be turned on are determined, and the control module sends a driving control instruction to the driving module;

[0113] Step 2: The communication module or the wireless feedback module obtains the target beam codebook information from the network side device and sends it to the control module;

[0114] Step 3: The control module determines the on / off state information of the metasurface PIN tube according to the target beam codebook information, and sends the on / off state control information to the switch output module.

[0115] The RIS beam control device of the present invention has two working modes: beam control under external connection and autonomous beam control after program burning. The specific beam control process is as follows: Figure 5 and Figure 6 As shown:

[0116] 1. The data transmission process in the external connection state is as follows Figure 3 As shown, the codebook information required for regulation can be sent directly to the wireless feedback module or the communication module via a wired manner; RSRP data can also be sent to the control module via a wired manner;

[0117] 2. The data transmission process after program burning is as follows Figure 4 As shown, the control device has no wired connection with the outside world and only obtains RSRP data or target position or codebook information through the wireless feedback module;

[0118] Specifically:

[0119] Beam steering working mode under external connection: Applicable to when the codebook operation module in the control module fails to work normally, the base station platform or the host computer runs the codebook information algorithm, and connects the output RIS beam codebook information to the wireless feedback module via wireless or wired means, or connects it to the communication module via wired means. The control module first sends a drive control signal to the drive module according to the voltage and current required for the PIN tube to turn on, and then controls the on-off of a specific switch output according to the obtained codebook information.

[0120] Autonomous beam steering mode after program burning: This mode allows the control device to autonomously implement beam steering based on the received signal reference power (RSRP) or target position at the receiving end. The receiving end wirelessly transmits the RSRP or target position to the feedback module. The codebook operation module in the control module uses the RSRP information or target position as input to calculate the corresponding on-off control information, specifically controlling the on / off of a certain path in the switch output module.

[0121] Example:

[0122] An embodiment is expanded below to illustrate the pin connection characteristics of each module.

[0123] 1) Driver module

[0124] The pin functions and logical connections of the driver module involved in the present invention are as follows: Figure 13 As shown:

[0125] 15V power pin: The DC power input of the RIS control device is connected to the 15V power pin after filtering and other circuits to provide a stable constant voltage power supply for the control device;

[0126] Enable pin: used to enable or disable the driver module;

[0127] Serial signal pin: exchanges data with the control module through serial communication protocol. 2 Taking C as an example, it includes two physical interfaces, SCL (clock line) and SDA (data line) pulled up by +3.3V, which reads the bit sequence of the control module and determines the ratio of the reference voltage to the output voltage.

[0128] Voltage feedback pin: outputs the reference voltage of the driving module to verify the accuracy of reference voltage regulation;

[0129] Output pin: outputs the voltage and current determined by the control module through serial communication signals;

[0130] 2) Control module

[0131] The control module of the present invention includes the pin functions and logic connections as follows Figure 14 As shown:

[0132] 12V power supply pin: The 12V DC output of the power regulator module supplies power to the control module;

[0133] Status indication pin: used to control status indicator devices (LED, display, etc.) to display working status;

[0134] Signal pins 1 to N (N depends on the type of computing device used): connect to the wireless feedback module, drive module, switch output module and other devices to send control signals and exchange data. The switch output module uses parallel signals, and the high-speed PIN tube is turned on and off to achieve fast beam switching.

[0135] Human-computer interaction pin: The input electrical signal of the user input button and other devices is connected to the control module;

[0136] 3) Power supply voltage regulator module

[0137] The power supply voltage stabilizing module of the present invention includes the pin functions and logic connections as shown in FIG. Figure 15 As shown:

[0138] 15V input pin: DC power input of RIS control device;

[0139] Protection circuit pin: connected to protection devices such as rectifier diodes to achieve overvoltage, overcurrent, reverse connection, surge protection, and avoid overload and short circuit;

[0140] Filter circuit pin: connected to the filter capacitor and resistor related circuits to ensure the stability of the DC circuit and reduce irregular waveforms and noise in the AC circuit;

[0141] 12V, 10V, 5V, and 3.3V output pins: The power supply voltage regulator module is based on a 15V DC input, and outputs from the above pins after DC-DC conversion. It also serves as the power supply for the control module, output reference voltage, wireless feedback module, and other parts of the RIS control device;

[0142] 4) Wireless feedback module

[0143] The wireless feedback module of the present invention includes the following pin functions and logical connections: Figure 16 As shown:

[0144] 3.3V input pin: connected to the "3.3V output pin" of the power regulator module to power the wireless feedback module;

[0145] USB input pin: connected to the Micro-B pin of the communication module to realize wireless feedback module initialization, program update and host computer data interaction;

[0146] Wireless pin: Through wireless connection methods such as WiFi, Bluetooth, 4G, etc., data is exchanged with network elements in the same local area network. The RIS control device communicates with the external base station platform, host computer, and receiving end;

[0147] Serial signal pin: connected to the signal pin of the control module to enable the control module to read and process data from the wireless feedback module;

[0148] 5) Communication module

[0149] The communication module of the present invention includes the pin functions and logical connections as shown in FIG. Figure 17 As shown:

[0150] 5V power pin: Connect to the "5V output pin" of the power regulator module, or connect to the USB 5V power interface for power supply;

[0151] 3.3V power pin: Connect to the "3.3V output pin" of the power regulator module to achieve stable power supply for JTAG program burning;

[0152] Serial signal pins 1 / 2: connected to the signal pins of the control module, wireless feedback module, etc. to realize internal data interaction of the control device;

[0153] Serial signal pin 3: connected to the communication pin of the external base station platform and host computer to realize the download and debugging of the program running on the control device;

[0154] 6) Switch output module

[0155] The switch output module of the present invention includes the pin functions and logic connections as follows Figure 18 As shown:

[0156] 15V power supply pin: connected to the 15V DC input of the control device to provide a stable constant voltage power supply for the switching output device;

[0157] Parallel signal pin: connected to the parallel signal pin of the control module to realize independent control of the single-pole double-throw switch state by the control signal;

[0158] Positive input pin: The output pin of the driver module is connected to the 1 terminal of multiple switches;

[0159] Negative input pin: Commonly connected to terminal 2 of the control device;

[0160] Independent output pin: The COM terminal of the switch is connected to the positive terminal of the PIN tube on the RIS unit;

[0161] The RIS beam steering device of the present invention is not only suitable for 1-bit intelligent metasurface beam steering, but also for metasurface multi-bit beam steering based on electrically adjustable diodes. The number of metasurface units is M, and each unit contains n diodes, that is, the highest n-bit phase control requires n*M diodes. Therefore, the switch output module in the beam steering device of the present invention controls the on-off state of n*M diodes through n*M parallel control lines.

Claims

1. A beam steering device for a reconfigurable intelligent metasurface, characterized in that: Specifically include: Control module, communication module, power supply voltage regulator module, drive module, switch output module and wireless feedback module; The external base station platform or host computer transmits the codebook information of the RIS beam to the communication module and the wireless feedback module. At the same time, the wireless feedback module can also receive RSRP data and target location information. The communication module and the wireless feedback module are connected to the control module at the same time. The control module directly sends on-off control signals to the switch output module based on the instructions in the codebook information transmitted by the wireless feedback module and the communication module. Alternatively, the control module uses the RSRP data or target position information received by the wireless feedback module as input parameters to perform calculations to obtain the control codebook information corresponding to the target beam. The control signals for the PIN diodes are then sent in parallel to the switch output module to achieve on-off control of each PIN diode, thereby completing the beamforming of the RIS array. The RSRP data is the received signal strength information fed back by the receiving end, and the target position information includes the target pitch angle parameter; The switch output module structure includes multiple programmable single-pole double-throw switches. The input part of the switch is the output of the driver module and the ground. The output is connected to the positive and negative terminals of the diodes in the RIS array in the form of M positive outputs and 1 ground. The switch output module includes a logic decoding module, which decodes the control signal from the control module, that is, the 0 / 1 bit sequence, in parallel to select the connection state of the switch, realizing the mapping between the RIS codebook information and the on / off of the PIN tube; Depending on whether the codebook operation module of the control module is working properly, the beam steering is divided into two working modes: beam steering under external connection and autonomous beam steering after program burning; Beam steering under external connection includes the following situations: the codebook operation module of the control module cannot work normally, and the initialization, installation and debugging process of the RIS beam steering device; When the codebook operation module in the control module fails to work properly, the beam steering working mode under external connection is adopted; when the codebook operation module in the control module can work properly, the autonomous beam steering working mode after program burning is adopted; The reconfigurable intelligent metasurface beam steering method using the beam steering device comprises the following specific steps: Step 1: The power supply voltage regulator module works normally to supply power to each functional module in the reconfigurable intelligent metasurface beam steering device; Step 2: Determine the electrical parameters of the driving voltage and current required for the PIN diode to be turned on based on the PIN diode model used in the control device; the control module programs and controls the output of the driving module to meet the driving requirements of the PIN diode; Step 3: The wireless feedback module obtains codebook information or strength information RSRP or location information from the external base station platform or host computer and sends it to the control module; Step 4: The control module uses the strength information RSRP to periodically traverse the next codebook information and adjust the switch output module to obtain the receiving end RSRP under the codebook; Alternatively, the codebook information is obtained by calculating the target position information, including the beam pitch angle parameters, according to the phase codebook; The codebook information includes the on-off state parameters of all unit PIN tubes on the metasurface array, which is a two-dimensional matrix, and the matrix elements are 0 and 1 to represent the on and off of the PIN tube; Step 5: The communication module directly obtains the codebook information from the external base station platform or the host computer and sends it to the control module; Step 6: The control module determines the on / off state information of the metasurface PIN transistor according to the codebook information and sends it to the switch output module as a parallel control signal; Step 7: The switch output module controls the on / off state of each PIN diode on the metasurface according to the parallel control signal to complete the beamforming of the reconfigurable intelligent metasurface array.

2. The beam steering device according to claim 1, wherein: The driving module controls the output of driving voltage and current in a programmable manner to meet the driving voltage and current required by the PIN diode model, and provides a constant RIS single-channel conduction drive for the switch output module.

3. The beam steering device according to claim 1, wherein: The power supply voltage stabilization module performs voltage stabilization conversion on the input DC voltage, and is used to provide the required DC regulated power supply for multiple different modules including the control module, the wireless feedback module, the drive module and the switch output module.

4. The beam steering device according to claim 1, wherein: The wireless feedback module has two communication interfaces, wired and wireless. The wired interface realizes data interaction with the external base station and the host computer, which is used to initialize the function test of the wireless feedback module and obtain the RIS code book information of the external base station or the host computer; the wireless interface is connected through a local area network to realize the acquisition of RSRP, location information sent wirelessly by the receiving end, or RIS code book information sent wirelessly by the external base station / host computer.

5. The beam steering device according to claim 1, wherein: When the codebook operation module in the control module fails to work properly, the beam steering working mode under the external connection is adopted, specifically: The base station platform or host computer runs the codebook information algorithm and connects the output RIS beam codebook information to the wireless feedback module or communication module via wireless or wired means. The control module first sends a drive control signal to the drive module based on the voltage and current required for the PIN tube to conduct. Then, the specific switch output is turned on and off according to the acquired codebook information. When the codebook operation module in the control module can work normally, the autonomous beam steering working mode after program burning is adopted, specifically: The receiving end sends RSRP data or location information to the wireless feedback module wirelessly. The codebook operation module in the control module receives the RSRP data or location information as input, calculates the corresponding on-off control information, and specifically regulates the on-off of a certain path of the switch output module.

6. The beam steering device according to claim 1, wherein: In the step 1, the positive and negative electrodes of the plurality of PIN diodes in the device are connected to the RIS array respectively.

7. The beam steering device according to claim 1, wherein: In step 4, the wireless feedback module obtains RSRP and performs beam scanning to find the best beam. During this process, the metasurface pre-stores codebook information of M beams. For the current beam codebook number #J, the received signal strength RSRP fed back by the terminal side device J , establish a mapping table between the two, when the reconfigurable intelligent metasurface receives the signal strength RSRP J After that, the beam codebook numbered #J+1 is switched, and the beam codebook corresponding to the largest received signal strength RSRP in the mapping table is selected as the optimal beam.

8. The beam steering device according to claim 1, wherein: In step 4, the wireless feedback module obtains the target position information, that is, in the beam pitch angle parameter, with the center of the metasurface as the origin, there is a point feed source at a distance d from the center of the metasurface in the vertical direction, and the metasurface position coordinates are (i, j) units, and their phase φ i,j Expressed as: L i,j is the distance from the feed source to position (i, j), expressed as The initial phase of the unit with the metasurface position coordinate (i, j) caused by the feed source is expressed as λ is the wavelength of the controlled electromagnetic wave; ΔL i,j is the ideal phase gradient of the reflected wave: ΔL i,j =x i,j sinθcosφ+y i,j sinθsinφ,x i,j and y i,j are the x- and y-coordinates of the cell in row i and column j; The unit spacing of the metasurface in the x and y directions is d x and d y , D x is the length of the metasurface in the x direction, D y is the length of the metasurface in the y direction; θ is the pitch angle that enables the metasurface reflection to achieve the target beam; φ is the azimuth angle that enables the metasurface reflection to achieve the target beam; these two angles are set artificially.

9. The beam steering device according to claim 1, wherein: In step 6, the codebook information includes being received directly from the communication module, or being received directly from the wireless feedback module, or being obtained by traversing the next codebook in the pre-stored codebook library according to the received RSRP, or being obtained by performing codebook calculation on the received target position information.

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