Smart reflector assisted millimeter wave communication link enhancement method and system

Abstract

The present application relates to the technical field of wireless communication, and specifically relates to a smart reflecting surface assisted millimeter wave communication link enhancement method and system, steps comprising obtaining strain, temperature data of a flexible smart reflecting surface, terminal attitude and channel data; generating a three-dimensional curved surface equation of the flexible smart reflecting surface by using a curved surface reconstruction model, calculating a thermal dielectric phase offset; predicting terminal coordinates and calculating a physical geometric phase deviation amount in combination with the curved surface equation; generating a total phase distortion matrix by vector superposition; solving a reverse phase compensation matrix when signal-to-noise ratio attenuation or phase mismatch exceeds a standard, searching for a voltage mapping table to generate a bias voltage instruction to drive each array element to complete phase adjustment. The present application simultaneously compensates for phase distortion caused by deformation of the reflecting surface, temperature drift and terminal motion, and enhances millimeter wave communication link quality.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and more specifically to a method and system for enhancing millimeter-wave communication links with intelligent reflector assistance. Background Technology

[0002] The combination of intelligent reflectors (RIS) and millimeter-wave (mmWave) communication is a significant development trend in the field of wireless communication. With the evolution of 5G and 6G communication technologies, millimeter waves, due to their high bandwidth and high speed, are widely used in high-capacity data transmission scenarios. However, millimeter-wave signals have extremely short wavelengths, suffer severe spatial attenuation, and are easily blocked by buildings. To overcome the poor penetration and coverage blind spots of millimeter-wave signals, intelligent reflectors (RIS) composed of numerous low-cost passive / semi-active metamaterial units have become a key technology for enhancing the coverage and signal quality of millimeter-wave communication links. By adaptively adjusting the phase and amplitude of the reflecting units, they can achieve directional reconfiguration and dynamic bending of the electromagnetic beam.

[0003] In practical engineering deployments, to reduce installation costs and maintain building aesthetics, existing technologies typically attach flexible thin-film Reflective Arrays (RIS) to the glass curtain walls or exterior surfaces of high-rise buildings, assuming the RIS is in an ideal static two-dimensional planar state. Under this assumption, existing beamforming and phase control algorithms use a fixed geometric coordinate system to solve for the array response vector of the reflective elements, effectively compensating for free-space transmission loss and improving signal strength at the receiver. However, in real high-altitude canyons or high-rise building exteriors, flexible RIS inevitably suffers from the mechanical pushing of high-altitude wind loads and the non-uniform thermal stress generated by direct sunlight, causing non-three-dimensional micron-level surface bending and deformation of the RIS physical structure. Simultaneously, sudden changes in the high-altitude wind field can trigger instantaneous displacement and attitude drift of the airborne receiver. Because existing technologies rely on a fixed two-dimensional planar physical model, they cannot sense and respond to the dynamic surface deformation of the RIS structure itself. Even minor structural bending can cause a significant shift in the spatial optical path difference of the reflected beam, leading to coherent interference failure between array elements and beam divergence, resulting in a drastic decrease or even interruption of the millimeter-wave communication link's communication quality.

[0004] Therefore, a technical solution is urgently needed to solve the problems mentioned above. Summary of the Invention

[0005] In view of the above-mentioned shortcomings of the prior art, the present invention provides a method and system for enhancing millimeter-wave communication links with intelligent reflective surface assistance, which can effectively solve the problems mentioned in the prior art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides a method for enhancing millimeter-wave communication links with intelligent reflector assistance, the specific steps of which include:

[0008] S100: Acquire strain data reported by the strain sensor array deployed on the back of the flexible smart reflective surface, temperature data reported by the temperature sensor array, and attitude motion data and link channel status data reported by the mobile terminal through the wireless channel.

[0009] S200. Based on the strain data, generate the three-dimensional spatial coordinate surface equation of the flexible intelligent reflective surface using a preset surface reconstruction model.

[0010] S300. Input the temperature data into a preset electromagnetic-temperature mapping relationship and calculate the thermal dielectric phase offset of each reflective element in the flexible intelligent reflective surface.

[0011] S400. Predict the spatial position coordinates of the mobile terminal based on the attitude motion data, and calculate the physical geometric phase deviation of each reflection element relative to the base station and the mobile terminal by combining the three-dimensional spatial coordinate surface equation.

[0012] S500: Vector superposition of the thermal dielectric phase offset and the physical geometric phase deviation to generate a total phase distortion matrix;

[0013] S600. Calculate the real-time signal-to-noise ratio prediction based on the link channel status data;

[0014] S700. When the real-time signal-to-noise ratio estimate is less than a preset communication quality threshold, or the maximum offset in the total phase distortion matrix is ​​greater than a preset phase tolerance threshold, the reverse phase compensation matrix is ​​solved based on the total phase distortion matrix and the target focusing phase.

[0015] S800: Based on the reverse phase compensation matrix, look up the preset voltage mapping table, generate a bias voltage control command, and send the bias voltage control command to the control chip of the flexible intelligent reflective surface to drive each reflective array element to complete phase adjustment.

[0016] Furthermore, the step of generating the three-dimensional spatial coordinate surface equation of the flexible intelligent reflective surface using a preset surface reconstruction model based on the strain data includes:

[0017] The strain data is analyzed to obtain the strain tensor along the principal axis of the flexible smart reflective surface, and the strain tensor is substituted into the following formula to calculate the normal curvature of the flexible smart reflective surface at each sampling node:

[0018] ;

[0019] in, For nodes Normal curvature at that point; and They are nodes The strain tensor values ​​in the X and Y axis directions; The Poisson's ratio of the substrate material of the flexible intelligent reflective surface; The thickness of the substrate structure of the flexible intelligent reflective surface;

[0020] Based on the normal curvature at each sampling node, a quadratic surface fitting is performed to obtain the equation of the three-dimensional spatial coordinate surface. .

[0021] Furthermore, the step of predicting the spatial position coordinates of the mobile terminal based on the attitude motion data, and calculating the physical geometric phase deviation of each reflection array element relative to the base station and the mobile terminal by combining the three-dimensional spatial coordinate surface equation, includes:

[0022] The three-axis acceleration and three-axis angular velocity are extracted from the attitude motion data, and the three-dimensional spatial predicted coordinates of the mobile terminal in the next time slot are predicted using a preset Kalman filter algorithm.

[0023] Calculate the actual three-dimensional physical coordinates of each reflection element under the equation of the three-dimensional spatial coordinate surface;

[0024] Based on the actual three-dimensional physical coordinates, the preset three-dimensional coordinates of the base station, and the predicted three-dimensional spatial coordinates, the spatial optical path difference of the beam transmission is solved, and the physical geometric phase deviation corresponding to each reflector element is calculated based on the spatial optical path difference.

[0025] Furthermore, the step of solving for the spatial optical path difference of the beam transmission and calculating the physical geometric phase deviation corresponding to each reflection element based on the spatial optical path difference includes:

[0026] The spatial geometric phase deviation of the (m,n)th reflection element relative to the ideal planar state is calculated using the following formula. :

[0027]

[0028] ;

[0029] in, The operating wavelength for millimeter waves; The actual three-dimensional physical coordinates of the (m,n)th reflection element; The three-dimensional coordinates of the base station; Predict coordinates for the three-dimensional space; It is the sum of the spatial distances from the (m,n)th reflection element to the base station and the mobile terminal under the assumption of an ideal two-dimensional plane.

[0030] Furthermore, the step of inputting the temperature data into a preset electromagnetic-temperature mapping relationship and calculating the thermal dielectric phase shift of each reflective element in the flexible intelligent reflective surface includes:

[0031] Extract the real-time temperature value corresponding to each reflective element from the temperature data, substitute the real-time temperature value into the preset dielectric constant temperature drift function, and determine the microstrip line equivalent dielectric constant of each reflective element at the current moment.

[0032] The change in propagation constant of the microstrip line is calculated based on the equivalent dielectric constant of the microstrip line, and the change in propagation constant is multiplied by the physical length of the microstrip line of the array element to obtain the thermal dielectric phase offset of the corresponding reflective array element.

[0033] Furthermore, the step of looking up a preset voltage mapping table based on the reverse phase compensation matrix to generate a bias voltage control command includes:

[0034] The target adjustment phase value of the (m,n)th reflection element is calculated using the following formula. :

[0035] ;

[0036] in, For the ideal alignment state, the first The desired beamforming phase required for each reflection element; For the first The thermal dielectric phase offset of each reflective element; For the first The physical geometric phase deviation of each reflection element;

[0037] Adjust the phase value of the target To carry out For periodic phase mapping, obtain the state at... Target phase adjustment within the interval ;

[0038] Adjust the phase according to the target. Match the corresponding bias voltage value in the voltage mapping table and encapsulate it into the bias voltage control instruction.

[0039] Furthermore, after driving each reflective array element to complete phase adjustment, the process also includes:

[0040] Obtain the updated channel status data for the current transmission cycle after adjustment;

[0041] Based on the updated channel state data, determine whether the signal-to-noise ratio improvement is greater than a preset gain threshold;

[0042] If the signal-to-noise ratio improvement is less than or equal to the gain threshold, a local pilot scan procedure is triggered to fine-tune the voltage amplitude in the bias voltage control command.

[0043] A smart reflector-assisted millimeter-wave communication link enhancement system includes:

[0044] The data acquisition module is used to acquire strain data reported by the strain sensor array deployed on the back of the flexible smart reflective surface, temperature data reported by the temperature sensor array, and attitude motion data and link channel status data reported by the mobile terminal through the wireless channel.

[0045] The surface reconstruction module is used to generate the three-dimensional spatial coordinate surface equation of the flexible intelligent reflective surface based on the strain data and using a preset surface reconstruction model.

[0046] The temperature drift calculation module is used to input the temperature data into a preset electromagnetic-temperature mapping relationship and calculate the thermal dielectric phase shift of each reflective element in the flexible intelligent reflective surface.

[0047] The geometric deviation calculation module is used to predict the spatial position coordinates of the mobile terminal based on the attitude motion data, and calculate the physical geometric phase deviation of each reflection array element relative to the base station and the mobile terminal by combining the three-dimensional spatial coordinate surface equation.

[0048] The phase fusion module is used to vector-superimpose the thermal dielectric phase offset and the physical geometric phase deviation to generate a total phase distortion matrix.

[0049] The channel evaluation module is used to calculate the real-time signal-to-noise ratio prediction based on the link channel state data;

[0050] The control decision module is used to solve the inverse phase compensation matrix based on the total phase distortion matrix and the target focusing phase when the real-time signal-to-noise ratio prediction is less than a preset communication quality threshold, or the maximum offset in the total phase distortion matrix is ​​greater than a preset phase tolerance threshold.

[0051] The drive control module is used to look up a preset voltage mapping table according to the reverse phase compensation matrix, generate a bias voltage control command, and send the bias voltage control command to the control chip of the flexible intelligent reflective surface to drive each reflective array element to complete phase adjustment.

[0052] Furthermore, the system also includes a flexible printed circuit board deployed on the back of the flexible smart reflective surface, on which the strain sensor array and the temperature sensor array are integrated;

[0053] The strain sensor array includes multiple miniature piezoresistive strain gauges uniformly distributed in a grid pattern;

[0054] The temperature sensor array includes multiple thermistor sensing units attached in multiple regions.

[0055] Furthermore, the control chip includes a multi-channel digital-to-analog converter and a voltage drive amplification interface that is electrically connected to the varactor diode array of the flexible smart reflective surface in a one-to-one correspondence, for converting the bias voltage control command into a continuously changing analog voltage applied to the corresponding varactor diodes.

[0056] The technical solution provided by this invention has the following advantages compared with the known prior art:

[0057] This invention reconstructs the three-dimensional surface equations and temperature drift phase of the RIS in real time through a sensing grid integrated on the back, and solves the real spatial optical path difference by combining terminal attitude prediction. This achieves adaptive reverse correction of structural deformation and environmental temperature drift, significantly reducing the impact of harsh high-altitude physical fields on millimeter-wave communication, ensuring precise beam focusing, and avoiding frequent link interruptions.

[0058] This invention unifies and abstracts three different dimensions of physical changes in the RIS itself—structural bending, thermal dielectric drift, and terminal spatial position drift—into a nonlinear phase distortion data stream along the spatial transmission path, and uses a cohesive electromagnetic-physical mapping model for collaborative solution. Simultaneously, the final calculated excess phase is precisely mapped to the adjustable control range of the diode, achieving both "structural surface compensation" and "dynamic terminal trajectory tracking" with minimal hardware tuning overhead. This significantly improves the system's adaptive response speed and engineering feasibility in complex dynamic scenarios. Attached Figure Description

[0059] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0060] Figure 1 This is a schematic diagram of the method flow of the present invention;

[0061] Figure 2 This is a schematic diagram of the system structure of the present invention. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0063] The present invention will be further described below with reference to embodiments.

[0064] Example:

[0065] Reference Figure 1 The method for enhancing millimeter-wave communication links with intelligent reflector-assisted methods includes the following steps:

[0066] S100: Acquire strain data reported by the strain sensor array deployed on the back of the flexible smart reflective surface, temperature data reported by the temperature sensor array, and attitude motion data and link channel status data reported by the mobile terminal through the wireless channel.

[0067] In this step, strain data is collected and reported by miniature piezoresistive strain gauges on a flexible printed circuit board at a preset sampling period; temperature data is collected and reported synchronously by a thermistor sensing unit; attitude motion data is generated by the inertial measurement unit built into the mobile terminal, including triaxial acceleration and triaxial angular velocity; link channel status data is reported by the mobile terminal after channel estimation based on pilot signals sent by the base station, and includes at least channel gain, noise power spectral density, and time delay and angle information of each path, which are used for subsequent calculation of real-time signal-to-noise ratio prediction.

[0068] S200. Based on the strain data, the three-dimensional spatial coordinate surface equation of the flexible intelligent reflective surface is generated using a preset surface reconstruction model.

[0069] The core of this step is to reconstruct the strain measurements at discrete points on the back of the flexible intelligent reflective surface into a continuous three-dimensional spatial coordinate surface equation to accurately describe the actual spatial position of each reflective element.

[0070] First, the strain tensor along the principal axis of the flexible intelligent reflector is obtained by analyzing the strain data. Since miniature piezoresistive strain gauges are arranged in a grid pattern on the back of the flexible intelligent reflector, and two sets of strain gauges in orthogonal directions are arranged at each sampling node, the strain tensor values ​​in the X-axis and Y-axis directions of the sampling node are read respectively. and .

[0071] Subsequently, the strain tensor is substituted into the following formula to calculate the normal curvature of the flexible smart reflector at each sampling node:

[0072] ;

[0073] in, For nodes Normal curvature at that point; and They are nodes The strain tensor values ​​in the X and Y axis directions; Poisson's ratio for the substrate material of flexible intelligent reflective surfaces; The thickness of the substrate structure of the flexible intelligent reflective surface; the Poisson's ratio and the substrate structure thickness are obtained through material parameter calibration before system deployment and stored as constants in the surface reconstruction module.

[0074] After obtaining the normal curvature at each sampling node, a quadratic surface fitting is performed based on the normal curvature at each sampling node to obtain the three-dimensional spatial coordinate surface equation Z=f(X,Y). Specifically, let the expression of the three-dimensional spatial coordinate surface equation be:

[0075] ;

[0076] Where a, b, c, d, e, and f are the surface coefficients to be determined. The coordinates at each sampling node are used... and its normal curvature By combining the first and second derivative relationships of the surface equation, an overdetermined linear equation system with respect to the aforementioned coefficients is established. Solving this system using the least squares method determines the coefficients a, b, c, d, e, and f, thus yielding the complete three-dimensional spatial coordinate surface equation Z=f(X,Y). This surface equation is then used in subsequent steps to calculate the actual three-dimensional physical coordinates of each reflection array element.

[0077] S300: Input the temperature data into the preset electromagnetic-temperature mapping relationship and calculate the thermal dielectric phase offset of each reflective element in the flexible intelligent reflective surface.

[0078] During operation, the dielectric constant of the substrate material in a flexible smart reflective surface may drift due to changes in ambient temperature or power dissipation of millimeter-wave signals. This drift can alter the propagation constant of the microstrip line, ultimately resulting in a phase shift in each reflective element. This step aims to quantitatively compensate for temperature-induced phase shifts.

[0079] First, the real-time temperature value T(m,n) corresponding to each reflector element is extracted from the temperature data. Substituting the real-time temperature value into the preset dielectric constant temperature drift function, the equivalent dielectric constant of the microstrip line for each reflector element at the current moment is determined. The dielectric constant temperature drift function adopts the following linear approximation model:

[0080] ;

[0081] in, The equivalent dielectric constant of the microstrip line at real-time temperature T; Reference temperature The equivalent dielectric constant of the microstrip line is shown below. The temperature drift coefficient of the equivalent dielectric constant of the flexible intelligent reflective surface substrate material was obtained through a temperature chamber calibration experiment before system deployment.

[0082] Subsequently, the change in the propagation constant of the microstrip line is calculated based on the equivalent dielectric constant. The relationship between the propagation constant β and the equivalent dielectric constant of the microstrip line is as follows: ,in, For millimeter wave operating frequency, Equivalent permeability Let be the speed of light in a vacuum. Substituting the equivalent dielectric constant after the temperature change into the equation and subtracting it from the propagation constant at the reference temperature, we can obtain the change in the propagation constant. Multiplying the change in propagation constant by the physical length L of the microstrip line of the array element yields the thermal dielectric phase shift of the corresponding reflective array element. Perform the above calculations on all reflective elements to obtain the thermal dielectric phase offset matrix.

[0083] S400: Predict the spatial position coordinates of the mobile terminal based on the attitude motion data, and calculate the physical geometric phase deviation of each reflection element relative to the base station and the mobile terminal by combining the three-dimensional spatial coordinate surface equation.

[0084] Because mobile terminals undergo attitude movement during communication, their spatial position changes over time. To ensure that the beam is always accurately aligned with the mobile terminal, it is necessary to predict the position of the next time slot and calculate the physical geometric phase deviation introduced by the deformation of the flexible intelligent reflector surface and the change in the position of the mobile terminal.

[0085] First, the triaxial acceleration and triaxial angular velocity are extracted from the attitude motion data, and a pre-defined Kalman filter algorithm is used to predict the three-dimensional spatial coordinates of the mobile terminal in the next time slot. Specifically, the state vector of the Kalman filter is established:

[0086] ;

[0087] in, Let k be the three-dimensional position coordinates of the mobile terminal at time k; For three-dimensional velocity; This represents the three-axis acceleration bias. The observation vector is constructed from the three-axis acceleration and three-axis angular velocity in the attitude motion data after coordinate transformation. The kinematic equations of the mobile terminal are described by the state transition matrix, and the mapping relationship between attitude motion data and state vectors is established by the observation matrix. By sequentially performing prediction updates and measurement updates, the predicted three-dimensional spatial coordinates of the mobile terminal in the next time slot can be output. .

[0088] Next, the actual three-dimensional physical coordinates of each reflection element under the three-dimensional spatial coordinate surface equation are calculated. For the (m,n)th reflection element, its two-dimensional coordinates in the flexible intelligent reflective surface planar mesh are... Substituting the equation Z=f(X,Y) of the three-dimensional spatial coordinate surface obtained in step S200, the actual three-dimensional physical coordinates of the reflection array element can be obtained. .

[0089] Then, based on the actual three-dimensional physical coordinates and the preset three-dimensional coordinates of the base station and 3D spatial predicted coordinates Solve for the spatial optical path difference of beam transmission, and calculate the physical geometric phase deviation of each reflection array element based on the spatial optical path difference.

[0090] Specifically, the following formula is used to calculate the first... Spatial geometric phase deviation of each reflection element relative to the ideal planar state:

[0091]

[0092] ;

[0093] in, The operating wavelength for millimeter waves; The actual three-dimensional physical coordinates of the (m,n)th reflection element; The base station's three-dimensional coordinates; Predict coordinates in three-dimensional space; It is the sum of the spatial distances from the (m,n)th reflection element to the base station and the mobile terminal under the assumption of an ideal two-dimensional plane.

[0094] It should be added that, The calculation method is as follows: Under the assumption of an ideal two-dimensional plane, the flexible intelligent reflective surface does not deform, and all reflective array elements are located on the same reference plane. In this embodiment, the height of the reference plane is taken. Then the first The ideal coordinates of each reflection element are: .at this time:

[0095]

[0096] ;

[0097] By subtracting the sum of spatial distances in the actual curved surface state from the sum of spatial distances in the ideal planar state, the physical geometric phase deviation introduced by the deformation of the flexible intelligent reflective surface and the change in the position of the mobile terminal can be quantified.

[0098] S500: Vector superposition of thermal dielectric phase offset and physical geometric phase deviation to generate total phase distortion matrix.

[0099] In this step, vector superposition refers to multiplying the thermal dielectric phase offset by the complex exponential phase factor corresponding to the physical geometric phase deviation in the complex amplitude domain, which is equivalent to the algebraic sum of the phase angles of each reflection array element. For the th Each reflection element, total phase distortion for:

[0100] ;

[0101] By iterating through all reflection array elements, the total phase distortion of each element is arranged in the original element arrangement order, thus generating the total phase distortion matrix. This comprehensively characterizes the combined phase distortion of the flexible intelligent reflective surface caused by temperature drift, surface deformation, and the movement of the mobile terminal at the current moment.

[0102] S600: Calculate the real-time signal-to-noise ratio (SNR) estimate based on link channel status data.

[0103] The base station-side channel evaluation module receives link channel status data reported by the mobile terminal, extracts channel gain and noise power from it, and calculates the real-time signal-to-noise ratio (SNR) estimate for the current transmission cycle according to the conventional SNR definition. This is a routine process in communication systems and will not be elaborated upon here.

[0104] S700 When the real-time signal-to-noise ratio prediction is less than the preset communication quality threshold, or the maximum offset in the total phase distortion matrix is ​​greater than the preset phase tolerance threshold, the reverse phase compensation matrix is ​​solved based on the total phase distortion matrix and the target focusing phase.

[0105] This step is the core of the control decision-making process. The communication quality threshold is set according to the signal-to-noise ratio threshold required by the minimum modulation and coding scheme of the millimeter-wave communication link; the phase tolerance threshold is set according to the sidelobe suppression requirements of beamforming. When the maximum offset in the total phase distortion matrix exceeds the phase tolerance threshold, phase compensation is triggered even if the current signal-to-noise ratio is not lower than the communication quality threshold to prevent communication quality degradation.

[0106] When the above triggering conditions are met, the control decision module calculates the reverse phase compensation matrix based on the total phase distortion matrix and the target focusing phase. (Target focusing phase) For the ideal alignment state, the first The desired beamforming phase required for each reflector element is calculated based on the base station coordinates, the predicted coordinates of the mobile terminal, and the reflection law under the ideal plane assumption. This is a conventional technique in the field of intelligent reflector beamforming. (Reverse phase compensation matrix) The solution principle is as follows: apply phase compensation equal in magnitude and opposite in direction to each reflection array element, and determine the compensated absolute phase value in conjunction with the target focusing phase, that is:

[0107] ;

[0108] in, For the first The elements of each reflection element in the reverse phase compensation matrix; For the first The target focusing phase of each reflection array element; For the first The total phase distortion of all reflection elements. Arranging the compensation phases of all reflection elements in the element arrangement order yields the reverse phase compensation matrix. In subsequent steps, it is converted into an executable bias voltage control command.

[0109] S800: Based on the reverse phase compensation matrix, look up the preset voltage mapping table, generate the bias voltage control command, and send the bias voltage control command to the control chip of the flexible intelligent reflective surface to drive each reflective array element to complete the phase adjustment.

[0110] This step transforms the abstract phase compensation quantity into a specific hardware control voltage. The key lies in the preset voltage mapping table and the phase-voltage conversion process.

[0111] The result of step S700 Adjust the phase value with respect to the target of this step. For the same physical quantity, the following will be uniformly referred to as express.

[0112] First, calculate the first using the following formula. The target phase value of each reflection element is adjusted. :

[0113] ;

[0114] in, For the ideal alignment state, the first The desired beamforming phase required for each reflection element; For the first Thermal dielectric phase offset of each reflective element; For the first The physical geometric phase deviation of each reflection element; it should be noted that the desired beamforming phase minus the phase shift introduced by temperature, and then minus the phase shift introduced by geometric deformation, yields the original phase value that each element actually needs to be adjusted.

[0115] Adjust the phase value of the target To carry out For periodic phase mapping, obtain the state at... Target phase adjustment within the interval Phase mapping is implemented using modulo operations, that is:

[0116] ;

[0117] If the mapping result is less than zero, then add... To ensure that the target adjustment phase falls within Within the range.

[0118] Next, adjust the phase according to the target. The voltage mapping table matches the corresponding bias voltage values. The voltage mapping table is established offline before system deployment: for each reflector element, multiple different bias voltages are applied sequentially, the equivalent capacitance of the varactor diodes at each voltage is measured, and the corresponding phase response is calculated based on the circuit topology of the reflector element, thus establishing the phase-voltage correspondence of the reflector element. The calibration data of all elements are then summarized to form a complete voltage mapping table. During real-time operation, the drive control module... The corresponding bias voltage value is obtained by looking up the table and encapsulated as a bias voltage control instruction.

[0119] Finally, the bias voltage control command is sent to the control chip of the flexible intelligent reflector via a wired bus. The control chip uses its internal multiplexer to convert the digital command into an analog voltage signal, which is then amplified by the voltage drive amplifier interface and applied to the corresponding varactor diodes. This changes the equivalent capacitance of each reflector element, thereby driving each reflector element to complete phase adjustment and achieve beam refocusing and alignment.

[0120] S900 performs closed-loop fine-tuning. After driving each reflection array element to complete phase adjustment, the system enters the closed-loop verification phase. Updated channel state data for the current transmission cycle after adjustment is acquired, and the signal-to-noise ratio (SNR) improvement is determined based on this data to be greater than a preset gain threshold. The gain threshold is set according to the system's convergence speed requirements and is used to measure the effectiveness of this phase adjustment.

[0121] If the signal-to-noise ratio improvement is greater than the gain threshold, it indicates that the phase adjustment effect meets expectations. The system maintains the current bias voltage control command and waits for the next cycle to re-execute steps S100 to S800.

[0122] If the signal-to-noise ratio improvement is less than or equal to the gain threshold, it indicates a residual deviation between the actual phase response and the calibration model (e.g., caused by factors such as varactor diode aging or sudden changes in ambient temperature). In this case, a local pilot scan procedure is triggered to fine-tune the voltage amplitude in the bias voltage control command. The specific execution method of the local pilot scan procedure is as follows: Centered on the current bias voltage, within a preset local scan range (e.g., ... , (Preset scan half-width) with a fixed step size The bias voltage is changed point by point. At each voltage point, the base station sends a pilot signal. The mobile terminal measures and reports the received signal-to-noise ratio (SNR) at the corresponding voltage point. After traversing all voltage points within the scanning range, the voltage value that maximizes the SNR is selected as the fine-tuned bias voltage. The bias voltage control command is then updated and re-issued for execution. Local pilot scanning is triggered only when the SNR improvement is insufficient. The scanning range is much smaller than the full calibration range, thus not significantly increasing system overhead. At the same time, it can effectively eliminate residual phase errors and ensure the long-term stability of the communication link.

[0123] Reference Figure 2 A smart reflector-assisted millimeter-wave communication link enhancement system is provided to implement the smart reflector-assisted millimeter-wave communication link enhancement method of Example 1. The system includes:

[0124] The data acquisition module is used to acquire strain data reported by the strain sensor array deployed on the back of the flexible smart reflective surface, temperature data reported by the temperature sensor array, and attitude motion data and link channel status data reported by the mobile terminal through the wireless channel.

[0125] The surface reconstruction module is used to generate the three-dimensional spatial coordinate surface equation of the flexible intelligent reflective surface based on strain data and using a preset surface reconstruction model.

[0126] The temperature drift calculation module is used to input temperature data into a preset electromagnetic-temperature mapping relationship and calculate the thermal dielectric phase offset of each reflective element in the flexible intelligent reflective surface.

[0127] The geometric deviation calculation module is used to predict the spatial position coordinates of the mobile terminal based on the attitude motion data, and calculate the physical geometric phase deviation of each reflection array element relative to the base station and the mobile terminal by combining the three-dimensional spatial coordinate surface equation.

[0128] The phase fusion module is used to vector superimpose the thermal dielectric phase offset and the physical geometric phase deviation to generate a total phase distortion matrix.

[0129] The channel evaluation module is used to calculate the real-time signal-to-noise ratio prediction based on link channel status data.

[0130] The control decision module is used to solve the inverse phase compensation matrix based on the total phase distortion matrix and the target focusing phase when the real-time signal-to-noise ratio prediction is less than the preset communication quality threshold, or the maximum offset in the total phase distortion matrix is ​​greater than the preset phase tolerance threshold.

[0131] The drive control module is used to look up a preset voltage mapping table based on the reverse phase compensation matrix, generate a bias voltage control command, and send the bias voltage control command to the control chip of the flexible intelligent reflective surface to drive each reflective array element to complete phase adjustment.

[0132] In this embodiment, the system also includes a flexible printed circuit board (FPC) deployed on the back of the flexible smart reflective surface at the hardware level. The flexible printed circuit board integrates a strain sensor array and a temperature sensor array.

[0133] The strain sensor array includes multiple miniature piezoresistive strain gauges evenly distributed in a grid pattern, used to synchronously acquire the local strain tensor of the flexible substrate under bending stress at multiple points.

[0134] The temperature sensor array includes multiple thermistor sensing units (such as NTC thermistors) attached in multiple regions to sense the real-time operating temperature of each local array element of the flexible reflective surface in sections.

[0135] Furthermore, the control chip includes a multiplex digital-to-analog converter (DAC) and a voltage drive amplification interface that is electrically connected to the varactor diode array of the flexible smart reflector. This interface is used to convert the bias voltage control command into a continuously changing analog voltage applied to the two ends of the corresponding varactor diode. By changing the capacitance of the varactor diode, continuous or high-resolution control of the reflection phase of each reflector element can be achieved.

[0136] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the protection scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for enhancing millimeter-wave communication links assisted by intelligent reflectors, characterized in that, The specific steps include: S100: Acquire strain data reported by the strain sensor array deployed on the back of the flexible smart reflective surface, temperature data reported by the temperature sensor array, and attitude motion data and link channel status data reported by the mobile terminal through the wireless channel. S200. Based on the strain data, generate the three-dimensional spatial coordinate surface equation of the flexible intelligent reflective surface using a preset surface reconstruction model. S300. Input the temperature data into a preset electromagnetic-temperature mapping relationship and calculate the thermal dielectric phase offset of each reflective element in the flexible intelligent reflective surface. S400. Predict the spatial position coordinates of the mobile terminal based on the attitude motion data, and calculate the physical geometric phase deviation of each reflection element relative to the base station and the mobile terminal by combining the three-dimensional spatial coordinate surface equation. S500: Vector superposition of the thermal dielectric phase offset and the physical geometric phase deviation to generate a total phase distortion matrix; S600. Calculate the real-time signal-to-noise ratio prediction based on the link channel status data; S700. When the real-time signal-to-noise ratio estimate is less than a preset communication quality threshold, or the maximum offset in the total phase distortion matrix is ​​greater than a preset phase tolerance threshold, the reverse phase compensation matrix is ​​solved based on the total phase distortion matrix and the target focusing phase. S800: Based on the reverse phase compensation matrix, look up the preset voltage mapping table, generate a bias voltage control command, and send the bias voltage control command to the control chip of the flexible intelligent reflective surface to drive each reflective array element to complete phase adjustment.

2. The method for enhancing millimeter-wave communication links assisted by a smart reflector according to claim 1, characterized in that, The step of generating the three-dimensional spatial coordinate surface equation of the flexible intelligent reflective surface using a preset surface reconstruction model based on the strain data includes: The strain data is analyzed to obtain the strain tensor along the principal axis of the flexible smart reflective surface, and the strain tensor is substituted into the following formula to calculate the normal curvature of the flexible smart reflective surface at each sampling node: ； in, For nodes Normal curvature at that point; and They are nodes The strain tensor values ​​in the X and Y axis directions; The Poisson's ratio of the substrate material of the flexible intelligent reflective surface; The thickness of the substrate structure of the flexible intelligent reflective surface; Based on the normal curvature at each sampling node, a quadratic surface fitting is performed to obtain the equation of the three-dimensional spatial coordinate surface. .

3. The method for enhancing millimeter-wave communication links assisted by a smart reflector according to claim 1, characterized in that, The step of predicting the spatial position coordinates of the mobile terminal based on the attitude motion data, and calculating the physical geometric phase deviation of each reflection element relative to the base station and the mobile terminal by combining the three-dimensional spatial coordinate surface equation, includes: The three-axis acceleration and three-axis angular velocity are extracted from the attitude motion data, and the three-dimensional spatial predicted coordinates of the mobile terminal in the next time slot are predicted using a preset Kalman filter algorithm. Calculate the actual three-dimensional physical coordinates of each reflection element under the equation of the three-dimensional spatial coordinate surface; Based on the actual three-dimensional physical coordinates, the preset three-dimensional coordinates of the base station, and the predicted three-dimensional spatial coordinates, the spatial optical path difference of the beam transmission is solved, and the physical geometric phase deviation corresponding to each reflector element is calculated based on the spatial optical path difference.

4. The method for enhancing millimeter-wave communication links assisted by a smart reflector according to claim 1, characterized in that, The process of solving for the spatial optical path difference of beam transmission and calculating the physical geometric phase deviation corresponding to each reflection element based on the spatial optical path difference includes: The spatial geometric phase deviation of the (m,n)th reflection element relative to the ideal planar state is calculated using the following formula. : ； in, The operating wavelength for millimeter waves; The actual three-dimensional physical coordinates of the (m,n)th reflection element; The three-dimensional coordinates of the base station; Predict coordinates for the three-dimensional space; It is the sum of the spatial distances from the (m,n)th reflection element to the base station and the mobile terminal under the assumption of an ideal two-dimensional plane.

5. The method for enhancing millimeter-wave communication links assisted by a smart reflector according to claim 1, characterized in that, The step of inputting the temperature data into a preset electromagnetic-temperature mapping relationship and calculating the thermal dielectric phase shift of each reflective element in the flexible intelligent reflective surface includes: Extract the real-time temperature value corresponding to each reflective element from the temperature data, substitute the real-time temperature value into the preset dielectric constant temperature drift function, and determine the microstrip line equivalent dielectric constant of each reflective element at the current moment. The change in propagation constant of the microstrip line is calculated based on the equivalent dielectric constant of the microstrip line, and the change in propagation constant is multiplied by the physical length of the microstrip line of the array element to obtain the thermal dielectric phase offset of the corresponding reflective array element.

6. The method for enhancing millimeter-wave communication links assisted by a smart reflector according to claim 1, characterized in that, The step of looking up a preset voltage mapping table based on the reverse phase compensation matrix to generate a bias voltage control command includes: The target adjustment phase value of the (m,n)th reflection element is calculated using the following formula. : ； in, For the ideal alignment state, the first The desired beamforming phase required for each reflection element; For the first The thermal dielectric phase offset of each reflective element; For the first The physical geometric phase deviation of each reflection element; Adjust the phase value of the target To carry out For periodic phase mapping, obtain the state at... Target phase adjustment within the interval ; Adjust the phase according to the target. Match the corresponding bias voltage value in the voltage mapping table and encapsulate it into the bias voltage control instruction.

7. The method for enhancing millimeter-wave communication links assisted by a smart reflector according to claim 1, characterized in that, After the phase adjustment of each reflective array element is completed, the process further includes: Obtain the updated channel status data for the current transmission cycle after adjustment; Based on the updated channel state data, determine whether the signal-to-noise ratio improvement is greater than a preset gain threshold; If the signal-to-noise ratio improvement is less than or equal to the gain threshold, a local pilot scan procedure is triggered to fine-tune the voltage amplitude in the bias voltage control command.

8. A millimeter-wave communication link enhancement system assisted by an intelligent reflector, characterized in that, include: The data acquisition module is used to acquire strain data reported by the strain sensor array deployed on the back of the flexible smart reflective surface, temperature data reported by the temperature sensor array, and attitude motion data and link channel status data reported by the mobile terminal through the wireless channel. The surface reconstruction module is used to generate the three-dimensional spatial coordinate surface equation of the flexible intelligent reflective surface based on the strain data and using a preset surface reconstruction model. The temperature drift calculation module is used to input the temperature data into a preset electromagnetic-temperature mapping relationship and calculate the thermal dielectric phase shift of each reflective element in the flexible intelligent reflective surface. The geometric deviation calculation module is used to predict the spatial position coordinates of the mobile terminal based on the attitude motion data, and calculate the physical geometric phase deviation of each reflection array element relative to the base station and the mobile terminal by combining the three-dimensional spatial coordinate surface equation. The phase fusion module is used to vector-superimpose the thermal dielectric phase offset and the physical geometric phase deviation to generate a total phase distortion matrix. The channel evaluation module is used to calculate the real-time signal-to-noise ratio prediction based on the link channel state data; The control decision module is used to solve the inverse phase compensation matrix based on the total phase distortion matrix and the target focusing phase when the real-time signal-to-noise ratio prediction is less than a preset communication quality threshold, or the maximum offset in the total phase distortion matrix is ​​greater than a preset phase tolerance threshold. The drive control module is used to look up a preset voltage mapping table according to the reverse phase compensation matrix, generate a bias voltage control command, and send the bias voltage control command to the control chip of the flexible intelligent reflective surface to drive each reflective array element to complete phase adjustment.

9. The intelligent reflector-assisted millimeter-wave communication link enhancement system according to claim 8, characterized in that, The system also includes a flexible printed circuit board deployed on the back of the flexible smart reflective surface, on which the strain sensor array and the temperature sensor array are integrated; The strain sensor array includes multiple miniature piezoresistive strain gauges uniformly distributed in a grid pattern; The temperature sensor array includes multiple thermistor sensing units attached in multiple regions.

10. The intelligent reflector-assisted millimeter-wave communication link enhancement system according to claim 8, characterized in that, The control chip includes a multi-channel digital-to-analog converter and a voltage drive amplification interface that is electrically connected to the varactor diode array of the flexible smart reflective surface in a one-to-one correspondence. It is used to convert the bias voltage control command into a continuously changing analog voltage and apply it to the two ends of the corresponding varactor diode.

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