CN-116488692-B - Sub-6 wireless network communication enhancement method based on double-frequency programmable super surface

CN116488692BCN 116488692 BCN116488692 BCN 116488692BCN-116488692-B

Abstract

The application relates to a Sub-6 wireless network communication enhancement method based on a double-frequency programmable super-surface, which has the advantages of compact area, low cost and simple structure based on the double-frequency programmable super-surface structure, supports the simultaneous realization of beam forming on two Sub-6ISM wave bands, ensures that the Internet of things equipment with different frequencies and different protocols can have the beam forming capability, and can realize the beam forming on the two Sub-6ISM frequency bands simultaneously so as to improve the wireless communication performance of commercial Internet of things equipment.

Inventors

CHEN XIAOJIANG
WANG XIAOJING
ZHANG YANGFAN
FENG CHAO
LI XINYI
FANG DINGYI

Assignees

西北大学

Dates

Publication Date: 20260505
Application Date: 20230407

Claims (3)

1. A Sub-6 wireless network communication enhancement method based on a dual-frequency programmable subsurface, comprising: constructing a double-frequency programmable subsurface structure, wherein the double-frequency programmable subsurface structure comprises a plurality of subsurface units, each subsurface unit can generate resonance frequencies of two frequency bands, and each subsurface unit can generate four phase values; determining the optimal coding mode of the dual-frequency programmable super-surface structure for realizing dual-frequency band beam forming under different incidence angles and different emergence angles; determining at least one super-surface unit in the optimal coding mode that has little or no negative impact on the main lobe; Determining a coding mode capable of providing an optimal communication signal quality as a final coding mode at different angles of incidence and emergence from said optimal coding mode and said at least one super-surface unit having little or no negative impact on the main lobe; Detecting the relative direction of a target, wherein the relative direction is an incident angle of an uplink or an emergent angle of a downlink, and selecting the final coding mode corresponding to the relative direction of the target as a coding mode adopted by communication; the super surface unit comprises a metal square patch at the top, a dielectric cube in the middle and a metal layer at the bottom, wherein the width of the metal square patch Is that Length of the metal square patch Is that Height of the dielectric cube Is that ; The upper left, lower left, upper right and lower right edges of the metal square patch are etched with a groove, and the width of each groove Is that Groove length Is that ; A rectangular groove is etched between two grooves in the same column along the column direction, and a PIN diode is embedded in each rectangular groove; the two PIN diodes are respectively in an 'on' state or an 'off' state under different direct-current voltage levels, and four states of the super-surface unit are obtained through combination so as to generate four corresponding phase values; The method for determining the optimal coding mode for realizing the dual-band beam forming by the dual-frequency programmable super-surface structure under different incident angles and exit angles comprises the following steps: Constructing an objective function: Wherein, the In order to achieve the best mode of encoding, For a theoretical maximum signal strength achieved at the 2.4GHz band using the best phase offset, Theoretical maximum signal strength achieved on the 5GHz band for best phase offset; The intensity of the 2.4GHz signal reflected for the dual-frequency programmable subsurface structure, Intensity of 5GHz signal reflected for the dual-frequency programmable subsurface structure; Intensity of 2.4 GHz signal reflected by the dual-frequency programmable subsurface structure: Wherein, the To generate an incident angle of the 2.4GHz signal, The exit angle of the 2.4GHz signal reflected for the subsurface unit, Along the emergence angle for a super-surface unit The amplitude of the reflected 2.4GHz signal, M being the number of rows of the subsurface units in the dual-frequency programmable subsurface structure, N being the number of columns of the subsurface units in the dual-frequency programmable subsurface structure, For the coding mode of the double-frequency programmable super-surface structure corresponding to the theoretical maximum signal intensity realized on the 2.4GHz frequency band, For coding mode Middle (f) The phase states of the individual subsurface units; representing the phase; intensity of the 5GHz signal reflected by the dual-frequency programmable subsurface structure: Wherein, the To generate an incident angle of the 5GHz signal, The exit angle of the 5GHz signal reflected for the subsurface unit, Along the emergence angle for a super-surface unit The amplitude of the reflected 5GHz signal, For the coding mode of the double-frequency programmable super-surface structure corresponding to the theoretical maximum signal intensity realized on the 5GHz frequency band, For coding mode Middle (f) The phase states of the individual subsurface units; representing the phase; Solving the objective function to obtain an optimal coding mode of the dual-frequency programmable super-surface structure for realizing dual-band beam forming; Wherein determining at least one super-surface unit in the optimal coding mode that has little or no negative impact on the main lobe comprises: Determining a set of super surface units with little or no negative impact on the main lobe in the 2.4GHz band : Wherein, the Is the phase of the main lobe of the 2.4GHz frequency band, The phase is represented by the phase-finding, To generate an incident angle of the 2.4GHz signal, The exit angle of the 2.4 GHz signal for the subsurface unit reflection, The frequency is shown to be 2.4GHz, Is the best coding mode The phase states of the individual subsurface units; 2.4GHz frequency band main lobe phase : Wherein, the For phase, M is the number of rows of the super-surface units in the dual-frequency programmable super-surface structure, and N is the number of columns of the super-surface units in the dual-frequency programmable super-surface structure; Determining a set of super surface units that have little or no negative impact on the main lobe in the 5GHz band : Wherein, the Is the phase of the main lobe of the 5GHz frequency band, To generate an incident angle of the 5GHz signal, The exit angle of the 5GHz signal reflected for the subsurface unit, The frequency is indicated as 5GHz, Is the best coding mode The phase states of the individual subsurface units; Phase of main lobe of 5GHz frequency band : Solving the set of the super-surface units in the frequency band of 2.4GHz And the set of subsurface units in the 5GHz band Is the intersection of (1) As at least one supersurface element in the dual-frequency programmable supersurface structure that has little or no negative effect on the main lobe; Wherein determining a coding mode capable of providing an optimal communication signal quality as a final coding mode at different angles of incidence and exit, based on said optimal coding mode and said at least one super surface unit having little or no negative effect on the main lobe, comprises: for the optimal coding mode corresponding to each group of incidence angle and emergence angle, changing the phase state of at least one super-surface unit with little or even negative influence on the main lobe in the optimal coding mode to obtain a plurality of updated coding modes; And determining a coding mode capable of providing the best communication signal quality among the plurality of updated coding modes as a final coding mode.
2. The method of claim 1, wherein said solving said objective function comprises: Adopting a genetic algorithm to solve the objective function, and in the solving process, using a coding mode of a double-frequency programmable super-surface structure corresponding to the theoretical maximum signal intensity realized on the 2.4GHz frequency band Coding mode of double-frequency programmable super-surface structure corresponding to theoretical maximum signal intensity realized on 5GHz frequency band As an initial chromosome in the initial population of the genetic algorithm.
3. A Sub-6 wireless network communication enhancement device based on a dual-frequency programmable subsurface, comprising: the double-frequency programmable super-surface structure comprises a plurality of super-surface units, wherein each super-surface unit can generate resonance frequencies of two frequency bands, and each super-surface unit can generate four phase values; The optimal coding mode determining module is used for determining an optimal coding mode for realizing dual-band beam forming by the dual-frequency programmable super-surface structure under different incidence angles and different emergence angles; A negative influence super-surface unit determining module for determining at least one super-surface unit having little or no negative influence on the main lobe in the optimal coding mode; A final coding mode determining module, configured to determine, according to the optimal coding mode and the at least one super-surface unit that has little or no negative effect on the main lobe, a coding mode that can provide optimal communication signal quality as a final coding mode at different incident angles and exit angles; the communication coding mode determining module is used for detecting an incidence angle or an emergence angle corresponding to a target, and selecting the final coding mode corresponding to the incidence angle or the emergence angle corresponding to the target as a coding mode adopted by communication; the best coding mode determining module is further configured to: Constructing an objective function: Wherein, the In order to achieve the best mode of encoding, For a theoretical maximum signal strength achieved at the 2.4GHz band using the best phase offset, Theoretical maximum signal strength achieved on the 5GHz band for best phase offset; The intensity of the 2.4GHz signal reflected for the dual-frequency programmable subsurface structure, Intensity of 5GHz signal reflected for the dual-frequency programmable subsurface structure; Intensity of 2.4GHz signal reflected by the dual-frequency programmable subsurface structure: Wherein, the To generate an incident angle of the 2.4GHz signal, The exit angle of the 2.4GHz signal reflected for the subsurface unit, Along the emergence angle for a super-surface unit The amplitude of the reflected 2.4GHz signal, M being the number of rows of the subsurface units in the dual-frequency programmable subsurface structure, N being the number of columns of the subsurface units in the dual-frequency programmable subsurface structure, For the coding mode of the double-frequency programmable super-surface structure corresponding to the theoretical maximum signal intensity realized on the 2.4GHz frequency band, For coding mode Middle (f) The phase states of the individual subsurface units; representing the phase; Calculating the intensity of the 5GHz signal reflected by the double-frequency programmable super-surface structure: Wherein, the To generate an incident angle of the 5GHz signal, The exit angle of the 5GHz signal reflected for the subsurface unit, Along the emergence angle for a super-surface unit The amplitude of the reflected 5GHz signal, For the coding mode of the double-frequency programmable super-surface structure corresponding to the theoretical maximum signal intensity realized on the 5GHz frequency band, For coding mode Middle (f) The phase states of the individual subsurface units; representing the phase; Solving the objective function to obtain an optimal coding mode of the dual-frequency programmable super-surface structure for realizing dual-band beam forming; The negative impact super surface unit determination module is further configured to: Determining a set of super surface units with little or no negative impact on the main lobe in the 2.4GHz band : Wherein, the Is the phase of the main lobe of the 2.4GHz frequency band, The phase is represented by the phase-finding, To generate an incident angle of the 2.4GHz signal, The exit angle of the 2.4GHz signal reflected for the subsurface unit, The frequency is shown to be 2.4GHz, Is the best coding mode The phase states of the individual subsurface units; 2.4GHz frequency band main lobe phase : Wherein, the For phase, M is the number of rows of the super-surface units in the dual-frequency programmable super-surface structure, and N is the number of columns of the super-surface units in the dual-frequency programmable super-surface structure; Determining a set of super surface units that have little or no negative impact on the main lobe in the 5GHz band : Wherein, the Is the phase of the main lobe of the 5GHz frequency band, To generate an incident angle of the 5GHz signal, The exit angle of the 5GHz signal reflected for the subsurface unit, The frequency is indicated as 5GHz, Is the best coding mode The phase states of the individual subsurface units; Phase of main lobe of 5GHz frequency band : Solving the set of the super-surface units in the frequency band of 2.4GHz And the set of subsurface units in the 5GHz band Is the intersection of (1) As at least one super-surface unit that has little or no negative effect on the main lobe in the optimal coding mode; the super surface unit comprises a metal square patch at the top, a dielectric cube in the middle and a metal layer at the bottom, wherein the width of the metal square patch Is that Length of the metal square patch Is that Height of the dielectric cube Is that ; The upper left, lower left, upper right and lower right edges of the metal square patch are etched with a groove, and the width of each groove Is that Groove length Is that ; A rectangular groove is etched between two grooves in the same column along the column direction, and a PIN diode is embedded in each rectangular groove; the two PIN diodes are respectively in an 'on' state or an 'off' state under different direct-current voltage levels, and four states of the super-surface unit are obtained through combination so as to generate four corresponding phase values; The final coding mode determining module is further configured to: for the optimal coding mode corresponding to each group of incidence angle and emergence angle, changing the phase state of at least one super-surface unit with little or even negative influence on the main lobe in the optimal coding mode to obtain a plurality of updated coding modes; And determining a coding mode capable of providing the best communication signal quality among the plurality of updated coding modes as a final coding mode.

Description

Sub-6 wireless network communication enhancement method based on double-frequency programmable super surface Technical Field The application relates to the field of communication of the Internet of things, in particular to a Sub-6 wireless network communication enhancement method based on a double-frequency programmable super surface. Background Most of the internet of things equipment is limited by factors such as size, power consumption and price, and usually only fewer than three antennas are provided. Due to the influence of environmental multipath and other factors, the beam patterns of the cheap few antennas cannot ensure uniform and stable signal propagation in a complex indoor environment, so that the communication efficiency is low. Thus, beamforming techniques are often utilized in wireless communication systems to increase link throughput and extend communication range. Much research is devoted to using antenna arrays at radio frequency terminals to achieve high beamforming gains. In practical applications, however, the real deployment of radio systems with large antenna arrays faces two significant challenges, firstly, due to cost and form factor limitations, most of today's internet of things devices must be small in size, not have enough space to accommodate the bulky antenna arrays, and secondly, these systems require tightly integrated antennas, radio frequency front ends and baseband hardware, resulting in increased power consumption and high hardware costs. Recently, the transfer of beamforming functionality from the communication end to intelligent surfaces deployed in a propagation environment has attracted attention from many researchers, such as LAIA, RFocus, RFlens, and the like. While these smart surfaces may implement beamforming, they are also limited in practice. First, the area is large. For example, RFocus uses 3200 antenna elements, a total of 6 square meters of area achieves a median gain of 9dB for the wireless link, such a large super surface is difficult to flexibly deploy in complex environments. And RFocus only a portion of the cells are utilized at a time, redirecting only a small portion of the signal energy, the area utilization efficiency is high. Secondly, the working frequency band is limited. It is observed that current super-surface based beamforming solutions focus on optimizing communication performance on a single frequency band, e.g., RFocus for frequencies below 3GHz and RFlens for the 5GHz band. But internet of things equipment (cameras, intelligent bulbs and the like) often work in different frequency bands (2.4 GHz and 5 GHz), different protocols (such as Wi-Fi, bluetooth and ZigBee), deployment of intensive internet of things equipment is very common in concurrent wireless transmission through two Sub-6 ISM frequency bands (2.4 GHz and 5 GHz), and therefore single-frequency super-surface cannot meet practical application. In order to support the operation of the internet of things equipment in dual frequency bands, one straightforward solution is to deploy two single frequency super surfaces operating in different frequency bands. However, this not only requires more deployment space to accommodate the additional super surface, but also results in higher costs. Another solution is to stack one subsurface above the other, but such approaches result in a complex control circuit design. Recently, work has been done to use varactors to adjust the phase to achieve dual frequency operation, which introduces high insertion loss and requires accurate and complex dc voltage control back-end. In summary, the existing beamforming technology has shortcomings in efficiency, universality and the like. There is therefore a need for beamforming techniques with higher feasibility. Disclosure of Invention In order to overcome at least one defect in the prior art, the application provides a Sub-6 wireless network communication enhancement method based on a double-frequency programmable super-surface. In a first aspect, a Sub-6 wireless network communication enhancement method based on a dual-frequency programmable subsurface is provided, including: constructing a double-frequency programmable subsurface structure, wherein the double-frequency programmable subsurface structure comprises a plurality of subsurface units, each subsurface unit can generate resonance frequencies of two frequency bands, and each subsurface unit can generate four phase values; determining the optimal coding mode for realizing dual-band beam forming by the dual-frequency programmable super-surface structure under different incidence angles and different emergence angles; Determining at least one super-surface unit that has little or no negative impact on the main lobe in the optimal coding mode; Determining a coding mode capable of providing an optimal communication signal quality as a final coding mode at different angles of incidence and emergence, based on the optimal coding mode and at least one