Research On Sensing Performance Optimization In Wireless System Based On Wireless Radio Frequency Signal

Radio frequency signals are widely used in wireless systems to promote the deployment of wireless systems in every corner of life,such as Wi Fi systems,Zigbee systems,BLE systems,and wireless charging systems.The perception of wireless devices in these wireless systems is an important link connecting the physical world and the information world,and has attracted extensive attention from academia and industry.The radio frequency signal of the wireless system can both spread data information and carry energy.The perceived performance of a wireless system is affected by the stability of the signals in the transceiver link,the connectivity of multiple transmitter,and the fault tolerance of complex tasks.Specifically,firstly,the receiving device of the wireless system can calculate the channel state information(Channel State Information,CSI)of the wireless channel through the data information transmitted by the radio frequency signal.The channel state information reflects the change of the environment,that is,the CSI measurement has a certain relationship with the movement of the target object in the environment.So the stability of obtained the CSI measurement is directly related to the change range of the target object's motion in the sensing environment,the target's surface area,and the maximum coverage of the sensing object.Secondly,the relationship between the position and orientation of deployment among multiple transmitters,as well as the coordinated scheduling and clock synchronization among multiple transmitters will affect the performance of the receivers in sensing energy changes.Finally,when the device nodes of the wireless system perform complex tasks,such as monitoring of fires,monitoring of enemy incursions on the battlefield,etc.,some device nodes may not work properly due to the harsh environment,and these that cannot work properly may cause important perception tasks to fail.This article aims to break the bottleneck of the wireless system's perceived performance,so that the wireless system can continue to run steadily for a long time.Based on this research goal,this paper aims at the main problems of wireless system in perception performance optimization.From the stability,connectivity,and fault tolerance of wireless system's perception performance,the research point is to obtain stable channel state information for the physical layer to measure gesture movement distance and direction,the deployment of multiple connected energy transmitters at the network layer to maximize the sensing power performance of the receivers,and the deployment of fault-tolerant energy transmitters at the task layer to maximize the perception.After in-depth research,the following research conclusions were obtained:(1)We study the optimization of the perception performance of the physical layer stability of wireless systems,that is,to obtain stable physical layer signals under simple commercial equipment deployment conditions,thereby achieving fine-grained perception of gesture movement distance and direction.Specifically,we study the sources of unstable channel state information related to the physical layer extracted from commercial Wi Fi network cards.These sources mainly include the carrier frequency offset of the transmitter and receiver,the sampling frequency offset,the packet detection delay when the receiving end device detects the packet,the interference from other devices,and the noise in the environment.We have carefully analyzed the characteristics of each source of instability and designed algorithms such as phase correction algorithm and local extremum detection to correct the unstable signal obtained.The corresponding mathematical perception model of corrected stable signal and the gesture movement is established,the experiment proves that the algorithm we proposed can indeed perceive the distance and direction of gesture movement in real-time and fine-grained.The stability of the physical layer perception performance can provide a guarantee for the smooth operation of the upper layer perception(2)We study the problem of optimizing the perceptual performance under connectivity constraints of the network layer of wireless systems,that is,how to deploy the position of the energy transmitter in the wireless system and select the orientation angle of the directional antenna of the energy transmitter to ensure that the deployedenergy transmitters can communicate with each other,and maximize the perceived performance of the network layer of wireless systems.Specifically,we first propose an algorithm for extracting candidate direction angles,which converts an infinite number of candidate solution spaces of the orientation angle of the energy transmitter into a limited candidate solution space,and constructs a candidate strategy for the candidate position of the energy transmitter and the candidate orientation angle set,at this time,our optimization problem becomes a submodule optimization problem under the condition of connected constraints.Through the proposed dense region partitioning technology,we improve the performance of the best existing algorithm for solving connected submodule maximization.Experimenting with our algorithm further verifies that the proposed algorithm can indeed improve the perception performance under connectivity constraints of network layer.The improvement of the perception performance under connectivity constraints of the network layer can provide a long-term energy guarantee for the stability of the perception performance of the physical layer.(3)We study the problem of perceptual performance optimization of the fault tolerance of the wireless system,that is,tolerate the case where some device nodes with a high correlation of perception in the wireless system do not work,and systems can still achieve wireless by selecting the deployment location of other energy transmitters.The perceptual performance of the system task layer is maximized.Specifically,we use the regional discretization technique to convert multiple wireless candidate locations where the energy transmitter is deployed into a limited number of candidate locations.At this time,our optimization problem becomes a two-layer tightly coupled optimization problem that needs to meet the fault tolerance constraints.Therefore,we propose an algorithm framework for solving convex optimization based on the robust submodule greedy algorithm,and prove in theory of the proposed algorithm is guaranteed with a constant approximate ratio.Through simulation experiments and actual experiments to implement the algorithm we proposed,it was verified that the algorithm we proposed can improve the perception performance of task layer of wireless system.The improvement of the fault-tolerant perception performance of the task layer can provide a robust guarantee for the physical layer and the network layer to complete the perception task.