Research On Anti-Interference Strategy Of WiFi In WLAN

With the rapid development of WLAN(Wireless Local Area Network)technology,WLAN has gradually assumed an important communication role in people's work,office,and daily life.The most widely used WLAN network is the WiFi(Wireless Fidelity)technology,which uses the 802.11 protocol standard.Most wireless manufacturers adopt this standard and use WiFi to deploy wireless networks.But with the gradual increase in the number of wireless networks and wireless devices,the problems that follow have gradually emerged.WiFi uses an unlicensed frequency band.There are many various wireless devices and communication systems in this frequency band.They will compete with WiFi for the resources of this frequency band,which will seriously degrade the performance of the WiFi network.In addition,different WiFi networks They will also interfere with each other due to different standards.And with the rapid development of IOT(IOT: Internet of Things)technology,in the future,almost all electronic devices will use wireless transmission technology,many of which will work in the WiFi working frequency band,which will affect future WiFi networks.Come a more severe test.Therefore,how to make WiFi networks work better under the influence of various interferences is a very important research topic.Aiming at this problem,this paper discusses and researches it in combination with theory and experimental simulation.Starting from the composition of the WiFi network,this article first briefly describes the different network types and analyzes their respective working scenarios;then introduces the different interferences that exist in the WiFi network,and introduces their respective characteristics and characteristics.The way it affects the network is analyzed.Then,before modeling,the key technologies in the MAC layer are introduced in detail,then the existing Markov chain model is discussed,and the improved unsaturated model is simulated and analyzed.In this paper,different types of interference sources are divided into three categories based on their characteristics: continuous interference,non-continuous interference,and non-local WiFi site interference.The original unsaturated model did not consider the interference problem.This article has improved and perfected it,introduced these three types of interference into the model,and obtained the state transition equations of the station under different interference models,and the difference between the stations The data transmission probability,collision probability,and throughput performance under interference are deduced,and then the interference network performance under the basic access mechanism and RTS/CTS access mechanism is simulated,and the network performance under different interference is analyzed.The following interference The study of avoidance strategies provides a suitable network model.Finally,based on the interference model proposed in this paper,the throughput performance of the network with different transmission rates under different interference intensities is simulated and analyzed;according to the analysis results,a variable rate-based interference avoidance strategy is proposed.In this strategy,the network selects its transmission rate based on the interference intensity in the channel,so that the network always maintains the best transmission rate under different interference intensities,so that the network can always be in the best working state.And compared it with the traditional rate adjustment algorithm.The simulation results show that this strategy can significantly improve the performance of the network compared with other algorithms.