Research On Wireless Communication Transmission Technology Based On Intelligent Reflecting Surface

The uncontrollability of environmental factors in wireless communication is the key to hindering the further development of mobile communication.Due to the characteristics of linear propagation of electromagnetic waves,the line-of-sight path is easily obstructed by obstacles such as buildings and trees during signal transmission,resulting in incomplete signal coverage and a decrease in service quality.In addition,the energy loss caused by environmental interference and multipath effects would reduce the transmission performance of communication systems.In response to the above issues,this article conducts research on wireless communication transmission technology based on Intelligent Reflecting Surface(IRS),and analyzes the performance of IRS assisted wireless communication systems in Rayleigh and Nakagami-m fading channels.The main research contents of this paper are determined to include:(1)Given the lack of existing research on the performance analysis of multiple cascade IRS-assisted links,this study investigates the performance analysis of multi-IRS-assisted communication systems in Rayleigh fading channels.Besides,a multi-IRS assisted single input single output(SISO)downlink is designed and a general channel model of multi-IRS cascade communication is established.Besides,a block optimization scheme was proposed for the phase shift design of multiple cascaded IRSs while maximizing the end-to-end signalto-noise ratio of the link.In addition,the mathematical expressions of the probability density function and cumulative distribution function of the signal-to-noise ratio are derived,and the outage probability and bit error rate performance of the system are analyzed.Finally,the influence of some key parameters in the link on system performance is discussed.The simulation results show that increasing the number of reflection units on the RIS and increasing the transmit power can improve the system performance,and the deployment position of the IRS in the link should be close to the base station or user side.(2)In the link with semi-passive IRS-assisted communication,the components of the active elements will generate additive noise interference during the process of reflecting the signal.When this part of the noise cannot be ignored,it is necessary to consider the impact of the noise generated by the active components on the impact on system performance.The paper designs a semi-passive IRS-assisted communication link and considers the additive noise generated by the active elements in the process of reflecting the signal.Based on this,the channel model under the Nakagami-m fading channel is established and the end-to-end signal-to-noise ratio expression is deduced,and the outage probability model of the system is obtained.Finally,numerical simulations are carried out using Monte Carlo simulation and the influence of system-related parameters on system outage performance is discussed.