X-Duplex And IRS-Assisted Relay Network With Wireless Power Transfer

With the rapid development of wireless communication technology,the rapid growth of communication data,the massive emergence of wireless connections and the large-scale construction of network infrastructure,the problems of energy shortage and lack of spectrum resources have become increasingly prominent.In order to improve energy efficiency and spectrum efficiency,and to solve the problem of self-interference in the full duplex mode in the traditional relay model,this paper studies the adaptive transmission scheme of relay network assisted by X-Duplex and intelligent reflecting surface.The main work and innovation of this paper are as follows:1.Aiming at the problem of energy supply and spectrum utilization caused by idle spectrum detection in cognitive radio network,this paper proposes a two-way amplify-and-forward relay scheme based on radio frequency energy harvesting and X-Duplex with the goal of maximizing the system sum rate.Different from the communication mode of half duplex used in traditional two-way relay,the X-Duplex relay model proposed in this paper can dynamically switch to full duplex mode without disturbing the primary users.This scheme can obtain energy from the radio frequency signal.For the self-interference signal generated in full duplex mode,this paper converts the interference signal into energy and collects it to provide energy for the node equipment with limited energy,and realizes the simultaneously wireless information and power transfer.Further,using the power splitting protocol,the X-Duplex relay divides the received radio frequency signal into two parts according to a power split ratio,one part is used for energy harvesting,and the other part is used for information processing,and an optimal power allocation algorithm is proposed to maximize the system sum rate.Finally,through the comparative analysis of simulation,it is verified that the algorithm designed in this paper has advantages in improving the sum rate and energy efficiency performance of the system.2.Intelligent reflecting surface is considered as a new wireless enabling technologies in 6G mobile communications because it can intelligently control the radio transmission environment.This paper considers intelligent reflecting surface-assisted relay simultaneously wireless information and power transfer.Different from the existing work,which compares the intelligent reflecting surface with the simple amplify-and-forward/decode-and-forward relay in half duplex mode,this paper combines it with the X-Duplex relay,and proposes an intelligent reflecting surface transmission scheme based on X-Duplex.When the radio frequency signal transmitted by the wireless access point has an obstacle of non-line of sight transmission,the wireless information and energy can be simultaneously transmitted through the X-Dduplex and intelligent reflecting surface-assisted relay network.For the transmission of three different paths,this paper establishes a transmission power consumption model based on real scenarios,and correspondingly designs three energy efficiency maximization algorithms to optimize the energy efficiency performance of different paths,and explores the energy efficiency and weighted sum rate performance of the three paths.The simulation results show that although intelligent reflecting surface has more advantages in energy efficiency when the transmission power is sufficient,it cannot completely replace the traditional relay technology.The joint deployment of X-Duplex relay and IRS can meet different transmission requirements.Therefore,choosing the best transmission mode can finally make the network have better performance such as more reliability,large capacity,greater fraction of coverage and low energy consumption.