Based On SWIPT Two-way Transmission Relay System Strategy Optimization Research

With the expansion of the wireless network system scale and the arrival of 5G era,the number of network nodes increases greatly,the emergence and development of Simultaneous Wireless Information and Power Transfer(SWIPT)technology has provided new ideas for the power supply of energy-constrained nodes.The SWIPT technology combined with the relay technology can further improve the performance of the communication system.This paper mainly studies the SWIPT two-way transmission relay system,in which two source nodes have fixed energy supply,and the relay needs to harvest RF signals to obtain energy and transmit information using Amplify Forward(AF)transmission protocol.This paper proposes two relay transmission strategies.The paper also discusses the Actual Maximum Throughput(AMT)and communication performance of the two strategies under Time Switching(TS)structure relay and Power Splitting(PS)structure relay.The limited delay relay(LDR)strategy means that there must be strict time synchronization between the receiving node and the sending node,that is,the sending rate equals the receiving rate.If one channel does not meet the communication conditions,then the whole communication system will be completely interrupted.The simulation diagram of LDR strategy is compared with the simulation diagram of one-way transmission relay strategy.The TS-LDR strategy increased throughput by 64% over the one-way transport strategy.The throughput of the PS-LDR strategy increased by 72% over the one-way transport strategy.Next,the effect of transmission rate threshold on the AMT was investigated.The performance of TS-LDR strategy is better when the rate threshold is larger.And PS-LDR strategy is better when the threshold is smaller.The tolerated delay relay(TDR)strategy only needs to consider its own channel conditions,and the maximum information rate transmission is carried out according to its own channel gain,so there will be no interruption due to synchronization.By deducing the ergodic capacity expressions,the AMT expressions of relay receivers with different structure relays are obtained.Furthermore,the expression is optimized to obtain the AMT of the two structure relays and the simulation diagram.Finally,the two strategies proposed in this paper are compared.The effects of uplink noise and energy conversion efficiency on the actual maximum throughput of the two strategies at different relays are discussed.When uplink noise is large,the relay with TS structure has strong capability of noise immunity.When uplink noise is small,the communication efficiency of the relay with PS structure should be better.The communication efficiency of the TDR strategy is much higher than that of the LDR strategy when the information is not fully synchronized,but the LDR strategy must be used to complete the communication when the real-time communication needs to be maintained.If complete synchronization of information is not required,the communication efficiency of the TDR strategy is much higher than that of the LDR strategy.However,when real-time communication is required,the LDR strategy must be used to communicate.