Research On Power Splitting And Relay Selection In Energy Harvesting Relay Networks

With the rapid development of wireless communication,the energy supply of mobile devices has become particularly prominent.How to continuously provide energy for equipment has become one of the hotspots of research.The emergence of Simultaneous Wireless Information and Power Transfer(SWIPT)based on cooperative transmission of wireless information and energy provides a new way to solve the problem of energy supply,and has attracted extensive attention of researchers.This paper combines SWIPT technology with cooperative communication to study power splitting and relay selection in SWIPT network.The main research work and innovation are as follows:Firstly,we study the power splitting of SWIPT single relay network.We propose an optimal power splitting(OPS)scheme and obtain the optimal power splitting ratio.The relational expression between the outage probability of the OPS scheme and the energy conversion efficiency of the relay is deduced.And the outage probability expression of OPS scheme is simulated.The simulation results show that with the improvement of energy conversion efficiency,the outage performance of the OPS scheme is better.Secondly,we study the relay selection of SWIPT multi-relay network.We split the power,and get the optimal power splitting ratio.We analyze the relay selection and propose the optimal power splitting and relay selection(OPS-RS)scheme.The relational expression between the outage probability of the OPS-RS scheme and the number of relays and the energy conversion efficiency is deduced.And we simulate the outage probability expression of OPS-RS scheme.The simulation results show that with the increase of the number of relays,the outage performance of the OPS-RS scheme becomes better and better.At the same time,with the improvement of energy conversion efficiency,the outage performance of OPS-RS scheme is obviously improved.Finally,the precoding of SWIPT multi-antenna relay network is studied.According to the criterion of maximizing the signal-to-noise ratio(SNR)of the receiver,the optimal precoding matrix is deduced.On this basis,we jointly study the power splitting and relay selection of the network,analyze the OPS-RS scheme in this network,and derive the relational expression between the outage probability of OPS-RS scheme and the number of antennas and relays.And we simulate the outage probability expression of OPS-RS scheme.The simulation results show that the outage probability of the OPS-RS scheme is positively correlated with the number of antennas and relays.That is to say,with the increase of the number of antennas or relays,the outage performance of OPS-RS scheme becomes better and better.