Transmission Performance Analysis Of Internet Of Things With Nonlinear Wireless Energy Harvesting Model

With the large-scale deployment of sensors,the energy supply of network nodes has become a bottleneck in the development of the Internet of Things(IoT).Frequent replacement of batteries in special scenarios is difficult.In order to solve the above problem,the academia has proposed wireless radio frequency(RF)energy harvesting(EH)technology.At present,many basic issues need to be studied urgently as the technology is relatively new.Most of the previous works about wireless EH network have assumed an ideal linear EH model.But many important conclusions obtained by previous work have deviation from the actual system because they all ignore the nonlinear characteristics of diodes and other components.At the same time,the randomness of the wireless link leads to great uncertainties in both energy harvesting and rate of decoding information which causes the outage of information transmission at end-to-end.The outage performance analysis of the information transmission is an important indicator in a random fading link.Therefore,this paper studies the transmission outage performance of two representative network model based on the nonlinear energy harvesting model.The specific work content and innovations are as follows:(1)For single-user two-hop multi-relay simultaneous wireless information and power transfer(SWIPT)network,the information outage performance of end-to-end is analyzed based on the nonlinear EH model.The relays adopt decode-and-forward scheme and time splitting(TS)receiver structure.Based on the Kth best relay selection criterion,the closed-form expression for outage probability is given under Rayleigh fading model and the average throughput expression is further obtained.We verify the accuracy of the derived analytical expression using the Mont Carlo simulation.Then the closed-form expression is used to simulate the influence of different system parameters,and simulation shows that increasing the number of relays properly can reduce the outage probability effectively.At the same time,the smaller the selected number of relays,the smaller the system outage probability is.It is worth mentioning that all the conclusions of this work are obtained under the imperfect link state information which leads to a more difficult solution and the conclusions obtained are more general and closer to the actual situation.(2)For multi-user single-hop wireless powered communication network-SWIPT(WPCN-SWIPT),the information outage performance of end-to-end is analyzed based on the nonlinear EH model.The information source node first harvests energy from RF signals and then transmits information and energy to multiple sensor nodes using the harvested energy.The sensor nodes adopt power splitting(PS)receiver structure.The closed-form expression of outage probability is given under the Nakagami-m fading model and the average throughput expression is further obtained.In order to further finding the law of the system,the asymptotic outage probability and the asymptotic average throughput are given under high transmit power.Mont Carlo simulation results are presented to verify the accuracy of the derived closed-form expression.We can see that the larger the link fading factor m,the smaller the system outage probability is.We can also see that the average throughput of the system increases first and then decreases with the increase of charging time under the given transmission time.