Research On Energy Consumption Of Source In SWIPT Networks With Non-linear Energy Conversion Efficiency

With the advent of the 5G era,the Internet of everything is no longer an untouchable scenario.The rising massive terminal equipment consumes a large amount of energy and spectrum resources.Scholars all over the world are concerned about energy conservation and green communication.In addition,some new network models,such as wireless sensor network,mobile communication network,wireless human local area network and Internet of things,have emerged.The energy source of equipments is one of the bottlenecks in the application and development of energy-limited networksThe simultaneous wireless information and power transfer technology(SWIPT)take the electromagnetic wave as the carrier.It actively collects radio frequency energy stored in the natural environment.SWIPT realizes energy and information transmission between transceiver devices.It addresses the limitations of traditional power supply.SWIPT provides a new opportunity for the future development of green communications.Reducing channel fading and multipath interference and improving spectral efficiency are the advantages of orthogonal frequency division multiplexing(OFDM)and multiantenna technology.SWIPT combined with these technologies,which not only takes their advantages,but also improves the system performance by mining the spatial dimension.Reducing energy consumption while ensuring communication quality is one of the research objectives.But,most of the existing researches on the resource allocation use linear energy harvesting(EH)models.The linear EH model ignores the saturation characteristics of the circuit.Therefore,the effect of these resource allocation algorithms can not achieve the essence of the best.To sum up this paper focuses on the optimization and allocation of network available energy resources.Based on the nonlinear model,it combines SWIPT with OFDM and multi-antenna technology.First,this paper proposes a joint subcarrier and power allocation algorithm for two-way SWIPT networks.The proposed algorithm,which is neither dependent upon the power splitting nor the time switching schemes and simplifies the design of SWIPT principles,transfers information and energy using different subcarriers.Considering the saturation characteristic of actual EH circuit,the joint design algorithm,which is developed by using lagrange dual and subgradient methods and thus is based on the nonlinear energy harvesting model,is formulated to minimize the energy consumption of networks under condition that the required rate of the destination is satisfied.Simulation results shows that the algorithm is effective and energy efficient.Then,the application of multi-antenna technology in OFDM SWIPT network is further studied.Based on artificial noise and nonlinear energy collection model,a novel dual power-splitting receiver architecture is proposed.A network throughput maximization problem is formulated by jointly optimizing the variables including the transmitting beamforming vectors,the AN covariance matrix,the PS ratios and the number of split streams,and by satisfying these constraints including the required harvested energy of the legitimate receivers,the secrecy signal-to-interference-noise ratio,and the total available power limit at the base station.In order to solve the formulated non-convex problem,a bisection method based on the semidefinite relaxation was proposed to solve the problem,and is used to optimally distribute the network resources.The simulation results validate the proposed algorithm's effectiveness.Compared with others receiver architecture,the proposed dual PS receiver maintains higher network throughput.