Research On Wireless Network Transmission Strategy Based On Wireless Power Transfer

Over the past two decades,the field of wireless communications has made tremendous progress,but with the dramatic increase in computing tasks and data volumes,battery capacity begins to limit the development of wireless communications.Therefore,wireless power transfer(WPT)using radio frequency signals emerges as an innovative technology,which is mainly used to improve the limited life of energyconstrained wireless devices.At the same time,energy and information are combined and transmitted through radio frequency signal,that is,simultaneous wireless information and power transmission(SWIPT)is generated.It enables energy-deficient nodes to decode information and harvest energy simultaneously,which is helpful for a large number of low-power wireless devices to communicate and harvest energy anytime and anywhere.In addition,the emergence of a series of emerging communication technologies also provides new ideas for the development of wireless communication.Therefore,based on WPT and SWIPT system,combined with other emerging communication technologies,the research on system performance improvement is of great significance.Firstly,the combination of mobile edge computing(MEC)and WPT can enable the system to provide sustainable energy supply and computing services at the edge of the network.The application of non-orthogonal multiple access(NOMA)in the offloading process can improve the efficiency and spectrum utilization of multi-user unloading.Therefore,a NOMA aided three node WPT-MEC model is established,and the user cooperation is used to effectively solve the dual-near-far effect.Based on the proposed model,the closed-form solution of each optimization variable is obtained by Lagrange dual method,and the proposed user energy consumption minimization problem is solved by iterative optimization algorithm.Secondly,in order to improve the channel conditions in SWIPT system and significantly reduce energy consumption and hardware cost,intelligent reflecting surface(IRS)is proposed to be applied to the first hop and the second hop of SWIPT cooperative relay system respectively,and the system is modeled.In addition,two transmit power allocation strategies are proposed,and the optimal value method of variables under the two strategies is derived.Finally,the performance of the four schemes is analyzed.The transmit power,power splitting ratio,different power allocation strategies and IRS deployment location of access point(AP)and relay are studied,and the optimal IRS deployment scheme is proposed.Finally,in order to improve the security of users in the SWIPT system,and enable users to decode information and harvest energy simultaneously,it is proposed to use IRS technology in the SWIPT system with additional eavesdroppers,in which users use power splitting technology and transmit additional artificial noise(AN)at the AP.Based on the proposed model,under the guarantee of reaching the minimum threshold of user harvested energy and the limitation of AP transmit power,the corresponding iterative optimization algorithm is established by using Taylor formula,semi-definite relaxation and alternating optimization to solve the proposed user achievable security rate maximization problem,and its simulation verification is carried out.