Research On Energy Efficiency And Transmission Security Of Full Duplex Heterogeneous Cellular Network With Swipt

Wireless communication is booming,and so is the number of wireless devices connected to the network.The requirements for network performance such as transmission rate,network coverage,and communication security are increasing.However,the shortage of energy and spectrum resources has severely restricted the improvement of network performance.It is an urgent issue to solve the contradiction between them for now.The multi-layer,three-dimensional heterogeneous cellular network composed of different types of access points and the full-duplex technology with the ability to send and receive RF signals using the same frequency at the same time are very helpful to improve network capacity and spectrum utilization.These technologies are considered to be very effective ways to deal with the surge of traffic.Simultaneous wireless information and power transfer can also make full use of precious transmit power to transmit energy while transmitting information.It is a promising solution to truly realize the green and sustainable operation of wireless devices.The continuous improvement of the requirements for communication quality of service has led to a continuous increase in energy consumption.In order to meet the "green" and secure communication requirements,this article analyzes and discusses the performance of simultaneous wireless information and power transfer technology and full duplex technology in heterogeneous cellular networks from the perspective of energy efficiency optimization and physical layer security.The main research work is summarized as follows:(1)Aiming at the energy efficiency optimization problem of the proposed communication networks,a sub gradient optimization algorithm based on Dinkelbach and Lagrange duality principle was proposed.While meeting the transmission power threshold constraints and the quality of service requirements of microcell and femtocell,the energy efficiency of femtocell is maximized through reasonable and effective resource allocation.In order to solve this nonconvex fractional programming problem,Dinkelbach method was used to transform the original fraction problem,then Lagrange duality principle and double cycle variable method were used to decouple the two optimization variables and transform them into two equivalent sub-problems,and finally the sub-gradient iterative algorithm was used to solve the sub-problems iteratively.Simulation experiment results demonstrate the feasibility and effectiveness of the proposed full-duplex system with self-energy recovery and resource allocation algorithm.(2)Considering that the system proposed in this paper is a multi-user scenario and the wireless channel is open,the security of legal user confidential information transmission is particularly important.Therefore,the communication security problem when there are multiple eavesdropping nodes is further considered in this chapter.Then an artificial noise-assisted beamforming design scheme is proposed from the perspective of physical layer security.The transmission security problem is modeled as the secure energy efficiency maximization problem of the system.Under the constraints of safe transmitting power threshold,minimum secure rate and energy harvesting,a double-layer optimization algorithm based on Dinkelbach and successive convex approximation was proposed to maximize the secure energy efficiency by jointly optimizing artificial noise and information signal beamforming vector as well as UL transmitting power.The simulation experiments verify the effectiveness of the proposed double-layer resource allocation optimization algorithm,and also prove the feasibility of full-duplex and artificial noise in improving system security and energy efficiency.Finally,the research of this paper is summarized,and the possible development direction of wireless communication network in the future is forecasted.