| The arrival of the 5G wireless communications has brought new challenges to traditional energy-constrained wireless networks.Based on the user’s requirements,in addition to the performance of the experience rate increase by a thousand times,and the delay is reduce to millisecond level.In terms of spectrum efficiency and energy efficiency,it will be tens or even hundreds of times higher than the traditional wireless network,so as to realize green communication.Energy harvesting technology can harvesting energy via ambient radio frequency(RF),and use it for subsequent wireless communication.Thus prolonging the lifetime of system and improving the performance of the wireless networks in terms of reducing energy consumption and charging cost.There are currently two main approaches to energy harvesting:(i)wireless powered communication networks(WPCN)and(ii)simultaneous wireless information and power transfer(SWIPT).On the other hand,the adoption of new technologies such as mm Wave communication and D2 D communication can improve the performance of wireless network in terms of improving spectrum efficiency and system throughput.Therefore,this paper considers the application of energy harvesting technology in D2 D and mm Wave communication to improve network performance in terms of improving spectrum efficiency and energy efficiency.Main research works are as follows:(1)For 5G edge network,based on the WPCN working mode,the SWIPT technology was applied to the downlink transmission of a WPCN communication cycle in this paper.We established a new small cell network model of user equipment devices(UEs)and mm Wave cooperative communication for high-low frequency hybrid networking.This model used power beacons(PBs)to replace the conventional base station(BSs)to provide energy supply for the energy-constrained UEs,and applied the directional transmission technology of the communication mm Wave to the process of building the chain by designing a new “Build to Order(BTO)” protocol.(2)Aiming at the optimization problem of energy harvesting phase,in order to improve the spectrum efficiency and reduce energy consumption of edge system,an optimized deployment strategy of small cell wireless power beacon based on 5G mm Wave cooperative communication was proposed.By minimizing the number of PBs in fixed charging,the strategy ensures the normal operation of the system on the basis of minimizing the energy consumption of the system.Since this problem is a mixed integer programming problem and NP-hard,a greedy algorithm with constant factors was designed to solve the optimization problem approximately.Theoretical analysis proves the feasibility of the algorithm.The simulation results show that the proposed strategy can effectively optimize the PBs deployment,and the energy consumption is the lowest under the same coverage and regional spectrum efficiency gain.(3)Aiming at the optimization problem of SWIPT phase,an optimal energy efficiency strategy based on mm Wave cooperative communication small cell under SWIPT was proposed to maximize the link energy efficiency,in which the receiver of UE worked in the power splitting mode.Under the constraints of minimum link transmission rate and minimum energy harvested,the strategy maximized the link energy efficiency of the system by jointly optimizing the transmitting power control and the power splitter factor.Since this problem is a nonconvex fractional programming problem and NP-hard,we transformed the original problem into a tractable convex optimization problem which is easy to solve by using by using Dinkelbach method.Then Lagrange dual method was used to solve the problem,and finally a cross-iteration algorithm was designed to get the optimal solution.Simulation results show that the proposed strategy is compared with the traditional power control method and the maximum transmitting power method,and prove the effectiveness and superiority of the proposed scheme.From the perspective of improving the spectral efficiency and energy efficiency of 5G wireless network,this paper proposes an edge network structure model suitable for 5G demand.The optimal deployment strategy of wireless power beacons and the optimal link energy efficiency strategy based on the model provide a solution for the optimization of system energy consumption in 5G communication network energy management,which has certain scientific significance,academic significance and application value. |
