Research On Radio Frequecv Energy Havesting Technology In Collaborative Communications

With the advent of the fifth generation mobile communication networks where high transmission,low latency and massive equipment access,radio frequency(RF)energy harvesting(EH)technology will be widely used in terminal equipment in the future,which can reduce the carbon of wireless communication networks,extend the life cycle of equipment and ensure the sufficiency of power supply in system.In addition,cooperative communication technology is an effective way to improve the capacity,coverage and diversity performance of wireless communication systems,and is also a powerful means to solve the double far and near benefit problem of long-distance with multi-users.However,the collaborative communication scenario and mode make the radio frequency energy harvesting networks more complicated,and also challenge resource allocation and transmission scheme design.Therefore,the main research points of this paper on RF EH technology in cooperative communication are summarized as follows:Firstly,we have introduced the background of RF EH technology and the current research of the combination of RF EH and cooperative communication in detail.Then,the basic model of cooperative communication and three forwarding protocols is briefly introduced and two key technologies of wireless power transmission:simultaneous wireless information and energy transfer(SWIPT)and wireless power communication networks(WPCN)are investigated on system models and transmission principle.Further,the current research of WPCN networks and SWIPT networks at home and abroad is investigated,focusing on the research combined with cooperative communication scenarios.Then,we have studied the design of full-duplex WPCN with joint transceiver based on user cooperation.Based on full duplex WPCN with dual-user cooperative scenario,a shared channel scheme and a low complexity algorithm are proposed.Adopting the amplifying and forwarding protocol,the system achieves uninterrupted information transmission and self-energy recovery,by j ointly designing the energy and information beamforming of the transceiver in the system.In addition,the zero-forcing method is applied to eliminate the self-interference of the joint transceiver.At last,the low-complexity algorithm is adopted for the quasi-convex optimization problem to maximize the system capacity.Compared with the other three optimization schemes,the trend of maximizing the capacity of the proposed scheme is simulated.The results show that the proposed scheme can effectively improve the energy transmission efficiency and system capacity,and the performance gain increases with the number of antennas.Finally,we have studied the resource allocation in multi-user broacasting SWIPT cooperative communication networks based on non-linear EH model.For the SWIPT multi-user cooperation scenario,the optimal energy allocation strategy based on Time Switching(TS)receiver and Power Splitting(PS)receiver is proposed by using nonlinear energy harvesting model.The system introduces an exponential nonlinear energy harvesting model,and uses the Lagrangian dual method and the binary search method to obtain the global optimal solution of the distribution parameter.Under the TS and PS receivers,we simulate rate-energy domain of the multi-user interference network under different parameters of the nonlinear model,and then compare the balance performance of the system under three different interference intensities.Simulation results show that as the information rate increases,the decline rate of the energy in the energy system decreases first and then increases.The nonlinear energy harvesting model is superior to reflect the actual energy harvesting circuit structure.