Research On Optimization Of Resource Scheduling Strategies In Energy-efficiency Priority Based Cognitive SWIPT Network

Cognitive simultaneous wireless information and power transfer(SWIPT)communication network combines cognitive radio network(CRN)and SWIPT technology.CRN aims to enhancing spectral-efficiency,while energy-constrained SWIPT nodes harvest energy from radio frequency(RF)signals,which overcomes the drawback of dependence on battery power and prolongs the node life cycles.Hence,SWIPT guarantees energy-efficiency.However,due to the characteristics of broadcasting in wireless channel,eavesdropper attack often occurs in cognitive SWIPT network,which induces network security problem.Therefore,how to design and optimize resource allocation and scheduling strategies on the premise of ensuring security in cognitive SWIPT network,is of great significance in improving spectral-efficiency and guaranteeing energy-efficiency.This dissertation investigates three research parts in cognitive SWIPT network.Namely,uplink and downlink joint resource allocation strategy based on generalized frequency division multiplexing(GFDM)in cognitive SWIPT,multi-relay time and power joint optimization scheme based on dynamic time power splitting(DTPS)protocol and energy-efficiency priority based secure cooperative transmission and resource scheduling strategy in the presence of eavesdropper in cognitive SWIPT.Specific research parts are shown as below.1)Generalized frequency division multiplexing(GFDM)based uplink and downlink joint resource allocation strategy in cognitive SWIPT is poposed.The weighted uplink and downlink achievable sum rate is maximized in the constrained conditions of harvested energy and total transmission power via the joint GFDM subcarrier and subsymbol allocation,power and PS factor assignment in the uplink and downlink channel.In order to solve this non-convex optimization problem,Lagrangian dual method,sub-gradient method and greedy algorithm are implemented respectively.2)multi-relay time and power joint optimization strategy is investigated based on dynamic time power splitting(DTPS)protocol in cognitive SWIPT.The proposed scheme joint optimizes power splitting(PS)factor,time switching(TS)factor and power allocation coefficient.System performance meets the requirements via the best relay selection and the joint optimization of PS factor,TS factor and power allocation coefficient for the best relay.3)Energy-efficiency priority based secure cooperative transmission and resource scheduling strategy in the presence of eavesdropper are studied in cognitive SWIPT.With the joint optimization of beamforming vector and PS factor design for cognitive SWIPT relay,it is possible to achieve the maximum secure communication rate bwtween primary network and cognitve network with energy-efficiency priority.The dissertation conducts a preliminary study on optimization of resource scheduling strategies in energy-efficiency priority based cognitive SWIPT network.Research achievements provide significant values for the further related works.