Researchs On Interference Management Technologies Of Secure Cooperative Transmission In Cognitive SWIPT Networks

Cognitive simultaneous wireless information and power transfer(SWIPT)networks combine SWIPT and cognitive radios network(CRN),which aims to improve energy efficiency and spectral efficiency simultaneously.However,it also induces some problems,such as how to cancel interference and ensure secure information transmission in cognitive SWIPT networks.The traditional interference management technology aligns the interference to the orthogonal information subspace to cancel interference.SWIPT receiver uses interference alignment(IA)technology,which not only eliminates interference but also uses interference as energy source in cognitive SWIPT network.Meanwhile,aiming at the security problem in cognitive SWIPT network,receiver induces artificial noise and beamforming vector to reduce the communication quality at eavesdropper.This dissertation investigates interference management technologies of secure cooperative transmission in cognitive SWIPT networks.The dissertation studies different interference management strategies and secure transmission strategies in different cognitive SWIPT network scenarios.The main research aspects of this dissertation are shown as below.1)An enhanced maximum signal to interference plus noise ratio(MAX-SINR)strategy is proposed with interference leakage power constraint,which realizes a tradeoff between information transmission and interference leakage in multiuser multiantenna SWIPT systems.Optimization problem is formulated and a three-step optimization solution is proposed.Finally,the problem is transformed into a standard semi-definite programming(SDP)to obtain optimal power splitting factor and system sum-rate.Simulation results are presented to show that system sum-rate performance is enhanced with the increasing of receiving antenna numbers.The tradeoff between sum-rate and the harvested energy can be realized via the proposed IA strategy.2)The spectral efficiency optimization problem based on MAX-SINR interference alignment is investigated in cognitive MIMO SWIPT network.In order to maximize the spectral efficiency,the interference power is optimized on the basis of ensuring the primary network with transmission power optimization.A pair of relays are selected to forward information.The spetral efficiency of cognitive network is improved by optimizing power splitting factor and applying MAX-SINR technology on the constraint of the information transmission rate and energy harvesting constraints.3)A cognitive SWIPT secure transmission strategy based on artificial noise assistance and MAX-SINR interference alignment strategy.Considering the security rate of the primary network with eavesdropper in the cognitive SWIPT network,it aims to maximize the security rate of the primary network by joint designing the beamforming vector,artificial noise interference and power splitting factor.Meanwhile,MAX-SINR technology is applied to eliminate interference in the cognitive network,which further optimizes the spectral efficiency of the cognitive network.This dissertation studies research on interference management technologies of secure cooperative transmission in cognitive SWIPT networks and the research achievements provide significant value for the further related works.