Research On Cooperative Jamming And Resource Allocation In Energy Harvesting Relay Networks

With the increasing demand of wireless communication network for information transmission security and low energy consumption,cooperative communication technologies and SWIPT are attracting more and more attention.The transmission of radio frequency signals can be eavesdropped by illegal users,so that the security of communication cannot be guaranteed.At the same time,to solve the problem of energy consumption of wireless devices,introduced SWIPT make these devices have stronger endurance.Secure transmission strategies in energy harvesting relay networks are studied and the main work is summarized as follows:A two-way untrusted multi-relay network model based on linear energy harvesting and imperfect channel state information,a cooperative interference strategy based on two sources is proposed,and the secrecy rate expression for two-way untrusted multi-relay network is derived.Under the condition that the transmit power is constrained,a joint power allocation and time switching scheme is studied to maximize the secrecy rate.The optimal power allocation factor and time switching factor are determined by genetic algorithms.At the same time,the joint power allocation and time switching scheme with independent power constraints and the power allocation scheme with equal time allocation are also studied.For the convex optimization problem of the joint power allocation and time switching scheme under independent power constraints,the optimal solutions are obtained by the block coordinate descent method.The simulation and analysis of the three schemes were carried out.Under the condition of the default parameters,compared with the other two schemes,the secrecy rate of the proposed scheme is 0.8285 b/s/Hz,which achieve better secrecy performance.For the one-way relay network based on nonlinear energy harvesting and imperfect channel state information,a cooperative interference strategy based on the destination node is proposed,and the expression of the secrecy rate of the one-way energy harvesting relay network is derived.Under the total power constraint and with the goal of maximizing the system secrecy rate,a joint power splitting and time switching scheme based on nonlinear energy harvesting is studied.The optimal power splitting factor and time switching factor are obtained by interior point method.At the same time,the existing power splitting scheme and time switching scheme are simulated and analyzed.Experimental results show that the proposed joint power splitting and time switching scheme has a better secrecy rate than the comparative scheme.Under the condition of default parameters,compared with the other two existing schemes,the secrecy rate of the proposed scheme is 2.0149 b/s/Hz,which achieve better secrecy performance.