Research On Energy Efficient Optimization Algorithm For IRS-Assisted Secure Comunication Networks

Recently,with the comprehensive application of network technology,the number of smart devices has proliferated,which makes the requirements of wireless communication systems further improved.The system should not only satisfy the quality of service(Qo S)for users,but also enhance the sustainability of the equipment.To reduce the construction cost and energy consumption,intelligent reflecting surface(IRS)is studied deeply as an effective solution,which has the advantage of low cost and low energy consumption.In addition,due to the introduction of various wireless access methods,information leakage in communication is caused.And IRS can improve the security of user communication through phase adjustment.As a result,this thesis aims to optimize the energy efficiency in IRS-assisted secure communication system.The specific research contents are summarized as follows.1.To enhance the total energy efficiency of system users,the energy efficiency maximization resource allocation for IRS-aided wireless communication networks based on the perfect channel state information(CSI)case is studied.Firstly,under the multiple input single output(MISO)cellular communication networks,the model of maximizing the total energy efficiency of the system users is established.Secondly,due to the original non-convex problem,the fractional programming problem is transformed into a subtraction parameter form by dinkelbach method.And the strongly coupling variables of transmit beamfrming and IRS phase-shift are decoupled by alternating optimization(AO)algorithm.Finally,a resource allocation algorithm to maximize the total energy efficiency of the system is proposed.The simulation results show that the proposed algorithm has better energy efficiency while ensuring the safe communication of users.2.In order to keep the sustainability of the mobile devices and improve the robustness of the system,the energy efficiency optimization resource allocation for IRSaided simultaneous wireless information and power transfer(SWIPT)networks is studied,which is based on the imperfect CSI case.Firstly,under the MISO cellular communication networks,a robust resource allocation model for the maximum total energy efficiency of the system is established.Secondly,the Dinkelbach method and Sprocedure method are used to deal with the fractional programming problem and the parameter uncertainty constraints of the eavesdropping channel,respectively.Thirdly,the first order Taylor expansion formula is used to approximate the difference of convex programming form in the objective function.Finally,an AO algorithm based on successive convex approximation is proposed.The simulation results show that the proposed algorithm has good robustness and energy efficiency.