| Either the security transmission of information or the energy consumption of systems is investigated in traditional physical security communication.It is of great significance to seek effective ways to balance them because of their conflicting performances and the fact that it is more and more difficult to meet people’s high requirements of the wireless communication system,including the following aspects:Firstly,the optimization of the transmit power and the secrecy rate jointly is considered in a multiple-input-single-output(MISO)downlink network in this paper.A multi-objective optimization(MOO)framework based on the weighted Tchebycheff approach is proposed to transform the two conflicting single-objective problems into a multi-objective problem.The transmit power and the secrecy rate are balanced designed by optimizing jointly the precoding matrix and artificial noise(AN)covariance matrix.Then,simulation results demonstrated the effectiveness of the proposed design.Secondly,a downlink multiuser MISO network is researched considering the reality.Taylor series expansion is then employed to recast the formulated multi-objective optimization problem(MOOP)as a linear one.S-Procedure and Cauchy-Schwarz inequality are applied to deal with the Semi-infinite constraints.Finally,a robust iterative algorithm is proposed to achieve the Pareto optimal boundary under the assumption that the channel state information(CSI)is not perfectly known at the transmitter.Simulation results not only demonstrate the convergence of the proposed algorithm,but also indicate the effectiveness of it with large channel error compared with traditional nonRobust one.Finally,the secure transmit design for a communication system based on simultaneous wireless information and power transfer(SWIPT)is studied in order to utilize the harvested energy.The optimal transmission strategy is proposed by optimizing jointly the precoding matrix,AN covariance matrix and power splitting ratio.Simulation results unveil the trade-off between the transmit power and the secrecy rate. |
