This paper investigates simultaneous wireless information and power transfer (SWIPT) for a multiple-input-singleoutput (MISO) secrecy channel. First, transmit beamforming without artificial noise (AN) is designed to achieve the secrecy rate maximization problem subject to the transmit power and the energy harvesting (EH) constraints. This problem is not convex, but this can be solved by applying a bisection search to a sequence of the associated power minimization problems, each of which can be solved by using a novel relaxation approach. Moreover, we extend our proposed algorithms to the robust case by incorporating channel uncertainties. Then, transmit beamforming with AN is investigated for the secrecy rate maximization problem, where two relaxation approaches are presented, i.e., a two-level optimization algorithm and a successive convex approximation (SCA), to solve the secrecy rate maximization problem. In addition, tightness analyses of rank relaxation are provided to show that the optimal transmit covariance matrix exactly returns rank one. Simulation results are provided to validate the performance of the proposed algorithms. Index Terms-Bisection method, multiple-input-single-output (MISO) system, physical-layer secrecy, simultaneous wireless information and power transfer (SWIPT), successive convex approximation (SCA). E NERGY harvesting (EH) has been proposed in fifthgeneration (5G) wireless communication networks to circumvent the issue of energy limitations in mobile devices and improve the energy efficiency of these networks by extracting energy from the external natural environment (e.g., solar power, wind energy, etc.) [1], [2] . Traditionally, energy is directly harvested from external sources without exploiting the resources of the communication network itself. However, when the natural environment is not able to provide stable energy, wireless mobile receivers have to find an alternative energy source in the communication network. This source can be the information-carrying radiofrequency (RF) signal radiated by the fixed transmitters (base Manuscript
In REF , the secure beamforming with and without artificial noise (AN) are designed for the SWIPT system with multiple ERs and eavesdroppers considering both perfect and imperfect CSI at the transmitter, and a novel bisection search based reformation is proposed to transform the secrecy rate maximization problem into a sequence of the associated power minimization problems.
Simultaneous Wireless Information Power Transfer for MISO Secrecy Channel
IEEE Transactions on Vehicular Technology
IEEE Transactions on Vehicular Technology
Computer Science Mathematics