Intelligent Reflecting Surface Assisted Secrecy Communication via Joint Beamforming and Jamming

In this letter, we investigate an intelligent reflecting surface (IRS) assisted wireless secrecy communication system, where an IRS is deployed nearby a single-antenna receiver to assist in the secure transmission from a multi-antenna transmitter, in the presence of multiple single-antenna eavesdroppers. Aiming to maximize the achievable secrecy rate, a design problem for jointly optimizing transmit beamforming with jamming and IRS reflect beamforming is formulated, which is however difficult to solve due to its non-convexity and coupled variables. We thus propose an efficient algorithm based on alternating optimization to solve the problem sub-optimally. Simulation results show that incorporating jamming with artificial noise (AN) in transmit beamforming is generally beneficial to improve the secrecy rate, even under the new setup with IRS reflect beamforming.