Intelligent Reflecting Surface: A Programmable Wireless Environment for Physical Layer Security

Understand

In this paper, we introduce an intelligent reflecting surface (IRS) to provide a programmable wireless environment for physical layer security.

• By adjusting the reflecting coefficients, the IRS can change the attenuation and scattering of the incident electromagnetic wave so that it can propagate in a desired way toward the intended receiver.
• Specifically, we consider a downlink multiple-input single-output (MISO) broadcast system where the base station (BS) transmits independent data streams to multiple legitimate receivers and keeps them secret from multiple eavesdroppers.
• By jointly optimizing the beamformers at the BS and reflecting coefficients at the IRS, we formulate a minimum-secrecy-rate maximization problem under various practical constraints on the reflecting coefficients.