Intelligent Omni-Surface Assisted Physical Layer Security Communication

This paper investigates the secrecy transmit power optimization problems for an Intelligent Omni-surface (IOS) aided communication system under energy-limited conditions. We formulate the power minimization problem based on the assumption that the Base Station (BS) has statistical channel state information (CSI) of the eavesdroppers, where the optimization problem is non-convex because of intertwined active and passive beamforming vectors and non-convex secrecy outage probability constraints. With the aid of Bernstein-type inequality and semi-definite relaxation, we first reformulate the original problem into the active and passive beamforming subproblems, and then propose a robust joint beamforming design that solves these two subproblems in an alternating way. The convergence and complexity of the proposed algorithm are then analyzed, and simulation results verify the performance of the algorithm.