Outage Constrained Robust Secure Transmission for MISO Wiretap Channels

TL;DR

This paper develops a robust beamforming method for MISO wiretap channels that maximizes secrecy rate while satisfying outage probability constraints, ensuring secure communication under channel uncertainties.

Contribution

Introduces a novel two-step algorithm for outage-constrained robust beamforming, capable of achieving high-quality or exact solutions under various uncertainty models.

Findings

Algorithms effectively maximize secrecy rate under outage constraints

Proposed methods demonstrate robustness in simulations

Some solutions are globally optimal

Abstract

In this paper we consider the robust secure beamformer design for MISO wiretap channels. Assume that the eavesdroppers' channels are only partially available at the transmitter, we seek to maximize the secrecy rate under the transmit power and secrecy rate outage probability constraint. The outage probability constraint requires that the secrecy rate exceeds certain threshold with high probability. Therefore including such constraint in the design naturally ensures the desired robustness. Unfortunately, the presence of the probabilistic constraints makes the problem non-convex and hence difficult to solve. In this paper, we investigate the outage probability constrained secrecy rate maximization problem using a novel two-step approach. Under a wide range of uncertainty models, our developed algorithms can obtain high-quality solutions, sometimes even exact global solutions, for the robust secure beamformer design problem. Simulation results are presented to verify the effectiveness and robustness of the proposed algorithms.