Robust Secure Precoding and Antenna Selection: A Probabilistic Optimization Approach for Interference Exploitation

In this paper, to realize a power-efficient, user-centric and physical layer security-addressing system, we investigate total power minimization by jointly designing antenna selection and secure precoding for distributed antenna (DA) systems. Different from the conventional artificial noise (AN)-aided secure transmission, where AN is treated as an undesired element for the intended receiver (IR), we design AN such that it is constructive to the IR while keeping destructive to the eavesdroppers (Eves). Importantly, we investigate a practical scenario, where the IR and Eves' channel state information (CSI) is imperfectly obtained. To handle the CSI uncertainties, we solve the problem in a probabilistic manner, which statistically satisfies the IR' signal-to-interference-and-ratio (SINR) requirement by use of constructive AN and addresses security against the Eves. Simulation demonstrates our algorithm consumes much less power compared to the centralized antenna (CA) systems, as well as the DA systems with conventional AN processing. Last but not least, a user-centric and on-demand structure is presented by the algorithm, thanks to the adaptive DAs activation/deactivation mechanism.