Unequal Secrecy Protection for Untrusted Two-Way Relaying Systems: Constellation Overlapping and Noise Aggregation.

This paper studies the secure information exchange of two-way relaying systems, where two terminal users communicate bi-directionally with the assistance of an untrusted relay. Each user is assumed to have two messages with distinct priorities: high priority and low priority. The high-priority messages (HPM) are first transmitted, for which we propose a constellation overlapping scheme such that t...