Optimal transmission scheduling of cooperative communications with a full-duplex relay

Most existing research studies in cooperative communication are based on a half-duplex assumption. Motivated by recent successes in hardware implementation of wireless full-duplex transmission, we propose a full-duplex cooperative communication (FDCC) approach to maximize the minimum transmission rate among a set of users to a common destination with the help of a dedicated relay. Under the consideration of hardware cost, only the relay node requires full-duplex wireless equipment in our design. We derive the achievable transmission rate for the proposed FDCC scheme under both amplify-and-forward (AF) and decode-and-forward (DF) modes. Further, as the transmission scheduling of users plays a critical role in determining the achievable transmission rate in FDCC, we formulate the max-min rate scheduling problem as a nonconvex mixed integer nonlinear programming (MINLP) problem. By applying linearization and convex approximation techniques, we propose an optimal algorithm based on a branch-and-bound framework to solve the problem efficiently. Extensive simulation results show that FDCC can significantly improve the transmission rate as compared with direct transmission and half-duplex cooperative communication (HDCC).