Joint Opportunistic Scheduling and Network Coding for Bidirectional Relay Channel
In this paper, the authors consider a two-way communication system in which two users communicate with each other through an intermediate relay over block-fading channels. They investigate the optimal opportunistic scheduling scheme in order to maximize the long-term average transmission rate in the system assuming symmetric information flow between the two users. Based on the channel state information, the scheduler decides that either one of the users transmits to the relay, or the relay transmits to a single user or broadcasts to both users a combined version of the two users' transmitted information by using linear network coding. They obtain the optimal scheduling scheme by using the Lagrangian dual problem.