Stability Region of an Efficient Bidirectional Regenerative Half-duplex Relaying Protocol

In this work, a stability optimal rate allocation policy for two M/G/1-¿ queues in a three node scenario with peak power constraints is characterized in closed form. Between two nodes, bidirectional communication is realized by a half-duplex decode-and-forward relay node. A centralized controller adapts slotwise the optimal discrete-time resource allocation according to the block-fading channel and queue state. In the memoryless Gaussian multiple access mode, the two nodes transmit their information to the relay node. In the memoryless Gaussian broadcast mode, the relay node forwards both information to their destinations. Since each destination node knows its own interference, efficient re-encoding increases the achievable broadcast rates. It results from "standard" Lyapunov drift technique that the stability region facilitated by the proposed rate allocation policy is equal to the ergodic achievable rate region.