An information theoretic study of time-division wireless relay channels

This paper studies upper bounds and lower bounds on the ergodic capacity of a three-node wireless relay channel in a Rayleigh fading environment. We take into account practical constraints on the transmission duplexing at the relay node and on the synchronization between the source node and the relay node. We find that the gap between the upper bounds and lower bounds is typically negligible. Compared to direct transmission and traditional multi-hop protocols, our results reveal that optimum relay channel signaling can significantly outperform multi-hop protocols, and that power allocation has a significant impact on the performance.