A Novel Rateless Coded Protocol for Half-Duplex Relaying Systems with Buffered Relay

In this paper, we consider a half-duplex decode-and-forward (DF) relaying system with rateless codes and buffered relay. Invoking rateless codes, both the source and the relay can automatically adapt their transmission rates according to the instantaneous channel state information (CSI). Furthermore, the buffered relay provides flexibility for realizing opportunistic relaying based on the CSI of the source-relay and the relay destination links. For a given relaying decision function, we successfully derive the optimal opportunistic rateless coded relaying protocol and analytically obtain the corresponding throughput. Numerical results verify our analyses and show a significant improvement compared to the conventional non-buffered relaying protocol.