Relay Channel with Causal Channel State Information

In this paper, the problem of state dependent relay channel (SD-RC) with causal channel state information (CSI) is considered. Two different cases are investigated in which causal CSI is available: 1) only at the relay node, 2) at all the nodes. And the second situation is further specialized to cases in which causal CSI is available: at both the source and relay; at both the destination and relay. For the relay with causal CSI, we don't only use Shannon strategy as previous work. In our scheme, the causal CSI is compressed and transmitted with the message information. The inner bound of our scheme contains all bounds in previous work and outperforms in some cases. For the second case, we discuss the strategy of the source and destination when they are accessed with causal CSI, and give corresponding results.