CTH17-5: Multiple Relay Channels with Asymmetric Transmit Side Information

In this paper we investigate the effect of asymmetric side information in discrete memoryless relay channels. The capacity of the degraded relay channel is known when side information at both the source and relay is identical. However, in many naturally interesting cases the source and relay may not have, or may not be able to exploit, exactly the same side information. This may occur either when side information is privileged information that is available only at one of the nodes (e.g. watermarking problems) or when the relay does not have the ability to collect or utilize full information about channel state and/or interference. In this paper we calculate capacity expressions for degraded discrete memoryless relay channels where the source and relay do not have identical side information. As a special case we consider the case where the relay has no side information. We consider causal as well as non-causal side information, and show an upper bound for the difference between capacities for various cases.