We consider the inter-cluster cognitive behavior of two dissimilar interfering clusters, where the first cluster (i.e. primary cluster) consists of a broadcast channel (BC) which has a single sender and two receivers and the second cluster (i.e. cognitive cluster) is a single multiple access channel (MAC) with two senders and one receiver. The MAC is assumed to have cognitive transmitters, who know the message transmitted by the other noncognitive broadcast transmitter, in a non-causal manner. A Gel’fand-Pinsker coding-like technique is used to mitigate intercluster interference. First, an achievable rate region for this model is derived based on the Marton with common message region for the general BC and using a result of Slepian-Wolf rate region for the MAC. Then by using the rate region of the second cluster, we obtain the achievable rate region for the two-user MAC with common message and common side information known noncausally at the transmitters and show that the obtained achievable rate region is optimal when common side information is known at the receiver as well.

Keywords