Cognitive multiple access networks

A cognitive radio can sense the transmission of other users in its environment and possibly extract the corresponding messages. It can use this information to transmit over the same channel while reducing interference from, and to other users. In this paper, we define inter/intra-cluster competitive, cooperative, and cognitive behavior in wireless networks. We define intercluster cognitive behavior as simultaneous transmissions by two or more clusters in which some clusters know the messages to be transmitted by other clusters, and so can act as relays or use a Gel´fand-Pinsker coding-like technique to mitigate interference. We construct an achievable region for the inter-cluster behavior of two multiple access channels. In the Gaussian case, we compare our achievable region to that of competitive behavior as well as that of cooperative behavior