On the asynchronous cognitive MAC

Abstract

We introduce the asynchronous cognitive multiple-access channel with an uninformed encoder and an informed one. We assume that the informed encoder knows in advance the message of the uninformed encoder and consequently its codeword, up to some delay. In addition, the informed encoder knows the set of all possible delays in the channel. We characterize the capacity region of the ACMAC in terms of multi-letter expressions. In addition, we present single-letter inner and outer bounds on the capacity region of this channel. We conclude by studying the special case of the Gaussian asynchronous multiple-access channels with an uninformed encoder.