On feasibility of interference alignment and cancellation for Gaussian interference multiple access channel

The feasibility condition for interference alignment (IA) with no channel extension has not been known yet. In this paper, for the first time, we explore the feasibility of interference alignment and cancellation (IAC) which has been proposed for IA with no channel extension. We investigate IAC for the Gaussian interference multiple access channel (MAC) with K receivers and J users, each with M antennas. We establish and prove the general feasibility conditions of IAC. A graph theoretic approach is central to the results.