Interference Alignment by Opportunistic User Selection in 3-User MIMO Interference Channels

In this paper, we propose a practical interference alignment technique based on an opportunistic user selection in a three-user MIMO interference channel where no information is allowed to be shared among transmitters. In the proposed scheme, the user whose interference signals from other transmitters are most aligned with each other is selected at each transmitter. The proposed opportunistic interference alignment (OIA) is shown to achieve notable sum rate compared to conventional opportunistic user selection schemes. In addition, the proposed OIA significantly reduces not only the amount of feedback information but also computational complexity.