Interference Alignment in the 2 x (1+N) MIMO Model

In modern cellular systems, base station cooperation multiple-input multiple-output (MIMO) in which multiple base stations transmit desired signals to one user is anticipated to alleviate interference at the cell-edge. Cell-edge user is influenced a great deal by interference between different base stations. Inter-cell interference degrades system performance substantially. An interference alignment (IA) scheme was proposed recently to eliminate inter-cell interference. It aligns interference into a smaller-dimensional subspace to eliminate interference. In this paper, we clarify how to apply IA to the 2 base stations (BSs) x (1 + N) mobile stations (MSs), 2 <= N < infinity, MIMO model, where one MS, referred to as Cooperated Mobile Station (CMS), is transmitted with two BSs simultaneously, and others, referred to as non cooperated mobile stations (NMSs), are transmitted with one BS. We show that IA is effective to reduce interference at CMS, while achieving the higher capacity than the conventional one through computer simulation.