On Achieving Optimal Degrees of Freedom of MIMO Cellular Networks Using Decomposition

Abstract—This paper investigates the significance of decomposition-based schemes in achieving the optimal degrees of freedom (DoF) of multiple-input multiple-output (MIMO) cellular networks. We consider MIMO cellular networks with G cells, K users/cell with M antennas at each user, and N antennas at each base-station (BS). We assume all channels to KMN KM+N be generic and time varying. We show that DoF/cell can be achieved through one-sided decomposition of a MIMO cellular network (on the user side), followed by the use of an asymptotic interference alignment scheme. We then prove that such an approach { achieves the optimal DoF wheneve