Relay-aided interference alignment for MIMO cellular networks

Interference alignment scheme for multiple-in multiple-out (MIMO) cellular networks is discussed in this paper. An enhanced relay-aided interference alignment (eRIA) scheme is proposed. To align the interference, the scaling coefficients at relay is designed carefully and the design criterions of eRIA are given. The achievable degrees of freedom (DoF) of eRIA is derived. Both theoretical analysis and simulation results show that compared with Suh´s scheme [8], eRIA can achieve higher DoF and require less time extensions.