Interference Coordination for Heterogeneous Users in Asynchronous Fog Radio Access Networks

In this letter, we propose a novel multi-input multi-output (MIMO) interference coordination (IC) technique for uplink fog radio access networks (F-RANs), consisting of two multi-antenna remote radio heads (RRHs) connected to a single fog access point (F-AP) and user equipments (UEs) equipped with different numbers of antennas. It is assumed that UEs are scheduled with an asynchronous manner for each RRH. With the proposed MIMO IC technique, the interference dimension at each RRH is dynamically adjusted via transmit beamforming at the selected UEs based on both currently scheduled UEs and their antenna configurations. To the best of our knowledge, the MIMO IC exploiting heterogeneous multi-antennas at UEs is first proposed in this letter for the F-RANs. Numerical results show that the proposed technique outperforms the conventional schemes in terms of sum rates.