Multi-Panel Based Hybrid Beamforming for Multi-User Massive MIMO

Targeting massive Multiple Input Multiple Output (MIMO) systems, we consider an efficient multi- panel array architecture and propose hybrid beamforming techniques for millimeter wave frequencies. Taking advantages of the multi-panel array, hybrid two-stage processing including coarse and fine beamforming can be carried out in a distributed fashion. Panel-coordinated analog beamforming as well as decoupling only requires channels measured at each panel itself. Non- linear precoding is then applied on a per-panel basis. It is shown that the proposed schemes relax the antenna dimensionality constraint and exhibit a good performance even in an overloaded case, which are practically feasible in both the single-/multi-cell scenarios.