  The two-stage precoding has been proposed to reduce the overhead of both the
channel training and the channel state information (CSI) feedback for the
massive multiple-input multiple-output (MIMO) system. But the overlap of the
angle-spreading-ranges (ASR) for different user clusters may seriously degrade
the performance of the two-stage precoding. In this letter, we propose one ASR
overlap mitigating scheme through the base station (BS) selection. Firstly, the
BS selection is formulated as a sum signal-to-interference-plus-noise ratio
(SINR) maximization problem. Then, the problem is solved by a low-complex
algorithm through maximizing signal-to-leakage-plus-noise ratio (SLNR). In
addition, we propose one low-overhead algorithm with the lower bound on the
average SLNR as the objective function. Finally, we demonstrate the efficacy of
the proposed schemes through the numerical simulations.
