Optimal pilot reuse in multicell massive MIMO

For a massive MIMO wireless network using uplink pilots to obtain the all-important channel state information (CSI) for beamforming operations, we propose a multi-cell model to analyze the throughput performance with uplink pilot reuses 1, 3, 4 and 7. With conjugate beamforming pre-coding for the downlink and matched filtering de-coding for the uplink, and with power controls that equalizes the user throughout in each cell, in dense urban where cell radius is small and user mobility is moderate, reuse 7 is optimal for user throughput while in suburban where cell radius is large and user mobility is fast, reuse 3 is optimal. In both morphologies, reuse 1 delivers substantially poorer user throughput performance.