Dynamic Pilot Assignment in Massive MIMO Systems with Time-Shifted Pilot

摘要

The time-shifted pilot with downlink data overlap considering an infinite number of antennas in base station can mitigate pilot contamination well, but there is still interference between the cells in the same group. Different from the conventional random pilot assignment method, this paper proposes a dynamic pilot assignment method based on the interference degree of cells in the same group of the system. For the system with severe inter-cell interference, we use the pilot assignment method which maximizes the center cell's minimum uplink SIR considering the total interference to the user to mitigate pilot contamination. For the system with slight inter-cell interference, we use the pilot assignment method which maximizes the center cell's average uplink SIR considering the total interference to the user to improve its performance. The effectiveness of the pilot assignment method proposed in this paper is verified by simulation experiments.