An AoA-aided Low Complexity Pilot Decontamination Scheme for Multi-Cell Massive MIMO Systems

This paper investigates the pilot contamination issue in a multi-cell massive MIMO system. To this end, utilizing both the angular information and the distance information, a framework is presented to formulate a pilot contamination-aware pilot assignment. In the following, a pilot assignment strategy is proposed, where compared to the conventional algorithms, an alternative optimization problem with low complexity is extracted. To do so, the pilot assignment problem is reformulated by another problem whose variables are continuous. After that, the resultant optimization is treated via an iterative method, where the sequential convex programming (SCP) is employed. The simulation results show that the proposed algorithm can achieve a performance that is comparable to the conventional method with a complexity decrease, at the cost of a negligible reduction in the uplink sum rate per cell.