A POWER EFFICIENT PILOT DESIGN FOR MULTI-CELL MASSIVE MIMO SYSTEMS

In this paper, we address the pilot contamination problem in multi-cell Massive MIMO systems. Particularly, we propose a pilot design scheme that simultaneously minimizes the channel estimation errors of all base stations (BSs) and the total pilot power consumption of all users subject to the transmit power constraint for every user in the network. We decompose the proposed non-convex problem into distributed optimization problems to be solved at each BS, assuming the knowledge of pilot signals of the other BSs. Then, we introduce a successive optimization approach to cast each distributed optimization problem into a convex linear matrix inequality form. Simulation results confirm that the proposed approach significantly reduces pilot power while maintaining the same level of channel estimation error as a recent work in [1].