A New Allocation Algorithm for Pilot Contamination Mitigation in TDD Massive MIMO Systems

Massive multiple-input multiple-output (MIMO) systems are expected to achieve significant gains in both energy and spectral efficiency compared to conventional MIMO systems. However, these promising gains are limited by the impact of pilot contamination in TDD multicell massive MIMO which results from reusing the same set of pilot sequences in all the system's cells. In this paper, we propose an algorithm for pilot sequences allocation that aims to maximize the minimum achievable rate in a target cell by utilizing the availability of the large-scale fading information at the BSs. Our results show that the proposed algorithm can significantly improve both the spectral efficiency and the minimum achievable rate compared to the conventional pilot allocation scheme which assigns the pilot sequences randomly.