A Novel Pilot Allocation Scheme for TDD Massive MIMO Systems

Pilot contamination affects the system performance of time division duplex (TDD) massive multiple-input multiple-output (MIMO) systems, and many pilot allocation methods are proposed to reduce pilot contamination. However, most existing pilot allocation methods focus on the scenes that cells are regular shape or the number of users in each cell is equal, so these methods can not be used in the actual scenes with irregular shaped cells and randomly distributed users. In order to solve this problem, the idea of coalition game is introduced into the pilot allocation method in this paper, and a novel pilot allocation scheme based on coalition game, which can be used in any actual scene, is proposed. Simulation results show that the proposed scheme can effectively reduce pilot contamination and improve average spectrum efficiency of the uplink.