Pilot allocation based on users’ location and user classification in massive MIMO system

Abstract

Aiming at the problem of pilot contamination in massive MIMO systems,a pilot allocation scheme based on users’ location and user classification was proposed.The scheme designed the objective function and reasonable threshold based on path loss and angle of arrival.By comparing the user’s objective function with the threshold,all users in the system were divided into two types:high interference and low interference,and the low-interference users multiplex pilot sequences and extra orthogonal pilot sequences were assigned to high interference users to mitigate pilot contamination.Simulation results show that the scheme improves the performance of the communication system.

Keywords

• massive MIMO;pilot contamination;pilot allocation;NMSE;signal to noise ratio;achievable sum rate