Pilot Assignment Scheme Based on Location in Large-Scale MIMO System

Abstract

As one of the key technology of 5th Generation (5G), large-scale Multiple-Input Multiple-Output (MIMO) system is the development tendency of next generation of wireless communication. A large number of antennas have been used in Base Station (BS) to make the full use of the space dimension which can effectively improve the data transfer rate and spectrum efficiency. However, correlational researches show that the pilot multiplexing causes serious interference among cells which is called pilot contamination. In this paper, we present a novel approach which tackles this problem to reduce the pilot contamination effect in uplink channel estimation. By using of the channel model of steering vector, we analyse Minimum Mean Square Error (MMSE) channel estimation methods. We also obtain the relationship between signal Angle of Arrive (AoA) and channel estimation error. We propose a user selection method based on AoA. The proposed method exploits the location of User Equipment (UE), scatterer, and BS to decrease the channel estimation error. Simulation result shows that it has a significant improvement contrast with the traditional method.