Beamforming Signal Processing Performance Analysis for Massive MIMO Systems

Abstract

ITU-R requirements related to technical performance for IMT-2020 radio interfaces claims average spectral efficiency (SE) up to 9 bit/s/Hz for indoor hotspot, 7.8 bit/s/Hz for dense urban and 3.3 bit/s/Hz for rural environment. The purpose of this work is to analyse the performance of beamforming signal processing techniques for various massive MIMO configurations in terms of SE and reveal scenarios, which meet ITU-R requirements. Analysis is performed for single user (SU) and multi-user (MU) cases with 14, 50, 100 users, various number of antenna ports (8, 32, 64 and 128) and three beamforming techniques: matched filter (MF), minimum mean square error (MMSE) and zero-forcing (ZF). Simulation results compare SE as a function of signal-to-noise ratio (SNR) for various beamforming techniques and conclude that at higher SNR MMSE acts as ZF and at low SNR MMSE acts as MF for the case, when the number of users is much lower than the number of antenna ports. MU case analysis reveal, that ITU-R average SE requirements hold only in rural environment for high SNR values and 128 antenna ports.