Simulation of Multiple-Antenna Terminal Performance in Massive MIMO Systems Based on Indoor Measurements

Abstract

In massive MIMO systems the uplink pilot signals transmitted by a terminal define the channel seen by the base station. This gives the terminal some degree of freedom selecting an uplink pilot transmission strategy. In this paper, we investigate the benefit of different pilot transmission strategies when increasing the number of antennas in the terminal. Building on previous work on a simulation framework for Multiple-antenna terminals in 5G massive MIMO systems, this paper presents simulated performance results for various transmission schemes. The results are calibrated to reflect a real communication situation in a large auditorium. Emulating the measurement set-up, we show that the framework can be tuned to generate channel distributions that match measured data. Under generalized conditions, we perform simulations for different terminal transmission-strategies, both related to single stream and multiple streams. All evaluations are based on terminals with four antennas integrated into real Sony Xperia smartphone-chassis, tuned to 3.7 GHz. The measurements are conducted by using the Lund University Massive MIMO testbed with its 100 antennas. The results clearly show the advantage of increasing the antenna-count also at the terminal side in massive MIMO systems.