Measurement-based Misalignment Analysis of Dual-polarized 2 × 2 LoS MIMO System at 28 GHz

The Line-of-sight (LoS) multiple input multiple output (MIMO) system is a promising solution to increase the data rate for directional communication links. In order to achieve the optimum spectrum efficiency of a LoS MIMO system, the spatial distribution of antennas is the dominant factor. Hence, it is crucial to comprehend the spectrum efficiency degradation result from the imperfect antenna placements. In this paper, misalignment including changes of antenna spacing, link distance and rotations are taken into consideration in a 2 × 2 dual polarized LoS MIMO system at 28 GHz. Measurement results show favorable agreements comparing with simulation results. Overall, we draw the conclusion that these misalignment effects need to be noticed and carefully adjusted in a LoS MIMO system in order to maximize the system performance.