Field experimental evaluation of higher rank MIMO in quad-directional UE antenna configuration for 5G radio access system

This paper presents field experiments on the downlink performance of a 5G radio access system employing higher rank MIMO in the quad-directional antenna configuration at UE side comparing the uni-directional antenna configuration in typical small cell environments. Each antenna branch of the quad-directional antenna directs for intervals of 90 degrees in horizontal plane. The results show Rank-8 transmission performance is better compare to the uni-directional antenna configuration even the antenna gain is degraded, because the spatial correlation of UE becomes low using the quad-directional antenna in the environment has many complex reflection paths. And also it shows the stable performance of throughput about the dependency of the UE antenna direction. The antenna covers omni direction with combining all antenna branches and the spatial correlation is low compare to the uni-directional antenna. The performance is tradeoff of degradation of the total antenna gain.