Measurement-based performance evaluation of 3D MIMO in high rise scenario

In this paper, the performance of 3D MIMO is evaluated with measurement data for the first time. The MIMO channel response for different 3D antenna configurations is extracted from measured channel matrix in the high rise scenario and the corresponding data rates are calculated. The major findings are as follows. For single user MIMO, vertically spaced antennas does better in transmit beamforming while horizontally spaced antennas stands out in spatial multiplexing for its wider azimuth angle spread. For multi-user MIMO (MU-MIMO), horizontally distributed antennas performs best when users are on the same floor while the combination of closely spaced vertical antennas with widely spaced horizontal antennas is especially more suitable when users are on different floors. Moreover, it is found that for MU-MIMO, the rate increment comes from increase in BS antenna number is limited but increasing the number of users can improve the sum rate effectively. In addition, it is also noticed selecting users on different floors for 3D MU-MIMO can achieve the best performance.