Multiplexing efficiency of MIMO antennas with user effects

Recently, the multiplexing efficiency metric is proposed for characterizing the MIMO performance of terminal antennas. Here, we show that it can also provide useful insights into the impact of user on MIMO terminal performance. In particular, the impact of user hand and head on the efficiency and correlation of a MIMO antenna can be conveniently quantified using the multiplexing efficiency metric. For example, we find that the hand introduces a 4 dB loss in total efficiency relative to the free space case, for a penta-band two-element MIMO terminal antenna operating at 750MHz. However, the multiplexing efficiency drops by only 2.4 dB, due to the de-correlation effect of the hand partly compensating the loss in total efficiency.