Capacity of the mobile MIMO channel for a small wireless handset and user influence

We obtained results on the capacity of a mobile MIMO channel and on the influence of the user. Measurements were done in a configuration with three distributed transmitters equipped with single antennas and with a small wireless handset with four antennas, creating a 4Rx x 3Tx configuration. We express the quality of the radio channel in terms of the Effective Degree of Freedom (EDOF)[1]. From our measurement it follows that fitting a small handset with multiple antennas still makes sense in an outdoor-to-indoor mobile MIMO scenario. The channel capacity can be excellent, comparable with fully uncorrelated Rayleigh fading branch signals. However, on average the user should be satisfied with less favourable conditions amounting to a loss in EDOF of 0.16 at 50% Complementary Cumulative Distribution Function (CCDF) level. Systems operating without power control will suffer from an extra degradation in EDOF of 0.10 with an increased spread in channel quality both at the high and low end of the EDOF curve.