Experimental investigation of impact of antenna locations on the capacity of wideband distributed antenna systems in indoor environments

Distributed antenna systems (DAS) has been adopted in both indoor and outdoor wireless communications for benefits of reducing the power consumption and enhancing system capacity owing to spatial multiplexing gains. The capacity of a DAS system is partially determined by the cross-correlation of the large-scale fading of multiple links in the system. In this contribution, we use experimental data collected in an indoor environment to investigate the influences of different constellations of the transmit and receive antennas on the channel capacity when the DAS system is deployed within a building. We found that the capacity decreases dramatically when the line-of-sight propagation appears in the constellation. When the spacing of the antennas decreases to 1 meter, the large-scale similarity among the antennas leads to high cross-correlations and as a result, the capacity drops. These observations provide insights for characterization of distributed channels in indoor environments.