Enhanced broadband wireless networking through macroscopic diversity combining applications of MIMO technology

Multiple-input multiple-output (MIMO) systems can enable drastic increments in channel capacity by employing array antennas both at the transmitter and the receiver. However, the capacity of MIMO systems degrades severely when spatial correlation among multipart channels is present. In this paper, we show that the channel capacity is dominantly affected by shadowing, rather than multipath correlation. To overcome this adverse shadowing effect, we consider macroscopic selection diversity (MSD) scheme on top of MIMO technology, and provide an analysis of capacity outage probability for MSD-MIMO systems. The numerical results show that significant improvement is observed even with 2 base station (BS) diversity. It is also observed that the effect of spatial correlation due to multipath fading is almost negligible when multiple BSs cooperatively participate in the mobile communication scheme. Combined with the BS selection scheme, the proposed MSD-MIMO system overcomes adverse shadowing phenomena while obtaining spatial multiplexing gain in MIMO channels.