Effect of beamforming on full and semi cooperative MIMO in real measured channels

This paper presents an investigation on the behavior of wireless channels in a realistic propagation environment, while cooperation between base stations (BSs) was assumed. Two different scenarios for cooperation were considered in this work. In semi cooperation case, the knowledge of channel state information (CSI) is shared between base stations, but the data is available at each BS locally. In the second state, which is called full cooperation, data and CSI are available at both BSs. The measurements were done by implementing two separate base stations in different locations from users. One base station has 6 and the other one has one antennas. At each measurement time 4 handsets are under test, when each handset has 2 antennas. The measurements were done simultaneously from both BSs to 4 users. Minimum mean square error (MMSE) beamforming criteria was applied as a transmission technique to investigate the effect of beamforming on the capacity of cooperative MIMO system, which shows almost 30% increase in the result.