On the Characterization of MU-MIMO Channels

In this paper, the authors study the divergence of different links in wide-band Multi-User Multiple-Input Multiple-Output (MUMIMO) channels. The divergence is measured on several levels: spatial separation of the user's correlation matrices, co-linearity of the MIMO channel matrices, and correlation of large scale fading. The measurement data has been acquired using Eurecom's MIMO Openair Sounder (EMOS). The EMOS can perform real-time MIMO channel measurements synchronously over multiple users. For this paper, they have used an outdoor measurement with two transmit antennas and two users with two antennas each.