Adaptive multiuser MIMO-OFDM QoS-based scheduler using virtual channel state information

We propose an adaptive multiuser QoS-based scheduler based on the users' channel measurements. In order to mitigate the complexity that results from computing non-codebook based beamformers for possibly infeasible users, we propose to preselect the optimal users using a virtual signal-to-noise ratio (vSNR). This is computed assuming non-interfering users and a total power constraint. Solely depending on vSNR, we obtain thresholds that fulfill the equivalent SINR constraints for a different number of users. In this paper, vSNR thresholds are utilized to develop a fast adaptive multiuser scheduling routine. Finally, a performance comparison to the unscheduled case will be demonstrated in the presence of channel state information uncertainty as well as with perfect channel information.