Proactive CCI evaluation and transmission gain based scheduling for MU-MIMO broadcast channel

In this paper a scheduling algorithm based on proactive co-channel interference (CCI) evaluation for multiuser multiple-input multiple-output (MU-MIMO) broadcast channel (BC) is proposed. The strategy converts user scheduling to spatial subchannel selection problem. A new parameter η, named as proactive CCI evaluation factor is defined for estimating the existing and potential mutual interference. With different settings of η, the proposed algorithm can be generalized to some existing reactive scheduling methods. The user and subchannel scheduling criterion as well as processing procedure are presented in this paper. By appropriately choosing η and comprehensively considering candidate subchannel transmission gain, along with mutual interference among candidate and activated subchannels as well as those would be selected subsequently. A set of sub-channels with less CCI are scheduled, and an improvement of system sum rate is achieved. Simulation results show that compared with those reactive methods, given appropriate η the proposed algorithm could achieve better tradeoff between system sum rate improvement and computational complexity control.