K-Means Mu-Mimo User Clustering For Optimized Precoding Performance

Multi-User (MU) Multiple-Input-Multiple-Output (MIMO) systems have been extensively investigated over the last few years from both theoretical and practical perspectives. Linear Precoding (LP) schemes for MU-MIMO are already used in Long Term Evolution (LTE) for their low complexity, however, they do not work well for users with strongly correlated channels. Finding the optimum set of co-scheduled users, provided their channels are separated enough, could require an exhaustive search, and thus may not be affordable for practical systems. The purpose of this paper is to present a new semi-orthogonal users selection algorithm based on the statistical K-means clustering and to assess its performance in MU-MIMO systems.