User Selection With Effective Channel Quality Feedback for PMI-Based MU-MIMO

This paper addresses user selection for precoding matrix indicator (PMI)-based multi-user multiple-input multiple-output (MU-MIMO) systems. Under a scenario where channel information can only be obtained through PMI, we formulate a problem to find a user set that maximizes the sum-rate of MU-MIMO with maximum ratio transmission precoding. We then analyze that the user set can be determined by solely considering the effective signal power, which is achieved by the convergence of the sum of interference as the numbers of users and antennas go to infinity. Based on the analysis, we propose a user selection algorithm that utilizes the effective signal power. To this end, we introduce feedback of the effective channel quality representing the effective signal power, which is then employed in choosing users. Simulation results demonstrate that our proposed user selection algorithm outperforms existing methods.