Spatial stream scheduling in uplink multiuser MIMO systems with zero-forcing post-processing

Abstract

This paper considers an interference-aware user selection and resource allocation for uplink multiuser multiple-input multiple-output (MU-MIMO) systems. At the base station (BS), zero-forcing (ZF) with singular value decomposition (SVD) decoupling of spatial streams is deployed. First, two algorithms are developed for mobile stations (MS)s and their corresponding antennas assignment as well as power allocation. The objective is to maximize the total system sum rate by considering the impact of multiple access noise enhancement on the spatial stream capacity. Then, an additional scheme is proposed to maximize the weighted sum capacity of all admitted users, where the weights are chosen based on the state of users' buffers. The proposed resource allocation and scheduling algorithms operate in a reduced search space for the sub-optimum configurations targeting lower overall complexity but still offering close to optimum results in a statistical sense. Simulation results are provided to demonstrate the potential of the developed technique in terms of total system sum rate performance and the buffer behavior.