User scheduling for capacity-Jain's fairness tradeoff in millimeter-wave MIMO systems.

Highlights • Approximately achieve tradeoff between capacity and Jain's fairness that cannot increase fairness while not decrease capacity. • Analog beamforming and user grouping are designed to suppress interference. • Complexity is comparable to most of the existing scheduling approaches. Abstract This paper investigates user scheduling in millimeter-wave multiple-input multiple-output systems that can achieve a tradeoff between capacity and Jain's fairness index. By decomposing the original problem into digital beamforming design, duration allocation, and analog beamforming design, each subproblem is solvable. It is proved that the duration allocation problem possesses a property such that the convex optimization algorithm can be employed for the near optimal result. Moreover, the analog beamforming vectors and the user grouping are designed to avoid interference caused by the reuse of the same subspace. Finally, the computational complexity of the proposed approach is analyzed and is compared with that of other approaches. The simulations verify that the proposed approach can achieve the highest fairness and a higher capacity than approaches of close fairness. [ABSTRACT FROM AUTHOR]