Long-Term CSI Based Multi-User Scheduling for Collaborative Spatial Multiplexing in Mobile-WiMAX

Abstract

In this paper, we propose a multi-user scheduling scheme to maximize the ergodic sum-rate of the uplink of a multi-user multiple-input multiple-output wireless system. The proposed scheduling scheme only utilizes the receive correlation information of users without instantaneous channel state information (CSI). It can be applied to the collaborative spatial multiplexing mode specified in the IEEE 802.16e mobile-WiMAX system, where the number of users in transmission is limited to the number of receive antennas of the BS at each time slot. An upper-bound analysis and numerical results show that the proposed scheduling scheme outperforms conventional random scheduling scheme in terms of the ergodic sum-rate without loss of opportunity fairness. Moreover, the proposed scheduling scheme can provide an ergodic sum-rate comparable to full-CSI based scheduling scheme in the presence of user mobility, while significantly reducing the feedback signaling overhead.