Cross-layer Scheduling and Dynamic Resource Allocation for Downlink Multiuser MIMO Systems with Limited Feedback

In this paper, we present a cross-layer scheduling and dynamic resource allocation (CLSDRA) strategy for downlink multiuser multiple-input multiple-output (MIMO) systems with limited feedback. Based on the instantaneous partial channel state information (CSI) from physical (PHY) layer and the queue state information (QSI) from media access control (MAC) layer, the proposed scheme schedules packets and allocates resources such as channel, bit and power to the scheduled users to maximize the utility function which sums the product of each scheduled user's delay requirement, head of line (HOL) packet waiting time, queue length and data rate. Simulation results demonstrate that our scheme outperforms the existing single-layer resource allocation or scheduling algorithms in balancing the total system throughput and the packet drop rate because the proposed strategy could utilize the QSI and the partial CSI simultaneously.

I. Introduction

With the rapid development of wireless communication techniques and the increasing popularity of wireless broadband services, it is becoming a very challenging task that how to exploit limited radio resources efficiently to obtain high spectral efficiency for future wireless communication systems due to the scarcity of radio resources and the harshness of wireless channel conditions [1]. MIMO wireless system is known of providing considerable capacity without additional spectrum or power [2]. The use of space division multiple access (SDMA) can provide substantial throughput gain in the downlink of multiuser MIMO wireless communications network [3]. Moreover, dynamic resource allocation techniques have attracted enormous research interests and have been identified as one of the most promising techniques, which can achieve both higher system spectral efficiency and better quality of service (QoS) [4].