Utility Based Scheduling Algorithm for Multiple Services Per User in MIMO OFDM System

This paper focuses on adaptive resource scheduling for multiple services per user at the downlink of multiple input multiple output (MIMO) - orthogonal frequency division multiplexing (OFDM) system. In future wireless networks, one user will simultaneously require multiple homogeneous or heterogeneous services. Then, the scheduling algorithm is responsible for not only assigning resource blocks to different users but also distributing the assigned resource blocks among multiple services for one user. This paper firstly formulates this integrated optimization problem based on utility function in homogeneous service system. As the solution to the optimization problem requires high computational complexity, a sub-optimal and low-complexity algorithm is proposed with two theorems for practical implementation. Moreover, the algorithm is extended to heterogeneous services system by classifying delay sensitive services according to the head-of-line packets delay. The design goal of the algorithm is to fully exploit multiuser diversity gain while guaranteeing the quality of service (QoS) for delay sensitive services. Numeric results show that the algorithm outperforms traditional algorithm in terms of system spectral efficiency and fairness criterion.