Research on Optimality of Centralized Scheduling and Distributed Rate Control

Abstract

On the reverse link of CDMA systems, two options are possible for resource allocation: rate control (RC) and centralized scheduling (CS). The rate control algorithm can be further divided into Common Rate Control (CRC) and Dedicated Rate Control (DRC). In CRC, each mobile station (MS) independently determines its reverse link rate using the system interference level information broadcasted by a base station (BSs) and rate control mechanism at the MS side. While in DRC, the BS sends each MS a rate movement command. On the other hand, centralized scheduling directly assigns reverse link rates to a subset of MSs. In this paper, the Token Bucket based Common Rate Control (TB- CRC) mechanism is discussed and compared with the centralize scheduling. Performances have been evaluated through system level simulation. It is shown that the token bucket based rate control philosophy outperforms the centralized scheduling from the aspect of throughput, fairness, system stability, signaling overhead and transmission delay.