The effects of the sub-carrier grouping on multi-carrier channel aware scheduling

Abstract

This paper studies the effects of the sub-carrier grouping on the scheduling problem in a wireless network with multiple carriers. In particular, the authors consider the trade-offs between the size of the sub-carrier groups and the link throughput for various sub-carrier grouping models, with each corresponding to a different level of CSI tracking and system design complexity. The paper assumes that a single user is communicating with the base station using the entire sub-carriers. This assumption is motivated by the OFDM, which uses multiple carriers in order to benefit from the frequency selective fading introduced by spreading the information bits over the entire signal band. An offline dynamic programming algorithm for finding an optimal solution for the case of spectrum- and time-perfect estimates is also presented. The performance can potentially be improved by using high-level modulation on the sub-carriers with good channel conditions.