University of the Witwatersrand
Opportunistic scheduling exploits multiuser diversity for improving the performance of wireless systems. However, it requires instantaneous Channel State Information (CSI) to be available at the transmitter side. Since acquiring CSI is resource consuming, it always comes at a cost. The authors consider the problem of efficient channel state estimation in the context of 4G mobile broadband systems. Their proposed mechanism selects the subcarriers to be probed per user, by estimating the anticipated tentative rate with and without probing. For the latter an informed guess of the channel state is performed.