Impact of User Mobility and Asymmetry on Multiuser Scheduler Performance

In this paper, we are concerned with the performance of multiuser schedulers over an asymmetric network, where different users in the network have different average received signal-to-noise ratios (SNRs) and Doppler spreads. The throughput, in terms of the ergodic capacity of the channel, of a maximum-SNR scheduler (i.e., the scheduler that schedules the user with the largest instantaneous SNR) is investigated over Rayleigh fading channels with single- antenna base station and user terminals. Closed-form expressions are presented to quantify the degradation in maximum- SNR scheduler performance due to lack of the knowledge of the CSI. For an asymmetric network with a small number of users, a new simple scheduler, which does not require instantaneous CSI, is proposed, and its optimality is discussed.