HARQ aware scheduler in downlink packet data systems

06 October 2003

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Third generation wireless systems typically employ link adaptation, scheduling, and hybrid automatic repeat request (HARQ) techniques to provide high speed packet data service on the downlink. While prior scheduling algorithms based on the instantaneous data rate to determine the user to be served in each scheduling interval are useful, they do not fully take into account transmission errors and the resulting performance impact of retransmission techniques to recover those errors. We propose a more accurate measure of users' data rates (i.e., their effective data throughput rates) that accounts for the frame error rate (FER) as well as retransmissions when scheduling transmissions to users. Extensive simulation results comparing performance of the proposed methods to conventional methods are presented.