Performance of Scheduling Algorithms for HSDPA

The high speed downlink packet access (HSDPA) is one of the newest extensions to the Universal Mobile Telecommunications System (UMTS). HSDPA allows for higher data rates due to new adaptive modulation and coding (AMC) techniques, a hybrid automatic repeat request (H-ARQ) protocol and a fast scheduling algorithm. The fast scheduling, taking into account the current channel conditions of each user, contributes significantly to the performance of HSDPA by the so called multiuser diversity gain. Within the scope of this paper several scheduling algorithms are introduced and are analyzed with respect to both, the overall system performance and the individual user quality of service (QoS) constraints. Results illustrate the trade-off between the conflicting targets of high cell throughput and the delay requirements for real-time services.