Research On Packet Scheduling Algorithm In HSDPA Networks

As a sort of Beyond-3G technologies, High Speed Downlink Packet Access (HSDPA) provides impressive enhancements for the downlink without changing the original network structure. Data services are expected to have tremendous growth in the next few years and will probably become the dominant source of 3G traffic, and moreover, packet scheduling algorithms is an important part of the Radio Resource Management (RRM). And therefore, it will have significant influence on the system performance of HSDPA to carry out the research in the packet scheduling algorithms.Basic theories and key technologies of HSDPA are introduced and analyzed at the beginning of this thesis. RED which is one of the queue management algorithms and packet scheduling algorithms are studied in the following. Then QM-LWDF algorithm which is an improved M-LWDF is proposed in view of defects of traditional queue algorithms and cooperations of queue input and output. QM-LWDF algorithm combines packet loss rate of RED and packet scheduling algorithm of M-LWDF. Delay and queue length are taken into account in packet loss rate. Besides, queue length factor is introduced on the basis of M-LWDF. The simulation results show that QM-LWDF algorithm performs well in system throughput and packet loss rate under limited queue length.