Downlink packet-scheduling considering transmission power and QoS in CDMA packet cellular systems

It is expected that as the integration proceeds between mobile communication systems and the Internet, the amount of data traffic will drastically increase in the IMT-2000 (3G) and beyond (4G) mobile communications systems. With the demand for high-speed mobile multimedia and that for supporting diverse user requirements, wireless QoS (quality of service) will play an important role and becomes a challenging issue, due to the dynamic fluctuating nature in wireless channel conditions and the limited availability of radio resources. Especially in the CDMA cellular system where radio resource is shared among cells, the dynamic fluctuating nature in the wireless channel may more-profoundly affect the user QoS. From these perspectives, this paper focuses on packet-scheduling aimed at utilizing radio resources efficiently while supporting user's QoS. Novel packet-scheduling schemes proposed here, STPD and STPD-SPF, cannot only utilize radio resource efficiently by considering required transmission power, but also support QoS of each user by monitoring buffering delay. Simulation results indicate that these schemes can improve traffic performance and QoS satisfaction rate.