A signal-to-interference ratio based downlink scheduling scheme for WCDMA mobile communication system

In this paper, we propose a QoS-aware power-strength classified packet scheduling (PCPS) scheme that can classify the transmission power-strength of a VBR connection into several classes and determine the admitted service rate of each class at connection setup time. During the transmission time of each connection, PCPS scheme can dynamically adjust the downlink service rate of each connection in accordance with the admitted service rate of the current transmission power-strength class while retaining all connection's Frame Error Rate requirements. With this power-strength classified scheduling, PCPS scheme can decrease the average packet delay and increase the bandwidth utilization. Furthermore, a two-stage scheduling architecture is also employed to reduce the scheduling complexity resulted from simultaneous adjustment of both service rate and transmission power-strength in WCDMA. Performance results show that the delay bound and the packet loss ratio of a VBR connection can be guaranteed.