Uplink scheduling for continuous connectivity in high speed packet access systems

The performance efficiency of high speed packet access (HSPA) systems is mainly based on channel quality information (CQI) reports transmitted by user equipment (UE) to Node B. CQI contains the required scheduling information (SI) that is used in the Node B scheduler. However, the frequent CQI reports increase uplink interference, reducing the signal reception quality at the uplink, causing degradation of the system spectral efficiency. In this paper, we propose an improved CQI prediction scheme based on a finite state Markov chain (FSMC) model for wireless channel, in order to reduce CQI signaling overhead in the HSPA system. Then, we introduce an enhanced uplink packet scheduling (EUPS) scheme to provide quality of services (QoS) guaranteed for continuous packet connectivity in the enhanced uplink (EUL). EUPS serves the active UEs not only according to buffer status but also according to reported state of the wireless channel of each UE. The performance of the proposed scheme in terms of average packet delay, average packet drop and average cell throughput is compared to the classical scheduler of 3GPP standards. The simulation results show the effectiveness of the proposed scheme.