Research On Scheduling Schemes In LTE System

Abstract: In response to the rapid growth of mobile data access requirements,3GPP proposedlong-term evolution (LTE) standards at the end of2004. LTE has incorporated a variety of newtechnologies, such as OFDM and MIMO. The use of these technologies has improved theperformance of the system, however it also increased the complexity of the LTE wireless resourcemanagement. As the core of the wireless resource management, resource scheduling has become thekey to the rational use of limited bandwidth resource, improvement of the system performance andthe user experience.this paper focus on the resource scheduling schemes. first of all, the architecture and wirelessresource management of LTE system were introduced. then, the classical scheduling schemes andresearch situation of LTE system were analyzed. Finally, two efficient resource scheduling schemeswere proposed for downlink and uplink respectively.To the downlink, the IFLS scheme which is for hybrid multimedia service was proposed. TheIFLS scheme consists of two component：The upper scheduler and the lower scheduler. The upperscheduler calculates the amount of data that need to be transferred for the real-time service at thebegin of each LTE frame. The lower scheduling unit control the scheduling priority of real-time andnon real-time servic through the scheduling Metric. The scheduling priority of real-time service willbe raised rapidly at the end of one LTE frame in order to guarantee Qos requirement of real-timeservices. simulation results show that IFLS scheme improves the throughput of non real-timeservice, and the system got further improvement in spectrum efficiency.To the uplink, a best cut point (BCP) scheduling scheme based on proportional fair scheme wasproposed. In order to get the maximum throughput，the scheme distribute the RB with the bestMetric to each ue, then search for the best cut point of resources section for each ue. The simulationresults show that BCP scheme can obtain fairly good UE fairness and system throughput, and tosome extent, cope with instantaneous large scale decline in frequency domain.