Comparative Study of Scheduling Algorithms in LTE HetNets with Almost Blank Subframe

Abstract

The trend and human lifestyle have been changing, which lead to the tremendously increasing demand for data usage over wireless communication systems even on the go. Traffic offload has been used for LTE Heterogeneous Networks (HetNets) to optimize overall system capacity via load balancing mechanisms among network tiers. In this work, the two main techniques used for interference coordination in the multi-tier systems i.e. Almost Blank Subframe (ABS) and Cell Range Expansion (CRE) have been focused on. Resource scheduling is one of the major issues in LTE HetNets aimed at efficient radio resource allocation. Based on the implementation of ABS and CRE mechanisms, this work investigates the system performance while different scheduling schemes are implemented. Five scheduling schemes including Round Robin (RR), Best-Channel Quality Identification (Best-CQI), Maximum Throughput (Max-TP), Proportional Fairness (PF), and Resource Fairness (RF) are considered here. The simulation studies include a comparison of the LTE HetNet system performance under different ABS and CRE configured parameters as well as employing different scheduling mechanisms. System performance is observed in terms of the average throughput, the peak throughput, the edge throughput, and the fairness index. The results provide recommendations on the system configurations as well as the choice of a scheduler that can be considered or suitable for different scenarios and network planning objectives. Coined from these results, the Best-CQI and the Max-TP mechanism offer the highest peak throughput and the high average throughput. The RR, PF, and RF provide the high cell edge throughput and fairness index, however, the peak throughput has been compromised.