A Time-of-Stay Estimation-Based Handover Algorithm for LTE Heterogeneous systems

• Main Authors: Kai-ChengLin, 林楷晟
• Other Authors: Szu-Lin Su
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/v9bze4

碩士 === 國立成功大學 === 電腦與通信工程研究所 === 105 === In recent years, to satisfy the rapidly increased users’ demand of mobile data communications, heterogeneous network (HetNet), which is composed of macrocells and small cells (picocells, femtocells), has been widely discussed in LTE systems. HetNet system is capable of reducing transmission energy, improving spectrum efficiency, and increasing data throughput. However, as the increase of small cell density, users’ unnecessary handovers and ping-pong effects among cells cause higher complexity and lower quality of service. To avoid users’ improper handovers, most of the conventional handover algorithms adopted directly the user’s speed as the handover decision criterion. In practice, these schemes cannot reduce ping-pong effects and, moreover, will miss the opportunity to re-allocate macrocells’ loading. Hence, this project adopts not only the fuzzy Q-learning algorithm to achieve load balancing among cells, but also a link prediction algorithm (LPA) to estimate user’s time-of-stay (ToS) in target cell which is used as one of handover decision criteria. Simulation results show that the proposed handover algorithm based on ToS estimation can effectively reduce ping-pong effects and will not result in severe call drop rate (CDR).