Adaptive Adjustment of TDD Uplink-downlink Configuration based on Cluster Classification in Beyond LTE Heterogeneous Networks

• Main Authors: Yu-Jie Wang, 王郁傑
• Other Authors: Wen-Shyang Hwang
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/6xkm5h

碩士 === 國立高雄應用科技大學 === 電機工程系博碩士班 === 103 === Heterogeneous networks (HetNets) are constituted by different types of base stations (eNBs), its architecture is to deploy many small cells with low transmission power at the hotspot space or cell edge in the range of large base station (Macro eNB) with high transmission power. Therefore, the objective of Beyond LTE does dispose more Pico eNBs to meet the traffic demand of user equipment (UE). The LTE Time Division Duplexing (TDD) system had been defined 7 uplink-downlink sub-frame configurations. For instance, two neighboring eNBs of TDD system using different uplink-downlink configuration; there are some sub-frames sent from one eNB in the uplink transmission, while some sub-frames are from another eNB in the downlink transmission. It will make UE be subjected to the interference by this different direction transmission, and result in overall network performance degradation. It is called the DL-UL cross interference. In this paper, we propose a cluster classifications mechanism to divide Pico eNBs into different groups according to the interference degree of each Pico eNB. If the interference is low that implied UE may receive a good quality signal from eNB now, so the Pico eNB could use the adaptive adjustment TDD uplink and downlink configuration to increase system transmission capacity. However, the interference is high that indicated UE may receive poor signals because of the affected interference from other neighboring eNBs, hence the Pico eNB may enable the interference mitigation methods to reduce the DL-UL cross interference. By this proposed mechanism, Pico eNBs will be divided to different groups for choosing their suitable mechanism, and to improve the network throughput and increase the spectrum utilization.