Interference Minimization in 5G Heterogeneous Networks

In this paper, we focus on one of the representative 5G network scenarios, namely multi-tier heterogeneous cellular networks. User association is investigated in order to reduce the down-link co-channel interference. Firstly, in order to analyze the multi-tier heterogeneous cellular networks where the base stations in different tiers usually adopt different transmission powers, we propose a Transmission Power Normalization Model (TPNM), which is able to convert a multitier cellular network into a single-tier network, such that all base stations have the same normalized transmission power. Then using TPNM, the signal and interference received at any point in the complex multitier environment can be analyzed by considering the same point in the equivalent single-tier cellular network model, thus significantly simplifying the analysis. On this basis, we propose a new user association scheme in heterogeneous cellular networks, where the base station that leads to the smallest interference to other co-channel mobile stations is chosen from a set of candidate base stations that satisfy the quality-ofservice (QoS) constraint for an intended mobile station. Numerical results show that the proposed user associTao Han · Qiang Li (Corresponding author) · Jing Zhang School of Electronic Information and Communications, Huazhong University of Science and Technology, China E-mail: {hantao, qli_patrick, zhangjing}@hust.edu.cn Guoqiang Mao School of Computing and Communications, University of Technology Sydney, Australia National ICT Australia (NICTA), Australia E-mail: [email protected] Lijun Wang Department of Information Science and Technology, Wenhua College, China E-mail: [email protected] ation scheme is able to significantly reduce the downlink interference compared with existing schemes while maintaining a reasonably good QoS.