Analysis and Optimization of Inter-Tier Interference Coordination in Downlink Multi-Antenna HetNets with Offloading

Yueping Wu, Ying Cui, Bruno Clerckx

Research output: Contribution to journalArticlepeer-review

23 Citations (Scopus)


Heterogeneous networks (HetNets) with offloading is considered as an effective way to meet the high data rate demand of future wireless service. However, offloaded users suffer from strong inter-tier interference, which reduces the benefits of offloading and is one of the main limiting factors of system performance. In this paper, we investigate an interference nulling (IN) scheme in improving system performance by carefully managing the inter-tier interference to the offloaded users in downlink two-tier HetNets with multi-antenna base stations. Utilizing tools from stochastic geometry, we first derive a tractable expression for the rate coverage probability of the IN scheme. Then, by studying its order, we obtain the optimal design parameter, i.e., the degree of freedom that can be used for IN, to maximize the rate coverage probability. Finally, we analyze the rate coverage probabilities of the simple offloading scheme without interference management and the multi-antenna version of the almost blank subframes (ABS) scheme in 3GPP LTE, and compare the performance of the IN scheme with these two schemes. Both analytical and numerical results show that the IN scheme can achieve good performance gains over both of these two schemes, especially in the large antenna regime.

Original languageEnglish
Article number7156167
Pages (from-to)6550-6564
Number of pages15
JournalIEEE Transactions on Wireless Communications
Issue number12
Publication statusPublished - 2015 Dec


  • Heterogeneous networks
  • inter-tier interference coordination
  • multiple antennas
  • offloading
  • optimization
  • rate coverage probability
  • stochastic geometry

ASJC Scopus subject areas

  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Applied Mathematics


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