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Content placement in cache-enabled sub-6 GHz and millimeter-wave multi-antenna dense small cell networks
journal contribution
posted on 2018-07-09, 09:37 authored by Yongxu Zhu, Gan Zheng, Lifeng Wang, Kai-Kit Wong, Liqiang Zhao© 2018 IEEE. This paper studies the performance of cache-enabled dense small cell networks consisting of multi-antenna sub-6 GHz and millimeter-wave (mm-wave) base stations. Different from the existing works which only consider a single antenna at each base station, the optimal content placement is unknown when the base stations have multiple antennas. We first derive the successful content delivery probability by accounting for the key channel features at sub-6 GHz and mm-wave frequencies. The maximization of the successful content delivery probability is a challenging problem. To tackle it, we first propose a constrained cross-entropy algorithm which achieves the near-optimal solution with moderate complexity. We then develop another simple yet effective heuristic probabilistic content placement scheme, termed two-stair algorithm, which strikes a balance between caching the most popular contents and achieving content diversity. Numerical results demonstrate the superior performance of the constrained cross-entropy method and that the two-stair algorithm yields significantly better performance than only caching the most popular contents. The comparisons between the sub-6 GHz and mm-wave systems reveal an interesting tradeoff between caching capacity and density for the mm-wave system to achieve similar performance as the sub-6 GHz system.
Funding
This work was supported by the U.K. Engineering and Physical Sciences Research Council under Grant EP/N007840/1 and Grant EP/N008219/1 and in part by the National Natural Science Foundation of China under Grant 61771358.
History
School
- Mechanical, Electrical and Manufacturing Engineering
Published in
IEEE Transactions on Wireless CommunicationsVolume
17Issue
5Pages
2843 - 2856Citation
ZHU, Y. ... et al., 2018. Content placement in cache-enabled sub-6 GHz and millimeter-wave multi-antenna dense small cell networks. IEEE Transactions on Wireless Communications, 17(5), pp. 2843-2856.Publisher
IEEEVersion
- VoR (Version of Record)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution 3.0 Unported (CC BY 3.0) licence. Full details of this licence are available at: http://creativecommons.org/licenses/by/3.0/Publication date
2018-02-09Notes
This is an Open Access Article. It is published by IEEE under the Creative Commons Attribution 3.0 Unported Licence (CC BY). Full details of this licence are available at: http://creativecommons.org/licenses/by/3.0/ISSN
1536-1276Publisher version
Language
- en