中国邮电高校学报(英文) ›› 2018, Vol. 25 ›› Issue (3): 1-7.doi: 10.19682/j.cnki.1005-8885.2018.0018

• Wireless •    下一篇

Elevation spatial characteristic investigation based on 3D massive MIMO channel measurements at 6 GHz

郑喆,田磊,张建华   

  1. 北京邮电大学
  • 收稿日期:2018-03-22 修回日期:2018-05-24 出版日期:2018-06-29 发布日期:2018-06-30
  • 通讯作者: 郑喆 E-mail:zhezheng@bupt.edu.cn
  • 基金资助:
    国家自然科学基金优秀青年基金;北京市自然基金;国家科技重大专项;教育部-中国移动科研基金

Elevation Spatial Characteristic Investigation Based on 3D Massive MIMO Channel Measurements at 6 GHz

  • Received:2018-03-22 Revised:2018-05-24 Online:2018-06-29 Published:2018-06-30
  • Contact: Zhe ZHENG E-mail:zhezheng@bupt.edu.cn
  • Supported by:
    National Natural Science Foundation of China; Beijing Municipal Natural Science Foundation;National Science and Technology Major Project of China;The Ministry of Education - China Mobile Research Fund

摘要: As the key technology of fifth generation (5G), 3-dimensional (3D) massive multi-input and multi-output (MIMO) is expected to be widely used in small cell network (SCN). In this paper, in order to investigated the tradeoff between limited size in SCN and the capacity gain from increasing antenna elements,the spatial performances of 3D massive MIMO based on a MIMO channel measurements at 6 GHz in urban microcell (UMi) scenario are studied. Enormous channel impulse responses (CIR) are collected and reconstructed, which enables us to present comparative results of the capacity and the eigenvalue spread (ES). Furthermore, the impacts of antenna element number and spacing on system performance are investigated, i.e., 32, 64, 128 elements are selected from the 512 transmitter (Tx) array with elevation interval spacing being 0.5, 1 and 2 wavelengths for each. Interestingly, the capacity gap can be obviously observed on the comparison between the 1 and 2 wavelength antenna spacing cases, which implies that correlation cannot be ignored when the antenna spacing is larger than 1 wavelength when massive antennas are equipped. The contrast results show that the capacities are enlarged with the increasing of antenna elements number, and larger antenna spacing will lead to higher channel capacity as expected. However, the capacity gains brought by the increasing of antenna spacing will descend to certain degrees as the antenna number increases. Collectively, these results will provide further insights into 3D massive MIMO utilization.

关键词: massive MIMO, channel capacity, eigenvalue spread, elements spacing, antenna number

Abstract: As the key technology of fifth generation (5G), 3-dimensional (3D) massive multi-input and multi-output (MIMO) is expected to be widely used in small cell network (SCN). In this paper, in order to investigated the tradeoff between limited size in SCN and the capacity gain from increasing antenna elements,the spatial performances of 3D massive MIMO based on a MIMO channel measurements at 6 GHz in urban microcell (UMi) scenario are studied. Enormous channel impulse responses (CIR) are collected and reconstructed, which enables us to present comparative results of the capacity and the eigenvalue spread (ES). Furthermore, the impacts of antenna element number and spacing on system performance are investigated, i.e., 32, 64, 128 elements are selected from the 512 transmitter (Tx) array with elevation interval spacing being 0.5, 1 and 2 wavelengths for each. Interestingly, the capacity gap can be obviously observed on the comparison between the 1 and 2 wavelength antenna spacing cases, which implies that correlation cannot be ignored when the antenna spacing is larger than 1 wavelength when massive antennas are equipped. The contrast results show that the capacities are enlarged with the increasing of antenna elements number, and larger antenna spacing will lead to higher channel capacity as expected. However, the capacity gains brought by the increasing of antenna spacing will descend to certain degrees as the antenna number increases. Collectively, these results will provide further insights into 3D massive MIMO utilization.

Key words: massive MIMO, channel capacity, eigenvalue spread, elements spacing, antenna number