碩士 / 國立成功大學 / 電腦與通信工程研究所 / 106 / In recent year, beam tracking plays a big role in 5G mmWave wireless communications. Because of severe power attenuation of mmWave transmission, the exploitation of antenna gain provided by a large antenna array and directional transmission through beamforming have been extensively considered to enhance the transmission rate of coverage of mmWave. For mmWave communication based on beamforming, tracking the direction of individual user equipment(UE) is of vital importance to maximize the directional transmission gain. Numerous beam tracking schemes have been developed. Some of them track UEs by prediction. According to historical tracking results, the UE’s spatial direction can be tracked following a known movement pattern. However, prediction-based tracking is sensitive to the error due to the inaccurate knowledge of the initial location. In addition, the movement pattern is seldom fixed and thus the prediction-based tracking can hardly implemented in practice. More importantly, all the existing tracking schemes either consider a single UE only or need to track multiple UEs one by one. We propose a beam tracking scheme that can track multiple UEs more efficiently. The proposed scheme keeps tracking the strongest beam for each UE by leveraging the spatial resolution inherent in the beamspace MIMO channel. Consequently, the strongest beam can be tracked without resorting to channel estimation and does not require any knowledge on the movement pattern. To track multiple UEs simultaneously, UEs are partitioned into groups and each group is assigned with an orthogonal pilot sequence. By allowing UEs of different groups to send pilot sequences using the same time resource, the base station (BS) is able to track them simultaneously. Simulation is performed to study the performance of the proposed beam tracking scheme in comparison with existing methods under the mobile scenario.
| Identifer | oai:union.ndltd.org:TW/106NCKU5652035 |
| Date | January 2018 |
| Creators | Peng-YuLai, 賴鵬宇 |
| Contributors | Kuang-Hao Liu, 劉光浩 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | en_US |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 45 |
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