非連續接收機制在5G非授權頻譜系統之省電效能分析

DRX Power Saving Performance Analysis over Standalone New Radio Unlicensed Spectrum

胡凱欣(Kai-Hsin Hu)

指導教授 ： 魏宏宇

國立臺灣大學/電機資訊學院/電信工程學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202103703

摘要

第五代無線通訊系統提升了頻寬和傳輸品質，無線通訊網路技術的進步也使行動連網裝置數量急速增加，由於連網裝置的增加，現有的無線網路資源也逐漸無法應付如此龐大的資料量，因此有學者就轉向非授權頻譜的無線網路資源來解決網路擁塞問題。在非授權頻譜中，公平使用一直是很重要的考量，在使用頻譜之前都需要探測頻譜，確認頻譜沒有被佔用後才能使用，然而當頻譜無法使用時，裝置不斷的探測是很耗電的。非連續接收省電機制是不可或缺的省電技術，運營商從第三代無線通訊系統就已經採用非連續省電機制，在該機制下，手機裝置可以進入休眠模式，並且不連續的監聽封包，如此一來手機裝置就可以達到省電的效果。本篇論文中，我們提出一個數學模型來計算非連續省電機制在非授權頻譜下手機省電的效果。我們將第五世代非授權頻譜的頻譜接入程序考量到我們的數學模型來捕捉頻譜接入延遲，我們的模型可以算出省電因子和實際消耗的電量，最後結果顯示在非授權頻譜下使用非連續接收機制可以讓手機省下44到80%的電量。

關鍵字

非連續接收省電機制 ； 第五代非授權頻譜無線通訊系統 ； 毫米波 ； 省電因子 ； 第五代無線通訊系統 ； 第四代非授權頻譜無線通訊系統

並列摘要

5G New Radio (NR) has increased transmission bandwidth and transmission quality. Also, the rapid development in the wireless network drives the growth of the use of mobile devices. However, the traffic growth overpasses the capacity of the NR network. Therefore, researchers have looked beyond 5G and investigate NR unlicensed band (NR-U). Under the unlicensed band, the fairness of using the frequency is a critical issue. It is required to perform channel sensing before operating in the unlicensed bands. Devices are not allowed to transmit data before they access the unlicensed channel successfully. Therefore, the UE keeps consuming its power until the channel is available. Discontinuous Reception (DRX) is one of the most critical energy-saving mechanisms in the 3GPP standard. Operators have already utilized DRX to extend UE's battery life since Universal Mobile Telecommunications System (UMTS). With DRX operation, UE can enter sleep mode and monitor the physical downlink control channel (PDCCH) discontinuously. Consequently, DRX improves the UE's energy efficiency. In this thesis, we propose a NR-U DRX analytical model to calculate the power-saving performance. We incorporate the NR shared spectrum downlink (DL) channel access procedure in our NR-U DRX model to capture the channel access delay. Our model calculates the power saving factor (PSF) and the power consumption. The analytical and simulation results verify our work and reduce 44 to 80 % power consumption comparing NR-U without adopting DRX.

並列關鍵字

DRX ； NR-U ； mmWave ； PSF ； 5G ； LTE-U

參考文獻

[1] 3GPP. NR; Overall description; Stage-2. Technical Specification (TS) 38.300, 3rd Generation Partnership Project (3GPP), 4 2020. Version 16.1.0.

[2] Patrik Cerwall et al. Ericsson mobility report.

[3] Hwan-Joon Kwon, Jeongho Jeon, Abhijeet Bhorkar, Qiaoyang Ye, Hiroki Harada, Yu Jiang, Liu Liu, Satoshi Nagata, Boon Loong Ng, Thomas Novlan, Jinyoung Oh, and Wang Yi. Licensed-assisted access to unlicensed spectrum in lte release 13. IEEE Communications Magazine, 55(2):201–207, 2017.

[4] TSG RAN. Study on NR-based access to unlicensed spectrum. Technical Report (TR) 38.889, 3rd Generation Partnership Project (3GPP), 12 2020. Version 16.0.0.

[5] 3GPP TSG-RAN. New WID proposal for extending NR operation up to 71GHz, 2019.