進階搜尋


下載電子全文  
系統識別號 U0026-2708202020213900
論文名稱(中文) 以使用者為中心之Li-Fi網路下的調變等級選擇及功率配置
論文名稱(英文) Joint Modulation Order Selection and Power Allocation for User-Centric Li-Fi Networks
校院名稱 成功大學
系所名稱(中) 資訊工程學系
系所名稱(英) Institute of Computer Science and Information Engineering
學年度 108
學期 2
出版年 109
研究生(中文) 何允中
研究生(英文) Yun-Chung Ho
學號 P76071323
學位類別 碩士
語文別 英文
論文頁數 40頁
口試委員 指導教授-許靜芳
口試委員-廖冠雄
口試委員-張燕光
口試委員-林輝堂
中文關鍵字 Li-Fi  使用者中心之網路  能源效率  區間干擾  不規則細胞  分群  調變等級選擇及功率配置  多重選擇背包問題 
英文關鍵字 Light-Fidelity  User-Centric Networks  Energy Efficiency  Inter-Cell Interference  Clustering  Amorphous Cell  Joint Modulation Order Selection and Power Allocation  Multi-Choice Knapsack Problem 
學科別分類
中文摘要   在Li-Fi微微微蜂巢式網路中,Li-Fi存取點的緊密排列導致嚴重的區間干擾,進而造成效能下降;以使用者為中心之網路其依據使用者位置分佈,動態組成多個不規則細胞,減輕了干擾的狀況。在此篇論文,我們以提升能源效率為目標,分別提出使用者分群演算法,以及調變等級選擇及功率配置演算法。
  在先前的研究中,分群演算法大部分僅考慮把位置較靠近的使用者一一分群,卻未考慮群與群間的距離,因此我們提出新的分群演算法,將使用者依據距離分群之外,並且將建立好的群之間的距離分得儘量遠;在調變等級選擇及功率配置演算法方面,我們採用多重選擇背包問題解決,除此之外,先前的研究大多將干擾項以最差情況進行估算,在超密度的Li-Fi網路下,這樣的估算會造成效能大幅下降,因此我們提出新的不需迭代的干擾項估算方法,將最差情況的上限壓得更低,如此一來可大幅提升效能。在能源效率方面,在我們所提出的使用者分群演算法可達到最多約87.5%的改善幅度。
英文摘要 In traditional Light-Fidelity (Li-Fi) attocell networks, the dense structure of Li-Fi access points (APs) leads to severe inter-cell interference (ICI). User-centric (UC) networks mitigate the inter-cell interference, which dynamically reform amorphous cells as the user mobility varies in time. In this thesis, we propose a new user-centric clustering and joint modulation order selection algorithm respectively with the objective of maximizing energy efficiency (EE).
In previous studies, clustering algorithms usually only aim at minimizing the distance from the centroid of the cluster to each user within the cell. Since inter-cell interference is the main challenge in Li-Fi networks, separating each cells as far as possible is also important. Therefore, in this thesis, we propose a new clustering algorithm that also considers the distance among each constructed cells. On the other hand, we leverage multi-choice knapsack problem for joint modulation order selection and power allocation. Furthermore, different from previous studies, instead of using worst-case estimated interference, a tighter-upper-bounded estimated interference is proposed, yielding better energy efficiency as the power consumption is further reduced. Using our proposed user-centric clustering algorithm, it can achieve up to approximated 87.5 % improvement in terms of energy efficiency.
論文目次 摘要 III
Abstract IV
Contents VII
List of Figures IX
List of Tables XI
Chapter 1 Introduction 1
Chapter 2 Background 2
2.1 Li-Fi 2
2.2 Energy Efficiency 3
2.3 User-centric Networks 3
Chapter 3 Related Work 5
3.1 User-Centric Clustering 5
3.2 UE Formation 5
3.3 AP Formation 6
3.4 AP Switching 6
3.5 Joint Modulation Order Selection and Power Allocation 6
3.6 Interference Estimation 7
Chapter 4 System Model 8
4.1 Lambertian Model 8
4.2 Asymmetrically Clipped Optical Orthogonal Frequency-Division Multiplexing 8
4.3 Transmission Technique 9
4.3.1 Combined Transmission 9
4.3.2 Vectored Transmission 9
4.3.3 Signal-to-Interference-plus-Noise Ratio 10
Chapter 5 Proposed Scheme 11
5.1 Notation 11
5.2 Problem Formulation 12
5.3 Contribution 13
5.4 User-Centric Clustering 13
5.4.1 UE Formation 14
5.4.2 AP Formation 14
5.4.3 AP Switching 15
5.5 Joint Modulation Order Selection and Power Allocation 16
5.5.1 VT-Aided Cells 16
5.5.2 CT-Aided Cells 19
5.5.3 Interference Estimation 20
5.5.4 Conclusion 22
5.6 Complexity Analysis 23
Chapter 6 Performance Evaluation 24
6.1 Parameter Setting 24
6.2 Performance Metrics 26
6.3.1 Comparison between different UE formation methods 26
6.3.2 Comparison among different AP formation methods and different AP switching methods 29
6.3.3 Comparison between different interference estimation 33
6.3.4 Comparison among different dMAX 35
Chapter 7 Conclusion 38
References 39
參考文獻 [1] H. Haas et al., "Introduction to indoor networking concepts and challenges in LiFi," in IEEE/OSA Journal of Optical Communications and Networking, vol. 12, no. 2, pp. A190-A203, February 2020.
[2] Y. Wang, X. Wu and H. Haas, "Resource Allocation in LiFi OFDMA Systems," GLOBECOM 2017 - 2017 IEEE Global Communications Conference, Singapore, 2017, pp. 1-6.
[3] R. Zhang, J. Wang, Z. Wang, Z. Xu, C. Zhao and L. Hanzo, "Visible light communications in heterogeneous networks: Paving the way for user-centric design," in IEEE Wireless Communications, vol. 22, no. 2, pp. 8-16, April 2015.
[4] X. Li, R. Zhang and L. Hanzo, "Optimization of Visible-Light Optical Wireless Systems: Network-Centric Versus User-Centric Designs," in IEEE Communications Surveys & Tutorials, vol. 20, no. 3, pp. 1878-1904, thirdquarter 2018.
[5] S. D. Dissanayake and J. Armstrong, "Comparison of ACO-OFDM, DCO-OFDM and ADO-OFDM in IM/DD Systems," in Journal of Lightwave Technology, vol. 31, no. 7, pp. 1063-1072, April1, 2013.
[6] R. Zhang, H. Claussen, H. Haas and L. Hanzo, "Energy Efficient Visible Light Communications Relying on Amorphous Cells," in IEEE Journal on Selected Areas in Communications, vol. 34, no. 4, pp. 894-906, April 2016.
[7] X. Li, Y. Huo, R. Zhang and L. Hanzo, "User-Centric Visible Light Communications for Energy-Efficient Scalable Video Streaming," in IEEE Transactions on Green Communications and Networking, vol. 1, no. 1, pp. 59-73, March 2017.
[8] M. Obeed, A. M. Salhab, S. A. Zummo and M. Alouini, "New Algorithms for Energy-Efficient VLC Networks With User-Centric Cell Formation," in IEEE Transactions on Green Communications and Networking, vol. 3, no. 1, pp. 108-121, March 2019.
[9] S. Feng, R. Zhang, X. Li, Q. Wang and L. Hanzo, "Dynamic Throughput Maximization for the User-Centric Visible Light Downlink in the Face of Practical Considerations," in IEEE Transactions on Wireless Communications, vol. 17, no. 8, pp. 5001-5015, Aug. 2018.
[10] X. Li, F. Jin, R. Zhang, J. Wang, Z. Xu and L. Hanzo, "Users First: User-Centric Cluster Formation for Interference-Mitigation in Visible-Light Networks," in IEEE Transactions on Wireless Communications, vol. 15, no. 1, pp. 39-53, Jan. 2016.
[11] Lingjiao Chen, Jiaheng Wang, Jiantao Zhou, Derrick Wing Kwan Ng, Robert Schober, and Chunming Zhao, "Distributed user-centric scheduling for visible light communication networks," Opt. Express 24, 15570-15589 (2016).
[12] X. Bao, X. Gu, W. Zhang and H. Chen, "User-Centric Quality-of-Experience Optimization and Scheduling of Multicolor LEDs in VLC Systems," in IEEE Systems Journal, vol. 13, no. 3, pp. 2275-2284, Sept. 2019.
[13] J. Grubor, S. Randel, K.-D. Langer, and J. Walewski, “Broadband information broadcasting using LED-based interior lighting,” J. Lightw. Technol., vol. 26, no. 24, pp. 3883–3892, Dec. 2008.
[14] X. Li, R. Mardling and J. Armstrong, "Channel Capacity of IM/DD Optical Communication Systems and of ACO-OFDM," 2007 IEEE International Conference on Communications, Glasgow, 2007, pp. 2128-2133.
[15] H. Zhang, N. Liu, K. Long, J. Cheng, V. C. M. Leung and L. Hanzo, "Energy Efficient Subchannel and Power Allocation for Software-defined Heterogeneous VLC and RF Networks," in IEEE Journal on Selected Areas in Communications, vol. 36, no. 3, pp. 658-670, March 2018.
[16] Harald Haas, Liang Yin, Yunlu Wang, and Cheng Chen, "What is LiFi?," J. Lightwave Technol. 34, 1533-1544 (2016)
[17] A. Aldalbahi et al., "Extending ns3 to simulate visible light communication at network-level," 2016 23rd International Conference on Telecommunications (ICT), Thessaloniki, 2016.
[18] Patricia Daukantas, "Optical Wireless Communications: The New “Hot Spots”?," Optics & Photonics News 25(3), 34-41 (2014)
[19] Harald Haas, “LiFi is a paradigm-shifting 5G technology”, Reviews in Physics, Volume 3, 2018, Pages 26-31
論文全文使用權限
  • 同意授權校內瀏覽/列印電子全文服務,於2020-08-31起公開。
  • 同意授權校外瀏覽/列印電子全文服務,於2020-08-31起公開。


  • 如您有疑問,請聯絡圖書館
    聯絡電話:(06)2757575#65773
    聯絡E-mail:etds@email.ncku.edu.tw