為了因應行動通訊網路快速成長及可用頻譜不敷使用之問題，頻譜相對充裕的毫米波(Millimeter Wave, MMW)成了5G行動通訊不可或缺的一環。由於毫米波的物理特性導致傳輸距離不遠，所以因應毫米波未來5G需大量佈建小型基地台(Small Cell)。
在集中式光纖無線整合前傳網路的架構下，密集佈建小型基地台在下行(Downlink)多點協作(Coordinated Multi-Point, CoMP)之場景會遇到一些問題，因每個基地台涵蓋範圍變小，導致與涵蓋範圍內用戶有關的基地台都要提供用戶服務，且每個基地台都需空出一個通道(Channel)，如此一來便會降低頻譜效益(Spectral Efficiency, SE)，尤其當邊緣使用者用戶增加時，頻譜效益就急速下降。
本論文為了提高頻譜效益、改善邊緣使用者用戶接收品質以及考量大量佈建小型基地台硬體成本，在集中式光纖無線整合前傳網路的架構下提出非正交多重接取(Non-Orthogonal Multiple Access, NOMA)技術結合CoMP之概念，並經由實驗展示在5G毫米波光纖無線整合前傳系統(Fiber Wireless Integration Fronthaul System)中。傳送端透過基頻處理單元(Baseband Unit, BBU)聯合處理(Joint Processing, JP)，將各個遠端無線電頭(Remote Radio Head, RRH)要傳輸的訊號資料，統一在基頻處理單元產生，這樣一來可以節省整個系統的成本，以利於未來5G密集佈建小型基地台，同時可以確保訊號的同步性。接著透過光纖(Optical Fiber)將訊號傳遞到各個遠端無線電頭，此時遠端無線電頭會做光電轉換，將光訊號轉換成電訊號後升頻至28GHz毫米波在各自對自己涵蓋範圍內的用戶設備(User Equipment, UE)進行服務，用戶設備再經由等化(Equalizer)與MIMO Decoder等訊號處理取得訊號服務。以此系統實現無線射頻與光纖通訊整合技術(Radio over Fiber, RoF)並提供未來第五代行動通訊(5th Generation Mobile Networks ,5G)眾多服務與應用。

In order to cope with fast growth of mobile communication network and the shortage of available spectrum, millimeter wave (MMW) sufficient spectral resources becomes indispensable part of 5G mobile network. Due to the physical characteristics of millimeter wave, the transmission distance is not far, so as to 5G needs to build base stations (small cells) widely in the future.
In centralized radio-over-fiber (RoF) fronthaul network architecture, dense deployment of small cells will encounter some problems in the scenario of downlink coordinated multipoint (CoMP), all associated BSs for CoMP need to allocate the same channel to a cell-edge user and this channel cannot be allocated to other users simultaneously. Thus, as the number of cell-edge users increases, the spectral efficiency of the system becomes worse.
In this paper, we propose and experimentally demonstrate NOMA combine CoMP concept for 5G MMW Fiber Wireless Integration Fronthaul System in centralized RoF fronthaul networks architecture. The experimental results show using NOMA-CoMP improved cell edge user quality, increased spectral efficiency and decreased small cell hardware cost. Transmitter provides a highly centralized architecture that uses joint processing (e.g., SFBC-CoMP coding) and resource sharing (e.g., clock and carrier frequency) in the baseband unit (BBU). Thus, the centralized architecture can save the cost of the entire system, which is beneficial to the future 5G dense deployment of small cells, and at the same time can ensure the synchronization of the signal. The signals are transmitted to each remote radio head (RRH) via optical fiber. At this time, the remote radio head will convert the optical signal into an electrical signal, and then up-converted to 28-GHz millimeter wave to serve the user equipment (UE). On the UE side, user obtains signal services through digital signal processing (DSP) such as equalizer and MIMO decoder. This system realizes RoF technology which provides many services and applications for 5G mobile network in the future.

中文摘要 i
ABSTRACT ii
致謝 iii
圖目錄 vi
表目錄 ix
第1章 緒論 1
1.1 前言 1
1.2 研究動機與目的 4
1.3 論文架構 5
第2章 正交分頻多工與元件原理 6
2.1 正交分頻多工 6
2.2 馬赫詹德調變器 10
2.3 光學波長間隔器 12
2.4 光學耦合器 13
2.5 光檢測器與直接檢測光學正交分頻多工系統機制 14
第3章 非正交多重存取技術 17
3.1 非正交多重存取技術原理 17
3.2 疊加編碼 20
3.3 連續消除干擾 22
第4章 多點協作與多天線系統 24
4.1 多點協作基本概念 24
4.2 多天線通訊系統 32
4.3 空頻區塊編碼 35
4.3.1 SFBC Encoder 36
4.3.2 SFBC Decoder MISO 38
4.3.3 SFBC Decoder MIMO 40
第5章 NOMA-CoMP 傳送與接收 42
5.1 NOMA-CoMP 傳送端 42
5.2 NOMA-CoMP 接收端 44
5.2.1 NOMA-CoMP Decoder(SISO) 44
5.2.2 NOMA-CoMP Decoder(MISO) 47
5.2.3 NOMA-CoMP Decoder(MIMO) 48
第6章 NOMA-CoMP實驗設置與結果 49
6.1 光纖無線整合前傳網路 49
6.2 NOMA-CoMP 實驗設置 51
6.3 NOMA-CoMP實驗結果 55
6.3.1 Compare NOMA with SFBC to without SFBC 55
6.3.2 Compare Tx diversity to Rx diversity 59
6.3.3 Near User move 1m to 2m 64
6.3.4 Received Optical Power vs BER (Power Ratio fixed 4) 66
第7章 結論 70
參考文獻 71

[1] 吳元熙(2019)，跟4G不一樣在哪？5G白話文快速看懂技術差異，網址: https://www.bnext.com.tw/article/54075/5g-4g-difference
[2] 维基百科编者，4G，维基百科，網址: https://zh.wikipedia.org/wiki/4G
[3] Sami TABBANE,“4G to 5G networks and standard releases”, 2019
[4] Christina Lim, Yu Tian, Chathurika Ranaweera, Thas Ampalavanapillai Nirmalathas, Elaine Wong, and Ka-Lun Lee, "Evolution of Radio-Over-Fiber Technology," J. Lightwave Technol. 37, 1647-1656 (2019)
[5] G. Chang and L. Cheng, "Fiber-wireless integration for future mobile communications," 2017 IEEE Radio and Wireless Symposium (RWS), Phoenix, AZ, 2017, pp. 16-18, doi: 10.1109/RWS.2017.7885932.
[6] J. Choi, "Non-Orthogonal Multiple Access in Downlink Coordinated Two-Point Systems," in IEEE Communications Letters, vol. 18, no. 2, pp. 313-316, February 2014, doi: 10.1109/LCOMM.2013.123113.132450.
[7] 鄒志偉(2011)，光纖通訊，台北市:五南圖書
[8] Wikipedia contributors,” Optical interleaver”,2020
[9] 维基百科编者，波長分波多工，维基百科，網址: https://zh.wikipedia.org/w/index.php?title=%E6%B3%A2%E5%88%86%E5%A4%8D%E7%94%A8&oldid=49416124
[10] W. Shieh, Q. Yang and Y. Ma, "High-speed and high spectral efficiency coherent optical OFDM," 2008 Digest of the IEEE/LEOS Summer Topical Meetings, Acapulco, 2008, pp. 115-116, doi: 10.1109/LEOSST.2008.4590516.
[11] Arthur James Lowery, "Amplified-spontaneous noise limit of optical OFDM lightwave systems," Opt. Express 16, 860-865 (2008)
[12] Y. Tian, K. Lee, C. Lim, and A. Nirmalathas, "Demonstration of Non-Orthogonal Multiple Access Scheme using Multilevel Coding without Successive Interference Cancellation with 60 GHz Radio-over-Fiber Fronthaul," in Optical Fiber Communication Conference, OSA Technical Digest (online) (Optical Society of America, 2018), paper Tu3J.4.
[13] L. Lei, "From Orthogonal to Non-orthogonal Multiple Access: Energy-and
Spectrum-Efficient Resource Allocation," Linköping University Electronic Press,
2016.
[14] S. M. R. Islam, N. Avazov, O. A. Dobre and K. Kwak, "Power-Domain Non-Orthogonal Multiple Access (NOMA) in 5G Systems: Potentials and Challenges," in IEEE Communications Surveys & Tutorials, vol. 19, no. 2, pp. 721-742, Secondquarter 2017, doi: 10.1109/COMST.2016.2621116.
[15] R. Hoshyar, F. P. Wathan, and R. Tafazolli, “Novel low-density signature for synchronous CDMA systems over AWGN channel,” IEEE Trans.Signal Process., vol. 56, no. 4, pp. 1616–1626, Apr. 2008.
[16] M. Al-Imari, P. Xiao, M. A. Imran and R. Tafazolli, "Uplink non-orthogonal multiple access for 5G wireless networks," 2014 11th International Symposium on Wireless Communications Systems (ISWCS), Barcelona, 2014, pp. 781-785, doi: 10.1109/ISWCS.2014.6933459.
[17] H. Nikopour et al., “SCMA for downlink multiple access of 5G wireless networks,” in Proc. IEEE Glob. Telecommun. Conf. (GLOBECOM),Austin, TX, USA, Dec. 2014, pp. 3940–3945.
[18] S. Chen, B. Ren, Q. Gao, S. Kang, S. Sun and K. Niu, "Pattern Division Multiple Access—A Novel Nonorthogonal Multiple Access for Fifth-Generation Radio Networks," in IEEE Transactions on Vehicular Technology, vol. 66, no. 4, pp. 3185-3196, April 2017, doi: 10.1109/TVT.2016.2596438.
[19] S. Shen, Y. Chen, Q. Zhou, and G. Chang, "Demonstration of Pattern Division Multiple Access with Message Passing Algorithm in MMW-RoF Systems," in Optical Fiber Communication Conference (OFC) 2020, OSA Technical Digest (Optical Society of America, 2020), paper M2F.3.
[20] J. Zhang, S. Chen, X. Mu and L. Hanzo, "Evolutionary-Algorithm-Assisted Joint Channel Estimation and Turbo Multiuser Detection/Decoding for OFDM/SDMA," in IEEE Transactions on Vehicular Technology, vol. 63, no. 3, pp. 1204-1222, March 2014, doi: 10.1109/TVT.2013.2283069.
[21] Z. Ding, M. Peng and H. V. Poor, "Cooperative Non-Orthogonal Multiple Access in 5G Systems," in IEEE Communications Letters, vol. 19, no. 8, pp. 1462-1465, Aug. 2015, doi: 10.1109/LCOMM.2015.2441064.
[22] J. Shi, Y. Hong, J. He, R. Deng, and L. Chen, "Experimental Demonstration of OQAM-OFDM based MIMO-NOMA over Visible Light Communications," in Optical Fiber Communication Conference, OSA Technical Digest (online) (Optical Society of America, 2018), paper M2K.3.
[23] Yu Tian, Christina Lim, Ampalavanapillai Nirmalathas, and Ka-Lun Lee, "Multi-cell coordination for 60 GHz RoF fronthaul enabled by a non-orthogonal multiple access scheme without successive interference cancellation," Opt. Lett. 43, 4236-4239 (2018)
[24] Jin Shi, Yang Hong, Rui Deng, Jing He, Lian-Kuan Chen, and Gee-Kung Chang, "Demonstration of Real-Time Software Reconfigurable Dynamic Power-and-Subcarrier Allocation Scheme for OFDM-NOMA-Based Multi-User Visible Light Communications," J. Lightwave Technol. 37, 4401-4409 (2019)
[25] T. M. Cover, “Broadcast channels,” IEEE Trans. Inf. Theory, vol. 18,no. 1, pp. 2–14, Jan. 1972.
[26] M. Vaezi, Z. Ding, and H. V. Poor, Multiple Access Techniques for 5G Wireless Networks and Beyond, Springer, 2019.
[27] M. Sawahashi, Y. Kishiyama, A. Morimoto, D. Nishikawa and M. Tanno, "Coordinated multipoint transmission/reception techniques for LTE-advanced [Coordinated and Distributed MIMO]," in IEEE Wireless Communications, vol. 17, no. 3, pp. 26-34, June 2010, doi: 10.1109/MWC.2010.5490976.
[28] Coordinated Multi-Point Operation for LTE Physical Layer Aspects, 3GPP TR36.819, Dec. 2011.
[29] L. Cheng et al., "Coordinated Multipoint Transmissions in Millimeter-Wave Radio-Over-Fiber Systems," in Journal of Lightwave Technology, vol. 34, no. 2, pp. 653-660, 15 Jan.15, 2016, doi: 10.1109/JLT.2015.2480786.
[30] J. G. Proakis and M. Salehi, “Optimum receivers for AWGN Channels,”in Digital Communications, 5th ed. New York, NY, USA: McGraw-Hill,2008, pp. 160–289.
[31] B. S. Everitt, The Cambridge Dictionary of Statistics in Medical Sciences.
Cambridge, U.K.: Cambridge Univ. Press, 1998.
[32] Weihong Fu and Weidong Kou, "A new look at coding and decoding algorithm for SFC-OFDM system," 19th International Conference on Advanced Information Networking and Applications (AINA'05) Volume 1 (AINA papers), Taipei, Taiwan, 2005, pp. 91-94 vol.2, doi: 10.1109/AINA.2005.41.
[33] S. M. Alamouti, "A simple transmit diversity technique for wireless communications," in IEEE Journal on Selected Areas in Communications, vol. 16, no. 8, pp. 1451-1458, Oct. 1998, doi: 10.1109/49.730453.
[34] K. F. Lee and D. B. Williams, "A space-frequency transmitter diversity technique for OFDM systems," Globecom '00 - IEEE. Global Telecommunications Conference. Conference Record (Cat. No.00CH37137), San Francisco, CA, 2000, pp. 1473-1477 vol.3, doi: 10.1109/GLOCOM.2000.891885.
[35] L. Cheng, M. M. U. Gul, A. Ng'oma, Feng Lu, X. Ma and G. Chang, "High-diversity millimeter-wave CoMP transmission based on centralized SFBC in radio-over-fiber systems," 2015 Optical Fiber Communications Conference and Exhibition (OFC), Los Angeles, CA, 2015, pp. 1-3.
[36] C. Lim et al., "Fiber-Wireless Networks and Subsystem Technologies," in Journal of Lightwave Technology, vol. 28, no. 4, pp. 390-405, Feb.15, 2010, doi: 10.1109/JLT.2009.2031423.