為了因應行動通訊傳輸量的迅速增長，光學毫米波(MMW)是5G高速接取網路的一項關鍵技術。許多無線網路運營商著重於行動網路前段的網絡架構，其優點是具有集中的控制管理以及優化的服務品質。在行動網路前段中，如何以成本效益高的方式將新佈放的天線端與現有的中央機房做緊密的結合，並用於無線-光纖整合網路，是一項重要的課題。然而，目前在5G行動網路前段上行所提出的MMW產生與接收方式，都是以高頻元件為主。但是高頻元件會帶來許多本質上的問題，例如較高的熱雜訊、及昂貴的價格等。
為了解決這個問題，本論文以5G行動網路前段上行為基底，提出了以低頻寬元件來產生與接收MMW的解決方案。第一，設計一個於中央機房的接收端架構，利用光學降頻的方式，以低於12GHz頻寬的元件來接收30GHz的MMW信號。第二，在傳輸端利用10GHz半導體雷射的兩個不同的非線性動態模態 : 週期一(Period 1)和穩定鎖定(Stable Locking)來產生MMW信號，取代傳統的直接調變。利用以上兩種方式，以低頻寬元件完成MMW信號的產生與接收，將有效的降低建置及營運成本，並且減輕系統複雜度。
在本篇論文中，MMW信號形式以OFDM為主，將不同調變模式的MMW信號經由單模光纖傳輸B2B和25公里，無線傳輸0.3公尺、1公尺和1.5公尺的情況下進行量測與探討，以驗證提出架構之可行性。

To cope with the surging growth of internet mobile traffic and wireless services, optical millimeter wave (MMW) is a key technology to promote radio-frequency-over-fiber (RFoF) to become a promising solution for the next generation 5G high-speed access networks. Thus most wireless operators focus on mobile fronthaul (MFH) network architecture featuring a centralized controlling and managing with optimized service quality. In such MFH networks one major challenge is to seamlessly integrate the abundant newly deployed remote radio head (RRH) with the existing central offices (COs) for hybrid optical-wireless MMW service in a cost-effective manner. However, devices with high bandwidth seem to be the only approach to transmit and receive the optical MMW signal at MFH uplink in 5G hybrid fiber-wireless systems. Unfortunately, many sticky problems arise from high bandwidth devices in receivers, such as limited noise preventions and huge construction expenditure.
To resolve this dilemma, we propose a novel solution to appropriately transmit and receive MMW signals featuring with low bandwidth components in this work. We firstly design a receiver architecture to receive 30 GHz MMW uplink in COs but with beneath 12 GHz bandwidth devices mainly based on an optical frequency conversion, and secondly we utilize two different nonlinear dynamic patterns of a 10 GHz semiconductor laser, period-1 and stable locking, to generate uplink MMW signals instead of direct modulation via high bandwidth modulator. Hence, the employed components are all with a bandwidth requirement below 12 GHz, which leads to an effective cost reduction and relieve system complexity. In this work, a back-to-back and a 25-km single mode fiber transmission with 0.3-m, 1-m and 1.5-m wireless transmission scenarios are experimentally demonstrated with various modulation formats.

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