整合光有線與無線網路技術之研究

Research of the Convergent Optical Wired and Wireless Networking Technologies

許勁崴(Chin-Wei Hsu)

指導教授 ： 鄒志偉

國立交通大學/電機學院/光電工程系所/博士(2018年)

摘要

在本論文中我們將簡介以及實驗驗證一些光有線以及無線通訊技術，光有線傳輸技術主要用於接取或是資料中心網路，而光無線通訊技術主要用於室內資料傳輸，本論文將針對這些技術進行模擬分析並解決其所面臨的問題。
於光有線傳輸系統中，直接接收(Direct detection)的全光正交分頻多工(O-OFDM)系統使用單一雷射光源產生多個波長同調光載波，我們針對光載波調變器(opt-comb-MOD)以及資料調變器(data-MOD)分別進行模擬分析並優化此系統，除此之外，O-OFDM系統接收端使用光學濾波器來解調各載波的資料，不同型態的濾波器對於訊號品質有重大影響，本論文中亦針對各種濾波器進行分析比較，選擇最佳濾波器提升傳輸訊號品質。
於光無線通訊中，我們提出並實驗使用白光LED燈為光源的可見光通訊系統，由於可見光通訊系統(Visible light communication)的傳輸速率受限於白光LED的調變頻寬，一般白光LED的調變頻寬約為2~3 MHz，為了突破此限制，本論文提出使用等化器(Equalizer)電路增加調變頻寬並使用正交分頻多工調變格式來增加頻譜效率，此外，我們亦使用多輸入多輸出(MIMO)解調技術使系統整體傳輸容量更進一步提升。在可見光通訊系統中訊號強度過大時會有非線性失真產生，我們採用了Volterra非線性等化器來消除此失真。除了用於室內高速傳輸之外，可見光通訊技術亦可用於室內定位系統。本論文中我們將提出並實驗展示使用太陽能板作為光接收器的可見光定位系統，另外，我們亦將機器學習(Machine learning)方法用於定位系統中，為了提升系統的定位精準度以及使系統對環境變化有更大的容忍度。
最後，有了前面所提出的這些光有線以及無線通訊傳輸技術，我們將其整合並用於接取網路與室內行動通訊網路之中，首先，我們結合了O-OFDM與毫米波(millimeter wave)光纖微波(Radio-over-fiber)的整合光有線與無線接取網路系統，此系統可同時支援多個光網路單元(Optical network unit, ONU)，並可選擇對應波長於遠程天線單元(Remote antenna unit, RAU)發送毫米波無線訊號。此外，於室內無線網路方面，我們提出結合射頻無線技術(Radio-frequency)，毫米波無線通訊以及可見光定位的整合室內無線通訊系統，充分利用各頻段資源使室內無線網路系統更加完善。

關鍵字

光纖通訊 ； 可見光通訊 ； 光纖微波 ； 室內定位

並列摘要

In this dissertation, we introduce and demonstrate several optical wired and wireless transmission technologies for the access or data center network and indoor wireless data transmission respectively.
For optical wired transmission system, a cost-effective DD O-OFDM system with multiple wavelength channels produced by single laser source is proposed and demonstrated. We also numerically analyze the requirements of the opt-comb-MOD (modulator used to generate the optical comb source) and the data-MOD (modulator used to generate the OOK data) in the system. Besides, different filter shapes for de-multiplexing the all-optical OFDM signal are compared and the numerical analysis shows the sinc-shaped de-multiplexer outperforms other de-multiplexers.
For optical wireless communication, the phosphor white LED based visible light communication is proposed and demonstrated. In order to achieve high speed data rate of the transmission, equalizer circuits are used to broaden the modulation bandwidth of the LED light and adaptive bit/power loading OFDM is utilized to enhance the spectral efficiency. In addition, 3×3 MIMO technique is applied to further increase the system capacity so that the total data rate of the system can achieve 1 Gbits/s over 1m transmission distance. For the purpose of mitigating the nonlinear distortion, Volterra nonlinear equalization (VNLE) is also introduced and demonstrated in the VLC system. Apart from the indoor high speed data transmission, VLC can also be used for indoor positioning. An energy-efficient indoor positioning system using solar-cell as a VLC detector is proposed and experimentally demonstrated. In addition, machine learning technique is also applied to the positioning system not only to improve the positioning resolution but also to make the system more tolerant to the changing of environment.
With the proposed optical wired and wireless communication technologies, we integrate the O-OFDM system with millimeter wave (MMW) radio-over fiber (ROF) for the convergent optical wired and wireless access networks. Furthermore, we propose another all-spectrum convergent wireless system, which utilizes the radio-frequency (RF) and proposed visible light positioning system to support the high throughput MMV data transmission for the indoor mobile networking.

並列關鍵字

Optical fiber communication ； Visible light communication (VLC) ； Radio-over-fiber (ROF) ； Indoor positioning

參考文獻

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