由於全球龐大的需求，現今通訊科技廣泛的發展；例如:非同步數位用戶專線(ADSL)、無線保真(Wi-Fi)與高畫質電視(HDTV)。

我們追求高品質、高良率的通訊技術。正交分頻多工(OFDM)的技術吸引著眾人的目光，這是因為正交分頻多工令人著迷的優點不僅在長距離傳輸上有高比特率(bit rate)而且具備可重配置的網路系統。再者，利用了循環字首(Cyclic prefix)對抗符際干擾(Inter-symbol Interference ISI)進而減少對系統的損害。

在本篇論文中，首先我將會概括地介紹光纖通訊的需求，緊接著的是解釋本篇論文的實驗動機以及組織。其次討論理論上的研究其中包含了數學構想、基本原理中的一階等化器(one tap equalizer)、循環字首(cyclic prefix)以及訓練符號的同步(training symbol synchronization)。此外成功建立實驗架構和實現一階等化器與訓練符號同步的作用，而系統的性能也已著手量測完畢進而展示整個系統結果並且討論。最後則是本篇論文的結論。

Nowadays the technologies of communication are widely developing due to the huge requirements in the world, such as asymmetric digital subscriber line (ADSL), wireless fidelity (Wi-Fi), and high definition television (HDTV).
We are seeking for high performance and quality communication schemes. The scheme of orthogonal frequency division multiplexing (OFDM) catches everyone's eyes due to the advantages of the OFDM. Not only high bit rate in the long haul transmission but also reconfigurable network is the charming contention, and the penalties are reduced by the cyclic prefix which can reduce the inter-symbol interference (ISI).
In this thesis, I will introduce the demand for optical fiber communications, then, interpret the motivation and the organizations in a nutshell. Next, the theoretical studies will be discussed, including mathematical formulations and basic theories of one tap equalizer, a cyclic prefix, a training symbol synchronization, and a discrete multitone (DMT) modulation. In addition, the experimental setups are successfully constructed and used for verifying the impact of one tap equalizer and the training symbol synchronization. Also, the performance of the systems are measured. Finally, the thesis is concluded.

致謝 i
中文摘要 ii
Abstract iii
Contents iv
1 Introduction 1
1.1 Introduction of Optical fiber communication 1
1.2 Motivation of the Thesis 3
1.3 The Organizations of the Thesis 4
References of Chapter 1 5
2 Theoretical Study of OFDM System 7
2.1 Introduction 7
2.2 Mathematical Formulation of an OFDM Signal 8
2.2.1 Cyclic Prefix for OFDM System 11
2.2.2 Mapping Format 12
2.2.3 Fast Fourier Transform Implementation of OFDM System 13
2.3 OFDM Transmitter 15
2.4 OFDM Receiver 17
2.4.1 Symbol Synchronization 18
2.4.2 One Tap Equalizer 19
2.5 Discrete Multi-tone Modulation 20
2.6 Coding for OFDM 22
2.6.1 Coding for OFDM Transmitter 23
2.6.2 Coding for OFDM Receiver 24
Attachment of chapter 2 26
References of Chapter 2 31
3 Experimental Study of OFDM System 33
3.1 Introduction 33
3.2 Experimental Setup 35
3.2.1 Experimental Setup of BTB 35
3.2.2 Experimental Setup of BTB with Noise Loading 38
3.2.3 Experimental Setup of In Line Transmission 39
3.2.4 Experimental Setup of In Line Transmission with Noise Loading 40
3.3 Results of Experiments 41
References of Chapter 3 47
4 Conclusions 49

List of Abbreviations vi

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