臺灣博碩士論文加值系統

軟體無線電 (Software Defined Radio) 與正交分頻多工 (OFDM) 技術是當今兩個重要的通訊發展技術。在本篇論文中，我們首先探討在不同正交分頻多工系統底下的基本數位訊號處理技術，並且分析這些演算法所需要的硬體規格。基於整合通用的數位訊號處理技術以及這些技術個別的需求，我們提出一個適用於多標準的內接收機 (inner receiver) 架構。這個架構整合了四種現今主流的正交分頻多工系統，其中包含了數位電視廣播系統、數位音響廣播系統、無線區域網路系統 (IEEE 802.11a)以及無線都會網路系統 (IEEE 802.16a)。

Software defined radio (SDR) and orthogonal frequency division modulation (OFDM) are two key issues in the technology development of current and future communication systems. In this thesis, we first study basic signal processing techniques for various OFDM-based wireless communication systems and analyze their required computational specifications. Based on the adopted common signal processing techniques and the required specifications, a multi-mode inner receiver architecture is proposed. The proposed receiver integrates various mainstream OFDM-based inner receivers as one, including DVB-T, Eureka147, IEEE 802.11a and IEEE 802.16a.

Chinese Abstract………………………………………………… Ⅰ
English Abstract………………………………………………… Ⅱ
Acknowledgment…………………………………………………… Ⅳ
Content …………………………………………………………… Ⅴ
List of Tables ………………………………………………… Ⅷ
List of Figures ………………………………………………… Ⅸ
Chapter1 Introduction……………………………………………1
1.1 Background ………………………………………1
1.2 Organization of the Thesis……………………3
Chapter2 Introduction to OFDM-Based Systems………………4
2.1 Fundamentals of OFDM ………………………… 4
2.1.1 OFDM Model ……………………………………6
2.1.2 Guard Interval ………………………………8
2.2 DVB-T …………………………………………… 9
2.2.1 System Overview ……………………………9
2.2.2 Transmission Band ………………………11
2.2.3 Signal Expression and Frame Structure ……12
2.2.4 Reference Signals ……………………………13
2.3 Eureka 147 DAB System ……………………………15
2.3.1 System Overview …………………………16
2.3.2 Transmission Band…………………………………17
2.3.3 Signal Expression and Frame Structure……………18
2.3.4 Reference Signals …………………………20
2.4 IEEE 802.11a …………………………………20
2.4.1 System Overview …………………………20
2.4.2 Transmission Band ……………………22
2.4.3 Signal Expression and Frame Structure …………22
2.4.4 Reference Signals ………………………24
2.5 IEEE 802.16a…………………………25
2.5.1 System Overview…………………25
2.5.2 Frame Structure ……………………………27
2.5.3 Reference Signal ……………………28
Chapter3 SDR Designs for Inner Baseband OFDM Receivers …31
3.1 Integrated Design of Symbol Timing Detection………31
3.1.1 IEEE 802.11a ……………………………………………31
3.1.2 DVB-T, IEEE 802.16a & DAB …………………………33
3.1.3 SDR Integration Consideration …………35
3.2 Integrated Design of Frequency Offset Detection …36
3.2.1 Fractional Frequency Offset Detection……………37
3.2.2 Integral Frequency Offset Detection………………37
3.2.3 SDR Integration Consideration………………………40
3.3 Integrated Design of Frame Timing Detection ……42
3.3.1 IEEE 802.11a ……………………………………42
3.3.2 Eureka 147 DAB ………………………44
3.3.3 DVB-T …………………………………44
3.3.4 SDR Integration Consideration ……45
3.4 Channel Estimation………………………46
3.4.1 IEEE 802.11a …………………………45
3.4.2 DVB-T & IEEE 802.16a ………………………47
3.4.3 SDR Integration Consideration …………50
Chapter4 Integrated SDR Design for Wireless
OFDM Communication Systems…………………51
4.1 Receivers for Individual Systems……………51
4.1.1 IEEE 802.11a ……………………51
4.1.2 DVB-T …………………………………52
4.1.3 Eureka 147 DAB ………………………54
4.1.4 IEEE 802.16a …………………………55
4.2 Multi-mode Option…………………55
4.3 Proposed Multi-mode Inner Receiver Architecture …59
4.3.1 Symbol & Frequency Offset Detection ………62
4.3.2 Integral Frequency Offset Detection……………67
4.3.3 Frame Detection………………………………71
4.3.4 Channel Estimation …………………………74
4.4 Conclusion …………………………………75
Chapter5 Verilog Implementation……………80
5.1 Implementation Background …………………80
5.2 Mode Arrangement ……………………………80
5.3 Time-Domain Synchronizer ………………………81
5.4 Frequency-Domain Synchronizer ……………82
Chapter6 Conclusion ………………84
References…………………………………………86

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