超寬頻 (UWB) 脈波無線電系統因其低功率，不需載波及多重路徑多樣性等優點，近來受到廣泛的注意。在許多的調變及多工技術當中，本文探討直序 (DS) 二位元相移 (BPSK) 調變使用於下鏈多重路徑干擾通道。我們首先概述同步DS-UWB 系統吸引人之特性並且據以設計一低複雜度之RAKE 行動台 (MS)接收機。然而，由於準確的通道訊息是可靠解調之決定因素，因此本文提出一盲蔽式 (不需數據幫助) 通道估計器。我們進行性能評估以驗證通道估計法則之準確度 (以均方根誤差為衡量標準) 以及盲敝式行動台接收機之可靠度 (以位元錯誤率為衡量標準)。

Ultra wideband (UWB) impulse radio (IR) system has currently being considered for several applications due to its attractive features that include low-power carrierless and ample multipath diversity. The various modulation and multiple access schemes. In this thesis deals with direct sequence (DS) binary phase shift keying (BPSK) modulation operating in the presence of multipath fading downlink channel. We first outline the attractive properties of the synchronous DS-UWB scheme and design a low-complexity RAKE mobile station (MS) receiver. However, since accurate channel information is crucial for reliable operation, thereby we propose a blind (non-data aided) channel estimator. Performance evaluations are conducted to demonstrate the accuracy (in terms of root mean square error) of the proposed channel estimation algorithm and the reliability (in terms of bit error rate) of the blind MS receiver.

Contents

中文摘要 iii
Abstract iv
誌謝 v
Contents vi
List of figures viii

Chapter 1 Introduction 1
1.1 Background 1
1.2. Research methods 1
1.3 Content Outline 2
Chapter 2 Spread spectrum communication techniques 3
2.1 Direct-sequence spread spectrum (DSSS) 3
2.1.1 DSSS transmission method 3
2.1.2 Benefits of DSSS 5
2.1.3 BPSK DSSS 6
2. 2 PN Code 8
2.2.1 Walsh code 10
2.3 Rake receiver 11
2.4 DS-CDMA 13
Chapter 3 Introduction UWB IR techniques 15
3.1 UWB IR Introduction 15
3.1.1 Key benefits of UWB 15
3.1.2 UWB and Shannon’s theory 16
3.1.3 UWB definition 18
3.1.4 UWB applications 19
3.2 Signal model of UWB IR (Single user) 20
3.2.1 BPAM 21
3.2.2 BPPM 21
3.3 Signal model of UWB IR (Multi user) 22
3.3.1 Time-Hopping PAM modulation 22
3.3.2 Time-Hopping PPM modulation 23
3.4 Multipath 24
Chapter 4 Blind signal reception scheme 27
4.1 UWB-IR Signal model 28
4.1.1 DS-UWB(Direct Sequence UWB) 29
4.2 RAKE receiver 33
4.3 Blind channel estimation algorithm 36
Chapter 5 Performance evaluation 40
Chapter 6 Conclusion 44
References 45
Appendix A : (Proof ’s eigenvalues) 47
Appendix B(Proof (28)) 48

References
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