在傳送資料之前，直接序列展頻通訊技術必需要進行頻率、框(Frame)、碼(Code)之同步。在這篇論文中，對於碼同步在3GPP/UTRA FDD WCDMA標準中所提供的通道模型做了些討論。論文一開始先對一般現有的擷取(Acquisition)方式做個介紹，其中包括解展頻(Despreading)方式和非同調後偵測積分器(Post-detection integration)的架構。然後對於已經擷取到的信號路徑(Path)後續追蹤和搜尋未找到的信號路徑提出處理方法。在多通道的通訊模型中，信號路徑管理是個重要的課題。這篇論文對於這方面也有所探討。最後，以I.I. Quatro6x DSP板實現碼同步理論之即時運算。

Direct sequence spread spectrum technology requires frequency, frame, and code synchronization between the transmitter and receiver before transmitting information data. In this thesis, code synchronization in the multipath channels specified by 3GPP/UTRA FDD WCDMA standard is discussed. First, conventional acquisition methods are overviewed, including various despreading methods and post-detection integration (PDI) schemes. Then the methods of tracking the obtained paths and searching new paths that are not found by acquisition are proposed. In the multipath channel, the path management is an important issue. This thesis has a discussion about this issue. Finally, these synchronization algorithms are implemented in the I.I. Quatro6x DSP card to realize the real-time processing of code synchronization.

Chapter 1 Introduction 1
1.1 Introduction 1
1.2 Transport Layer and Physical Layer in Dedicated Channels 4
1.2.1 Dedicated Channel 4
1.2.2 Dedicated Physical Channel 7
1.3 Scrambling Code and Channelization Code 10
1.3.1 Long Scrambling Code 10
1.3.2 Channelization Code 11
1.4 Modulation method of Dedicated Physical Channel 13
Chapter 2 Code Acquisition 15
2.1 Despreading Schemes 15
2.1.1 Active Correlator 16
2.1.2 Passive Correlator 17
2.1.3 Differential Code Matched Filter 17
2.2 Searching Strategies 18
2.2.1 Concept of Acquisition 18
2.2.2 Post-detection Integration (PDI) Schemes 20
Chapter 3 Acquisition Methods 22
3.1 Code Synchronization in W-CDMA System 22
3.2 Despreading Unit 23
3.3 Initial Acquisition 25
3.4 Advanced Acquisition 26
3.5 Threshold Setting Method 27
3.6 C Simulations 29
3.6.1 Performance of Acquisition 31
3.6.2 The Effect of Coarse Paths 35
3.6.3 The Effect of Noncoherent PDI 36
3.6.4 The Effect of Delta1 and Delta2 37
Chapter 4 Tracking and Searching of New Paths 42
4.1 Searching New Paths 42
4.2 Tracking the Obtained Paths 43
4.3 Rule of Updating FinePaths 45
(A) Step 1 46
(B) Step 2 48
4.4 C Simulations 50
4.4.1 Simulation 1 51
4.4.2 Simulation 2 52
4.4.3 Simulation 3 54
4.4.4 Other Simulations 57
4.4.5 Moving propagation conditions 63
Chapter 5 DSP Implementation 65
5.1 I.I. Quatro6x Hardware Introduction 65
5.1.1 FIFO Port I/O Expansion 68
5.1.2 FIFO Link I/O Expansion 70
5.2 Implementation of Speed and Memory Allocation 73
Chapter 6 Conclusion 81

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