臺灣博碩士論文加值系統

在本論文中，我們提出一個新型的多輸入多輸出分碼多工接收機，在傳送端採用了混合式前置編碼，這個混合式前置編碼的方式經由適當的設計不僅能用來對抗因為多重路徑環境所產生的符碼間干擾，而且也能夠用來萃取出通道的相位資訊，這在傳統的盲蔽式接收機是做不到的，而在此架構下我們採用線性限制條件常模法則設計此接收機的濾波器組，並為了減少計算複雜度，採用廣義旁波帶消除器之架構配合遞迴式最小平方值演算法來實現我們所提出的適應性線性限制條件常模多輸入多輸出分碼多工濾波器組，並且同時使用梯度法來同時追蹤主要用戶之振幅。最後透過電腦模擬，可知我們所提出的架構比起一般傳統架構來的優越，並且可知比起傳統的盲蔽式卡彭接收機，我們所提出的架構能夠更有效抵抗對於針對主要用戶做同步時所產生之時間誤差問題。

In this thesis, we present a new hybrid pre-coded direct-sequence code division multiple access (DS-CDMA) system framework that use the multiple-input multiple-output (MIMO) antennas along with Alamouti’s space-time block code (ST-BC). In the transmitter, the idea of hybrid pre-coded is exploited. It not only used to counteract the inter-symbol interference (ISI) introduced by the channel fading duo to multipath propagation but also very useful for exacting the phase of channel by appropriate design, which is not adopted in the conventional blind receiver. Under this structure, we propose a new blind adaptive MIMO-CDMA receiver based on the linearly constrained constant modulus (LCCM) criterion. To reduce the complexity of receiver design, framework of the generalized sidelobe canceller (GSC) associated with the recursive least square (RLS) algorithm is adopted for implementing the LCCM MIMO-CDMA receiver, and use gradient method to track the desired user’s amplitude, simultaneously. Via computer simulations, advantages of the proposed scheme will be verified. Compared to the conventional blind Capon receiver, we will show that the performance of the proposed scheme is more robust against inaccuracies in the acquisition of the desired user’s timing.

Acknowledgements i

Abstract ii

Contents iii

List of Figures v

List of Tables vii

Chapter 1
Introduction 1

Chapter 2
Conventional Blind Capon Receiver for Space-Time Block Coded MIMO-CDMA Systems 7
2.1 Introduction 7
2.2 Review of Space-Time Block Code (ST-BC) 7
2.3 Downlink Space-Time Block Coded MIMO-CDMA in Frequency-Flat Channels 11
2.4 MMSE Receiver and Blind Capon Receiver 16
2.5 Phase Ambiguity associated with Blind Channel Estimation 20


Chapter 3
Blind Adaptive Constant Modulus GSC-RLS Algorithm for Hybrid Pre-coded ST-BC MIMO-CDMA Receiver in Multipath Channels 22
3.1 Introduction 22
3.2 Hybrid Pre-coded ST-BC MIMO-CDMA Receiver In Multipath Channels 23
3.3 MIMO CM-GSC-RLS Algorithm with Capon Channel Estimation 33
3.4 Method to Resolve the Problem of Phase Ambiguity 39
3.5 Signal Model in Time-Varying Channels 40

Chapter 4
Simulation Results 43
4.1 Preliminaries 43
4.2 Simulation Results and Some Observations 44

Chapter 5
Conclusions 53

Appendix A
Method of Selecting in MIMO CM-GSC-RLS Algorithm 55

Appendix B
Adaptive Implementation of Blind Capon Receiver (MIMO MV-GSC-RLS Algorithm) 58

References 63

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