上鏈寬頻分碼多工系統之通道估測

Abstract

本論文主要是對第三代寬頻分碼多工通訊系統中的通道估測部分做整體的介紹。在同調寬頻分碼多工上鏈通訊系統中，週期性出現於控制通道中的導引信號被用來做通道估測。快速的傳輸功率控制及手機的省電在寬頻分碼多工上鏈通訊系統中是非常重要的課題。我們提出了移動平均的方法及滑動窗型平均的方法來減小控制訊號決定時間的延遲。根據控制通道及資料通道的資訊，我們得出一個低複雜度的通道估測方法來減小控制通道傳輸能量。經過整篇論文的探討及模擬，我們發現利用滑動窗型平均法六並根據控制通道及資料通道的資訊，在每個位元的錯誤率或延遲時間及功率節省上整體的表現可以得到較其他方法好的結果。

In this thesis, the channel estimation methods for next generation wideband code-division multiple-access (WCDMA) system were studied. Coherent WCDMA reverse link periodically transmitting pilot symbols in front of every control channel slot to estimate the fading channel is considered. For the WCDMA reverse link, fast transmit power control (TPC) and power saving of mobile station are the important issues. We proposed moving average method and sliding window methods to overcome the decision delay of the control symbols. We also proposed a low-complexity channel estimation method based on both control and data channels to reduce the required power of a control channel. After investigation and simulation in this thesis, we conclude that the sliding window type-VI channel estimation based on both control and data channels is better than other methods in the overall performance of BER, delay time and power reduction. 摘 要 I ABSTRACT II 誌 謝 III CONTENTS IV LIST OF TABLES VIII LIST OF FIGURES IX CHAPTER 1 INTRODUCTION 1 1.1 WIDEBAND CODE DIVISION MULTIPLE ACCESS TECHNIQUES 1 1.2 CONCEPT OF CHANNEL ESTIMATION AND RAKE RECEIVER 2 1.3 ORGANIZATION OF THE THESIS 4 CHAPTER 2 SYSTEM STRUCTURE 5 2.1 TRANSMITTER 5 2.1.1 Frame Structure 5 2.1.2 Spreading and Modulation 6 2.2 CHANNEL MODEL 10 2.2.1 Jakes Model 10 2.2.2 Doppler effect 11 2.2.3 Tapped-Delay-Line Model 12 2.3 STRUCTURE OF RECEIVER 13 2.3.1 Receiver Structure 13 2.3.2 Equivalent Receiver Structure 14 2.4 SYSTEM MODEL 16 2.4.1 Transmitter 16 2.4.2 Channel 16 2.4.3 Receiver 17 CHAPTER 3 CHANNEL ESTIMATION BASED ON CONTROL CHANNEL 20 3.1 INTRODUCTION 20 3.2 LINEAR INTERPOLATION 22 3.2.1 Linear Interpolation Method 22 3.2.2 Simulation Results 23 3.3 LEAST-SQUARE ALGORITHM 25 3.3.1 Introduction 25 3.3.2 Simulation Results 26 3.4 MAXIMUM LIKELIHOOD ESTIMATION 28 3.5 MOVING AVERAGE 29 3.5.1 Introduction 29 3.5.2 Simulation Results 30 3.6 SLIDING WINDOW 33 3.6.1 Sliding Window types 33 3.6.2 Sliding Window Based on Previous Data 34 3.6.3 Sliding Window Based on Previous Data and Future Data 35 3.6.4 Simulation Results 36 3.7 ANALYTICAL AND SIMULATION RESULTS 40 3.7.1 BER Performance 40 3.7.2 Delay Time 44 3.7.3 Computational Complexity 45 CHAPTER 4 CHANNEL ESTIMATION BASED ON BOTH CONTROL AND DATA CHANNELS 47 4.1 INTRODUCTION 47 4.2 OPTIMAL CHANNEL ESTIMATION BASED ON BOTH CONTROL AND DATA CHANNELS 48 4.3 THE LOW COMPLEXITY CHANNEL ESTIMATION ALGORITHM BASED ON BOTH CONTROL AND DATA CHANNELS 52 4.4 ANALYTICAL AND SIMULATION RESULTS 53 4.4.1 BER Performance 53 4.4.2 Delay Time 62 4.4.3 Computational Complexity 63 CHAPTER 5 CONCLUSIONS 64 REFERENCES 66 自 傳 69