指導教授：馮世邁臺灣大學：電信工程學研究所陸柏勳Lu, Po-HsunPo-HsunLu2014-11-302018-07-052014-11-302018-07-052014http://ntur.lib.ntu.edu.tw//handle/246246/264282Orthogonal frequency division multiplexing (OFDM) has recently received considerable interest for its advantages in high-bit-rate transmissions over frequency-selective fading channels. Recently, research on wireless relay networks becomes popular because of the following reasons. When a transmitter and a receiver are unable to communicate with each other because of the distance between them or fading of the channel, they can be connected by one or multiple relay nodes to create an alternate route. Relay transmission can enhance the reliability, increase the rate in wireless networks. Relay transmission provides an effective means of improving spectral and power efficiency. In addition, the use of multiple antennas to achieve transmit diversity in the cellular uplink is impractical due to the size constraints at each mobile. Cooperative communication can overcome this constraint problem. Relay nodes cooperate with terminals of the users when each relay nodes transmit its own information to destination by processing the information from source. This thesis studies the blind channel estimation for amplify-and-forward(AF) TWRN ZP-OFDM systems. We will show how to apply the subspace-based blind channel estimation algorithm for the case of TWRN ZP-OFDM systems. Pilots for estimating the scalar ambiguity in blind channel estimation are also derived. Simulations are carried out to verify the performance of the proposed method. Compared with the existing blind channel estimation method in TWRN, our proposed method has a better performance.Contents List of Figures vii Abstract ix Acknowledgements xi 1 Introduction 1 2 OFDM and Relay Network Systems 5 2.1 Introduction to OFDM Systems . . . . . . . . . . . . . . . . . . . . . 6 2.2 Introduction to Relay Network Systems . . . . . . . . . . . . . . . . . 13 3 Subspace-Based Blind Channel Estimation in OFDM Systems and Relay Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.1 Review of Blind Channel Estimation Algorithm Using Few Received Blocks [20], [22] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3.2 Noise Weighting Matrix [22] . . . . . . . . . . . . . . . . . . . . . . . 21 3.3 Simulation Results and Comparison . . . . . . . . . . . . . . . . . . . 23 3.4 Concluding Remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 4 Blind Channel Estimation for OFDM Modulated Two-Way Relay Network . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 4.1 Review of Channel Estimation in Two-Way Relay CP-OFDM Systems [18] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 4.1.1 Least-Squares(LS) Estimate of T . . . . . . . . . . . . . . . . 33 4.1.2 Pilots for Removing The Ambiguity T . . . . . . . . . . . . . 33 4.2 Proposed Modi ed Channel Estimation Method in Two-Way Relay ZP-OFDM Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 4.3 Simulation Results and Comparison . . . . . . . . . . . . . . . . . . . 35 4.4 Concluding Remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 5 Proposed Blind Channel Estimation in Two-Way Relay ZP-ODFM Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 5.1 Blind Channel Estimation in Two-Way Relay ZP-OFDM Systems . . 42 5.2 Pilots for Removing Scalar Ambiguity . . . . . . . . . . . . . . . . . . 46 5.3 Simulation Results and Comparison . . . . . . . . . . . . . . . . . . . 48 5.4 Concluding Remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . 52 Bibliography 59888426 bytesapplication/pdf論文公開時間：2014/08/17論文使用權限：同意有償授權(權利金給回饋學校)正交分頻多工中繼系統通道盲估測thesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/264282/1/ntu-103-R01942102-1.pdf