指導教授：馮世邁臺灣大學：電信工程學研究所胡煦佳Hu, Hsu-ChiaHsu-ChiaHu2014-11-302018-07-052014-11-302018-07-052014http://ntur.lib.ntu.edu.tw//handle/246246/264254Orthogonal frequency division multiplexing (OFDM) has recently received considerable interest for its advantages in high-bit-rate transmissions over frequency-selective fading channels. Space-time block coding (STBC) has emerged as a powerful approach to exploit spatial diversity and to combat fading in multiple-input multiple-output (MIMO) wireless communication systems. However, OFDM systems with direct-conversion RF receivers are very sensitive to non-idealities at the front-end of receiver, such as I/Q imbalance and carrier frequency o↵set (CFO). These non-idealities at the receiver result in intercarrier interference (ICI). Accurate estimates of the non-idealities and channel response are required in OFDM systems. This thesis studies the blind CFO and I/Q imbalance estimation for OFDM systems with multiple transmit antennas. The thesis consists of three parts. In the first part, we review an existing CFO and I/Q imbalance estimation method based on rank criterion. This method though gives good performance but not for joint estimation, it cannot estimate the I/Q imbalance in the presense of CFO. In order to solve this issue, we propose an improved method. In the second part, we propose a new rank criteron and group method for joint CFO and independent I/Q imbalance estimation. The proposed method exploits the redundant information in OSTBC for joint blind CFO and I/Q imbalance estimation. In the third part, we extend the proposed method to the estimation of frequency dependent I/Q imbalance in the presence of CFO. We also provide numerical simulation to verify the performance of the proposed methods.List of Tables vii List of Figures viii Abstract xiii Acknowledgements xv 1 Introduction........................................................... 1 2 I/Q Imbalance and Carrier Frequency Offset in OFDM Systems............. 5 2.1 Introduction to OFDMSystems.......................................... 6 2.2 Orthogonal STBC MIMO-OFDM Systems Model.............................. 10 2.3 The Phenomenon of I/Q Imbalance and CFO ............................. 11 2.4 I/Q Imbalance and CFO on the Received Baseband Signal Model.......... 12 2.5 Compensation of I/Q Imbalance and Carrier Frequency Offset........... 15 2.6 Simulation Result and Comparison .................................... 18 2.7 Concluding Remark.................................................... 21 3 Review of Blind I/Q Imbalance and CFO Estimation in OSTBC-OFDM Systems. 23 3.1 Review of OSTBC-OFDM Systems with 3 Transmit Antennas................ 24 3.2 Blind CFO Estimation Algorithms Based on Rank Criterion.............. 28 3.2.1 Proposed CFO Estimation Method Using Rank Criterion................ 28 3.2.2 SimulationResultandComparison ............... 30 3.3 Blind I/Q Imbalance Estimation Algorithms Based on Rank Criterion 33 3.3.1 Blind Estimation for Independent I/Q Imbalances . . . . . . . 33 3.3.2 Blind Estimation for Dependent I/Q Imbalances . . . . . . . 34 3.3.3 SimulationResultandComparison ............... 36 3.4 ConcludingRemark............................ 41 4 Joint Blind Estimation of I/Q Imbalance and CFO in OSTBC-OFDM Systems 43 4.1 Blind Independent I/Q Imbalance Estimation with CFO Based on RankCriterionandGroupMethod ................... 44 4.2 Blind CFO Estimation with Independent I/Q Imbalance Compensation BasedonRankCriterion......................... 51 4.3 SimulationResultandComparison ................... 52 4.4 ConcludingRemark............................ 60 5 Joint Blind Estimation of Frequency Dependent I/Q Imbalance and CFO in OSTBC-OFDM Systems 61 5.1 Blind Frequency Dependent I/Q Imbalance Estimation with CFO . . 62 5.1.1 ProposedSearchMethod..................... 64 5.1.2 ProposedIterativeMethod.................... 65 5.2 SimulationResultandComparison ................... 70 5.3 ConcludingRemark............................ 86 6 Conclusion 87 Bibliography 891748365 bytesapplication/pdf論文公開時間：2015/08/08論文使用權限：同意有償授權(權利金給回饋學校)正交分頻多工系統載波偏移實虛部非協調空時編碼thesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/264254/1/ntu-103-R01942063-1.pdf