電機資訊學院: 電信工程學研究所指導教授: 馮世邁顏偉平Yen, Wei-PingWei-PingYen2017-03-062018-07-052017-03-062018-07-052016http://ntur.lib.ntu.edu.tw//handle/246246/276673正交分頻多工以及基於正交分頻多工的系統在現代通訊系統中非常有用且常見。他們已經被許多標準所採納。然而，基於正交分頻多工的系統對於一些類比前端的直接轉換器所造成的非理想性非常敏感。在這個論文中，我們會考慮兩個效應，包含載波頻率位移以及實虛部非協調。這兩個效應會破壞子載波之間的正交性而導致載波間的干擾，這會使得系統的效能嚴重下降。所以，這些效應的估測及補償是非常重要的。 過去已經有一些研究人員研究過在正交頻分多址系統中載波頻率位移的問題。其中，「音樂估測器」以及「藉由轉動不變性技術之訊號參數估測」已經被提出應用在梳狀類型的正交頻分多址系統中。基於上述兩個估測器，我們在這篇論文中提出了兩個實虛部非協調的估測器以及實虛部非協調與載波頻率位移之同估測。此外，我們也把「音樂估測器」延伸到混合類型的正交頻分多址系統中。最後，我們執行了一些數值實驗來展示估測器的效能。The orthogonal frequency division multiplexing (OFDM) system and OFDM-based systems are very useful and common in modern communications. They have been adopted in many standards. However, OFDM-based systems are sensitive to some non-idealities caused by the direct-conversion receivers at analog front-end. In this thesis, we focus on two effects, carrier frequency offset (CFO) and in-phase and quadrature-phase (I/Q) imbalance. The CFO and I/Q imbalance destroy the orthogonality among subcarriers and result in inter-carrier interference(ICI), which would seriously degrade the performance of the system. So, estimation and compensation of these effects are important. In the past, the problem of CFO estimation in orthogonal frequency division multiple access (OFDMA) systems have been studied by a number of researchers. In particular, the MUSIC estimator and ESPRIT estimator have been proposed for comb-type OFDMA systems. In this thesis, based on the MUSIC and ESPRIT methods, we propose two I/Q imbalance estimators and joint estimation of I/Q imbalance and CFO. In addition, we also extend the MUSIC estimator for Hybrid OFDMA scheme, which is a combination of the comb-type and block-type OFDMA schemes. Moreover, numerical experiments are carried out to show the performance of our method.1129103 bytesapplication/pdf論文公開時間: 2016/8/25論文使用權限: 同意有償授權(權利金給回饋學校)正交頻分多址系統實虛部非協調載波頻率位移OFDMAI/Q ImbalanceCarrier Frequency Offsetthesis10.6342/NTU201601716http://ntur.lib.ntu.edu.tw/bitstream/246246/276673/1/ntu-105-R03942055-1.pdf