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A study on Blind Frequency and Timing Synchronization in OFDM Systems

orthogonal frequency division multiplexing (OFDM) systems are very sensitive to synchronization errors. Therefore, OFDM systems require the knowledge of symbol timing and frequency offset. Most OFDM synchronization algorithms proposed in the literature are data-aided estimation structures. Data-aided estimators use pilot symbols or training sequences to perform synchronization. However, the use of training data reduces the transmission data rate. The alternative, which we consider in this thesis, is nondata-aided methods that perform synchronization by utilizing the redundant guard interval or cyclic prefix. Recently, cyclo-stationarity of signals is applied for estimating synchronization error. Gini and Giannakis utilized the property for single carrier systems and Bolcskei applied the property for OFDM systems.
In this thesis, we proposed a modified synchronization algorithm, which is extended from Giannakis and Bolcskei algorithms, in additive white Gaussian noise (AWGN) environment. According to Park¡¦s study, additional sub-carrier weightings are not needed to enhance the estimation performance. From simulation results, the proposed modified blind synchronization algorithm can achieve better performance.

Identiferoai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0910109-150938
Date10 September 2009
CreatorsChou, Yung-chung
ContributorsJih-ching Chiu, Jieh-chian Wu, Ming-de Shieh, Ching-piao Hung, Ju-ya Chen
PublisherNSYSU
Source SetsNSYSU Electronic Thesis and Dissertation Archive
LanguageCholon
Detected LanguageEnglish
Typetext
Formatapplication/pdf
Sourcehttp://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0910109-150938
Rightsnot_available, Copyright information available at source archive

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