正交分頻多重存取系統下頻率同步之研究

Study of frequency synchronization for OFDMA systems

金煜舜(Yu-Shun Chin)

指導教授 ： 王瑞騰

國立暨南國際大學/科技學院/通訊工程研究所/碩士(2010年)

摘要

在本篇論文中，我們研究頻率同步的議題在可以提供多使用者同時傳輸的服務而被視為未來無線通訊核心技術的正交分頻多重存取系統上。載波間干擾和多重存取干擾由於多重載波頻率偏移破壞了正交分頻多重存取系統的子載波正交性。所以，我們使用數個方法去壓制載波間干擾以及多重存取干擾的影響，使正交分頻多重存取可以達到良好頻率同步。我們由模擬結果發現最小平方法與最小均方誤差法的效能在位元錯誤率上比其他方法好。同時，我們經由一些運算發現他們擁有比其他方法較低的複雜度。

關鍵字

正交分頻多重存取 ； 頻率同步 ； 子載波頻率偏移 ； 最小平方法 ； 最小均方誤差法

並列摘要

In this thesis, we study the frequency synchronization for the orthogonal frequency division multiple access (OFDMA) system, which can support simultaneous multi-user
transmission and is regarded as the core technique in future wireless communications. The effects of inter-carrier interference (ICI) and multiple access interference (MAI) due to multiple carrier frequency offsets (CFO) will destroy the sub-carrier orthogonality of the OFDMA system. Therefore, we use several methods to suppress the effects of ICI and MAI so that good frequency synchronization of the OFDMA system can be achieved. We found from simulation results that the least square (LS) method and the minimum mean square error (MMSE) method result in better performance (in BER) than other methods,also, we found from some evaluations that they have lower complexity than other methods.

並列關鍵字

Orthogonal Frequency-Division Multiple Access(OFDMA) ； frequency synchronization ； carrier frequency offsets (CFO) ； Least Square (LS) ； Minimum Mean Square Error (MMSE)

參考文獻

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