| Summary: | 碩士 === 國立中山大學 === 通訊工程研究所 === 95 === In this thesis, channel estimation technique in Multiple Input Multiple Output - Orthogonal Frequency Division Multiplexing (MIMO-OFDM) systems is investigated. Channel estimation plays an important role in the receiver performance of the MIMO-OFDM systems. In this thesis, the Space-Frequency Block Codes - Orthogonal Frequency Division Multiplexing (SFBC-OFDM) structure with the superimposed training scheme are adopted to increase bandwidth efficiency. In addition to using the first-order statistics of the received signal to reduce the interference induced by the unknown signals, the modified least square (MLS) estimator and the decision-feedback scheme are combined together to improve the channel estimation. In contrast to the conventional interference cancellation scheme for channel estimations adopting the decision feedback mechanism, the structure of the SFBC is utilized to decrease the interference. Furthermore, the effects of the decision-feedback scheme with erroneous decisions upon channel estimation are also examined. Analytical results show that the proposed method has better performance and computation complexity is not increased.
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