臺灣大學: 電信工程學研究所馮世邁周文揚Chou, Wen-YangWen-YangChou2013-03-272018-07-052013-03-272018-07-052012http://ntur.lib.ntu.edu.tw//handle/246246/252725無The well known advantages of orthogonal frequency division multiplexing (OFDM) in combating inter symbol interference (ISI) and frequency selective fading channels have led wireless relay networks to use OFDM for data transmission. However,it is well known that OFDM systems are sensitive to carrier frequency o set(CFO). The performance of these wireless relay networks degrades signi cantly when there is CFO. In this thesis, we study CFO estimation for a simple Space-Time OFDM scheme for relay networks. First, We derive an explicit expression of the correlation of the received signals at destination node. Based on this expression, we propose a simple preamble design for CFO estimation. The proposed preamble enables us to jointly estimate the relay CFO and destination CFO at the destination. In other words, the relay nodes do not need to do the complicated computation of CFO estimation. Moreover, both ESPRIT and MUSIC algorithms are derived. As all the matrices involved in the computation are small (3 3), the complexity of the proposed method is low complexity. Moreover numerical simulation shows that the proposed method has good performance and it compares favorably with existing methods.140 bytestext/htmlen-US載波頻率偏移正交分頻多工中繼網路時空編碼OFDMCFOrelaySTBCthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/252725/1/index.html