对多人多出-正交频分复用(MIMO—OFDM)系统的频率同步问题进行研究,提出基于自适应训练序列的MIMO—OFDM系统的频率同步算法.所提出的训练序列利用接收端的信道状态信息(CSI)进行设计,并利用此训练序列对Schenk的载波频编(CFO)估计器进行改进,进一步提高了衰落信道下CFO估计的准确性.仿真结果表明,本算法能降低信道噪声的干扰,提高时变信道下CFO估计精度.
Joint design of the carrier frequency offset (CFO) estimator and adaptive training sequence for multi-input multi-output orthogonal frequency division multiplexing (MIMO-OFDM) system is investigated. With adaptive training sequence, which is optimized according to channel state information (CSI) available at the transmitter, proposed CFO estimator can update Sehenk's estimator and then reduce the effect of channel noise and further increase the accuracy of CFO estimation in fading channels.