【摘要】 为了消除MIMO-OFDM移动水声通信系统中的多普勒效应,提出了一种训练序列结构及其相应的多普勒扩展估计方案.发射端在每一帧信号前插入2段相同的训练序列,接收端使用多个并行相关器对接收到的2段训练序列进行自相关运算,根据输出的最大自相关值所对应的相关器窗口长度即可进行多普勒扩展因子估计.仿真结果表明,与传统的以LFM信号为训练序列的估计方案相比,所提方案充分利用了MIMO技术提供的分集增益,进行更为精确的多普勒扩展因子估计,估计误差低于2×10^-3.更多还原

【Abstract】 To eliminate the Doppler effect in the multiple-input multiple-output orthogonal frequency division multiplexing（ MIMO-OFDM） mobile underwater acoustic communication system,a training sequence structure and the corresponding Doppler scale estimation scheme were proposed. The transmitter inserts two identical training sequences ahead of each signal frame,while the receiver uses several parallel correlators to calculate the autocorrelation of the two received training sequences.Then,the Doppler scale factor can be estimated according to the windowlength of the correlator with the maximum autocorrelation value. The simulation results showthat,compared with the traditional estimation scheme using the linear frequency modulation（ LFM） signal as the training sequence,the proposed scheme can estimate the Doppler scale factor more accurately by fully utilizing the diversity gains of the MIMO technique,and the estimation error is less than 2 × 10^-3.更多还原