频率选择信道下STBC-OFDM信号盲识别

发布时间：2019-05-17 05:18

【摘要】：针对多输入单输出(multiple input single output,MISO)通信系统的空时分组编码-正交频分复用(space-time block codes-orthogonal frequency-division multiplexing,STBC-OFDM)信号盲识别问题,提出了一种基于四阶统计量的盲识别算法。该方法首先对MISO通信系统的STBC-OFDM信号进行建模;然后利用STBC-OFDM信号编码矩阵的相关性,构造了不同时延向量下接收信号OFDM块的时延四阶矩作为特征函数;最后通过时延四阶矩理论值与实验值的最小欧式距离盲识别发射端STBC-OFDM信号的编码方式。该方法不需要信道系数、噪声信息和调制信息等先验信息,适合非合作通信场合。仿真结果表明,所提出的算法即使在低信噪比(SNR=0dB)下识别效果接近100%,且对载波频偏、时间同步偏差和多普勒频移不敏感,实用性较强。
[Abstract]:In order to solve the problem of blind recognition of space-time block coding orthogonal frequency division multiplex (space-time block codes-orthogonal frequency-division multiplexing,STBC-OFDM) signals in multi-input single-output (multiple input single output,MISO) communication systems, A blind recognition algorithm based on fourth-order statistics is proposed. Firstly, the STBC-OFDM signal of MISO communication system is modeled, and then the fourth moment of delay of OFDM block of received signal under different delay vectors is constructed as characteristic function by using the correlation of STBC-OFDM signal coding matrix. Finally, the coding method of STBC-OFDM signal at the transmitter is blindly identified by the minimum Euclidean distance between the theoretical value of the fourth moment and the experimental value. This method does not need prior information such as channel coefficient, noise information and modulation information, and is suitable for non-cooperative communication. The simulation results show that the proposed algorithm is close to 100% even at low signal-to-noise ratio (SNR=0dB), and is insensitive to carrier frequency offset, time synchronization deviation and Doppler frequency shift, and has strong practicability.
【作者单位】：海军航空工程学院信息融合所;海军航空工程学院电子信息工程系;
【基金】：国家自然科学基金(91538201) 泰山学者专项经费(ts201511020)资助课题
【分类号】：TN914

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