无人机数据链系统中OFDM定时估计技术研究

Study on OFDM Timing Estimation Technique in UAV Data Link System

提出一种基于加权差分相关的OFDM定时估计方法,利用已知前导消除接收前导符号的调制信息,并通过加权差分相关与加窗修正得到具有脉冲特性的定时估计度量。通过对信号的相位信息进行相关处理,可以进一步得到具有低复杂度的定时估计方法。仿真结果表明,在多径衰落信道下,提出的OFDM定时估计方法具有较好的估计性能,适用于复杂通信环境下的无人机数据链系统。

A timing estimation method is proposed based on weighted differential correlations for OFDM systems. This method eliminates the received preamble symbol＇ s modulation information by the known preamble. Then, it achieves an impulsive timing metric through weighted differential correlations and windowing modification. Furthermore, the timing estimation methods with low complexity are obtained by processing the phase values of OFDM signals. Simulation results show that the proposed OFDM timing estimation methods perform well in multipath fading channel, which can be applied in Unmanned Aerial Vehicle （UAV） data link systems in complicated communication environment.