高速移动环境下基于正交角域子空间投影的时频同步算法研究

Orthogonal Angle Domain Subspace Projection Based Time-Frequency Synchronization Algorithm for High-speed Mobile Environment

在高速移动环境下,无线信道显现出较强的时变特性.由于各个到达径的多普勒频移不一致所导致的多普勒扩展,使得系统时频同步算法性能急剧下降.针对此问题,该文提出了一种基于正交角域子空间投影的时频同步算法.该算法利用多天线系统提供的角域分辨力,将多普勒扩展简化为各个正交角域子空间上的多普勒频移,从而提高时频同步算法的性能.仿真结果表明,在高速移动环境下。

In high-speed mobile environment,wireless channel shows serious time-varying characteristic. The Doppler spread caused by different Doppler frequency offset of each arrived multi-path signal worsens the performance of time-frequency synchro- nization algorithm. In this paper, a novel orthogonal angle domain subspace projection based time-frequency synchronization algo- rithm is proposed. In this algorithm, the angle resolution from multiple antennas system is utilized to simplify the Doppler spread as Doppler frequency offset on each orthogonal angle domain subspace, which can improve the performance of time-frequency synchro- nization algorithm. Simulation results show that the proposed algorithm suppress the effect caused by time-varying wireless channel and achieve better system performance.