基于IEEE 802.11n无线局域网系统的符号同步

Symbol timing synchronization for IEEE 802.11n WLAN systems

IEEE 802.11n无线局域网标准为了避免不必要的波束成型采用了循环移位机制,该机制对符号同步造成障碍,使得符号同步产生所谓的假多径问题。针对这个问题,本文提出了一种采用移位叠加的本地训练序列互相关的同步方法。通过对IEEE 802.11n无线局域网系统进行建模仿真,对新提出的方法和前人所提出的方法进行比较。最终验证该同步方法具有实用性,能够大幅度的提升同步的精度,使得符号同步的定位误差控制在2个采样点之内。

IEEE 802.11n Wireless LAN standards use the cyclic shift diversity （CSD） scheme in order to avoid unnecessary beamforming, but the scheme makes barriers to the symbol timing synchronization, causes the pseudo muhipath problem in symbol timing synchronization. Aiming at this problem, this paper proposes a novel synchronization method using the local training sequence shift superposition correlation. Through the simulation of IEEE 802.11n Wireless LAN system,to compare the novel method to the previous method. Proving the verification of the synchronization method is practical finally, it can improve the synchronization accuracy greatly, makes the symbol synchronization error in the 2 sample points.