基于训练序列的SC-FDE系统定时同步改进算法

Improved timing synchronization algorithm for SC-FDE system based on training sequence

由于Minn算法得到的定时同步度量函数会在不正确的定时同步点处产生多个差别较小的次峰且峰值形成缓慢,从而造成符号定位点模糊,定时同步存在偏差的问题。从SC-FDE系统同步技术着手,提出一种基于Minn算法的改进算法。该算法利用具有良好自相关特性的ZC(Zadoff-Chu)训练序列代替原有PN序列,且将重复的帧结构变更为中心对称的形式,并将训练序列进行多次相关以提高精度。通过对2种算法进行Matlab仿真论证,结果表明,所提的改进算法定时尺度非常尖锐,且在同等条件下有更低的均方差。

As the timing synchronization metric function obtained by the Minn algorithm produces multiple sub-peaks with little difference at the wrong timing synchronization points and the peak values form slowly,causing fuzzy symbol location points and timing synchronization errors,an improved algorithm based on Minn algorithm is proposed,proceeding from the SC-FDE synchronization technology. This algorithm takes advantage of the ZC(Zadoff-Chu)training sequence which has good self-correlation characteristic to take place of the original PN sequence. The repeated frame structure is changed to the central-symmetric form,and the training sequence is correlated many times to improve its precision. The Matlab simulation for the two algorithms was carried out. The results show that the improved algorithm has very shape timing metric peak and lower root mean square error(RMSE)in the same condition.