国标地面数字电视接收机定时同步算法的改进

Improved Timing Synchronization Algorithm for Receivers of Chinese National Standard of DTV Terrestrial Broadcasting

提出了一种改进的国标数字电视地面广播接收机定时同步算法。该算法对基于PN序列相关的鉴相算法进行了改进,即对相关值进行预滤波,以检测出定时偏差,并采用全数字锁定环技术实现整个算法。软件仿真表明:在相同的信道环境和相近的环路收敛性能条件下,改进后的算法可以工作在2倍符号速率上,有效地降低了算法的复杂度。同时,通过对预滤波器的设计,可灵活地调节S曲线的形状,以调整算法捕获定时偏差的范围。

In this paper, an improved timing synchronization algorithm for receivers of the Chinese national standard of Digital Television Terrestrial Broadcasting （DTTB）. The proposed algorithm is proposed improves the traditional timing methods based on PN correlation. The correlation output is pre-fihered to detect the timing errors. And the timing loop is implemented by all digital locking loop. The results show that the improved algorithm has similar loop performance under the same channels. However, the improved algorithm only needs 2 samples per symbol, which effectively reduces the complexity of the timing loops. Moreover, in the improved scheme, the S-curve can be adjusted as well by changing the design of the pre-filter, which makes the timing error capture range adjustable.