DTMB系统的时频同步联合估计算法的研究

Study on the Joint Estimation Algorithm of Timing and Frequency Synchronization for DTMB System

针对中国地面数字电视广播传输标准,提出时频同步联合估计算法,该算法包括3个步骤:首先变步长扫频进行频偏粗估计,然后根据频偏粗估计值进行帧同步和帧序号估计,最后利用频偏粗估计值和帧同步估计出的帧头位置,将接收到的帧头前后165个数据相关进行频偏细估计,这样最终得到帧头位置、帧序号和频偏估计。理论分析和仿真结果表明,在多径信道下,该联合估计算法有较好的同步性能。

The joint estimation algorithm of timing and frequency synchronization is proposed to meet the Chinese DTFB standard. The algorithm includes three steps：After estimated the coarse frequency offset by frequency scan algorithm with adjustable steps, frame synchronization and frame number estimation was carried out according to the coarse frequency offset value, and then the fine frequency offset calculat was calculated based on the the sub-sequence correlation result by using the coarse frequency offset value and the frame header location; and eventually get frame header, frame number and frequency offset estimation value. The theory of the algorithm was given and the simulation results under muhi-path channels demostrate the better performance of the proposed algorithm .