一种新的定时和频偏联合估计算法

A Novel Joint Estimation Algorithm of Timing and Carrier Frequency Offset

提出了一种新的正交频分复用(OFDM)系统定时和频率同步联合算法。该算法仅需要一个训练符号就可以完成定时和频偏估计,额外开销量小,定时和频率同步的实现均在时域进行,简化了同步实现的复杂度。由于使用自相关处理,定时同步对频率偏差具有较强的鲁棒性。与以往的定时同步算法相比,该算法避免了定时平台和多峰值的出现,即使在非常低的信噪比下,其定时测度都是一个尖脉冲。仿真结果表明,该算法能快速地实现定时和频率同步。

A novel joint estimation algorithm of timing and carrier frequency synchronization for orthogonal frequency division multiplexing （OFDM） systems is presented. Only one training symbol is used for symbol timing and carrier frequency offset estimation, the overhead is small. Timing synchronization and carrier frequency synchronization are achieved in time domain, thus the complexity of synchronization is reduced. As autocorrelation is used, timing estimation is robust against cartier frequency offset. Compared with the existing OFDM system timing synchronization algorithms, the presented algorithm avoids the phenomenon of plateau or multpeak in timing metric. Even for very low single-to-noise ratio（SNR）, a peak pulse can be present in timing metric while the presented algorithm is used. Simulations show that the algorithm can estimate the timing offset and frequeney offset quickly and exactly.