中文说明：此为频偏校正程序，通过TD_GG算法得到的频偏值还存在几赫兹的残余频偏，这里，我们可以通过反馈算法进行校正，以得到更加精确的频偏值。
English Description：
This is the frequency offset correction procedure, through TD_ There is a few hertz residual frequency offset in the frequency offset value obtained by GG algorithm. Here, we can correct it by feedback algorithm to get more accurate frequency offset value.