进行帧同步的目的是为了得到帧头的位置，以分辨以符号周期为单位的延时。本质上，目的是寻找一个接收端已知的已发送信号的参考信号（即训练序列）以进行后续的如信道估计和信道均衡的操作。有关帧同步的理论有很多，这里只实现一种基于训练序列的相关性质的方法。(The purpose of frame synchronization is to get the position of the frame header to resolve the delay in symbol periods. In essence, the purpose is to find a reference signal (ie a training sequence) of the transmitted signal known to the receiving end for subsequent operations such as channel estimation and channel equalization. There are many theories about frame synchronization, here only one method based on the nature of training sequences is implemented.)