说明：  CRC校验码的基本思想是利用线性编码理论， 在发送端根据要传送的k位二进制码序列，以一定的规则产生一个校验用的监督码（既CRC码）r位，并附在信息后边，构成一个新的二进制码序列数共(k+r)位，最后发送出去。在接收端，则根据信息码和CRC码之间所遵循的规则进行检验，以确定传送中是否出错。
(The basic idea of CRC check code is to use linear coding theory to generate a supervisory code (CRC code) r bit for check according to the sequence of k-bit binary codes to be transmitted at the sender, and attach it to the information to form a new binary code sequence number (k+r) bits, and send it out finally. At the receiving end, the rules between the information code and the CRC code are checked to determine whether there is an error in the transmission.)