此模块的基本功能是将待调信号与 M序列的每一位进行异或，到达扩频的目的。其中设计了一个5级的移位寄存器用于产生M序列。-The basic function of this module is the signal to be modulated with the M sequence of each XOR reach spreading purposes. Which designed a five shift register used to generate M sequences.