cx

说明：  利用Matlab编写求取4级移位寄存器的M序列 设初始序列为:1 1 1 1 通过一个四级的移位寄存器,其中在第三级有负反馈(一个模二加法),即将序列的第三位和第四位相加(如序列1 1 1 1经移位寄存器第一次移位后为0 1 1 1)的值再赋到第一位. 序列的周期为16.(The use of Matlab to prepare to strike four of the M shift register sequence based initial sequence as follows: 1 1 1 1 4 through a shift register, which in the third grade there is negative feedback (one-mode two adder), the upcoming series third and fourth combined (such as the sequence 1 1 1 1 by the shift register after the first shift for the 0 1 1 1) the value given to the first again. The cycle sequence was 16.)