根据直扩原理，首先有随机数发生器产生一系列二进制信息数据（+1，-1），每个信息比特重复Lc次，Lc对应每个信息比特所包含的伪码片数，包含每一比特Lc次重复的序列与另一个随机数发生器产生的PN序列c(n)相乘。然后在该序列上叠加高斯白噪声和形式为i(n)=Acosw0n余弦干扰下次信号，切余弦干扰信号的振幅满足条件A<Lc。在解调器中进行与PN序列的互相关运算，并且将组成各信息比特的Lc个样本进行求和。加法器的输出送到判决器，将信号与门限值0进行比较，确定传送的数据为+1还是-1，计数器用来记录判决器的错判数目。-According to the principle, first some straight expansion random number generator produces a series of binary data (+ 1-1), each information bit repetitive Lc times, Lc for each information bit contains PN code piece count, embraces each bit Lc times repeated sequence and another random number generator produces PN sequence c (n) multiplication. Then in the sequence superimposed on gaussian white noise and forms as I (n) = Acosw0n cosine interference next time signal, cut cosine interfering signal amplitude satisfy conditions A < Lc. In the modem with the cross-correlation operation PN sequence, and the information will comprise the Lc a sample bits peace. The output of the adder judgment device, will signal to compare with threshold 0 data transmitted, determine for+ 1 or-1, counter is used to record the number victimised judgment.