Abstract: In this paper，an improved method about the process of the original chaotic sequence quantify is proposed which not only uses the method of mid multi-bit quantifying but also uses the technology of truncation to quantify.This new method reduces the number of iteration and also reduces the process of choosing and judging initial value.It uses FIPS PUB 140-2，an internationally accepted rule，to examine and simulate the sequence randomly.The result shows that the sequence has a good quality.Also，SystemView is used to establish direct spread spectrum model to verify the feasibility as a spreading code.

Key words: chaotic spreading sequences, quantitative method, randomness, spread spectrum communication system

摘要： 对原有的混沌序列数字量化过程提出一种改进的方法，该方法在运用中间多比特量化法的同时，采用截短技术对实值混沌序列进行量化，减少了序列的迭代次数与大量的初始值选择判决过程；采用国际上公认的FIPS PUB 140-2标准来对该序列进行随机特性检测、仿真，结果表明此序列具有良好的扩频特性；利用SystemView软件建立直接扩频通信模型加以仿真，验证其作为扩频码的可行性。

关键词: 混沌序列, 量化, 随机性, 扩频通信系统