Abstract: Chaotic sequence, with its good correlation performance, being sensitive to initial condition and hard to be decrypted, has been used as an ideal spread spectrum code in direct spread spectrum communication system. In order to take full advantages of the chaotic sequences ranging, based on the analysis of the basic principle of the pseudo code ranging and by using the digital matched filter to achieve the chaotic sequences acquisition, two chaotic spread spectrum ranging schemes were designed and their ranging processes, acquisition time and ranging accuracy were analyzed. The results show that taking the chaotic code as the spread spectrum code of ranging is feasible, with the strongpoint of high security, low interception, and it is also suitable for multi-target ranging, etc.

Key words: chaotic sequence, spread spectrum code, pseudo code ranging, capture time, ranging accuracy

摘要： 混沌序列以其相关性好、对初值敏感、保密性强等特性成为直接扩频通信系统中理想的扩频码。为充分发挥混沌序列测距的优点，在分析伪码测距的基本原理基础上，设计了两种混沌扩频测距的方案，利用数字匹配滤波器进行混沌码捕获的方法实现测距，分析了其测距的工作过程、捕获时间和测距精度。通过理论与仿真分析结果表明，利用混沌码作为扩频码实现测距是可行的，且具有高保密性、低截获和适合多目标测距等优点。

关键词: 混沌序列, 扩频码, 伪码测距, 捕获时间, 测距精度