【摘要】 混沌直扩信号是由普通混沌信号直接调制信息信号得到的一类扩频通信信号,它兼有混沌信号和直扩信号容量大、低截获等特点.该文针对复杂环境下非合作混沌直扩信号检测的问题,考虑到多径传输及噪声条件下混沌直扩信号混沌特性被明显削弱,在考察直接检测方法的基础上提出一种基于ICA的信号盲分离和混沌特性检测相结合的检测方法.首先将接收到的混合信号分离成各单路信号,再检测各路信号的混沌特性.理论分析和仿真实验表明,分离后混沌直扩信号的纯净度明显提高,基本上不再受噪声等的影响,在输入信噪比-40dB条件下仍可有效检测出混沌直扩信号.更多还原

【Abstract】 Chaotic DS signal is a kind of spread spectrum signal generated by directly modulating information signal with a chaotic signal.Communications using chaotic DS signals instead of conventional direct sequence spread spectrum signals have many advantages such as larger capacity and low probability of intercept. However,detection of chaotic DS signals is difficult.We propose a method to detect chaotic DS signals by calculating the largest Lyapunov exponent of the time series after being separated from the received signals using an ICA blind signals separation algorithm.Simulation results show feasibility of this method under Gaussian noise and multi-path channel interferences.更多还原