利用间歇混沌检测含噪未知频率信号的研究

Study on Using Intermittent Chaos to Detect Unknown Frequency Signal in Noise

研究发现被测信号频率和干扰噪声变化都会引起间歇混沌间隔的变化,通过仿真实验分析了被测信号频率和干扰噪声对间歇混沌特征影响的相互关联关系,从理论上分析了被测信号频率和相角变化对间歇混沌特征的影响,提出了一种利用间歇混沌特征变化测量含噪未知频率信号的方法,设计了有噪声和无噪声两种环境中对声波信号频率的检测实验。实验结果显示与Duffing混沌系统相比,利用Liu-cos混沌系统间歇混沌检测含噪未知频率信号的效果更好。

It is found that changes both of the frequency of measured signal and interference noise could cause the change of interval of intermittent chaos.The correlation between the frequency of the measured signal and the interference noise on the intermittent chaotic characteristics is analyzed through simulation experiments.The effects on the intermittent chaotic characteristics by the frequency and the phase angle of the measured signal are analyzed theoretically.A method for measuring the signals of unknown frequency in noisy environment by using intermittent chaotic characteristic changes is proposed.Experiments are designed to detect the frequency of acoustic signals in both noisy and noiseless environments.The experiments show that the detection of the signals of unknown frequency by intermittent chaos in noise by the Liu-cos chaotic system is better than that by Duffing chaotic system.