基于双耦合混沌振子的未知频率弱信号检测

Detection of the Weak Signal with Unknown Frequency Based on the Coupled Chaos Oscillator

针对微弱信号检测的难点问题,提出了一种应用于未知频率微弱信号的分段测频检测方法.利用双耦合Duffing系统相轨迹状态的跃迁对于输入微弱信号的敏感特性实现了对淹没在强噪声中的微弱信号的检测,同时利用分段测频方法实现了对微弱信号的频率测量,有效地解决了单Duffing振子的微弱信号检测方法易受噪声影响产生误判的问题,突破了现有微弱信号混沌振子检测方法只能进行已知频率信号检测的局限性.仿真实验结果证明该方法确实能够较为准确地检测出输入微弱周期信号的频率,使微弱信号检测技术得到进一步完善.

A sub-frequency measurement method for weak signals with unknown frequency was presented. Due to the sensitivity of the state transitions of the phase trajectories of the coupled Duffing system to the weak signal input, the detection for a weak signal submerged in strong noises was implemented to solve the difficult problems of weak signal detection. Based on the proposed method, the problem on misjudgment of weak signal detection method based on single Duffing oscillator under the influence of noise effectively was solved. And the limitation had been broken that the existing detection methods of weak signal based on chaotic oscillator could only detect the weak signal with known frequency. Simulation results showed that the method could indeed detect the frequency of weak periodic input signal more accurately, resulting in improvement of the weak signal detection techniques.