基于Duffing振子的2FSK信号检测方法研究

摘要

针对在强噪声环境中传输的应答器上行链路2FSK信号的检测问题,本文基于混沌系统对初始条件敏感及对噪声免疫的特性,利用Duffing振子检测应答器2FSK信号.结合混沌系统产生相变的条件和2FSK信号的调制方式,给出利用Duffing振子检测微弱2FSK信号的方法和步骤,并利用功率谱熵对系统在策动力作用下所处的不同状态进行判别.在理论分析的基础上,利用Matlab/Simulink建立仿真模型.仿真结果表明,利用Duffng振子检测2FSK信号,及以功率谱熵为判据的方法是可行的,并且其性能优于传统的相干检测法.该方法具有较高的检测精度和很好的抗噪声性能.%Concerning the problem of up-link Binary Frequency Shift Keying (2FSK) signal detection in strong noises,utilizing the chaotic system for its sensitivity to initial conditions and immunity to noises,the paper used the Duffing oscillator to detect the 2FSK signals.By combining with the phase change conditions of the chaotic system and the modulation mode of 2FSK signals,the methods and steps of using the Duffing oscillator to detect weak 2FSK signals were given.The power spectrum entropy was used to judge different states of the system under the action of driving forces.On the basis of theoretical analysis,the simulation model was built with Matlab/Simulink.The simulation results show that the methods to detect 2FSK signals with the chaotic oscillator and to make judgement with the power spectrum entropy as the criteria are feasible,which is proved superior to the traditional coherent detection method.The proposed method is characterized by high detection precision and good anti-noise performance.