Abstract: Concerning the problem of demodulating the weak Binary Phase Shift Keying (BPSK) signal, the demodulation method based on chaotic system was researched. The basic principle of the chaotic system weak signal detection was introduced. By combining with the phase condition of the phase change happening and the modulation method of BPSK signal, the methods and steps of using Duffing system to demodulate the BPSK signal in strong noisy background were given. And a new method was presented for power spectrum entropy to judge the complexity of the different system state. Based on theoretical analysis, the simulation model based on Matlab/Simulink was built. The digital simulation results show that the performance of demodulating the weak BPSK signal using chaotic oscillator and power spectrum entropy is better than that of traditional coherent demodulation method.

Key words: Duffing oscillator, BPSK signal, power spectrum entropy, demodulation, Simulink model

摘要： 针对微弱二进制相移键控(BPSK)信号的解调问题,对基于混沌系统的解调方法进行了研究。介绍了混沌系统微弱信号检测的原理,结合混沌系统产生相变的相位条件和BPSK信号的调制方式,给出了利用Duffing系统进行强噪声背景中BPSK信号解调的方法和步骤,并提出了利用功率谱熵对系统不同状态复杂度进行判别的新方法。在理论分析的基础上,建立了Matlab/Simulink仿真模型。仿真结果表明,利用混沌振子和功率谱熵解调微弱BPSK信号的性能优于传统的相干解调方法。

关键词: Duffing振子, BPSK信号, 功率谱熵, 解调, Simulink模型