随机共振应用于窄带PSK信号处理的研究

Application of Stochastic Resonance in Narrow-band PSK Signal Processing

非线性随机共振系统能够有效利用噪声能量增强微弱周期信号,可用于强噪声背景下的微弱通信信号检测。本文提出基于人工鱼群算法的自适应随机共振方法处理相移键控(PSK)信号,分别从算法应用于参数估计、应用于降低检测信噪比门限、应用于提高带内信噪比三个角度分析算法对PSK信号检测性能带来的提升,阐述了采样率在窄带PSK信号参数估计的随机共振中的作用。理论分析和仿真结果表明,对比传统谱线法其能够明显提升PSK信号参数估计性能,将参数估计信噪比门限降低3~6 d B,并具有良好的收敛性能。此外,验证随机共振直接处理窄带周期信号没有实际提升效果。

The phenomenon that noise enhancing weak period signals in Non-linear stochastic resonance systems can be uti- lized detecting weak communication signals in strong noise background. A new method of adaptive stochastic resonance based on artificial-fish swarm optimization is proposed to handle narrow-band PSK signals in this article. The promotions in PSK signal processing are introduced in three aspects： Application in narrow-band PSK signals parameter estimation, opti- mizing the performance of the SNR threshold to detect narrow-band PSK signals and improvement in-band signal to noise ra- tio （SNR） of PSK signals. The influence of sampling rate in stochastic resonance of the narrow-band PSK signals is ex- posed in this article. The result of theoretical analysis and simulation experiments show this method of adaptive stochastic resonance based on artificial-fish swarm optimization handling PSK signals can give evident promotion in the performance of parameter estimation and lower the detecting SNR threshold by 3 ~ 6 dB on contrast to traditional methods based on spectral lines. Besides, it has good convergence performance. Meanwhile, stochastic resonance is verified useless in detecting nar- row-band PSK signals directly.