基于联合去噪和频率调制的微弱信号检测  

Weak signal detection based on united denoising and frequency modulation

作　　者：张刚[1] 王颖[1] 王源[1] 

机构地区：[1]重庆邮电大学信号与信息处理重庆市重点实验室,重庆400065

出　　处：《系统工程与电子技术》2014年第10期1918-1923,共6页Systems Engineering and Electronics

基　　金：国家自然科学基金(61071196;61102131;61371164);教育部新世纪优秀人才支持计划项目(NCET-10-0927);信号与信息处理重庆市市级重点实验室建设项目(CSTC2009CA2003);重庆市杰出青年基金(CSTC2011jjjq40002);重庆市自然科学基金(CSTC2012JJA40008);重庆市教育委员会科研项目(KJ120525;KJ130524)资助课题

摘　　要：针对强噪声背景中弱信号检测问题,在传统检测方法基础上,提出了基于联合去噪和频率调制的微弱信号检测方法。搭建自相关和小波阈值变换联合去噪系统,极大程度抑制了噪声对检测结果的不利影响。利用频率可调标准信号调制待测信号频率,使得被测信号与检测系统策动力信号的频率差满足检测条件,打破了利用Duffing振子检测系统只能检测与系统策动力频率相近信号的限制。双振子差分进行混沌特性判别的方法更具直观性,抗噪性能好,测量相对误差被控制在5%以内;且系统具有很高的抗干扰性,检测最低信噪比可达-41dB。仿真结果证明了该方法的可行性和有效性。For the detection of weak signals in strong noise background, a novel method with united denois- ing and frequency modulation is proposed based on the conventional detection method. The joint denoising sys- tem combines autocorrelation and wavelet threshold transformation, so the negative impact from the noise is avoided greatly in the detection result. Using standard signals with adjustable frequency to modulate the meas ured signal frequency, thus the frequency difference of the standard signals and the measured signals meets the testing conditions. It breaks the restrictions of the Dulling oscillator, which can only detect signals with the frequency similar to the system driving force. The two-oscillator-difference method is more intuitive, with good anti-noise performance ability, and the relative error is controlled under 5%. The system has a strong anti-interference ability, and the minimum signal-to-noise ratio can reach -41 dB. The feasibility and validity of this method are proved by the simulation results.

关 键 词：DUFFING振子 频率调制 联合去噪 差分 

分 类 号：TM77[电气工程—电力系统及自动化]