基于系统一阶摄动解主频功率比的弱信号检测方法  

Weak Signal Detection Method Based on Dominative Frequency Power Ratio Derived from System's First-order Perturbation Solution

作　　者：孙文军[1] 芮国胜[1] 张洋[1] 陈强[1] 

机构地区：[1]海军航空工程学院电子信息工程系,烟台264001

出　　处：《电子与信息学报》2016年第1期160-167,共8页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(41476089)~~

摘　　要：针对现有混沌检测算法精度不高、状态响应滞后的问题,该文从混沌状态整体性、系统解频域特性等角度进行全面分析,提出一种基于摄动解主频功率比的弱信号检测方法,该算法不仅准确实现了临界状态的有效界定,提高了信号检测的可靠程度,而且揭示了系统各个状态之间的差别及物理含义。文中采用参数摄动法推导了Duffing-Van der pol振子的一阶摄动平衡解,证明了其为影响主频率分量的主要因素。在此基础上,采用经验模态分解方法对有效参量信息进行选择性重构,以最小均方误差约束准则下的比值系数重新定义了系统状态,得到系统主频功率比与策动力幅值之间的映射关系,并以此作为临界阈值确定的依据。实验结果表明,采用主频功率比准则的信号检测方法可靠性提高了约1个数量级,且算法的响应速度为传统分析方法的2倍以上。Traditional chaotic detection methods have many problems, such as low criterion accuracy and delay state response. To cope with these problems, a weak signal detection method based on dominative frequency power ratio derived from system＇s first-order perturbation solution is proposed in this paper. This algorithm is ascribable to the all-around analyses of chaotic state＇s global property and system solution＇s frequency-domain characteristics. It not only gives an effective and accurate critical threshold which could offer more reliable guarantee for signal detection, but also disclosures the differences between system states and the coherent physical meanings. The first-order perturbation equilibrium solution of Duffing-Van der pol oscillator is derived with parameter perturbation method, and it is proved that this solutionis is most significant to the dominative frequency. And then, the effective signal is selectively reconstructed through empirical mode decomposition, and system state is redefined with this ratio restrained under MMSE criterion. Finally the mapping relationship between power ratio of dominative frequencies and driving motivation amplitude is obtained and it is considered as determination criterion of critical threshold. Experimental results show that this algorithm could bring an promotion about one order of magnitude in system reliability, and the response speed is at least doubled compared with traditional methods.

关 键 词：信号处理 一阶摄动平衡 主频功率比 临界阈值 最小均方误差 

分 类 号：TN911.23[电子电信—通信与信息系统]