基于自适应最优抛物线核函数的Wigner-21/2维时频表示算法  

A Wigner-21/2 Time-Frequency Representation Algorithm Based on Adaptive Optimal Parabola Kernel

作　　者：刘义海[1] 张效民[1] 张炳骐[2] 

机构地区：[1]西北工业大学航海学院,西安710072 [2]美国纽约州立大学电子与计算机工程系,纽约11794

出　　处：《上海交通大学学报》2015年第10期1551-1557,共7页Journal of Shanghai Jiaotong University

摘　　要：针对低信噪比条件下非平稳、非线性和非高斯信号的时频特征分析,提出了一种基于自适应最优抛物线核函数的Wigner-212维时频表示算法.采用依赖于特定时频点的二维时频局部模糊函数替代传统Cohen类高阶时频分析中通用的全局时频模糊函数;利用自适应核处理技术获得局部模糊函数的最佳抛物线核函数,以最大限度地抑制交叉项的影响,提高算法的时频分辨率和信号自适应性;通过合成信号和水声信号的仿真实验进行时频分析,并与现有时频算法加以对比.结果表明,在低信噪比条件下,所提出算法对瞬态信号的检测优势明显,能够取得优良的时频特征解析效果.To obtain the time-frequency features of non-gaussian,non-linearity and non-stationary signals at a low SNR situation,a Wigner-212time-frequency representation based on adaptive optimal parabola kernel（Wigner-212AOPK-TFR）was proposed.First,a two-dimensional local ambiguity function（LAF）depending on specific time-frequency point was utilized instead of the commonly utilized global ambiguity function based on the whole time-frequency plane.Next,the optimal parabola kernel,which could greatly pass the auto-terms and cancel the cross-terms in the LAF,was obtained by using the adaptive optimizing technology,and was utilized to enhance the time frequency resolution and signal adaptability of the Wign-AOPK-TFR.Finally,the proposed method was tested by time-frequency analysis of synthetic and real-life signals.Simulation results confirm the effectiveness of the proposed method in low-SNR non-stationary signal analysis,compared with the traditional time-frequency method.

关 键 词：时频表示 非平稳信号处理 时频局部模糊函数 自适应抛物线核函数 

分 类 号：TN911[电子电信—通信与信息系统]