α稳定分布噪声中基于最优核时频分析的跳频信号参数估计  

Parameter estimation of FH signals based on optimal kernel time-frequency analysis inαstable distribution noise

作　　者：金艳[1] 彭营[1] 姬红兵[1] 

机构地区：[1]西安电子科技大学电子工程学院,陕西西安710071

出　　处：《系统工程与电子技术》2015年第5期985-991,共7页Systems Engineering and Electronics

基　　金：国家自然科学基金(61201286);中央高校基本科研业务费专项资金(K5051202013);陕西省自然科学基金(2014JM8304)资助课题

摘　　要：针对传统非线性时频分析方法在跳频(frequency hopping,FH)信号参数估计时,会出现严重的交叉项和参数估计精度降低等问题,引入径向高斯核(radially Gaussian kernel,RGK)时频分析方法,该方法根据FH信号的不同自适应选择最优核函数,从而有效抑制交叉项。RGK时频分析方法可在高斯噪声环境下估计FH信号的参数,但在脉冲性较强的α稳定分布噪声中,该方法性能退化甚至失效。对此,结合最大似然估计理论,提出了一种α稳定分布噪声环境下的加权最大似然广义柯西(weighted maximum-likelihood generalized Cauchy,WMGC)滤波的新方法。采用基于WMGC滤波器的RGK时频分析方法(WMGC-RGK方法,即WR方法),对该噪声中的跳频信号进行参数估计。仿真结果表明,与基于分数低阶及Myriad的时频分析方法相比,WR方法在α稳定分布噪声中具有良好的鲁棒性和优良的跳频信号参数估计性能。In view of the problem that conventional non-linear time-frequency analysis methods in frequency hopping（FH） signals parameter estimation suffer from the effect of serious cross-components, a radially Gaussi- an kernel（RGK）time-frequency analysis method is introduced. To suppress the cross-components, it selects the adaptive optimal kernel depending on a variety of signals. The RGK time-frequency analysis method can esti- mate FH signals parameters in Gaussian noise, but its performance in heavy-tailed impulsive noise environment falls into severe degradation. Combined with the maximum likelihood estimation theory, a weighted maximum- likelihood generalized Cauchy（WMGC）method for the case of a stable distribution noise is proposed. The pa- rameters of noisy FH signals can be estimated by the RGK time-frequency analysis method based on the WMGC filter（WMGC-RGK method, simply WR method）. Simulation results show that compared with the fractional lower order statistics as well as the Myriad filter based time frequency analysis methods, the proposed method has better performance on the FH signals parameter estimation and it is robust to the α stable distribution noise.

关 键 词：跳频信号 交叉项 径向高斯核时频分析方法 参数估计 Α稳定分布噪声 加权最大似然广义柯西滤波 

分 类 号：TN911.7[电子电信—通信与信息系统]