基于小波域可导阈值函数与自适应阈值的脉冲星信号消噪  

A differentiable thresholding function and an adaptive threshold selection technique for pulsar signal denoising

作　　者：高国荣[1] 刘艳萍[1] 潘琼[1] 

机构地区：[1]西北农林科技大学理学院,杨凌712100

出　　处：《物理学报》2012年第13期549-553,共5页Acta Physica Sinica

摘　　要：脉冲星辐射信号具有极低的信噪比,传统降噪方法难以在抑制噪声的同时保留其细节信息.为此,提出了一种小波域脉冲星信号消噪方法.在小波域,利用一种可导的阈值函数和一种自适应阈值选取方法,对含噪脉冲星信号进行小波域阈值去噪处理,并利用信噪比(SNR)、均方根误差(RMSE)、峰值相对误差(REPV)以及峰位误差(EPP)四项指标来对去噪效果进行评价.实验结果表明,与软阈值与硬阈值法相比,该方法能在有效去除含噪脉冲星信号中的噪声、显著提高其信噪比的同时,更有效地保留原始信号中的有用信息,同时可以获得更小的均方根误差、脉冲峰值相对误差与峰位误差.Because of the extremely low signal-to-noise ratio of pulsar signals, it is difficult to suppress noise while preserving details by the traditional denoise methods. Therefore, a wavelet domain pulsar signal denoising method based on a differentiable thresholding function and an adaptive threshold selection technique is presented. The signal-to-noise ratio（SNR）, the root mean square error（RMSE）, the relative error of the peak value （REPV） and the error of the peak position （EPP） are used to evaluate the performance of the proposed denoising method. Experimental results show that the proposed method can remove the pulsar signal noise and keep the useful information effectively. At the same time, it can achieve a higher PSNR, a lower RMSE, a lower REPV and a lower EPP than the soft thresholding and hard thresholding methods.

关 键 词：小波 脉冲星信号 自适应阈值 消噪 

分 类 号：TN911.4[电子电信—通信与信息系统]