【作者】 冯晓峰； 裴继红； 谢维信；

【Author】 Feng Xiao-feng Pei Ji-hong Xie Wei-xin (Intelligent Information Institute,Shenzhen University,Shenzhen 518060,China)

【机构】 深圳大学智能信息研究所；

【摘要】 利用小波变换对信号压缩时,小波基的选取十分重要。利用不同的小波基对信号进行压缩,将得到不同的压缩效果。另外,压缩方法的好坏需要利用不同的评估方法进行评价,因此压缩方法的评估问题对于压缩方法的研究也十分重要。在THz信号的压缩方法研究中,这两个问题还没有得到很好的解决。本文中,首先基于THz信号的特点及其压缩要求引入了四种评估方法,然后分别在频域和吸收谱域上利用这四种评估方法对小波压缩结果进行评估,根据两个域上的不同评估结果可以验证,在吸收谱域上对THz压缩信号进行评估是必要的和适用的。最后还根据评估结果选出了较优小波基和较劣小波基,利用选出的小波基对THz信号进行2层小波压缩,对比压缩后信号的吸收谱与原信号吸收谱的一致性和相似性,从而验证了前面所给出的四个评估方法的有效性。更多还原

【Abstract】 The selection of wavelet basis is very important in wavelet transform for signal compression.Different wavelet basis will lead to different effects.On the other side/moreover/,different evaluation methods are needed to appraise the performance of compression methods.Then,the evaluation method for compression is also very important.However,in the study of THz signal compression the two issues have had not been well resolved.In this paper,four evaluation methods based on the characteristics of THz signal and compression requirements has been introduced.Then,the effect of compression of THz signal in frequency domain and absorption spectrum domain are estimated by the four evaluation methods.According to these results,we can verify that it is essential and suitable to evaluate the compression results in absorption spectrum domain for THz signal compression.By comparing these results,we can find the good and poor wavelet basis.And we get different compressed signals with the selected wavelet basis by 2-layer wavelet compression of THz signal.By observing the consistency and similarity of absorption spectrum between compressed signal and original signal,we can verify the effectiveness of the four evaluation methods we present.更多还原