计算机工程与应用
計算機工程與應用
계산궤공정여응용
Computer Engineering and Applications
2015年
20期
16-21
,共6页
时-频分析%离散S变换%时域算法%频域算法%周期性
時-頻分析%離散S變換%時域算法%頻域算法%週期性
시-빈분석%리산S변환%시역산법%빈역산법%주기성
time-frequency analysis%discrete S transform%time-domain algorithm%frequency-domain algorithm%periodicity
在信号处理领域，S变换具有良好的时频结合特性，应用广泛。在实际系统中，S变换通过离散数值方法实现，有频域和时域两种形式，文献中多使用频域形式。在用S变换对一些信号作时-频分析时，频域和时域两种实现形式得到的时-频谱图有明显的差异，但没有文献对此问题进行相关讨论。离散S变换的频域算法使用快速Fourier变换（FFT）和其逆变换（IFFT）实现，但由于Fourier变换蕴含周期特性，一些信号的S变换时-频谱图在始末两端会出现虚假频率信息，干扰信号的时-频分析结果。在研究S变换理论的基础上，给出离散S变换的时域实现。离散S变换的时域算法克服了频域算法的缺点，能更准确反映信号的时-频分布情况。通过对比实验，验证了时域算法的有效性。将S变换的离散时域算法用于地震数据拓频处理，结果显示方法能有效增强信号分辨率。
在信號處理領域，S變換具有良好的時頻結閤特性，應用廣汎。在實際繫統中，S變換通過離散數值方法實現，有頻域和時域兩種形式，文獻中多使用頻域形式。在用S變換對一些信號作時-頻分析時，頻域和時域兩種實現形式得到的時-頻譜圖有明顯的差異，但沒有文獻對此問題進行相關討論。離散S變換的頻域算法使用快速Fourier變換（FFT）和其逆變換（IFFT）實現，但由于Fourier變換蘊含週期特性，一些信號的S變換時-頻譜圖在始末兩耑會齣現虛假頻率信息，榦擾信號的時-頻分析結果。在研究S變換理論的基礎上，給齣離散S變換的時域實現。離散S變換的時域算法剋服瞭頻域算法的缺點，能更準確反映信號的時-頻分佈情況。通過對比實驗，驗證瞭時域算法的有效性。將S變換的離散時域算法用于地震數據拓頻處理，結果顯示方法能有效增彊信號分辨率。
재신호처리영역，S변환구유량호적시빈결합특성，응용엄범。재실제계통중，S변환통과리산수치방법실현，유빈역화시역량충형식，문헌중다사용빈역형식。재용S변환대일사신호작시-빈분석시，빈역화시역량충실현형식득도적시-빈보도유명현적차이，단몰유문헌대차문제진행상관토론。리산S변환적빈역산법사용쾌속Fourier변환（FFT）화기역변환（IFFT）실현，단유우Fourier변환온함주기특성，일사신호적S변환시-빈보도재시말량단회출현허가빈솔신식，간우신호적시-빈분석결과。재연구S변환이론적기출상，급출리산S변환적시역실현。리산S변환적시역산법극복료빈역산법적결점，능경준학반영신호적시-빈분포정황。통과대비실험，험증료시역산법적유효성。장S변환적리산시역산법용우지진수거탁빈처리，결과현시방법능유효증강신호분변솔。
With excellent time-frequency combination, S transform has been extensively used in the field of signal pro-cessing. In physical system, S transform can be finished with discrete numerical calculation, providing a correct basis for analyzing and solving problems. The discrete S transform can be implemented in two ways which are frequency-domain and time-domain and the former being used widely. There are some obvious differences on signal spectrograms by differ-ent algorithms, but the related references about it cannot be found. The frequency-domain algorithm of discrete S trans-form is usually implemented by FFT and IFFT. Due to the inherent periodicity of Fourier transform, the ends of signal spectrogram generated by frequency-domain algorithm have false frequency information, interfering signal time-frequency analysis. Based on the study of basic principles of S transform, this paper proposes a time-domain algorithm of discrete S transform, which overcomes the shortages of the frequency-domain algorithm and can map signal time-frequency distribu-tion more accurately. The paper validates the algorithm of time-domain by introducing comparative tests, and gives using recommendations. The frequency-broadening processing of the algorithm is used real seismic data, and the result indicates that this method can availably improve seismic signal resolution both in time and frequency domain.
