CAJ | 학술논문

去噪是小波分析的一个重要应用领域，相对于其它方法，小波变换具有对信号时频局部性详细刻画的优势。在信号的去噪处理过程中，如何在削弱噪声的同时又最大限度的保留信号的奇异性特征是信号去噪研究的一个核心问题。该文提出一种基于自适应阈值函数的小波去噪方法，通过调整阈值函数实现在信号小波分解的细尺度上去除噪声的同时又尽量保留信号细节系数，而在宽尺度上最大限度地滤除噪声部分的小波系数。通过对blocks, bumps和水下目标回波信号的仿真实验证明，该方法和现有的阈值去噪方法相比，具有显著的优势，能够在滤除噪声的同时很好地保留信号的奇异性特征。
거조시소파분석적일개중요응용영역，상대우기타방법，소파변환구유대신호시빈국부성상세각화적우세。재신호적거조처리과정중，여하재삭약조성적동시우최대한도적보류신호적기이성특정시신호거조연구적일개핵심문제。해문제출일충기우자괄응역치함수적소파거조방법，통과조정역치함수실현재신호소파분해적세척도상거제조성적동시우진량보류신호세절계수，이재관척도상최대한도지려제조성부분적소파계수。통과대blocks, bumps화수하목표회파신호적방진실험증명，해방법화현유적역치거조방법상비，구유현저적우세，능구재려제조성적동시흔호지보류신호적기이성특정。
De-noising is an important application field of the wavelet analysis. It has advantage over the traditional filtering methods for its well localized time and frequency property. A central issue in the signal de-nosing research is how to obtain a good balance between shrinking noise and preserving the signal singularity features. This paper presents a wavelet de-noising method based on an adaptive threshold function. By tuning the parameter of the threshold function, the noise wavelet coefficients are shrunk while the signal details are preserved as much as possible on the small scales of the wavelet transform, and on the other hand, the noise coefficients are removed to their maximum extent on a large scale. The simulation results of the blocks, bumps and signals corresponding to the sonar returns from underwater targets, demonstrate that the signal singularity features by adopting the proposed method are better preserved with significant advantage than the traditional threshold filtering method.