SVD-Based Technique for Interference Cancellation and Noise Reduction in NMR Measurement of Time-Dependent Magnetic Fields.
SVD-Based Technique for Interference Cancellation and Noise Reduction in NMR Measurement of Time-Dependent Magnetic Fields.
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基于 SVD 的瞬态磁场 NMR 测量中的干扰消除和降噪技术
DOI：
10.3390/s16030323
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发表时间：
2016-03-04
期刊：
影响因子：
--
通讯作者：
Zhang H
中科院分区：
文献类型：
--
作者：
Chen W;Ma H;Yu D;Zhang H
介绍了一种测量含时磁场的核磁共振实验。为了提高核磁共振数据的信干噪比，提出了一种基于奇异值分解的干扰抵消降噪方法。该方法根据射频干扰数据与参考数据的相关性，识别出射频干扰信号对应的奇异值，并通过将奇异值置零来抑制射频干扰和噪声。通过对实测核磁共振数据的处理，验证了算法的有效性。实验结果表明，该方法对射频干扰和随机噪声有明显的抑制作用，能较好地保留FID信号。目前，所提出的基于SVD的ICNR技术的主要限制是用于干扰消除的阈值需要手动选择。最后，通过对处理后的实验数据进行拟合，给出了外加交变磁场的反演波形。
A nuclear magnetic resonance (NMR) experiment for measurement of time-dependent magnetic fields was introduced. To improve the signal-to-interference-plus-noise ratio (SINR) of NMR data, a new method for interference cancellation and noise reduction (ICNR) based on singular value decomposition (SVD) was proposed. The singular values corresponding to the radio frequency interference (RFI) signal were identified in terms of the correlation between the FID data and the reference data, and then the RFI and noise were suppressed by setting the corresponding singular values to zero. The validity of the algorithm was verified by processing the measured NMR data. The results indicated that, this method has a significantly suppression of RFI and random noise, and can well preserve the FID signal. At present, the major limitation of the proposed SVD-based ICNR technique is that the threshold value for interference cancellation needs to be manually selected. Finally, the inversion waveform of the applied alternating magnetic field was given by fitting the processed experimental data.