Weaken The Method Of Noise In The Low Field Pulsed Nmr

The low field NMR signal is quite weak and is of poor SNR(Signal to Noise Ratio). Improving SNR is one of the key factors for the realization of low-field NMR signals. It is the aim of this course to heighten the SNR.Firstly, the sources of noise are analyzed. Electromagnetic interference and the noise of preamplifier are discussed.Secondly, the methods of reducing NMR noise are discussed from two facet. One is an analog way, another is a digital way. The designing of low noise preamplifier and NMR data processing are described in this course. The circuit and shield of preamplifier are described in detail. The course focuses on the circuit optimization. Main processing steps of NMR data processing are wavelet transforms and liner prediction. The experimental results are compared with using different wavelet functions and different thresholds. The most frequent tool of this advanced signal processing techniques is linear prediction. The main arithmetics of linear prediction are the Burg method and the LP-SVD method. In this course the FB- LP method is brought forward.Finally, the experimental results are given, which prove out the analyses and arithmetics.