Blind Separation of Intermolecular Zero Coherence Signals in Nuclear Magnetic Resonance

In inter-molecular multiple quantum coherences (iMQC) experiments, the iMQC signals is easily contaminated by the conventional single-quantum coherence (SQC) signals. How to get the pure iMQC signal is still an open problem for the nuclear magnetic resonance (NMR) scientists. A soft-separation method using blind source separation (BSS) technique was presented to attempt to resolve the problem for the first time. The performance of the three kinds of the different BSS techniques, algorithm for multiple unknown signals extraction (AMUSE), second order nonstationary source separation (SONS) and second order blind identification (SOBI), is evaluated. The numerical experiments show that they can separate intermolecular zero-quantum coherence (iZQC) signal very well.