  Nuclear magnetic resonance (NMR) spectroscopy has become a formidable tool
for biochemistry and medicine. Although J-coupling carries essential structural
information it may also limit the spectral resolution. Homonuclear decoupling
remains a challenging problem. In this work, we introduce a new approach that
uses a specific coupling value as prior knowledge, and Hankel property of
exponential NMR signal to achieve the broadband heteronuclear decoupling using
the low-rank method. Our results on synthetic and realistic HMQC spectra
demonstrate that the proposed method not only effectively enhances resolution
by decoupling, but also maintains sensitivity and suppresses spectral
artefacts. The approach can be combined with the non-uniform sampling, which
means that the resolution can be further improved without any extra acquisition
time
