Convolutional Non-Negative Matrix Factorization for Narrowband Speech Extension in MatLab. Please read the report for a more detailed description on how CNMF can be used to extend narrowband, low-quality sound into HiFi with minimal or no side-information necessary.
YW81/Convolutional-NMF
Convolutional Non-Negative Matrix Factorization for Narrowband Speech Extension
MATLAB