Audio bandwidth extension based on Grey model

A kind of audio bandwidth extension method based on Grey Model is proposed in this paper. Grey Model is utilized for estimating the envelope of high-frequency spectrum, according to the evolutionary tendency of audio spectral envelope. In addition, nearest-neighbor matching is utilized to predict the fine spectrum of high-frequency components. At last, through the envelope adjustment of high-frequency spectrum, the bandwidth extension of audio signals from wideband to super-wideband can be implemented. Objective performance evaluation indicates that the proposed method can effectively reconstruct the truncated high-frequency components and outperform the conventional method of audio bandwidth extension based on Gaussian mixture model.