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Audio Bandwidth Extension Based on Volterra Series

In this paper,a bandwidth extension algorithm of wideband audio signal is proposed based on Volterra series with the nonlinear analysis method.The Gaussian mixture model and codebook mapping algorithms are used to adjust the spectrum envelope and energy gain of the extended audio signal separately.Test results indicate that the proposed method outperforms the existing nonlinear algorithms.When the noise-filling method used in ITU-T G.722.1C super-wideband audio codec is replaced by the proposed algorithm,the super-wideband audio quality is improved at 24 kbps.