Transform-Domain Speech Bandwidth Extension

The limited speech bandwidth used in narrowband telephone systems degrades both the quality and the intelligibility of speech. This paper proposes a new transform-domain speech bandwidth extension method. The method uses discrete wavelet transform–fast Fourier transform-based data hiding technique to provide a better quality wideband speech signal. The code-excited linear prediction parameters of the missing speech are hidden within the narrowband speech signal. The hidden information is recovered at the receiving end to produce a wideband speech signal. Theoretical and simulation analyses show that the proposed method is robust to quantization and channel noises. Obtained results confirm the excellent reconstructed wideband speech quality of the proposed method over traditional methods.