Wideband speech and audio coding using a new spectral replication method based on parametric stereo coding

In this paper we consider a coding scheme based on spectral replication and parametric stereo techniques. Parametric stereo technique is used to code stereo signals with a good correlation between their channels. This method is initiated to reduce redundancy between these channels. A mono downmix signal, made by linear combination of the two channels in the frequency domain, plus small side information is transmitted instead of the two channels. In the decoder both left and right channels are reconstructed from the mono downmix signal and the received parameters. We have adopted this technique to create a new spectral replication coding for mono signals. In the proposed method, we divide a mono signal into two low and high frequency parts. It is assumed that the low frequency part plays the role of the downmix signal. The results show that we can achieve 6-10% reduction in bit rate keeping the same PESQ values.