Wideband audio over narrowband based on digital watermarking

This paper presents an implementation of a watermarking scheme of transmitting wideband audio stream in narrowband channel. In the implemented scheme, signal components in the upperband are encoded as side information, which is embedded into the NB (Narrowband) audio signal as a digital watermarking message in a least audible way. The watermarking method is backward compatible without need for any additional hardware and signal processing procedure. The scheme has applications in areas where high quality wideband audio is needed but the physical bandwidth is limited. The paper describes how we implemented the scheme.