Bandwidth extension of signals may be defined as the deliberate process of expanding the frequency range (bandwidth) of a signal in which it contains an appreciable and useful content, and/or the frequency range in which its effects are such. Its significant advancement in recent years has led to the technology being adopted commercially in several areas including psychacoustic bass enhancement of small loudspeakers and the high frequency enhancement of perceptually coded audio. The increasing use of this technology in different areas creates a need for knowledge of the area.Written by an...