Bandwidth expansion device, bandwidth expansion method, and bandwidth expansion program

摘要

A band extension apparatus that generates a high quality band extension signal without using non-linear processing is disclosed. The band extension device includes a baseband processing unit, an extension band processing unit, and a mixing unit. The baseband processing unit supplies a baseband signal limited to a predetermined frequency band. The extended band processing unit inverts the spectrum of the band signal obtained from the input signal to generate an inverted signal, an upsampler for upsampling the inverted signal, and filtering the output of the upsampler And a band-pass filter that generates, as an extension band component, a frequency band component having a frequency band substantially the same as the frequency at the high band edge of the baseband signal. The mixing unit mixes the extension band component with the baseband signal.