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

摘要

There is disclosed a band extending device generating a high-quality band extending signal without using a non-linear processing. The band extending device includes a baseband processing unit, an extended 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 includes a spectrum reversing unit for reversing the spectrum of the band signal obtained from an input signal, an up-sampler for subjecting the reversed signal to up-sampling, and a band pass filter for subjecting the output of the up-sampler to filtering so as to generate, as an extended band component, a frequency band component having a frequency substantially identical to the frequency of the high frequency end of the frequency band of the baseband signal as a low band end. The mixing unit mixes the baseband signal with the extended band component.