Patent ID: 7069212

Claim:
An audio decoding apparatus for decoding a wideband audio signal from a bitstream containing encoded information for a narrowband audio signal, said apparatus comprising: a bitstream demultiplexer operable to demultiplex the encoded information from the bitstream; a decoder operable to decode the narrowband audio signal from the demultiplexed encoded information; an analysis filter bank operable to divide the decoded narrowband audio signal into multiple subband signals composing a first subband signal having a frequency band; a band expander operable to generate a second subband signal from the first subband signal, the second subband signal being composed of multiple subband signals each having a higher frequency band than the frequency band of the first subband signal; an aliasing remover operable to adjust a gain based on a degree of aliasing in the subband signals of the second subband signal so as to suppress aliasing components occurring in the subband signals of the second subband signal; and a real-valued calculation synthesis filter bank operable to synthesize the first subband signal and the second subband signal to obtain the wideband audio signal.