Patent ID: 11967327
Assignee: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 23:
24. A method of generating a concealment audio subframe for an audio signal in a decoding device, the method comprising:
generating frequency spectra on a subframe basis where consecutive subframes of the audio signal have a property that an applied window shape of first subframe of the consecutive subframes is a mirrored version or a time reversed version of a second subframe of the consecutive subframes;
storing a signal spectrum corresponding to a second subframe of a first two consecutive subframes;
receiving a bad frame indicator for a second two consecutive subframes;
obtaining the signal spectrum;
detecting peaks of the signal spectrum on a fractional frequency scale;
estimating a phase of each of the peaks;
deriving a phase adjustment for a time reversed concealment audio subframe to apply to the peaks of the spectrum stored for a first subframe of the second two consecutive subframes based on the phase estimated;
applying the phase adjustment to the peaks of the signal spectrum to form phase adjusted peaks and to form a concealment audio subframe based on the phase adjusted peaks;
applying a time reversal to the concealment audio subframe;
combining the phase adjusted peaks with a noise spectrum of the signal spectrum to form a combined spectrum for the first subframe of the second two consecutive subframes; and
generating a synthesized concealment audio subframe based on the combined spectrum.