EFFICIENT COMBINED HARMONIC TRANSPOSITION Russian patent published in 2013 - IPC G10L21/02 

FIELD: information technology.

SUBSTANCE: invention relates to audio coding systems which employ a harmonic transposition method for high frequency reconstruction (HFR). In particular, described is a system that is configured to generate a high-frequency signal component from a low-frequency signal component. The system may include an analysis filter bank (501) configured to provide a set of analysis subband signals from the low frequency component of the signal; wherein the set of analysis subband signals comprises at least two analysis subband signals; wherein the analysis filter bank (501) has a frequency resolution of Δf. The system also includes a nonlinear processing unit (502) configured to determine a set of synthesis subband signals from the set of analysis subband signals using a transposition order P; wherein the set of synthesis subband signals comprises a portion of the set of analysis subband signals phase-shifted by a value derived from the transposition order P; and a synthesis filter bank (504) configured to generate the high frequency component of the signal from the set of synthesis subband signals; wherein the synthesis filter bank (504) has a frequency resolution of FΔf; with F being a resolution factor, with F ≥1; wherein the transposition order P is different from the resolution factor F.

EFFECT: improved audio signal quality.

28 cl, 20 dwg