Patent ID: 7205910

Claim:
A signal encoding apparatus adapted for orthogonally transforming an inputted time series signal to encode the time series signal thus transformed, the signal encoding apparatus comprising: encoding means for encoding spectrum of a limit band corresponding to a predetermined frequency band of the inputted time series signal, mapping information generating means for adaptively generating mapping information indicating a method of mapping in order to determine a time series signal of a frequency band to be extended during decoding on the basis of the mapping of the spectrum of the limit band, and output means for outputting the encoded spectrum of the limit band and the mapping information, wherein the frequency band to be extended is a frequency band higher than the predetermined frequency band; wherein the mapping is aliasing processing which allows the spectrum of the limit band to undergo aliasing at a certain position on the frequency axis, wherein the mapping information generating means adaptively determines aliasing position to generate the mapping information; and wherein the mapping information generating means normalizes the spectrum of limit band by spectrum envelope thereof to adaptively determine a position where the normalized spectrum of limit band is caused to undergo aliasing to generate the mapping information.